AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Faults and Their Interaction in the Offshore Bohai Bay Basin: Implication for Hydrocarbon Exploration
(1) China University of Petroleum, Beijing, China.
Abstract: Faulting is an important factor controlling hydrocarbon accumulation in the offshore Bohai Bay Basin. Based on the seismic interpretation and structural mapping, the fault systems and their interaction and influence on hydrocarbon accumulation in the offshore Bohai Bay Basin are analyzed. The extensional and strike-slip faults are the most important in the study area, and inversion faults are locally distributed. In plane view, the trends of faults are the NE, NW and EW directions, and the NE-striking faults, which appear flower-structure features in seicmic profiles, belong to the Tanlu strike-slip fault, and the NW-trending faults are related with the Zhangjiakou-Penglai strike-slip fault. The EW-striking faults could be classified into the small- and large-scale faults, and the small-scale faults in the shallow strata were resulted from the strike-slipping movement of the Tanlu fault. The large-scale faults, which act as the boundary faults between the uplifts and depressions in the southern region, have quasi-flower structures composed of the major listric faults and branching strike-slip faults in seismic lines, and their formation should be controlled by the early S-N extension and the late strike-slipping movement of the Tanlu fault.
On the whole, the amount of the faults in the offshore Bohai Bay Basin is very numerous, and their shapes and strikes are obvious change. Then, the faults interaction in the study area is realtively complicated. In the basin scale, the NE- and NW-trending faults constitute the conjugate shear faults system during the neotectonic time. In addition, abundant small-scale examples of faults interaction, such as the X-pattern normal faults and transfer zones, are also developed well. The recent important breakthrough of hydrocarbon exploration has demonstrated that the faults interaction had exerted significance on the hydrocarbon accumulation, mostly through controlling the formation of traps, hydrocarbon migration, as well as improving reservoir properties.