Applicability Evaluation of Coal-bed Methane Extraction Technology by Ground Well in Coal Mining Area

In the drilling process of the ground well, the objective conditions of the coal mining area are often uncertain due to the inadequate preparation, which may result in the well-body damage or undesirable coal-bed methane (CBM) capacity. In order to solve this problem, deep analysis was made on the factors affecting the applicability of the coal-bed methane extraction technology by ground wells in the coal mining area, it was concluded that the main affecting factors included the recoverable coal-bed methane resources (the thickness of coal seams, gas-bearing area and gas reserves), the hydro- geological conditions (the hydrodynamic condition and geological structure), the well stability (the coal structure, ground stress and chemical factors) and the topography and landform characters. An evaluation index system for the applicability of the coal-bed methane extraction technology by ground wells was set up based on the analytic hierarchy process and comprehensive fuzzy criterion, and by taking Sihe Coal Mine as an example, the judgment was carried out on the main factors affecting the applicability of the coal-bed methane extraction technology by ground wells, and its reliability was verified by this example. The study achievement provided the reference for researching the applicability of the combined coal-bed methane extraction technology by both ground wells and underground boreholes.