Hydrocarbon Kitchen Evolution of E2s3 Source Rocks in the Bohai Offshore Area, North China

Abstract

AbstractThe hydrocarbon kitchen is appropriate for characterizing the center of providing hydrocarbon, and the research on its evolution has a great significance for petroleum exploration. The Bohai offshore area is located in the offshore Bohai Bay basin, North China. It is one of the most petroliferous basins in China. There developed four sets of potential source rocks in the Paleocene. The third member of the Shahejie Formation (E2s3) is the most important source rock. In this paper, the evolution histories of the maturation and hydrocarbon generation & expulsion of E2s3 source rocks are modeled based on the depositional and tectonic development history in combination with geochemical and thermal parameters. The hydrocarbon kitchen evolution of the E2s3 source rocks is analyzed using the amount of expelled hydrocarbon of the E2s3 source rocks in the main geological periods. The result shows that there developed two hydrocarbon kitchens at early stage, which then transformed to one main hydrocarbon kitchen and co‐existing multi‐hydrocarbon kitchens with the geological evolution, e.g. two hydrocarbon kitchens in the Bozhong and Qikou sags in the Paleocene and one main hydrocarbon kitchen in the Bozhong sag and multi‐kitchens in the Qikou, Nanpu, Huanghekou, Liaozhong, Liaoxi and Qinnan sags from the Neogene to the present day. Most oil and gas fields are located in the uplifts and slopes around the main hydrocarbon kitchens, thus the study may provide new insights for understanding the petroleum exploration potential of the Bohai offshore area.