On bacterial role in hydrocarbon generation mechanism, Banqiao Sag

摘要

Terrestrial organic matter is a main primary source material for oil and gas generation in the Eogene Shahejie Formation in Banqiao Sag, bacterial degradation and reworking of sedimentary organic matter would be conducive to the enhancement of its sapropelification level and to the early generation of immature oil. Bacteria-derived short-chain alkanes are a major material base for the light hydrocarbon formation of condensate and crude oil in Banqiao Sag, certain thermal maturation, formation temperature and pressure are external conditions for the condensate formation. The establishment of hydrocarbon generation model should be favorable to the resource prediction of deep-lying high-mature and shallow-lying immature oils and gases.