Assessing the potential for hydrocarbon generation in early Eocene and Paleocene sequences of the Punjab Platform Basin, Pakistan, through geochemical and petrophysical analysis

A study was carried out in the Punjab Platform Basin located in Pakistan to evaluate the potential for hydrocarbon in the early Eocene and Paleocene sequences using petrophysical and geochemical techniques. The assessment of reservoir properties for the Sakesar Formation was carried out using wireline logs, which included measurements of water saturation, hydrocarbon saturation, and porosity. Moreover, 21 well-cutting samples were collected to assess the source rock potential of the Nammal (early Eocene), Dungan, and Ranikot (Paleocene) Formations. The results showed that the Nammal and Dungan Formation samples had low to moderate TOC content, ranging from 0.21 to 2.04 wt.% and 0.45 to 0.56 wt.%, respectively, while the Ranikot Formation samples had moderate to high TOC content, ranging from 0.48 to 1.63 wt.%. The formations under study were found to have a low potential for generating hydrocarbons, as indicated by their S2 values ranging from 0.21 to 2.04 mg HC/g rock. The primary type of kerogen present in these formations was type III and mixed type II/III kerogen, and several plots confirmed the poor generative potential of these formations. The analysis of the Sakesar Formation revealed that it had higher porosity levels at depths of approximately 4163–4197 ft4, with average porosity ranging between 8 and 14% and 68.28% SH and 31.71 Sw, indicating moderate to poor reservoir potential. These findings suggest that the Sakesar Formation could potentially be a moderate-to-good reservoir.