壳源富氦天然气藏潜在氦源岩主要特征及有效性分析  

Main characteristics and effectiveness analysis of potential helium source rock in crustal source helium-rich gas reservoirs

作　　者：赵栋[1,2] 王晓锋 刘文汇 张东东 李孝甫[1] ZHAO Dong;WANG Xiaofeng;LIU Wenhui;ZHANG Dongdong;LI Xiaofu(Department of Geology,State Key Laboratory of Continental Dynamics,Northzvest University,Xi'an 710069,China;Laboratory Management Office,Erperimental Center,Xi'an Shiyou University,X'an 710069,China;Petroleum Erploration and Production Research Institute,SINOPEC,Beijing 100083,China)

机构地区：[1]西北大学地质学系,大陆动力学国家重点实验室,陕西西安710069 [2]西安石油大学实验室管理处(实验中心),陕西西安710065 [3]中国石化石油勘探开发研究院,北京100083

出　　处：《天然气地球科学》2024年第3期507-517,共11页Natural Gas Geoscience

基　　金：国家自然科学基金项目(编号:42141022);国家自然科学基金项目(编号:42102203);国家重点研发计划“变革性技术关键科学问题”重点专项(编号:2021YFA0719002);中国博士后科学基金资助项目(编号:2022M712566)联合资助。

摘　　要：潜在氦源岩有效性评价是氦资源勘探开发领域关注的核心问题,但在以往的研究中,潜在氦源岩有效性评价多以岩石U、Th元素含量及年龄为主,未能全面表征影响氦源岩有效性的关键因素。为此,以花岗岩、泥页岩、片麻岩、铝土岩4种典型潜在氦源岩为研究对象,通过建立孔隙水累积溶解氦计算模型同时结合气藏实例,对各潜在氦源岩孔隙中溶解氦的累积、脱溶情况进行定量分析,从而对各潜在氦源岩有效性及有效氦源岩评价方法进行讨论与总结。研究认为:(1)潜在氦源岩孔隙中积累的溶解氦能否在适宜条件下规模性脱溶为游离氦是判识潜在氦源岩是否有效的关键性先决条件;(2)除岩石U、Th元素含量外,巨大的体量规模,适宜的孔隙度和含水饱和度,良好的“沉积埋藏史—气藏成藏史—构造演化史”时空匹配关系,以及相对专一的生氦能力也是评判潜在氦源岩有效性的关键参数;(3)通过建立溶解氦富集效率(η_(He))计算方法,认为在相同条件下花岗岩最易形成游离氦富集,泥页岩与铝土岩次之,片麻岩最难。The effectiveness evaluation of potential helium source rocks is a core issue in the field of helium resource exploration and development.However,in previous studies,the effectiveness evaluation of potential helium source rocks is mainly based on the content of U and Th elements and age of rock,which fails to fully characterize the key factors affecting the effectiveness of helium source rocks.Therefore,this paper takes four typical potential helium source rocks,namely granite,mud shale,gneisses and bauxite,as the research object.By establishing a calculation model for accumulated dissolved helium in pore water and combining with gas reservoir examples,the quantitative analysis of dissolved helium accumulation and exsolution in the pores of each potential helium source rock is carried out,so as to discuss and summarize the effectiveness of each potential helium source rock and the evaluation method of effective helium source rock.It is believed that:(1)Whether dissolved helium accumulated in the pores of potential helium source rocks can be exsolved into free helium on a large scale under suitable conditions is the key prerequisite for identifying the effectiveness of potential helium source rocks.(2)In addition to the content of U and Th elements,large volume,suitable porosity and water saturation,good matching relationship of"sedimentary and burial history,gas accumulation history and tectonic evolution history",and relatively specific helium generation ability are also the key parameters to judge the effectiveness of potential helium source rocks.(3)By establishing the calculation method of dissolved helium enrichment efficiency(η_(He)),it is concluded that under the same conditions,free helium enrichment is most easily formed in granite,followed by mud shale and bauxite,and gneiss is the most difficult.

关 键 词：壳源氦 有效氦源岩 溶解量 脱溶富集 富集效率 

分 类 号：TE122[石油与天然气工程—油气勘探]