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Oil correlation case history: Brazilian offshore basins (view source)
Revision as of 23:05, 4 March 2014
, 23:05, 4 March 2014→Parameters measured
==Parameters measured==
==Parameters measured==
To understand the source families responsible for the oils on the Brazilian margin, Mello et al.<ref name=ch08r30 />) measured numerous elemental, isotopic, and molecular characteristics for about 50 oils; 16 of these were examined using techniques of semiquantitative biomarker analysis. Their study is an excellent example of the importance of using diversified analytical methods. A partial list of the parameters measured includes δ<sup>13</sup>C of the whole oil; sulfur content; vanadium–nickel ratio; compound-class distribution; pristane–phytane ratio; various biomarker ratios involving diasteranes, methylsteranes, tricyclic terpanes, bisnorhopane, and gammacerane; and semiquantitative concentration data for various isoprenoids, β-carotane, selected steranes, hopanes, and oleanane. This set of parameters was then used to classify the oils into five source-distinctive groups. No one or two correlative parameters could establish these groupings—only through the combined use of several elemental, isotopic, and molecular parameters could the correlations be made and depositional settings inferred.
To understand the source families responsible for the oils on the Brazilian margin, Mello et al.<ref name=ch08r30 /> measured numerous elemental, isotopic, and molecular characteristics for about 50 oils; 16 of these were examined using techniques of semiquantitative biomarker analysis. Their study is an excellent example of the importance of using diversified analytical methods. A partial list of the parameters measured includes δ<sup>13</sup>C of the whole oil; sulfur content; vanadium–nickel ratio; compound-class distribution; pristane–phytane ratio; various biomarker ratios involving diasteranes, methylsteranes, tricyclic terpanes, bisnorhopane, and gammacerane; and semiquantitative concentration data for various isoprenoids, β-carotane, selected steranes, hopanes, and oleanane. This set of parameters was then used to classify the oils into five source-distinctive groups. No one or two correlative parameters could establish these groupings—only through the combined use of several elemental, isotopic, and molecular parameters could the correlations be made and depositional settings inferred.
==Group I oils, freshwater lacustrine setting==
==Group I oils, freshwater lacustrine setting==