煤田地质与勘探2025，Vol.53Issue(6)：156-168,13.DOI:10.12363/issn.1001-1986.25.02.0132
基于应力-扩散-渗流耦合模型的低渗煤层水力割缝增透效果分析
Analyzing the permeability enhancement effect of hydraulic slotting for low-permeability coal seams based on a stress-diffusion-seepage coupling model
摘要
Abstract
[Objective and Methods]This study aims to improve the permeability enhancement effect of coal seams for gas drainage.Targeting the soft,low-permeability coal seams with complex gas occurrence conditions in the Baiping mining area and considering the impacts of effective stress,gas migration,actual gas effects,and tortuosity,this study constructed a stress-diffusion-seepage coupling model based on the pore-fracture dual medium assumption.Using the coupling model,this study simulated the variation patterns of gas content in coal seams during gas drainage under vary-ing gas contents and borehole spacings.Through field tests under different permeability enhancement measures and un-loaded coal amounts across borehole intervals,this study compared the permeability enhancement effects of hydraulic flushing,hydraulic slotting,and mechanical reaming to determine the optimal permeability enhancement technique.[Results and Conclusions]The stress-diffusion-seepage coupling model enables accurate characterization of the diffu-sion behavior and flow paths of gas in coal seams.The coal seam thickness and gas content produce significant impacts on the gas drainage effects,with a thicker coal seam and higher gas content associated with a smaller borehole spacing required to achieve effective gas drainage.Under gas contents of ≤7 m3/t,＞7-8 m3/t,and＞8-9.35 m3/t,borehole spa-cings sshould not exceed 11 m,9 m,and 8 m,respectively in the case of coal seam thicknesses ≤1 m,should not ex-ceed 10 m,9 m,and 7 m,respectively if coal seam thicknesses range from＞1 m to 5 m,and should not exceed 10 m,8 m,and 7 m,respectively if coal seam thicknesses vary from＞5 m to 9 m.Field tests indicate that hydraulic flushing,hydraulic slotting,and mechanical reaming all reduce the volume fraction of methane in coal seams and increase the ef-fective gas drainage radius.Notably,these effects prove especially significant in the early drainage stage,while gradu-ally tending to be gentle in the later stage.Under the same technical conditions,hydraulic slotting can deliver optimal performance,reducing the volume fraction of methane by 64.74％ and increasing the effective gas drainage radius by 0.35 m after 90 days of gas drainage.关键词
煤层瓦斯/水力割缝/增透措施/应力-扩散-渗流耦合模型/钻孔布置Key words
coalbed methane(CBM)/hydraulic slotting/permeability enhancement measure/stress-diffusion-seepage coupling model/borehole arrangement分类
矿山工程引用本文复制引用
张宏图,周甜,王登科,李博涛,罗勇,潘荣生,唐家豪,卢卫永..基于应力-扩散-渗流耦合模型的低渗煤层水力割缝增透效果分析[J].煤田地质与勘探,2025,53(6):156-168,13.基金项目
国家自然科学基金项目(52174174) （52174174）
河南省高校科技创新人才支持计划项目(24HASTIT015) （24HASTIT015）
河南理工大学创新团队计划项目(T2022-1) （T2022-1）
