塔里木盆地深部油气藏类型与分布特征

摘要

Petroleum exploration of the Tafim Basin has started to move towards deep reservoirs inevitably along with the deepening of exploration in shallow reservoirs.Based on the latest exploration results,we report the research and exploration advances in this field in this study.The classification and distribution of deep reservoirs in the basin were analyzed based on the geological features and accumulation mechanisms of different types of deep reservoirs in the basin.Results show that the continued increasing of deep drills and hydrocarbon reservoirs is indicative of a prospective hydrocarbon exploration potential.According to the physical properties and evolution of reservoir,the deep reservoirs can be classified into conventional reservoirs,tight reservoirs and reformation reservoirs.Based on the trap types,the conventional reservoirs can be further classified into anticlinal reservoirs,block reservoirs and lithostratigraphic reservoirs.Based on the relationship between hydrocarbon charging time and evolution history of reservoir,the tight reservoirs can be further classified into primary tight reservoirs and secondary tight reservoirs.Based on the forming mechanisms of reservoir,the reformation reservoirs can be further classified into fluid reformation reservoirs,structural reformation reservoirs and comprehensive reformation reservoirs.The distribution of deep reservoirs in the Tarim Basin is complex.Tectonic patterns and evolution control the spatial distribution of reservior,while sedimentary environment and diagenetic evolution control vertical distribution of reservoir.The present deep petroleum exploration in the basin should focus on the ideas as follows:(1) reservoir rocks control hydrocarbon distribution,which suggests a strategy of exploration in multiple layers;(2)focus on tight and reformation reservoirs,as well as conventional reservoirs;and(3)exploration could be expanded to the slope and depression areas which are close to source rocks.%随着塔里木盆地中浅层油气勘探不断深入,深部油气勘探成为研究区必然选择.以塔里木盆地深部最新油气勘探开发资料为依据,揭示了盆地深部油气勘探现状,进一步结合前人研究成果剖析了盆地深部不同类型油气藏地质特征及成因机制,划分了深部油气藏类型并阐明分布特征.结果表明,塔里木盆地深部钻井数比例逐年增大,油气三级储量逐年递增,深部油气勘探潜力巨大;根据油气藏储层特征、物性演化机制及源储接触关系,塔里木盆地深部油气藏可划分为常规油气藏、致密油气藏及改造型油气藏3种8类,常规油气藏包括背斜、断块及岩性-地层类油气藏,致密油气藏包括先成型、后成型致密油气藏,改造型油气藏包括流体改造型、构造改造型及综合改造型油气藏;塔里木盆地深部油气藏分布规律复杂,构造格局与演化控制了其平面分区分带富集,沉积成岩背景与演化控制了其纵向分层分段富集;综合研究表明,当今塔里木盆地深部油气勘探应注重储层控油气作用,立足多目的层共同勘探,以致密油气为主导,改造型油气藏为重点,兼顾常规油气,逐步向盆地斜坡、坳陷处紧邻源岩的部位拓展.