原位煤层抽采多重应力演化规律及对渗透率控制机制

doi:10.13722/j.cnki.jrme.2022.0280

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摘要单一、首采煤层瓦斯抽采均为原位煤层抽采，是煤矿瓦斯抽采的关键与难点。相较于常规岩石储气层，由于吸附瓦斯作用，抽采过程中煤层力学状态响应更加复杂，其演化规律及对渗透率的控制机制尚不明确。为此，本文在不同应力场条件下开展原位煤层抽采过程中渗透率与力学状态演化规律的研究，探讨多重应力对原位煤层渗透率的控制作用。结果表明：(1) 原位煤层抽采过程中，煤层水平应力与竖直应变整体呈现了先缓慢后快速下降的变化趋势，其中孔隙压力对煤层力学状态的影响满足线性关系，而瓦斯吸附对其影响则满足相似朗格缪尔方程关系，在此基础上，构建综合考虑地应力、孔隙压力及瓦斯吸附三重应力耦合作用的原位煤层力学状态动态演化模型。(2) 煤层渗透率随竖直地应力未见明显变化，而在水平地应力作用下呈现了明显的下降趋势，其主要原因在于煤层割理与水平地应力存在直接的力学作用，而与竖直地应力则不存在这种作用，水平方向的力学状态对渗透率的演化起到了主要控制作用。(3) 原位煤层抽采过程中，渗透率随瓦斯压力降低呈现了先缓慢上升后快速上升的变化趋势，当瓦斯被完全抽出时(极限状态)达到最大值；而仅受孔隙压力作用时，渗透率则表现为缓慢下降的变化趋势。(4) 孔隙压力与瓦斯吸附均会从改变煤层有效应力，以及在煤层内部通过控制基质变形与割理产生相互作用两个方面控制煤层渗透率的演化，其中瓦斯吸附起到了主要控制作用。现有应力依赖型的渗透率模型中，多简单采用有效应力来表征孔隙压力与气体吸附对煤层渗透率的耦合作用，而这往往会忽略煤层内部煤基质与割理间的相互作用而对渗透率产生的影响。

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	刘辉辉1
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	于斌1
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	林柏泉3
	夏彬伟1
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	李全贵1
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	邹全乐1
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关键词 ：采矿工程, 瓦斯抽采, 原位煤层, 渗透率, 多重应力场, 瓦斯吸附

Abstract：Single，first mining coal seam gas extraction are in situ extraction，which is the key and difficulty of coal mine gas extraction. Compared with the conventional gas reservoirs，the mechanical state response of coal seam during extraction is more complex due to gas adsorption，and its evolutionary law and control mechanism on permeability are still unclear. Therefore，in this paper，the evolution of in-situ coal seam permeability and mechanical state during gas extraction were studied under different stress field conditions，and the control effects of multiple stresses on permeability were discussed. Results show that：(1) The coal seam horizontal stress and vertical strain decline slowly at first and then rapidly during the process of gas extraction. The changes in mechanical state with respect to pore pressure satisfies a linear relationship，while this behavior related to gas adsorption can be well described using a Langmuir-like equation. On this basis，a mechanical state model of in-situ coal seam was established considering the coupling effects of geo-stress，pore pressure and gas adsorption. (2) The permeability does not change significantly with vertical geo-stress，but shows a significant downward trend under the action of horizontal geo-stress. This is mainly attributed to the fact that there is a direct mechanical effect between coal seam cleats and horizontal geo-stress，but not with vertical geo-stress. The mechanical state in the horizontal direction plays a major role in controlling the evolution of permeability. (3) During in-situ coal seam extraction，the permeability increases slowly first and then rapidly with the decrease of gas pressure，reaching the maximum value when the gas is completely extracted(final state). However，when only pore pressure is applied，the permeability shows a trend of slow decline. (4) Both pore pressure and gas adsorption control the evolution of permeability by changing the effective stress and the internal interaction between coal matrix and cleats，of these，gas adsorption plays a major controlling role. In the current stress-dependent permeability models，the effective stress is simply used to represent the coupling effect of pore pressure and gas adsorption on the coal seam permeability，but the internal interaction between the coal matrix and cleats is ignored.

Key words： mining engineering gas extraction in-situ coal seam permeability multiple stress field gas adsorption

引用本文:

刘辉辉1，2，于斌1，2，林柏泉3，夏彬伟1，2，李全贵1，2，邹全乐1，2. 原位煤层抽采多重应力演化规律及对渗透率控制机制[J]. 岩石力学与工程学报, 2023, 42(4): 906-917.
LIU Huihui1，2，YU Bin1，2，LIN Baiquan3，XIA Binwei1，2，LI Quangui1，2，ZOU Quanle1，2. Evolution of multiple stresses during in-situ coal seam extraction and its controlling mechanism on permeability. , 2023, 42(4): 906-917.

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http://rockmech.whrsm.ac.cn/CN/10.13722/j.cnki.jrme.2022.0280 或 http://rockmech.whrsm.ac.cn/CN/Y2023/V42/I4/906

[41]	JAEGER J C，COOK N G W，ZIMMERMAN R W. Fundamentals of Rock Mechanics[M]. Malden，USA：Blackwell，2007：169-182.
[29]	COUSSY O. Poromechanics[M]. West Sussex，England：John Wiley and Sons，2004：71-108.
[6]	LIU T，LIU S M，LIN B Q，et al. Stress response during in-situ gas depletion and its impact on permeability and stability of CBM reservoir[J]. Fuel，2020，266：117083.
[24]	ZOBACK M D. Reservoir geomechanics[M]. New York：Cambridge University Press，2008：378-397.
[35]	ADELINA L，MOHAMMAD A A，HOSSEIN M，et al. On swelling stress-strain of coal and their interaction with external stress[J]. Fuel，2022，311：122534.
[20]	LIU S M，HARPALANI S. Permeability prediction of coalbed methane reservoirs during primary depletion[J]. International Journal of Coal Geology，2013，113：1-10.
[9]	赵阳生. 多孔介质多场耦合及其工程响应[M]. 北京：科学出版社，2010：105-112.(ZHAO Yangsheng. Multi-field coupling in porous media and its engineering response[M]. Beijing：Science Press，2010：105-112.(in Chinese))
[31]	GAO Z，LI B B，LI J H，et al. Coal permeability related to matrix-fracture interaction at different temperatures and stresses[J]. Journal of Petroleum Science and Engineering，2021，175：108428.
[33]	WU Y，LIU J S，ELSWORTH D，et al. Development of anisotropic permeability during coalbed methane production[J]. Journal of Natural Gas Science and Engineering，2010，2(4)：197-210.
[37]	马天然，刘卫群，JONNY R，等. 裂隙煤岩各向异性渗透率模型和煤层注气THM耦合行为[J]. 煤炭学报，2017，42(增2)：407-416.(MA Tianran，LIU Weiqun，JONNY R，et al. Anisotropy permeability model for highly fractured coal seams associated with coupled THM analysis of CO2-ECBM[J]. Journal of Chiang Coal Society，2017，42(Supp.2)：407-416.(in Chinese))
[39]	PAN Z J，CONNELL L D. Modelling of anisotropic coal swelling and its impact on permeability behaviour for primary and enhanced coalbed methane recovery[J]. International Journal of Coal Geology，2011，85(3/4)：257-267.
[7]	FENG R M，HARPALANI S，PANDEY R. Laboratory measurement of stress-dependent coal permeability using pulse-decay technique and flow modeling with gas depletion[J]. Fuel，2016，177：76-86.
[18]	PALMER I，MANSOORI J. How permeability depends on stress and pore pressure in coalbeds：A new model[C]// SPE-Asia Pacific Oil and Gas Conference. [S. l.]：[s. n.]，1998：557-564.
[40]	刘辉辉. 煤体瓦斯渗流主控因素演化特性及其对瓦斯抽采控制机制[博士学位论文][D]. 徐州：中国矿业大学，2020.(LIU Huihui. Evolution characteristics of main controlling factors of coal gas seepage and its control mechanism of gas extraction[Ph. D. Thesis][D]. Xuzhou：China University of Mining Science and Technology，2020.(in Chinese))
[5]	LIU S M，HARPALANI S. Evaluation of in situ stress changes with gas depletion of coalbed methane reservoirs[J]. Journal of Geophysical Research：Solid Earth，2014，119(8)：6 263-6 276.
[16]	MAVOR M J，VAUGHN J E. Increasing coal absolute permeability in the San Juan basin Fruitland formation[J]. SPE Reservoir Evaluation and Engineering，1998，1(3)：201-206.
[27]	SHI J Q，DURUCAN S. Drawdown induced changes in permeability of coalbeds：A new interpretation of the reservoir response to primary recovery[J]. Transport in Porous Media，2004，56：1-16.
[38]	肖智勇，王长盛，王刚，等. 基质-裂隙相互作用对渗透率演化的影响：考虑基质变形和应力修正[J]. 岩土工程学报，2021，43(12)：2 209-2 219.(XIAO Zhiyong，WANG Changsheng，WANG Gang，et al. Influences of matrix-fracture interaction on permeability evolution：considering matrix deformation and stress correction[J]. Chinese Journal of Geotechnical Engineering，2021，43(12)：2 209-2 219.(in Chinese))
[1]	袁亮，薛俊华，张农，等. 煤层气抽采和煤与瓦斯共采关键技术现状与展望[J]. 煤炭科学技术，2013，41(9)：6-11.(YUAN Liang，XUE Junhua，ZHANG Nong，et al. Development orientation and status of key technology for mine underground coal bed methane drainage as well as coal and gas simultaneous mining[J]. Coal Science and Technology，2013，41(9)：6-11.(in Chinese))
[3]	邵先杰，董新秀，汤达祯，等. 煤层气开发过程中渗透率动态变化规律及对产能的影响[J]. 煤炭学报，2014，39(增1)：146-151. (SHAO Xianjie，DONG Xinxiu，TANG Dazhen，et al. Permeability dynamic change law and its effect on productivity during coalbed methane development[J]. Journal of China Coal Society，2014，39(Supp.1)：146-151.(in Chinese))
[12]	CONNELL L D. Coupled flow and geomechanical processes during gas production from coal seams[J]. International Journal of Coal Geology，2009，79(1/2)：18-28.
[14]	祝捷，姜耀东，赵毅鑫，等. 考虑吸附作用的各向异性煤体有效应力[J]. 中国矿业大学学报，2010，39(5)：699-704.(ZHU Jie，JIANG Yaodong，ZHAO Yixin，et al. Effective stress of anisotropic coal considering adsorption[J]. Journal of China University of Mining and Technology，2010，39(5)：699-704.(in Chinese))
[23]	OLSON J E，LAUBACH S E，LANDER R H. Natural fracture characterization in tight gas sandstones：Integrating mechanics and diagenesis[J]. American Association of Petroleum Geologists Bulletin，2009，93：1 535-1 549.
[25]	BRACE W F，WALSH J B，FRANGOS W T. Permeability of granite under high pressure[J]. Journal of Geophysical Research，1968，73(6)：2 225-2 236.
[34]	LEVINE J R. Model study of the influence of matrix shrinkage on absolute permeability of coal bed reservoirs[J]. Geological Society Special Publication，1996，109：197-212.
[36]	LAUBACH S E，MARRETT R A，OLSON J E，et al. Characteristics and origins of coal cleat：A review[J]. International Journal of Coal Geology，1998，35(1/4)：175-207.
[10]	ZHAO Y S，HU Y Q，WEI P，et al. The experimental approach to effective stress law of coal mass by effect of methane[J]. Transport in Porous Media，2003，53(3)：235-244.
[21]	MA Q，HARPALANI S，LIU S M. A simplified permeability model for coalbed methane reservoirs based on matchstick strain and constant volume theory[J]. International Journal of Coal Geology，2011，85(1)：43-48.
[32]	REISABADI M Z，HAGHIGHI M，SAYYAFZADEH M，et al. Stress distribution and permeability modelling in coalbed methane reservoirs by considering desorption radius expansion[J]. Fuel，2021，289：119951.
[2]	ZHOU F B，XIA T Q，WANG X X，et al. Recent developments in coal mine methane extraction and utilization in China：A review[J]. Journal of Natural Gas Science and Engineering，2016，31：437-458.
[4]	PAN Z J，CONNELL L D，CAMILLERI M. Laboratory characterization of coal reservoir permeability for primary and enhanced coalbed methane recovery[J]. International Journal of Coal Geology，2010，82(3/4)：252-261.
[8]	SAURABH S，HARPALANI S. The effective stress law for stress-sensitive transversely isotropic rocks[J]. International Journal of Rock Mechanics and Mining Sciences，2018，101：69-77.
[11]	CONNELL L D，DETOURNAY C. Coupled flow and geomechanical processes during enhanced coal seam methane recovery through CO2 sequestration[J]. International Journal of Coal Geology，2009，77(1/2)：222-233.
[13]	陶云奇，许江，彭守建，等. 含瓦斯煤孔隙率和有效应力影响因素试验研究[J]. 岩土力学，2010，31(11)：3 417-3 422.(TAO Yunqi，XU Jiang，PENG Shoujian，et al. Experimental study of influencing factor of porosity and effective stress of gas-filled coal[J]. Rock and Soil Mechanics，2010，31(11)：3 417-3 422.(in Chinese))
[15]	MITRA A，HARPALANI S，LIU S M. Laboratory measurement and modeling of coal permeability with continued methane production：Part 1-Laboratory results[J]. Fuel，2012，94(1)：110-116.
[17]	LIU A，LIU S M，LIU P，et al. The role of sorption-induced coal matrix shrinkage on permeability and stress evolutions under replicated in situ condition for CBM reservoirs[J]. Fuel，2021，294：120530.
[19]	魏建平，秦恒洁，王登科，等. 含瓦斯煤渗透率动态演化模型[J]. 煤炭学报，2015，40(7)：1 555-1 561.(WEI Jianping，QIN Hengjie，WANG Dengke，et al. Dynamic permeability model for coal containing gas[J]. Journal of China Coal Society，2015，40(7)：1 555-1 561.(in Chinese))
[22]	QIN L，ZHAI C，XU J Z，et al. Evolution of the pore structure in coal subjected to freeze-thaw using liquid nitrogen to enhance coalbed methane extraction[J]. Journal of Petroleum Science and Engineering，2019，175：129-139.
[26]	张春会，于永江，岳宏亮，等. 考虑Klinbenberg效应的煤中应力-渗流耦合数学模型[J]. 岩土力学，2010，31(10)：3 217-3 222. (ZHANG Chunhui，YU Yongjiang，YUE Hongliang，et al. Seepage-stress coupled model of coal with Klinbenberg effect[J]. Rock and Soil Mechanics，2010，31(10)：3 217-3 222.(in Chinese))
[28]	LIU S M，HARPALANI S，PILLALAMARRY M. Laboratory measurement and modeling of coal permeability with continued methane production：Part 2-Modeling results[J]. Fuel，2012，94(1)：117-124.
[30]	CUI X J，BUSTIN R M. Volumetric strain associated with methane desorption and its impact on coalbed gas production from deep coal seams[J]. American Association of Petroleum Geologists Bulletin，2005，89(9)：1 181-1 202.