The Fault Features Of Liaodong Bay In Bohai Sea And Relation With Hydrocarbon Accumulations

Liaodong Bay Area located in the northen of Bohai Bay Basin,Tanlu fault zonethrongh this area,established the basic tectonic framework of "three concave and twoconvex ".The formation of faults in Liaodong Bay area is mainly affected by the early thirdcentury North West—souch east direction extensional activities and late third century ofright direction slip activity. Structures of different period interpenetrated, superposed,transformed, finally formed extensional fracture and strike slip tectonic; and formed variousstructural traps, such as semi anticline, fault block, fault nose, fault anticline and ancientQianshan trap.Many scholars have made systematic research on the faults in Liaodong Bay area, andthe achievement is significant, but they did not reach a consensus on some issues. The mainproblems are: the fracture style and its distribution in Liaodong Bay area? The evolutionstages and formation mechanism of different types faults? Oil and gas accumulation styleand the differences of various faults? How does the structural transfer zone control the oiland gas accumulation? The above problems should be further studied. This paper is aimedat these problems, using seismic data and well logging data interpretation, balancedcross-section restoration, structural style analysis and other methods, analyses the formationand distribution of various fault pattern through several angles,such as geometry,kinematics, dynamics,to research how the fracture effect the accumulation of oil and gas. Atthe same time analyze the accumulation model of oil and gas reservoirs, in order to provideguidance for exploration.Study shows: different types of fracture and their tectonic styles in Liaodong Bay areaare distributed in different time and space, their formation mechanism is different, closelyrelated to the evolution process. Faults not only control the trap, the sedimentary systemsdevelopment, but also on the oil and gas migration and accumulation. Fracturefundamentally control oil and gas accumulation in the area.