The Relationship Between The Difference Of Superimposed Strike Slip Fault System And The Occurrence Of Oil And Gasin Depression Of Huanghekou To Miaoxi

This paper is based on regional geology,drilling and seismic data,taking the fracture evolution as the main line,combined with the previous research results,this paper analyzes in detail the plane distribution characteristics,profile combination patterns,multi-stage evolution process and activity of the main faults in the east depression of Huanghekou to the south depression of Miaoxi,and further discusses the control effect of the superimposed strike slip fault system on the occurrence of oil and gas The spatial-temporal distribution of hydrocarbon source distribution,trap type and oil-gas migration are analyzed.The following major achievements have been achieved:The extensional strike slip fault system in the study area controls the regional structural pattern,and mainly develops three types of structural patterns: extensional,strike slip and superimposed strike slip.According to the distribution characteristics of the fault combination pattern,it is found that the extensional fault plane is nearly EW oriented,and the profile is mainly shovel and plate shaped,with four combination patterns of "Y" type,anti "Y" type,cabbage type and flower like;the East branch The plane of strike slip fault is NNE oriented,which is the boundary fault between the east depression of Huanghekou and the southwest depression of Miaoxian.The whole section is high angle plate or vertical fault,and the shallow part is developed with negative flower and half flower structure,with obvious ribbon effect and dolphin effect.The superimposed strike slip fault system is mainly developed in the superimposed area of the East Branch strike slip fault belt,and the section is mainly characterized by the middle part of the extension main fault slope Strike slip faults are cut and shallow layers are superimposed to form multi-level "y" shape and negative flower structure style.The main faults in the study area have experienced four stages of activity evolution: the fourth member of Kongdian to Shahejie formation is in the period of strong fault depression,and the EW oriented extensional faults in the depression are obvious,such as laibei No.2,Bonan No.1 and Miaoxi No.2 faults,which control the deposition of the east and southwest Huanghekou depressions;the third member of Shahejie formation is in the period of fault inheritance and extension,and the extensional activities of the faults are the strongest;the third member of Shahejie formation is in the period of fault inheritance and extension The sedimentary period of the second member of Hejie formation Dongying Formation is strong strike slip weak extension period,the fault extension activity is gradually weakened,the strike slip action is strengthened,and the shallow secondary faults begin to develop;the sedimentary period of Guantao Formation to Minghuazhen Formation is strong strike slip period,the flower structure is obviously developed,the secondary faults are widely developed,and they form a variety of structural styles with the main faults.At the same time,combined with the quantitative evaluation of fault activity rate,it is clear that the peak period of extensional fault activity is the sedimentary period of the third member of Shahejie formation,in which the maximum activity rate of laibei No.2 fault can reach 112 m / Ma.The study shows that the scale of extensional fault controls the deposition of source rock,the pattern of fault combination controls the type of trap,and the activity of fault controls the migration of oil and gas.On this basis,the relationship between the three types of fault systems and the occurrence of oil and gas is studied.It is considered that the oil and gas accumulation in the east depression of the Huanghekou has the characteristics of "hydrocarbon generation of two main source rocks,controlled migration by faults and reservoir formation in the near source and late stage";the oil and gas accumulation in the south depression of the Miaoxi has the characteristics of "hydrocarbon source rocks are rich in the north and poor in the south,controlled by faults and migrated to reservoir near source" Features.