摘要
针对氦气成因来源、富集成藏和资源潜力,世界各国重视程度日益增加。多种类型地质体中氦气能否富集成藏的关键因素是氦气来源与储层之间的有效配置关系。本文系统梳理国内外不同构造背景和不同类型的富氦气藏基本特征,开展主要潜在氦源岩铀和钍含量测试与统计,并重点对鄂尔多斯盆地铝土岩层系富氦气藏进行解剖。在这些研究的基础上,明确了地质体中氦气主要来自壳源放射性成因氦和幔源氦。大规模高铀和钍含量的古老基底花岗岩/变质岩等氦源岩、有利的源储配置和氦气从源向储高效的运移疏导是世界上大型富氦气田形成的关键条件。氦气通常与CH_(4)、CO_(2)、N_(2)等在油气藏中呈共伴生关系。与N_(2)总体呈正相关关系,表明成因上有一定的联系;而与CO_(2)和CH_(4)呈负相关关系,表明CO_(2)和CH_(4)4的富集对氦气的稀释作用。依据富氦气藏氦源和储层之间的关系,分为内源型氦气藏、外源型氦气藏和复合型氦气藏。内源型氦气藏主要包括富氦页岩气藏,其中的氦气来自页岩本身所含有铀和钍衰变,与页岩有机质生成的天然气构成同源同储富氦气藏。外源型氦气藏主要包括常规碎屑岩和碳酸盐岩气藏,其中的氦气主要来自气藏储层之外的基底的壳源氦气或者幔源氦气。断裂沟通深部氦源,氦气通过水或者天然气携带运移至隆起高点位置的圈闭富集成为富氦气藏。铝土岩层系富氦气藏为混合型氦气藏,氦气即可来自古老基底,也可来自铝土岩层系的富铀和钍的铝土岩、泥页岩和煤岩;内源和外源的氦气与来自泥岩或煤层的烃类气体共同在铝土岩层系中富集成藏,形成异源同储的混合型氦气藏。
Countries worldwide are paying increasing attention to the origin,accumulation,and resource potential of helium.The key to understanding helium enrichment and accumulation in various types geological formations lies in the spatial relationships between helium sources and reservoirs.This paper systematically analyzed the characteristics of helium-rich gas reservoirs in diverse tectonic settings worldwide.We measured and summarized uranium and thorium content in main potential helium source rocks and conducted a detailed study of typical helium-rich gas reservoirs in the bauxite strata of the Ordos basin.Our findings indicate that helium in geological formations mainly originates from radiogenic helium of crustal origin and mantle helium.Large-scale helium source rocks,e.g.,ancient basement granite/metamorphic rocks with high uranium and thorium content,favorable source-reservoir configuration,and efficient helium migration from source to reservoir,are the key conditions for the formation of large-scale helium-rich gas fields around the world.Helium usually co-accumulates with natural gases such as CH_(4),CO_(2),and N_(2) in oil and gas reservoirs.Helium content shows a positive correlation with N_(2),suggesting a shared origin,while negative correlations with CO_(2) and CH_(4) indicate dilution effects on helium concentration.Based on the source-reservoir relationship,helium-rich gas reservoirs are divided into three types:endogenous,exogenous,and mixed.Endogenous helium reservoirs,which mainly include heliumrich shale gas reservoirs,derive helium from the decay of uranium and thorium contained in the shale itself.Helium and natural gas generated from organic matter in the shale constitute a reservoir with the same source and reservoir.Exogenous helium reservoirs,mainly conventional sandstone and carbonate gas reservoirs,receive helium from crustal helium or mantle helium in the basement outside the gas reservoir.Helium is transported by water or natural gas through faults connecting deep helium sources to uplift areas where it is enriched in a helium-rich gas reservoir.The helium-rich gas reservoir in the bauxite stratum is a mixed helium reservoir.Helium can come from exogenous ancient basement rocks or endogenous bauxite,mud shale,and coal rocks within the bauxite layers.Endogenous and exogenous helium,along with hydrocarbon gas from mudstone or coal source rocks,are jointly enriched and co-accumulated in the bauxite strata,forming a mixed helium reservoir with different sources in the same reservoir.
作者
朱东亚
刘全有
李朋朋
高宇
金晓辉
孟庆强
张军涛
吴小奇
ZHU Dongya;LIU Quanyou;LI Pengpeng;GAO Yu;JIN Xiaohui;MENG Qingqiang;ZHANG Juntao;WU Xiaoqi(National Energy Key Laboratory of Carbonate Oil and Gas,Beijing 102206,China;Petroleum Exploration and Production Research Institute,SINOPEC,Beijing 102206,China;Institute of Energy,Peking University,Beijing 100871,China)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2024年第11期3182-3201,共20页
Acta Geologica Sinica
基金
国家自然科学基金地质联合基金项目(编号U2244209)和氦气专项(编号42141021)
国家重点研发计划项目(编号2019YFA0708504)
中科院学部前沿交叉研判项目(编号XK2023DXA004)
中国石化石油勘探开发研究院项目(编号YK-2023-10)联合资助的成果。
关键词
富氦气藏
氦源岩
源储关系
铝土岩
异源同储
helium-rich gas reservoir
helium source rock
relationship between source and reservoir
bauxite reservoir
helium and gas from different source in same reservoir
