Coal seam fracture identification and drilling optimization design in Wangzhuang Coal Mine
In order to more efficiently and accurately identify the dominant orientation of coal seam fractures and promote the effect of gas drainage,the No.91-105 working faces of Wangzhuang Coal Mine was taken as the test object,using geological structural stress the-ory and Matlab software,and based on the three-dimensional fracture tensor theory,a quantitative analysis of the dominant orientation of coal seam fracture permeability and determination of the main seepage direction were carried out.The results show that there are two main strike directions of coal seam fractures in No.91-105 working faces of Wangzhuang Coal Mine,which are NEE and NW respective-ly.The dominant orientations of the working face towards fractures are mainly 134°,193°,and 241°.The theoretical calculation shows that the main seepage directions of the four geological units in the working face are 343.75°,62.14°,283.84°,and 40.84°,respective-ly,with permeability tensors of 0.238 6 × 10-7,0.350 3 × 10-7,0.122 6 × 10-7,0.168 7 × 10-7 μm2,respectively.After optimizing the drilling angle of the working face based on the judgment of the advantageous direction,the net extraction amount of a single drilling hole increased by 2.96 times,effectively improving the drilling extraction flow rate and concentration.The experimental results provide a drilling optimization design scheme for determining the preferred direction of permeability in coal seam extraction boreholes.
万方数据
维普
