Mesoscopic law of stress and fracture evolution of coal seams hydraulic fracturing

LI Quangui; DENG Yize; HU Qianting; ZHANG Yuebing; SONG Mingyang; LIU Jichuan; SHI Jialin

doi:10.12363/issn.1001-1986.21.10.0603

Volume 50 Issue 6

Jun 2022

Turn off MathJax

Article Contents

COAL GEOLOGY & EXPLORATION > 2022 > 50(6): 32-40.

LI Quangui，DENG Yize，HU Qianting，et al. Mesoscopic law of stress and fracture evolution of coal seams hydraulic fracturing[J]. Coal Geology & Exploration，2022，50(6)：32−40. doi: 10.12363/issn.1001-1986.21.10.0603

Citation:

PDF( 7967 KB)

Mesoscopic law of stress and fracture evolution of coal seams hydraulic fracturing

doi: 10.12363/issn.1001-1986.21.10.0603

LI Quangui^{1, 2
,},
DENG Yize^{1, 2},
HU Qianting^{1, 2},
ZHANG Yuebing^{1, 2},
SONG Mingyang^{1, 2},
LIU Jichuan^{1, 2},
SHI Jialin^{1, 2}

Received Date: 01 Nov 2021
Rev Recd Date: 13 Jan 2022

Available Online: 30 May 2022

Publish Date: 25 Jun 2022

Abstract

Abstract

Hydraulic fracturing is a technology to increase coal seam permeability, and its stress evolution characteristics and the judgment of fracture morphology and propagation range are particularly important. In this paper, based on directional fracturing, a fluid-structure coupling model of hydraulic fracturing is established by using the discrete element numerical method. The effects of fracturing flow, Poisson’s ratio, natural fracture density on stress evolution and fracture evolution, and their mesoscopic laws are investigated by means of the stress path and crack hot spot diagram. The results show that the stress evolution direction and the final stress path curve shape are obviously different at different fracturing rates. The stress ratio near the crack increases gradually at a low fracturing rate, but increases first and then decreases at a high fracturing rate. The larger the Poisson’s ratio, the smaller the fracture radius, but its influence on fracture initiation time and fracture propagation morphology is not obvious. The development of natural fractures plays a key role in the propagation of hydraulic fractures, and the direction of fracture propagation is more random in coal seams with high natural fracture development, and the direction of stress evolution is reversed. The stress evolution characteristics of different regions can reflect the propagation state of fractures in the fracturing process, the propagation range of the hydraulic fracture network can be determined by monitoring the triaxial stress of several fixed positions near the fracture zone.
- hydraulic fracturing,
- stress evolution,
- crack evolution,
- mesoscopic law,
- discrete element

FullText(HTML)

References(26)

References

[1]	ZHANG Chaolin,WANG Enyuan,XU Jiang,et al. A new method for coal and gas outburst prediction and prevention based on the fragmentation of ejected coal[J]. Fuel,2021,287:119493.. doi: 10.1016/j.fuel.2020.119493
[2]	陈月霞,褚廷湘,陈鹏,等. 瓦斯抽采钻孔间距优化三维数值模拟量化研究[J]. 煤田地质与勘探,2021,49(3):78−84. CHEN Yuexia,CHU Tingxiang,CHEN Peng,et al. Quantitative study of 3D numerical simulation on optimizing borehole layout spacing of gas drainage[J]. Coal Geology & Exploration,2021,49(3):78−84. CHEN Yuexia, CHU Tingxiang, CHEN Peng, et al. Quantitative study of 3D numerical simulation on optimizing borehole layout spacing of gas drainage[J]. Coal Geology & Exploration, 2021, 49(3): 78–84.
[3]	TAO Shu,PAN Zhejun,TANG Shuling,et al. Current status and geological conditions for the applicability of CBM drilling technologies in China:A review[J]. International Journal of Coal Geology,2019,202:95−108.. doi: 10.1016/j.coal.2018.11.020
[4]	李全贵,翟成,林柏泉,等. 定向水力压裂技术研究与应用[J]. 西安科技大学学报,2011,31(6):735−739. LI Quangui,ZHAI Cheng,LIN Baiquan,et al. Research and application of directional hydraulic fracturing technology[J]. Journal of Xi’an University of Science and Technology,2011,31(6):735−739.. doi: 10.3969/j.issn.1672-9315.2011.06.021 LI Quangui, ZHAI Cheng, LIN Baiquan, et al. Research and application of directional hydraulic fracturing technology[J]. Journal of Xi’an University of Science and Technology, 2011, 31(6): 735–739.. doi: 10.3969/j.issn.1672-9315.2011.06.021
[5]	ZHENG Chunshan,JIANG Bingyou,XUE Sheng,et al. Coalbed methane emissions and drainage methods in underground mining for mining safety and environmental benefits:A review[J]. Process Safety and Environmental Protection,2019,127:103−124.. doi: 10.1016/j.psep.2019.05.010
[6]	程玉刚. 煤层水压裂缝导向扩展控制机理及方法[D]. 重庆: 重庆大学, 2018. CHENG Yugang. The mechanism and method of directional hydraulic fracturing in coal seam[D]. Chongqing: Chongqing University, 2018.
[7]	白雪元, 王学滨, 刘桐幸. 考虑单元劈裂的流–固耦合连续–非连续方法及定向水力压裂模拟[J/OL]. 计算力学学报, 2021: 1−8[2022-04-08]. http://kns.cnki.net/kcms/detail/21.1373.O3.20210927.2059.005.html. BAI Xueyuan, WANG Xuebin, LIU Tongxing. A fluid−solid coupling continuum−discontinuum method considering element splitting and simulation of directional hydraulic fracturing[J/OL]. Chinese Journal of Computational Mechanics, 2021: 1–8 [2022-04-08]. http://kns.cnki.net/kcms/detail/21.1373.O3.20210927.2059.005.html.
[8]	董卓,唐世斌. 基于最大周向应变断裂准则定向射孔水力裂缝扩展研究[J]. 岩土力学,2019,40(11):4543−4553. DONG Zhuo,TANG Shibin. Oriented perforation hydraulic fracture propagation based on the maximum tangential strain criterion[J]. Rock and Soil Mechanics,2019,40(11):4543−4553. DONG Zhuo, TANG Shibin. Oriented perforation hydraulic fracture propagation based on the maximum tangential strain criterion[J]. Rock and Soil Mechanics, 2019, 40(11): 4543–4553.
[9]	WANG Tao,HU Wanrui,ELSWORTH D,et al. The effect of natural fractures on hydraulic fracturing propagation in coal seams[J]. Journal of Petroleum Science and Engineering,2017,150:180−190.. doi: 10.1016/j.petrol.2016.12.009
[10]	刘顺,何衡,赵倩云,等. 水力裂缝与天然裂缝交错延伸规律[J]. 石油学报,2018,39(3):320−326. LIU Shun,HE Heng,ZHAO Qianyun,et al. Staggered extension laws of hydraulic fracture and natural fracture[J]. Acta Petrolei Sinica,2018,39(3):320−326.. doi: 10.7623/syxb201803007 LIU Shun, HE Heng, ZHAO Qianyun, et al. Staggered extension laws of hydraulic fracture and natural fracture[J]. Acta Petrolei Sinica, 2018, 39(3): 320–326.. doi: 10.7623/syxb201803007
[11]	GE Zhaolong,ZHONG Jianyu,LU Yiyu,et al. Directional distance prediction model of slotting–directional hydraulic fracturing (SDHF) for coalbed methane (CBM) extraction[J]. Journal of Petroleum Science and Engineering,2019,183:106429.. doi: 10.1016/j.petrol.2019.106429
[12]	CHENG Yugang,LU Yiyu,GE Zhaolong,et al. Experimental study on crack propagation control and mechanism analysis of directional hydraulic fracturing[J]. Fuel,2018,218:316−324.. doi: 10.1016/j.fuel.2018.01.034
[13]	吴拥政,杨建威. 煤矿砂岩横向切槽真三轴定向水力压裂试验[J]. 煤炭学报,2020,45(3):927−935. WU Yongzheng,YANG Jianwei. True tri-axial directional hydraulic fracturing test on sandstone with transverse grooves in coal mine[J]. Journal of China Coal Society,2020,45(3):927−935. WU Yongzheng, YANG Jianwei. True tri-axial directional hydraulic fracturing test on sandstone with transverse grooves in coal mine[J]. Journal of China Coal Society, 2020, 45(3): 927–935.
[14]	贾奇锋,倪小明,赵永超,等. 不同煤体结构煤的水力压裂裂缝延伸规律[J]. 煤田地质与勘探,2019,47(2):51−57. JIA Qifeng,NI Xiaoming,ZHAO Yongchao,et al. Fracture extension law of hydraulic fracture in coal with different structure[J]. Coal Geology & Exploration,2019,47(2):51−57. JIA Qifeng, NI Xiaoming, ZHAO Yongchao, et al. Fracture extension law of hydraulic fracture in coal with different structure[J]. Coal Geology & Exploration, 2019, 47(2): 51–57.
[15]	何涛. 煤岩组合体力学模型及细观损伤过程的颗粒流分析[J]. 煤矿安全,2018,49(11):160−163. HE Tao. Mechanical model of coal and rock mass and particle flow analysis of mesoscopic damage process[J]. Safety in Coal Mines,2018,49(11):160−163. HE Tao. Mechanical model of coal and rock mass and particle flow analysis of mesoscopic damage process[J]. Safety in Coal Mines, 2018, 49(11): 160–163.
[16]	王云飞,黄正均,崔芳. 煤岩破坏过程的细观力学损伤演化机制[J]. 煤炭学报,2014,39(12):2390−2396. WANG Yunfei,HUANG Zhengjun,CUI Fang. Damage evolution mechanism in the failure process of coal rock based on mesomechanics[J]. Journal of China Coal Society,2014,39(12):2390−2396. WANG Yunfei, HUANG Zhengjun, CUI Fang. Damage evolution mechanism in the failure process of coal rock based on mesomechanics[J]. Journal of China Coal Society, 2014, 39(12): 2390–2396.
[17]	刘斌,赵毅鑫,张汉,等. 单轴压缩及劈裂试验下煤的声发射特征研究[J]. 采矿与安全工程学报,2020,37(3):613−621. LIU Bin,ZHAO Yixin,ZHANG Han,et al. Acoustic emission characteristics of coal under uniaxial compression and Brazilian splitting[J]. Journal of Mining & Safety Engineering,2020,37(3):613−621. LIU Bin, ZHAO Yixin, ZHANG Han, et al. Acoustic emission characteristics of coal under uniaxial compression and Brazilian splitting[J]. Journal of Mining & Safety Engineering, 2020, 37(3): 613–621.
[18]	陈鹏宇. PFC^2D模拟裂隙岩石裂纹扩展特征的研究现状[J]. 工程地质学报,2018,26(2):528−539. CHEN Pengyu. Research progress on PFC^2D simulation of crack propagation characteristics of cracked rock[J]. Journal of Engineering Geology,2018,26(2):528−539. CHEN Pengyu. Research progress on PFC^2D simulation of crack propagation characteristics of cracked rock[J]. Journal of Engineering Geology, 2018, 26(2): 528–539.
[19]	POTYONDY D O,CUNDALL P A. A bonded–particle model for rock[J]. International Journal of Rock Mechanics and Mining Sciences,2004,41(8):1329−1364.. doi: 10.1016/j.ijrmms.2004.09.011
[20]	WANG Tao,ZHOU Weibo,CHEN Jinhua,et al. Simulation of hydraulic fracturing using particle flow method and application in a coal mine[J]. International Journal of Coal Geology,2014,121:1−13.. doi: 10.1016/j.coal.2013.10.012
[21]	CHONG Zhaohui,LI Xuehua,CHEN Xiangyu. Effect of injection site on fault activation and seismicity during hydraulic fracturing[J]. Energies,2017,10:1619.. doi: 10.3390/en10101619
[22]	张玉旗. 定向水力压裂裂纹扩展规律的模拟研究[D]. 徐州: 中国矿业大学, 2019. ZHANG Yuqi. Simulation of crack propagation in directional hydraulic fracture[D]. Xuzhou: China University of Mining and Technology, 2019.
[23]	夏磊,曾亚武. 基于PFC^2D数值模拟的交替压裂中应力阴影效应研究[J]. 岩土力学,2018,39(11):4269−4277. XIA Lei,ZENG Yawu. Stress shadow effect of alternative fracturing based on numerical simulation of PFC^2D[J]. Rock and Soil Mechanics,2018,39(11):4269−4277. XIA Lei, ZENG Yawu. Stress shadow effect of alternative fracturing based on numerical simulation of PFC^2D[J]. Rock and Soil Mechanics, 2018, 39(11): 4269–4277.
[24]	康红普,冯彦军. 定向水力压裂工作面煤体应力监测及其演化规律[J]. 煤炭学报,2012,37(12):1953−1959. KANG Hongpu,FENG Yanjun. Monitoring of stress change in coal seam caused by directional hydraulic fracturing in working face with strong roof and its evolution[J]. Journal of China Coal Society,2012,37(12):1953−1959. KANG Hongpu, FENG Yanjun. Monitoring of stress change in coal seam caused by directional hydraulic fracturing in working face with strong roof and its evolution[J]. Journal of China Coal Society, 2012, 37(12): 1953–1959.
[25]	CAI Jianchao,WOOD D A,HAJIBEYGI H,et al. Multiscale and multiphysics influences on fluids in unconventional reservoirs:Modeling and simulation[J]. Advances in Geo−Energy Research,2022,6(2):91−94.
[26]	张培龙. 红庆河煤矿深部开采矿压与支护技术的分析[J]. 内蒙古煤炭经济,2018,30(13):36−37. ZHANG Peilong. Analysis of deep mining pressure and support technology in Hongqinghe coal mine[J]. Inner Mongolia Coal Economy,2018,30(13):36−37.. doi: 10.3969/j.issn.1008-0155.2018.13.020 ZHANG Peilong. Analysis of deep mining pressure and support technology in Hongqinghe coal mine[J]. Inner Mongolia Coal Economy, 2018, 30(13): 36–37.. doi: 10.3969/j.issn.1008-0155.2018.13.020