Evolution law of pulsating seepage and thermal deformation by injecting high-temperature steam into coal for thermal coalbed methane recovery  

作　　者：Zhiqiang Li Junliang Li Jinsheng Chen Ali Karrech Ningchao Zhang Ju Chang Kaiqi Jin Yangyang Yu Hongbin Wang Aijie Wang 

机构地区：[1]MOE Engineering Center of Mine Disaster Prevention and Rescue,Henan Polytechnic University,Jiaozuo,China [2]Collaborative Innovation Center of Coal Work Safety and Clean High Efficiency Utilization,Henan Polytechnic University,Jiaozuo,China [3]School of Safety Science and Engineering,Henan Polytechnic University,Jiaozuo,China [4]Henan Provincial Key Lab of Gas Geology and Control-Cultivation Base of Provincial and Ministry Joint State Key,Henan Polytechnic University,Jiaozuo,China [5]School of Engineering,The University of Western Australia,Perth,Australia

出　　处：《Deep Underground Science and Engineering》2025年第1期119-131,共13页深地科学(英文)

基　　金：Fundamental Research Funds for the Universities of Henan Province,Grant/Award Number:NSFRF180305。

摘　　要：Chinese coal reservoirs are characterized by low pressure and low permeability,which need to be enhanced so as to increase production.However,conventional methods for permeability enhancement can only increase the permeability in fractures,but not the ultra-low permeability in coal matrices.Attempts to enhance such impermeable structures lead to rapid attenuation of gas production,especially in the late stage of gas extraction.Thermal stimulation by injecting high-temperature steam is a promising method to increase gas production.The critical scientific challenges that still hinder its widespread application are related to the evolution law of permeability of high-temperature steam in coal and the thermal deformation of coal.In this study,an experimental approach is developed to explore the high-temperature steam seepage coupled with the thermal deformation in coal under triaxial stress.The tests were conducted using cylindrical coal specimens of?50 mm×100 mm.The permeability and thermal strain in coal were investigated when high-temperature steam was injected at151.11,183.20,213.65,and 239.76°C.The experimental results reveal for the first time that as the amount of injected fluid increases,the steam permeability shows periodic pulsation changes.This paper introduces and explains the main traits of this discovery that may shed more light on the seepage phenomenon.When the injected steam temperature increases,the amplitude of pulsating permeability decreases,whereas the frequency increases;meanwhile,the period becomes shorter,the pulsation peak appears earlier,and the stabilization time becomes longer.The average peak permeability shows a“U-shaped”trend,decreasing first and then increasing as the steam temperature increases.Meanwhile,with the extension of steam injection time,the axial,radial,and volumetric strains of coal show a stage-wise expansion characteristic at different temperatures of steam injection,except for the radial strains at 151.11°C.A two-phase flow theory of gas–liquid is adopted to el

关 键 词：coalbed methane PERMEABILITY PULSATION STEAM thermal deformation two-phase flow 

分 类 号：P61[天文地球—矿床学]