Tectonic Evolution And Hydrocarbon Accumulation In Yang Shuiwu Buried Hill Belt Western Bohai Bay Basin

The Yang Shuiwu Buried Hill Belt is an important oil and gas-rich zone that has been discovered in recent years.In order to better serve the oil and gas exploration,it is necessary to conduct a detailed study on the period of formation,geological structure,tectonic evolution and the control role of tectonic evolution on oil and gas reservoirs in the buried hill belt.In this paper,high-precision 3D seismic data bodies and drilling data are used to develop the horizon calibration and seismic interpretation.Based on the interpretation of the strata and the recognition of the geological information on the seismic profile,the distribution range,geological structure,fracture development and tectonic evolution process of the buried hill are studied in detail.Combined with the related oil and gas development work,the control effect of the tectonic activity on the oil and gas in Yang Shuiwu buried hill belt is discussed.According to the findings of the study,the following conclusions are drawn:1.Five unconformities are identified in the Yang Shuiwu buried hill belt,including ?/Jx,C-P/O,Mz/C-P,E/C-P and N/E.Based on the development of the unconformities,six tectono-stratigraphy can be divided: basement tectono-stratigraphy,Meso-Neoproterozoic tectono-stratigraphy,Lower Paleozoic tectono-stratigraphy,Carboniferous-Permian tectono-stratigraphy,Mesozoic tectono-stratigraphy,Paleogene tectono-stratigraphy and Neogene-Quaternary tectono-stratigraphy.2.Through the interpretation of the seismic profile and the tracing of the overlay,it is found that the Yang Shuiwu buried hill belt on the footwall of He Xiwu fault is spreading in the north-north-east direction,and the Si Cundian buried hill belt on the hanging wall of the fault is spreading in the north-east direction,which is due to the control of the Daxing fault and Hexiwu fault.3.The Yang Shuiwu buried hill belt is an ancient buried hill formed in the Mesozoic,which was squeezed to form a near east-west direction anticline during the Indo-China movement.During the Yanshan movement.the buried hill is being squeezed in the northwest-southeast direction,the buried hill rotated,and uplifted to suffer erosion In the Himalayan movement,the Langgu Depression entered the rifting period.With the development of the He Xiwu fault,the ancient buried hill was divided into two parts,which were located on the hanging wall and footwall of the fault.The buried hill in the footwall were broken off into three buried hills that are now parallel and diagonal.4.The formation of oil and gas reservoirs in the Yang Shuiwu buried hill is closely related to the Indo-China and Yanshan movements.Indo-China movement and Yanshan movement deformed the folds and developed fissures in the strata,which was beneficial to the development of the reservoir.Subsequently,during the Himalayan period,the Langgu Depression entered the rifting period,bringing the Cenozoic hydrocarbon source rocks into contact with the Ordovician reservoirs,which was beneficial to oil and gas migration and reservoir formation.Tectonic activities control the formation and development of oil and gas reservoirs in the Yang Shuiwu buried hill belt.