鄂尔多斯盆地姬塬地区长8油层组高分辨率层序分析

以高分辨率层序地层学原理为指导，利用钻井岩芯、测井和岩矿分析等资料，对鄂尔多斯盆地姬塬地区延长组长8油层组进行沉积相和基准面旋回划分，将其确定为浅水三角洲沉积体系，划分为2个中期（MSC1和MSC2）和6个短期（SSC1～SSC6）基准面旋回。研究表明:长82沉积期研究区主要为湖域扩大的三角洲前缘及前三角洲沉积环境;长81沉积期，研究区主要为三角洲平原沉积环境；分析了不同级别的基准面旋回叠加式样与沉积相展布、演化规律之间的关系，并与正常沉积的三角洲层序发育特征进行了对比。在此基础上，以短期旋回为单元，建立了高分辨率层序地层格架和编制了长81和长82的层序—岩相古地理图，得出相对正常的三角洲而言，浅水三角洲沉积体系具有A/S（可容纳空间/沉积物补给）较小、河口坝不发育、有利储层发育的微相为长距离延伸的分流河道砂体和分流河道砂体主要发育在短期上升半旋回的结论。

Analysis of High-Resolution Sequence Stratigraphy in Chang-8 Subsection of Yanchang Formation, Jiyuan Area of Ordos Basin

With the theory of high-resolution sequence stratigraphy,the base-level cycles in Chang-8 oil set of Yanchang Formation in Jiyuan area of Ordos Basin are recognized as 2 middle-term cyclic sequences(MSC1 and MSC2) and 6 short-term cyclic sequences(ssc1-ssc6) and the sedimentary environment is a shallow-water delta by utilizing the data of well logging,core and rock and mineral analysis.The results indicate that the delta front and predelta of expanded lake developed in Chang-82 and delta plain appeared in C...