The Relationship Between Structure And Hydrocarbon Accumulation Of The Carboniferous Reservoir At Northern Chepaizi Area

The Chepaizi area is located in the west margin of the Junggar Basin,since 2009,the Shengli Oilfield Sub-Company has carried out exploration work in Pai6 area of its northern.So far its controlled reserve has been cumulatively reported to 3589×104t.However,there are many restricts to the exploration and development for the igneous reservoir,the reservoir space type and condition are unclear,the hydrocarbon source condition and migration are unclear,the reservoir type and controlling factors are unclear,the favorable exploration area and prospects are unclear.In this paper with the studies of structural characteristics as the starting point,Integrated with previous study,lithoface characteristics and seismic data,the locations of prospective Carboniferous reservoir are primarily predicted.The Chepaizi Uplift located at the front of the nappe structure is where the fractures concentrated.The fracture is the main controlling factor of hydrocarbon accumulation.The prospects located at the successive tectonic highs and are the long-term hydrocarbon migration destination.The result shows that,the Chepaizi Uplift was influenced by the thrusting from west to east.Many south-north striking faults were developed in this area,subparalleling to Hongche Fault and separating the Chepaizi Carboniferous layers into three south-north directed prospective zones,with areas in total of 250km2.The controlling faults in the three zones and the northwest-southeast,east-west striking faults formed effective structural traps and hydrocarbon accumulation areas.The first zone mainly contains the east of north Cheqian15 Fault-Pai61 Fault and the west of Hongche Fault.Fractures were well developed in this zone and it is located on the hydrocarbon migration path.It is the most potential zone with big oil and gas field of thick reservoir,good hydrocarbon quality and high productivity discovered.The second zone is between the north Cheqian15 Fault-Pai61 Fault and west Pai62 Fault-Pai6 Fault.This zone also presents relatively good exploration potential with abundant oil and gas shows and relatively heavy oil quality.The third zone is to the west of west Pai62 Fault-Pai6 Fault.It is relatively far away from the hydrocarbon source and is regarded as potential area for exploration.