Abstract:
For the serious problems of pulverized coal production in some coalbed methane wells in Shizhuang Block in the south of Qinshui Basin, this study recognizes the coal structure of CBM wells in the study area by using the integrated identification method of the well-logging curve and the tectonic curvature, and analyzes the output characteristics of different CBM wells, such as the mass concentration, particle size, and morphology of the coal powder. It is found that the identification results of logging parameters and tectonic curvature are well matched, in the southern part of the study area, the structural curvature value is low, and the primary and cataclastic structural coal is the main one, while the structural curvature value near the fault development is high, and the cataclastic and mylonitic structural coal is the main one, there is a good correlation between the characteristics of coal powder and the coal body structure. The concentration of primary structural coal in Shizhuang south CBM well is 0.271 g/L, the mass concentration of fractured structural coal is 0.634 g/L, and the concentration of granulated-mylonitic structural coal is 4.872 g/L. The particle size of the output coal powder is mainly in the range of 1-100 μm; the pulverized coal with particle size of 1-10 μm gradually increases with the crushing of the coal structure, and the pulverized coal with particle size more than 1 000 μm gradually decreases. Under the influence of structure and drainage, the shape of pulverized coal gradually tends to be spherical and flaky aggregate.