高煤阶煤层气井煤粉产出对渗透率影响研究

高煤阶煤层气井在钻井、开采过程中由于机械碰撞、气液冲刷、压力波动等外力作用，不可避免的会产生煤粉，煤粉的产出一方面有利于形成气液产出通道，但另一方面如果过快、过多的产出使气水流动出现障碍，引起产气量下降，同时频繁的检泵作业导致气井的解吸一吸附过程交错进行，严重影响了气井的正常生产；本文通过煤粉产出与渗透率的关系、排采速度对煤粉产出的影响等室内模拟实验，论证了高煤阶煤层气井煤粉产出控制的重要性。

Study of the Impact of Coal Dust Yield on Permeability Rate in High Rank CBM Well

High rank of CBM well will inevitably produce coal dusts in the process of well boring, gas extraction due to external forces, like mechanical collision, gas and fluid flushing, fluctuation of pressure, etc. Occurrence of cuttings on one hand, is favorable to formation of passages for the yielded gas and fluid, one the other hand, too many dusts become obstacles to gas and water flow, resulting in drop of production, and alternate desorption and absorption due to frequent repair of pump. All these affected seriously normal operation of gas well. The paper discusses the importance of controlling formation of fine coal in high rank CBM well, by making laboratory tests to understand the relationship between yield of coal dusts and permeability rate as well as the influence of gas extraction rate on yield of coal fines, etc.