The Study Of Fluidl-Solid Coupling Theory Of Coalbed Methane In Low Permeabiliyt Reservoir

Coal-bed gas is a sort of nature gas which lies in coal-bed and appears in the course of forming of the coal. Coal-bed gas is harmful to safety production in mining, and makes a lot of giant accidents. It is considered that the gas pre-drainage measure in coal seam is one of the most effective method to prevent the gas disaster. With the depth of coal seam increase, the permeability decrease. Consequently it affects the drainage rate and efficiency. So it becomes the key link solving the gas drainage in low-permeable coal seams to insure in coal mine security and enhance production efficiency. With the development of society economy and the requirement aggrandizement for energy sources, the gas source exploitation and its using become more and more attention. So it has important society value and economy efficiency to have the research of fluid-solid coupling in low-permeability coal seams.In this paper, the storage characteristic of the coal seam and mechanical properties of gas-filled coal is introduced firstly, as offers the basis of the study of physical parameter and effective stress of coal and the foundation of the mathematical model of fluid-solid coupling of coal-bed gas.In addition, the fluid-solid coupling model which related to the seepage course in low permeable dual-porous medium is founded by analyzing the law of seepage of gas and water which flow in coal and considering the effect of threshold pressure gradient. Finally, the mathematical model of fluid-solid coupling is solved with the finite difference method and the finite element method. And the program of simulation of fluid-solid coupling of coal-bed gas and gas seepage is worked out by the computer language C on the condition of laneway drill, and the simulation results of two kinds of models is compared and analyzed.