煤岩气成藏机理与煤系全油气系统  

Coal-rock gas accumulation mechanism and the whole petroleum system of coal measures

作　　者：李国欣 贾承造[1,5] 赵群 周天琪[3,5] 高金亮 LI Guoxin;JIA Chengzao;ZHAO Qun;ZHOU Tianqi;GAO Jinliang(China National Petroleum Corporation,Beijing 100007,China;PetroChina Company Limited,Beijing 100007,China;PetroChina Research Institute of Petroleum Exploration and Development,Beijing 100083,China;PetroChina Oil,Gas and New Energy Company,Beijing 100007,China;CNPC Key Laboratory of Coal-rock Gas,Langfang 065007,China)

机构地区：[1]中国石油天然气集团有限公司,北京100007 [2]中国石油天然气股份有限公司,北京100007 [3]中国石油勘探开发研究院,北京100083 [4]中国石油油气和新能源分公司,北京100007 [5]中国石油天然气集团有限公司煤岩气重点实验室,河北廊坊065007

出　　处：《石油勘探与开发》2025年第1期29-43,共15页Petroleum Exploration and Development

基　　金：中国石油天然气股份有限公司前瞻性基础性项目“煤岩气富集规律与开发机理研究”(2024DJ23);中国石油科学研究与技术开发项目“油气地质基础新理论新技术研究”项目01课题“全油气系统理论与非常规油气成藏机理”(2021DJ0101)。

摘　　要：煤系是含油气盆地重要的烃源岩和储集岩,国内外许多大型天然气田、煤层气田就由煤系烃源岩供气或在煤岩内储集成藏。受页岩油气探索实践的启发,按照“将煤岩作为储层整体勘探”的思路,在保存条件较好的深部煤岩内实现了煤岩气勘探开发突破,开辟了煤岩储层内非常规天然气发展的新领域。基于勘探开发实践资料,开展了煤岩气成藏机理的系统研究,揭示了“三场”控制成藏机理,明确了煤岩气与煤层气成藏作用的主要差异。分析了鄂尔多斯盆地东缘石炭纪—二叠纪海陆过渡相煤系全油气系统和准噶尔盆地侏罗纪陆相煤系全油气系统的特征,指出了进一步构建煤系全油气系统理论的重点研究方向。研究表明:煤岩与泥页岩相比存在强生烃、强吸附能力、双重介质,具备部分或较弱的油气自封闭作用等特征;煤岩气与页岩气、致密气等非常规天然气相比具有更复杂成藏作用等特殊性,成藏需要一定的煤岩组合形成封闭和岩性、构造圈闭,又具有常规裂缝气藏的特征。与以碎屑岩层系为典型建立的全油气系统基本理论和模式相比,煤系在煤岩储层和源储耦合上,具有明显的特点和差异。煤系全油气系统以煤系中煤岩(及暗色泥页岩)为烃源岩和储层,以及与其相邻的致密层为储层或盖层或输导层构成多种类型的煤系油气成藏组合,在源储耦合作用下,在保存条件较好的煤岩储层形成煤岩气,在致密层形成致密油气或在远源形成常规油气,在受后期地质作用破坏的煤岩储层形成煤层气,是一种新类型全油气系统。Coal measures are significant hydrocarbon source rocks and reservoirs in petroliferous basins.Many large gas fields and coalbed methane fields globally are originated from coal-measure source rocks or accumulated in coal rocks.Inspired by the discovery of shale oil and gas,and guided by“the overall exploration concept of considering coal rock as reservoir”,breakthroughs in the exploration and development of coal-rock gas have been achieved in deep coal seams with favorable preservation conditions,thereby opening up a new development frontier for the unconventional gas in coal-rock reservoirs.Based on the data from exploration and development practices,a systematic study on the accumulation mechanism of coal-rock gas has been conducted.The mechanisms of“three fields”controlling coal-rock gas accumulation are revealed.It is confirmed that the coal-rock gas is different from CBM in accumulation process.The whole petroleum systems in the Carboniferous–Permian transitional facies coal measures of the eastern margin of the Ordos Basin and in the Jurassic continental facies coal measures of the Junggar Basin are characterized,and the key research directions for further developing the whole petroleum system theory of coal measures are proposed.Coal rocks,compared to shale,possess intense hydrocarbon generation potential,strong adsorption capacity,dual-medium reservoir properties,and partial or weak oil and gas self-sealing capacity.Additionally,unlike other unconventional gas such as shale gas and tight gas,coal-rock gas exhibits more complex accumulation characteristics,and its accumulation requires a certain coal-rock play form lithological and structural traps.Coal-rock gas also has the characteristics of conventional fractured gas reservoirs.Compared with the basic theory and model of the whole petroleum system established based on detrital rock formations,coal measures have distinct characteristics and differences in coal-rock reservoirs and source-reservoir coupling.The whole petroleum system of coal meas

关 键 词：煤系 煤岩气 煤层气 致密气 煤岩组合 成藏机理 全油气系统 煤系全油气系统 

分 类 号：TE121.1[石油与天然气工程—油气勘探]