Orderliness of hydrocarbon distribution in the Longfengshan area of the Changling fault depression, Songliao Basin, and its main controlling factors
Fan Jie;Jiang Youlu;Liu Jingdong;Zhu Jianfeng;Li Ruilei;School of Geosciences, China University of Petroleum-Huadong;Sinopec Northeast Oil and Gas Company;
The orderliness of hydrocarbon distribution in the Songliao Basin has benn rarely studied and its main controlling factors have not defined yet, which impedes the oil and gas exploration in this area to certain extent. In this paper, the Longfengshan area in the Changling fault depression, a new exploration area in the Songliao Basin, was taken as an example to describe the orderliness of hydrocarbon distribution from the aspects of reservoir type, reserves abundance and hydrocarbon phase state. Then, based on hydrocarbon accumulation conditions, three hydrocarbon migration–accumulation units(S2, S203 and S201) were classified. Finally, the configuration of hydrocarbon accumulation elements was assessed quantitatively using the analytic hierarchy process, and the main factors controlling the hydrocarbon distribution regularity were defined. The following results were obtained. First, from the sag belt in the north to the structural belt in the west, the hydrocarbon phase state changes in an order of gas reservoir–oil gas reservoir–oil reservoir, the reservoir type presents a gradual change of lithologic reservoir–structural-lithologic reservoir–lithologic-structural reservoir–structural reservoir, and the hydrocarbon reserves and abundance increase gradually. Second, the orderliness of hydrocarbon distribution in the study area is controlled by three factors. The orderliness of hydrocarbon phase state is controlled by the effectiveness of fault–source space–time configuration; that of reservoir type is controlled by the diversity of boundary conditions of hydrocarbon migration-accumulation units; and that of hydrocarbon enrichment degree is controlled by the diversity of fault–source–sandstone–caprock configuration. From the sag belt in the north to the structural belt in the west, the fault–source–sandstone–caprock configuration turns better and the hydrocarbon migration–accumulation capacity becomes stronger. In conclusion, S201 is the best in hydrocarbon accumulation conditions, source–fault–sandstone–caprock configuration and exploration potential, so it can be taken as a main target for future exploration.
【CateGory Index】： P618.13
【CateGory Index】： P618.13