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Coal Geology & Exploration

Abstract

During coalbed methane well drilling, the drilling fluid contaminates and blocks the pores and fractures of coal seam. In order to find out the difference of pollution degree of drilling fluid coal and the contribution rate of the pores and fractures of different scale to permeability, the coal of Changping mine was taken as the research object, the scanning electron microscopy(SEM) and the Image Pro Plus(IPP) processing technology were used, the parameters such as the average length, the average width, the total area and the total perimeter of the fractures of different scales in coal before and after contamination were quantitatively characterized. Based on the fractal theory, the mathematical model of the permeability of the fractures of different scales before and after contamination was established, the change of the permeability before and after contamination was evaluated quantitatively, and was compared with the results of the experimentally tested permeability to verify the feasibility of the calculation method. The results show that after contamination, the average length and the width of fractures of different sizes were reduced, and the decreasing degree was: millimeter scale > nanometer scale > micron scale. The degree of contamination was different in different scales, millimeter scale > micron scale > nanometer scale. The contribution rate of different scales to permeability was different, and the millimeter fracture was the preferential flow channel of fracturing fluid, contributed the most to the permeability, accounting for 46%-72%; the contribution of micron level was the second, accounting for 27%-53%; the contribution of nano scale to permeability was negligible, generally less than 2%. When there are many millimeter and micron scale fractures in coal, and the curvature and width heterogeneity are strong, there may be large-scale to small-scale transformation and small-scale fractures increase. Different injection conditions (such as injection pressure, injection time) and drilling fluid types need to be further studied.

Keywords

fracture, drilling fluid, contamination degree, permeability, Image Pro Plus(IPP), fractal theory

DOI

10.3969/j.issn.1001-1986.2020.06.008

Reference

[1] 程建远,聂爱兰,张鹏. 煤炭物探技术的主要进展及发展趋势[J]. 煤田地质与勘探,2016,44(6):136-141. CHENG Jianyuan,NIE Ailan,ZHANG Peng. Outstanding progress and development trend of coal geophysics[J]. Coal Geology & Exploration,2016,44(6):136-141.

[2] 王琦. 全数字高密度三维地震勘探技术在淮北矿区的应用[J]. 煤田地质与勘探,2018,46(增刊1):41-45. WANG Qi. Application of all digital high density 3D seismic exploration technology in Huaibei mining area[J]. Coal Geology & Exploration,2018,46(Sup.1):41-45.

[3] 赵镨,武喜尊. 高密度采集技术在西部煤炭资源勘探中的应用[J]. 中国煤炭地质,2008,20(6):11-14. ZHAO Pu,WU Xizun. High density acquisition technology and it's application in Western China coal resource exploration[J]. Coal Geology of China,2008,20(6):11-14.

[4] 张宏乐,曹金栋. 用于地球物理勘探的MEMS加速度传感器[J]. 石油仪器,2002,16(4):1-4. ZHANG Hongle,CAO Jindong. MEMS acceleration sensor for geophysical prospecting[J]. Petroleum Instruments,2002,16(2):1-4.

[5] 王喜双,董世泰,王梅生. 全数字地震勘探技术应用效果及展望[J]. 中国石油勘探,2007,12(6):32-36. WANG Xishuang,DONG Shitai,WANG Meisheng. Application and prospect of full digital seismic exploration technology[J]. China Petroleum Exploration,2007,12(6):32-36.

[6] 金丹,程建远,张宪旭. 高密度全数字地震勘探技术在煤田中的应用及效果分析[J]. 煤炭技术,2015,34(8):89-92. JIN Dan,CHENG Jianyuan,ZHANG Xianxu. Application and effect analysis of single-point high-density digital seismic exploration in coal seismic exploration[J]. Coal Technology,2015,34(8):89-92.

[7] 张晓江. 宽、窄方位角三维地震勘探采集方法研究与应用[D]. 北京:中国石油大学,2007. ZHANG Xiaojiang. The research and application of wide and narrow azimuth 3D survey[D]. Beijing:China University of Petroleum,2007.

[8] 刘依谋,印兴耀,张三元,等.宽方位地震勘探技术新进展[J]. 石油地球物理勘探,2014,49(3):596-610. LIU Yimou,YIN Xingyao,ZHANG Sanyuan,et al. Recent advances in wide-azimuth seismic exploration[J]. Oil Geophysical Prospecting,2014,49(3):596-610.

[9] 王华忠."两宽一高"油气地震勘探中的关键问题分析[J]. 石油物探,2019,58(3):313-324. WANG Huazhong. Key problem analysis in seismic exploration based on wide-azimuth,high-density,and broadband seismic data[J]. Geophysical Prospecting for Petroleum,2019,58(3):313-324.

[10] 夏常亮,张红军,郝建波,等. K区块宽方位角地震资料处理[J]. 石油地球物理勘探,2010,45(增刊1):74-79. XIA Changliang,ZHANG Hongjun,HAO Jianbo,et al. Wide azimuth seismic data processing for K block[J]. Oil Geophysical Prospecting,2010,45(Sup.1):74-79.

[11] 刘胜,程增庆,代凤红,等. 煤炭高密度三维地震勘探方法及应用[J]. 煤炭工程,2009(3):67-68. LIU Sheng,CHENG Zengqing,DAI Fenghong,et al. Method and application of high density 3D seismic coal exploration[J]. Coal Engineering,2009(3):67-68.

[12] 李庆忠. 走向精确勘探的道路[M]. 北京:石油工业出版社,1993. LI Qingzhong. The way to obtain a better resolution in seismic prospecting[M]. Beijing:Petroleum Industry Press,1993.

[13] 李振春,王清振. 地震波衰减机理及能量补偿研究综述[J]. 地球物理学进展,2007,22(4):1147-1152. LI Zhenchun,WANG Qingzhen. A review of research on mechanism of seismic attenuation and energy compensation[J]. Progress in Geophysics,2007,22(4):1147-1152.

[14] 张瑾. 地震波能量补偿反Q滤波方法研究[D]. 长春:吉林大学,2013. ZHANG Jin. Study on the inverse Q filtering method for seismic wave energy compensation[D]. Changchun:Jilin University,2013.

[15] 蔡希玲. 俞氏子波在地震数据处理中的应用研究[J]. 石油地球物理勘探,2000,35(4):497-507. CAI Xiling. Application of Yu wavelet to seismic data processing[J]. Oil Geophysical Prospecting,2000,35(4):497-507.

[16] 渥·伊尔马滋. 地震资料分析[M].刘怀山,王克斌,童思友,等,译. 北京:石油工业出版社,2006. ILMAZW. Seismic data analysis[M]. LIU Huaishan,WANG Kebin,TONG Siyou,et al,Translate. Beijing:Petroleum Industry Press,2006.

[17] 宁宏晓,唐东磊,皮红梅,等. 国内陆上"两宽一高"地震勘探技术及发展[J]. 石油物探,2019,58(5):645-653. NING Hongxiao,TANG Donglei,PI Hongmei,et al. The technology and development of "WBH" seismic exploration in land,China[J]. Geophysical Prospecting for Petroleum,2019,2019,58(5):645-653.

[18] CORDSEN A. Narrow-versus wide-azimuth land 3D seismic surveys[J]. Leading Edge,2002,21(8):764-770.

[19] 张保庆,周辉,左黄金,等. 宽方位地震资料处理技术及应用效果[J]. 石油地球物理勘探,2011,46(3):396-400. ZHANG Baoqing,ZHOU Hui,ZUO Huangjin,et al. Wide azimuth data processing techniques and their applications[J]. Oil Geophysical Prospecting,2011,46(3):396-400.

[20] 张公社,马国光,宋玉龙,等. 利用全三维纵波资料进行裂缝检测[J]. 石油地球物理勘探,2004,39(1):41-44. ZHANG Gongshe,MA Guoguang,SONG Yulong,et al. Fracture detection by using full 3-D P-wave data[J]. Oil Geophysical Prospecting,2004,39(1):41-44.

[21] 段文胜,李飞,王彦春,等. 面向宽方位地震处理的炮检距向量片技术[J]. 石油地球物理勘探,2013,48(2):206-213. DUAN Wensheng,LI Fei,WANG Yanchun,et al. Offset vector tile for wide-azimuth seismic processing[J]. Oil Geophysical Prospecting,2013,48(2):206-213.

[22] 马渊明,杨雪霖,张丽梅,等. GeoEast-OVT宽方位处理技术[J]. 石油工业计算机应用,2018,26(2/3/4):31-34. MA Yuanming,YANG Xuelin,ZHANG Limei,et al. GeoEast-OVT wide azimuth processing technology[J]. Computer Applications of Petroleum,2018,26(2/3/4):31-34.

[23] 龚翟韶. 全方位角成像技术在跃满三维中的应用研究[D]. 北京:中国石油大学(北京),2017. GONG Zhaishao. The Applied research of Full-azimuth imaging in Yueman 3D[D]. Beijing:China University of Petroleum(Beijing),2017.

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