Theory, technology, exploration and development progress and prospects of coal-rock gas in China

doi:10.3969/j.issn.1672-7703.2025.04.001

Abstract

Abstract: Coal-rock gas is a new type of unconventional natural gas resource. In recent years, strategic breakthrough has been achieved,
which has great significance for ensuring energy security in China. The research progress in geological theories, key technologies, and current status of exploration and development of coal-rock gas are systematically discussed, and the development prospects are put forward based on resource potential analysis results. The study results show that: (1) A consensus has basically been reached in the industry on the connotation of coal-rock gas. The coal rock shows a typical dual-pore media reservoir. Coal-rock gas is composed of complex gas components and high content of free gas, which has characteristics of migration and accumulation, and good preservation conditions are required for the formation of effective gas reservoir. (2) The understanding of coal-rock gas accumulation mechanism and the theoretical framework of whole petroleum system of coal measures have primarily been established, forming a “three-field controlling” coal-rock gas accumulation mechanism, and two types of gas accumulation and enrichment models, i.e., “integration of source rock and reservoir, and box-type sealing” and “multi-source supply, and gas enrichment in reservoir at high structural parts”. (3) A series of technologies have initially been developed, such as coa-rock gas resource assessment, geological and engineering sweet spot evaluation, laboratory testing, horizontal well multi-stage fracturing, production capacity evaluation, and production optimization. In addition, technologies such as water-reducing/water-free reservoir reconstruction and stereoscopic development of multi-layer and multi-source gas in coal measures are actively being researched. These technologies have supported the cumulative proven coa-rock gas geological reserves of 5968×10⁸ m³ , and the output reaching 27×10⁸ m³ in 2024. (4) It is preliminarily estimated that the coal-rock gas geological resources exceed 38×10¹² m³, possessing the resource foundation for
achieving an annual output of 300×10⁸ m³ by 2035, which shows a new growth point in the natural gas industry. (5) Three major challenges in coal-rock gas exploration and development are pointed out, and six key theoretical and technological research directions are proposed to promote the high-quality development of coal-rock gas industry in the future.

Key words: coal-rock gas, geological characteristics, gas accumulation theory, whole petroleum system in coal measures, exploration and
development, resource potential, development prospect

CLC Number:

TE122.1

Li Guoxin, He Xinxing, Zhao Qun, Zhang Junfeng, Zhang Guosheng, Zhang Lei, Xu Wanglin, Zhang Bin, Yang Zhi. Theory, technology, exploration and development progress and prospects of coal-rock gas in China[J]. China Petroleum Exploration, 2025, 30(4): 1-17.

References

[1] 李国欣，张品先，孙贤胜，等. 前行之路：复杂世界的能源战略：2025 年剑桥能源周主要观点[J]. 国际石油经济，2025,33(5):1-9,102.
Li Guoxin, Zhang Pinxian, Sun Xiansheng, et al . Moving ahead:energy strategies for a complex world: key insights from CERAWeek 2025 [J]. International Petroleum Economics,2025,33(5):1-9,102.
[2] 李国欣，张水昌，何海清，等. 煤岩气：概念、内涵与分类标准[J].石油勘探与开发，2024,51(4):783-795.
Li Guoxin, Zhang Shuichang, He Haiqing, et al . Coalrock gas: concept, connotation and classification criteria [J]. Petroleum Exploration and Development, 2024,51(4):783-795.
[3] 郭绪杰，支东明，毛新军，等. 准噶尔盆地煤岩气的勘探发现及意义[J]. 中国石油勘探，2021,26(6):38-49.
Guo Xujie, Zhi Dongming, Mao Xinjun, et al . Discovery and significance of coal measure gas in Junggar Basin [J]. China Petroleum Exploration, 2021,26(6):38-49.
[4] Code of Federal Regulations: Natural Gas Act, 18 CFR[EB/OL].[2025-06-21].https://tile.loc.gov/storage-services/service/ll/cfr/cf/r1/94/00/03/-T/18/CI/P2/50/cfr1940003-T18CIP250/cfr1940003-T18CIP250.pdf.
[5] History of WV mineral industries - oil and gas, by west virginia geological and economic survey[EB/OL].[2025-06-21]. https://cyclingscenicwv.com/Wirt/O&GInfo.pdf.
[6] Dugan T A, Williams B L. History of Gas Produced from Coal Seams in the San Juan Basin[M]// Geology and Coal-bed Methane Resources of the Northern San Juan Basin, Colorado and New Mexico, Fassett J E, ed. 1988:1-10.
[7] U.S. Department of the Interior, Minerals Management Service, Gulf of Mexico OCS Region. DOE’s Unconventional Gas Research Programs 1976-1995 [EB/OL]. [2025-06-21]. https://geographic.org/unconventional_gas_research/eastern_gas.html.
[8] Zuber M D, Boyer C M II. Comparative analysis of coalbed methane production trends and variability—impact on exploration and production[C]. Alabama:Proc., Intl. Coalbed Methane Symposium, 2001:245-256.
[9] U.S. Energy Information Administration. Technically recoverable shale oil and shale gas resources: an assessment of 137shale formations in 41 countries outside the United States[EB/OL].(2013-06-30)[2025-06-21].https://www.eia.gov/analysis/studies/worldshalegas/pdf/overview.pdf.
[10] 傅雪海，张宝鑫，康俊强.“煤岩气”概念的探讨与辨析[J]. 天然气工业，2025,45(3):46-53.
Fu Xuehai, Zhang Baoxin, Kang Junqiang. Discussion and analysis on the concept of“coal-rock gas”[J]. Natural Gas Industry, 2025,45(3):46-53.
[11] 胡文瑞. 煤岩气一种值得高度重视的新类型非常规天然气[J]. 石油知识，2025(2):9-11,69.
Hu Wenrui. Coalbed methane is a new type of unconventional natural gas that deserves great attention [J]. Petroleum Knowledge, 2025(2):9-11,69.
[12] 周立宏，熊先钺，丁蓉，等. 煤岩气内涵、富集机理及实践意义[J].天然气工业，2025,45(3):1-15.
Zhou Lihong, Xiong Xianyue, Ding Rong, et al . Connotation, enrichment mechanism and practical significance of coal-rock gas [J]. Natural Gas Industry, 2025,45(3):1-15.
[13] 邹才能，赵群，刘翰林，等. 中国煤岩气突破及意义[J]. 天然气工业，2025,45(4):1-18.
Zou Caineng, Zhao Qun, Liu Hanlin, et al . China’s breakthrough in coal-rock gas and its significance [J]. Natural Gas Industry, 2025,45(4):1-18.
[14] 李国欣，贾承造，赵群，等. 煤岩气成藏机理与煤系全油气系统[J].石油勘探与开发，2025,52(1):29-43.
Li Guoxin, Jia Chengzao, Zhao Qun, et al . Coal-rock gas accumulation mechanism and the whole petroleum system of coal measures [J]. Petroleum Exploration and Development, 2025,52(1):29-43.
[15] 毛新军，李艳平，梁则亮，等．准噶尔盆地侏罗系煤岩气成藏条件及勘探潜力[J]. 中国石油勘探，2024,29(4):31-43.
Mao Xinjun, Li Yanping, Liang Zeliang, et al . Hydrocarbon accumulation conditions and exploration potential of the Jurassic coal measure gas in Junggar Basin [J]. China Petroleum Exploration, 2024,29(4):31-43.
[16] 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.
[17] 赵喆，徐旺林，赵振宇，等. 鄂尔多斯盆地石炭系本溪组煤岩气地质特征与勘探突破[J]. 石油勘探与开发，2024,51(2):234-247,259.
Zhao Zhe, Xu Wanglin, Zhao Zhenyu, et al . Geological characteristics and exploration breakthroughs of coal rock gas in Carboniferous Benxi Formation, Ordos Basin, NW China [J]. Petroleum Exploration and Development, 2024,51(2):234-247,259.
[18] 郭旭升，周德华，赵培荣，等. 鄂尔多斯盆地石炭系—二叠系煤系非常规天然气勘探开发进展与攻关方向[J]. 石油与天然气地质，2022,43(5):1013-1023.
Guo Xusheng, Zhou Dehua, Zhao Peirong, et al . Progresses and directions of unconventional natural gas exploration and development in the Carboniferous-Permian coal measure strata, Ordos Basin [J]. Oil and Gas Geology, 2022,43(5):1013-1023.
[19] 钱大都，魏斌贤，李钰，等. 中国煤炭资源总论[M]. 北京：地质出版社，1996.
Qian Dadu, Wei Binxian, Li Yu, et al . Overview of China’s coal resources [M]. Beijing: Geological Publishing House, 1996.
[20] 叶建平，岳魏，秦勇，等. 中国煤层气聚集区带划分[J]. 天然气工业，1999,19(5):9-12.
Ye Jianping, Yue Wei, Qin Yong, et al . Division of coalbed gas accumulation regions and zones in China [J]. Natural Gas
Industry, 1999,19(5):9-12.
[21] 孙粉锦，周国晓，田文广，等. 煤层气系统的定义、内涵、形成及应用：以鄂尔多斯盆地石炭系—二叠系煤层为例[J]. 天然气工业，2024,44(7):42-53.
Sun Fenjin, Zhou Guoxiao, Tian Wenguang, et al . Definition, connotation, formation and application of coalbed methane system: a case study on the Carboniferous-Permian coal seams in the Ordos Basin [J]. Natural Gas Industry, 2024,44(7):42-53.
[22] Scott A R. Composition and origin of coalbed gases from seleted basins in the united states[C]//Proceeding of the 1993
International Coalbed Methane Symposium. Birmingham, Alabama, 1993: 207-212.
[23] Kuuskraa V A , Wyman R E. Deep coal seams: an overlooked source for long-term natural gas supplies [C]. SPE Gas Technology Symposium, 1993.
[24] 贾承造. 论非常规油气对经典石油天然气地质学理论的突破及意义[J]. 石油勘探与开发，2017,44(1):1-11.
Jia Chengzao. Breakthrough and significance of unconventional oil and gas to classical petroleum geological theory [J]. Petroleum
Exploration and Development, 2017,44(1):1-11.
[25] 贾承造，郑民，张永峰. 非常规油气地质学重要理论问题[J]. 石油学报，2014,35(1):1-10.
Jia Chengzao, Zheng Min, Zhang Yongfeng. Four important theoretical issues of unconventional petroleum geology [J]. Acta
Petrolei Sinica, 2014,35(1):1-10.
[26] 贾承造，庞雄奇，宋岩. 全油气系统理论基本原理[J]. 石油勘探与开发，2024,51(4):679-691.
Jia Chengzao, Pang Xiongqi, Song Yan. Basic principles of the whole petroleum system [J]. Petroleum Exploration and Development, 2024,51(4):679-691.
[27] 张君峰，李国欣，贾承造，等. 煤系全油气系统中天然气类型与煤岩气分类研究[J]. 石油勘探与开发，2025,52(4):792-803.
Zhang Junfeng, Li Guoxin, Jia Chengzao, et al . Natural gas types and coal rock gas classification in the whole petroleum system of coal measures [J]. Petroleum Exploration and Development, 2025,52(4):792-803.
[28] 闫霞，熊先钺，李曙光，等. 深层煤岩气水平井各段产出贡献及其主控因素：以鄂尔多斯盆地东缘大宁—吉县区块为例[J]. 天然气工业，2024,44(10):80-92.
Yan Xia, Xiong Xianyue, Li Shuguang, et al . Production contributions of deep CBM horizontal well sections and their controlling factors: a case study of Daning-Jixian area, eastern Ordos Basin [J]. Natural Gas Industry, 2024,44(10):80-92.
[29] 刘洪涛，曹振义，郝鹏程，等. 鄂尔多斯盆地东缘深层煤岩气水平井钻井关键技术[J]. 钻采工艺，2025,48(3):48-55.
Liu Hongtao，Cao Zhenyi，Hao Pengcheng，et al . Key technologies for drilling deep coal rock gas horizontal wells in the eastern margin of the Ordos Basin [J]. Drilling and Production Technology, 2025,48(3):48-55.
[30] 朱庆忠，熊伟，翁定为，等. 聚能压裂开发技术理论及实践[J]. 石油勘探与开发，2025,52(3):665-676.
Zhu Qingzhong, Xiong Wei, Weng Dingwei, et al . Theory and practice of energy-focused fracturing development technology [J].
Petroleum Exploration and Development, 2025,52(3):665-676.
[31] 王红岩，段瑶瑶，刘洪林，等. 煤层气水平井开发的理论技术初探[J].煤田地质与勘探，2024,52(4):47-59.
Wang Hongyan, Duan Yaoyao, Liu Honglin, et al . Preliminarily exploring the theories and technologies for coalbed methane production suing horizontal wells: comparison of conditions for coalbed methane and shale gas explortation [J]. Coal Geology and Exploration, 2024,52(4):47-59.
[32] 王在明，陈金霞，沈园园，等.JN1H 井煤岩气长水平段钻井井壁稳定技术[J]. 钻井液与完井液，2023,40(3):356-362.
Wang Zaiming, Chen Jinxia, Shen Yuanyuan, et al . Borehole wall stabilization technology for drilling the long horizontal section Coal Rock Gas well JN1H [J]. Drilling Fluid and Completion Fluid, 2023,40(3):356-362.
[33] 王高成，田文广，章超，等. 四川盆地大安区块深层煤岩气储层特征及勘探潜力[J]. 天然气工业，2025,45(3):68-81.
Wang Gaocheng, Tian Wenguang, Zhang Chao, et al . Reservoir characteristics and exploration potential of deep CBM in the Da’an Block, Sichuan Basin [J]. Natural Gas Industry,2025,45(3):68-81.
[34] 张君峰，毕彩芹，汤达祯，等. 中国煤层气勘探开发探索与实践[M].北京：地质出版社，2020.
Zhang Junfeng, Bi Caiqin, Tang Dazhen, et al . Research and practice of coalbed methane exploration and development in China [M]. Beijing: Geological Publishing House, 2020.
[35] 支东明，李建忠，杨帆，等. 吐哈盆地台北凹陷侏罗系煤系全油气系统特征[J]. 石油勘探与开发，2024,51(3):453-466.
Zhi Dongming, Li Jianzhong, Yang Fan, et al . Whole petroleum system in Jurassic coal measures of Taibei Sag in Tuha Basin,
NW China [J]. Petroleum Exploration and Development, 2024,51(3):453-466.
[36] 孙钦平，赵群，姜馨淳，等. 新形势下中国煤层气勘探开发前景与对策思考[J]. 煤炭学报，2021,46(1):65-76.

Sun Qinping, Zhao Qun, Jiang Xinchun, et al . Prospects and strategies of CBM exploration and development in China under

the new situation [J]. Journal of China Coal Society, 2021,46(1):65-76.
[37] 徐凤银，侯伟，熊先钺，等. 中国煤层气产业现状与发展战略[J]. 石油勘探与开发，2023,50(4):669-682.
Xu Fengyin, Hou Wei, Xiong Xianyue, et al . The status and development strategy of coalbed methane industry in China [J]. Petroleum Exploration and Development, 2023,50(4):669-682.
[38] 李彦忱，刘杰，王箴. 煤层气产量预测分析决策支持系统在上下游一体化项目生产管理中的应用[J]. 石油科技论坛，2024,43(3):104-111.
Li Yanchen, Liu Jie, Wang Zhen. Application of analysis and decision-making support system of CSG production forecast in
production management of upstream and downstream integration projects [J]. Petroleum Science and Technology Forum,
2024,43(3):104-111.
[39] 沈柏坪，李荣相，白洪涛，等. 鄂尔多斯盆地宜川地区本溪组8 号煤岩特征及成煤环境分析[J]. 特种油气藏，2024,31(6):32-38.
Shen Baiping, Li Rongxiang, Bai Hongtao, et al . Analysis of coal rock characteristics and coal-forming environment of the No.8 coal seam in the Benxi Formation in Yichuan Area, Ordos Basin[J].Special Oil & Gas Reservoirs, 2024,31(6):32-38.
[40] 罗平亚，朱苏阳. 中国建立千亿立方米级煤层气大产业的理论与技术基础[J]. 石油学报，2023,44(11):1755-1763.
Luo Pingya, Zhu Suyang. Theoretical and technical fundamentals of a 100 billion-cubic-meter-scale large industry of coalbed methane in China [J]. Acta Petrolei Sinica, 2023, 44(11):1755-1763.