Hydrocarbon source rock potential of Paleocene and Jurassic deposits in the Panjpir oilfield subsurface, Punjab Platform, Pakistan

Abstract

Hydrocarbon source rock potential of three formations in Panjpir oilfield in Punjab Platform in the eastern part of the Middle Indus Basin, namely Ranikot (Paleocene), Samanasuk (Jurassic), and Shinwari (Jurassic) was investigated by using total organic carbon (TOC) and Rock-Eval pyrolysis analysis measurements. Nine samples were obtained from producing well. The analyzed samples contain TOC ranging between 0.98 and 2.45 wt.%. S2 values of Rock-Eval show poor potential with values ranging from 0.02 to 0.27 mg HC/g rock. The samples have low hydrogen index values ranging from 3 to 27 mg HC/g TOC and also having low Tmax values ranging from 427 to 431 °C. On the basis of analysis performed, only three studied samples have early maturity, two from Ranikot and one from Samana Suk formation, whereas rest of the samples are in immature zones as indicated by HI vs Tmax plot; no samples from Shinwari Formation lie in maturity window. All of the samples have kerogen Type III and have poor generation potential. Hence, from the result, some minor gas could be expected to have been generated in the study area.