Evaluation of hydrocarbon potential of Gadvan Formation in Binak, Gachsaran and Marun fileds by geochemical methods and thermal modeling

Investigation on hydrocarbon source rock potentiality of Gadvan Formation in Marun, Gachsaran and Binak oil fields using Rock-eval pyrolysis shows that Gadvan Formation in Marun and Gachsaran oil fields is an effective source rock and is capable of generating hydrocarbon (oil and gas), whereas the same formation in the Binak oil field has no hydrocarbon generation potential. The presence of organic matter in Gadvan Formation from Marun and Gachsaran oil fields suggests a mixture of kerogen type II/III and in Binak oil field kergen type III is dominant. Based on Tmax values derived from Rock-Eval pyrolysis, Gadvan Formation in Marun and Gachsaran oil fields is thermally mature and entered oil window stage but in Binak oil field this formation is immature and has not entered oil window yet. The results obtained from pyrolysis and virtinite reflectance measurements are in good agreement with thermal history modeling using PBM software program. Organic facies curve plotted for the Gadvan Formation indicates organic facies BC for Marun and Gachsaran oil fields and organic facies CD for Binak oil field suggesting marine persistent anoxic to oxidizing conditions prevailed during early deposition.