Characteristics of low-order accommodation zone and its reservoir formation model in Xin 183 Block, Dongying Sag, Eastern China

This paper investigates the nature of an East-West strike convergent-overlapping accommodation zone in Xin 183 fault block and its influence on the hydrocarbon distribution based on a study of the fault geometry, kinematics and dynamics using 3-D seismic data, well testing data and hydrocarbon distribution data. First, a geometrical analysis indicates that the structural profile of the major fault on the west side and its associated secondary faults has a multi-stage reverse Y appearance; the profile tectonic style on the east side has a cabbage-like appearance. Second, the observed fault activities show that when the activity of the west main fault became weak, the displacement was transferred to east main fault and secondary faults. Third, a dynamical analysis demonstrates that the stress field of the area is left-lateral extensional shear. The reservoir formation model of Xin 183 accommodation zone is constructed, and the preferred hydrocarbon locations are pointed out. [Received: September 23, 2012; Accepted: July 12, 2013]