Evaluation of hydrocarbon generative potential of Pabdeh source rock in Ramin Oilfield, Dezful Embayment, SW Iran

Document Type : Research Paper

Authors

Abstract

The one of the most important petroleum source rocks in the Zagros basin is the Pabdeh Formation that has been investigated by geochemical techniques. The aim of this study was to assess the quality of organic matter, evaluate thermal evolution and highlight Pabdeh Formation potential as a source rock of Ramin oilfield located in Dezful Embayment. Based on HI versus Tmax and HI versus OI diagrams were used in classifying the organic matter in the formation indicating the presence of Type II kerogen. Most samples of the Pabdeh formation have Tmax values more than 435ºC indicate that the shale of formation is thermally mature with respect to petroleum generation. Hydrogen Index (HI) values range from 150 to 350mgHC/gTOC and S1 + S2 yields values ranging from 11.98 to 31.06mgHC/g rock, suggesting that the shale have oil generating potential.The TOC of shale samples of the studied Ramin Well no. 4 ranges from 1.82 to 3.5%, an indication of a very good source rock of terrestrially derived organic matter. So, investigation of the variation S1 + S2 and TOC parameters indicated that Pabdeh Formation (in the well) is assessed a good source rocks in producing hydrocarbon. Also with T max examination showed that formation is mature enough to generate hydrocarbon and has yet entered oil generation window.

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