Coal Geology & Exploration


The presence of small geological structures is the main cause of coal and gas outbursts, making the precise detection of these structures an urgent need. High-precision detection of coal-rock interfaces is essential for identifying small structures and achieving transparent mining faces. The acoustic remote reflection logging technology, with a large detection range, a high resolution, and imaging capability, can accurately identify coal-rock interfaces. In this context, this study proposed a technique for coal-rock interface detection based on acoustic remote reflection logging within crossing boreholes. Specially, by placing acoustic detectors in crossing boreholes, the array waveforms generated by the coal-rock interfaces around the boreholes were collected. Then, the coal-rock interface images were obtained through the inversion of the reflected wave information. This technology, combined with the borehole group in the mining face, allows for the overall exploration of the mining face. The steps are as follows: (1) A numerical model of monopole acoustic remote reflection logging for coal seams was established using the COMSOL Multiphysics software. (2) Through forward modeling, the entire spatio-temporal evolutionary laws of full waveform signals and wavefield snapshots were analyzed. (3) The inversion of the acoustic data for acoustic remote reflection logging was performed, enabling the migration imaging of coal-rock interfaces. The forward modeling results indicate that the compressional wave velocity in a coal seam was approximately 1.2 km/s slower than that in its roof and floor. Acoustic waves exhibited faster energy decay when propagating in a coal seam and showed dominant frequency shifting when spreading through coal-rock interfaces. When a measurement point approached the position where an acoustic detector shifted from the rock layer on a coal seam’s floor to the coal seam, direct waves exhibited a sharp decrease in the amplitude and an increase in sonic time, while reflected waves from the interfaces displayed changes in the slopes of the inclined events in the time-depth domain. Inversion was completed through four steps: filtering, wavefield separation, reflection wave enhancement, and migration imaging. The imaging results closely resembled the original model, with the coal-rock interface dip angles and coal thickness exhibiting errors of 0.6° and 0.212 m, respectively. Therefore, the acoustic remote reflection logging with crossing boreholes based on the finite element method allowed for the effective inversion of the positions and morphological characteristics of coal-rock interfaces. This study will provide fundamental theoretical support for the application of acoustic remote reflection logging technology in the coal-rock interface identification through crossing boreholes.


acoustic remote reflection logging, coal-rock interface imaging, small structure of coal seam, crossing boreholes




[1] LI Peng,CAI Meifeng,GUO Qifeng,et al. Current stress field and its relationship to tectonism in a coal mining district,central China,for underground coal energy exploration[J]. Energy Reports,2022,8:5313−5328.

[2] LI H. Major and minor structural features of a bedding shear zone along a coal seam and related gas outburst,Pingdingshan coalfield,northern China[J]. International Journal of Coal Geology,2001,47(2):101−113.

[3] ZHOU B,HATHERLY P,SUN W. Enhancing the detection of small coal structures by seismic diffraction imaging[J]. International Journal of Coal Geology,2017,178:1−12.

[4] 焦阳,窦文武,谭菁,等. 回采工作面地质构造精细化综合探测技术研究与应用[J]. 中国煤炭,2019,45(11):53−58.

JIAO Yang,DOU Wenwu,TAN Jing,et al. Research and application of fine comprehensive detection technology for geological structure of working face[J]. China Coal,2019,45(11):53−58.

[5] WANG H,WANG Q,HUANG L,et al. Intelligent decision-making system for integrated geological and engineering of deep coalbed methane development[J]. Energy & Fuels,2023,37(18):13976−13984.

[6] 程建远,朱梦博,王云宏,等. 煤炭智能精准开采工作面地质模型梯级构建及其关键技术[J]. 煤炭学报,2019,44(8):2285−2295.

CHENG Jianyuan,ZHU Mengbo,WANG Yunhong,et al. Cascade construction of geological model of longwall panel for intelligent precision coal mining and its key technology[J]. Journal of China Coal Society,2019,44(8):2285−2295.

[7] JIANG Bici,CHENG Jianyuan,LI Ping,et al. Using BHR to detect coal seam interface in coal mine[J]. Journal of Applied Geophysics,2023,209:104894.

[8] 蒋必辞,程建远,李萍,等. 基于钻孔雷达的透明工作面构建方法[J]. 煤田地质与勘探,2022,50(1):128−135.

JIANG Bici,CHENG Jianyuan,LI Ping,et al. Construction method of transparent working face based on borehole radar[J]. Coal Geology & Exploration,2022,50(1):128−135.

[9] 范涛,李萍,张幼振,等. 基于聚类的煤矿井下钻孔瞬变电磁异常响应边界成像方法[J]. 煤田地质与勘探,2022,50(7):63−69.

FAN Tao,LI Ping,ZHANG Youzhen,et al. Imaging method of borehole transient electromagnetic anomaly response boundary in coal mines based on clustering[J]. Coal Geology & Exploration,2022,50(7):63−69.

[10] TANG Hongzhi,YANG Haiyan,LU Guangyin,et al. Small multi-turn coils based on transient electromagnetic method for coal mine detection[J]. Journal of Applied Geophysics,2019,169:165−173.

[11] XUE Guoqiang,CHEN Wen,CHENG Jiulong,et al. A review of electrical and electromagnetic methods for coal mine exploration in China[J]. Ieee Access,2019,7:177332−177341.

[12] 牛德成,苏远大. 基于声波远探测的浅海软地层邻井井眼成像方法[J]. 石油钻探技术,2022,50(6):21−27.

NIU Decheng,SU Yuanda. Adjacent borehole imaging method based on acoustic remote detection in shallow unconsolidated formations[J]. Petroleum Drilling Techniques,2022,50(6):21−27.

[13] HORNBY B. E Imaging of near–borehole structure using full–waveform sonic data[J]. Geophysics,1989,54(6):747−757.

[14] TANG Xiaoming,ZHENG Y,PATTERSON D. Processing array acoustic–logging data to image near–borehole geologic structures[J]. Geophysics,2007,72(2):E87−E97.

[15] TANG Xiaoming,GLASSMAN H,PATTERSON D. Single–well acoustic imaging in anisotropic formations[J]. Geophysics,2008,73(4):D11−D16.

[16] 赵旭东,李国英,刘炳忠. 远探测声波测井仪发射探头研究[J]. 测井技术,2004,28(6):540−542.

ZHAO Xudong,LI Guoying,LIU Bingzhong. On transmitting transducer of far detecting acoustic logging tool[J]. Well Logging Technology,2004,28(6):540−542.

[17] 张承森,肖承文,刘兴礼,等. 远探测声波测井在缝洞型碳酸盐岩储集层评价中的应用[J]. 新疆石油地质,2011,32(3):325−328.

ZHANG Chengsen,XIAO Chengwen,LIU Xingli,et al. Application of remote detection acoustic logging to fractured–vuggy carbonate reservoir evaluation[J]. Xinjiang Petroleum Geology,2011,32(3):325−328.

[18] 柴细元,张文瑞,王贵清,等. 远探测声波反射波成像测井技术在裂缝性储层评价中的应用[J]. 测井技术,2009,33(6):539−543.

CHAI Xiyuan,ZHANG Wenrui,WANG Guiqing,et al. Application of remote exploration acoustic reflection imaging logging technique in fractured reservoir[J]. Well Logging Technology,2009,33(6):539−543.

[19] 董经利,许孝凯,张晋言,等. 声波远探测技术概述及发展[J]. 地球物理学进展,2020,35(2):566−572.

DONG Jingli,XU Xiaokai,ZHANG Jinyan,et al. Overview and development of acoustic far detection technology[J]. Progress in Geophysics,2020,35(2):566−572.

[20] 唐晓明,魏周拓. 声波测井技术的重要进展:偶极横波远探测测井[J]. 应用声学,2012,31(1):10−17.

TANG Xiaoming,WEI Zhoutuo. Significant progress of acoustic logging technology:Remote acoustic reflection imaging of a dipole acoustic system[J]. Applied Acoustics,2012,31(1):10−17.

[21] 李思亦,唐晓明,何娟,等. 基于声波远探测和岩石力学分析的井旁裂缝有效性评价方法[J]. 石油学报,2020,41(11):1388−1395.

LI Siyi,TANG Xiaoming,HE Juan,et al. Fracture characterization combining acoustic reflection imaging and rock mechanics[J]. Acta Petrolei Sinica,2020,41(11):1388−1395.

[22] 唐晓明,李盛清,许松,等. 页岩气藏水平测井裂缝识别及声学成像研究[J]. 测井技术,2017,41(5):501−505.

TANG Xiaoming,LI Shengqing,XU Song,et al. Acoustic characterization and imaging of shale gas fractures in horizontal wells:Field case study in the Sichuan Basin of southwest China[J]. Well Logging Technology,2017,41(5):501−505.

[23] TANG Xiaoming. Imaging near–borehole structure using directional acoustic–wave measurement[J]. Geophysics,2004,69(6):1378−1386.

[24] 李盛清. 声波远探测成像处理方法及地质应用研究[D]. 青岛:中国石油大学(华东),2017.

LI Shengqing. A study on borehole acoustic reflection imaging and geological application[D]. Qingdao:China University of Petroleum (East China),2017.

[25] LIU Liu,SHI Zhenming,TSOFLIAS G P,et al. Detection of karst voids at pile foundation by full–waveform inversion of single borehole sonic data[J]. Soil Dynamics and Earthquake Engineering,2022,152:107048.

[26] CHEN Xuelian,TANG Xiaoming,QIAN Yuping. Simulation of multipole acoustic logging in cracked porous formations[J]. Geophysics,2014,79(1):D1−D10.

[27] WANG Hua,TAO Guo,ZHANG Kuo,et al. Borehole acoustic reflection logging by fdm and fem simulations and data analysis[J]. Seg Technical Program Expanded Abstracts,2013,32:621−625.

[28] 解闯,宋鹏,谭军,等. 声波方程变网格有限差分正演模拟的虚假反射分析[J]. 地球物理学进展,2019,34(2):639−648.

XIE Chuang,SONG Peng,TAN Jun,et al. Analysis of spurious reflections of variable grid finite difference forward modeling based on acoustic wave equation[J]. Progress in Geophysics,2019,34(2):639−648.

[29] LAI Jin,WANG Guiwen,FAN Zhuoying,et al. Fracture detection in oil–based drilling mud using a combination of borehole image and sonic logs[J]. Marine and Petroleum Geology,2017,84:195−214.

[30] TANG Xiaoming,CHEN Xuelian,XU Xiaokai. A cracked porous medium elastic wave theory and its application to interpreting acoustic data from tight formations[J]. Geophysics,2012,77(6):D245−D252.

[31] WANG Bing,TAO Guo,WANG Hua,et al. Extracting near–borehole P and S reflections from array sonic logging data[J]. Journal of Geophysics and Engineering,2011,8(2):308−315.

[32] 魏周拓,陈雪莲,范宜仁,等. 井旁地质界面的反射波模拟及f–k偏移成像[J]. 科学技术与工程,2010,10(36):9044−9047.

WEI Zhoutuo,CHEN Xuelian,FAN Yiren,et al. Study of the sound field numerical simulation and prestack f–k migration imaging of near–borehole geological interface[J]. Science Technology and Engineering,2010,10(36):9044−9047.

[33] 闫怡飞,赵云,宋胜利,等. 基于反射声波测井有限元方法的井旁裂缝分布特征[J]. 中国石油大学学报(自然科学版),2018,42(3):57−63.

YAN Yifei,ZHAO Yun,SONG Shengli,et al. Near wellbore fracture distribution characteristics based on acoustic reflection logging finite element method[J]. Journal of China University of Petroleum (Edition of Natural Science),2018,42(3):57−63.

[34] 雪宇超. 井旁地应力对全波列声波测井影响的正反演研究及应用[D]. 西安:西安石油大学,2021.

XUE Yuchao. Research and application of forward and inverse analysis of the influence of borehole in–situ stress on the full–wave sonic logging[D]. Xi’an:Xi’an Shiyou University,2021.

[35] 邓军,王津睿,任帅京,等. 声波探测技术在矿井领域中的应用及展望[J]. 煤田地质与勘探,2023,51(6):149−162.

DENG Jun,WANG Jinrui,REN Shuaijing,et al. Application and prospect of acoustic detection in the mining sector[J]. Coal Geology & Exploration,2023,51(6):149−162.

[36] HUANG Linlin,LIU Xiangjun,YAN Sen,et al. Experimental study on the acoustic propagation and anisotropy of coal rocks[J]. Petroleum,2022,8(1):31−38.

[37] 孟召平,张吉昌,TIEDEMANN J. 煤系岩石物理力学参数与声波速度之间的关系[J]. 地球物理学报,2006,49(5):1505−1510.

MENG Zhaoping,ZHANG Jichang,TIEDEMANN J. Relationship between physical and mechanical parameters and acoustic wave velocity of coal measures rocks[J]. Chinese Journal of Geophysics,2006,49(5):1505−1510.

[38] WANG Hua,TAO Guo,SHANG Xuefeng. A method to determine the strike of interface outside of borehole by monopole borehole acoustic reflections[J]. Journal of Petroleum Science and Engineering,2015,133:304−312.

[39] 薛洪来,温哲. 煤矿隐伏小断层的瓦斯抽采钻孔探测方法[J]. 煤田地质与勘探,2021,49(3):69−77.

XUE Honglai,WEN Zhe. The concealed small faults detection based on gas drainage boreholes along and cross the coal seam[J]. Coal Geology & Exploration,2021,49(3):69−77.

[40] 王斌. 中国地质钻孔数据库建设及其在地质矿产勘查中的应用[D]. 北京:中国地质大学(北京),2018.

WANG Bin. The construction of the national geological drilling database and its application in geological resource exploration[D]. Beijing:China University of Geosciences (Beijing),2018.

[41] 车小花,乔文孝,阎相祯. 反射声波成像测井的有限元模拟[J]. 应用声学,2004,23(6):1−4.

CHE Xiaohua,QIAO Wenxiao,YAN Xiangzhen. Numerical simulation of borehole acoustic–reflection imaging using the finite element method[J]. Applied Acoustics,2004,23(6):1−4.

[42] 孙志峰,陈洪海,刘西恩. 超声反射成像测井的有限元分析[J]. 应用声学,2013,32(6):495−500.

SUN Zhifeng,CHEN Honghai,LIU Xien. The finite element analysis of ultrasonic reflection method used in acoustic logging[J]. Applied Acoustics,2013,32(6):495−500.

[43] 李丹. 反射声波测井的成像研究[D]. 北京:中国石油大学(北京),2021.

LI Dan. Study on imaging for acoustic reflection imaging logging[D]. Beijing:China University of Petroleum (Beijing),2021.

[44] 徐方慧,王祝文,武焕平. 基于有限差分方法的溶洞地层井孔声波数值模拟[J]. 石油物探,2021,60(3):505−515.

XU Fanghui,WANG Zhuwen,WU Huanping. Finite–difference modeling of borehole acoustic logging in formations with caves[J]. Geophysical Prospecting for Petroleum,2021,60(3):505−515.

[45] 赵云. 基于声波有限元的页岩气储层微裂缝分布规律研究[D]. 青岛:中国石油大学(华东),2017.

ZHAO Yun. Study on fracture distribution of shale gas reservoir based on acoustic finite element method[D]. Qingdao:China University of Petroleum (East China),2017.

[46] 朱特. 基于声波有限元法的页岩气储层压裂裂缝分析[D]. 青岛:中国石油大学(华东),2015.

ZHU Te. Analysis of the shale gas reservoir fracturing cracks based on the acoustic finite element method[D]. Qingdao:China University of Petroleum (East China),2015.

[47] 杨顶辉. 双相各向异性介质中弹性波方程的有限元解法及波场模拟[J]. 地球物理学报,2002,45(4):575−583.

YANG Dinghui. Finite element method of the elastic wave equation and wavefield simulation in two–phase anisotropic media[J]. Chinese Journal of Geophysics,2002,45(4):575−583.

[48] 李全贵,凌发平,胡千庭,等. 煤系地层弹性波阶段性衰减特性分析[J]. 中国矿业大学学报,2023,52(3):466−477.

LI Quangui,LING Faping,HU Qianting,et al. Analysis of phased attenuation characteristics of elastic wave in coal measure strata[J]. Journal of China University of Mining & Technology,2023,52(3):466−477.

[49] 邓呈祥. 井中声波远探测三维数值模拟及成像方法研究[D]. 武汉:中国地质大学,2019.

DENG Chengxiang. Research on three–dimensional numerical modeling and imaging method of single–well acoustic reflection imaging logging[D]. Wuhan:China University of Geosciences,2019.

[50] 刘汇鑫. 压制井中直达波的声波远探测方法研究[D]. 青岛:中国石油大学(华东),2020.

LIU Huixin. Acoustic remote sensing logging method to suppress borehole direct wave[D]. Qingdao:China University of Petroleum(East China),2020.

[51] 王迪. 叠前非平稳资料Q值扫描及反演的动校正方法研究[D]. 北京:中国石油大学(北京),2021.

WANG Di. Scan scheme Q estimation and inversion–based normal moveout correction based on non–stationary prestack gather[D]. Beijing:China University of Petroleum (Beijing),2021.

[52] 王莹,周静,刘豪,等. 反射波提取及偏移叠加概述[J]. 山东化工,2021,50(21):80−82.

WANG Ying,ZHOU Jing,LIU Hao,et al. Summary of acoustic reflection detection technology[J]. Shandong Chemical Industry,2021,50(21):80−82.



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