松软低渗突出煤层定向水力压裂增透消突实践  

Practice of Directional Hydraulic Fracturing in Soft and Low-Permeability Coal Seam for Permeability Enhancement and Outburst Elimination

作　　者：王晓强 樊世星 WANG Xiaoqiang;FAN Shixing(Department of Resources and Safety Engineering,Shanxi Engineering Vocational College,Taiyuan,Shanxi 030009,China;School of Safety Science and Engineering,Xi'an University of Science and Technology,Xi'an,Shaanxi 710054,China;Key Laboratory of Western Mine Exploitation and Hazard Prevention of Ministry of Education,Xi'an,Shaanxi 71o054,China)

机构地区：[1]山西工程职业学院资源与安全工程系,山西太原030009 [2]西安科技大学安全科学与工程学院,陕西西安710054 [3]教育部西部矿井开采及灾害防治重点实验室,陕西西安710054

出　　处：《矿业研究与开发》2024年第4期123-129,共7页Mining Research and Development

基　　金：国家自然科学基金资助项目(52104221)。

摘　　要：针对松软低渗突出煤层瓦斯含量大、难抽采,石门揭煤过程中易发生突出等问题,研究了定向水力压裂增透消突技术。首先,阐明了定向水力压裂增透机理,通过理论计算得出煤层起裂压力、流量、注水量分别为22.8~30.5 MPa、130~200 L/min和216 m^(3)。据此,在揭煤预抽巷道内布设4个水力压裂孔和2个裂隙导向孔。压裂过程中,泵压、平均注水流量、单孔注水量分别达到28~31 MPa、140~177 L/min和260~330 m^(3),同理论计算的数据基本吻合。试验结果表明:定向水力压裂影响半径大于30 m,煤层透气性系数达到0.840 m^(2)/(MPa2·d),是原始煤层的60倍;单孔瓦斯浓度提高50%~80%,百孔抽采纯量达1.9 m^(3)/min,瓦斯抽采量提高90%。采用定向压裂后,揭煤钻孔工程量缩减64%,抽采达标时间比预计工期提前了36 d。该技术可为类似瓦斯治理工程提供借鉴。Aiming at the problems of high gas content and difficult extraction in soft and low-permeability outburst coal seams,as well as the risk of outburst during the coal mining process,directional hydraulic fracturing technology for permeability enhancement and outburst elimination was studied.Firstly,the mechanism of directional hydraulic fracturing for permeability enhancement and outburst elimination was elucidated.Through theoretical calculations,it was found that the initial fracturing pressure,flow rate,and injection volume of the coal seam were 22.8-30.5 MPa,130-200 L/min,and 216 m^(3),respectively.On this basis,4 hydraulic fracturing holes and 2 fracture guide holes were arranged in the pre-extraction roadway.During the fracturing process,the pump pressure,average water injection flow rate,and single hole water injection volume reached 28-31 MPa,140-177 L/min,and 260-330 m',respectively,which were basically consistent with the theoretical calculation data.The experimental results show that the influence radius of directional hydraulic fracturing is greater than 30 meters,and the permeability coefficient of the coal seam reaches O.840 m^(2)/(MPa^(2)·d),which is 60 times that of the original coal seam.The concentration of gas in a single hole has increased by 50%to 80%,and the pure amount of gas extracted from a hundred holes has reached 1.9 m^(3)/min,resulting in a 90%increase in gas extraction capacity.After adopting directional fracturing,the amount of coal drilling work has been reduced by 64%,and the time for reaching the standard of extraction was 36 days ahead of the expected construction period.This technology can provide a reference for similar gas control projects.

关 键 词：松软低透煤层 增透 定向水力压裂 瓦斯抽采 

分 类 号：TD713[矿业工程—矿井通风与安全]