New understanding of petroleum geological conditions of Wensu bulge in Tarim Basin, Xinjiang

In order to solve the key geological problems, such as the tectonic evolution, oil source conditions and the trap type in Wensu bulge, the authors ascertained the key factors of oil and gas accumulation and put forward the new cognitions about petroleum geology, through the comprehensive analysis of petroleum geological conditions and the results of sample test. The results show that Wensu bulge is an inherited developmental paleo-uplift, and the tectonic evolution has experienced four stages. Wensu bulge reservoir type is dominated by tectonic-lithologic types, without the development of source rocks, but it developed a high-efficiency system for communication with the hydrocarbon-rich sag in Baicheng. The reservoirs of Jidike Formation of the Neogene in Wensu bulge are dominated by tectonic-lithologic reservoirs. The hydrocarbon generation, migration and accumulation mainly occured in the Neogene-Quaternary, with obvious characteristics of late complex accumulation. The superior caprock conditions are important factors for the formation of reservoirs in Jidike Formation.