Coal Geology & Exploration


Permeability is an important parameter to characterize gas flow. In order to ensure the safe and efficient gas drainage, it is necessary to explore the evolution characteristics of coal reservoir gas seepage at different positions from the producing wellbores. However, the effective stress, the gas adsorption/desorption capacity of coal matrix and the temperature of coal reservoir are constantly changing with the gas drainage, and even the drainage damage may occur, which makes the gas migration behavior in coal seam extremely complicated. In order to explore the seepage characteristics of coal reservoir gas during gas drainage, the space-time evolution function of pore pressure affected by temperature was constructed in the cylindrical coordinate system with consideration to the influence of pressure and temperature fields on the permeability of coal reservoir, and the permeability model of coal reservoir under the action of stress and temperature was established accordingly. The results show that the established model could reasonably describe the evolution law of pore pressure along the producing wellbores and the migration characteristics of gas, that is, the pore pressure at different positions decreases firstly and then changes gently with the increase of drainage time under the condition of constant external stress, while the permeability of coal reservoir decreases at first and then increases. In addition, the calculated permeability of coal reservoir considering the temperature is lower than that at the same position without considering temperature. It is found through discussion that the gas drainage could be enhanced with the increasing of drainage time by setting a reasonable negative pressure drainage mode according to the different effects of fracture compression and matrix contraction on permeability evolution.


permeability model, gas drainage, temperature, stress, drainage time




[1] 徐凤银,闫霞,林振盘,等. 我国煤层气高效开发关键技术研究进展与发展方向[J]. 煤田地质与勘探,10/25/2022,50(3):1−14

XU Fengyin,YAN Xia,LIN Zhenpan,et al. Research progress and development direction of key technologies for efficient coalbed methane development in China[J]. Coal Geology & Exploration,10/25/2022,50(3):1−14

[2] LU Shouqing,CHENG Yuanping,LI Wei. Model development and analysis of the evolution of coal permeability under different boundary conditions[J]. Journal of Natural Gas Science and Engineering,2016,31:129−138.

[3] CLARKSON C R,QANBARI F. A semi–analytical method for forecasting wells completed in low permeability,undersaturated CBM reservoirs[J]. Journal of Natural Gas Science and Engineering,2016,30:19−27.

[4] SEIDLE J P,JEANSONNE M W,ERICKSON D J. Application of matchstick geometry to stress dependent permeability in coals[J]. Society of Petroleum Engineers,1992:433−444.

[5] ZHU Wancheng,WEI Chenhui,LIU Jishan,et al. Impact of gas adsorption induced coal matrix damage on the evolution of coal permeability[J]. Rock Mechanics & Rock Engineering,2013,46(6):1353−1366.

[6] XIE Jing,GAO Mingzhong,YU Bin,et al. Coal permeability model on the effect of gas extraction within effective influence zone[J]. Geomechanics and Geophysics for Geo–Energy and Geo–Resources,2015,1:15−27.

[7] SHI Jiquan,DURUCAN S. Drawdown induced changes in permeability of coalbeds:A new interpretation of the reservoir response to primary recovery[J]. Transport in Porous Media,2004,56(1):1−16.

[8] REISABADI M Z,HAGHIGHI M,SALMACHI A,et al. Analytical modelling of coal failure in coal seam gas reservoirs in different stress regimes[J]. International Journal of Rock Mechanics and Mining Sciences,2020,128:104259.

[9] CUI Xiaojun,BUSTIN R M,CHIKATAMARLA L. Adsorption–induced coal swelling and stress:Implications for methane production and acid gas sequestration into coal seams[J]. Journal of Geophysical Research,2007,112:B10202.

[10] 何满潮,王春光,李德建,等. 单轴应力–温度作用下煤中吸附瓦斯解吸特征[J]. 岩石力学与工程学报,2010,29(5):865−872

HE Manchao,WANG Chunguang,LI Dejian,et al. Desorption characteristics of adsorbed gas in coal samples under coupling temperature and uniaxial compression[J]. Chinese Journal of Rock Mechanics and Engineering,2010,29(5):865−872

[11] 牛国庆,颜爱华,刘明举. 瓦斯吸附和解吸过程中温度变化实验研究[J]. 辽宁工程技术大学学报,2003,22(2):155−157

NIU Guoqing,YAN Aihua,LIU Mingju. Experimental study on temperature variation of gas being absorbed and extracted[J]. Journal of Liaoning Technical University,2003,22(2):155−157

[12] 郝建峰,梁冰,孙维吉,等. 考虑吸附/解吸热效应的含瓦斯煤热–流–固耦合模型及数值模拟[J]. 采矿与安全工程学报,2020,37(6):1282−1290

HAO Jianfeng,LIANG Bing,SUN Weiji,et al. Gassy coal thermal–hydraulic–mechanical coupling model and numerical simulation considering adsorption/desorption thermal effect[J]. Journal of Mining & Safety Engineering,2020,37(6):1282−1290

[13] PAN Jienan,HOU Quanlin,JU Yiwen,et al. Coalbed methane sorption related to coal deformation structures at different temperatures and pressures[J]. Fuel,2012,102:760−765.

[14] YIN Guangzhi,JIANG Changbao,WANG Jianguo,et al. Combined effect of stress,pore pressure and temperature on methane permeability in anthracite coal:An experimental study[J]. Transport in Porous Media,2013,100:1−16.

[15] 李志强,鲜学福,隆晴明. 不同温度应力条件下煤体渗透率实验研究[J]. 中国矿业大学学报,2009,38(4):523−527

LI Zhiqiang,XIAN Xuefu,LONG Qingming. Experiment study of coal permeability under different temperature and stress[J]. Journal of China University of Mining & Technology,2009,38(4):523−527

[16] TENG Teng,WANG Jianguo,GAO Feng,et al. A thermally sensitive permeability model for coal–gas interactions including thermal fracturing and volatilization[J]. Journal of Natural Gas Science and Engineering,2016,32:319−333.

[17] ZHU Wancheng,WEI Chenhui,LIU Jishan,et al. A model of coal–gas interaction under variable temperatures[J]. International Journal of Coal Geology,2011,86(2/3):213–221.

[18] 吴学海,李波波,王新,等. 基于塑性变形的煤体损伤本构关系及渗透率模型研究[J]. 煤田地质与勘探,2021,49(6):131−141

WU Xuehai,LI Bobo,WANG Xin,et al. Plastic deformation–based constitutive relation of coal damage and permeability model[J]. Coal Geology & Exploration,2021,49(6):131−141

[19] 许江,李奇贤,彭守建,等. 不同层间压差条件下叠置含气系统的定产合采试验研究[J]. 煤炭科学技术,2020,48(1):46−53

XU Jiang,LI Qixian,PENG Shoujian,et al. Experimental study on commingled production with constant–rate of a multi–superimposed gas system under different interlayer pressure difference[J]. Coal Science and Technology,2020,48(1):46−53

[20] ZHANG Chaolin,XU Jiang,PENG Shoujian,et al. Dynamic evolution of coal reservoir parameters in CBM extraction by parallel boreholes along coal seam[J]. Transport in Porous Media,2018,124(2):325−343.

[21] 贾荔丹,李波波,李建华,等. 采气–采煤阶段煤岩渗透率演化机制研究[J]. 岩石力学与工程学报,10/25/2022,41(1):132−146

JIA Lidan,LI Bobo,LI Jianhua,et al. Study on the evolution mechanism of coal permeability during gas production and coal mining[J]. Chinese Journal of Rock Mechanics and Engineering,10/25/2022,41(1):132−146

[22] FJR E,HOLT R M,HORSRUD P,et al. Stresses around boreholes. Borehole failure criteria[J]. Developments in Petroleum Science,2021,72:201−258.

[23] LEVINE J. Model study of the influence of matrix shrinkage on absolute permeability of coal bed reservoirs[J]. Geological Society Special Publication,1996,109:197−212.

[24] 臧泽升,李忠辉,钮月,等. 不同瓦斯压力下煤体力学特性试验研究[J]. 中国安全科学学报,2021,31(3):90−95

ZANG Zesheng,LI Zhonghui,NIU Yue,et al. Experimental study on mechanical properties of coal under different gas pressure[J]. China Safety Science Journal,2021,31(3):90−95

[25] CONNELL L D,LU MENG,PAN Zhejun. An analytical coal permeability model for tri–axial strain and stress conditions[J]. International Journal of Coal Geology,2010,84(2):103−114.

[26] ZENG Jie,LIU Jishan,LI Wai,et al. A process–based coal swelling model:Bridging the gaps between localized swelling and bulk swelling[J]. Fuel,2021,293:120360.

[27] PENG Yan,LIU Jishan,PAN Zhejun,et al. A sequential model of shale gas transport under the influence of fully coupled multiple processes[J]. Journal of Natural Gas Science and Engineering,2015,27(Part 2):808–821.

[28] LIU Jishan,WANG Jianguo,CHEN Zhongwei,et al. Impact of transition from local swelling to macro swelling on the evolution of coal permeability[J]. International Journal of Coal Geology,2011,88(1):31−40.

[29] XUE Yi,GAO Feng,GAO Yanan,et al. Quantitative evaluation of stress–relief and permeability–increasing effects of overlying coal seams for coal mine methane drainage in Wulan coal mine[J]. Journal of Natural Gas Science and Engineering,2016,32:122−137.

[30] LIU Jishan,CHEN Zhongwei,ELSWORTH D,et al. Interactions of multiple processes during CBM extraction:A critical review[J]. International Journal of Coal Geology,2011,87(3/4):175–189.

[31] ZHANG Shouwen,LIU Jishan,WEI Mingyao,et al. Coal permeability maps under the influence of multiple coupled processes[J]. International Journal of Coal Geology,2018,187:71−82.

[32] 魏明尧. 含瓦斯煤体气固耦合渗流机理及应用研究[D]. 徐州:中国矿业大学,2013.

WEI Mingyao. Study of gas–solid coupling seepage flow in coal containing methane and its application[D]. Xuzhou:China University of Mining and Technology,2013.

[33] LIU Huihai,RUTQVIST J,BERRYMAN J G. On the relationship between stress and elastic strain for porous and fractured rock[J]. International Journal of Rock Mechanics and Mining Sciences,2009,46(2):289−296.

[34] CUI Xiaojun,BUSTIN R M. Volumetric strain associated with methane desorption and its impact on coalbed gas production from deep coal seams[J]. AAPG Bulletin,2005,89(9):1181−1202.

[35] 季淮君,李增华,杨永良,等. 基于瓦斯流场的抽采半径确定方法[J]. 采矿与安全工程学报,2013,30(6):917−921

JI Huaijun,LI Zenghua,YANG Yongliang,et al. Drainage radius measurement based on gas flow field[J]. Journal of Mining & Safety Engineering,2013,30(6):917−921

[36] 程远平,董骏,李伟,等. 负压对瓦斯抽采的作用机制及在瓦斯资源化利用中的应用[J]. 煤炭学报,2017,42(6):1466−1474

CHENG Yuanping,DONG Jun,LI Wei,et al. Effect of negative pressure on coalbed methane extraction and application in the utilization of methane resource[J]. Journal of China Coal Society,2017,42(6):1466−1474



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