通南巴地区上三叠统须家河组沉积体系及其主控因素

近年来的勘探实践表明，通南巴地区上三叠统须家河组具有良好的油气勘探前景。通过野外剖面及岩心观察，结合测井和各种分析鉴定资料以及沉积相标志的综合分析，识别出冲积扇、河流、湖泊三角洲、湖泊（受间歇性海水改造）和海相三角洲5种沉积体系，建立了海陆过渡三角洲、冲积扇-辫状河三角洲-湖泊两种沉积演化模式。研究结果还显示，本区沉积体系主要受控于古气候、构造运动和物源区母岩性质：古气候控制着须家河组煤系地层特殊的砂、泥间互的沉积结构及生储盖组合；构造运动控制着各沉积时期的沉积体系类型及砂体展布；不同物源区母岩性质影响沉积物的组分与结构。

Sedimentary system and main controlling factors of the Upper Triassic Xujiahe Formation in Tongnanba area

Exploration and research show that the Upper Triassic Xujiahe Formation has good prospect for exploration in Tongnanba area. Based on observation of outcrops and core, combining with comprehensive analysis of well logging and analysis data, as well as facies marks, the paper concludes that Xujiahe Formation has a composite sedimentary system consisting of alluvial fans, fluvial, lacustrine deltas, lacustrine (affected by seawater), marine deltas facies. The main sedimentary system models are marine-continental transition delta and alluvial fans-braided river delta-lacustrine. It is also revealed that the paleoclimate, tectonic movement and provenance had controlled the sedimentary system. The paleoclimate controlled the especial sedimentary structure formed by alternating layers of mudstone-sandstone and source-reservoir-cap assemblage of Xujiahe Formation. Tectonic movement controlled sedimentary system types and sand-body distribution during every sedimentary period. The property of parent rock in different provenances have controlled the composition and the texture of sediments.