四川盆地须家河组第四段湖泊三角洲沉积差异

摘要

根据野外露头、岩心观察和测井资料等宏观分析，结合铸体薄片图像分析和物性分析等微观测试分析手段，对四川盆地须家河组第四段湖泊三角洲沉积特征、岩石学特征、储层物性特征进行详细分析，结果表明研究区共发育长轴和短轴两种类型三角洲。长轴三角洲分布于川东南地区，短轴三角洲分布于四川盆地的川西陡坡带一侧，两种三角洲类型的岩性和储集特征差异较大。其共同控制因素有湖盆地形、构造活动、物源条件以及湖平面变化，其中构造活动是控制该区长、短轴三角洲沉积体系发育的主要因素。%Based on field outcrops,core observation and logging data with casting body slice image analysis and physical analysis,this paper makes a comparative study of the sedimentary characters, petrology characters and reservoir physical characters of Member 4 in Upper Triassic Xujiahe Formation of Sichuan Basin.The result shows that there are two types of deltas developing in study area.The long-axis delta mainly develops in the southeast sag of Sichuan,while the short-axis delta mainly develops in the west sag.These two types of deltas have great differences in lithology and reservoir characters.The topography of lake basin,tectonic action,provenance and changing of lacus level are the controlling factors, in which the tectonic action plays an important role in the sedimentary system development of the long-axis delta and the short-axis delta.