The structural characteristics and sand controlling models of Xianqiao Low Uplift in Lishui Sag,East China Sea Shelf Basin
The present drilling results show that determining the distribution of sand bodies to the east of Xianqiao Low Uplift is the key to locating the next oil and gas exploration target in the northern Lishui Sag.Based on the 3D seismic data and the surrounding exploration wells,this paper studies the tectonic evolution,structural style,fault system,and fault activity,analyzes the structural characteristics of Xianqiao Low Uplift,then summarizes the sedimentary control of Xianqiao Low Uplift on the eastern sub-sag from the perspective of structure.Xianqiao Low Uplift in Lishui Sag is a slope-horst structure formed during rifting and develops two structural styles:horst and half-horst.The west-dipping Xianqiao Fault is the fault zone formed by the growth and linkage of a series of isolated faults during rift initiation stage.In the rift waning stage,the hard-connected fault zone gradually evolved into relay ramps.Due to the strong fault activity during the rift climax stage,the sedimentation to the east Xianqiao Low Uplift is mainly characterized by a fault-controlled depositional model.Then during the rift waning stage,the drainage system flowed across Xianqiao Low Uplift and entered the eastern sub-sag through relay ramps,forming a relay-ramp-controlled depositional model.In the eastern part of Xianqiao Low Uplift,two large deltas(at the north and the south)were identified around the relay ramp which formed in the rift waning stage,providing a clear direction for oil and gas exploration in this area.
structural characteristicsrelay rampsand controlling modelLishui Sag
万方数据
维普
