Theory and technology of enhanced coal seam gas production by integrated drilling,punching and fracturing in coal mine:Part 1 theory
Shiyao Yu1
Xianbo Su2
Jinxing Song3
Qian Wang4
Zhenjiang You5
1.Institute of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China;Coking Coal Clean Utilization Laboratory Branch of Shanxi Coking Coal Group Co.,Ltd.,Taiyuan,030024,China;Shanxi Provincial Key Laboratory of Intelligent Evaluation and Efficient Utilization of Coking Coal,Taiyuan 030024,China2.Institute of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China;Unconventional Nature Gas Research Institute,Henan Polytechnic University,Jiaozuo 454000,China;School of Energy Resources,China University of Geosciences,Wuhan 430074,China3.School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo 454003,China4.Institute of Resources and Environment,Henan Polytechnic University,Jiaozuo 454000,China5.Center for Sustainable Energy and Resources,Edith Cowan University,Joondalup 6027,Australia
摘要：Coal seams in China are typically characterized by high coal seam gas content and low permeability,posing challenges for efficient coal seam gas extraction.However,achieving successful boreholes,especially in soft coal formations,remains a chal-lenge.The mechanisms underlying permeability improvement in different coal structures need further exploration.Therefore,this paper is focused on the fundamental principles of permeability improvement in soft coal through hydraulic punching,and in hard coal via hydraulic jet fracturing.Firstly,borehole instability results from a dynamic interplay of four factors:in situ stress,coal structure,mechanical properties of coal with fluid,and drilling technology.While borehole instability is inevitable,enhancing drilling tools,drilling media,and drilling processes can mitigate risks associated with buried and stuck drill pipes by ensuring effective discharge of drill cuttings through critical flow velocity and displacement.Secondly,permeability improvement in soft coal through hydraulic punching aims at pressure relief and capacity increase,while in hard coal,hydraulic jet fracturing induces crack formation within the coal seam.Finally,this study illustrates the dynamics of the granular arch in soft coal after hydraulic punching,shedding light on the complex processes involved.
机标关键词：technologyintegratedproductionpunchingpartseamminecoal
论文发表日期：2025-08-31
在线出版日期：2026-01-30（本平台首次上网日期，不代表文献的发表时间）
页数：15( 106-120 )
英文信息