CINXE.COM

<!DOCTYPE html> <html class="client-nojs vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available" lang="en" dir="ltr"> <head> <meta charset="UTF-8"> <title>Well logging - Wikipedia</title> <script>(function(){var className="client-js vector-feature-language-in-header-enabled vector-feature-language-in-main-page-header-disabled vector-feature-sticky-header-disabled vector-feature-page-tools-pinned-disabled vector-feature-toc-pinned-clientpref-1 vector-feature-main-menu-pinned-disabled vector-feature-limited-width-clientpref-1 vector-feature-limited-width-content-enabled vector-feature-custom-font-size-clientpref-1 vector-feature-appearance-pinned-clientpref-1 vector-feature-night-mode-enabled skin-theme-clientpref-day vector-toc-available";var cookie=document.cookie.match(/(?:^|; )enwikimwclientpreferences=([^;]+)/);if(cookie){cookie[1].split('%2C').forEach(function(pref){className=className.replace(new RegExp('(^| )'+pref.replace(/-clientpref-\w+$|[^\w-]+/g,'')+'-clientpref-\\w+( |$)'),'$1'+pref+'$2');});}document.documentElement.className=className;}());RLCONF={"wgBreakFrames":false,"wgSeparatorTransformTable":["",""],"wgDigitTransformTable":["",""],"wgDefaultDateFormat":"dmy", "wgMonthNames":["","January","February","March","April","May","June","July","August","September","October","November","December"],"wgRequestId":"63a52c4a-0d16-4b92-aa84-a6ae498e70f0","wgCanonicalNamespace":"","wgCanonicalSpecialPageName":false,"wgNamespaceNumber":0,"wgPageName":"Well_logging","wgTitle":"Well logging","wgCurRevisionId":1208100921,"wgRevisionId":1208100921,"wgArticleId":1111473,"wgIsArticle":true,"wgIsRedirect":false,"wgAction":"view","wgUserName":null,"wgUserGroups":["*"],"wgCategories":["All articles with dead external links","Articles with dead external links from June 2016","Articles with dead external links from September 2017","Articles with permanently dead external links","Articles with short description","Short description is different from Wikidata","Articles needing additional references from July 2022","All articles needing additional references","All articles with unsourced statements","Articles with unsourced statements from February 2018","Well logging", "Petroleum production","Economic geology","Oil wells","Boreholes"],"wgPageViewLanguage":"en","wgPageContentLanguage":"en","wgPageContentModel":"wikitext","wgRelevantPageName":"Well_logging","wgRelevantArticleId":1111473,"wgIsProbablyEditable":true,"wgRelevantPageIsProbablyEditable":true,"wgRestrictionEdit":[],"wgRestrictionMove":[],"wgNoticeProject":"wikipedia","wgCiteReferencePreviewsActive":false,"wgFlaggedRevsParams":{"tags":{"status":{"levels":1}}},"wgMediaViewerOnClick":true,"wgMediaViewerEnabledByDefault":true,"wgPopupsFlags":0,"wgVisualEditor":{"pageLanguageCode":"en","pageLanguageDir":"ltr","pageVariantFallbacks":"en"},"wgMFDisplayWikibaseDescriptions":{"search":true,"watchlist":true,"tagline":false,"nearby":true},"wgWMESchemaEditAttemptStepOversample":false,"wgWMEPageLength":30000,"wgRelatedArticlesCompat":[],"wgEditSubmitButtonLabelPublish":true,"wgULSPosition":"interlanguage","wgULSisCompactLinksEnabled":false,"wgVector2022LanguageInHeader":true, "wgULSisLanguageSelectorEmpty":false,"wgWikibaseItemId":"Q2383566","wgCheckUserClientHintsHeadersJsApi":["brands","architecture","bitness","fullVersionList","mobile","model","platform","platformVersion"],"GEHomepageSuggestedEditsEnableTopics":true,"wgGETopicsMatchModeEnabled":false,"wgGEStructuredTaskRejectionReasonTextInputEnabled":false,"wgGELevelingUpEnabledForUser":false};RLSTATE={"ext.globalCssJs.user.styles":"ready","site.styles":"ready","user.styles":"ready","ext.globalCssJs.user":"ready","user":"ready","user.options":"loading","ext.cite.styles":"ready","skins.vector.search.codex.styles":"ready","skins.vector.styles":"ready","skins.vector.icons":"ready","jquery.makeCollapsible.styles":"ready","ext.wikimediamessages.styles":"ready","ext.visualEditor.desktopArticleTarget.noscript":"ready","ext.uls.interlanguage":"ready","wikibase.client.init":"ready","ext.wikimediaBadges":"ready"};RLPAGEMODULES=["ext.cite.ux-enhancements","mediawiki.page.media","site","mediawiki.page.ready", "jquery.makeCollapsible","mediawiki.toc","skins.vector.js","ext.centralNotice.geoIP","ext.centralNotice.startUp","ext.gadget.ReferenceTooltips","ext.gadget.switcher","ext.urlShortener.toolbar","ext.centralauth.centralautologin","mmv.bootstrap","ext.popups","ext.visualEditor.desktopArticleTarget.init","ext.visualEditor.targetLoader","ext.echo.centralauth","ext.eventLogging","ext.wikimediaEvents","ext.navigationTiming","ext.uls.interface","ext.cx.eventlogging.campaigns","ext.cx.uls.quick.actions","wikibase.client.vector-2022","ext.checkUser.clientHints","ext.growthExperiments.SuggestedEditSession"];</script> <script>(RLQ=window.RLQ||[]).push(function(){mw.loader.impl(function(){return["user.options@12s5i",function($,jQuery,require,module){mw.user.tokens.set({"patrolToken":"+\\","watchToken":"+\\","csrfToken":"+\\"}); }];});});</script> <link rel="stylesheet" href="/w/load.php?lang=en&modules=ext.cite.styles%7Cext.uls.interlanguage%7Cext.visualEditor.desktopArticleTarget.noscript%7Cext.wikimediaBadges%7Cext.wikimediamessages.styles%7Cjquery.makeCollapsible.styles%7Cskins.vector.icons%2Cstyles%7Cskins.vector.search.codex.styles%7Cwikibase.client.init&only=styles&skin=vector-2022"> <script async="" src="/w/load.php?lang=en&modules=startup&only=scripts&raw=1&skin=vector-2022"></script> <meta name="ResourceLoaderDynamicStyles" content=""> <link rel="stylesheet" href="/w/load.php?lang=en&modules=site.styles&only=styles&skin=vector-2022"> <meta name="generator" content="MediaWiki 1.44.0-wmf.6"> <meta name="referrer" content="origin"> <meta name="referrer" content="origin-when-cross-origin"> <meta name="robots" content="max-image-preview:standard"> <meta name="format-detection" content="telephone=no"> <meta name="viewport" content="width=1120"> <meta property="og:title" content="Well logging - Wikipedia"> <meta property="og:type" content="website"> <link rel="preconnect" href="//upload.wikimedia.org"> <link rel="alternate" media="only screen and (max-width: 640px)" href="//en.m.wikipedia.org/wiki/Well_logging"> <link rel="alternate" type="application/x-wiki" title="Edit this page" href="/w/index.php?title=Well_logging&action=edit"> <link rel="apple-touch-icon" href="/static/apple-touch/wikipedia.png"> <link rel="icon" href="/static/favicon/wikipedia.ico"> <link rel="search" type="application/opensearchdescription+xml" href="/w/rest.php/v1/search" title="Wikipedia (en)"> <link rel="EditURI" type="application/rsd+xml" href="//en.wikipedia.org/w/api.php?action=rsd"> <link rel="canonical" href="https://en.wikipedia.org/wiki/Well_logging"> <link rel="license" href="https://creativecommons.org/licenses/by-sa/4.0/deed.en"> <link rel="alternate" type="application/atom+xml" title="Wikipedia Atom feed" href="/w/index.php?title=Special:RecentChanges&feed=atom"> <link rel="dns-prefetch" href="//meta.wikimedia.org" /> <link rel="dns-prefetch" href="login.wikimedia.org"> </head> <body class="skin--responsive skin-vector skin-vector-search-vue mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject mw-editable page-Well_logging rootpage-Well_logging skin-vector-2022 action-view"><a class="mw-jump-link" href="#bodyContent">Jump to content</a> <div class="vector-header-container"> <header class="vector-header mw-header"> <div class="vector-header-start"> <nav class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-dropdown" class="vector-dropdown vector-main-menu-dropdown vector-button-flush-left vector-button-flush-right" > <input type="checkbox" id="vector-main-menu-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-main-menu-dropdown" class="vector-dropdown-checkbox " aria-label="Main menu" > <label id="vector-main-menu-dropdown-label" for="vector-main-menu-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-menu mw-ui-icon-wikimedia-menu"></span> <span class="vector-dropdown-label-text">Main menu</span> </label> <div class="vector-dropdown-content"> <div id="vector-main-menu-unpinned-container" class="vector-unpinned-container"> <div id="vector-main-menu" class="vector-main-menu vector-pinnable-element"> <div class="vector-pinnable-header vector-main-menu-pinnable-header vector-pinnable-header-unpinned" data-feature-name="main-menu-pinned" data-pinnable-element-id="vector-main-menu" data-pinned-container-id="vector-main-menu-pinned-container" data-unpinned-container-id="vector-main-menu-unpinned-container" > <div class="vector-pinnable-header-label">Main menu</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-main-menu.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-main-menu.unpin">hide</button> </div> <div id="p-navigation" class="vector-menu mw-portlet mw-portlet-navigation" > <div class="vector-menu-heading"> Navigation </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-mainpage-description" class="mw-list-item"><a href="/wiki/Main_Page" title="Visit the main page [z]" accesskey="z"><span>Main page</span></a></li><li id="n-contents" class="mw-list-item"><a href="/wiki/Wikipedia:Contents" title="Guides to browsing Wikipedia"><span>Contents</span></a></li><li id="n-currentevents" class="mw-list-item"><a href="/wiki/Portal:Current_events" title="Articles related to current events"><span>Current events</span></a></li><li id="n-randompage" class="mw-list-item"><a href="/wiki/Special:Random" title="Visit a randomly selected article [x]" accesskey="x"><span>Random article</span></a></li><li id="n-aboutsite" class="mw-list-item"><a href="/wiki/Wikipedia:About" title="Learn about Wikipedia and how it works"><span>About Wikipedia</span></a></li><li id="n-contactpage" class="mw-list-item"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us" title="How to contact Wikipedia"><span>Contact us</span></a></li> </ul> </div> </div> <div id="p-interaction" class="vector-menu mw-portlet mw-portlet-interaction" > <div class="vector-menu-heading"> Contribute </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="n-help" class="mw-list-item"><a href="/wiki/Help:Contents" title="Guidance on how to use and edit Wikipedia"><span>Help</span></a></li><li id="n-introduction" class="mw-list-item"><a href="/wiki/Help:Introduction" title="Learn how to edit Wikipedia"><span>Learn to edit</span></a></li><li id="n-portal" class="mw-list-item"><a href="/wiki/Wikipedia:Community_portal" title="The hub for editors"><span>Community portal</span></a></li><li id="n-recentchanges" class="mw-list-item"><a href="/wiki/Special:RecentChanges" title="A list of recent changes to Wikipedia [r]" accesskey="r"><span>Recent changes</span></a></li><li id="n-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_upload_wizard" title="Add images or other media for use on Wikipedia"><span>Upload file</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> <a href="/wiki/Main_Page" class="mw-logo"> <img class="mw-logo-icon" src="/static/images/icons/wikipedia.png" alt="" aria-hidden="true" height="50" width="50"> <span class="mw-logo-container skin-invert"> <img class="mw-logo-wordmark" alt="Wikipedia" src="/static/images/mobile/copyright/wikipedia-wordmark-en.svg" style="width: 7.5em; height: 1.125em;"> <img class="mw-logo-tagline" alt="The Free Encyclopedia" src="/static/images/mobile/copyright/wikipedia-tagline-en.svg" width="117" height="13" style="width: 7.3125em; height: 0.8125em;"> </span> </a> </div> <div class="vector-header-end"> <div id="p-search" role="search" class="vector-search-box-vue vector-search-box-collapses vector-search-box-show-thumbnail vector-search-box-auto-expand-width vector-search-box"> <a href="/wiki/Special:Search" class="cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only search-toggle" title="Search Wikipedia [f]" accesskey="f"><span class="vector-icon mw-ui-icon-search mw-ui-icon-wikimedia-search"></span> <span>Search</span> </a> <div class="vector-typeahead-search-container"> <div class="cdx-typeahead-search cdx-typeahead-search--show-thumbnail cdx-typeahead-search--auto-expand-width"> <form action="/w/index.php" id="searchform" class="cdx-search-input cdx-search-input--has-end-button"> <div id="simpleSearch" class="cdx-search-input__input-wrapper" data-search-loc="header-moved"> <div class="cdx-text-input cdx-text-input--has-start-icon"> <input class="cdx-text-input__input" type="search" name="search" placeholder="Search Wikipedia" aria-label="Search Wikipedia" autocapitalize="sentences" title="Search Wikipedia [f]" accesskey="f" id="searchInput" > <span class="cdx-text-input__icon cdx-text-input__start-icon"></span> </div> <input type="hidden" name="title" value="Special:Search"> </div> <button class="cdx-button cdx-search-input__end-button">Search</button> </form> </div> </div> </div> <nav class="vector-user-links vector-user-links-wide" aria-label="Personal tools"> <div class="vector-user-links-main"> <div id="p-vector-user-menu-preferences" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-userpage" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-dropdown" class="vector-dropdown " title="Change the appearance of the page's font size, width, and color" > <input type="checkbox" id="vector-appearance-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-appearance-dropdown" class="vector-dropdown-checkbox " aria-label="Appearance" > <label id="vector-appearance-dropdown-label" for="vector-appearance-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-appearance mw-ui-icon-wikimedia-appearance"></span> <span class="vector-dropdown-label-text">Appearance</span> </label> <div class="vector-dropdown-content"> <div id="vector-appearance-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <div id="p-vector-user-menu-notifications" class="vector-menu mw-portlet emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> <div id="p-vector-user-menu-overflow" class="vector-menu mw-portlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en" class=""><span>Donate</span></a> </li> <li id="pt-createaccount-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:CreateAccount&returnto=Well+logging" title="You are encouraged to create an account and log in; however, it is not mandatory" class=""><span>Create account</span></a> </li> <li id="pt-login-2" class="user-links-collapsible-item mw-list-item user-links-collapsible-item"><a data-mw="interface" href="/w/index.php?title=Special:UserLogin&returnto=Well+logging" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o" class=""><span>Log in</span></a> </li> </ul> </div> </div> </div> <div id="vector-user-links-dropdown" class="vector-dropdown vector-user-menu vector-button-flush-right vector-user-menu-logged-out" title="Log in and more options" > <input type="checkbox" id="vector-user-links-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-user-links-dropdown" class="vector-dropdown-checkbox " aria-label="Personal tools" > <label id="vector-user-links-dropdown-label" for="vector-user-links-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-ellipsis mw-ui-icon-wikimedia-ellipsis"></span> <span class="vector-dropdown-label-text">Personal tools</span> </label> <div class="vector-dropdown-content"> <div id="p-personal" class="vector-menu mw-portlet mw-portlet-personal user-links-collapsible-item" title="User menu" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-sitesupport" class="user-links-collapsible-item mw-list-item"><a href="https://donate.wikimedia.org/?wmf_source=donate&wmf_medium=sidebar&wmf_campaign=en.wikipedia.org&uselang=en"><span>Donate</span></a></li><li id="pt-createaccount" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:CreateAccount&returnto=Well+logging" title="You are encouraged to create an account and log in; however, it is not mandatory"><span class="vector-icon mw-ui-icon-userAdd mw-ui-icon-wikimedia-userAdd"></span> <span>Create account</span></a></li><li id="pt-login" class="user-links-collapsible-item mw-list-item"><a href="/w/index.php?title=Special:UserLogin&returnto=Well+logging" title="You're encouraged to log in; however, it's not mandatory. [o]" accesskey="o"><span class="vector-icon mw-ui-icon-logIn mw-ui-icon-wikimedia-logIn"></span> <span>Log in</span></a></li> </ul> </div> </div> <div id="p-user-menu-anon-editor" class="vector-menu mw-portlet mw-portlet-user-menu-anon-editor" > <div class="vector-menu-heading"> Pages for logged out editors <a href="/wiki/Help:Introduction" aria-label="Learn more about editing"><span>learn more</span></a> </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="pt-anoncontribs" class="mw-list-item"><a href="/wiki/Special:MyContributions" title="A list of edits made from this IP address [y]" accesskey="y"><span>Contributions</span></a></li><li id="pt-anontalk" class="mw-list-item"><a href="/wiki/Special:MyTalk" title="Discussion about edits from this IP address [n]" accesskey="n"><span>Talk</span></a></li> </ul> </div> </div> </div> </div> </nav> </div> </header> </div> <div class="mw-page-container"> <div class="mw-page-container-inner"> <div class="vector-sitenotice-container"> <div id="siteNotice"></div> </div> <div class="vector-column-start"> <div class="vector-main-menu-container"> <div id="mw-navigation"> <nav id="mw-panel" class="vector-main-menu-landmark" aria-label="Site"> <div id="vector-main-menu-pinned-container" class="vector-pinned-container"> </div> </nav> </div> </div> <div class="vector-sticky-pinned-container"> <nav id="mw-panel-toc" aria-label="Contents" data-event-name="ui.sidebar-toc" class="mw-table-of-contents-container vector-toc-landmark"> <div id="vector-toc-pinned-container" class="vector-pinned-container"> <div id="vector-toc" class="vector-toc vector-pinnable-element"> <div class="vector-pinnable-header vector-toc-pinnable-header vector-pinnable-header-pinned" data-feature-name="toc-pinned" data-pinnable-element-id="vector-toc" > <h2 class="vector-pinnable-header-label">Contents</h2> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-toc.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-toc.unpin">hide</button> </div> <ul class="vector-toc-contents" id="mw-panel-toc-list"> <li id="toc-mw-content-text" class="vector-toc-list-item vector-toc-level-1"> <a href="#" class="vector-toc-link"> <div class="vector-toc-text">(Top)</div> </a> </li> <li id="toc-Wireline_logging" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Wireline_logging"> <div class="vector-toc-text"> <span class="vector-toc-numb">1</span> <span>Wireline logging</span> </div> </a> <button aria-controls="toc-Wireline_logging-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Wireline logging subsection</span> </button> <ul id="toc-Wireline_logging-sublist" class="vector-toc-list"> <li id="toc-History" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#History"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.1</span> <span>History</span> </div> </a> <ul id="toc-History-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Electrical_logs" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Electrical_logs"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2</span> <span>Electrical logs</span> </div> </a> <ul id="toc-Electrical_logs-sublist" class="vector-toc-list"> <li id="toc-Resistivity_log" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Resistivity_log"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2.1</span> <span>Resistivity log</span> </div> </a> <ul id="toc-Resistivity_log-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Borehole_imaging" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Borehole_imaging"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.2.2</span> <span>Borehole imaging</span> </div> </a> <ul id="toc-Borehole_imaging-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Porosity_logs" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Porosity_logs"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3</span> <span>Porosity logs</span> </div> </a> <ul id="toc-Porosity_logs-sublist" class="vector-toc-list"> <li id="toc-Density" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Density"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3.1</span> <span>Density</span> </div> </a> <ul id="toc-Density-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Neutron_porosity" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Neutron_porosity"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3.2</span> <span>Neutron porosity</span> </div> </a> <ul id="toc-Neutron_porosity-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Sonic" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Sonic"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.3.3</span> <span>Sonic</span> </div> </a> <ul id="toc-Sonic-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Lithology_logs" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Lithology_logs"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4</span> <span>Lithology logs</span> </div> </a> <ul id="toc-Lithology_logs-sublist" class="vector-toc-list"> <li id="toc-Gamma_ray" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Gamma_ray"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4.1</span> <span>Gamma ray</span> </div> </a> <ul id="toc-Gamma_ray-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Self/spontaneous_potential" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Self/spontaneous_potential"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4.2</span> <span>Self/spontaneous potential</span> </div> </a> <ul id="toc-Self/spontaneous_potential-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Miscellaneous_logs" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Miscellaneous_logs"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5</span> <span>Miscellaneous logs</span> </div> </a> <ul id="toc-Miscellaneous_logs-sublist" class="vector-toc-list"> <li id="toc-Caliper" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Caliper"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5.1</span> <span>Caliper</span> </div> </a> <ul id="toc-Caliper-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Nuclear_magnetic_resonance" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Nuclear_magnetic_resonance"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5.2</span> <span>Nuclear magnetic resonance</span> </div> </a> <ul id="toc-Nuclear_magnetic_resonance-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Spectral_acoustic_logging" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Spectral_acoustic_logging"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5.3</span> <span>Spectral acoustic logging</span> </div> </a> <ul id="toc-Spectral_acoustic_logging-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Corrosion_well_logging" class="vector-toc-list-item vector-toc-level-3"> <a class="vector-toc-link" href="#Corrosion_well_logging"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5.4</span> <span>Corrosion well logging</span> </div> </a> <ul id="toc-Corrosion_well_logging-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> </ul> </li> <li id="toc-Logging_while_drilling" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Logging_while_drilling"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Logging while drilling</span> </div> </a> <button aria-controls="toc-Logging_while_drilling-sublist" class="cdx-button cdx-button--weight-quiet cdx-button--icon-only vector-toc-toggle"> <span class="vector-icon mw-ui-icon-wikimedia-expand"></span> <span>Toggle Logging while drilling subsection</span> </button> <ul id="toc-Logging_while_drilling-sublist" class="vector-toc-list"> <li id="toc-Memory_log" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Memory_log"> <div class="vector-toc-text"> <span class="vector-toc-numb">2.1</span> <span>Memory log</span> </div> </a> <ul id="toc-Memory_log-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Coring" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Coring"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Coring</span> </div> </a> <ul id="toc-Coring-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Mudlogging" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Mudlogging"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>Mudlogging</span> </div> </a> <ul id="toc-Mudlogging-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Information_use" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Information_use"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>Information use</span> </div> </a> <ul id="toc-Information_use-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">8</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Well logging</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 20 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-20" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">20 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%AA%D8%B3%D8%AC%D9%8A%D9%84%D8%A7%D8%AA_%D8%A2%D8%A8%D8%A7%D8%B1" title="تسجيلات آبار – Arabic" lang="ar" hreflang="ar" data-title="تسجيلات آبار" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/Karotaj" title="Karotaj – Azerbaijani" lang="az" hreflang="az" data-title="Karotaj" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Bohrlochmessung" title="Bohrlochmessung – German" lang="de" hreflang="de" data-title="Bohrlochmessung" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Karotaa%C5%BE" title="Karotaaž – Estonian" lang="et" hreflang="et" data-title="Karotaaž" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Perfilaje_de_pozo" title="Perfilaje de pozo – Spanish" lang="es" hreflang="es" data-title="Perfilaje de pozo" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%DA%86%D8%A7%D9%87_%D9%BE%DB%8C%D9%85%D8%A7%DB%8C%DB%8C" title="چاه پیمایی – Persian" lang="fa" hreflang="fa" data-title="چاه پیمایی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Diagraphie" title="Diagraphie – French" lang="fr" hreflang="fr" data-title="Diagraphie" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D4%BF%D5%A1%D6%80%D5%B8%D5%BF%D5%A1%D5%AA" title="Կարոտաժ – Armenian" lang="hy" hreflang="hy" data-title="Կարոտաժ" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Pencatatan_sumur" title="Pencatatan sumur – Indonesian" lang="id" hreflang="id" data-title="Pencatatan sumur" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Logging" title="Logging – Italian" lang="it" hreflang="it" data-title="Logging" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%9A%D0%B0%D1%80%D0%BE%D1%82%D0%B0%D0%B6" title="Каротаж – Kazakh" lang="kk" hreflang="kk" data-title="Каротаж" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ky mw-list-item"><a href="https://ky.wikipedia.org/wiki/%D0%9A%D0%B0%D1%80%D0%BE%D1%82%D0%B0%D0%B6" title="Каротаж – Kyrgyz" lang="ky" hreflang="ky" data-title="Каротаж" data-language-autonym="Кыргызча" data-language-local-name="Kyrgyz" class="interlanguage-link-target"><span>Кыргызча</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Karot%C4%81%C5%BEa" title="Karotāža – Latvian" lang="lv" hreflang="lv" data-title="Karotāža" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Karota%C5%BC" title="Karotaż – Polish" lang="pl" hreflang="pl" data-title="Karotaż" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9A%D0%B0%D1%80%D0%BE%D1%82%D0%B0%D0%B6" title="Каротаж – Russian" lang="ru" hreflang="ru" data-title="Каротаж" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Geofyzik%C3%A1lne_meranie_vo_vrtoch" title="Geofyzikálne meranie vo vrtoch – Slovak" lang="sk" hreflang="sk" data-title="Geofyzikálne meranie vo vrtoch" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-tg mw-list-item"><a href="https://tg.wikipedia.org/wiki/%D0%9A%D0%B0%D1%80%D0%BE%D1%82%D0%B0%D0%B6" title="Каротаж – Tajik" lang="tg" hreflang="tg" data-title="Каротаж" data-language-autonym="Тоҷикӣ" data-language-local-name="Tajik" class="interlanguage-link-target"><span>Тоҷикӣ</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9A%D0%B0%D1%80%D0%BE%D1%82%D0%B0%D0%B6" title="Каротаж – Ukrainian" lang="uk" hreflang="uk" data-title="Каротаж" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/%C4%90%E1%BB%8Ba_v%E1%BA%ADt_l%C3%BD_h%E1%BB%91_khoan" title="Địa vật lý hố khoan – Vietnamese" lang="vi" hreflang="vi" data-title="Địa vật lý hố khoan" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E6%B5%8B%E4%BA%95" title="测井 – Chinese" lang="zh" hreflang="zh" data-title="测井" data-language-autonym="中文" data-language-local-name="Chinese" class="interlanguage-link-target"><span>中文</span></a></li> </ul> <div class="after-portlet after-portlet-lang"><span class="wb-langlinks-edit wb-langlinks-link"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q2383566#sitelinks-wikipedia" title="Edit interlanguage links" class="wbc-editpage">Edit links</a></span></div> </div> </div> </div> </header> <div class="vector-page-toolbar"> <div class="vector-page-toolbar-container"> <div id="left-navigation"> <nav aria-label="Namespaces"> <div id="p-associated-pages" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-associated-pages" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-nstab-main" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Well_logging" title="View the content page [c]" accesskey="c"><span>Article</span></a></li><li id="ca-talk" class="vector-tab-noicon mw-list-item"><a href="/wiki/Talk:Well_logging" rel="discussion" title="Discuss improvements to the content page [t]" accesskey="t"><span>Talk</span></a></li> </ul> </div> </div> <div id="vector-variants-dropdown" class="vector-dropdown emptyPortlet" > <input type="checkbox" id="vector-variants-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-variants-dropdown" class="vector-dropdown-checkbox " aria-label="Change language variant" > <label id="vector-variants-dropdown-label" for="vector-variants-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">English</span> </label> <div class="vector-dropdown-content"> <div id="p-variants" class="vector-menu mw-portlet mw-portlet-variants emptyPortlet" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> </ul> </div> </div> </div> </div> </nav> </div> <div id="right-navigation" class="vector-collapsible"> <nav aria-label="Views"> <div id="p-views" class="vector-menu vector-menu-tabs mw-portlet mw-portlet-views" > <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-view" class="selected vector-tab-noicon mw-list-item"><a href="/wiki/Well_logging"><span>Read</span></a></li><li id="ca-edit" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Well_logging&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-history" class="vector-tab-noicon mw-list-item"><a href="/w/index.php?title=Well_logging&action=history" title="Past revisions of this page [h]" accesskey="h"><span>View history</span></a></li> </ul> </div> </div> </nav> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-dropdown" class="vector-dropdown vector-page-tools-dropdown" > <input type="checkbox" id="vector-page-tools-dropdown-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-tools-dropdown" class="vector-dropdown-checkbox " aria-label="Tools" > <label id="vector-page-tools-dropdown-label" for="vector-page-tools-dropdown-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet" aria-hidden="true" ><span class="vector-dropdown-label-text">Tools</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-tools-unpinned-container" class="vector-unpinned-container"> <div id="vector-page-tools" class="vector-page-tools vector-pinnable-element"> <div class="vector-pinnable-header vector-page-tools-pinnable-header vector-pinnable-header-unpinned" data-feature-name="page-tools-pinned" data-pinnable-element-id="vector-page-tools" data-pinned-container-id="vector-page-tools-pinned-container" data-unpinned-container-id="vector-page-tools-unpinned-container" > <div class="vector-pinnable-header-label">Tools</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-page-tools.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-page-tools.unpin">hide</button> </div> <div id="p-cactions" class="vector-menu mw-portlet mw-portlet-cactions emptyPortlet vector-has-collapsible-items" title="More options" > <div class="vector-menu-heading"> Actions </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="ca-more-view" class="selected vector-more-collapsible-item mw-list-item"><a href="/wiki/Well_logging"><span>Read</span></a></li><li id="ca-more-edit" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Well_logging&action=edit" title="Edit this page [e]" accesskey="e"><span>Edit</span></a></li><li id="ca-more-history" class="vector-more-collapsible-item mw-list-item"><a href="/w/index.php?title=Well_logging&action=history"><span>View history</span></a></li> </ul> </div> </div> <div id="p-tb" class="vector-menu mw-portlet mw-portlet-tb" > <div class="vector-menu-heading"> General </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-whatlinkshere" class="mw-list-item"><a href="/wiki/Special:WhatLinksHere/Well_logging" title="List of all English Wikipedia pages containing links to this page [j]" accesskey="j"><span>What links here</span></a></li><li id="t-recentchangeslinked" class="mw-list-item"><a href="/wiki/Special:RecentChangesLinked/Well_logging" rel="nofollow" title="Recent changes in pages linked from this page [k]" accesskey="k"><span>Related changes</span></a></li><li id="t-upload" class="mw-list-item"><a href="/wiki/Wikipedia:File_Upload_Wizard" title="Upload files [u]" accesskey="u"><span>Upload file</span></a></li><li id="t-specialpages" class="mw-list-item"><a href="/wiki/Special:SpecialPages" title="A list of all special pages [q]" accesskey="q"><span>Special pages</span></a></li><li id="t-permalink" class="mw-list-item"><a href="/w/index.php?title=Well_logging&oldid=1208100921" title="Permanent link to this revision of this page"><span>Permanent link</span></a></li><li id="t-info" class="mw-list-item"><a href="/w/index.php?title=Well_logging&action=info" title="More information about this page"><span>Page information</span></a></li><li id="t-cite" class="mw-list-item"><a href="/w/index.php?title=Special:CiteThisPage&page=Well_logging&id=1208100921&wpFormIdentifier=titleform" title="Information on how to cite this page"><span>Cite this page</span></a></li><li id="t-urlshortener" class="mw-list-item"><a href="/w/index.php?title=Special:UrlQ%C4%B1sald%C4%B1c%C4%B1s%C4%B1&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FWell_logging"><span>Get shortened URL</span></a></li><li id="t-urlshortener-qrcode" class="mw-list-item"><a href="/w/index.php?title=Special:QrKodu&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FWell_logging"><span>Download QR code</span></a></li> </ul> </div> </div> <div id="p-coll-print_export" class="vector-menu mw-portlet mw-portlet-coll-print_export" > <div class="vector-menu-heading"> Print/export </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="coll-download-as-rl" class="mw-list-item"><a href="/w/index.php?title=Special:DownloadAsPdf&page=Well_logging&action=show-download-screen" title="Download this page as a PDF file"><span>Download as PDF</span></a></li><li id="t-print" class="mw-list-item"><a href="/w/index.php?title=Well_logging&printable=yes" title="Printable version of this page [p]" accesskey="p"><span>Printable version</span></a></li> </ul> </div> </div> <div id="p-wikibase-otherprojects" class="vector-menu mw-portlet mw-portlet-wikibase-otherprojects" > <div class="vector-menu-heading"> In other projects </div> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li id="t-wikibase" class="wb-otherproject-link wb-otherproject-wikibase-dataitem mw-list-item"><a href="https://www.wikidata.org/wiki/Special:EntityPage/Q2383566" title="Structured data on this page hosted by Wikidata [g]" accesskey="g"><span>Wikidata item</span></a></li> </ul> </div> </div> </div> </div> </div> </div> </nav> </div> </div> </div> <div class="vector-column-end"> <div class="vector-sticky-pinned-container"> <nav class="vector-page-tools-landmark" aria-label="Page tools"> <div id="vector-page-tools-pinned-container" class="vector-pinned-container"> </div> </nav> <nav class="vector-appearance-landmark" aria-label="Appearance"> <div id="vector-appearance-pinned-container" class="vector-pinned-container"> <div id="vector-appearance" class="vector-appearance vector-pinnable-element"> <div class="vector-pinnable-header vector-appearance-pinnable-header vector-pinnable-header-pinned" data-feature-name="appearance-pinned" data-pinnable-element-id="vector-appearance" data-pinned-container-id="vector-appearance-pinned-container" data-unpinned-container-id="vector-appearance-unpinned-container" > <div class="vector-pinnable-header-label">Appearance</div> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-pin-button" data-event-name="pinnable-header.vector-appearance.pin">move to sidebar</button> <button class="vector-pinnable-header-toggle-button vector-pinnable-header-unpin-button" data-event-name="pinnable-header.vector-appearance.unpin">hide</button> </div> </div> </div> </nav> </div> </div> <div id="bodyContent" class="vector-body" aria-labelledby="firstHeading" data-mw-ve-target-container> <div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Detailed record of borehole contents</div> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Well_logging" title="Special:EditPage/Well logging">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Well+logging%22">"Well logging"</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Well+logging%22+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Well+logging%22&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Well+logging%22+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Well+logging%22">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Well+logging%22&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">July 2022</span>)</i></span><span class="hide-when-compact"><i> (<small><a href="/wiki/Help:Maintenance_template_removal" title="Help:Maintenance template removal">Learn how and when to remove this message</a></small>)</i></span></div></td></tr></tbody></table> <style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl ol,.mw-parser-output .hlist dl ul,.mw-parser-output .hlist ol dl,.mw-parser-output .hlist ol ol,.mw-parser-output .hlist ol ul,.mw-parser-output .hlist ul dl,.mw-parser-output .hlist ul ol,.mw-parser-output .hlist ul ul{display:inline}.mw-parser-output .hlist .mw-empty-li{display:none}.mw-parser-output .hlist dt::after{content:": "}.mw-parser-output .hlist dd::after,.mw-parser-output .hlist li::after{content:" · ";font-weight:bold}.mw-parser-output .hlist dd:last-child::after,.mw-parser-output .hlist dt:last-child::after,.mw-parser-output .hlist li:last-child::after{content:none}.mw-parser-output .hlist dd dd:first-child::before,.mw-parser-output .hlist dd dt:first-child::before,.mw-parser-output .hlist dd li:first-child::before,.mw-parser-output .hlist dt dd:first-child::before,.mw-parser-output .hlist dt dt:first-child::before,.mw-parser-output .hlist dt li:first-child::before,.mw-parser-output .hlist li dd:first-child::before,.mw-parser-output .hlist li dt:first-child::before,.mw-parser-output .hlist li li:first-child::before{content:" (";font-weight:normal}.mw-parser-output .hlist dd dd:last-child::after,.mw-parser-output .hlist dd dt:last-child::after,.mw-parser-output .hlist dd li:last-child::after,.mw-parser-output .hlist dt dd:last-child::after,.mw-parser-output .hlist dt dt:last-child::after,.mw-parser-output .hlist dt li:last-child::after,.mw-parser-output .hlist li dd:last-child::after,.mw-parser-output .hlist li dt:last-child::after,.mw-parser-output .hlist li li:last-child::after{content:")";font-weight:normal}.mw-parser-output .hlist ol{counter-reset:listitem}.mw-parser-output .hlist ol>li{counter-increment:listitem}.mw-parser-output .hlist ol>li::before{content:" "counter(listitem)"\a0 "}.mw-parser-output .hlist dd ol>li:first-child::before,.mw-parser-output .hlist dt ol>li:first-child::before,.mw-parser-output .hlist li ol>li:first-child::before{content:" ("counter(listitem)"\a0 "}</style><style data-mw-deduplicate="TemplateStyles:r1126788409">.mw-parser-output .plainlist ol,.mw-parser-output .plainlist ul{line-height:inherit;list-style:none;margin:0;padding:0}.mw-parser-output .plainlist ol li,.mw-parser-output .plainlist ul li{margin-bottom:0}</style><style data-mw-deduplicate="TemplateStyles:r1246091330">.mw-parser-output .sidebar{width:22em;float:right;clear:right;margin:0.5em 0 1em 1em;background:var(--background-color-neutral-subtle,#f8f9fa);border:1px solid var(--border-color-base,#a2a9b1);padding:0.2em;text-align:center;line-height:1.4em;font-size:88%;border-collapse:collapse;display:table}body.skin-minerva .mw-parser-output .sidebar{display:table!important;float:right!important;margin:0.5em 0 1em 1em!important}.mw-parser-output .sidebar-subgroup{width:100%;margin:0;border-spacing:0}.mw-parser-output .sidebar-left{float:left;clear:left;margin:0.5em 1em 1em 0}.mw-parser-output .sidebar-none{float:none;clear:both;margin:0.5em 1em 1em 0}.mw-parser-output .sidebar-outer-title{padding:0 0.4em 0.2em;font-size:125%;line-height:1.2em;font-weight:bold}.mw-parser-output .sidebar-top-image{padding:0.4em}.mw-parser-output .sidebar-top-caption,.mw-parser-output .sidebar-pretitle-with-top-image,.mw-parser-output .sidebar-caption{padding:0.2em 0.4em 0;line-height:1.2em}.mw-parser-output .sidebar-pretitle{padding:0.4em 0.4em 0;line-height:1.2em}.mw-parser-output .sidebar-title,.mw-parser-output .sidebar-title-with-pretitle{padding:0.2em 0.8em;font-size:145%;line-height:1.2em}.mw-parser-output .sidebar-title-with-pretitle{padding:0.1em 0.4em}.mw-parser-output .sidebar-image{padding:0.2em 0.4em 0.4em}.mw-parser-output .sidebar-heading{padding:0.1em 0.4em}.mw-parser-output .sidebar-content{padding:0 0.5em 0.4em}.mw-parser-output .sidebar-content-with-subgroup{padding:0.1em 0.4em 0.2em}.mw-parser-output .sidebar-above,.mw-parser-output .sidebar-below{padding:0.3em 0.8em;font-weight:bold}.mw-parser-output .sidebar-collapse .sidebar-above,.mw-parser-output .sidebar-collapse .sidebar-below{border-top:1px solid #aaa;border-bottom:1px solid #aaa}.mw-parser-output .sidebar-navbar{text-align:right;font-size:115%;padding:0 0.4em 0.4em}.mw-parser-output .sidebar-list-title{padding:0 0.4em;text-align:left;font-weight:bold;line-height:1.6em;font-size:105%}.mw-parser-output .sidebar-list-title-c{padding:0 0.4em;text-align:center;margin:0 3.3em}@media(max-width:640px){body.mediawiki .mw-parser-output .sidebar{width:100%!important;clear:both;float:none!important;margin-left:0!important;margin-right:0!important}}body.skin--responsive .mw-parser-output .sidebar a>img{max-width:none!important}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-list-title,html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle{background:transparent!important}html.skin-theme-clientpref-night .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-list-title,html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle{background:transparent!important}html.skin-theme-clientpref-os .mw-parser-output .sidebar:not(.notheme) .sidebar-title-with-pretitle a{color:var(--color-progressive)!important}}@media print{body.ns-0 .mw-parser-output .sidebar{display:none!important}}</style><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><table class="sidebar nomobile nowraplinks plainlist"><tbody><tr><th class="sidebar-title" style="background:#f0f0f0; display:block;margin-bottom:0.3em;"><a class="mw-selflink selflink">Well logging</a> methods</th></tr><tr><td class="sidebar-content"> <div class="hlist"> <ul><li><a href="/wiki/Caliper_log" title="Caliper log">Caliper</a></li> <li><a href="/wiki/Density_logging" title="Density logging">Density</a></li> <li><a href="/wiki/Gamma_ray_logging" title="Gamma ray logging"><span class="wrap">Gamma ray</span></a></li> <li><a href="/wiki/Mud_logging" title="Mud logging">Mud</a></li> <li><a href="/wiki/Resistivity_logging" title="Resistivity logging">Resistivity</a></li> <li><a href="/wiki/Sonic_logging" title="Sonic logging">Sonic</a></li> <li><a href="/wiki/Spontaneous_potential_logging" title="Spontaneous potential logging">Spontaneous potential</a></li> <li><a href="/wiki/Logging_while_drilling" title="Logging while drilling">Logging while drilling <span style="font-size:85%;">(LWD)</span></a></li> <li><a href="/wiki/Measurement_while_drilling" title="Measurement while drilling">Measurement while drilling <span style="font-size:85%;">(MWD)</span></a></li> <li><a href="/wiki/Nuclear_magnetic_resonance_logging" title="Nuclear magnetic resonance logging">Nuclear magnetic resonance <span style="font-size:85%;">(NMR)</span></a></li></ul> </div></td> </tr><tr><td class="sidebar-navbar"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Well_logging" title="Template:Well logging"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Well_logging" title="Template talk:Well logging"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Well_logging" title="Special:EditPage/Template:Well logging"><abbr title="Edit this template">e</abbr></a></li></ul></div></td></tr></tbody></table> <p><b>Well logging</b>, also known as <b>borehole logging</b> is the practice of making a detailed record (a <i>well log</i>) of the <a href="/wiki/Formation_(stratigraphy)" class="mw-redirect" title="Formation (stratigraphy)">geologic formations</a> penetrated by a <a href="/wiki/Borehole" title="Borehole">borehole</a>. The log may be based either on visual inspection of samples brought to the surface (<i>geological</i> logs) or on physical measurements made by instruments lowered into the hole (<i>geophysical</i> logs). Some types of geophysical well logs can be done during any phase of a well's history: drilling, completing, producing, or abandoning. Well logging is performed in boreholes drilled for the <a href="/wiki/Hydrocarbon_exploration" title="Hydrocarbon exploration">oil and gas</a>, <a href="/wiki/Groundwater" title="Groundwater">groundwater</a>, <a href="/wiki/Mineral_exploration" class="mw-redirect" title="Mineral exploration">mineral</a> and <a href="/wiki/Geothermal_exploration" title="Geothermal exploration">geothermal</a> exploration, as well as part of environmental and <a href="/wiki/Geotechnical" class="mw-redirect" title="Geotechnical">geotechnical</a> studies. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Wireline_logging">Wireline logging</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=1" title="Edit section: Wireline logging"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Loggrdenres.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Loggrdenres.jpg/220px-Loggrdenres.jpg" decoding="async" width="220" height="1143" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Loggrdenres.jpg/330px-Loggrdenres.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5f/Loggrdenres.jpg/440px-Loggrdenres.jpg 2x" data-file-width="526" data-file-height="2734" /></a><figcaption>Wireline log consisting of caliper, density and resistivity logs</figcaption></figure> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:LI1LOG.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/LI1LOG.jpg/220px-LI1LOG.jpg" decoding="async" width="220" height="686" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/5/5e/LI1LOG.jpg/330px-LI1LOG.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/5/5e/LI1LOG.jpg/440px-LI1LOG.jpg 2x" data-file-width="1469" data-file-height="4581" /></a><figcaption>Wireline log consisting of a complete set of logs</figcaption></figure> <p>Different industries, as <a href="/wiki/Mining" title="Mining">mining</a>, <a href="/wiki/Petroleum" title="Petroleum">oil</a> and <a href="/wiki/Natural_Gas" class="mw-redirect" title="Natural Gas">gas</a> uses <a href="/wiki/Wireline_(cabling)" title="Wireline (cabling)">wireline</a> logging to obtain a continuous record of a formation's <a href="/wiki/Petrophysics" title="Petrophysics">rock properties</a>, also, groundwater consultants.<sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> Wireline logging can be defined as being "The acquisition and analysis of geophysical data performed as a function of well bore depth, together with the provision of related services." Note that "wireline logging" and "mud logging" are not the same, yet are closely linked through the integration of the data sets. The measurements are made referenced to "TAH" - True Along Hole depth: these and the associated analysis can then be used to infer further properties, such as <a href="/wiki/Water_content" title="Water content">hydrocarbon saturation</a> and <a href="/wiki/Well_control" title="Well control">formation pressure</a>, and to make further <a href="/wiki/Drilling_engineering" title="Drilling engineering">drilling</a> and <a href="/wiki/Hydrocarbon_exploration" title="Hydrocarbon exploration">production</a> decisions. </p><p>Wireline logging is performed by lowering a 'logging tool' - or a string of one or more instruments - on the end of a wireline into an <a href="/wiki/Oil_well" title="Oil well">oil well</a> (or borehole) and recording petrophysical properties using a variety of sensors. Logging tools developed over the years measure the natural gamma ray, electrical, acoustic, stimulated radioactive responses, electromagnetic, nuclear magnetic resonance, pressure and other properties of the rocks and their contained fluids. For this article, they are broadly broken down by the main property that they respond to. </p><p>The data itself is recorded either at surface (real-time mode), or in the hole (memory mode) to an electronic data format and then either a printed record or electronic presentation called a "well log" is provided to the client, along with an electronic copy of the raw data. Well logging operations can either be performed during the drilling process (see Logging While Drilling), to provide real-time information about the formations being penetrated by the borehole, or once the well has reached Total Depth and the whole depth of the borehole can be logged. </p><p>Real-time data is recorded directly against measured cable depth. Memory data is recorded against time, and then depth data is simultaneously measured against time. The two data sets are then merged using the common time base to create an instrument response versus depth log. Memory recorded depth can also be corrected in exactly the same way as real-time corrections are made, so there should be no difference in the attainable TAH accuracy. </p><p>The measured cable depth can be derived from a number of different measurements, but is usually either recorded based on a calibrated wheel counter, or (more accurately) using magnetic marks which provide calibrated increments of cable length. The measurements made must then be corrected for elastic stretch and temperature.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> </p><p>There are many types of wireline logs and they can be categorized either by their function or by the technology that they use. "Open hole logs" are run before the oil or gas well is lined with pipe or cased. "Cased hole logs" are run after the well is lined with casing or production pipe.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>Wireline logs can be divided into broad categories based on the physical properties measured. </p> <div class="mw-heading mw-heading3"><h3 id="History">History</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=2" title="Edit section: History"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Conrad_and_Marcel_Schlumberger" class="mw-redirect" title="Conrad and Marcel Schlumberger">Conrad and Marcel Schlumberger</a>, who founded <a href="/wiki/Schlumberger" title="Schlumberger">Schlumberger Limited</a> in 1926, are considered the inventors of electric well logging. Conrad developed the <a href="/wiki/Schlumberger_array" class="mw-redirect" title="Schlumberger array">Schlumberger array</a>, which was a technique for prospecting for <a href="/wiki/Metal" title="Metal">metal</a> <a href="/wiki/Ore" title="Ore">ore</a> deposits, and the brothers adapted that surface technique to subsurface applications. On September 5, 1927, a crew working for Schlumberger lowered an electric sonde or tool down a well in Pechelbronn, Alsace, France creating the first <a href="/wiki/Well_log" class="mw-redirect" title="Well log">well log</a>. In modern terms, the first log was a <a href="/wiki/Resistivity_log" class="mw-redirect" title="Resistivity log">resistivity log</a> that could be described as 3.5-meter upside-down lateral log.<sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> </p><p>In 1931, <a href="/wiki/Henri_George_Doll" title="Henri George Doll">Henri George Doll</a> and G. Dechatre, working for Schlumberger, discovered that the <a href="/wiki/Galvanometer" title="Galvanometer">galvanometer</a> wiggled even when no current was being passed through the logging cables down in the well. This led to the discovery of the <a href="/wiki/Spontaneous_potential" title="Spontaneous potential">spontaneous potential</a> (SP) which was as important as the ability to measure <a href="/wiki/Resistivity" class="mw-redirect" title="Resistivity">resistivity</a>. The SP effect was produced naturally by the borehole <a href="/wiki/Mud" title="Mud">mud</a> at the boundaries of <a href="/wiki/Permeability_(earth_sciences)" class="mw-redirect" title="Permeability (earth sciences)">permeable</a> beds. By simultaneously recording SP and resistivity, loggers could distinguish between permeable oil-bearing beds and impermeable nonproducing beds.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> </p><p>In 1940, Schlumberger invented the <a href="/wiki/Spontaneous_potential" title="Spontaneous potential">spontaneous potential</a> <a href="/wiki/Dipmeter" class="mw-redirect" title="Dipmeter">dipmeter</a>; this instrument allowed the calculation of the <a href="/wiki/Strike_and_dip" title="Strike and dip">dip</a> and direction of the dip of a layer. The basic dipmeter was later enhanced by the resistivity dipmeter (1947) and the continuous resistivity dipmeter (1952). </p><p>Oil-based mud (OBM) was first used in Rangely Field, Colorado, in 1948. Normal electric logs require a conductive or water-based mud, but OBMs are nonconductive. The solution to this problem was the induction log, developed in the late 1940s. </p><p>The introduction of the <a href="/wiki/Transistor" title="Transistor">transistor</a> and <a href="/wiki/Integrated_circuits" class="mw-redirect" title="Integrated circuits">integrated circuits</a> in the 1960s made electric logs vastly more reliable. Computerization allowed much faster log processing, and dramatically expanded log data-gathering capacity. The 1970s brought more logs and computers. These included combo type logs where <a href="/wiki/Resistivity_logs" class="mw-redirect" title="Resistivity logs">resistivity logs</a> and porosity logs were recorded in one pass in the borehole. </p><p>The two types of porosity logs (acoustic logs and nuclear logs) date originally from the 1940s. <a href="/wiki/Sonic_logs" class="mw-redirect" title="Sonic logs">Sonic logs</a> grew out of technology developed during World War II. Nuclear logging has supplemented acoustic logging, but acoustic or sonic logs are still run on some combination logging tools. </p><p>Nuclear logging was initially developed to measure the natural gamma radiation emitted by underground formations. However, the industry quickly moved to logs that actively bombard rocks with <a href="/wiki/Nuclear_particles" class="mw-redirect" title="Nuclear particles">nuclear particles</a>. The <a href="/wiki/Gamma_ray" title="Gamma ray">gamma ray</a> log, measuring the natural radioactivity, was introduced by Well Surveys Inc. in 1939, and the WSI <a href="/wiki/Neutron" title="Neutron">neutron</a> log came in 1941. The gamma ray log is particularly useful as shale beds which often provide a relatively low permeability cap over hydrocarbon reservoirs usually display a higher level of gamma radiation. These logs were important because they can be used in cased wells (wells with production casing). WSI quickly became part of Lane-Wells. During <a href="/wiki/World_War_II" title="World War II">World War II</a>, the US Government gave a near wartime monopoly on open-hole logging to <a href="/wiki/Schlumberger" title="Schlumberger">Schlumberger</a>, and a monopoly on cased-hole logging to <a href="/w/index.php?title=Lane-Wells&action=edit&redlink=1" class="new" title="Lane-Wells (page does not exist)">Lane-Wells</a>.<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> Nuclear logs continued to evolve after the war. </p><p>After the discovery of nuclear magnetic resonance by Bloch and Purcell in 1946, the <a href="/wiki/Nuclear_magnetic_resonance" title="Nuclear magnetic resonance">nuclear magnetic resonance</a> log using the Earth's field was developed in the early 1950s by Chevron and Schlumberger.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Nicolaas_Bloembergen" title="Nicolaas Bloembergen">Nicolaas Bloembergen</a> filed the Schlumberger patent in 1966.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup> The NMR log was a scientific success but an engineering failure. More recent engineering developments by NUMAR (a subsidiary of <a href="/wiki/Halliburton" title="Halliburton">Halliburton</a>) in the 1990s has resulted in continuous NMR logging technology which is now applied in the oil and gas, water and metal exploration industry.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup><sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (February 2018)">citation needed</span></a></i>]</sup> </p><p>Many modern oil and gas wells are drilled directionally. At first, loggers had to run their tools somehow attached to the drill pipe if the well was not vertical. Modern techniques now permit continuous information at the surface. This is known as <a href="/wiki/Logging_while_drilling" title="Logging while drilling">logging while drilling</a> (LWD) or <a href="/wiki/Measurement-while-drilling" class="mw-redirect" title="Measurement-while-drilling">measurement-while-drilling</a> (MWD). MWD logs use <a href="/wiki/Mud_pulse_technology" class="mw-redirect" title="Mud pulse technology">mud pulse technology</a> to transmit data from the tools on the bottom of the <a href="/wiki/Drill_string" title="Drill string">drillstring</a> to the processors at the surface. </p> <div class="mw-heading mw-heading3"><h3 id="Electrical_logs">Electrical logs</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=3" title="Edit section: Electrical logs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Resistivity_log">Resistivity log</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=4" title="Edit section: Resistivity log"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Resistivity_logging" title="Resistivity logging">Resistivity logging</a></div> <p>Resistivity logging measures the subsurface electrical resistivity, which is the ability to impede the flow of electric current. This helps to differentiate between formations filled with salty waters (good conductors of electricity) and those filled with hydrocarbons (poor conductors of electricity). Resistivity and porosity measurements are used to calculate water saturation. Resistivity is expressed in ohms.meter (Ω⋅m), and is frequently charted on a logarithm scale versus depth because of the large range of resistivity. The distance from the borehole penetrated by the current varies with the tool, from a few centimeters to one meter. </p> <div class="mw-heading mw-heading4"><h4 id="Borehole_imaging">Borehole imaging</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=5" title="Edit section: Borehole imaging"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Borehole_Image_Logs" class="mw-redirect" title="Borehole Image Logs">Borehole Image Logs</a></div> <p>The term "borehole imaging" refers to those logging and data-processing methods that are used to produce centimeter-scale images of the borehole wall and the rocks that make it up. The context is, therefore, that of open hole, but some of the tools are closely related to their cased-hole equivalents. Borehole imaging has been one of the most rapidly advancing technologies in wireline well logging. The applications range from detailed reservoir description through reservoir performance to enhanced hydrocarbon recovery. Specific applications are fracture identification,<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> analysis of small-scale sedimentological features, evaluation of net pay in thinly bedded formations, and the identification of breakouts (irregularities in the borehole wall that are aligned with the minimum horizontal stress and appear where stresses around the wellbore exceed the compressive strength of the rock).<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> The subject area can be classified into four parts: </p> <ol><li>Optical imaging</li> <li>Acoustic imaging</li> <li>Electrical imaging</li> <li>Methods that draw on both acoustic and electrical imaging techniques using the same logging tool</li></ol> <div class="mw-heading mw-heading3"><h3 id="Porosity_logs">Porosity logs</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=6" title="Edit section: Porosity logs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p><a href="/wiki/Porosity" title="Porosity">Porosity</a> logs measure the fraction or percentage of pore volume in a volume of rock. Most porosity logs use either <a href="/wiki/Acoustics" title="Acoustics">acoustic</a> or <a href="/wiki/Nuclear_physics" title="Nuclear physics">nuclear</a> technology. Acoustic logs measure characteristics of sound waves propagated through the well-bore environment. Nuclear logs utilize nuclear reactions that take place in the downhole logging instrument or in the formation. Nuclear logs include density logs and neutron logs, as well as gamma ray logs which are used for correlation. <sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> The basic principle behind the use of nuclear technology is that a neutron source placed near the formation whose porosity is being measured will result in neutrons being scattered by the hydrogen atoms, largely those present in the formation fluid. Since there is little difference in the neutrons scattered by hydrocarbons or water, the porosity measured gives a figure close to the true physical porosity whereas the figure obtained from electrical resistivity measurements is that due to the conductive formation fluid. The difference between neutron porosity and electrical porosity measurements therefore indicates the presence of hydrocarbons in the formation fluid. </p> <div class="mw-heading mw-heading4"><h4 id="Density">Density</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=7" title="Edit section: Density"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Density_logging" title="Density logging">Density logging</a></div> <p>The density log measures the <a href="/wiki/Bulk_density" title="Bulk density">bulk density</a> of a formation by bombarding it with a radioactive source and measuring the resulting gamma ray count after the effects of <a href="/wiki/Compton_Scattering" class="mw-redirect" title="Compton Scattering">Compton Scattering</a> and <a href="/wiki/Photoelectric_effect" title="Photoelectric effect">Photoelectric absorption</a>. This bulk density can then be used to determine porosity. </p> <div class="mw-heading mw-heading4"><h4 id="Neutron_porosity">Neutron porosity</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=8" title="Edit section: Neutron porosity"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Formation_evaluation_neutron_porosity" title="Formation evaluation neutron porosity">Formation evaluation neutron porosity</a></div> <p>The neutron porosity log works by bombarding a formation with high energy <a href="/wiki/Neutron_temperature" title="Neutron temperature">epithermal neutrons</a> that lose energy through <a href="/wiki/Elastic_scattering" title="Elastic scattering">elastic scattering</a> to near thermal levels before being absorbed by the <a href="/wiki/Atomic_nucleus" title="Atomic nucleus">nuclei</a> of the formation atoms. Depending on the particular type of neutron logging tool, either the <a href="/wiki/Gamma_ray" title="Gamma ray">gamma ray</a> of capture, scattered thermal neutrons or scattered, higher energy epithermal neutrons are detected.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> The neutron porosity log is predominantly sensitive to the quantity of <a href="/wiki/Hydrogen_atom" title="Hydrogen atom">hydrogen atoms</a> in a particular formation, which generally corresponds to rock porosity. </p><p><a href="/wiki/Boron" title="Boron">Boron</a> is known to cause anomalously low neutron tool count rates due to it having a high capture cross section for thermal neutron absorption.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> An increase in hydrogen concentration in clay minerals has a similar effect on the count rate. </p> <div class="mw-heading mw-heading4"><h4 id="Sonic">Sonic</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=9" title="Edit section: Sonic"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Sonic_logging" title="Sonic logging">Sonic logging</a></div> <p>A sonic log provides a formation interval transit time, which is typically a function of lithology and rock texture but particularly porosity. The logging tool consists of at least one piezoelectric transmitter and two or more receivers. The time it takes for the sound wave to travel the fixed distance between two receivers is recorded as an <i>interval transit time</i>. </p> <div class="mw-heading mw-heading3"><h3 id="Lithology_logs">Lithology logs</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=10" title="Edit section: Lithology logs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Gamma_ray">Gamma ray</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=11" title="Edit section: Gamma ray"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Gamma_ray_logging" title="Gamma ray logging">Gamma ray logging</a></div> <p>A log of the natural radioactivity of the formation along the borehole, measured in <a href="/wiki/American_Petroleum_Institute#Standards_and_certification" title="American Petroleum Institute">API units</a>, particularly useful for distinguishing between sands and shales in a siliclastic environment.<sup id="cite_ref-darling_15-0" class="reference"><a href="#cite_note-darling-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> This is because sandstones are usually nonradioactive quartz, whereas shales are naturally radioactive due to potassium isotopes in clays, and adsorbed uranium and thorium. </p><p>In some rocks, and in particular in carbonate rocks, the contribution from uranium can be large and erratic, and can cause the carbonate to be mistaken for a shale. In this case, the carbonate gamma ray is a better indicator of shale content. The carbonate gamma ray log is a gamma ray log from which the uranium contribution has been subtracted. </p> <div class="mw-heading mw-heading4"><h4 id="Self/spontaneous_potential"><span id="Self.2Fspontaneous_potential"></span>Self/spontaneous potential</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=12" title="Edit section: Self/spontaneous potential"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Spontaneous_potential_logging" title="Spontaneous potential logging">Spontaneous potential logging</a></div> <p>The Spontaneous Potential (SP) log measures the natural or <a href="/wiki/Spontaneous_potential" title="Spontaneous potential">spontaneous potential difference</a> between the borehole and the surface, without any applied current. It was one of the first wireline logs to be developed, found when a single potential <a href="/wiki/Electrode" title="Electrode">electrode</a> was lowered into a well and a potential was measured relative to a fixed reference electrode at the surface.<sup id="cite_ref-Etnyre_16-0" class="reference"><a href="#cite_note-Etnyre-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> </p><p>The most useful component of this potential difference is the <a href="/wiki/Electrochemical_potential" title="Electrochemical potential">electrochemical potential</a> because it can cause a significant deflection in the SP response opposite permeable beds. The magnitude of this deflection depends mainly on the <a href="/wiki/Salinity" title="Salinity">salinity</a> contrast between the drilling mud and the formation water, and the clay content of the permeable bed. Therefore, the SP log is commonly used to detect permeable beds and to estimate clay content and formation water salinity. The SP log can be used to distinguish between impermeable shale and permeable shale and porous sands. </p> <div class="mw-heading mw-heading3"><h3 id="Miscellaneous_logs">Miscellaneous logs</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=13" title="Edit section: Miscellaneous logs"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <div class="mw-heading mw-heading4"><h4 id="Caliper">Caliper</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=14" title="Edit section: Caliper"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Caliper_log" title="Caliper log">Caliper log</a></div> <p>A tool that measures the diameter of the borehole mechanically, using either 2 or 4 arms,<sup id="cite_ref-darling_15-1" class="reference"><a href="#cite_note-darling-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> or through high-frequency acoustic signals.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> Because most logs are dependent on borehole regularity to record accurately, the caliper log can indicate where logs are potentially compromised due to the borehole being either over-gauged (due to washout) or under-gauged (like mudcake buildup). </p> <div class="mw-heading mw-heading4"><h4 id="Nuclear_magnetic_resonance">Nuclear magnetic resonance</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=15" title="Edit section: Nuclear magnetic resonance"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Nuclear_magnetic_resonance_logging" title="Nuclear magnetic resonance logging">Nuclear magnetic resonance logging</a></div> <p>Nuclear magnetic resonance (NMR) logging uses the <a href="/wiki/Nuclear_magnetic_resonance" title="Nuclear magnetic resonance">NMR response</a> of a <a href="/wiki/Formation_(stratigraphy)" class="mw-redirect" title="Formation (stratigraphy)">formation</a> to directly determine its <a href="/wiki/Porosity" title="Porosity">porosity</a> and <a href="/wiki/Permeability_(earth_sciences)" class="mw-redirect" title="Permeability (earth sciences)">permeability</a>, providing a continuous record along the length of the <a href="/wiki/Borehole" title="Borehole">borehole</a>.<sup id="cite_ref-18" class="reference"><a href="#cite_note-18"><span class="cite-bracket">[</span>18<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-Kleinberg_19-0" class="reference"><a href="#cite_note-Kleinberg-19"><span class="cite-bracket">[</span>19<span class="cite-bracket">]</span></a></sup> The chief application of the NMR tool is to determine moveable fluid volume (BVM) of a rock. This is the pore space excluding clay bound water (CBW) and irreducible water (BVI). Neither of these are moveable in the NMR sense, so these volumes are not easily observed on older logs. On modern tools, both CBW and BVI can often be seen in the signal response after transforming the relaxation curve to the porosity domain. Note that some of the moveable fluids (BVM) in the NMR sense are not actually moveable in the oilfield sense of the word. Residual oil and gas, heavy oil, and bitumen may appear moveable to the NMR precession measurement, but these will not necessarily flow into a well bore.<sup id="cite_ref-20" class="reference"><a href="#cite_note-20"><span class="cite-bracket">[</span>20<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Spectral_acoustic_logging">Spectral acoustic logging</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=16" title="Edit section: Spectral acoustic logging"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Spectral acoustic logging is an acoustic measurement technique used in <a href="/wiki/Oil_well" title="Oil well">oil</a> and <a href="/wiki/Gas_well" class="mw-redirect" title="Gas well">gas wells</a> for well integrity analysis, identification of production and injection intervals and hydrodynamic characterisation of the reservoir. Spectral acoustic logging records acoustic energy generated by fluid or gas flow through the reservoir or leaks in downhole well components. </p><p>Acoustic logging tools have been used in the <a href="/wiki/Petroleum_industry" title="Petroleum industry">petroleum industry</a> for several decades. As far back as 1955, an acoustic detector was proposed for use in well integrity analysis to identify casing holes.<sup id="cite_ref-21" class="reference"><a href="#cite_note-21"><span class="cite-bracket">[</span>21<span class="cite-bracket">]</span></a></sup> Over many years, downhole acoustic logging tools proved effective in inflow and injectivity profiling of operating wells,<sup id="cite_ref-22" class="reference"><a href="#cite_note-22"><span class="cite-bracket">[</span>22<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-23" class="reference"><a href="#cite_note-23"><span class="cite-bracket">[</span>23<span class="cite-bracket">]</span></a></sup> leak detection,<sup id="cite_ref-24" class="reference"><a href="#cite_note-24"><span class="cite-bracket">[</span>24<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-25" class="reference"><a href="#cite_note-25"><span class="cite-bracket">[</span>25<span class="cite-bracket">]</span></a></sup> location of cross-flows behind casing,<sup id="cite_ref-26" class="reference"><a href="#cite_note-26"><span class="cite-bracket">[</span>26<span class="cite-bracket">]</span></a></sup> and even in determining reservoir <a href="/wiki/Fluid" title="Fluid">fluid</a> compositions.<sup id="cite_ref-27" class="reference"><a href="#cite_note-27"><span class="cite-bracket">[</span>27<span class="cite-bracket">]</span></a></sup> Robinson (1974) described how noise logging can be used to determine effective reservoir thickness.<sup id="cite_ref-28" class="reference"><a href="#cite_note-28"><span class="cite-bracket">[</span>28<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading4"><h4 id="Corrosion_well_logging">Corrosion well logging</h4><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=17" title="Edit section: Corrosion well logging"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Throughout the life of the wells, integrity controles of the steel and cemented column (casing and tubing) are performed using calipers and thickness gauges. These advanced technical methods use non destructive technologies as ultrasonic, electromagnetic and magnetic transducers.<sup id="cite_ref-29" class="reference"><a href="#cite_note-29"><span class="cite-bracket">[</span>29<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Logging_while_drilling">Logging while drilling</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=18" title="Edit section: Logging while drilling"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Logging_while_drilling" title="Logging while drilling">Logging while drilling</a></div> <p>In the 1970s, a new approach to wireline logging was introduced in the form of <a href="/wiki/Logging_While_Drilling" class="mw-redirect" title="Logging While Drilling">logging while drilling (LWD)</a>. This technique provides similar well information to conventional wireline logging but instead of sensors being lowered into the well at the end of wireline cable, the sensors are integrated into the <a href="/wiki/Drill_string" title="Drill string">drill string</a> and the measurements are made in real-time, whilst the well is being drilled. This allows drilling engineers and geologists to quickly obtain information such as porosity, resistivity, hole direction and weight-on-bit and they can use this information to make immediate decisions about the future of the well and the direction of drilling.<sup id="cite_ref-30" class="reference"><a href="#cite_note-30"><span class="cite-bracket">[</span>30<span class="cite-bracket">]</span></a></sup> </p><p>In LWD, measured data is transmitted to the surface in real time via pressure pulses in the well's mud fluid column. This mud telemetry method provides a bandwidth of less than 10 bits per second, although, as drilling through rock is a fairly slow process, data compression techniques mean that this is an ample bandwidth for real-time delivery of information. A higher sample rate of data is recorded into memory and retrieved when the drillstring is withdrawn at bit changes. High-definition downhole and subsurface information is available through <a href="/wiki/IntelliServ#Technology" title="IntelliServ">networked or wired drillpipe</a> that deliver memory quality data in real time.<sup id="cite_ref-31" class="reference"><a href="#cite_note-31"><span class="cite-bracket">[</span>31<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Memory_log">Memory log</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=19" title="Edit section: Memory log"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>This method of data acquisition involves recording the sensor data into a down hole memory, rather than transmitting "Real Time" to surface. There are some advantages and disadvantages to this memory option. </p> <ul><li>The tools can be conveyed into wells where the trajectory is deviated or extended beyond the reach of conventional Electric Wireline cables. This can involve a combination of weight to strength ratio of the electric cable over this extended reach. In such cases the memory tools can be conveyed on Pipe or Coil Tubing.</li> <li>The type of sensors are limited in comparison to those used on Electric Line, and tend to be focussed on the cased hole, production stage of the well. Although there are now developed some memory "Open Hole" compact formation evaluation tool combinations. These tools can be deployed and carried downhole concealed internally in drill pipe to protect them from damage while running in the hole, and then "Pumped" out the end at depth to initiate logging. Other basic open hole formation evaluation memory tools are available for use in "Commodity" markets on slickline to reduce costs and operating time.</li> <li>In cased hole operation there is normally a "Slick Line" intervention unit. This uses a solid mechanical wire (0.072 - 0.125 inches in OD), to manipulate or otherwise carry out operations in the well bore completion system. Memory operations are often carried out on this Slickline conveyance in preference to mobilizing a full service Electric Wireline unit.</li> <li>Since the results are not known until returned to surface, any realtime well dynamic changes cannot be monitored real time. This limits the ability to modify or change the well down hole production conditions accurately during the memory logging by changing the surface production rates. Something that is often done in Electric Line operations.</li> <li>Failure during recording is not known until the memory tools are retrieved. This loss of data can be a major issue on large offshore (expensive) locations. On land locations (e.g. South Texas, US) where there is what is called a "Commodity" Oil service sector, where logging often is without the rig infrastructure. this is less problematic, and logs are often run again without issue.</li></ul> <div class="mw-heading mw-heading2"><h2 id="Coring">Coring</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=20" title="Edit section: Coring"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Core_sample" title="Core sample">Core sample</a></div> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:Rochovce_granite01.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9a/Rochovce_granite01.JPG/220px-Rochovce_granite01.JPG" decoding="async" width="220" height="165" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9a/Rochovce_granite01.JPG/330px-Rochovce_granite01.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9a/Rochovce_granite01.JPG/440px-Rochovce_granite01.JPG 2x" data-file-width="1777" data-file-height="1333" /></a><figcaption>An example of a granite core</figcaption></figure> <p>Coring is the process of obtaining an actual sample of a rock formation from the borehole. There are two main types of coring: 'full coring', in which a sample of rock is obtained using a specialised drill-bit as the borehole is first penetrating the formation and 'sidewall coring', in which multiple samples are obtained from the side of the borehole after it has penetrated through a formation. The main advantage of sidewall coring over full coring are that it is cheaper (drilling doesn't have to be stopped) and multiple samples can be easily acquired, with the main disadvantages being that there can be uncertainty in the depth at which the sample was acquired and the tool can fail to acquire the sample.<sup id="cite_ref-32" class="reference"><a href="#cite_note-32"><span class="cite-bracket">[</span>32<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-33" class="reference"><a href="#cite_note-33"><span class="cite-bracket">[</span>33<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading2"><h2 id="Mudlogging">Mudlogging</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=21" title="Edit section: Mudlogging"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Mud_logging" title="Mud logging">Mud logging</a></div> <p><i><a href="/wiki/Mud_log" class="mw-redirect" title="Mud log">Mud logs</a></i> are well logs prepared by describing rock or soil cuttings brought to the surface by mud circulating in the borehole. In the oil industry they are usually prepared by a <a href="/wiki/Mud_logging" title="Mud logging">mud logging</a> company contracted by the operating company. One parameter a typical mud log displays is the formation gas (gas units or ppm). "The gas recorder usually is scaled in terms of arbitrary gas units, which are defined differently by the various gas-detector manufactures. In practice, significance is placed only on relative changes in the gas concentrations detected."<sup id="cite_ref-34" class="reference"><a href="#cite_note-34"><span class="cite-bracket">[</span>34<span class="cite-bracket">]</span></a></sup> The current <a href="/wiki/Oil_industry" class="mw-redirect" title="Oil industry">oil industry</a> standard <a href="/wiki/Mud_log" class="mw-redirect" title="Mud log">mud log</a> normally includes real-time drilling parameters such as <a href="/wiki/Rate_of_penetration" title="Rate of penetration">rate of penetration</a> (ROP), <a href="/wiki/Lithology" title="Lithology">lithology</a>, gas <a href="/wiki/Hydrocarbons" class="mw-redirect" title="Hydrocarbons">hydrocarbons</a>, flow line temperature (temperature of the <a href="/wiki/Drilling_fluid" title="Drilling fluid">drilling fluid</a>) and <a href="/wiki/Chloride" title="Chloride">chlorides</a> but may also include <a href="/wiki/Mud_weight" title="Mud weight">mud weight</a>, <a href="/wiki/Estimated_pore_pressure" title="Estimated pore pressure">estimated pore pressure</a> and <a href="/wiki/Corrected_d-exponent" title="Corrected d-exponent">corrected d-exponent</a> (corrected drilling exponent) for a pressure pack log. Other information that is normally notated on a <a href="/wiki/Mud_log" class="mw-redirect" title="Mud log">mud log</a> include directional data (<a href="/wiki/Deviation_surveys" class="mw-redirect" title="Deviation surveys">deviation surveys</a>), <a href="/wiki/Weight_on_bit" title="Weight on bit">weight on bit</a>, <a href="/wiki/Rotary_table_(drilling_rig)" title="Rotary table (drilling rig)">rotary speed</a>, <a href="/w/index.php?title=Pump_pressure&action=edit&redlink=1" class="new" title="Pump pressure (page does not exist)">pump pressure</a>, <a href="/w/index.php?title=Pump_rate&action=edit&redlink=1" class="new" title="Pump rate (page does not exist)">pump rate</a>, <a href="/wiki/Viscosity" title="Viscosity">viscosity</a>, drill bit info, casing shoe depths, formation tops, mud pump info, to name just a few. </p> <div class="mw-heading mw-heading2"><h2 id="Information_use">Information use</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=22" title="Edit section: Information use"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">See also: <a href="/wiki/Formation_evaluation" title="Formation evaluation">Formation evaluation</a></div> <p>In the oil industry, the well and mud logs are usually transferred in 'real time' to the operating company, which uses these logs to make operational decisions about the well, to correlate formation depths with surrounding wells, and to make interpretations about the quantity and quality of hydrocarbons present. Specialists involved in well log interpretation are called log analysts. </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=23" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Drilling_mud" class="mw-redirect" title="Drilling mud">Drilling mud</a></li> <li><a href="/wiki/Drilling_rig" title="Drilling rig">Drilling rig</a></li> <li><a href="/wiki/Erygmascope" title="Erygmascope">Erygmascope</a></li> <li><a href="/wiki/Formation_evaluation" title="Formation evaluation">Formation evaluation</a></li> <li><a href="/wiki/Well_control" title="Well control">Well control</a></li> <li><a href="/wiki/Geosteering" title="Geosteering">Geosteering</a></li> <li><a href="/wiki/List_of_oilfield_service_companies" title="List of oilfield service companies">List of oilfield service companies</a></li> <li><a href="/wiki/Log_ASCII_Standard" class="mw-redirect" title="Log ASCII Standard">Log ASCII Standard</a> (LAS)</li> <li><a href="/wiki/Wireline_(cabling)" title="Wireline (cabling)">Wireline</a></li> <li><a href="/wiki/List_of_abbreviations_in_oil_and_gas_exploration_and_production" title="List of abbreviations in oil and gas exploration and production">List of abbreviations in oil and gas exploration and production</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=24" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://deltaepsilon.com/groundwater-logging/">"Groundwater Logging"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Groundwater+Logging&rft_id=https%3A%2F%2Fdeltaepsilon.com%2Fgroundwater-logging%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text">Harald Bolt, Wireline Depth Determination, Rev 3.3, Apr 2012, available via Society of Professional Well Log Analysts web site, www.spwla.org</span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSociety_of_Professional_Well_Log_Analysts1975" class="citation book cs1"><a href="/w/index.php?title=Society_of_Petrophysicists_and_Well_Log_Analysts&action=edit&redlink=1" class="new" title="Society of Petrophysicists and Well Log Analysts (page does not exist)">Society of Professional Well Log Analysts</a> (1975). <i>Glossary of terms & expressions used in well logging</i>. Houston, Texas: SPWLA. p. 74 p.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Glossary+of+terms+%26+expressions+used+in+well+logging&rft.place=Houston%2C+Texas&rft.pages=74+p&rft.pub=SPWLA&rft.date=1975&rft.au=Society+of+Professional+Well+Log+Analysts&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHilchie1990" class="citation book cs1">Hilchie, Douglas W. (1990). <i>Wireline: A history of the well logging and perforating business in the oil fields</i>. Boulder, Colorado: Privately Published. p. 200.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Wireline%3A+A+history+of+the+well+logging+and+perforating+business+in+the+oil+fields&rft.place=Boulder%2C+Colorado&rft.pages=200&rft.pub=Privately+Published&rft.date=1990&rft.aulast=Hilchie&rft.aufirst=Douglas+W.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPikeRhonda_Duey2002" class="citation journal cs1">Pike, Bill; Rhonda Duey (2002). <a rel="nofollow" class="external text" href="http://www.accessmylibrary.com/coms2/summary_0286-7442038_ITM">"Logging history rich with innovation"</a>. <i>Hart's E&P</i>: 52–55<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-06-02</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Hart%27s+E%26P&rft.atitle=Logging+history+rich+with+innovation&rft.pages=52-55&rft.date=2002&rft.aulast=Pike&rft.aufirst=Bill&rft.au=Rhonda+Duey&rft_id=http%3A%2F%2Fwww.accessmylibrary.com%2Fcoms2%2Fsummary_0286-7442038_ITM&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged June 2016">dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text">Now a division of Baker Hughes</span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKleinberg2001" class="citation journal cs1">Kleinberg, Robert L. (2001). <a rel="nofollow" class="external text" href="https://www.researchgate.net/publication/229709476">"NMR well logging at Schlumberger"</a>. <i>Concepts in Magnetic Resonance</i>. <b>13</b> (6): 396–403. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fcmr.1026">10.1002/cmr.1026</a><span class="reference-accessdate">. Retrieved <span class="nowrap">23 September</span> 2020</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Concepts+in+Magnetic+Resonance&rft.atitle=NMR+well+logging+at+Schlumberger&rft.volume=13&rft.issue=6&rft.pages=396-403&rft.date=2001&rft_id=info%3Adoi%2F10.1002%2Fcmr.1026&rft.aulast=Kleinberg&rft.aufirst=Robert+L.&rft_id=https%3A%2F%2Fwww.researchgate.net%2Fpublication%2F229709476&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBloembergen1966" class="citation journal cs1">Bloembergen, N. (1966). "Paramagnetic resonance precision method and apparatus for well logging". <i>U.S. Patent 3,242,422</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=U.S.+Patent+3%2C242%2C422&rft.atitle=Paramagnetic+resonance+precision+method+and+apparatus+for+well+logging&rft.date=1966&rft.aulast=Bloembergen&rft.aufirst=N.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFKleinbergJackson2001" class="citation journal cs1">Kleinberg, Robert L.; Jackson, Jasper A. (2001). <a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fcmr.1018">"An introduction to the history of NMR well logging"</a>. <i>Concepts in Magnetic Resonance</i>. <b>13</b> (6): 340–342. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1002%2Fcmr.1018">10.1002/cmr.1018</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Concepts+in+Magnetic+Resonance&rft.atitle=An+introduction+to+the+history+of+NMR+well+logging&rft.volume=13&rft.issue=6&rft.pages=340-342&rft.date=2001&rft_id=info%3Adoi%2F10.1002%2Fcmr.1018&rft.aulast=Kleinberg&rft.aufirst=Robert+L.&rft.au=Jackson%2C+Jasper+A.&rft_id=https%3A%2F%2Fdoi.org%2F10.1002%252Fcmr.1018&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">Taherdangkoo, R., & Abdideh, M. (2016). Application of wavelet transform to detect fractured zones using conventional well logs data (Case study: Southwest of Iran). International Journal of Petroleum Engineering, 2(2), 125-139.</span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://petrowiki.org/Borehole_imaging">"Borehole imaging"</a>. 2 July 2015.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Borehole+imaging&rft.date=2015-07-02&rft_id=http%3A%2F%2Fpetrowiki.org%2FBorehole_imaging&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSengel1981" class="citation book cs1">Sengel, E.W. "Bill" (1981). <i>Handbook on well logging</i>. Oklahoma City, Oklahoma: Institute for Energy Development. p. 168 p. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-89419-112-8" title="Special:BookSources/0-89419-112-8"><bdi>0-89419-112-8</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Handbook+on+well+logging&rft.place=Oklahoma+City%2C+Oklahoma&rft.pages=168+p&rft.pub=Institute+for+Energy+Development&rft.date=1981&rft.isbn=0-89419-112-8&rft.aulast=Sengel&rft.aufirst=E.W.+%22Bill%22&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.glossary.oilfield.slb.com/Display.cfm?Term=epithermal%20neutron%20porosity%20measurement">"Schlumberger Oilfield Glossary"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Schlumberger+Oilfield+Glossary&rft_id=http%3A%2F%2Fwww.glossary.oilfield.slb.com%2FDisplay.cfm%3FTerm%3Depithermal%2520neutron%2520porosity%2520measurement&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFEtnyre1989" class="citation book cs1">Etnyre, L.M. (1989). <i>Finding Oil and Gas from Well Logs</i>. Kluwer Academic Publishers. p. 249 p. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0442223090" title="Special:BookSources/978-0442223090"><bdi>978-0442223090</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Finding+Oil+and+Gas+from+Well+Logs&rft.pages=249+p&rft.pub=Kluwer+Academic+Publishers&rft.date=1989&rft.isbn=978-0442223090&rft.aulast=Etnyre&rft.aufirst=L.M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-darling-15"><span class="mw-cite-backlink">^ <a href="#cite_ref-darling_15-0"><sup><i><b>a</b></i></sup></a> <a href="#cite_ref-darling_15-1"><sup><i><b>b</b></i></sup></a></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDarling2005" class="citation book cs1">Darling, Toby (2005). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=vKdIGNAE8JYC"><i>Well Logging and Formation Evaluation</i></a>. Oxford, UK: Elsevier. p. 5 p. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-7506-7883-6" title="Special:BookSources/0-7506-7883-6"><bdi>0-7506-7883-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Well+Logging+and+Formation+Evaluation&rft.place=Oxford%2C+UK&rft.pages=5+p&rft.pub=Elsevier&rft.date=2005&rft.isbn=0-7506-7883-6&rft.aulast=Darling&rft.aufirst=Toby&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DvKdIGNAE8JYC&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-Etnyre-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-Etnyre_16-0">^</a></b></span> <span class="reference-text"> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFEtnyre1989" class="citation book cs1">Etnyre, L.M. (1989). <i>Finding Oil and Gas from Well Logs</i>. Kluwer Academic Publishers. p. 220 p. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0442223090" title="Special:BookSources/978-0442223090"><bdi>978-0442223090</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Finding+Oil+and+Gas+from+Well+Logs&rft.pages=220+p&rft.pub=Kluwer+Academic+Publishers&rft.date=1989&rft.isbn=978-0442223090&rft.aulast=Etnyre&rft.aufirst=L.M.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://glossary.slb.com/en/terms/u/ultrasonic_caliper">"ultrasonic caliper"</a>. <i>Schlumberger Energy Glossary</i>. Schlumberger.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=Schlumberger+Energy+Glossary&rft.atitle=ultrasonic+caliper&rft_id=https%3A%2F%2Fglossary.slb.com%2Fen%2Fterms%2Fu%2Fultrasonic_caliper&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-18"><span class="mw-cite-backlink"><b><a href="#cite_ref-18">^</a></b></span> <span class="reference-text">Gluyas, J. & Swarbrick, R. (2004) Petroleum Geoscience. Publ. Blackwell Publishing</span> </li> <li id="cite_note-Kleinberg-19"><span class="mw-cite-backlink"><b><a href="#cite_ref-Kleinberg_19-0">^</a></b></span> <span class="reference-text">Nuclear Magnetic Resonance Imaging – Technology of the 21st century. Kenyon, Kleinberg, Straley, Gubelin, and Morris. Oilfield Review. <a rel="nofollow" class="external free" href="http://eps.mcgill.ca/~courses/c550/Literature/NMR-21st-century.pdf">http://eps.mcgill.ca/~courses/c550/Literature/NMR-21st-century.pdf</a><sup class="noprint Inline-Template"><span style="white-space: nowrap;">[<i><a href="/wiki/Wikipedia:Link_rot" title="Wikipedia:Link rot"><span title=" Dead link tagged September 2017">permanent dead link</span></a></i><span style="visibility:hidden; color:transparent; padding-left:2px">‍</span>]</span></sup></span> </li> <li id="cite_note-20"><span class="mw-cite-backlink"><b><a href="#cite_ref-20">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.spec2000.net/07-nmrlog.htm">"Crain's Petrophysical Handbook | Login Page"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Crain%27s+Petrophysical+Handbook+%26%23124%3B+Login+Page&rft_id=https%3A%2F%2Fwww.spec2000.net%2F07-nmrlog.htm&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-21"><span class="mw-cite-backlink"><b><a href="#cite_ref-21">^</a></b></span> <span class="reference-text">Enright, R.J. 1955. Sleuth for Down-Hole Leaks, Oil & Gas J.:78-79</span> </li> <li id="cite_note-22"><span class="mw-cite-backlink"><b><a href="#cite_ref-22">^</a></b></span> <span class="reference-text">Britt E.L. 1976. Theory and applications of the borehole audio tracer survey, the SPWLA Seventeenth Annual Logging Symposium, Denver, Colorado</span> </li> <li id="cite_note-23"><span class="mw-cite-backlink"><b><a href="#cite_ref-23">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-162081-MS">Spectral Noise Logging Data Processing Technology</a></span> </li> <li id="cite_note-24"><span class="mw-cite-backlink"><b><a href="#cite_ref-24">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-161983-MS">Leak Detection by Temperature and Noise Logging</a></span> </li> <li id="cite_note-25"><span class="mw-cite-backlink"><b><a href="#cite_ref-25">^</a></b></span> <span class="reference-text"><a rel="nofollow" class="external text" href="http://www.onepetro.org/mslib/servlet/onepetropreview?id=SPE-161712-MS">Innovative Logging Tool Using Noise Log and High Precision Temperature Help to Diagnoses Complex Problems</a></span> </li> <li id="cite_note-26"><span class="mw-cite-backlink"><b><a href="#cite_ref-26">^</a></b></span> <span class="reference-text">McKinley, R.M. 1994. Temperature, Radioactive Tracer, and Noise Logging for Well Integrity: 112-156</span> </li> <li id="cite_note-27"><span class="mw-cite-backlink"><b><a href="#cite_ref-27">^</a></b></span> <span class="reference-text">Wang J, Alex van der Spek et al. 1999. Characterizing Sound Generated by Multiphase Flow, SPE Annual Technical Conference and Exhibition held in Houston, Texas</span> </li> <li id="cite_note-28"><span class="mw-cite-backlink"><b><a href="#cite_ref-28">^</a></b></span> <span class="reference-text">Robinson W.S. 1974. Field Results From the Noise-Logging Technique, 49th Annual Fall Meeting of the SPE of AIME in Houston, Texas</span> </li> <li id="cite_note-29"><span class="mw-cite-backlink"><b><a href="#cite_ref-29">^</a></b></span> <span class="reference-text">Stéphane Sainson, <i>Les diagraphies de corrosion</i>. Ed. Lavoisier, 548 p., 2010</span> </li> <li id="cite_note-30"><span class="mw-cite-backlink"><b><a href="#cite_ref-30">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.rigzone.com/training/insight?insight_id=297&c_id=1">"How Does Logging-While-Drilling (LWD) Work?"</a>. <i>www.rigzone.com</i>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.rigzone.com&rft.atitle=How+Does+Logging-While-Drilling+%28LWD%29+Work%3F&rft_id=https%3A%2F%2Fwww.rigzone.com%2Ftraining%2Finsight%3Finsight_id%3D297%26c_id%3D1&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-31"><span class="mw-cite-backlink"><b><a href="#cite_ref-31">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFAliM._SasJ.H._HoodS.R._Lemke2008" class="citation journal cs1">Ali, T.H.; M. Sas; J.H. Hood; S.R. Lemke; A. Srinivasan (2008). <a rel="nofollow" class="external text" href="http://www.onepetro.org/mslib/app/Preview.do?paperNumber=SPE-112636-MS&societyCode=SPE">"High Speed Telemetry Drill Pipe Network Optimizes Drilling Dynamics And Wellbore Placement"</a>. <i>Society of Petroleum Engineers</i><span class="reference-accessdate">. Retrieved <span class="nowrap">25 September</span> 2012</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Society+of+Petroleum+Engineers&rft.atitle=High+Speed+Telemetry+Drill+Pipe+Network+Optimizes+Drilling+Dynamics+And+Wellbore+Placement&rft.date=2008&rft.aulast=Ali&rft.aufirst=T.H.&rft.au=M.+Sas&rft.au=J.H.+Hood&rft.au=S.R.+Lemke&rft.au=A.+Srinivasan&rft_id=http%3A%2F%2Fwww.onepetro.org%2Fmslib%2Fapp%2FPreview.do%3FpaperNumber%3DSPE-112636-MS%26societyCode%3DSPE&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-32"><span class="mw-cite-backlink"><b><a href="#cite_ref-32">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20111011073101/http://www.halliburton.com/ps/default.aspx?navid=1831&pageid=1141&prodgrpid=PRG%3a%3aJCFUH1E8Z">"Halliburton. Sidewall Coring"</a>. Archived from <a rel="nofollow" class="external text" href="http://www.halliburton.com/ps/default.aspx?navid=1831&pageid=1141&prodgrpid=PRG%3a%3aJCFUH1E8Z">the original</a> on October 11, 2011.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Halliburton.+Sidewall+Coring&rft_id=http%3A%2F%2Fwww.halliburton.com%2Fps%2Fdefault.aspx%3Fnavid%3D1831%26pageid%3D1141%26prodgrpid%3DPRG%253a%253aJCFUH1E8Z&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-33"><span class="mw-cite-backlink"><b><a href="#cite_ref-33">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="http://www.glossary.oilfield.slb.com/Display.cfm?Term=core">"Schlumberger Oilfield Glossary. Core"</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=Schlumberger+Oilfield+Glossary.+Core&rft_id=http%3A%2F%2Fwww.glossary.oilfield.slb.com%2FDisplay.cfm%3FTerm%3Dcore&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> <li id="cite_note-34"><span class="mw-cite-backlink"><b><a href="#cite_ref-34">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBourgoyneMillheimChenevertYoung_Jr.1986" class="citation book cs1">Bourgoyne, Adam; Millheim, Keith; Chenevert, Martin; Young Jr., F.S. (1986). <span class="id-lock-limited" title="Free access subject to limited trial, subscription normally required"><a rel="nofollow" class="external text" href="https://archive.org/details/applieddrillinge00bour"><i>Applied Drilling Engineering</i></a></span>. Richardson, TX: Society of Petroleum Engineers. p. <a rel="nofollow" class="external text" href="https://archive.org/details/applieddrillinge00bour/page/n279">274</a>. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/1-55563-001-4" title="Special:BookSources/1-55563-001-4"><bdi>1-55563-001-4</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Applied+Drilling+Engineering&rft.place=Richardson%2C+TX&rft.pages=274&rft.pub=Society+of+Petroleum+Engineers&rft.date=1986&rft.isbn=1-55563-001-4&rft.aulast=Bourgoyne&rft.aufirst=Adam&rft.au=Millheim%2C+Keith&rft.au=Chenevert%2C+Martin&rft.au=Young+Jr.%2C+F.S.&rft_id=https%3A%2F%2Farchive.org%2Fdetails%2Fapplieddrillinge00bour&rfr_id=info%3Asid%2Fen.wikipedia.org%3AWell+logging" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Well_logging&action=edit&section=25" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="http://www.spwla.org">Society of Petrophysicists & Well Log Analysts</a></li> <li><a rel="nofollow" class="external text" href="https://www.spwla.org/SPWLA/Publications/SPWLA_Today_Newsletter/Recent_SPWLA_Today_Newsletters/Recent_SPWLA_Today_Newsletters">SPWLA Today Newsletter</a></li> <li><a rel="nofollow" class="external text" href="https://www.spwla.org/SPWLA/Publications/Petrophysics_Journal/SPWLA/Publications/Journals/Recent_Petrophysics_Journals.aspx?hkey=f90fbb88-0a09-4236-82cb-6630d0586060">Petrophysics Journal</a></li> <li><a rel="nofollow" class="external text" href="http://jwitsml.org/logio.html">Log I/O</a> Java/.Net library for accessing files of common log formats like LAS, LIS, DLIS, CSV etc.</li></ul> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output .navbox-list-with-group{text-align:left;border-left-width:2px;border-left-style:solid}.mw-parser-output tr+tr>.navbox-abovebelow,.mw-parser-output tr+tr>.navbox-group,.mw-parser-output tr+tr>.navbox-image,.mw-parser-output tr+tr>.navbox-list{border-top:2px solid #fdfdfd}.mw-parser-output .navbox-title{background-color:#ccf}.mw-parser-output .navbox-abovebelow,.mw-parser-output .navbox-group,.mw-parser-output .navbox-subgroup .navbox-title{background-color:#ddf}.mw-parser-output .navbox-subgroup .navbox-group,.mw-parser-output .navbox-subgroup .navbox-abovebelow{background-color:#e6e6ff}.mw-parser-output .navbox-even{background-color:#f7f7f7}.mw-parser-output .navbox-odd{background-color:transparent}.mw-parser-output .navbox .hlist td dl,.mw-parser-output .navbox .hlist td ol,.mw-parser-output .navbox .hlist td ul,.mw-parser-output .navbox td.hlist dl,.mw-parser-output .navbox td.hlist ol,.mw-parser-output .navbox td.hlist ul{padding:0.125em 0}.mw-parser-output .navbox .navbar{display:block;font-size:100%}.mw-parser-output .navbox-title .navbar{float:left;text-align:left;margin-right:0.5em}body.skin--responsive .mw-parser-output .navbox-image img{max-width:none!important}@media print{body.ns-0 .mw-parser-output .navbox{display:none!important}}</style></div><div role="navigation" class="navbox" aria-labelledby="Petroleum_industry" style="padding:3px"><table class="nowraplinks hlist mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Petroleum_industry" title="Template:Petroleum industry"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Petroleum_industry" title="Template talk:Petroleum industry"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Petroleum_industry" title="Special:EditPage/Template:Petroleum industry"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Petroleum_industry" style="font-size:114%;margin:0 4em"><a href="/wiki/Petroleum_industry" title="Petroleum industry">Petroleum industry</a></div></th></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><a href="/wiki/Petroleum" title="Petroleum">Petroleum</a></li> <li><a href="/wiki/Primary_energy" title="Primary energy">Primary energy</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><a href="/wiki/Benchmark_(crude_oil)" title="Benchmark (crude oil)">Benchmarks</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Argus_Sour_Crude_Index" title="Argus Sour Crude Index">Argus Sour</a></li> <li><a href="/wiki/Bonny_Light_oil" title="Bonny Light oil">Bonny Light</a></li> <li><a href="/wiki/Brent_Crude" title="Brent Crude">Brent</a></li> <li><a href="/wiki/Dubai_Crude" title="Dubai Crude">Dubai</a></li> <li><a href="/wiki/Indian_Basket" title="Indian Basket">Indian Basket</a></li> <li><a href="/wiki/Indonesian_Crude_Price" title="Indonesian Crude Price">Indonesian</a></li> <li><a href="/wiki/Isthmus-34_Light" title="Isthmus-34 Light">Isthmus-34 Light</a></li> <li><a href="/wiki/Japan_Crude_Cocktail" title="Japan Crude Cocktail">Japan Cocktail</a></li> <li><a href="/wiki/OPEC_Reference_Basket" title="OPEC Reference Basket">OPEC Reference Basket</a></li> <li><a href="/wiki/Tapis_crude" title="Tapis crude">Tapis</a></li> <li><a href="/wiki/Urals_oil" title="Urals oil">Urals</a></li> <li><a href="/wiki/West_Texas_Intermediate" title="West Texas Intermediate">West Texas Intermediate</a></li> <li><a href="/wiki/Western_Canadian_Select" title="Western Canadian Select">Western Canadian Select</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;">Data</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;">Natural gas</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_countries_by_natural_gas_consumption" title="List of countries by natural gas consumption">Consumption</a></li> <li><a href="/wiki/List_of_countries_by_natural_gas_production" title="List of countries by natural gas production">Production</a></li> <li><a href="/wiki/List_of_countries_by_natural_gas_proven_reserves" title="List of countries by natural gas proven reserves">Reserves</a></li> <li><a href="/wiki/List_of_countries_by_natural_gas_imports" title="List of countries by natural gas imports">Imports</a></li> <li><a href="/wiki/List_of_countries_by_natural_gas_exports" title="List of countries by natural gas exports">Exports</a></li> <li><a href="/wiki/Natural_gas_prices" title="Natural gas prices">Price</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;">Petroleum</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_countries_by_oil_consumption" title="List of countries by oil consumption">Consumption</a></li> <li><a href="/wiki/List_of_countries_by_oil_production" title="List of countries by oil production">Production</a></li> <li><a href="/wiki/List_of_countries_by_proven_oil_reserves" title="List of countries by proven oil reserves">Reserves</a></li> <li><a href="/wiki/List_of_countries_by_oil_imports" title="List of countries by oil imports">Imports</a></li> <li><a href="/wiki/List_of_countries_by_oil_exports" title="List of countries by oil exports">Exports</a></li> <li><a href="/wiki/Posted_oil_price" title="Posted oil price">Posted oil price</a></li> <li><a href="/wiki/Price_of_oil" title="Price of oil">Price</a> <ul><li><a href="/wiki/Gasoline_and_diesel_usage_and_pricing" title="Gasoline and diesel usage and pricing">of gasoline and diesel</a></li></ul></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><a href="/wiki/Hydrocarbon_exploration" title="Hydrocarbon exploration">Exploration</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Core_sample" title="Core sample">Core sampling</a></li> <li><a href="/wiki/Exploration_geophysics" title="Exploration geophysics">Geophysics</a></li> <li><a href="/wiki/Integrated_asset_modelling" title="Integrated asset modelling">Integrated asset modelling</a></li> <li><a href="/wiki/Petroleum_engineering" title="Petroleum engineering">Petroleum engineering</a> <ul><li><a href="/wiki/Reservoir_simulation" title="Reservoir simulation">Reservoir simulation</a></li> <li><a href="/wiki/Reservoir_modeling" title="Reservoir modeling">Reservoir modeling</a></li></ul></li> <li><a href="/wiki/Petroleum_geology" title="Petroleum geology">Petroleum geology</a></li> <li><a href="/wiki/Petrophysics" title="Petrophysics">Petrophysics</a></li> <li><a href="/wiki/Reflection_seismology" title="Reflection seismology">Reflection seismology</a> <ul><li><a href="/wiki/Seismic_inversion" title="Seismic inversion">Seismic inversion</a></li></ul></li> <li><a href="/wiki/Seismic_source" title="Seismic source">Seismic source</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><a href="/wiki/Oil_well" title="Oil well">Drilling</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Blowout_(well_drilling)" title="Blowout (well drilling)">Blowout</a></li> <li><a href="/wiki/Completion_(oil_and_gas_wells)" title="Completion (oil and gas wells)">Completion</a> <ul><li><a href="/wiki/Squeeze_job" title="Squeeze job">Squeeze job</a></li></ul></li> <li><a href="/wiki/Differential_sticking" title="Differential sticking">Differential sticking</a></li> <li><a href="/wiki/Directional_drilling" title="Directional drilling">Directional drilling</a> <ul><li><a href="/wiki/Geosteering" title="Geosteering">Geosteering</a></li></ul></li> <li><a href="/wiki/Drill_stem_test" title="Drill stem test">Drill stem test</a></li> <li><a href="/wiki/Drilling_engineering" title="Drilling engineering">Drilling engineering</a></li> <li><a href="/wiki/Drilling_fluid" title="Drilling fluid">Drilling fluid</a> <ul><li><a href="/wiki/Drilling_fluid_invasion" title="Drilling fluid invasion">invasion</a></li></ul></li> <li><a href="/wiki/Lost_circulation" title="Lost circulation">Lost circulation</a></li> <li><a href="/wiki/Measurement_while_drilling" title="Measurement while drilling">Measurement</a></li> <li><a href="/wiki/Shale_oil_extraction" title="Shale oil extraction">Shale oil extraction</a> <ul><li><a href="/wiki/Fredrik_Ljungstr%C3%B6m#Shale_oil_extraction" title="Fredrik Ljungström">Ljungström method</a></li></ul></li> <li><a href="/wiki/Tracer_use_in_the_oil_industry" title="Tracer use in the oil industry">Tracers</a></li> <li><a href="/wiki/Underbalanced_drilling" title="Underbalanced drilling">Underbalanced drilling</a></li> <li><a class="mw-selflink selflink">Well logging</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><a href="/wiki/Extraction_of_petroleum" title="Extraction of petroleum">Production</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Petroleum_fiscal_regime" title="Petroleum fiscal regime">Petroleum fiscal regime</a> <ul><li><a href="/wiki/Petroleum_licensing" title="Petroleum licensing">Concessions</a></li> <li><a href="/wiki/Production_sharing_agreement" title="Production sharing agreement">Production sharing agreements</a></li></ul></li> <li><a href="/wiki/Artificial_lift" title="Artificial lift">Artificial lift</a> <ul><li><a href="/wiki/Gas_lift" title="Gas lift">Gas lift</a></li> <li><a href="/wiki/Pumpjack" title="Pumpjack">Pumpjack</a></li> <li><a href="/wiki/Submersible_pump" title="Submersible pump">Submersible pump (ESP)</a></li></ul></li> <li><a href="/wiki/Downstream_(petroleum_industry)" title="Downstream (petroleum industry)">Downstream</a></li> <li><a href="/wiki/Enhanced_oil_recovery" title="Enhanced oil recovery">Enhanced oil recovery (EOR)</a> <ul><li><a href="/wiki/Gas_reinjection" title="Gas reinjection">Gas reinjection</a></li> <li><a href="/wiki/Steam_injection_(oil_industry)" title="Steam injection (oil industry)">Steam injection</a></li></ul></li> <li><a href="/wiki/Midstream" title="Midstream">Midstream</a></li> <li><a href="/wiki/Petroleum_product" title="Petroleum product">Petroleum product</a></li> <li><a href="/wiki/Pipeline" title="Pipeline">Pipeline</a></li> <li><a href="/wiki/Oil_refinery" title="Oil refinery">Refining</a></li> <li><a href="/wiki/Upstream_(petroleum_industry)" title="Upstream (petroleum industry)">Upstream</a></li> <li><a href="/wiki/Water_injection_(oil_production)" title="Water injection (oil production)">Water injection</a></li> <li><a href="/wiki/Well_intervention" title="Well intervention">Well intervention</a></li> <li><a href="/wiki/Christmas_tree_(oil_well)" title="Christmas tree (oil well)">XT</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><a href="/wiki/History_of_the_petroleum_industry" title="History of the petroleum industry">History</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/1967_Oil_Embargo" title="1967 Oil Embargo">1967 Oil Embargo</a></li> <li><a href="/wiki/1973_oil_crisis" title="1973 oil crisis">1973 oil crisis</a></li> <li><a href="/wiki/1979_oil_crisis" title="1979 oil crisis">1979 oil crisis</a></li> <li><a href="/wiki/1980s_oil_glut" title="1980s oil glut">1980s oil glut</a></li> <li><a href="/wiki/1990_oil_price_shock" title="1990 oil price shock">1990 oil price shock</a></li> <li><a href="/wiki/2000s_energy_crisis" title="2000s energy crisis">2000s energy crisis</a></li> <li><a href="/wiki/2010s_oil_glut" title="2010s oil glut">2010s oil glut</a></li> <li><a href="/wiki/2020_Russia%E2%80%93Saudi_Arabia_oil_price_war" title="2020 Russia–Saudi Arabia oil price war">2020 Russia–Saudi Arabia oil price war</a></li> <li><a href="/wiki/Nationalization_of_oil_supplies" title="Nationalization of oil supplies">Nationalization</a></li> <li><a href="/wiki/Gas_Exporting_Countries_Forum" title="Gas Exporting Countries Forum">GECF</a></li> <li><a href="/wiki/OPEC" title="OPEC">OPEC</a></li> <li><a href="/wiki/Seven_Sisters_(oil_companies)" class="mw-redirect" title="Seven Sisters (oil companies)">Seven Sisters</a></li> <li><a href="/wiki/Standard_Oil" title="Standard Oil">Standard Oil</a></li> <li><a href="/wiki/History_of_the_petroleum_industry_in_Canada" title="History of the petroleum industry in Canada">Canada</a></li> <li><a href="/wiki/History_of_the_petroleum_industry_in_France" title="History of the petroleum industry in France">France</a></li> <li><a href="/wiki/History_of_the_oil_industry_in_India" title="History of the oil industry in India">India</a></li> <li><a href="/wiki/Petroleum_industry_in_Iraq" title="Petroleum industry in Iraq">Iraq</a></li> <li><a href="/wiki/History_of_the_petroleum_industry_in_Norway" title="History of the petroleum industry in Norway">Norway</a></li> <li><a href="/wiki/History_of_the_oil_industry_in_Saudi_Arabia" title="History of the oil industry in Saudi Arabia">Saudi Arabia</a></li> <li><a href="/wiki/History_of_the_petroleum_industry_in_the_United_States" title="History of the petroleum industry in the United States">United States</a></li> <li><a href="/wiki/History_of_the_Venezuelan_oil_industry" title="History of the Venezuelan oil industry">Venezuela</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;">Provinces<br />and fields</th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_natural_gas_fields" title="List of natural gas fields">List of natural gas fields</a></li> <li><a href="/wiki/List_of_oil_fields" title="List of oil fields">List of oil fields</a></li> <li><a href="/wiki/Caspian_Sea" title="Caspian Sea">Caspian Sea</a></li> <li><a href="/wiki/East_Midlands_Oil_Province" title="East Midlands Oil Province">East Midlands Oil Province</a></li> <li><a href="/wiki/East_Texas_Oil_Field" title="East Texas Oil Field">East Texas</a></li> <li><a href="/wiki/Gulf_of_Mexico" title="Gulf of Mexico">Gulf of Mexico</a></li> <li><a href="/wiki/Niger_Delta#Nigerian_oil" title="Niger Delta">Niger Delta</a></li> <li><a href="/wiki/North_Sea_oil" title="North Sea oil">North Sea</a></li> <li><a href="/wiki/Permian_Basin_(North_America)" title="Permian Basin (North America)">Permian Basin</a></li> <li><a href="/wiki/Persian_Gulf" title="Persian Gulf">Persian Gulf</a></li> <li><a href="/wiki/Prudhoe_Bay_Oil_Field" title="Prudhoe Bay Oil Field">Prudhoe Bay</a></li> <li><a href="/wiki/Oil_reserves_in_Russia" title="Oil reserves in Russia">Russia</a></li> <li><a href="/wiki/Oil_reserves_in_Venezuela" title="Oil reserves in Venezuela">Venezuela</a></li> <li><a href="/wiki/Western_Canadian_Sedimentary_Basin" class="mw-redirect" title="Western Canadian Sedimentary Basin">Western Canadian Sedimentary Basin</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;">Other topics</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/List_of_abbreviations_in_oil_and_gas_exploration_and_production" title="List of abbreviations in oil and gas exploration and production">Abbreviations</a></li> <li>Classification <ul><li><a href="/wiki/Sweet_crude_oil" title="Sweet crude oil">sweet oil</a></li> <li><a href="/wiki/Sour_crude_oil" title="Sour crude oil">sour oil</a></li></ul></li> <li><a href="/wiki/Oil_shale_gas" title="Oil shale gas">Oil shale gas</a></li> <li><a href="/wiki/Orphan_wells" title="Orphan wells">Orphan wells</a></li> <li><a href="/wiki/Peak_oil" title="Peak oil">Peak oil</a> <ul><li><a href="/wiki/Fossil_fuel_phase-out" title="Fossil fuel phase-out">fossil fuel phase-out</a></li> <li><a href="/wiki/Predicting_the_timing_of_peak_oil" title="Predicting the timing of peak oil">timing</a></li></ul></li> <li><a href="/wiki/Petrocurrency" title="Petrocurrency">Petrocurrency</a></li> <li><a href="/wiki/Petrodollar_recycling" title="Petrodollar recycling">Petrodollar recycling</a></li> <li><a href="/wiki/Petrofiction" title="Petrofiction">Petrofiction</a></li> <li><a href="/wiki/Shale_band" title="Shale band">Shale band</a></li> <li><a href="/wiki/Shale_gas" title="Shale gas">Shale gas</a></li> <li><a href="/wiki/Swing_producer" title="Swing producer">Swing producer</a></li> <li><a href="/wiki/Unconventional_(oil_and_gas)_reservoir" title="Unconventional (oil and gas) reservoir">Unconventional (oil and gas) reservoir</a> <ul><li><a href="/wiki/Heavy_crude_oil" title="Heavy crude oil">heavy crude</a></li> <li><a href="/wiki/Oil_sands" title="Oil sands">oil sands</a></li> <li><a href="/wiki/Oil_shale" title="Oil shale">oil shale</a></li> <li><a href="/wiki/Tight_oil" title="Tight oil">tight oil</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;">Companies and<br />organisations</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Major<br /><a href="/wiki/List_of_oil_exploration_and_production_companies" title="List of oil exploration and production companies">petroleum<br />companies</a></div></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;"><a href="/wiki/Big_Oil" title="Big Oil">Supermajors</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/BP" title="BP">BP</a></li> <li><a href="/wiki/Chevron_Corporation" title="Chevron Corporation">Chevron</a></li> <li><a href="/wiki/Eni" title="Eni">Eni</a></li> <li><a href="/wiki/ExxonMobil" title="ExxonMobil">ExxonMobil</a></li> <li><a href="/wiki/Shell_plc" title="Shell plc">Shell</a></li> <li><a href="/wiki/TotalEnergies" title="TotalEnergies">TotalEnergies</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;"><a href="/wiki/National_oil_company" title="National oil company">National oil<br />companies</a></div></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Abu_Dhabi_National_Oil_Company" title="Abu Dhabi National Oil Company">Abu Dhabi National Oil Company</a></li> <li><a href="/wiki/ANCAP_(Uruguay)" title="ANCAP (Uruguay)">ANCAP</a></li> <li><a href="/wiki/Bharat_Petroleum" title="Bharat Petroleum">Bharat Petroleum</a></li> <li><a href="/wiki/China_National_Offshore_Oil_Corporation" title="China National Offshore Oil Corporation">China National Offshore Oil Corporation</a></li> <li><a href="/wiki/China_National_Petroleum_Corporation" title="China National Petroleum Corporation">China National Petroleum Corporation</a></li> <li><a href="/wiki/Ecopetrol" title="Ecopetrol">Ecopetrol</a></li> <li><a href="/wiki/Equinor" title="Equinor">Equinor</a></li> <li><a href="/wiki/Gazprom" title="Gazprom">Gazprom</a></li> <li><a href="/wiki/Hindustan_Petroleum" title="Hindustan Petroleum">Hindustan Petroleum</a></li> <li><a href="/wiki/Indian_Oil_Corporation" title="Indian Oil Corporation">Indian Oil Corporation</a></li> <li><a href="/wiki/Iraq_National_Oil_Company" title="Iraq National Oil Company">Iraq National Oil Company</a></li> <li><a href="/wiki/KazMunayGas" title="KazMunayGas">KazMunayGas</a></li> <li><a href="/wiki/Kuwait_Petroleum_Corporation" title="Kuwait Petroleum Corporation">Kuwait Petroleum Corporation</a></li> <li><a href="/wiki/Grupa_Lotos" title="Grupa Lotos">Lotos</a></li> <li><a href="/wiki/Naftogaz" title="Naftogaz">Naftogaz</a></li> <li><a href="/wiki/National_Iranian_Oil_Company" title="National Iranian Oil Company">National Iranian Oil Company</a></li> <li><a href="/wiki/National_Iranian_South_Oil_Company" title="National Iranian South Oil Company">National Iranian South Oil Company</a></li> <li><a href="/wiki/NNPC_Limited" title="NNPC Limited">NNPC Limited</a></li> <li><a href="/wiki/Oil_%26_Gas_Development_Company" title="Oil & Gas Development Company">Oil & Gas Development Company</a></li> <li><a href="/wiki/Oil_and_Natural_Gas_Corporation" title="Oil and Natural Gas Corporation">Oil and Natural Gas Corporation</a></li> <li><a href="/wiki/Orlen" title="Orlen">Orlen</a></li> <li><a href="/wiki/PDVSA" title="PDVSA">PDVSA</a></li> <li><a href="/wiki/Pemex" title="Pemex">Pemex</a></li> <li><a href="/wiki/Pertamina" title="Pertamina">Pertamina</a></li> <li><a href="/wiki/Petrobangla" title="Petrobangla">Petrobangla</a></li> <li><a href="/wiki/Petrobras" title="Petrobras">Petrobras</a></li> <li><a href="/wiki/PetroChina" title="PetroChina">PetroChina</a></li> <li><a href="/wiki/Petronas" title="Petronas">Petronas</a></li> <li><a href="/wiki/Petrovietnam" title="Petrovietnam">Petrovietnam</a></li> <li><a href="/wiki/PTT_Public_Company_Limited" title="PTT Public Company Limited">PTT Public Company Limited</a></li> <li><a href="/wiki/QatarEnergy" title="QatarEnergy">QatarEnergy</a></li> <li><a href="/wiki/Rosneft" title="Rosneft">Rosneft</a></li> <li><a href="/wiki/Saudi_Aramco" title="Saudi Aramco">Saudi Aramco</a></li> <li><a href="/wiki/Sinopec" title="Sinopec">Sinopec</a></li> <li><a href="/wiki/SOCAR" title="SOCAR">SOCAR</a></li> <li><a href="/wiki/Sonangol_Group" title="Sonangol Group">Sonangol</a></li> <li><a href="/wiki/Sonatrach" title="Sonatrach">Sonatrach</a></li> <li><a href="/wiki/TPAO" title="TPAO">TPAO</a></li> <li><a href="/wiki/YPF" title="YPF">YPF</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;"><a href="/wiki/Energy_trading" class="mw-redirect" title="Energy trading">Energy trading</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Enron" title="Enron">Enron</a></li> <li><a href="/wiki/Glencore" title="Glencore">Glencore</a></li> <li><a href="/wiki/Gunvor" title="Gunvor">Gunvor</a></li> <li><a href="/wiki/Mercuria" title="Mercuria">Mercuria</a></li> <li><a href="/wiki/Naftiran_Intertrade" title="Naftiran Intertrade">Naftiran Intertrade</a></li> <li><a href="/wiki/Trafigura" title="Trafigura">Trafigura</a></li> <li><a href="/wiki/Vitol" title="Vitol">Vitol</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left; font-weight:normal;">Others</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/APA_Corporation" title="APA Corporation">APA Corporation</a></li> <li><a href="/wiki/Cenovus_Energy" title="Cenovus Energy">Cenovus Energy</a></li> <li><a href="/wiki/Cepsa" title="Cepsa">Cepsa</a></li> <li><a href="/wiki/ConocoPhillips" title="ConocoPhillips">ConocoPhillips</a></li> <li><a href="/wiki/Devon_Energy" title="Devon Energy">Devon Energy</a></li> <li><a href="/wiki/Eneos_Holdings" title="Eneos Holdings">Eneos Holdings</a></li> <li><a href="/wiki/Galp_Energia" title="Galp Energia">Galp Energia</a></li> <li><a href="/wiki/Hess_Corporation" title="Hess Corporation">Hess Corporation</a></li> <li><a href="/wiki/Husky_Energy" title="Husky Energy">Husky Energy</a></li> <li><a href="/wiki/Imperial_Oil" title="Imperial Oil">Imperial Oil</a></li> <li><a href="/wiki/Lukoil" title="Lukoil">Lukoil</a></li> <li><a href="/wiki/Marathon_Oil" title="Marathon Oil">Marathon Oil</a></li> <li><a href="/wiki/Marathon_Petroleum" title="Marathon Petroleum">Marathon Petroleum</a></li> <li><a href="/wiki/Occidental_Petroleum" title="Occidental Petroleum">Occidental Petroleum</a></li> <li><a href="/wiki/OMV" title="OMV">OMV</a></li> <li><a href="/wiki/Phillips_66" title="Phillips 66">Phillips 66</a></li> <li><a href="/wiki/Port_Harcourt_Refining_Company" title="Port Harcourt Refining Company">Port Harcourt Refining Company</a></li> <li><a href="/wiki/Reliance_Industries" title="Reliance Industries">Reliance Industries</a></li> <li><a href="/wiki/Repsol" title="Repsol">Repsol</a></li> <li><a href="/wiki/Suncor_Energy" title="Suncor Energy">Suncor Energy</a></li> <li><a href="/wiki/Sunoco" title="Sunoco">Sunoco</a></li> <li><a href="/wiki/Surgutneftegas" title="Surgutneftegas">Surgutneftegas</a></li> <li><a href="/wiki/TechnipFMC" title="TechnipFMC">TechnipFMC</a></li> <li><a href="/wiki/TNK-BP" title="TNK-BP">TNK-BP</a></li> <li><a href="/wiki/Tullow_Oil" title="Tullow Oil">Tullow Oil</a></li> <li><a href="/wiki/T%C3%BCpra%C5%9F" title="Tüpraş">Tüpraş</a></li> <li><a href="/wiki/Valero_Energy" title="Valero Energy">Valero Energy</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;"><div style="display: inline-block; line-height: 1.2em; padding: .1em 0;">Major<br /><a href="/wiki/List_of_oilfield_service_companies" title="List of oilfield service companies">services<br />companies</a></div></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Amec_Foster_Wheeler" title="Amec Foster Wheeler">Amec Foster Wheeler</a></li> <li><a href="/wiki/Baker_Hughes" title="Baker Hughes">Baker Hughes</a></li> <li><a href="/wiki/Cameron_International" title="Cameron International">Cameron International</a></li> <li><a href="/wiki/CGG_(company)" class="mw-redirect" title="CGG (company)">CGG</a></li> <li><a href="/wiki/CH2M" title="CH2M">CH2M</a></li> <li><a href="/wiki/Chicago_Bridge_%26_Iron_Company" title="Chicago Bridge & Iron Company">Chicago Bridge & Iron Company</a></li> <li><a href="/wiki/China_Oilfield_Services" title="China Oilfield Services">China Oilfield Services</a></li> <li><a href="/wiki/Enbridge" title="Enbridge">Enbridge</a></li> <li><a href="/wiki/GE_Power" title="GE Power">GE Power</a></li> <li><a href="/wiki/Halliburton" title="Halliburton">Halliburton</a></li> <li><a href="/wiki/Nabors_Industries" title="Nabors Industries">Nabors Industries</a></li> <li><a href="/wiki/Naftiran_Intertrade" title="Naftiran Intertrade">Naftiran Intertrade</a></li> <li><a href="/wiki/NOV_Inc." title="NOV Inc.">NOV Inc.</a></li> <li><a href="/wiki/Petrofac" title="Petrofac">Petrofac</a></li> <li><a href="/wiki/Saipem" title="Saipem">Saipem</a></li> <li><a href="/wiki/Schlumberger" title="Schlumberger">Schlumberger</a></li> <li><a href="/wiki/Snam" title="Snam">Snam</a></li> <li><a href="/wiki/Subsea_7" title="Subsea 7">Subsea 7</a></li> <li><a href="/wiki/TC_Energy" title="TC Energy">TC Energy</a></li> <li><a href="/wiki/Transocean" title="Transocean">Transocean</a></li> <li><a href="/wiki/Valaris_Limited" title="Valaris Limited">Valaris Limited</a></li> <li><a href="/wiki/Weatherford_International" title="Weatherford International">Weatherford International</a></li> <li><a href="/wiki/John_Wood_Group" title="John Wood Group">John Wood Group</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;text-align:left;">Others</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/American_Petroleum_Institute" title="American Petroleum Institute">American Petroleum Institute</a></li> <li><a href="/wiki/Canadian_petroleum_companies" title="Canadian petroleum companies">Canadian petroleum companies</a></li> <li><a href="/wiki/Intercontinental_Exchange_Futures" title="Intercontinental Exchange Futures">Intercontinental Exchange Futures</a></li> <li><a href="/wiki/International_Association_of_Oil_%26_Gas_Producers" title="International Association of Oil & Gas Producers">International Association of Oil & Gas Producers</a></li> <li><a href="/wiki/International_Energy_Agency" title="International Energy Agency">International Energy Agency</a></li> <li><a href="/wiki/Society_of_Petroleum_Engineers" title="Society of Petroleum Engineers">Society of Petroleum Engineers</a></li> <li><a href="/wiki/World_Petroleum_Council" class="mw-redirect" title="World Petroleum Council">World Petroleum Council</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><td class="navbox-abovebelow" colspan="2" style="font-weight:bold;"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Petroleum_industry" title="Category:Petroleum industry">Category</a></li></ul> </div></td></tr></tbody></table></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Well_logging&oldid=1208100921">https://en.wikipedia.org/w/index.php?title=Well_logging&oldid=1208100921</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Categories</a>: <ul><li><a href="/wiki/Category:Well_logging" title="Category:Well logging">Well logging</a></li><li><a href="/wiki/Category:Petroleum_production" title="Category:Petroleum production">Petroleum production</a></li><li><a href="/wiki/Category:Economic_geology" title="Category:Economic geology">Economic geology</a></li><li><a href="/wiki/Category:Oil_wells" title="Category:Oil wells">Oil wells</a></li><li><a href="/wiki/Category:Boreholes" title="Category:Boreholes">Boreholes</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:All_articles_with_dead_external_links" title="Category:All articles with dead external links">All articles with dead external links</a></li><li><a href="/wiki/Category:Articles_with_dead_external_links_from_June_2016" title="Category:Articles with dead external links from June 2016">Articles with dead external links from June 2016</a></li><li><a href="/wiki/Category:Articles_with_dead_external_links_from_September_2017" title="Category:Articles with dead external links from September 2017">Articles with dead external links from September 2017</a></li><li><a href="/wiki/Category:Articles_with_permanently_dead_external_links" title="Category:Articles with permanently dead external links">Articles with permanently dead external links</a></li><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Articles_needing_additional_references_from_July_2022" title="Category:Articles needing additional references from July 2022">Articles needing additional references from July 2022</a></li><li><a href="/wiki/Category:All_articles_needing_additional_references" title="Category:All articles needing additional references">All articles needing additional references</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_February_2018" title="Category:Articles with unsourced statements from February 2018">Articles with unsourced statements from February 2018</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 16 February 2024, at 13:42<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. By using this site, you agree to the <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Terms_of_Use" class="extiw" title="foundation:Special:MyLanguage/Policy:Terms of Use">Terms of Use</a> and <a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy" class="extiw" title="foundation:Special:MyLanguage/Policy:Privacy policy">Privacy Policy</a>. Wikipedia® is a registered trademark of the <a rel="nofollow" class="external text" href="https://wikimediafoundation.org/">Wikimedia Foundation, Inc.</a>, a non-profit organization.</li> </ul> <ul id="footer-places"> <li id="footer-places-privacy"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Privacy_policy">Privacy policy</a></li> <li id="footer-places-about"><a href="/wiki/Wikipedia:About">About Wikipedia</a></li> <li id="footer-places-disclaimers"><a href="/wiki/Wikipedia:General_disclaimer">Disclaimers</a></li> <li id="footer-places-contact"><a href="//en.wikipedia.org/wiki/Wikipedia:Contact_us">Contact Wikipedia</a></li> <li id="footer-places-wm-codeofconduct"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Universal_Code_of_Conduct">Code of Conduct</a></li> <li id="footer-places-developers"><a href="https://developer.wikimedia.org">Developers</a></li> <li id="footer-places-statslink"><a href="https://stats.wikimedia.org/#/en.wikipedia.org">Statistics</a></li> <li id="footer-places-cookiestatement"><a href="https://foundation.wikimedia.org/wiki/Special:MyLanguage/Policy:Cookie_statement">Cookie statement</a></li> <li id="footer-places-mobileview"><a href="//en.m.wikipedia.org/w/index.php?title=Well_logging&mobileaction=toggle_view_mobile" class="noprint stopMobileRedirectToggle">Mobile view</a></li> </ul> <ul id="footer-icons" class="noprint"> <li id="footer-copyrightico"><a href="https://wikimediafoundation.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/static/images/footer/wikimedia-button.svg" width="84" height="29" alt="Wikimedia Foundation" loading="lazy"></a></li> <li id="footer-poweredbyico"><a href="https://www.mediawiki.org/" class="cdx-button cdx-button--fake-button cdx-button--size-large cdx-button--fake-button--enabled"><img src="/w/resources/assets/poweredby_mediawiki.svg" alt="Powered by MediaWiki" width="88" height="31" loading="lazy"></a></li> </ul> </footer> </div> </div> </div> <div class="vector-settings" id="p-dock-bottom"> <ul></ul> </div><script>(RLQ=window.RLQ||[]).push(function(){mw.config.set({"wgHostname":"mw-web.codfw.main-f68f4df69-9g6mf","wgBackendResponseTime":167,"wgPageParseReport":{"limitreport":{"cputime":"0.642","walltime":"0.808","ppvisitednodes":{"value":2475,"limit":1000000},"postexpandincludesize":{"value":111495,"limit":2097152},"templateargumentsize":{"value":3854,"limit":2097152},"expansiondepth":{"value":17,"limit":100},"expensivefunctioncount":{"value":18,"limit":500},"unstrip-depth":{"value":1,"limit":20},"unstrip-size":{"value":100587,"limit":5000000},"entityaccesscount":{"value":0,"limit":400},"timingprofile":["100.00% 664.023 1 -total"," 34.96% 232.114 1 Template:Reflist"," 18.15% 120.509 8 Template:Cite_web"," 18.08% 120.036 1 Template:Well_logging"," 17.78% 118.049 1 Template:Sidebar"," 12.38% 82.207 4 Template:Navbox"," 11.44% 75.987 1 Template:Short_description"," 10.54% 69.959 1 Template:More_citations_needed"," 10.49% 69.682 1 Template:Petroleum_industry"," 9.77% 64.866 1 Template:Ambox"]},"scribunto":{"limitreport-timeusage":{"value":"0.357","limit":"10.000"},"limitreport-memusage":{"value":7151653,"limit":52428800}},"cachereport":{"origin":"mw-api-int.codfw.main-7cc866bdbb-9qk6d","timestamp":"20241206193240","ttl":2592000,"transientcontent":false}}});});</script> <script type="application/ld+json">{"@context":"https:\/\/schema.org","@type":"Article","name":"Well logging","url":"https:\/\/en.wikipedia.org\/wiki\/Well_logging","sameAs":"http:\/\/www.wikidata.org\/entity\/Q2383566","mainEntity":"http:\/\/www.wikidata.org\/entity\/Q2383566","author":{"@type":"Organization","name":"Contributors to Wikimedia projects"},"publisher":{"@type":"Organization","name":"Wikimedia Foundation, Inc.","logo":{"@type":"ImageObject","url":"https:\/\/www.wikimedia.org\/static\/images\/wmf-hor-googpub.png"}},"datePublished":"2004-10-28T14:47:49Z","dateModified":"2024-02-16T13:42:59Z","headline":"measuring of physical parameters of the formations crossed by a borehole"}</script> </body> </html>