Assessment of hydrocarbon generative potential of Late Paleocene coals from East Khasi Hills, Meghalaya, North-East India

Abstract

The study area is situated in the Meghalaya state (East Khasi Hills), North-East India. The notable petroliferous basins that were formed during the Paleogene time occurred in the state of northeast India. This work focused on characterizing the source rock of Late Paleocene (Shella Formation) of Pynursla-Lynkerdem area, East Khasi Hills, Meghalaya for their hydrocarbon potential based on Rock-Eval pyrolysis and elemental data. The coals of the Pynursla-Lynkerdem area have been characterized by high total organic carbon (TOC) range between 67.2 wt% and 74.5 wt%. The remaining hydrocarbon yield (S₂) ranges from 215.5 to 294.0 mg HC/g rock. S₂ and TOC data plots entail that these coals contain Type II–III kerogen and can act as a good hydrocarbon source rock. The hydrogen index (HI) ranges from 311.1 to 405.7 mg HC/g TOC, which indicates most of the sample can generate gases. T_max varies between 405 and 433 °C (less than 435 °C), revealing the immaturity of organic matter. The plot of elemental composition places these samples from sub-bituminous to high volatile bituminous in rank and furnishes these coals’ suitability for gasification.

Keywords:

• hydrocarbon generation potential
• kerogen
• Late Paleocene coals
• thermal maturity
• utilization potential

Acknowledgment

The authors gratefully acknowledge GM and management authorities of KDM Institute of Petroleum Exploration, ONGC, Dehradun for extending laboratory facilities for analytical work.

Disclosure statement

The authors declare no competing interest.