【摘要】 针对常规直井煤层气开采过程中的煤层泄压解吸面积低、压裂增产规模有限、压裂液对煤储层存在不同程度的损伤、抽采效率低等问题,结合柳林地区地质特征,提出了双煤层多分支水平井煤层气开采方式。分析了多分支水平井增产原理,认为通过增大煤层解吸暴露面积,提高气体导流能力,促进微裂缝动态发育,增加煤层气运移通道等方式,可以提高煤层气抽采效率。在柳林地区开展了工程应用,结果表明:与常规直井相比,通过双煤层多分支煤层气开采技术应用,研究区最高日产气量提高了5.18～9.0倍,日均产气量提高了6.27～10.19倍。更多还原

【Abstract】 Aiming at the problems during conventional vertical well CBM exploitation, such as small area of coal seam pressure relief and desorption, limited scale of fracturing stimulation, different damage degree of fracturing fluid into coal reservoir, resulting in low extraction efficiency, combined with the geological characteristics of Liulin area, this paper put forward the method of CBM exploitation with double coal seams and multi-branch horizontal wells.This paper analyzed the stimulation principle of multi-branch horizontal wells, it was considered that the extraction efficiency can be improved by increasing the exposed area of coal seam desorption, improving gas conductivity, developing dynamic micro-fractures, and increasing the migration channel of CBM.The engineering application had been carried out in Liulin area.The results showed that the maximum daily gas production in the study area was increased by 5.18～9.0 times and the average daily gas production was increased by 6.27～10.19 times compared with the conventional vertical wells through the application of CBM mining technology in multi-branch horizontal wells with double coal seams, which effectively improved the extraction efficiency of CBM.更多还原