石油实验地质2025，Vol.47Issue(4)：781-790,10.DOI:10.11781/sysydz2025040781
鄂尔多斯盆地大牛地气田氦气成藏特征及其贫化主控因素
Helium accumulation characteristics and main controlling factors of helium depletion in Daniudi Gas Field,Ordos Basin
摘要
Abstract
A certain amount of helium is found in the natural gas of both the Dongsheng and Daniudi gas fields in the Hangjinqi area of the Ordos Basin.However,the average helium content in the Daniudi Gas Field is only about one-fourth of that in the Dongsheng Gas Field.Given the similar basement geology and tectonic background of the basin,it is necessary to investigate the factors leading to this significant difference.A systematic analysis of the geochemical characteristics of associated helium in natural gas and the key factors controlling helium accumu-lation was conducted.The results revealed that the helium content in the Paleozoic natural gas of the Daniudi Gas Field ranged from 0.000 1%to 0.15%,classifying it as a low-to medium-helium gas field.Helium content in the Upper Paleozoic was relatively higher,and vertically,it gradually increased from the lower to the upper layers,showing relative enrichment in shallower layers.The helium in the Paleozoic source rocks of the Daniudi Gas Field was typical crust-source helium,mainly derived from the Archean-middle Paleoproterozoic metamorphic rock-granite series in the basin basement.The contribution of helium generated by potential helium source rocks in the Upper Paleozoic was minimal.By comparing the geological conditions and accumulation characteristics of the Upper Paleozoic between the Daniudi and Dongsheng gas fields,it was found that the basement helium source rocks in both gas fields were similar in rock type,mineral composition,thickness,and uranium(U)and thorium(Th)contents,suggesting that the differences in source rock were not responsible for the significant difference in helium content.In the Daniudi area,only one second-level deep fault was developed in the basement of the Daniudi area,and its activity during the Yanshanian-Himalayan period was relatively weak,resulting in limited activity of secondary faults.This led to a lack of effective channels for helium to migrate upward from the basement helium source rocks,as well as vertical transport and lateral adjustment.Due to the mismatch in spatiotemporal configu-ration of key accumulation factors for helium and conventional gas,helium entered the Paleozoic gas reservoirs in Daniudi only by diffusion,resulting in low helium content.Therefore,the main factors contributing to helium depletion in the Daniudi Gas Field are the underdevelopment and weak activity of deep faults and secondary faults in the basement,the mismatch between helium and conventional gas accumulation conditions,the lack of an effective transport system,and the reliance on concentration-driven diffusion for helium migration.关键词
断裂发育/氦气成藏要素/贫化主控因素/氦源岩/大牛地气田/鄂尔多斯盆地Key words
fault development/helium accumulation factors/main controlling factors of depletion/helium source rock/Daniudi Gas Field/Ordos Basin分类
能源科技引用本文复制引用
王杰,安川,马亮帮,姜海健,张威,陶成,王付斌,董勍伟..鄂尔多斯盆地大牛地气田氦气成藏特征及其贫化主控因素[J].石油实验地质,2025,47(4):781-790,10.基金项目
中国石油化工股份有限公司科技部重大项目(P23230,P23244)联合资助. （P23230,P23244）
