The Characteristeristics Of Ioint Development And The Prediction Of 2# Coal Bed Methane In The Gujiao Area Of Xishan Coalfield

In xishan coalfield gujiao area as the study area,the research area of rock joints and coal seam cracks conducting field investigation and sorting,has counted more than 3700 development in different rock joint,the geometry,the occurrence of the joint,the density of filling mechanism,the distribution and controlling factors has made the detailed geological analysis,has made the forecast in the favorable exploration area of 2 # coal bed methane,late for coal-bed methane in this area provides an important reference value and theory.Some 48 system observation point conjugate joints,staging,restore the old block of four stage of tectonic stress field since Mesozoic,indo-chinese epoch of SN to extrusion stress,the middle-late yanshan movement in the NW NWW-to the extrusion stress,the Himalayan period NNE to NE to the extrusion stress,the neotectonic period NW to NNW to pull a tensile stress.On the basis of this,the tectonic evolution of the ancient intersection,the malan syncline and the tectonic deformation of the fault zone are explained.Through field investigation and corresponding rosette drawing,the research area is oriented towards the near EW direction and NE direction withthe main advantages of the shear joints in the development of high inclination layer,and the filling mechanism is dominated by the mud filling.Analysis of joint development pattern and density,the use of two control factors is the same,one-way analysis of factor influence on joint development,capable of rock,the greater the shear strength,the greater the joint spacing is larger;When the thickness of rock strata is less than 20 cm,it has a great influence on the joint density.When the thickness of the strata is greater than 1m ~ 1.5m,the development density of the joints tends to be stable.The statistical function of the joint density of the observation points in different parts of the maran and the ancient cross fault shows that the farther from the tectonic belt,the smaller the joint development density is.The single axial deformation test and triaxial crushing test were carried out for sandstone samples and 2# coal samples collected in the research area.In addition,the internal friction Angle is relatively small,so the shear strength of2# coal is relatively small,and the crack growth is relatively dense,which increases the permeability of coalbed methane.Based on the correlation analysis of rock formation joint and coal seam fissure,the fracture development density of 2# coal in buried depth was predicted by taking parameter method,The geological factors such as drilling data data and stress state environmental fracture distribution density are analyzed comprehensively,and the coal bed methane mining area with high commercial value is preliminarily forecasted.