Research and application of pulsating acid fracturing technology in coal seam

doi:10.16265/j.cnki.issn 1003-3033.2020.10.011

Abstract

Abstract: In order to solve permeability problem of coal seams with rich minerals, based on hydraulic fracturing theory and mechanism of permeability enhancement by acid solution dissolving coal minerals, pulsating acid fracturing technology was proposed. Then, acid liquid ratio suitable for Zhongneng coal mine was determined by laboratory permeability test method, and field experiment was carried out. The results show that average mixed flow rate and volume fraction of gas extracted from fracturing hole are 3.10 times and 3.39 times of that of ordinary drainage hole, 1.23 times and 1.28 times of that of pulsating hydraulic fracturing hole, and 2.02 times and 2.04 times of that of ordinary hydraulic fracturing hole. By integrating physical enhancement of fractured coal caused by pulse stress wave and chemical enhancement of acid solution coal, pulsating acid fracturing improves development of fracture-pore space structure, and increases gas diffusion and seepage channel in coal. Meanwhile, carbon dioxide generated by acidifying reaction has a displacement effect on gas, which is conducive to efficient and continuous gas extraction.

Key words: pulsating acid fracturing, permeability enhancement technology, permeability test, acid liquid ratio, pulsating stress wave

CLC Number:

X936

JIA Nan. Research and application of pulsating acid fracturing technology in coal seam[J]. China Safety Science Journal, 2020, 30(10): 75-81.

References

[1] 国家能源局.煤层气(煤矿瓦斯)开发利用“十三五”规划[Z].2016-11-24.
[2] 周西华,周丽君,范超军,等.低透煤层水力压裂促进瓦斯抽采模拟与试验研究[J].中国安全科学学报, 2017, 27(10): 81-86.
ZHOU Xihua,ZHOU Lijun,FAN Chaojun.Simulating and experimental study on enhancing gas drainage from low permeability coal seam by hydraulic fracturing [J].China Safety Science Journal,2017, 27(10): 81-86.
[3] 周西华,门金龙,宋东平,等.煤层液态CO₂爆破增透促抽瓦斯技术研究[J].中国安全科学学报, 2015, 25(2): 60-65.
ZHOU Xihua,MEN Jinlong,SONG Dongping,et al.Research on increasing coal seam permeability and promoting gas drainage with liquid CO₂ blasting[J]. China Safety Science Journal, 2015,25(2):60-65.
[4] 林柏泉,李子文,翟成,等.高压脉动水力压裂卸压增透技术及应用[J].采矿与安全工程学报,2011,28(3): 452-455.
LIN Baiquan,LI Ziwen,ZHAI Cheng,et al.Pressure relief and permeability-increasing technology based in high pressure pulsating hydraulic fracturing and its application[J].Journal of Mining and Safety Engineering,2011,28(3): 452-455.
[5] 翟成,李贤忠,李全贵.煤层脉动水力压裂卸压增透技术研究与应用[J].煤炭学报,2011,36(12): 1 996-2 001.
ZHAI Cheng,LI Xianzhong,LI Quangui.Research and application of coal seam pulse hydraulic fracturing technology[J]. Journal of China Coal Society,2011,36(12): 1 996-2 001.
[6] 李贤忠,林柏泉,翟成,等.单一低透煤层脉动水力压裂脉动波破煤岩机理[J].煤炭学报,2013,38(6): 918-923.
LI Xianzhong,LIN Baiquan,ZHAI Cheng,et al.The mechanism of breaking coal and rock by pulsating pressure wave in single low permeability seam[J]. Journal of China Coal Society, 2013,38(6): 918-923.
[7] 吴晶晶,张绍和,孙平贺,等.煤岩脉动水力压裂过程中声发射特征的试验研究[J].中南大学学报,2017,48(7): 1 866-1 874.
WU Jingjing,ZHANG Shaohe,SUN Pinghe,et al.Experimental study on acoustic emission characteristics in coal seam pulse hydraulic fracturing[J].Journal of Central South University,2017,48(7): 1 866-1 874.
[8] 倪小明,李全中,王延斌,等.多组分酸对不同煤阶煤储层化学增透实验研究[J].煤炭学报,2014,39(增2): 436-440.
NI Xiaoming,LI Quanzhong,WANG Yanbin,et al.Experimental study on chemical permeability improvement of different rank coal reservoirs using multi-component acid[J].Journal of China Coal Society,2014,39(S2): 436-440.
[9] 李胜,罗明坤,范超军,等.基于核磁共振和低温氮吸附的煤层酸化增透效果定量表征[J].煤炭学报,2017,42(7): 1 748-1 756.
LI Sheng,LUO Mingkun,FAN Chaojun,et al.Quantitative characterization of the effect of acidification in coals by NMR and low-temperature nitrogen adsorption[J].Journal of China Coal Society,2017,42(7): 1 748-1 756.
[10] 赵博,文光才,孙海涛,等.煤岩渗透率对酸化作用响应规律的试验研究[J].煤炭学报,2017,42(8): 2 019-2 025.
ZHAO Bo,WEN Guangcai,SUN Haitao,et al.Experimental study on response law of permeability of coal to acidification[J]. Journal of China Coal Society,2017,42(8): 2 019-2 025.
[11] 张守宝,田取珍.冲击破煤过程中能量耗散的理论分析[J].太原理工大学学报,2005,36(5): 542-544.
ZHANG Shoubao,TIAN Quzhen.Theoretical analysis of energy dissi-pation during coal impact cutting[J]. Journal of Taiyuan University of Technology,2005,36(5): 542-544.
[12] 卢爱红.应力波诱发冲击矿压的动力学机理研究[M]. 徐州:中国矿业大学出版社,2011: 45-60.

[1]	HE Wen, LU Bokai, SHI Wenfang, ZHU Siyu, LIU Jinpeng. Enhanced permeation effect of fine-grained tailings by ultrasound cavitation [J]. China Safety Science Journal, 2024, 34(5): 91-100.
[2]	XU Na, LIANG Yanxiang, WANG Liang, ZHAO Lili, ZHOU Xueqing, ZHANG Bo. Research on knowledge management in coal mine construction safety field based on knowledge graph [J]. China Safety Science Journal, 2024, 34(5): 28-35.
[3]	YANG Keming, LI Tingting, MA Jun, LI Yaxing, JIANG Kegui, ZHAO Xiangtong. Monitoring of settlement in mining industrial square based on optimal PS point acquisition method [J]. China Safety Science Journal, 2024, 34(5): 44-51.
[4]	PEI Xiaodong, YAO Zhiyuan, WANG Liang, SHAO Hao, WANG Kai, WU Zhengyan. Virtual simulation experimental system for mine fire monitoring and prevention based on Unity3D [J]. China Safety Science Journal, 2024, 34(3): 109-116.
[5]	XU Yongliang, SUN Meng, WANG Lanyun, WANG Yungang. Review of fire smoke flow characteristics and early warning prevention and control of mine belt conveyor [J]. China Safety Science Journal, 2024, 34(3): 117-128.
[6]	LI Min, LUO Ouwen, LU Yi, SHI Shiliang, LI He, LIN Zhijun. Research on spatial distribution pattern of coal spontaneous combustion hazardous zone under condition of regenerated roof [J]. China Safety Science Journal, 2024, 34(3): 129-136.
[7]	WU Fanghua, SHI Shiliang, LU Yi, GU Wangxin, TAN Jiale, LIU Weiting. Fire prevention and extinguishing performance of phosphogypsum based self-produced gas expansion slurry [J]. China Safety Science Journal, 2024, 34(3): 148-154.
[8]	DU Dongdong, LEI Wenjie, LI Donghui, LI Zhe. Study on deviation characteristic of gas extraction borehole drilling in underground coal mine [J]. China Safety Science Journal, 2024, 34(3): 155-161.
[9]	LI Yi, LU Wei, LI Jinliang, CHEN Yunlong, ZHAO Shujie. Study on influencing factors and dust suppression effect of coal seam injection gum-forming dust suppressant [J]. China Safety Science Journal, 2024, 34(3): 171-178.
[10]	YU Haimiao, XU Zepeng, ZHANG Shuo, QI Hui. Knowledge graph analysis of research progress in occupational health of coal miners [J]. China Safety Science Journal, 2024, 34(3): 230-236.
[11]	ZUO Mingcheng, JIAO Wenhua. Helmet-wearing recognition algorithm for coal mine underground operation scenarios [J]. China Safety Science Journal, 2024, 34(3): 237-246.
[12]	ZHANG Zunguo, YUAN Xinli, CHEN Yi, TANG Chao, MA Kaixin, CHEN Yongqiang. Energy evolution characteristics of sandstone under different stress cycle paths [J]. China Safety Science Journal, 2024, 34(2): 144-152.
[13]	YOU Bo, CUI Daxiong, LIU Heqing, LU Yi, YANG Xinyu. Simulation study on heat insulation and cooling of deep shaft tunnel with different heat insulation materials [J]. China Safety Science Journal, 2024, 34(2): 153-160.
[14]	WANG Yongjun, ZHENG Qian, ZHANG Hemeng, DONG Wei, ZHANG Xiaoming, SASAKI Kyuro. Correlation analysis between combustion of underground residual coal and surface carbon flux in goaf [J]. China Safety Science Journal, 2024, 34(2): 161-167.
[15]	GUO Xin, LU Yi, SHI Shiliang, LI He, LI Dafang. Mechanical properties and hydration mechanism of high-flow sealing hole grouting material [J]. China Safety Science Journal, 2024, 34(2): 168-175.