煤层顶板水平井分段水力压裂微震监测与评价  

Microseismic monitoring and assessment of segmented hydraulic fracturing of horizontal wells in coal seam roofs

作　　者：李全贵[1,2] 彭淑悦 梁运培[1,2] 李文禧 钱亚楠 程春晖 余长君 湛金飞 LI Quangui;PENG Shuyue;LIANG Yunpei;LI Wenxi;QIAN Yanan;CHENG Chunhui;YU Changjun;ZHAN Jinfei(State Key Laboratory of Coal Mine Disaster Dynamics and Control,Chongqing University,Chongqing 400044,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China;College of Water Resource and Hydropower,Sichuan University,Chengdu 610065,China;School of Safety Engineering,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]重庆大学煤矿灾害动力学与控制全国重点实验室,重庆400044 [2]重庆大学资源与安全学院,重庆400044 [3]四川大学水利水电学院,四川成都610065 [4]中国矿业大学安全工程学院,江苏徐州221116

出　　处：《煤田地质与勘探》2025年第4期46-57,共12页Coal Geology & Exploration

基　　金：国家自然科学基金面上项目(52474210)。

摘　　要：【背景】微震监测作为一种无损监测技术被广泛用于煤层水力压裂效果评价,但由于建立层状波速模型时缺乏对同层介质中垂向波速梯度的考虑,导致走时计算和震源定位精度有待提高,影响了煤层水力压裂评价的准确性。【目的和方法】以安徽某矿煤层分段水力压裂工程为背景,提出了一种基于泛克里金插值法改进的波速模型。结合各向异性因子约束,在声波测井波速模型的基础上,对同层介质中网格波速数值进行插值计算,表征其各向异性特征,并以此修正弹性波传播路径。通过已知位置射孔事件的震源定位精度对比,验证了改进波速模型的有效性。基于该模型,进一步计算了储层渗透率和储层改造体积(stimulated reservoir volume,SRV),实现了对煤层水力压裂效果的综合评价。【结果与结论】结果表明,泛克里金波速插值相比于线性插值能够有效提升震源定位精度,对于同一射孔点,插值后模型定位误差较初始层状模型最高降低了7.22 m。水力压裂效果评价中,波速插值后的震源定位结果得到改善,微震事件在垂向方向离散性得到有效约束,各压裂段有效影响半径约90 m。煤层区域内微震事件分布密度与渗透率存在差异,各段井筒附近压后渗透率较高。储层改造体积总计为1.977×10~7 m^(3),改造体积及水力裂缝长度与注入总液量正相关,基于微震评价的压裂改造效果与预期设计相符。[Background] Microseismic monitoring,a non-destructive monitoring technique,has been extensively applied in the hydraulic fracturing performance assessment of coal seams.However,little attention is paid to the vertical wave velocity gradients in media in the same layer during the construction of layered wave velocity models.This leads to limited precision of travel time calculation and microseismic source localization,thus affecting the assessment accuracy of the hydraulic fracturing of coal seams.[Objective and Methods] Based on the coal seam segmented hydraulic fracturing project in a mine in Anhui,this study proposes an improved velocity model based on the Universal Kriging interpolation method.By incorporating anisotropy factors,the velocity values in the grid cells of the same layer are interpolated on the basis of the sonic logging velocity model,to characterize the anisotropic features,which are then used to correct the elastic wave propagation path.The effectiveness of the improved velocity model is validated by comparing the source location accuracy of known perforation events.Based on this model,further calculations of reservoir permeability and Stimulated Reservoir Volume(SRV) were performed,achieving a comprehensive evaluation of the coal seam hydraulic fracturing effect.[Results and Conclusions] The results indicate that compared to the linear interpolation method,the universal Kriging interpolation method effectively enhanced the microseismic source localization accuracy.For the same perfo-ration point,the localization errors yielded by the improved wave velocity model decreased by up to 7.22 m compared to those of the initial layered wave velocity model.The hydraulic fracturing performance assessment reveals that the microseismic source localization accuracy after wave velocity interpolation was improved and that the vertical discreteness of microseismic events was effectively restricted,with the effective influence radius of various fracturing segments determined at about 90 m.The distribution den

关 键 词：水力压裂 微震监测 各向异性 泛克里金插值法 波速模型 网格搜索 

分 类 号：TD163[矿业工程—矿山地质测量] P631.4[天文地球—地质矿产勘探]