Analysis Of Micropore Fissure And Seepage Characteristics Of Shale

Shale gas is a typical natural gas reservoir with continuous distribution of natural gas reservoir.It is mainly composed of adsorption state and free state.Directly affect the reservoir,migration and seepage of shale and other activities,Therefore,further research on Shale microporosity is of great significance for exploration and exploitation of shale gas.In this paper,the tectonic characteristics and the influence of regional tectonic evolution are summarized,The characteristics of pore fissure development in the shale of cattle hoof group were analyzed by scanning electron microscope experiment,low temperature liquid nitrogen adsorption experiment and high pressure mercury experiment,The change of shale permeability under different pressure and different stress is analyzed by three-axis seepage experiment.Discusses the influence factors of shale pore fissure and the influence of porosity,fracture permeability of shale.The research area of this paper has the development of north east,north and south,and the formation time of the north east to the north.From the structural point of view,it is affected by the east-west extrusion,and the early yanshan has formed the near north-south fold and the compression fault.In the later period,the stress changes to the east direction of the north and southwest,and the corresponding folds and faults are also formed.The structure of the north-south direction is also changed,and the plane is from northwest to southeast.The layout of the sedimentary environment of the cattle hoofang formation is general y the transition from subfacies of shal ow water to deep water shelf subfacies.Through the investigation of the field geology and the observation of the core,the macroscopic fracture morphology and development characteristics of shale are analyzed.The types of pore development of shale samples were analyzed by scanning electron microscopy(SEM),and the main types of pore growth were intergranular pores,granular pores,organic pore and microfractures.Combined with low temperature liquid nitrogen adsorption experiment and high pressure mercury injection experiment concluded that the micro pore specific surface area,pore size distribution,fractal characteristics of pore structure and other important parameters,shows that the charging bull pond group of shale pore structure complexity,strong heterogeneity,high specific surface area of the microporous contributed mainly.Using a three-axis seepage experiment to determine the change in shale permeability in different stresses analyze the control factors of shale permeability,It indicates that the growth of the pore structure is conducive to the migration of the shale.By changing the stress of the shale,the shale's pore structure parameters can also be changed to provide shale permeability,to increase the pore permeability of shale reservoir so as to increase shale permeability.