Study On The Characteristics Of Fracture Structure And Its Relationship With Oil And Gas Distribution In Lixian Slope,Jizhong Depression

Multi-strike faults such as NW,NNW,NEE and NE are widely developed on the Li Xian slope,among which NNW and NW-oriented faults control the stratigraphic morphology in the basement period,and a series of NE and NEE-oriented faults in the eastern part of the slope control the Cenozoic slope evolution.Based on the characteristics of the fracture geometry of the Li Xian slope in the Rao Yang Depression of the Jizhong Depression.This thesis determines the different activity periods of different strike-to-fault faults,and the results show that the NW and NNW faults were formed in the basement period,the Cenozoic stopped developing to form the basement cryptic faults,and the Maxi fault was active for a long time.T he NEE and NE faults were widely formed in all periods of the Cenozoic rifting.Among them,NW formed in the basement period,the basement fault of NNW controls the early slope prototype,with the stress transformation to NW-oriented,and then the NE-oriented fault formed for the late slope control fault,the rest of the NEE-oriented fault for the late formation of the fault,and the Li Xian slope fracture deformation has experienced three evolutionary stages:1.Rift trapⅠc urtain deformation stage of Ek+Es₄;2.the rift trapⅡc urtain deformation stage of Es₃+Es₂;3.the rift trapⅢc urtain deformation stage of the Es₁+Ed.After determining the activity period of the fault and deformation nature of the fault,the fault c an b e d ivided i nto f our s ets o f f ault s ystems b ased o n t he"three p hases a nd t hree properties"of the fault in the study area:1.Basement-initiated faults including basement-hosted faults a nd l ong-term a ctive f aults（Maxi f ault）;2.R ift tr apⅠc urtain i nitiation f ault,t he N E-directional faults formed in this period are the main slope control faults;3.Rift trapⅡc urtain initiation fault;4.Rift trapⅢc urtain initiation fault.After clarifying the fracture tectonic features on the slope,the research on the relationship between f racture f eatures a nd o il a nd g as d istribution is d ivided i nto t wo a spects:1.T he influence of fracture on trap formation,（1）f ault activity controls the formation of traps in the nose-like tectonic zone;（2）the segmental growth of faults controls the formation of traps,and traps are formed between the segmental points of the reverse positive fault,the lower plate of the Gaoyang fault,located at the boundary of the middle and outer zones;2.The influence of fracture on oil and gas transport,（1）the role of oil and gas in the process of vertical transport,combined w ith t he l ocation o f h ydrocarbon s ource r ock d evelopment a nd t he a ctivity o f t he fault,fr acture c ontrols t he v ertical tr ansport o f o il a nd g as;（2）f ault-cap d eformation h as a controlling effect on the vertical transport of oil and gas.