Coal Geology & Exploration
Abstract
Objective China boasts abundant coalbed methane (CBM) resources, which serve as a crucial replacement for the reserve growth and production addition of natural gas resources. In recent years, CBM exploration and production have gradually expanded into deep, thin coal seams, which, however, are characterized by strong heterogeneity, ultra-low permeability, high in situ stress, and complex enrichment patterns. Therefore, the exploration and exploitation of deep, thin coal seams face challenges such as inadequate geological theories, poor adaptability of key technologies, and low investment returns, which hinder large-scale commercial CBM production. Methods Focusing on the exploration and exploitation practice of middle-deep, thin coal seams in the Yanchuannan CBM field within the Ordos Basin, this study systematically analyzed the geological characteristics of the CBM field, summarized the primary factors controlling CBM enrichment and high productivity, and established a series of geology-engineering integrated technologies for efficient exploration and exploitation of middle-deep, thin coal seams. Results The Yanchuannan CBM field contains two structural belts, namely Tanping and Wanbaoshan, which exhibit significantly different sedimentary environments, lithotypes and coal quality, reservoir quality, preservation conditions, and in situ stresses. Nevertheless, this CBM field generally shows middle-deep, undersaturated, low-temperature, low-pressure, thermogenic high-quality CBM reservoirs. The production characteristics of the CBM field are governed by fracturing performance. Specifically, gas wells subjected to conventional guided fracturing exhibit late gas shows and production addition combined with limited single-well productivity and recoverable reserves. In contrast, gas wells subjected to fracturing with fractures effectively propped demonstrate rapid production addition and high single-well productivity and recoverable reserves. By integrating dynamic and static analyses, this study gained a geological understanding of four-element coupling for the high productivity and enrichment of CBM in medium-deep coal seams, highlighting sedimentation-controlled coal distribution, preservation-controlled enrichment, in situ stress-controlled permeability, and effective stimulation-controlled productivity. An indicator system for the quantitative evaluation of geology-engineering “dual sweet spots” was developed to guide play fairway selection. Multi-scale pore-fracture characterization technology was established, enabling the quantitative characterization of reservoir spaces on the centimeter, millimeter, micrometer, and nanometer scales. The key technology based on geological modeling and numerical simulation integration ascertained the types and distribution patterns of residual gas. This technology can guide well pattern adjustments in residual gas enrichment zones, thus improving the production ratio and recovery of reserves. By highlighting the suitability of the well pattern and fracture networks, this study established a well pattern – fracture network – productivity – economic benefit integrated strategy tailored to varying geological conditions. To address challenges posed by thin coal seams and great structural fluctuations, this study established the horizontal well guidance – fracturing – production integrated technology for well completion in thin coal seams while considering the requirements of well drilling and completion, fracturing, and production. Through multiple rounds of research and iterative optimization based on a deepened understanding of coal properties, this study developed optimized fracturing with fractures effectively propped characterized by the preflush of high-volume fracturing fluids for longer fractures, variable injection rates of fracturing fluids for fracture height control, and multi-sized proppants for propping multi-scale fractures. The advancement in fracturing technologies shifted the production philosophy from slow and long-term drainage to optimal rapid production addition, leading to the formation of the production system characterized by four stages, two pressuring, and three controlling factors. A "node-region-center" three-level pressure boosting model was developed to maximize productivity. Conclusions Guided by these advancements, the Yanchuannan CBM field has achieved stable production growth and significantly increased single-well productivity, with the daily production of a single directional well increasing to 1×104 m³/d from 0.1 m³/d and that of a single horizontal well rising to (2.5‒6.0) × 104 m³/d from (0.5‒0.6) × 104 m³/d. These suggest effective fracturing performance and commercial production. This study serves as a valuable reference for the commercial production of similar deep, thin CBM resources in China.
Keywords
middle-deep coalbed methane (CBM), CBM from thin coal seams, Ordos Basin, Yanchuannan, enrichment high-productivity pattern, efficient exploration and exploitation, technological system
DOI
10.12363/issn.1001-1986.24.12.0758
Recommended Citation
HE Xipeng, XIAO Cui, GAO Yuqiao,
et al.
(2025)
"Geological characteristics and key technologies for exploration and development of the Yanchuannan coalbed methane field, Ordos Basin,"
Coal Geology & Exploration: Vol. 53:
Iss.
3, Article 6.
DOI: 10.12363/issn.1001-1986.24.12.0758
Available at:
https://cge.researchcommons.org/journal/vol53/iss3/6
Reference
[1] 吴裕根,门相勇,娄钰. 我国“十四五”煤层气勘探开发新进展与前景展望[J]. 中国石油勘探,2024,29(1):1−13.
WU Yugen,MEN Xiangyong,LOU Yu. New progress and prospect of coalbed methane exploration and development in China during the 14th Five–Year Plan period[J]. China Petroleum Exploration,2024,29(1):1−13.
[2] 樊大磊,王宗礼,李剑,等. 2023年国内外油气资源形势分析及展望[J]. 中国矿业,2024,33(1):30−37.
FAN Dalei,WANG Zongli,LI Jian,et al. Analysis of domestic and international oil and gas resources situation in 2023 and outlook[J]. China Mining Magazine,2024,33(1):30−37.
[3] 张宇,赵培荣,刘士林,等. 中国石化“十四五”主要勘探进展与发展战略[J]. 中国石油勘探,2024,29(1):14−31.
ZHANG Yu,ZHAO Peirong,LIU Shilin,et al. Main exploration progress and development strategy of Sinopec during the 14th Five–Year Plan period[J]. China Petroleum Exploration,2024,29(1):14−31.
[4] 桑树勋,韩思杰,周效志,等. 华东地区深部煤层气资源与勘探开发前景[J]. 油气藏评价与开发,2023,13(4):403−415.
SANG Shuxun,HAN Sijie,ZHOU Xiaozhi,et al. Deep coalbed methane resource and its exploration and development prospect in East China[J]. Petroleum Reservoir Evaluation and Development,2023,13(4):403−415.
[5] 何希鹏,汪凯明,罗薇,等. 四川盆地东南部南川地区煤层气地质特征及富集主控因素[J]. 石油实验地质,2025,47(1):64−76.
HE Xipeng,WANG Kaiming,LUO Wei,et al. Geological characteristics and main enrichment controlling factors of coalbed methane in Nanchuan area,southeastern Sichuan Basin[J]. Petroleum Geology & Experiment,2025,47(1):64−76.
[6] 徐凤银,王成旺,熊先钺,等. 鄂尔多斯盆地东缘深部煤层气成藏演化规律与勘探开发实践[J]. 石油学报,2023,44(11):1764−1780.
XU Fengyin,WANG Chengwang,XIONG Xianyue,et al. Evolution law of deep coalbed methane reservoir formation and exploration and development practice in the eastern margin of Ordos Basin[J]. Acta Petrolei Sinica,2023,44(11):1764−1780.
[7] 郭广山,徐凤银,刘丽芳,等. 鄂尔多斯盆地府谷地区深部煤层气富集成藏规律及有利区评价[J]. 煤田地质与勘探,2024,52(2):81−91.
GUO Guangshan,XU Fengyin,LIU Lifang,et al. Enrichment and accumulation patterns and favorable area evaluation of deep coalbed methane in the Fugu area,Ordos Basin[J]. Coal Geology & Exploration,2024,52(2):81−91.
[8] 张兵,杜丰丰,张海锋,等. 基于经济效益评价的煤层气开发有利区优选:以鄂尔多斯盆地东缘杨家坡区块为例[J]. 油气藏评价与开发,2024,14(6):933−941.
ZHANG Bing,DU Fengfeng,ZHANG Haifeng,et al. Selection of favorable areas for coalbed methane development based on economic benefit evaluation:A case study of Yangjiapo Block in eastern margin of Ordos Basin[J]. Petroleum Reservoir Evaluation and Development,2024,14(6):933−941.
[9] 徐凤银,聂志宏,孙伟,等. 鄂尔多斯盆地东缘深部煤层气高效开发理论技术体系[J]. 煤炭学报,2024,49(1):528−544.
XU Fengyin,NIE Zhihong,SUN Wei,et al. Theoretical and technological system for highly efficient development of deep coalbed methane in the eastern edge of Erdos Basin[J]. Journal of China Coal Society,2024,49(1):528−544.
[10] 姚红生,肖翠,陈贞龙,等. 延川南深部煤层气高效开发调整对策研究[J]. 油气藏评价与开发,2022,12(4):545−555.
YAO Hongsheng,XIAO Cui,CHEN Zhenlong,et al. Adjustment countermeasures for efficient development of deep coalbed methane in southern Yanchuan CBM Field[J]. Petroleum Reservoir Evaluation and Development,2022,12(4):545−555.
[11] 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.
[12] 申鹏磊,吕帅锋,白建平,等. 沁水盆地深部煤层气开发井完井技术进展[J/OL]. 煤炭科学技术,2024:1–12 [2024-04-09]. http://kns.cnki.net/kcms/detail/11.2402.TD.20240329.1742.001.html.
SHEN Penglei,LYU Shuaifeng,BAI Jianping,et al. Progress in the completion technology of deep coalbed methane development wells in the Qinshui Basin[J/OL]. Coal Science and Technology,2024:1–12 [2024-04-09]. http://kns.cnki.net/kcms/detail/11.2402.TD.20240329.1742.001.html.
[13] 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.
[14] 杨帆,李斌,王昆剑,等. 深部煤层气水平井大规模极限体积压裂技术:以鄂尔多斯盆地东缘临兴区块为例[J]. 石油勘探与开发,2024,51(2):389−398.
YANG Fan,LI Bin,WANG Kunjian,et al. Extreme massive hydraulic fracturing in deep coalbed methane horizontal wells:A case study of the Linxing Block,eastern Ordos Basin,NW China[J]. Petroleum Exploration and Development,2024,51(2):389−398.
[15] 安琦,杨帆,杨睿月,等. 鄂尔多斯盆地神府区块深部煤层气体积压裂实践与认识[J]. 煤炭学报,2024,49(5):2376−2393.
AN Qi,YANG Fan,YANG Ruiyue,et al. Practice and understanding of deep coalbed methane massive hydraulic fracturing in Shenfu Block,Ordos Basin[J]. Journal of China Coal Society,2024,49(5):2376−2393.
[16] 徐宝恒,郭大立. 大规模缝网压裂在深部煤层气中的应用[J]. 河南科技,2023,42(19):81−84.
XU Baoheng,GUO Dali. Application of large–scale fracture network fracturing in deep coalbed methane[J]. Henan Science and Technology,2023,42(19):81−84.
[17] 刘晓. 不同压裂规模下煤储层缝网形态对比研究:以延川南煤层气田为例[J]. 油气藏评价与开发,2024,14(3):510−518.
LIU Xiao. Comparison of seam network morphology in coal reservoirs under different fracturing scales:A case of Yanchuannan CBM Gas Field[J]. Petroleum Reservoir Evaluation and Development,2024,14(3):510−518.
[18] 曾雯婷,徐凤银,张雷,等. 鄂尔多斯盆地东缘深部煤层气排采工艺技术进展与启示[J]. 煤田地质与勘探,2024,52(2):23−32.
ZENG Wenting,XU Fengyin,ZHANG Lei,et al. Deep coalbed methane production technology for the eastern margin of the Ordos Basin:Advances and their implications[J]. Coal Geology & Exploration,2024,52(2):23−32.
[19] 曾雯婷,葛腾泽,王倩,等. 深层煤层气全生命周期一体化排采工艺探索:以大宁–吉县区块为例[J]. 煤田地质与勘探,2022,50(9):78−85.
ZENG Wenting,GE Tengze,WANG Qian,et al. Exploration of integrated technology for deep coalbed methane drainage in full life cycle:A case study of Daning–Jixian Block[J]. Coal Geology & Exploration,2022,50(9):78−85.
[20] 祁炜,孙龙飞,杨林,等. 大吉区块深层煤层气水平井排水采气技术研究与应用[J]. 中国石油和化工标准与质量,2024,44(5):182−184
[21] 吴壮坤,张宏录,池宇璇,等. 新型排采泵在延川南深层煤层气井的改进及应用[J]. 油气藏评价与开发,2023,13(4):416−423.
WU Zhuangkun,ZHANG Honglu,CHI Yuxuan,et al. Improvement and application of a novel drainage pump of deep coalbed methane wells in south Yanchuan[J]. Petroleum Reservoir Evaluation and Development,2023,13(4):416−423.
[22] 何希鹏,张培先,高玉巧,等. 中国非常规油气资源效益开发面临的挑战与对策[J]. 中国石油勘探,2025,30(1):26−41.
HE Xipeng,ZHANG Peixian,GAO Yuqiao,et al. Challenges and countermeasures for beneficial development of unconventional oil and gas resources in China[J]. China Petroleum Exploration,2025,30(1):26−41.
[23] 肖翠,陈贞龙,金晓波. 延川南煤层气田煤体结构模式及改造效果分析[J]. 煤炭科学技术,2021,49(11):38−46.
XIAO Cui,CHEN Zhenlong,JIN Xiaobo. Coal structure model and fracturing effect of Yanchuannan coalbed gas field[J]. Coal Science and Technology,2021,49(11):38−46.
[24] 郭伟. 延川南煤层气田基本特征与成藏关键因素[J]. 石油实验地质,2015,37(3):341−346.
GUO Wei. Basic characteristics and key factors of gas accumulation in Yanchuannan coalbed gas field[J]. Petroleum Geology & Experiment,2015,37(3):341−346.
[25] 王赛英. 鄂尔多斯盆地延川南地区煤储层特征研究[D]. 成都:成都理工大学,2011.
WANG Saiying. Study on features of coal reservoir of southern Yanchuan Block of Ordos Basin[D]. Chengdu:Chengdu University of Technology,2011.
[26] 王松. 鄂尔多斯盆地延川南地区上古生界沉积相与古地理演化研究[D]. 成都:成都理工大学,2018.
WANG Song. Sedimentary facies and paleogeographic evolution of Upper Paleozoic in southern Yanchuan,Ordos Basin[D]. Chengdu:Chengdu University of Technology,2018.
[27] 王峻,张航,曾令平. 延川南地区含煤地层沉积环境分析[J]. 煤炭技术,2015,34(12):116−118.
WANG Jun,ZHANG Hang,ZENG Lingping. Analysis of sedimentary environment of coal bearing strata in southern Yanchuan[J]. Coal Technology,2015,34(12):116−118.
[28] 杨秀春,徐凤银,王虹雅,等. 鄂尔多斯盆地东缘煤层气勘探开发历程与启示[J]. 煤田地质与勘探,2022,50(3):30−41.
YANG Xiuchun,XU Fengyin,WANG Hongya,et al. Exploration and development process of coalbed methane in eastern margin of Ordos Basin and its enlightenment[J]. Coal Geology & Exploration,2022,50(3):30−41.
[29] 李永. 浅谈煤层气藏保存条件[J]. 华北国土资源,2008(2):20−21
[30] 李鑫. 构造对深层煤层气井产能的控制研究[J]. 油气藏评价与开发,2021,11(4):643−651.
LI Xin. Structural control on productivity of deep coalbed methane wells[J]. Petroleum Reservoir Evaluation and Development,2021,11(4):643−651.
[31] 闫霞,徐凤银,聂志宏,等. 深部微构造特征及其对煤层气高产“甜点区”的控制:以鄂尔多斯盆地东缘大吉地区为例[J]. 煤炭学报,2021,46(8):2426−2439.
YAN Xia,XU Fengyin,NIE Zhihong,et al. Microstructure characteristics of Daji area in east Ordos Basin and its control over the high yield dessert of CBM[J]. Journal of China Coal Society,2021,46(8):2426−2439.
[32] 孙粉锦,王勃,李梦溪,等. 沁水盆地南部煤层气富集高产主控地质因素[J]. 石油学报,2014,35(6):1070−1079.
SUN Fenjin,WANG Bo,LI Mengxi,et al. Major geological factors controlling the enrichment and high yield of coalbed methane in the southern Qinshui Basin[J]. Acta Petrolei Sinica,2014,35(6):1070−1079.
[33] 宋岩,马行陟,柳少波,等. 沁水煤层气田成藏条件及勘探开发关键技术[J]. 石油学报,2019,40(5):621−634.
SONG Yan,MA Xingzhi,LIU Shaobo,et al. Gas accumulation conditions and key exploration & development technologies in Qinshui coalbed methane field[J]. Acta Petrolei Sinica,2019,40(5):621−634.
[34] 李勇. 鄂尔多斯盆地东缘煤层气富集成藏规律研究[D]. 北京:中国地质大学(北京),2015.
LI Yong. Coalbed methane accumulation and reservoring in east margin of Ordos Basin,China[D]. Beijing:China University of Geosciences(Beijing),2015.
[35] 路艳军. 煤岩体积压裂机理研究[D]. 成都:西南石油大学,2015.
LU Yanjun. Mechanism researches of stimulated reservoir volume in coal seams[D]. Chengdu:Southwest Petroleum University,2015.
[36] 刘大锰,贾奇锋,蔡益栋. 中国煤层气储层地质与表征技术研究进展[J]. 煤炭科学技术,2022,50(1):196−203.
LIU Dameng,JIA Qifeng,CAI Yidong. Research progress on coalbed methane reservoir geology and characterization technology in China[J]. Coal Science and Technology,2022,50(1):196−203.
[37] 仝少凯,高德利,岳艳芳. 弯曲连续管内流体运动机理与摩阻研究[J]. 石油机械,2020,48(3):134−139.
TONG Shaokai,GAO Deli,YUE Yanfang. Motion mechanism and friction analysis of fluid flow in the curved coiled tubing[J]. China Petroleum Machinery,2020,48(3):134−139.
[38] 李天才,郭建春,赵金洲. 压裂气井支撑剂回流及出砂控制研究及其应用[J]. 西安石油大学学报(自然科学版),2006,21(3):44−47.
LI Tiancai,GUO Jianchun,ZHAO Jinzhou. Study on the proppant backflow control and the sanding control of fractured gas wells and its application[J]. Journal of Xi’an Shiyou University (Natural Science Edition),2006,21(3):44−47.
[39] 姚红生,陈贞龙,郭涛,等. 延川南深部煤层气地质工程一体化压裂增产实践[J]. 油气藏评价与开发,2021,11(3):291−296.
YAO Hongsheng,CHEN Zhenlong,GUO Tao,et al. Stimulation practice of geology–engineering integration fracturing for deep CBM in Yanchuannan Field[J]. Petroleum Reservoir Evaluation and Development,2021,11(3):291−296.
[40] 王伟光. 马必东区块煤层气产能影响因素及传质过程[D]. 北京:中国地质大学(北京),2020.
WANG Weiguang. Factors affecting gas production capacity of coalbed methane wells and transfer process mechanism in Mabidong Block[D]. Beijing:China University of Geosciences(Beijing),2020.
[41] 陈贞龙. 解吸阶段划分对延川南煤层气田开发的指示意义[J]. 油气藏评价与开发,2017,7(5):80−84.
CHEN Zhenlong. The significance of desorption phase division on the development of coalbed methane fields in southern Yanchuan County[J]. Reservoir Evaluation and Development,2017,7(5):80−84.
[42] 孟艳军,汤达祯,许浩,等. 煤层气解吸阶段划分方法及其意义[J]. 石油勘探与开发,2014,41(5):612−617.
MENG Yanjun,TANG Dazhen,XU Hao,et al. Division of coalbed methane desorption stages and its significance[J]. Petroleum Exploration and Development,2014,41(5):612−617.
[43] 王志永,李岳栋,牛大玮. 煤层气低压集输工艺技术应用研究[J]. 中国设备工程,2021(增刊1):127−129.
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