Study on effective extraction radius of bedding borehole under the impact of normal fault
-
摘要: 合理的钻孔有效抽采半径是保证瓦斯抽采效果的关键。但目前对钻孔有效抽采半径的研究主要集中在测定方法方面，缺乏对正断层特殊地质条件下的钻孔有效抽采半径研究。以贵州某矿采煤工作面为工程背景，构建流固耦合模型，采用数值模拟与钻孔抽采瓦斯量法相互验证的方式分析了无断层影响下顺层钻孔有效抽采半径变化规律，结果表明：瓦斯抽采120 d时，有效抽采半径数值模拟结果为3.10 m，现场试验结果为2.93 m，现场试验结果与数值模拟结果基本一致，验证了流固耦合模型的可靠性。利用多物理场耦合仿真软件分析了正断层影响下顺层钻孔有效抽采半径的变化规律，结果表明：在一定抽采时间范围内，钻孔距正断层一定距离时，瓦斯压力曲线会出现驼峰状分布，且峰值间隔约为3.5 m；正断层附近钻孔有效抽采半径随距断层距离的增大而增大，正断层对钻孔有效抽采半径的影响范围在距断层70 m内。结合正断层影响下的分析结果，在保证抽采效果和不延长抽采时间的前提下，对正断层附近瓦斯抽采钻孔布孔间距实施分段布置：在靠近断层30 m内密集布置钻孔，布孔间距应不大于距断层10 m时的有效抽采半径（1.83 m）；在距断层30~70 m范围内，在保证安全的情况下，可适当加大钻孔的布孔间距；在距断层70 m外，可逐步恢复至无正断层影响下顺层钻孔的布孔间距。Abstract: The reasonable effective extraction radius of borehole is the key to ensure gas extraction effect. However, the research of effective extraction radius mainly focuses on the measurement method of effective extraction radius of borehole, and there is a lack of research on the effective extraction radius of borehole under special geological conditions of normal fault. Taking a coal working face in Guizhou as the engineering background, the fluid-solid coupling model is established, and the variation law of effective extraction radius of bedding borehole without fault impact is analyzed by means of mutual verification between numerical simulation and borehole gas extraction method. The results show that when the gas is extracted for 120 days, the effective extraction radius of the numerical simulation is 3.10 m, and that of the field test is 2.93 m. The field results are basically consistent with the numerical simulation results, which verifies the reliability of the fluid-solid coupling model. By using multi-physics field coupling simulation software, the variation law of effective extraction radius of bedding borehole under the impact of normal fault is analyzed. The results show that within a certain extraction time range, when the borehole is at a certain distance from the normal fault, the gas pressure curve will have a hump-like distribution, and the peak interval is about 3.5 m. The effective extraction radius of the borehole near the normal fault increases with the increase of the distance from the fault. The impact of the normal fault on the effective extraction radius of the borehole is within 70 m from the fault. Combined with the analysis results under the impact of normal faults, the spacing of gas drainage boreholes near the normal fault is arranged in sections under the premise of ensuring the extraction effect and not prolonging the extraction time. Within 30 m from the fault, the boreholes are densely arranged, and the spacing between the boreholes should not be greater than the effective extraction radius (1.83 m) when the distance from the fault is 10 m. Within the range of 30-70 m from the fault, under the condition of ensuring safety, the spacing of boreholes can be appropriately increased. After 70 m from the fault, the spacing can be gradually restored to the borehole spacing layout of bedding boreholes without the impact of the normal fault.
-
-
[1] 谢和平,吴立新,郑德志.2025年中国能源消费及煤炭需求预测[J].煤炭学报,2019,44(7):1949-1960. XIE Heping,WU Lixin,ZHENG Dezhi.Prediction on the energy consumption and coal demand of China in 2025[J].Journal of China Coal Society,2019,44(7):1949-1960.
[2] LI Wei,REN Tianwei,BUSCH A,et al.Architecture, stress state and permeability of a fault zone in Jiulishan Coal Mine,China:Implication for coal and gas outbursts[J].International Journal of Coal Geology,2018,198:1-13.
[3] ZHAO Yang,LIN Baiquan,LIU Ting,et al.Mechanism of multifield coupling-induced outburst in mining-disturbed coal seam[J].Fuel,2020,272(4):117716.
[4] 刘咸卫,曹运兴,刘瑞,等.正断层两盘的瓦斯突出分布特征及其地质成因浅析[J].煤炭学报,2000,25(6):571-575. LIU Xianwei,CAO Yunxing,LIU Rui,et al.Analysis on distribution features of gas outburst from two walls of normal fault and geological origin[J].Journal of China Coal Society,2000,25(6):571-575.
[5] 曹运兴,张海洋,张震,等.正断层上盘的煤与瓦斯突出特征与地应力场控制机理[J/OL].煤田地质与勘探.[2022-02-11]. http://kns.cnki.net/kcms/detail/61.1155.P.20211104.1503.002.html. CAO Yunxing,ZHANG Haiyang,ZHANG Zhen,et al.Characteristics of coal and gas outburst and control mechanism of stress field in hanging wall of normal fault[J/OL].Coal Geology & Exploration.[2022-02-11]. http://kns.cnki.net/kcms/detail/61.1155.P.20211104.1503.002.html.
[6] 魏国营,姚念岗.断层带煤体瓦斯地质特征与瓦斯突出的关联[J].辽宁工程技术大学学报(自然科学版),2012,31(5):604-608. WEI Guoying,YAO Niangang.Characteristic of gas-geology at coal seam fault and its association with coal-gas outburst[J].Journal of Liaoning Technical University(Natural Science),2012,31(5):604-608.
[7] GUO Pinkun,CHENG Yuanping,JIN Kan,et al.The impact of faults on the occurrence of coal bed methane in Renlou Coal Mine,Huaibei coalfield,China[J].Journal of Natural Gas Science and Engineering,2014,17:151-158.
[8] 鲁义,申宏敏,秦波涛,等.顺层钻孔瓦斯抽采半径及布孔间距研究[J].采矿与安全工程学报,2015,32(1):156-162. LU Yi,SHEN Hongmin,QIN Botao,et al.Gas drainage radius and borehole distance along seam[J].Journal of Mining & Safety Engineering,2015,32(1):156-162.
[9] 余陶,卢平,孙金华,等.基于钻孔瓦斯流量和压力测定有效抽采半径[J].采矿与安全工程学报, 2012,29(4):596-600. YU Tao,LU Ping,SUN Jinhua,et al.Measurement of effective drainage radius based on gas flow and pressure of boreholes[J].Journal of Mining & Safety Engineering,2012,29(4):596-600.
[10] 刘殿平,马文伟.瓦斯抽采钻孔有效抽采半径测定方法研究[J].工矿自动化,2020,46(11):59-64. LIU Dianping,MA Wenwei.Research on determination method of effective drainage radius of gas drainage borehole[J].Industry and Mine Automation,2020,46(11):59-64.
[11] 韩承强,程波,杨亮,等.煤矿井下钻孔抽采瓦斯影响半径测定方法的研究进展[J].矿业安全与环保,2019,46(5):118-122. HAN Chengqiang,CHENG Bo,YANG Liang,et al.Research progress of measuring method for influencing radius of borehole gas drainage in coal mine[J].Mining Safety & Environmental Protection,2019,46(5):118-122.
[12] 舒才,王宏图,任梅青,等.基于瓦斯抽采量的有效抽采半径数学模型及工程验证[J].采矿与安全工程学报,2017,34(5):1021-1026. SHU Cai,WANG Hongtu,REN Meiqing,et al. Model of effective borehole gas drainage radius based on volume of gas drainage and its engineering verification[J].Journal of Mining & Safety Engineering,2017,34(5):1021-1026.
[13] 王刚,李怀兴,常博.急倾斜煤层瓦斯钻孔有效抽采范围的精准确定[J].煤炭科学技术,2021,49(5):91-99. WANG Gang,LI Huaixing,CHANG Bo.Accurate determination of effective gas extraction range of gas drilling holes in steeply inclined coal seams[J].Coal Science and Technology,2021,49(5):91-99.
[14] 李培超,孔祥言,卢德唐.饱和多孔介质流固耦合渗流的数学模型[J].水动力学研究与进展(A辑),2003,18(4):419-426. LI Peichao,KONG Xiangyan,LU Detang.Mathematical modeling of flow in saturated porous media on account of fluid-structure coupling effect[J].Journal of Hydrodynamics,2003,18(4):419-426.
[15] HU Ke,XIA Binwei,LIU Chengwei,et al.Effective methane extraction radius after high-pressure water jet slotting[J].Geofluids,2020(4):1-12.
计量
- 文章访问数: 152
- HTML全文浏览量: 9
- PDF下载量: 23
下载:
