辽河西部凹陷曙光古潜山断裂特征及控油气作用OA

Shuguang buried hill area serves as a crucial area for hydrocarbon production increase in western sag of Liaohe Depression.Multi-stage complex faults control its structural framework and hydrocarbon distribution,hinder-ing deep exploration of buried hill reservoirs.Aiming at the problems of unclear understanding of fault staging and transport-sealing capacity,and weakening fault controlling mechanisms on the whole process of hydrocarbon"migra-tion-accumulation-preservation"in Shuguang buried hill belt,structural evolution history,fault sealing capacity and the relationship between faults and hydrocarbon distribution are comprehensively analyzed based on seismic inter-pretation,drilling,well testing,and formation testing data.The characteristics and evolutionary processes of faults in Paleozoic and Proterozoic Shuguang buried hills are systematically studied,as well as fault control on hydrocarbon reservoirs accumulation and distribution.The results indicate that,faults in Paleozoic and Proterozoic Shuguang area primarily exhibit NE-strike distribution,with secondary faults oriented nearly E-W and nearly S-N strike.The faults are divided into 3 stages,including reverse faults from the A-episode of Yanshanian Movement,normal faults from B-episode of Yanshanian Movement,and normal faults from Himalayan Movement.Himalayan faults have larger throws and dip angles,strongly facilitating hydrocarbon transportation.Secondary faults of Yanshanian period have smaller fault throws and relatively gentler dip angles,predominantly dipping westward and southward,and acting as sealing faults,which is conducive to hydrocarbon sealing.Fault sealing in different areas varies significantly.When Shale Gouge Ratio ISGR≥23%,fault lateral sealing is better,which is more favorable for hydrocarbon accumulation.The research provides a theoretical basis for oil and gas exploration in this area,with significant guidance for favor-able areas optimization.