Characterization of upper palaeozoic organic-rich units in Svalbard Implications for the petroleum systems of the Norgewian barents shelf
Nicolaisen, J.B. Elvebakk, G. Ahokas, J. Bojesen-KOefoed, J.A. Olaussen, S. Rinna, J. Skeie, J.E. Stemmerik, L.
Characterization of upper palaeozoic organic-rich units in Svalbard Implications for the petroleum systems of the Norgewian barents shelf - ene. 2019 - 19 p. ; 59-78
Transcripción del resumen del autor: Recent discoveries of hydrocarbons along the western margin of the Norwegian Barents Shelf have emphasised the need for a better understanding of the source rock potential of the Upper Palaeozoic succession. In this study, a comprehensive set of organic geochemical data have been collected from the Carboniferous – Permian interval outcropping on Svalbard in order to re-assess the offshore potential. Four stratigraphic levels with organic-rich facies have been identified: (i) Lower Carboniferous (Mississippian) fluvio-lacustrine intervals with TOC between 1 and 75 wt.% and a cumulative organic-rich section more than 100 m thick; (ii) Upper Carboniferous (Pennsylvanian) evaporite-associated marine shales and organic-rich carbonates with TOC up to 20 wt.%; (iii) a widespread lowermost Permian organic-rich carbonate unit, 2–10 m thick, with 1–10 wt. % TOC; and (iv) Lower Permian organic-rich marine shales with an average TOC content of 10 wt.%. Petroleum can potentially be tied to organic-rich facies at formation level based on the gammacerane index, d13C of the aromatic fraction and/or the Pr/Ph ratio. Relatively heavy d13C values, a low gammacerane index and high Pr/Ph ratios characterize Lower Carboniferous non-marine sediments, whereas evaporite-associated facies have lighter d13C, a higher gammacerane index and lower Pr/Ph ratios.
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Characterization of upper palaeozoic organic-rich units in Svalbard Implications for the petroleum systems of the Norgewian barents shelf - ene. 2019 - 19 p. ; 59-78
Transcripción del resumen del autor: Recent discoveries of hydrocarbons along the western margin of the Norwegian Barents Shelf have emphasised the need for a better understanding of the source rock potential of the Upper Palaeozoic succession. In this study, a comprehensive set of organic geochemical data have been collected from the Carboniferous – Permian interval outcropping on Svalbard in order to re-assess the offshore potential. Four stratigraphic levels with organic-rich facies have been identified: (i) Lower Carboniferous (Mississippian) fluvio-lacustrine intervals with TOC between 1 and 75 wt.% and a cumulative organic-rich section more than 100 m thick; (ii) Upper Carboniferous (Pennsylvanian) evaporite-associated marine shales and organic-rich carbonates with TOC up to 20 wt.%; (iii) a widespread lowermost Permian organic-rich carbonate unit, 2–10 m thick, with 1–10 wt. % TOC; and (iv) Lower Permian organic-rich marine shales with an average TOC content of 10 wt.%. Petroleum can potentially be tied to organic-rich facies at formation level based on the gammacerane index, d13C of the aromatic fraction and/or the Pr/Ph ratio. Relatively heavy d13C values, a low gammacerane index and high Pr/Ph ratios characterize Lower Carboniferous non-marine sediments, whereas evaporite-associated facies have lighter d13C, a higher gammacerane index and lower Pr/Ph ratios.
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