Abstract:

Kendong Uplift is a new hydrocarbon exploration field in central and southern Bohai Bay Basin. In order to study the tectonic characteristics and hydrocarbon accumulation rules of Kendong Uplift, and look for advantaged traps, the following topics are discussed in this paper:the tectonic characteristics of central and southern Bohai Bay Basin，the tectonic evolution history and structural style of Kendong Uplift,and the types of traps and the characteristics of hydrocarbon accumulation.Some conclusions were drawn from the study on the geology, geophysics, and geochemistry of Kendong Uplift.The existence of the extensional-depressions fault uplifts and transverse accommodation zone which joined them shows that the regional structure of the central and southern Bohai Bay Basin can be divided into several belts and sections on the SN and EW direction in plane.The tectonic evolution history shows that Kendong Uplift and northern slope zone experienced three stages: Pre-rift Period, Rifting Period, and Post-rift Period.Therefore, the stratum shows three-layer architectures in profile.Kendong Uplift can be divided into west high uplift and east lower uplift, bordering respectively upon west part and east part of northern slope zone. The structural style of northern slope zone is mainly stair-stepping normal faults with some dip; but in the uplift, the structural style is mainly horst combined by two major normal faults with opposed dip and graben combined by two major normal faults in which one fault situated  face to face with another fault.The traps of Kendong Uplift can be divided into five types,among which dragging anticline, reverse dragging anticline, roof-shaped fault block, and drape anticline are structural traps.The hydrocarbon mainly comes from the source center of Palogene Huanghekou extensional fault depression. Along vertical and lateral migrating pathways formed by unconformity surface, sand bodies, and stair-stepping normal faults, hydrocarbon migrated to Kendong Uplift and northern slope zone from north to south, and accumulated in favorable traps of the Palogene and Neogene strata.

Key words: tectonic evolution, tectonic characteristic, hydrocarbon trap, hydrocarbon accumulation, Kendong Uplift