| Citation: |
YANG Ming，HAN Longxiang，ZHANG Tiegang，et al. Study on the dynamic evolution of coal pore under variable pressure water injection environment[J]. Journal of China Coal Society，2024，49(S2)：1033−1040. DOI: 10.13225/j.cnki.jccs.XR23.1322
|
The effects of different water injection pressures and confining pressures on the initial pore structure of coal during the water injection process in coal seams are investigated to improve the application effects of water injection technology in dust reduction and outburst prevention. Coal samples from the 2-2 coal seam of Xinqiao Coal Mine are studied based on the low-field nuclear magnetic resonance equipment and the supporting liquid injection and high temperature and pressure circulation experimental system. Water injection experiments on coal samples under three conditions: fixed water injection pressure and fixed confining pressure, variable water injection pressure and fixed confining pressure, and variable confining pressure, are carried out. The dynamic evolution process of coal pore size distribution, porosity and pore volume is analyzed. The results show that the initial pore T2 spectrum of coal samples presents a three-peak structure, with micropores having the largest proportion, followed by mesopores and macropores. Under the influence of water injection pressure and confining pressure, the coal pores show dynamic changes during the water injection process. Pressure water mainly affects the coal pore by expanding the initial pore of the coal body, increasing the number of pores and forming new pores. The radius of the newly formed pores ranges from 0.19×105−1.62×105 nm. The injection of water increases the porosity and pore volume of various types of pores, among which the average increase of macropore porosity reaches 106.31%, and the average pore volume increases by 262.08×10−3 cm3, which is the largest increase. The average increase of micropore porosity is 5.42%, and the average pore volume increases by 57.30×10−3 cm3, which is the smallest increase. The porosity and pore volume of mesopores and small pores also increase, with the porosity increasing by 8.13% and 9.83%, and the pore volume increasing by 69.68×10−3 cm3 and 61.93×10−3 cm3, respectively. At the same time, increasing the water injection pressure can effectively shorten the water injection time. The pore evolution law under variable water injection pressure and fixed water injection pressure conditions is similar, and a sudden increase of macropores occurs when the water injection pressure reaches 11 MPa. The confining pressure mainly affects the coal pores by compressing the micropores and small pores, with a decrease of 29.18% and 28.66%, respectively.
| [1] |
王青松,金龙哲,孙金华. 煤层注水过程分析和煤体润湿机理研究[J]. 安全与环境学报,2004,4(1):70−73. doi: 10.3969/j.issn.1009-6094.2004.01.019
WANG Qingsong, JIN Longzhe, SUN Jinhua. A research on coal seam water infusion course and coal body wetness mechanism[J]. Journal of Safety and Environment,2004,4(1):70−73. doi: 10.3969/j.issn.1009-6094.2004.01.019
|
| [2] |
肖知国,王兆丰. 煤层注水防治煤与瓦斯突出机理的研究现状与进展[J]. 中国安全科学学报,2009,19(10):150−158. doi: 10.3969/j.issn.1003-3033.2009.10.026
XIAO Zhiguo, WANG Zhaofeng. Status and progress of studies on mechanism of preventing coal and gas outburst by coal seam infusion[J]. Journal of Safety and Environment,2009,19(10):150−158. doi: 10.3969/j.issn.1003-3033.2009.10.026
|
| [3] |
郭红玉,苏现波. 煤层注水抑制瓦斯涌出机理研究[J]. 煤炭学报,2010,35(6):928−931.
GUO Hongyu, SU Xianbo. Research on the mechanism of gas emission inhibition in water-flooding coal seam[J]. Journal of China Coal Society,2010,35(6):928−931.
|
| [4] |
石必明,穆朝民. 突出煤层注水湿润防突试验研究[J]. 煤炭科学技术,2013,41(9):147−150.
SHI Biming, MU Chaomin. Experiment study on water injection and moist role for outburst prevention of outburst seam[J]. Coal Science and Technology,2013,41(9):147−150.
|
| [5] |
李沛,马东民,张辉,等. 高、低阶煤润湿性对甲烷吸附/解吸的影响[J]. 煤田地质与勘探,2016,44(5):80−85. doi: 10.3969/j.issn.1001-1986.2016.05.015
LI Pei, MA Dongmin, ZHANG Hui, et al. Influence of high and low rank coal wettability and methane adsorption/desorption characteristics[J]. Coal Geology & Exploration,2016,44(5):80−85. doi: 10.3969/j.issn.1001-1986.2016.05.015
|
| [6] |
蒋仲安,王龙飞,张晋京,等. 煤层注水对原煤孔隙及甲烷吸脱附性能的影响[J]. 煤炭学报,2018,43(10):2780−2788.
JIANG Zhong’an, WANG Longfei, ZHANG Jinjing, et al. Influence of coal water injection on pore and methane adsorption/desorption properties of raw coal[J]. Journal of China Coal Society,2018,43(10):2780−2788.
|
| [7] |
刘忠锋,康天合,鲁伟,等. 煤层注水对煤体力学特性影响的试验[J]. 煤炭科学技术,2010,38(1):17−19.
LIU Zhongfeng, KANG Tianhe, LU Wei, et al. Experiment on water injection affected to mechanics features of coal body[J]. Coal Science and Technology,2010,38(1):17−19.
|
| [8] |
陈辉辉,张小波,姚池,等. 高温作用后岩石裂隙渗流试验及其模型分析[J]. 煤炭学报,2019,44(9):2760−2766.
CHEN Huihui, ZHANG Xiaobo, YAO Chi, et al. Experimental and modeling research on heated rock fracture seepage[J]. Journal of China Coal Society,2019,44(9):2760−2766.
|
| [9] |
JIANG Bo, QU Zhenghui, WANG G G X, et al. Effects of structural deformation on formation of coalbed methane reservoirs in Huaibei coalfield, China[J]. International Journal of Coal Geology, 2010, 82(3−4):175−183.
|
| [10] |
SCHMITT M, FERNANDES C P, DA CUNHA NETO J A B, et al. Characterization of pore systems in seal rocks using nitrogen gas adsorption combined with mercury injection capillary pressure techniques[J]. Marine and Petroleum Geology, 2013, 39(1):138−149.
|
| [11] |
NIE Baisheng, LIU Xianfeng, YANG Longlong, et al. Pore structure characterization of different rank coals using gas adsorption and scanning electron microscopy[J]. Fuel,2015,158:908−917. doi: 10.1016/j.fuel.2015.06.050
|
| [12] |
SHI Xinghua, PAN Jienan, HOU Quanlin, et al. Micrometer-scale fractures in coal related to coal rank based on micro-CT scanning and fractal theory[J]. Fuel,2018,212:162−172. doi: 10.1016/j.fuel.2017.09.115
|
| [13] |
LI Zhentao, LIU Dameng, CAI Yidong, et al. Evaluation of coal petrophysics incorporating fractal characteristics by mercury intrusion porosimetry and low-field NMR[J]. Fuel,2020,263:116802. doi: 10.1016/j.fuel.2019.116802
|
| [14] |
秦文贵,张延松. 煤孔隙分布与煤层注水增量的关系[J]. 煤炭学报,2000,25(5):514−517. doi: 10.3321/j.issn:0253-9993.2000.05.015
QIN Wengui, ZHANG Yansong. Relation of pore distribution of coal with water infusion increment in seams[J]. Journal of China Coal Society,2000,25(5):514−517. doi: 10.3321/j.issn:0253-9993.2000.05.015
|
| [15] |
LIU Yong, XIA Binwei, LIU Xiaotian. A novel method of orienting hydraulic fractures in coal mines and its mechanism of intensified conduction[J]. Journal of Natural Gas Science and Engineering,2015,27:190−199.
|
| [16] |
郭明涛,唐跃刚,苏雪峰,等. 高压注水对煤孔隙结构影响的试验研究[J]. 煤炭科学技术,2017,45(3):133−140.
GUO Mingtao, TANG Yuegang, SU Xuefeng, et al. Experimental study on influence of high pressure water injection on coal pore structure[J]. Coal Science and Technology,2017,45(3):133−140.
|
| [17] |
杨赫,程卫民,刘震,等. 注水煤体有效渗流通道结构分形特征核磁共振试验研究[J]. 岩土力学,2020,41(4):1279−1286.
YANG He, CHENG Weimin, LIU Zhen, et al. Fractal characteristics of effective seepage channel structure of water infusion coal based on NMR experiment[J]. Rock and Soil Mechanics,2020,41(4):1279−1286.
|
| [18] |
周宏伟,刘泽霖,孙晓彤,等. 深部煤体注水过程中渗流通道演化特征[J]. 煤炭学报,2021,46(3):867−875.
ZHOU Hongwei, LIU Zelin, SUN Xiaotong, et al. Evolution characteristics of seepage channel during water infusion in deep coal samples[J]. Journal of China Coal Society,2021,46(3):867−875.
|
| [19] |
李冰,刘见宝,任建刚,等. 水力冲孔对煤微观孔隙和结构成分影响的试验研究[J]. 煤炭科学技术,2021,49(8):131−138.
LI Bing, LIU Jianbao, REN Jiangang, et al. Experimental study of influence of hydraulic punching on microscopic pores and structural components of coal[J]. Coal Science and Technology,2021,49(8):131−138.
|
| [20] |
毛彦军,陈曦,范超男,等. 基于CT三维重建的注水煤岩体裂隙扩展规律研究[J]. 岩土力学,2022,43(6):1717−1726.
MAO Yanjun, CHEN Xi, FAN Chaonan, et al. Crack network evolution of water injection coal and rock mass by means of 3D reconstruction[J]. Rock and Soil Mechanics,2022,43(6):1717−1726.
|
| [21] |
杨明,徐靖,何敏,等. 浸润环境下煤体多态水分布及运移规律[J]. 煤炭学报,2023,48(2):787−794.
YANG Ming, XU Jing, HE Min, et al. Distribution and transport law of polymorphic water in coal body under infiltration environment[J]. Journal of China Coal Society,2023,48(2):787−794.
|
| [22] |
姚艳斌,刘大锰. 基于核磁共振弛豫谱的煤储层岩石物理与流体表征[J]. 煤炭科学技术,2016,44(6):14−22.
YAO Yanbin, LIU Dameng. Petrophysics and fluid properties characterizations of coalbed methane reservoir by using NMR relaxation time analysis[J]. Coal Science and Technology,2016,44(6):14−22.
|
| [23] |
谢松彬,姚艳斌,陈基瑜,等. 煤储层微小孔孔隙结构的低场核磁共振研究[J]. 煤炭学报,2015,40(S1):170−176.
XIE Songbin, YAO Yanbin, CHEN Jiyu, et al. Research of micro-pore structure in coal reservoir using low-field NMR[J]. Journal of China Coal Society,2015,40(S1):170−176.
|
| [24] |
翟成,孙勇,范宜仁,等. 低场核磁共振技术在煤孔隙结构精准表征中的应用与展望[J]. 煤炭学报,2022,47(2):828−848.
ZHAI Cheng, SUN Yong, FAN Yiren, et al. Application and prospect of low-field nuclear magnetic resonance technology in accurate characterization of coal pore structure[J]. Journal of China Coal Society,2022,47(2):828−848.
|
| [25] |
杨明,柳磊,张学博,等. 不同阶煤孔隙结构与流体特性的核磁共振试验研究[J]. 中国安全科学学报,2021,31(1):81−88.
YANG Ming, LIU Lei, ZHANG Xuebo, et al. Nuclear magnetic resonance experimental study on pore structure and fluid characteristics of coal at different ranks[J]. Journal of Safety and Environment,2021,31(1):81−88.
|
| [26] |
LU Yiyu, WANG Li, GE Zhaolong, et al. Fracture and pore structure dynamic evolution of coals during hydraulic fracturing[J]. Fuel,2020,259:116272. doi: 10.1016/j.fuel.2019.116272
|
| [27] |
孙粉锦,杨焦生,王玫珠,等. 不同煤阶煤应力敏感特征及其控制机理[J]. 煤田地质与勘探,2022,50(9):51−58.
SUN Fenjin, YANG Jiaosheng, WANG Meizhu, et al. Stress sensitivity characteristics and control mechanism of different coal rank reservoirs[J]. 2022, 50(9):51−58.
|
Website Copyright © Editorial Department of Coal Journal 京ICP备05086979号-14
Address：Coal Tower,Hepingjie District 13, Chaoyang,Beijing,China
Postal Code：100013
Tel：（010）87986411
Supported by: Beijing Renhe Information Technology Co., Ltd. 
DownLoad: