Control Of Faults In Qinan Area On Hydrocarbon Accumulation In The Lower Sub-member Of Sha 1 Member

Qinan area is located in the south of Qikou Sag in Bohai Bay Basin.The lower lower sub-member of Sha 1 Member is the main oil and gas bearing layer,and its oil and gas distribution is obviously controlled by faults.Whether the control effect of faults on the oil and gas accumulation in the lower sub-member of Sha 1 Member is the key to correctly understand the oil and gas distribution law and guide the oil and gas exploration.On the basis of the study of regional structure,stratigraphic sedimentation and souring-reservoir-cap assemblage characteristics,this paper uses the results of three-dimensional geological data interpretation to study the fault development and activity characteristics of the lower sub-member of Sha 1 Member in Qinan area,classifying the fault system and determining the oil source faults.Based on the research on the types and distribution of oil reservoirs found in the lower sub-member of Sha 1 Member in Qinan area and the relationship between other faults,this paper expounds the fault-controlled accumulation,summarizes the fault-controlled accumulation mode,predicts the favorable areas for accumulation,and optimizes the favorable targets for accumulation.Based on the above research,the specific research results are as follows:(1)the disambiguation sand at the period of oil source faults is mainly distributed in the northeast,conducting faults are mainly distributed in the south and west,and keep out fracture distribution in the region.The south and the north and east west development.(2)The faults in the lower sub-member of Sha 1 Member in Qinan area control the hydrocarbon accumulation in the following ways: 1)They provide the transport channel for vertical and lateral hydrocarbon migration;2)The structures and fault sand traps controlled by faults provide places for oil and gas accumulation.(3)There are two modes of hydrocarbon accumulation in the lower sub-member of Sha 1 Member in Qinan area.One is the hydrocarbon accumulation mode in the source rock area,and the other is the hydrocarbon accumulation mode in the slope area outside the source area.(4)The faults control the distribution range of favorable areas for hydrocarbon accumulation in the lower sub-member of Sha 1 Member in Qinan area.The favorable areas for hydrocarbon accumulation are mainly distributed near faults,such as Nandagang,Zhangdong,Zhangbei,Zhaobei,Koucun and Yangbei faults.The above research results have an important reference role in guiding oil and gas exploration in the lower sub-member of Sha 1 Member in Qinan area.