非生物成因天然气形成机制与资源前景  

Formation Mechanism and Resources Prospect of the Abiogenic Gas

作　　者：王先彬[1] 郭占谦 妥进才[1] 卓胜广[3] 李振西[1] 周世新[1] 闫宏[1] 

机构地区：[1]中国科学院地质与地球物理趼究所气体地球化学重点实验室 [2]大庆石油田勘探开发研究院 [3]东北大学秦皇岛分校

出　　处：《中国基础科学》2006年第4期12-20,共9页China Basic Science

基　　金：国家自然科学基金(No.49233060和No.40572087);973计划项目(2003CB214606)

摘　　要：本文论述了细菌(生物)成因气、热成因气、深层气和非生物成因气的形成机制和它们的耦合与差异;评述了非生物成因天然气的研究历史和发展态势,指出迄今在国际上因未发现任何具非生物成因特征的商业气藏,而认为非生物成因天然气不具有资源前景是一种错误结论。本文并讨论了地球深部有机质演化的关键科学问题和判识天然气成因类型地球化学指标的有效性,指出:沉积有机质受生物降解、热降解作用的同位素动力学分馏效应的制约,有机成因烷烃气体(甲烷、乙烷、丙烷和丁烷)的碳氢同位素δ13C值和δ2H值分布均呈正序分布,即:δ13C1<δ13C2<δ13C3<δ13C4和δ2HCH4<δ2HC2H6<δ2HC3H8<δ2HC4H10,二者具有正相关关系;非生物成因天然气受聚合作用同位素动力学分馏效应的制约,其烷烃气体的碳氢同位素分布则不同于前者,δ13C值呈反序分布δ13C1>δ13C2>δ13C3>δ13C4,而δ2H值呈正序分布δ2HCH4<δ2HC2H6<δ2HC3H8<δ2HC4H10,二者具有负相关关系;而且非生物成因甲烷的δ13C1≥-30.0‰。此外,本文评述了中国非生物成因天然气研究所取得的重要进展,论述了松辽盆地非生物成因天然气的地质地球化学特征,指出松辽盆地昌德肇州西非生物成因天然气藏的发现,为研究和寻找非生物成因天然气资源提供了典型实例;并指出伴随松辽盆地深层气勘探的重大突破,以及近20口商业天然气井非生物成因特征的确定,展现了松辽盆地非生物成因天然气勘探开发的良好前景,使松辽盆地成为世界上研究和寻找非生物成因天然气资源最理想的地区。The paper deals with formation mechanisms, correlations and differences of the bacterial （biogenic） gas, thermogenic gas, deep gas and abiogenic gas; evaluates the history and developmental tendency of abiogenic gas researches; debates upon the concept that the abiogenic gas has no resource prospect due to the absence of any abiogenic gas reservoirs with commercial value up to now in the world; and discusses the effectiveness of geochemical criteria to identify genetic types of natural gases as well as some key scientific problems on the organic matter evolution of the deep earth. It is proposed that controlled by the isotopically dynamic fractionation of biodegradation and thermal decomposition, the depositional organic matter produces hydrocarbon gases （methane, ethane, propane and butane） that have a normally ordered distribution for both carbon and hydrogen isotopic values, namely δ^13C1〈δ^13C2〈δ^13C3〈δ^13C4and δ^2HCH4〈δ^2HC2H6〈δ^2 HC3H8〈δ^2HC4H10 respectively, and hy showing a positive correlation between carbon drogen isotopes. However, the controlled by the isotopically dynamic abiogenic gas, fractionation of polymerization, has a reversed carbon but the same hydrogen isotopic distribution compared with biogenic gases,i.e.δ^13C1〉δ^13C2〉δ^13C3〉δ^13C4,and δ^2H4〈δ^2HC2H6〈δ^2HC3H8〈δ^2HC4H10 respectively, showing a negative correlation between carbon and hydrogen isotopes. Moreover, the abiogenie gas usually has δ^13C1 el values ≥-30.0‰. The paper also makes comments on the significant progress in abiogenic gas researches of China by means of depicting geological and geochemical characteristics of the abiogenic gas from Songliao Basin, and points that the discovery of the Changde-Zhaozhouxi abiogenic gas reservoir in Songliao Basin has provided studying and seeking abiogenic gas resources with an typical example： with the significant breakthrough in the deep gas exploration in Songliao Basin, more than 20 commercial wells are characteristic of an abiogenic

关 键 词：天然气形成机制 非生物成因气 地球化学判识指标 非生物成因气藏 非生物成因气资源前号 

分 类 号：P618.13[天文地球—矿床学] TE122.1[天文地球—地质学]