天然氢气规模生成的成因类型与成藏特点  

Origins and accumulation characteristics of large-scale generation of natural hydrogen

作　　者：尹路[1] 李博 齐雯[1] 孙东[1] 乐幸福[1] 马慧 YIN Lu;LI Bo;QI Wen;SUN Dong;YUE Xingfu;MAHui(PetroChina Research Institute of Petroleum Exploration and Development-Northwest,Lanzhou 730020,China)

机构地区：[1]中国石油勘探开发研究院西北分院

出　　处：《岩性油气藏》2024年第6期1-11,共11页Lithologic Reservoirs

基　　金：中国石油天然气股份有限公司两性项目“天然氢形成富集机制与勘查技术研究”(编号:2024DJ9303);中国石油勘探开发研究院西北分院项目“天然氢成因机制研究及我国勘探有利区优选”(编号:xbky24-01)联合资助。

摘　　要：目前对全球天然氢气资源的估量十分巨大,寻找天然氢气的规模聚集区有赖于对其形成机理和富集规律的不断认识。通过对国内外典型天然氢气显示的数据统计,系统总结了全球天然氢气规模聚集的成因类型、并分析了天然氢气藏的分布和成藏特征。研究结果表明:①天然氢气的成因复杂多样,主要包括水岩反应、地幔脱氢、水的辐解、岩石破碎、有机质热解以及微生物作用等,其中,水岩反应生氢和地幔脱气生氢在自然界中普遍发生,在各种地质环境中广泛存在,且其生氢速率高、生氢量大,因此是天然氢气规模生成最重要的2种成因类型。②天然氢气藏的赋存环境集中体现于三大地质背景中:板块俯冲带、前寒武纪富铁地层发育区以及裂谷构造系统。③天然氢气藏的盖层条件受多个因素的影响,不仅要考虑盖层本身的封盖能力,还要考虑由于氢活跃的物理化学性质导致盖层机械性能发生的变化,影响其脆性-韧性行为形成新的裂缝而产生氢气的逃逸。④地下微生物利用氢气进行代谢活动、中深层的加氢生烃作用等耗烃作用不利于氢气规模聚集,因此在寻找天然氢气生成有利区时,应该避开氢被大量消耗的区域。⑤天然氢气的生成时间尺度短和易扩散性等因素,使得天然氢气成藏表现出动态成藏的特征,只要氢生成与散失始终处于一种动态平衡,就能够富集成藏。地下水是水岩反应生氢的必要条件,国外发现的很多天然氢气藏都分布在地下水循环较好的地区。At present,the estimation of global natural hydrogen resources is enormous,and the understanding of its formation mechanism and enrichment rules is helpful for searching for large-scale accumulation areas of natural hydrogen.Through the statistical analysis of typical natural hydrogen displays both domestically and internationally,the origin types of large-scale accumulation of global natural hydrogen gas were summarized,and the distribution and accumulation characteristics of natural hydrogen gas reservoirs were analyzed.The results show that:(1)The origin of natural hydrogen is complex,mainly including water-rock reactions,degassing of deep-seated hydrogen from the mantle,water radiolysis,rock fragmentation,decomposition of organic matter,and biological activity.Among them,hydrogen generation through water-rock reactions and degassing of deep-seated hydrogen from the mantle are commonly occurring in nature,and widely present in various geological environments,with high hydrogen generation rates and large amounts.Therefore,they are the two most important origin types for the large-scale generation of natural hydrogen.(2)The natural hydrogen gas reservoirs are mainly developed in three geological backgrounds:plate subduction zones,pre-Cambrian iron-rich strata development areas,and rift tectonic systems.(3)The sealing conditions of natural hydrogen reservoirs are affacted by multiple factors,including not only the sealing ability of the cap rocks,but also the changes in the mechanical properties of the cap rocks caused by the active physical and chemical properties of hydrogen,which affect its brittleness-toughness and form fractures,resulting in the escape of hydrogen.(4)Metabolic activities of underground microorganisms by hydrogen,and hydrocarbon generation in the middle and deep layers are not conducive to the large-scale accumulation of hydrogen.Therefore,when searching for favorable areas for natural hydrogen generation,areas where hydrogen is consumed in large quantities should be avoided.(5)Due to factors

关 键 词：天然氢气 水岩反应 地幔脱氢 板块俯冲带 前寒武纪条带状铁建造 裂谷构造系统 规模生成 成藏特征 

分 类 号：TE122.2[石油与天然气工程—油气勘探] P618.13[天文地球—矿床学]