特厚缓倾斜煤层坚硬厚顶板超长钻孔定向三维水力压裂技术及应用  

Directional three-dimensional hydraulic fracturing technology and its application of super-long borehole in hard and thick roof of extra-thick gently inclined coal seam

作　　者：常博 赵志鹏 杨伟 杨旭 杨欢 郑凯歌 孔令宇 CHANG Bo;ZHAO Zhipeng;YANG Wei;YANG Xu;YANG Huan;ZHENG Kaige;KONG Lingyu(National Energy Group Xinjiang Energy Co.,Ltd.,Urumqi 830000,China;Guoneng Xinjiang Kuangou Mining Co.,Ltd.,Changji 831215,China;Lanzhou Resources&Environment Voc-Tech University,Lanzhou 730030,China;CCTEG Xi’an Research Institute,Xi’an 710077,China)

机构地区：[1]国家能源集团新疆能源有限责任公司,新疆乌鲁木齐830000 [2]国能新疆宽沟矿业有限责任公司,新疆昌吉831215 [3]兰州资源环境职业技术大学,甘肃兰州730030 [4]中煤科工西安研究院(集团)有限公司,陕西西安710077

出　　处：《中国矿业》2023年第11期160-167,共8页China Mining Magazine

摘　　要：针对新疆坚硬厚顶板条件下特厚煤层开采后造成的大面积悬顶可能诱发的强矿压现象,以宽沟煤矿I010206工作面为例,通过理论分析、数值模拟、现场监测、工程试验等方法,分析了特厚缓倾斜煤层顶板垮落形态及坚硬厚顶板强矿压控制思路,明确了合理压裂参数,提出了超长钻孔定向三维水力压裂技术并进行了现场试验。研究结果表明:孔隙水压力随着与钻孔径向距离的增加在5 m内迅速衰减,压裂段间距较小时两裂缝扩展出现影响,易造成裂缝偏转,注水量从20 m3增加至35 m3时,裂纹扩展长度增加50%,综合考虑压裂层位强度、裂纹相互影响范围及压裂效果,确定宽沟煤矿水力压裂最佳参数为:起裂压力17 MPa,钻孔间距50~72 m,压裂段间距30 m,单段注水量为35 m^(3)。基于宽沟煤矿地质条件提出了双厚组合岩层双封单卡多点拖动定向分段水力压裂技术及工艺,压裂后坚硬顶板微震次数大幅降低,顶板来压峰值有效减小。本文研究可为类似条件矿井坚硬厚顶板开采中出现的强矿压现象提供解决思路。In view of the large area hanging roof caused by the mining of extra-thick coal seam under the condition of hard and thick roof in Xinjiang,the phenomenon of strong mine pressure may be induced.Taking the I010206 working face of Kuangou Coal Mine as an example,analyzes the roof caving form of extra-thick gently inclined coal seam and the control idea of strong mine pressure of hard thick roof by theoretical analysis,numerical simulation,field monitoring and engineering test,defines the reasonable fracturing parameters,puts forward the ultra-long borehole directional three-dimensional hydraulic fracturing technology and carries out the field test.The results show that the pore water pressure decreases rapidly within 5 m with the increase of the radial distance from the borehole.When the distance between the fracturing sections is small,the influence of the two fracture propagation is easy to cause the fracture deflection.When the water injection rate increases from 20 m^(3) to 35 m^(3),the crack propagation length increases by 50%.Considering the strength of the fracturing layer,the range of crack interaction and the fracturing effect,the optimal parameters of hydraulic fracturing in Kuangou Coal Mine are determined as follows:the initiation pressure is 17 MPa,the borehole spacing is 50-72 m,the fracturing section spacing is 30 m,and the single section water injection is 35 m3.Based on the geological conditions of Kuangou Coal Mine,the directional staged hydraulic fracturing technology and process of double-thick combined rock strata with double-seal single-card multi-point dragging are proposed.After fracturing,the number of microseismic events of hard roof is greatly reduced,and the peak pressure of roof is effectively reduced.The research in this paper can provide a solution to the phenomenon of strong ground pressure in the mining of hard thick roof in similar conditions.

关 键 词：特厚煤层 坚硬厚顶板 悬顶 定向压裂 矿压防治 

分 类 号：TD322[矿业工程—矿井建设]