CBM recovery technology characterized by docking ground multi-branch horizontal wells with underground boreholes. Issue 6 (19th March 2021) - Mu, Yongliang
ABSTRACT: Although ground multi-branch horizontal wells can maximally connect the fractures in a coal reservoir and greatly increase the single well yield, this type of well is not appropriate in many mining areas in China, since conventional drainage and recovery must be carried out on the ground. In this work, a new coalbed methane (CBM) recovery technology is proposed, which is characterized by docking ground multi-branch horizontal wells with underground boreholes. In addition, three specific docking schemes are also given. In order to improve the efficiency of CBM recovery and avoid the huge investment of purchasing ground drainage and recovery equipment in LiuLin Block, an engineering test for connecting ground multi-branch horizontal wells with underground boreholes was carried out at the 24307 working face of the Shaqu coal mine. The engineering practice has proven that the CBM recovery technology characterized by docking ground multi-branch horizontal wells with underground boreholes captures CBM more efficiently than conventional underground CBM recovery, and it enables underground drainage and recovery when compared to conventional ground CBM recovery, thus avoiding the huge investment in purchasing ground drainage and recovery equipment, and increasing economic efficiency as well as improving the applicability of horizontal multi-branch horizontal wells.