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<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Matthew K. Landon</dc:contributor>
  <dc:contributor>Peter B. McMahon</dc:contributor>
  <dc:contributor>Justin T. Kulongoski</dc:contributor>
  <dc:contributor>Andrew G. Hunt</dc:contributor>
  <dc:contributor>Tracy Davis</dc:contributor>
  <dc:creator>Robert Anders</dc:creator>
  <dc:date>2022</dc:date>
  <dc:description>&lt;div id="abs0010"&gt;&lt;h3 id="sect0010" class="u-h4 u-margin-m-top u-margin-xs-bottom"&gt;Study region&lt;/h3&gt;&lt;p id="sp0050"&gt;Santa Barbara County, California, USA.&lt;/p&gt;&lt;/div&gt;&lt;div id="abs0015"&gt;&lt;h3 id="sect0015" class="u-h4 u-margin-m-top u-margin-xs-bottom"&gt;Study focus&lt;/h3&gt;&lt;p id="sp0055"&gt;To analyze a wide array of newly collected chemical, isotopic, dissolved gas, and age dating tracers in conjunction with historical data from groundwater and oil wells to determine if water and/or thermogenic gas from oil-bearing formations have mixed with groundwater in the Orcutt Oil Field and surrounding area.&lt;/p&gt;&lt;/div&gt;&lt;div id="abs0020"&gt;&lt;h3 id="sect0020" class="u-h4 u-margin-m-top u-margin-xs-bottom"&gt;New hydrological insights for the region&lt;/h3&gt;&lt;p id="sp0060"&gt;&lt;span&gt;Three of 15 groundwater samples had compositions indicating potential mixing with water and/or thermogenic gas from oil-bearing formations. Relevant indicators included&amp;nbsp;salinity&amp;nbsp;tracers (TDS, Cl, Br), NH&lt;/span&gt;&lt;sub&gt;3,&lt;/sub&gt;&lt;span&gt;&amp;nbsp;DOC, enriched δ&lt;/span&gt;&lt;sup&gt;13&lt;/sup&gt;C-DIC, δ&lt;sup&gt;2&lt;/sup&gt;H-CH&lt;sub&gt;4&lt;/sub&gt;, δ&lt;sup&gt;13&lt;/sup&gt;C-CH&lt;sub&gt;4&lt;/sub&gt;, and δ&lt;sup&gt;13&lt;/sup&gt;C-C&lt;sub&gt;2&lt;/sub&gt;H&lt;sub&gt;6&lt;/sub&gt;&lt;span&gt;&amp;nbsp;values, and trace amounts of C3-C5 gas. The potential sources/pathways for oil-bearing formation water and/or thermogenic gas in groundwater overlying and adjacent to the Orcutt Oil Field include: (1) upward movement from formations developed for oil production due to: (a) natural migration; or (b)&amp;nbsp;anthropogenic activity&amp;nbsp;such as injection and/or movement along wellbores; and (2) oil and gas shows in overlying non-producing oil-bearing formations. Groundwater age tracers, elevated&amp;nbsp;&lt;/span&gt;&lt;sup&gt;4&lt;/sup&gt;&lt;span&gt;He concentrations, and&amp;nbsp;isotopic compositions&amp;nbsp;of noble gases indicated legacy produced water ponds were not a source. This phase of the study relied on samples and data from existing infrastructure. Additional data on potential end-member compositions from new and existing wells and assessments of potential vertical head gradients and pathways between oil and groundwater zones may yield additional insight.&lt;/span&gt;&lt;/p&gt;&lt;/div&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/j.ejrh.2022.101065</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Occurrence of water and thermogenic gas from oil-bearing formations in groundwater near the Orcutt Oil Field, California, USA</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>