应力-地层水作用下煤层气解吸特征实验研究

Experimental Study on CBM Desorption Characteristics under Joint Action of Geostress-formation Water

利用自主研制的煤岩解吸分析实验装置,分析煤样在地应力-地层水作用下煤层气的解吸规律。通过测试煤岩在地应力和地层水单独或复合作用下的解吸特征,实时监测了解吸量与解吸时间、解吸压力的关系。对比了不同解吸条件下的解吸恢复率。研究表明,四种解吸条件下的解吸恢复率排序为:自然条件下>地层水作用>地应力作用>地应力和地层水共同作用;在地应力和地层水共同作用下解吸量约为自然解吸条件下解吸量的25.3%,自然条件下平均解吸速率为地应力和地层水共同作用下平均解吸速率的3.6倍。

Using independently developed CBM desorption experimental apparatus, the paper analyzes the rule of CBM desorption under the separated or joint action of geostress and formation water action. Through testing the CBM desorption characteristics under geostress and formation water, it conducts real- time monitoring of the relationship of the amount of desorption with desorption time and desorption pres- sure, and compares the recovery rate of desorption with different desorption conditions. Research shows that, under the four desorption conditions, the desorption recovery rate order is natural conditions 〉 for- mation water 〉 geostress 〉 joint action of geostress and formation water. The amount of desorption un- der the joint action of geostress and formation water is about 25.3% of the amount of natural desorption. The average desorption rate with natural conditions is 3.6 times of the rate under the joint action of geostress and formation water.