Genesis and entrapment of hydrocarbons within multi-layered Tertiary clastic reservoirs of Geleki field, Upper Assam Basin, India

摘要

An oil generation-migration and entrapment model developed from an integrated geochemical-palynological study explains the distribution of oils discovered in multi-layered Tertiary clastic reservoirs of Geleki field. It can be used as a predictive model for future exploration. The study indicates three genetic types of oils in this field. Generation of hydrocarbons in this field has occurred over a maturity range of 0.45-0.65% Ro. Onset of oil generation in the area started in Late Pliocene time. Migration distances are short and vertical. Quantification of the oil charge to the area indicates that there is an enormous hydrocarbon potential in the form of small sized pools.