煤层气储层煤粉运移规律试验研究

Experimental Research of Coal Grain Migration Rules of Coalbed Methane

在研究煤粉形成及运移规律的基础上,通过室内人造裂缝的方法,开展了不同粒径的煤粉在不同裂缝宽度、不同流动速度下的运移规律试验,研究了裂缝宽度、流动速度、煤粉粒径与出粉量、渗透率的关系,对制定生产中煤粉控制措施具有重要的指导意义。研究结果表明,随着流量的增大,煤心出口端煤粉含量增多,煤岩的渗透率下降,渗透率伤害率升高;在排水的初始阶段,在相同裂缝宽度、相同颗粒直径下,随着排水体积的增加,渗透率伤害率非常大,但是排出一定体积之后再继续排水,渗透率下降速度减慢。

A laboratory experiment was performed on migration laws of coal dust of different grain sizes in different fracture widths with different flow velocities on the bases of studying coal grain formation and migration.The relation among coal-dust quantity,fracture width,flow velocity,grain size and permeability was studied,which was important for establishing the controlling measures of coal grain.The results indicate that the higher flow rate is,the more quantity of coal grain is and the higher permeability damage is,at the initial stage of drainage,with the increase of injection volume,permeability damage rate is very high in the same fracture width and grain size,but the permeability damage ratio become slowly,even if fluid is injected,after a certain volume of drainage.