•  
  •  
 

Coal Geology & Exploration

Abstract

Objective Deep coalbed methane (CBM), representing one crucial resource successor for ensuring the oil and gas security of China and achieving peak carbon dioxide emissions and carbon neutrality of the country, exhibits broad prospects for production. However, due to the small low universality of CBM production technologies under varying geological conditions, a technology that has been successfully applied in some blocks cannot be directly extended to other blocks. This leads to blind deployment of well types and well patterns in the early-stage exploration and development of new blocks to a certain extent. Given this, it is necessary to develop a suitable reservoir stimulation technology for efficient deep CBM production in the Shenfu block. Methods First, based on the actual data of 79 production wells in the Shenfu block, this study compared the performance of vertical and horizontal wells from the aspects of production capacity and economic benefits. Second, taking the geological conditions of deep coal seams in the Shenfu block as input parameters, this study conducted a simulation analysis of the reasonable horizontal well length for deep CBM production. Last, by combining multiple disciplines such as geology, gas reservoirs, drilling and completion, engineering, and economic evaluation and taking the economic benefits per unit area as the goal of optimization, this study determined the specific technological parameters of reservoir stimulation for efficient deep CBM production in the Shenfu block. Results and Conclusions The results indicate that horizontal wells are suitable for the production of deep CBM in the Shenfu block, with maximum economic benefits being obtained under a horizontal well length range of 800‒1500 m. Furthermore, the optimal well spacing, cluster spacing, and fracture half-length were determined at 300 m, 15‒20 m, and 120 m, respectively, corresponding to a total fracturing fluid volume ranging from 18000 to 24000 m3 and a total proppant volume varying between 2 500 and 3 500 m3. Based on these results, this study developed a set of reservoir stimulation technologies suitable for deep coal seams in the Shenfu block, with the core consisting of multiple clusters within a perforation section, shortened cluster spacing, high injection rates of fracturing fluids, fracturing and proppant transport via variable-viscosity slickwater, high-intensity proppant injection, propping of fractures on various scales, equal-aperture limited-entry perforating, creation of complex fracture networks. This study achieved the efficient production of deep CBM in the Shenfu block, providing a reference for the production of deep CBM in other basins of China.

Keywords

deep coalbed methane(CBM), hydraulic fracturing, reservoir stimulation, Shenfu block

DOI

10.12363/issn.1001-1986.24.01.0082

Reference

[1] 李勇,孟尚志,吴鹏,等. 煤层气成藏机理及气藏类型划分:以鄂尔多斯盆地东缘为例[J]. 天然气工业,2017,37(8):22−30.

LI Yong,MENG Shangzhi,WU Peng,et al. Accumuation mecha- nisms and classification of CBM reservoir types:A case study from the eastern margine of the Ordos Basin[J]. Natural Gas Industry,2017,37(8):22−30.

[2] 赵庆波,孔祥文,赵奇. 煤层气成藏条件及开采特征[J]. 石油与天然气地质,2012,33(4):552−560.

ZHAO Qingbo,KONG Xiangwen,ZHAO Qi. Coalbed methane accumulation conditions and production characteristics[J]. Oil & Gas Geology,2012,33(4):552−560.

[3] 徐凤银,张伟,李子玲,等. 鄂尔多斯盆地保德区块煤层气藏描述与提高采收率关键技术[J]. 天然气工业,2023,43(1):96−112.

XU Fengyin,ZHANG Wei,LI Ziling,et al. Coalbed methane reservoir description and enhanced recovery technologies in Baode block,Ordos Basin[J]. Natural Gas Industry,2023,43(1):96−112.

[4] 张道勇,朱杰,赵先良,等. 全国煤层气资源动态评价与可利用性分析[J]. 煤炭学报,2018,43(6):1598−1604.

ZHANG Daoyong,ZHU Jie,ZHAO Xianliang,et al. Dynamic assessment of coalbed methane resources and availability in China[J]. Journal of China Coal Society,2018,43(6):1598−1604.

[5] 徐凤银,肖芝华,陈东,等. 我国煤层气开发技术现状与发展方向[J]. 煤炭科学技术,2019,47(10):205−215.

XU Fengyin,XIAO Zhihua,CHEN Dong,et al. Current status and development direction of coalbed methane exploration technology in China[J]. Coal Science and Technology,2019,47(10):205−215.

[6] 张抗,张立勤,刘冬梅. 近年中国油气勘探开发形势及发展建议[J]. 石油学报,2022,43(1):15−28.

Zhang Kang,Zhang Liqin,Liu Dongmei. Situation of China’s oil and gas exploration and development in recent years and relevant suggestions[J]. Acta Petrolei Sinica,2022,43(1):15−28.

[7] 黄中伟,李国富,杨睿月,等. 我国煤层气开发技术现状与发展趋势[J]. 煤炭学报,2022,47(9):3212−3238.

HUANG Zhongwei,LI Guofu,YANG Ruiyue,et al. Review and development trends of coalbed methane exploitation technology in China[J]. Journal of China Coal Society,2022,47(9):3212−3238.

[8] 徐凤银,闫霞,李曙光. 鄂尔多斯盆地东缘深部(层)煤层气勘探开发理论技术难点与对策[J]. 煤田地质与勘探,2023,51(1):115−130.

XU Fengyin,YAN Xia,LI Shuguang,et al. Theoretical and technological difficulties and countermeasures of deep CBM exploration and development in the eastern edge of Ordos Basin[J]. Coal Geology & Exploration,2023,51(1):115−130.

[9] 张群,降文萍,姜在炳,等. 我国煤矿区煤层气地面开发现状及技术研究进展[J]. 煤田地质与勘探,2023,51(1):139−158.

ZHANG Qun,JIYAN Wenping,JIYAN Zaibing,et al. Present situation and technical research progress of coalbed methane surface development in coal mining area of China[J]. Coal Geology & Exploration,2023,51(1):139−158.

[10] 张懿,朱光辉,郑求根,等. 中国煤层气资源分布特征及勘探研究建议[J]. 非常规油气,2022,9(4):1−8.

ZHANG Yi,ZHU Guanghui,ZHENG Qiugen,et al. Distribution characteristics of coalbed methane resources in China and recommendations for exploration research[J]. Unconventional Oil & Gas,2022,9(4):1−8.

[11] 徐继发,王升辉,孙婷婷,等. 世界煤层气产业发展概况[J]. 中国矿业,2012,21(9):24−28.

XU Jifa,WANG Shenghui,SUN Tingting,et al. The introduction of world CBM development[J]. China Mining Magazine,2012,21(9):24−28.

[12] 杨秀春,毛建设,林文姬,等. 保德区块煤层气勘探历程与启示[J]. 新疆石油地质,2021,42(03):381−388.

YANG Xiuchun,MAO Jianshe,LIN Wenji,et al. Exploration History and Enlightenment of Coalbed Methane in Baode Block[J]. Xinjiang Petroleum Geology,2021,42(03):381−388.

[13] 李春,张云鹏,张璐,等. 沁水盆地深煤层储层特征及压裂改造技术[J]. 煤炭技术,2016,35(8):94−97.

LI Chun,ZHANG Yunpeng,ZHANG Lu,et al. Characteristics of Deep Coal Seam and Fracturing Technology in Qinshui Basin[J]. Coal Technology,2016,35(8):94−97.

[14] 覃木广. 井下煤层水力压裂理论与技术研究现状及发展方向[J]. 中国矿业,2021,30(6):112−119.

QIN Muguang. Research status and development direction of theory and technology of hydraulic fracturing for underground coal seam[J]. China Mining Magazine,2021,30(6):112−119.

[15] 吴聿元,陈贞龙. 延川南深部煤层气勘探开发面临的挑战和对策[J]. 油气藏评价与开发,2020,10(4):1−11.

WU Yuyuan,CHEN Zhenlong. Challenges and countermeasures for exploration and development of deep CBM of South Yanchuan[J]. Reservoir Evaluation and Development,2020,10(4):1−11.

[16] 姚红生,陈贞龙,何希鹏,等. 深部煤层气“有效支撑”理念及创新实践:以鄂尔多斯盆地延川南煤层气田为例[J]. 天然气工业,2022,42(6):97−106.

YAO Hongsheng,CHEN Zhenlong,HE Xipeng,et al. "Effective support" concept and innovative practice of deep CBM in South Yanchuan Gas Field of the Ordos Basin[J]. Natural Gas Industry,2022,42(6):97−106.

[17] 李勇,汤达祯,孟尚志,等. 鄂尔多斯盆地东缘煤储层地应力状态及其对煤层气勘探开发的影响[J]. 矿业科学学报,2017,2(5):416−424.

LI Yong,TANG Dazhen,MENG Shangzhi,et al. The in–situ stress of coal reservoirs in east margin of Ordos Basin and its influence on coalbed methane development[J]. Journal of Mining Science and Technology,2017,2(5):416−424.

[18] 唐书恒,朱宝存,颜志丰. 地应力对煤层气井水力压裂裂缝发育的影响[J]. 煤炭学报,2011,36(1):65−69.

TANG Shuheng,ZHU Baocun,YAN Zhifeng. Effect of crustal stress on hydraulic fracturing in coalbed methane wells[J]. Journal of China Coal Society,2011,36(1):65−69.

[19] 王锡勇,张庆龙,王良书,等. 鄂尔多斯盆地东缘中—新生代构造特征及构造应力场分析[J]. 地质通报,2010,29(8):1168−1176.

WANG Xiyong,ZHANG Qinglong,WANG Liangshu,et al. Structural features and tectonic stress fields of the Mesozoic and Cenozoic in the eastern margin of the Ordos basin,China[J]. Geological Bulletin of China,2010,29(8):1168−1176.

[20] 贾进章,王东明,李斌. 水力压裂有效压裂半径的影响因素研究[J]. 中国安全生产科学技术,2022,18(6):58−64.

JIA Jinzhang,WANG Dongming,LI Bin. Study on influencing factors of effective fracturing radius of hydraulic fracturing[J]. Journal of Safety Science and Technology,2022,18(6):58−64.

[21] 闫江平,庞长庆,段建华,等. 煤矿井下水力压裂范围微震监测技术及其影响因素[J]. 煤田地质与勘探,2019,47(S01):92−97.

YAN Jiangping,PANG Changqing,DUAN Jianhua,et al. Microseismic monitoring of underground hydraulic fracturing range in coal seam and analysis of influencing factors[J]. Coal Geology & Exploration,2019,47(S01):92−97.

[22] 魏迎春,王亚东,张劲,等. 煤层气水平井钻井工程因素对煤粉产出影响的数值模拟:以柳林区块为例[J]. 矿业科学学报,2022,7(6):670−679.

WEI Yingchun,WANG Yadong,ZHANG Jin,et al. Numerical simulation on the effect of drilling engineering factors on coal fines output in coalbed methane horizontal wells:A case study of Liulin Block[J]. Journal of Mining Science and Technology,2022,7(6):670−679.

[23] 赵俊芳,王生维,秦义,等. 煤层气井煤粉特征及成因研究[J]. 天然气地球科学,2013,24(6):1316−1320.

ZHAO Junfang,WANG Shengwei,QIN Yi,et al. Characteristics and Origin of Coal Powder in Coalbed Methane Well[J]. Natural Gas Geoscience,2013,24(6):1316−1320.

[24] 曹代勇,袁远,魏迎春,等. 煤粉的成因机制-产出位置综合分类研究[J]. 中国煤炭地质,2012,24(1):10−12.

CAO Daiyong,YUAN yuan,WEI Yingchun,et al. Comprehensive Classification Study of Coal Fines Genetic Mechanism and Origin Site[J]. COAL GEOLOGY OF CHINA,2012,24(1):10−12.

[25] 杨兆中,何睿,师斌斌,等. 深煤层直井水力压裂难点剖析及技术对策[J]. 煤炭技术,2017,36(11):123−126.

YANG Zhaozhong,HE Rui,SHI Bingbing,et al. Difficulties Analysis and Technical Strategies on Hydraulic Fracturing of Deep Coalbed Methane Vertical Wells[J]. Coal Technology,2017,36(11):123−126.

[26] 周德华,陈刚,陈贞龙,等. 中国深层煤层气勘探开发进展、关键评价参数与前景展望[J]. 天然气工业,2022,42(6):43−51.

ZHOU Dehua,CHEN Gang,CHEN Zhenlong,et al. Exploration and development progress,key evaluation parameters and prospect of deep CBM in China[J]. Natural Gas Industry,2022,42(6):43−51.

[27] 刘建忠,朱光辉,刘彦成,等. 鄂尔多斯盆地东缘深部煤层气勘探突破及未来面临的挑战与对策:以临兴—神府区块为例[J]. 石油学报,2023,44(11):1827−1839.

LIU Jianzhong,ZHUGuanghui,LIU Yancheng,et al. Breakthrough,future challenges and countermeasures of deep coalbed methane in the eastern margin of Ordos Basin:a case study of Linxing-Shenfu block[J]. Acta Petrolei Sinica,2023,44(11):1827−1839.

[28] 何登发,包洪平,开百泽,等. 鄂尔多斯盆地及其邻区关键构造变革期次及其特征[J]. 石油学报,2021,42(10):1255−1269.

HE Dengfa,BAO Hongping,KAl Baize,et al. Critical tectonic modification periods and its geologic features of Ordos Basin and adjacent area[J]. Acta Petrolei Sinica,2021,42(10):1255−1269.

[29] 贾爱林,位云生,郭智,等. 中国致密砂岩气开发现状与前景展望[J]. 天然气工业,2022,42(1):83−92.

JIA Ailin,WEI Yunsheng,GUO Zhi,et al. Development status and prospect of tight sandstone gas in CHina[J]. Natural Gas Industry,2022,42(1):83−92.

[30] 陈刚,秦勇,胡宗全,等. 不同煤阶深煤层含气量差异及其变化规律[J]. 高校地质学报,2015,21(2):274−279.

CHEN Gang,QIN Yong,HU Zongquan,et al. Variations of Gas Content in Deep Coalbeds of Different Coal Ranks[J]. Geological Journal of China Universities,2015,21(2):274−279.

[31] 王艳,李伟峰,贾自力,等. 水平井水平段方位与最大主应力夹角对产能影响分析:以吴定地区水平井为例[J]. 非常规油气,2016,3(5):88−91.

WANG Yan,LI Weifeng,JIA Zili,et al. Influence of Included Angle between Horizontal Section of Horizontal Well and Main Stress on Productivity:Take Horizontal wells in Wuding Area for Example[J]. Unconventonal Oil & Gas,2016,3(5):88−91.

[32] TAO Shu,PAN Zhejun,TANG Shuling,et al. Current status and geological conditions for the applicability of CBM drilling technologies in China:A review[J]. International Journal of Coal Geology,2019,202:95−108.

[33] 胡秋嘉,李梦溪,贾慧敏,等. 沁水盆地南部高煤阶煤层气水平井地质适应性探讨[J]. 煤炭学报,2019,44(4):1178−1187.

HU Qiujia,LI Mengxi,JIA Huimin,et al. Discussion of the geological adaptability of coal-bed methane horizontal wells of high-rank coal formation in southern Qinshui Basin[J]. Journal of China Coal Society,2019,44(4):1178−1187.

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.