鄂尔多斯盆地庆阳气田潜在氦源岩有效性评价  

Effectiveness evaluation of potential helium source rocks in Qingyang Gas Field,Ordos Basin

作　　者：康锐[1,2] 范立勇[1,2] 惠洁 李小燕 马晓峰 唐敏 郝乐伟 KANG Rui;FAN Liyong;HUI Jie;LI Xiaoyan;MA Xiaofeng;TANG Min;HAO Lewei(Research Institute of Exploration and Development,PetroChina Changqing Oilfield Company,Xi’an 710018,China;National Engineering Laboratory for Exploration and Development of Low-Permeability Oil&Gas Fields,Xi’an 710018,China;Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences,Lanzhou 730000,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国石油长庆油田分公司勘探开发研究院,陕西西安710018 [2]低渗透油气田勘探开发国家工程实验室,陕西西安710018 [3]中国科学院西北生态环境资源研究院,甘肃兰州730000 [4]中国科学院大学,北京100049

出　　处：《天然气地球科学》2025年第3期413-429,共17页Natural Gas Geoscience

基　　金：中国石油天然气股份有限公司关键核心项目“氦气资源评价与低成本提氦及运储关键技术研究”(编号:2021ZG13)资助.

摘　　要：氦源岩是形成富氦气藏的物质基础,是氦气资源勘探中的关键研究内容之一,目前对于氦源岩的评价比较薄弱,还需进行深入系统的研究。通过对鄂尔多斯盆地庆阳气田发育的潜在氦源岩开展铀钍含量、铀钍赋存状态、富铀钍矿物类型及大小、氦气释放方式和地质作用等系统分析,结合不同氦源岩之间的对比,对该区潜在氦源岩有效性进行评价。结果表明:研究区铝土岩的U和Th含量最高,硅质岩的最少。泥岩、煤、白云岩和硅质岩等的铀钍元素以吸附为主或者赋存在较小重矿物中,产生的氦气以衰变反冲的方式释放,具有连续释放的特点,而基底花岗片麻岩、铝土岩和砂岩的铀钍元素主要赋存在较大重矿物中,地层温度未超过封闭温度时,氦气在重矿物中积累,当异常高温突破了氦气在重矿物中的封闭温度时,积累的氦气会集中释放,具有“幕式释放”的特征。结合氦源岩发育的规模及U和Th含量,表明基底花岗片麻岩、泥岩、铝土岩和砂岩为研究区的主要氦源岩,白云岩、硅质岩和煤为次要氦源岩。在早白垩世,研究区天然气大规模成藏,此时氦气在异常高温的作用下大量释放脱离源岩与天然气耦合成藏。Helium source rocks are the material basis for the formation of helium rich gas reservoirs,and are one of the key research contents in helium resource exploration.At present,the evaluation of helium source rocks is relatively simple,and it is necessary to conduct intensive and systematic research on helium source rocks.Based on the systematic analysis of the potential helium source rocks in Qingyang Gas Field,Ordos Basin,including uranium and thorium content,uranium and thorium occurrence state,types and sizes of minerals enriched in ura⁃nium and thorium,helium release mode and geological process,and combined with the comparative study of dif⁃ferent helium source rocks,this paper evaluates the effectiveness of the potential helium source rocks in this ar⁃ea.The results show that the U and Th contents of potential helium source rocks in the study area are the high⁃est in bauxite and the lowest in siliceous rock.In mudstone,coal,dolomite and siliceous rock,uranium and tho⁃rium are mainly adsorbed or stored in small heavy minerals,and the helium produced is released in the form of decay recoil,which has the characteristics of continuous release.While uranium and thorium in basement granite gneiss,bauxite and sandstone are mainly stored in large heavy minerals.When the formation temperature does not exceed the sealing temperature,helium is accumulated in heavy minerals.When the abnormal high tempera⁃ture breaks through the sealing temperature of helium in heavy minerals,the accumulated helium is released cen⁃trally,which has the characteristics of“episodic release”.Combined with the scale and U and Th content of heli⁃um source rocks,it is considered that the basement granite gneiss,mudstone,bauxite and sandstone are the main helium source rocks in this area,and dolomite,siliceous rock and coal are the secondary helium source rocks.In the early Cretaceous,natural gas was accumulated on a large scale.At this time,helium gas was re⁃leased under the action of abnormal high temperature,which was sepa

关 键 词：氦气 铀钍赋存状态 重矿物 氦气释放方式 花岗片麻岩 铝土岩 

分 类 号：TE132.3[石油与天然气工程—油气勘探]