地层水对不同粒径煤岩解吸-扩散影响的实验研究

利用自主研发的入井液煤岩解吸实验装置,测试了四种粒径的干煤样和地层水注入后的解吸规律实验研究。通过逐渐降低解吸压力,研究注水前后不同粒径煤样在不同压力段下的解吸百分比变化。实验结果表明,无论是否注水,煤样粒径越小,解吸量越大。在注水后,粒径越大,解吸量伤害程度越高。根据煤层气的运移机理和煤样结构分析,将不同粒径煤样分为两种尺度的煤样。对于同一尺度下的干煤样,粒径越小,在压力降落初期越容易解吸;注水后,粒径越小,在压力降落初期受到的影响越大。

Experimental study on different particle size coalbed methanedesorption-diffusion Influenced by formation water Injection

Independently developed CBM desorption experimental apparatus was used to test four kinds of particle size of coal samples desorption rules. Research of different particle size of coal samples under different pressure section of desorption percentage change were studied by gradually reducing desorption pressure. The experimental results show that, regardless of the water injection, the smaller the particle size of coal samples, the larger the desorption amount. After water injection, the particle size greater, the desorption amount of damage degree is higher. According to analysis of coalbed methane migration mechanism and the structure of coal sample, different size of coal sample can be divided into two dimensions of coal samples. For dry coal samples under the same scale, the smaller the particle size, the easier desorption at the beginning of the pressure to land; After water injection, the smaller the particle size, at the beginning of the pressure to land the greater impact.