摘要
基于三塘湖盆地油气资源勘探程度最低、资源前景最不明朗的下石炭统,开展了新层系的石油地质条件与勘探潜力分析评价工作。采用野外露头、地球化学分析及储层薄片观察等研究手段,揭示了目的层纵向沉积环境演化、烃源岩及储层等成藏地质特征。研究表明:三塘湖盆地早石炭世为残留海弧后盆地,具有浅海相沉积特征,下石炭统纵向沉积环境经历了岛弧火山活动和陆源碎屑充填、古洋封闭半深水—深水环境、挤压抬升陆源碎屑充填浅水环境和造山抬升盆地萎缩4个演化阶段。其中,封闭半深水环境和浅水沉积环境中烃源岩广泛分布,有机质类型达到中等烃源岩标准,岩石薄片中存在大量沥青,证实下石炭统烃源岩不仅具备生烃能力,而且也发生过大量排烃过程。下石炭统发育火成岩与碎屑岩两大类储层,尽管储层整体致密,但裂缝与溶孔发育,改善了储集油气条件,尤其是花岗岩裂缝的发育对溶蚀孔隙具有明显的连通作用。综合分析,围绕下石炭统烃源岩可发育自生自储和下生上储两类油气藏。自生自储油气藏发育在远离油源断裂的构造稳定区,具有原生藏的特点;下生上储油气藏发育在石炭系内部油源断裂附近,与断层岩性油气藏有关。
This paper aims to conduct the first analysis and evaluation of the oil and gas geological conditions and exploration potential of the Lower Carboniferous strata in the Santanghu basin,which has the lowest level of exploration and the most uncertain resource prospects.Based on field outcrop observations,geochemical analysis,and reservoir thin section observations,the vertical sedimentary environment evolution,hydrocarbon source rocks,and reservoir geological characteristics of the target layer are revealed.The study indicates that the Santanghu basin in the Early Carboniferous was a residual back-arc basin with shallow marine sedimentary characteristics.The vertical sedimentary environment of the Lower Carboniferous strata experienced four stages of evolution:Island arc volcanic activity,closure of ancient oceans leading to semi-deep water environments,compression and uplift of continental-derived clastic sediment filling shallow water environments,and orogenic uplift basin contraction.Among them,hydrocarbon source rocks are widely distributed in the semi-deep water environment and shallow water sedimentary environment,and the organic matter type meets the standard of moderate hydrocarbon source rocks.The presence of abundant asphalt in rock thin sections also confirms that the hydrocarbon source rocks of the Lower Carboniferous not only have hydrocarbon generation ability but also have undergone a large amount of hydrocarbon expulsion processes.The Lower Carboniferous strata developed two major types of reservoirs:Igneous rocks and clastic rocks.Although the reservoirs are generally tight,the development of fractures and dissolution pores has improved the conditions for oil and gas accumulation,especially the development of granite fractures,which has a significant connectivity effect on dissolution pores.Comprehensive analysis suggests that around the hydrocarbon source rocks of the Lower Carboniferous,two types of oil and gas reservoirs can be developed:Self-generated and self-stored,and lower-generated and upper-stored.Among them,self-generated and self-stored oil and gas reservoirs are developed in structurally stable areas far from the oil source faults and have the characteristics of primary reserves.Lower-generated and upper-stored oil and gas reservoirs are developed near oil source faults within the Carboniferous system and are related to fault lithology oil and gas reservoirs.
作者
王伟明
胡美硕
焦立新
杨斌
苗长盛
孙宏亮
周志超
曲希玉
Wang Weiming;Hu Meishuo;Jiao Lixin;Yang Bin;Miao Changsheng;Sun Hongliang;Zhou Zhichao;Qu Xiyu(National Key Laboratory of Deep Oil and Gas(China University of Petroleum(East China)),Qingdao 266580,Shandong,China;School of Geosciences,China University of Petroleum(East China),Qingdao 266580,Shandong,China;The Institute of Exploration and Development of Tuha Oilfield,PetroChina,Hami 839009,Xinjiang,China;Petroleum Exploration Division,Tuha Oilfield Company,Hami 839000,Xinjiang,China;College of Surveying and Mapping Engineering,Changchun Institute of Technology,Changchun 130012,China)
出处
《吉林大学学报(地球科学版)》
北大核心
2025年第5期1401-1419,共19页
Journal of Jilin University:Earth Science Edition
基金
国家自然科学基金项目(42272145,41672125)
山东省自然科学基金项目(ZR2020MD027)
吉林省自然科学基金项目(20220101183JC)
第二批天山英才培养计划青年托举人才项目(2023TSYCQNTJ0041)。
关键词
三塘湖盆地
下石炭统
油气
储层
石油地质条件
成藏模式
勘探潜力
Santanghu basin
Lower Carboniferous
oil and gas
reservoir
petroleum geologic conditions
reservoir forming model
exploration potential
