Study On The Influence Of Structural Deformation Characteristics Of Wujiang Fault Zone On Shale Gas Reservoirs Area Of Fuling

Wujiang fault zone is located in Fuling area.It is a fault anticline zone with multiple structural properties.This paper studies the structural deformation characteristics and the influence of shale gas reservoir preservation in the study area,which has important theoretical significance and practical value for further expanding resource positions and guiding the production and construction development of complex structural development zones.Based on the results of fine interpretation of seismic structure,this paper divides four sets of tectonic deformed layers by analyzing the distribution of regional basement structure and decollement layer,and considering the influence of deep and shallow decollement surface.Two structural types and eight basic structural styles related to compression and strike-slip(compression-torsion)are identified.Due to the combination and superposition of the surrounding structural belts,the structural types and styles of each section are different.It is pointed out that the study area has a variety of characteristics of base-involved thrust,sinistral compression torsion and cap slip in the middle and deep layers.A total of 9 structural combinations of each section are summarized.According to the principle of structural unit division,the research can be divided into three five-level structural units.The tectonic deformation in Fuling area can be divided into three stages.It is pointed out that Wujiang fault formed in the third stage of the middle Yanshan.The key indicators affecting the preservation conditions of shale gas reservoirs were analyzed from the macroscopic and microscopic perspectives :(1)Through the analysis of the structural style characteristics of the main deformation area,it was concluded that the destruction of the target layer was concentrated in the front end,the gas content of the target layer in the back edge was better than that in the front end,and the north section was wide and slow faulted anticline and slope,so the preservation effect of shale gas was better.(2)According to the analysis of ant body,curvature attribute and drilling technology,the main fracture types in the study area were determined.The structural deformation analysis of Wells JY5,JY50-5HF and JY9 revealed that fractures and fractures developed in the south section,the target zone was thrust,and the shale gas escaped strongly.Shallow slippage in the middle section forms bedding shear fractures and collapse,resulting in shale gas loss.There are relatively few faults in the north section,and bedding fractures are developed,which is conducive to the flow of shale gas.(3)From the microscopic index of shale segment-several parameter values of gas reservoir geological characteristics(burial depth and pressure,porosity,total hydrocarbon display),the No.1 >,No.2 > and No.3 anticlinal zone indicates that the shale gas preservation effect in the northern segment is good.In the front of the main deformation zone of Wujiang fault zone,there are certain risks in shale gas exploration due to broken fault blocks.On the basis of shale fractures,bedding shear fractures are developed in the gentle area at the back edge of fault anticline,which can improve the transverse porosity and permeability,especially in the northern fault slip fold back and Jiaoshiba anticline slope area with great exploration potential.