Theoretical analysis and engineering application of controllable shock wave technology for enhancing coalbed methane in soft and low‑permeability coal seams  

作　　者：Guodong Qiao Zegong Liu Yongmin Zhang Changping Yi Kui Gao Shigui Fu Youzhi Zhao 

机构地区：[1]School of Safety Science and Engineering,Anhui University of Science and Technology,Huainan 232001,Anhui,China [2]Institute of Energy,Hefei Comprehensive National Science Center,Hefei 230031,Anhui,China [3]School of Electrical Engineering,Xi’an Jiaotong University,Xi’an 710049,Shanxi,China [4]Division of Mining and Geotechnical Engineering,LuleåUniversity of Technology,Luleå,Sweden

出　　处：《International Journal of Coal Science & Technology》2024年第2期123-142,共20页国际煤炭科学技术学报（英文）

基　　金：supported by the National Natural Science Foundation of China(52074013,52374179);China Huaneng Group Science and Technology Project(HNKJ20-H87);Natural Science Foundation of Anhui Province(2208085ME125);Hefei Comprehensive National Science Center(21KZS216),which are gratefully appreciated.

摘　　要：Coalbed methane(CBM)is a significant factor in triggering coal and gas outburst disaster,while also serving as a clean fuel.With the increasing depth of mining operations,coal seams that exhibit high levels of gas content and low permeability have become increasingly prevalent.While controllable shockwave(CSW)technology has proven effective in enhancing CBM in laboratory settings,there is a lack of reports on its field applications in soft and low-permeability coal seams.This study establishes the governing equations for stress waves induced by CSW.Laplace numerical inversion was employed to analyse the dynamic response of the coal seam during CSW antireflection.Additionally,quantitative calculations were performed for the crushed zone,fracture zone,and effective CSW influence range,which guided the selection of field test parameters.The results of the field test unveiled a substantial improvement in the gas permeability coefficient,the average rate of pure methane flowrate,and the mean gas flowrate within a 10 m radius of the antireflection borehole.These enhancements were notable,showing increases of 3 times,13.72 times,and 11.48 times,respectively.Furthermore,the field test performed on the CSW antireflection gas extraction hole cluster demonstrated a noticeable improvement in CBM extraction.After antireflection,the maximum peak gas concentration and maximum peak pure methane flow reached 71.2%and 2.59 m^(3)/min,respectively.These findings will offer valuable guidance for the application of CSW antireflection technology in soft and low-permeability coal seams.

关 键 词：CSW antireflection in coal seams CBM extraction enhancement Soft and low-permeability coal seams Field test 

分 类 号：P61[天文地球—矿床学]