The Tectonic Characteristics And Hydrocarbon Accumulation Of Kendong Uplift And Adjacent Region

Kendong Uplift is a subsidiary uplift of the southern Bohai Bay basin. There are four sags adjoining the uplift and hydrocarbon is rich, so the uplift and adjacent region is an important target area of Bohai Bay basin. The tectonic style of Kendong Uplift and adjacent region is complex, including all kinds of faults and fault-block associations which are controlled by extensional tectonic system, shear tectonic system, and reversal tectonic system.In order to study the tectonic characteristics and hydrocarbon accumulation rules of Kendong uplift, Qingdong sag and adjacent region, and look for advantaged traps, based on the exploring practice and research of geology, the study utilizes the theories and methods about extensional structure, recovers the tectonic evolution history of Kendong Uplift and adjacent region, analyzes structural geometry and kinematics characteristics, discusses all kinds of structure styles, summarizes the trap types, and brings forward exploring targets. Seven results are gained from the study on the geology, geophysics, and geochemistry of Kendong Uplift and adjacent region:1. The tectonic evolution history shows that Kendong Uplift and adjacent region experienced three stages: Pre-rift Period, Rifting Period, and Post-rift Period. So the stratum shows three-layer structure in architecture.2. For the existence of the extensional rift, uplift and transverse accommodation zone joined the rift and uplift, the regional structure of the Kendong Uplift and adjacent region can be divided into several belts and sections on the SN and EW direction. Among the five transverse accommodation zones, the third and forth the transverse accommodation zone control the tectonic pattern of the Kendong Uplift and adjacent region.3. Based on the calculating of the extensional coefficient, fault growing index, subsidence rate, and fault throw, the study analyzes the fault block movement types of Kendong Uplift and adjacent region: extensional movement, rotational movement and differential uplift and depression. The characteristic of the region structural evolution movement was strengthen in the early stage of rift Period and gradually weakened in the late rift Period and Post-rift Period are concluded. 4. The tectonic style of Kendong uplift, Qingdong sag and adjacent region can be divided three systems: extensional system, shear system, and reversal system, which including nine style.5. The hydrocarbon trap of Kendong Uplift, Qingdong sag and adjacent region can be divided five types: structure trap, lithologic trap, stratigraphic trap, and combination trap, which including fifteen subtypes.6. The hydrocarbon of Kendong Uplift and adjacent region mainly come from the source center of Palogene Huanghekou extensional rift. By stair-stepping broadside and lengthways pathway formed by unconformity surface, sand bodies, and normal faults, hydrocarbon migrates to Kendong Uplift from north to south, and accumulates in advantaged traps of the Palogene and Neogene stratum.7. Fault is one of the main controlling factors of hydrocarbon formation, migration, accumulation, and distribution in Kendong uplift, Qingdong sag and other adjacent region; reservoir and cap rock influence the hydrocarbon concentration and distribution; unconformity surface controls the distribution of lithologic reservoir and stratigraphic reservoir in Qingdong sag.