低透气性煤层多孔同步分段水力压裂增透技术研究

doi:10. 11799/ ce202406017

摘要/Abstract

摘要：

为了提高煤层透气性的增透效率，研究了煤层多孔同步分段水力压裂增透技术，介绍了多孔同步分段水力压裂技术的基本原理，通过实验室测试了高压封孔胶囊的耐压强度及多孔同步分段水力压裂系统的自动控制工艺，结果表明：高压封孔胶囊的最小破坏强度为35 MPa，多孔同步分段水力压裂可通过自动控制系统实时监测每个钻孔的压力数据，实现压裂过程的自动控制。同时在三元煤矿进行了现场工业试验, 工业试验表明，3^#煤层的起裂压力为23.3~25.4MPa，当压裂距离为10m时，压裂孔的裂纹扩展时间为26~38min，裂纹沟通时间为28~40min，可有效提高压裂效率。经过多孔同步分段水力压裂增透的煤层，相对于未压裂煤层，在30d的统计时间内，压裂后的平均瓦斯浓度是未压裂的1.12 倍，平均混合流量是未压裂的2.17倍，平均瓦斯纯量是未压裂的2.44 倍，能够有效的增加煤层透气性，提高瓦斯抽采效果。

关键词: 多孔同步压裂 , 分段压裂 , 渗透率 , 卸压增透 , 瓦斯抽采

Abstract:

The multi hole synchronous segmented hydraulic fracturing technology of coal seam is an efficient way to increase the permeability of coal seam. By introducing the basic principle of multi hole synchronous segmented hydraulic fracturing technology, the compressive strength of high-pressure sealing capsule and the automatic control process of multi hole synchronous segmented hydraulic fracturing system were tested in the laboratory, the industrial test was carried out in Sanyuan coal mine, the results show that the minimum damage strength of the high-pressure sealing capsule is 35MPa. The multi-hole synchronous segmented hydraulic fracturing can monitor the pressure data of each borehole in real time through the automatic control system to realize the automatic control of the fracturing process. The industrial test shows that the starting pressure of 3# coal seam is 23.3 ~ 25.4mpa. When the fracturing distance is 10m, the crack propagation time of fracturing hole is 26 ~ 38min and the crack communication time is 28 ~ 40min. The fracturing time is much lower than that of full hole section, which can effectively improve the fracturing efficiency. Compared with the unfractured coal seam, the average gas concentration after fracturing is 1.12 times that of the unfractured coal seam, the average mixing flow is 2.17 times that of the unfractured coal seam, and the average gas purity is 2.44 times that of the unfractured coal seam, which can effectively increase the permeability of the coal seam and improve the gas drainage effect.

中图分类号:

TD712

薛彦平. 低透气性煤层多孔同步分段水力压裂增透技术研究[J]. 煤炭工程, 2024, 56(6): 111-116.

参考文献

[1] 程远平,付建华,俞启香.中国煤矿瓦斯抽采技术的发展[J].采矿与安全工程学报,2009,26(2):127-139.
CHEN Yuanping, FU Jianghua, YU Qixiang. Development of gas extraction technology in coal mines of China[J]. Jou-
rnal of Mining & Sfety Engineering,2009,26(2):127-139.
[2] 赵宝友,王海东.我国低透气性本煤层增透技术现状及气爆增透防突新技术[J].爆破,2014,31(3):32-38.
ZHAO Baoyou, WANG Haidong. Different technologies of permeability enhancement of single coal seam in China and new technique of high pressure gad shock[J].Blasting,2014,
31(3):32-38.
[3] ZHANG Lin, LIU Chiyang, LI Zhihang, et al. Fit gas for foam fracturing in coal layer[J]. Journal of China Coal Society,2008,33(3):322-324.
[4]王耀峰，何学秋，王恩元，等.水力化煤层增透技术研究进展及发展趋势[J].煤炭学报,2014,39(10):1945-1955.
WANG Yaofeng, HE Xueqiu, WANG Enyuan, et al. Research progress and development tendency of the hydraulic technology for increasing the permeability of coal seams[J]. Journal of China Coal Society, 2014,39(10):1945-1955.
[5]焦先军,蔡峰.深部低透气性煤层水力压裂强化增透技术研究[J].煤矿安全，2017,48(10):76-79.DOI: 10.13347/j.cnki.mkaq.2017.10.020.
JIAO Xianjun, CAI Feng.Study on Intensified Permeability Improving Technology by Hydraulic Fracturing in Deep and Low Permeability Coal Seam
[6] 王正帅.碎软煤层顺层钻孔水力割缝增透技术研究[J].煤炭科学技术,2019,47(8):147-151.
WANG Zhengshuai. Research on hydraulic slitting anti-reflection technology for borehole drilled along broken soft coal seam[J]. Coal Science and Technology, 2019,47(8):147-151.
[7] 李艳增.三维旋转水射流扩孔增透技术装备及应用[J].煤矿安全,2015,46(11):124-127.
LI Yanzeng.Technology and Equipment of Three Dimensional Rotation Water-jets Enlarging Bore to Improve Coal Seam Permeability[J].Safety in Coal Mines, 2015,46(11):124-127.
[8]赵丹,李斌,雷云,等. 煤层复合射孔增透技术研究[J].中国安全科学学报,2019,29(6):109-115.
ZHAO Dan,LI Bin,LEI Yun,etal. Research on permeability enhancement of coal seam by compound perforation technology[J]. China Safety Science Journal,2019,29(6):109-115.
[9]马小敏. 超长工作面CO2相变致裂分区增透高效抽采技术试验研究[J].中国安全生产科学技术,2019,15(7):57-61.
MA Xiaomin. Experimental study on partitioned permeability enhancement high-efficiency extraction technology of CO2 phase change fracturing in ultra-long working face[J]. Journal of Safety Science and Technology,2019,15(7):57-61.
[10]吕进国,李守国,赵洪瑞,等. 高地应力条件下高压空气爆破卸压增透技术实验研究[J].煤炭学报,2019,44(4):1115-1128.
LV Jingguo,LI Shouguo,ZHAO Hongrui,etal. Technology of pressure relief and permeability enhancement with high pressure air blasting under high geo-stress[J]. Journal of China Coal Society,2019,44(4):1115-1128.
[11]郭恒.功率超声波技术在低透气性煤层增透试验中的应用[J].能源与环保,2021,43(8):40-44.
GUO Heng. Application of power ultrasonic technology in permeability increasing test of low permeability coal seam[J]. China Energy and Environmental Protection, 2021,43(8):40-44.
[12]杨正宇,闫本正.冲压一体化卸压增透技术在煤层区域瓦斯治理中的应用[J].煤矿安全,2019,50(09):144-146+150.DOI:10.13347/j.cnki.mkaq.2019.09.037.
YANG Zhengyu,YAN Benzheng. Application of Integrated Pressure Relief and Permeability Improvement Technology in Coal Seam Gas Control，2019.09.037.
[13]陈玉涛,秦江涛,谢文波.水力压裂和深孔预裂爆破联合增透技术的应用研究[J].煤矿安全,2018,49(08):141-144+148.DOI:10.13347/j.cnki.mkaq.2018.08.037.
CHEN Yutao, QIN Jiangtao, XIE Wenbo,Application Study on Hydraulic Fracturing and Deep Hole Pre-splitting Blasting Joint Permeability Improvement Technology[J]. 2018.08.037.
[14]覃道雄,朱红青,张民波,等.煤层水力压裂增透技术研究与应用[J].煤炭科学技术,2013,41(5):79-81,85.
QIN Daoxiong, ZHU Hongqing, ZHANG Minbo,et al. Application and research on seam hydraulic fracture permeability improvement technology[J].2013,41(5):79-81,85.
[15]冯仁俊.煤层群分层水力压裂与多层综合压裂增透效果对比研究[J].煤矿安全,2021,52(12):21-28.DOI:10.13347/j.cnki.mkaq.2021.12.006.
FENG Renjun,Comparative study on permeability enhancement effect of separate-layer fracturing and multi-layers comprehensive fracturing in coal seam group[J] 2021,52(12):21-28.
[16]马文伟,李江涛,梁文勖. 煤层定向分段水力压裂增透装置应用试验研究[J].煤炭科学技术,2019,47(5):132-138.
MA Wenwei,LI Jiangtao,LIANG Wenxu.Experimental study and application of directional subdivision hydraulic fracturing and permeability improvement device[J]. Coal Science and Technology, 2019,47(5):132-138.
[17]梁文勖,李江涛,马文伟,等. 点式水力压裂装置的试验研究与应用[J]. 煤炭科学技术,2017,45(4):77-81.
LIANG Wenxu,LI Jiangtao,MA Wenwei,etal. Experiment study and application of point hydraulic fracturing device[J]. Coal Science and Technology, 2017,45(4):77-81.
[18] 杨宏伟.低透气性煤层井下分段点式水力压裂增透[J].北京科技大学学报,2012,34(11):1235-1239.
YANG Hongwei. Underground segmentation point hydraulic fracturing antireflection for low permeability coal seam[J]. Journal of University of Science and Technology Beijing,2012,34(11):1235-1239.
[19]富向,刘洪磊,杨天鸿,等.穿煤层钻孔定向水压致裂的数值仿真[J].东北大学学报(自然科学版),2011,32(10):1480-1483.
FU Xiang, LIU Honglei, YANG Tianhong, et al. Simulating directional hydraulic fracturing through coal seam drilling hole[J]. Journal of Northeastern University (Natural Science),2011,32(10):1480-1483.
[20]富向.井下点式水力压裂增透技术研究[J].煤炭学报,2011,36(8):1317-1321.
FU Xiang. Study of underground point hydraulic fractureing increased permeability technology[J]. Journal of China Coal Society, 2011,36(8):1317-1321.