摘要
为解决低渗低压煤层的抽采效率低和突出风险高等难题,以山西福达煤矿为工程背景,基于弹性损伤理论建立围岩渗流—损伤耦合方程,揭示水力压裂过程裂隙动态演化机制。首先,运用RFPA^(2D)-Flow数值模拟软件开展煤层多孔协同钻孔水力压力增透效果模拟,探究不同注水压力、注水流量、压裂时间和压裂孔径影响煤岩裂缝起裂及扩展的程度;其次,通过正交试验法,以有效压力半径为指标,分析各因素对水力压裂效果的影响。研究结果表明:低渗低压煤层水力压裂各因素影响有效压裂半径的主次顺序为:压裂时间>注水流量>注水压力>压裂孔径;有效压裂半径与注水流量、压裂时间具有良好的线性关系,且随注水压力和压裂孔径的增大呈先降低后上升的趋势;注水压力6 MPa、注水流量15 m^(3)/h、压裂孔径72 mm、压裂时间600 s为最佳水力压裂条件。研究结果可为低渗低压煤层水力压裂增透的研究提供参考。
In order toaddress the challenges of low extraction efficiency and high outburst risks in low-permeability and lowpressure coal seams,this study takes ShanxiFuda Coal Mine as the engineering context.Based on elastic damage theory,a coupled seepage-damage equation for surrounding rock was established to reveal the dynamic fracture evolution mechanism during hydraulic fracturingprocess.First,RFPA^(2D)-Flow numerical simulation software was employed to simulate the permeability enhancement effects of multi-borehole collaborative hydraulic fracturing,investigating the extent to which water injection pressure,waterinjectionflow rate,fracturing duration,and fracturing aperture influence the initiation and propagation of coal-rock fractures.Second,orthogonal experiments were conducted using the effective fracturing radius as the evaluation index to analyze the impact of each factor on hydraulic fracturing outcomes.The results indicate thatthe following order of factors affecting effective fracturing radius in hydraulic fracturing of low-permeability and low-pressure coal seam is fracturing duration>waterinjection flow rate>waterinjection pressure>fracturing aperture.The effective fracturing radius exhibits a strong linear relationship with waterinjectionflow rate and fracturing duration,while showing a trend of initially decreasing and then increasing with rising waterinjection pressure and fracture aperture.The optimal hydraulic fracturing conditions are achieved at awaterinjection pressure of 6 MPa,waterinjection flow rate of 15 m3/h,fracture aperture of 72 mm,and fracture duration of 600 s.These findings provide valuable references for hydraulic fracturing permeability enhancement in low-permeability and low-pressure coal seams.
作者
祁云
白晨浩
李绪萍
段宏飞
汪伟
崔欣超
QI Yun;BAI Chenhao;LI Xuping;DUAN Hongfei;WANG Wei;CUI Xinchao(School of Mining and Coal,Inner Mongolia University of Science&Technology,Baotou Inner Mongolia 014010,China;School of Coal Engineering,Shanxi Datong University,Datong Shanxi 037003,China;Editorial Office of China Safety Science Journal,China Occupational Safety and Health Association,Beijing 100029,China;School of Civil Engineering,Sun Yat-sen University,Guangzhou Guangdong 410012,China)
出处
《中国安全生产科学技术》
北大核心
2025年第9期69-76,共8页
Journal of Safety Science and Technology
基金
国家自然科学基金项目(52174188,52464020)
内蒙古自治区自然科学基金项目(2024LHMS05012)
山西省2024年度研究生教育创新计划项目(2024SJ378)
山西大同大学研究生实践创新项目(2024SJCX05)。
关键词
低渗低压
水力压裂
增透
有效压裂半径
裂缝
low-permeability and low-pressure
hydraulic fracturing
permeability enhancement
effective fracturing radius
fractures
作者简介
祁云,博士,副教授,主要研究方向为矿山动力灾害防治及应急技术;通信作者:白晨浩,硕士研究生,主要研究方向为矿山动力灾害防治及应急技术。
