Hydrocarbon generative potential and thermal maturity of newly discovered coal seams from Bapung Coalfield, Meghalaya, India: Rock-Eval pyrolysis and organic petrographic analysis

The present study systematically investigates a newly discovered coal seam in Bapung Coalfield, Meghalaya, on eighteen samples to determine the origin of organic matter, thermal maturity, hydrocarbon richness, and petroleum generation potential(GP). The data obtained from the geochemical study show that the samples contain a significant quantity of organic matter, and free hydrocarbon value suggests excellent source rock potential. Similarly, the hydrocarbon richness value ranges from 68.10 to 588.63, demonstrating an emphatic possibility for oil and gas generation in all studied samples. Tmax and Ro% data of studied sediments indicate that most of the analysed samples are thermally immature, and some of them attain maturity (oil window) for petroleum generation but is not able to produce hydrocarbon at the commercial level. The pseudo Van Krevelen (HI Vs OI) and TOC Vs released hydrocarbon yield diagrams show that organic matter is mainly Type II and II–III kerogens, thus can be contemplated as a fair oil source and gas/oil source rock. Excellent positive correlations were found between oil yield (R2 = 0.99) and vitrinite (R2 = 0.98) with conversion (%), signifying its suitability for liquid hydrocarbon generation in future. Overall the results indicate that the formation (source rock) can generate hydrocarbon and may produce oil and gas through gasification and liquefaction.