Hydrocarbon generation history constrained by thermal history and hydrocarbon generation kinetics: A case study of the Dongpu Depression, Bohai Bay Basin, China

Abstract

With the increasing exploration and development of typical hydrocarbon-rich depressions, such as the Dongpu Depression, the exploitation difficulty of shallow formations is increasing. There is an urgent need to clarify the hydrocarbon generation mode and hydrocarbon generation histories in deep formations. In this study, a gold tube-autoclave closed system was used to simulate the hydrocarbon generation processes and establish the hydrocarbon generation mode of different types of kerogen. Then, constrained by the thermal history and hydrocarbon generation kinetics, hydrocarbon generation histories were modeled. The results show that hydrocarbon generation evolution can be divided into five stages, and the maturity of each stage is different. The hydrocarbon generation history of the source rocks of the Shahejie 3 Formation mainly dates from the early depositional period of the Shahejie 1 Formation to the middle depositional period of the Dongying Formation. Hydrocarbon generation history constrained by thermal history and hydrocarbon generation kinetics is more in line with actual geological conditions. Moreover, this research can provide important hydrocarbon generation parameters for deep oil and gas exploration and exploitation of the Shahejie 3 Formation in the Dongpu Depression.