Source rock analysis, thermal maturation and hydrocarbon generation using rock-eval pyrolysis in parts of Krishna–Godavari basin, India: a case study

Among the various techniques available, the geochemical technique involving total organic carbon content (TOC) and rock-eval pyrolysis are regularly being used in hydrocarbon exploration. They provide information on the kerogen type, sedimentary environment, effective source rock identification and its thermal maturity. In the present study, core samples from three deep boreholes in Krishna–Godavari basin are analyzed to understand the hydrocarbon scenario in parts of the basin. Based on TOC and rock-eval pyrolysis significantly thick, indigenous immature to early mature gas-prone shales from borehole GERMI #1; while non-indigenous, early mature to mature oil and gas-prone shales from borehole GERMI #2 and GERMI #3. Interpreted hydrocarbon typing is supported by well-testing analysis. Break in vitrinite reflectance (R o) profile is also observed; indicative of significant erosion during Late Cretaceous sedimentation due to tectonic uplift during this time and associated high heat flow causes for thermal maturation of overlying units.