Mesozoic-Paleozoic Tectonic Deformation Effect On The Influenced Research Of Shale Gas Enrichment Geological Factors In Jiao Shiba Region

In this paper,making full use of the 3D seismic data,guided by tectonic geometry,kinematics and dynamics,the basic rules of balanced section are applied in restoring the tectonic evolution of the study area,the tectonic types,correlarion and disributions of the Mesozoic-Palaeozoic basement detachment?decollement?nappe? thrust and cover-decollement?thrust have been analyzed in system,established characteristics of fracture structure,typical structural patterns and modles,confirmed the tectonic evolution stages and formation mechanism,through tectonic deformation mechanism,the relationship between tectonic deformation effect and fracture prediction,tectonic deformation control effect on the influenced research of shale gas enrichment has been analyzed emphatically.In the tectonic analysis of Mesozoic-Palaeozoic,based on the integrated interpretation of seismic geologic profile and through-well seismic section,established Mesozoic-Palaeozoic tectonic framework of Jiao Shiba as well as east of Sichuan area,it revealed the main characteristics of tectonic property,tectonic type,tectonic style of the Mesozoic-Palaeozoic base-involved tectonic and cover-decollement thrust fold tectonic.The study area has rich transformation type tectonic assemblages of cover-decollement(thin skin)which is dominated by three groups imbricated obduction-thrust-overthrust of base-involved(thick thin);summarized two kinds of tectonic assemblages types and 13 kinds of tectonic assemblages styles and 10 kinds of basic tectonic styles;established the six typical kinds of the decollement kinematic model.The study area has experienced three periods and five stages of tectonic deformation and retrofit process,the main tectonic deformation stage is early and middle Yanshanian,the formative period of Jura-type of comb-like folds,medium and shallow crustal detachment and base-involved imbricated thrust laid the study area basic tectonic framework.By tectonic deformation,formation mechanism and the mutual relation of fissure prediction and tectonic deformation,established accumulation model of this distict,considering the structure plays a crucial role in the control of shale gas,and evaluated the preservation condition.Thinking Jura-type of comb-like folds has produced wide slow syncline,the middle Yanshanian imbricated thrust-back thrust has produced wide slow ancline and provided excellent tectonic background conditions,wide slow ancline and faulted anticline have benefit in looking for shale gas field(hide);the background of wide slow ancline,the slope faulted anticline and syncline of the positive tectonic flexural slip effect was easy to form bedding shear joints,on the basis of shale bedding sewing has an effect on improving horizontal porosity and permeability;the strong feformation of this area produces slip type structure,especially Longmaxi-Wufeng Group strong detachment area,the overlying region of generating faults has bad benifit in shale gas accumulation;slow deformation zone is the unconventional accumulation area,strong deformation zone is the conventional accumulation area.