煤层气为自生自储型非常规天然气资源。为了更好地开发煤层气，需要深入研究煤层气的开采机 理。煤层气赋存于煤岩层的割理和基质孔隙中，以吸附状态为主，且与地层水共存。煤层气从孔隙壁面上 解吸下来之后，才能被开采。开采地层水导致地层压力下降，进而导致煤层气解吸成为自由气，解吸后的 煤层气沿割理渗流至井底后被采出地面。煤层气的开采过程包括脱气、解吸和渗流3 个阶段。扩散不是 煤层气的开采机理。

Coalbed methane is an unconventional natural gas resource of self-generating and self-preserving. In order to develop the gas properly, it is necessary to study deeply the flowmechanismof coalbed methane. Coalbed methane is stored in the cheats of coalbed and pores of coal matrix, which is in the form of adsorption and coexists with formation water in coals. Coalbed methane must be desorbed from the pore wall before developed. Production of water from coalbed results in the drop of pressure, which leads to the desorption of coalbed methane to free gas. The coalbed methane desorbed flows to well bottomalong cheats in coals and then is developed to ground surface. The development of coalbed methane can be divided into three stages: degassing, desorption and flowing. Diffusion is not a part of flow mechanismof coalbed methane.