关键词: 渤海湾盆地, 海域, 构造转换带, 分段断层, 应变守衡, 油气成藏

Abstract: Based on the 3D seismic profiles and displacement-distance scaling, the relationship between JZ25-1S transfer zone and hydrocarbon accumulation was analyzed in Liaodongwan offshore of Bohai Bay Basin. There are numerous faults of varying scales in JZ25-1S area, and the NE-trending faults are predominant. JZ25-1S transfer zone is located at the three echelon overstepping faults with the NW-dipping, including Liaoxi-1 fault, Liaoxi-2 fault and Liaoxi-3 fault. According to the features of the faults and their assemblages, the JZ25-1S transfer zone was classified into the relay ramp, where fault blocks were formed. The displacement-distance analysis showed that the displacement transfer and strain conservation of the three segmented faults were accomplished mainly in JZ25-1S transfer zone. JZ25-1S transfer zone had also important influence on the formation of the structural traps, spatial distribution of sedimentary systems and hydrocarbon migration, as well as the reservoir properties in the study area. The transfer zones in the overstepping normal faults with the same dip are the favorable objectives for oil and gas exploration in the offshore part of Bohai Bay Basin.

Key words: Bohai Bay Basin, offshore, structural transfer zone, segmented fault, strain conservation, hydrocarbon accumulation