本文结合某煤层气区块内BI井的实际排采资料,应用煤储层岩石学和渗流力学理论,分析了排采制度对煤粉运移的影响,认为影响原因包括储层粘土矿物的含量、流体渗流速度、孔隙结构变形和割理闭合、气水两相流等;并建议在煤层气井的排采过程中,应做到缓慢、稳定、连续,延缓气水两相流的出现时间,尽量在临界解析压力之上扩大解析半径,避免因渗流速度过快而导致煤粉运移、孔隙结构变形和割理闭合,最终实现煤层气的大面积解析和产出。
In this paper, B1 coalbed methane well was applied as a case to analyze the relationship be- tween drainage process and fines migration. With the application of coal petrology and fluid mechanics in porous media, this study concluded that factors such as clay mineral content, witer velocity, grain pores deformation and cleats close, and gas - water two - phase flow made contribution to the plugging of the flow paths during dewatering gas production. In order to minimize fines damage and maximize production, the drainage process should be slow, stable and continuous; and the bottom hole pressure should be con- trolled above the critical desorption pressure for some time to delay the occurrence of gas - water two - phase flow, thereby promoting the propagation of the depression cone and increasing the desorption area.