台西盆地地层沉积特征与成烃-成藏地质条件

台西盆地是主体跨台湾岛与福建陆域之间的台湾海峡地区的中、新生代叠合盆地,在盆地东部及台湾岛已有相当的油气发现。在前人研究基础上,通过地震资料精细解释及海陆对比分析,开展了盆地地层分布、沉积特征及油气成烃成藏潜力研究。结果表明:盆地中-新生代地层发育,经历了白垩纪—始新世裂陷湖相、渐新世抬升剥蚀及中新世至今沉积、沉降3个阶段;发育下白垩统、古新统及始新统烃源岩,主要发育湖相、三角洲、水下扇和河道砂体等多种类型储集体;具有形成中型油气田的物质基础与较好的油气资源勘探发现潜力。

Sedimentary features and geological conditions for hydrocarbon generation and accumulation in Taixi Basin

The Taixi Basin is a superimposed Mesozoic-Cenozoic basin located in the Taiwan Strait,with its main body lying between Taiwan Island and onshore Fujian.Large volume of hydrocarbon has been discovered in the eastern basin and Taiwan Island.Based on the previous studies,the study focused on stratigraphic distribution,sedimentary features and hydrocarbon generation potentials of the basin through fine interpretation of seismic data and marine-continental comparative analysis.The results show that evolution of the Mesozoic-Cenozoic basin could be subdivided into three stages,namely the Cretaceous-Eocene rift depression lacustrine stage,the Oligocene uplift denudation stageand the Miocene-present sedimentation and subsidence stage.Correspondingly,three sets of source rocks are developed in this basin including the Lower Cretaceous,Paleocene and Eocene source rocks.The reservoir types are mainly clastic rocks,such as lacustrine facies,delta,subaqueous fan and channel sands.Medium-sized oil-gas fields may develop in the study area due to its favorable geological conditions for hydrocarbon generation and accumulation,thus its hydrocarbon exploration potential is believed to be relatively high.