贝尔凹陷贝301区块南二段单砂体级沉积特征

SEDIMENTARY CHARACTERISTICS OF THE INDIVIDUAL SANDBODIES IN NO. 2 MEMBER OF NANTUN FORMATION OF BEI-301 BLOCK IN BEIER SAG

基于高分辨率层序地层学和现代沉积学理论构建了研究区单砂体级高分辨率层序地层格架，编制36张单砂体级沉积微相图，建立了目的层扇三角洲沉积体系中8种沉积微相定量识别标准。研究认为：水下分流河道和河口坝是最主要的微相；水下分流河道二元结构不明显，其宽度与小层相比明显变窄、弯曲程度普遍较小；河口坝是河口坝、决口扇、事件沉积体等的复合体。该研究建立的研究区目的层沉积模式确定了单砂体的平面、纵向展布关系，为贝301区块综合挖潜提供了重要地质依据，对其他区块的精细油藏描述具有参考价值。

Based on high-resolution sequence stratigraphy and modem sedimentology theory, the high-resolution sequence stratigraphic framework of the individual sandbodies in the study area is established, 36 sedimentary mi- cro-facies graphs of the sandbodies are compiled for this kind of sandbody, 8 kinds of quantitative identifing stand- ards of sedimentary micro-facieses of fan-delta sedimentary system for the target layers are established. The studies show that underwater distributary channels and mouth bars are the most primary miero-facieses; the binary structure of the underwater distributary channels is not obvious, comparing with the single layer, the width of these channels obviously becomes narrow, and moreover the bent degree is generally reduced; the mouth bars are the complexes between the bars and crevasse splay and sedimentary bodies of the events. The established sedimentary models of the target bed in the study area determine the relations of the horizontal and vertical spreads for the individual sand- bodies, provide the important geological evidences for the comprehensive potential-tapping of Bei 301 Block, and moreover possess the reference value for the fine reservoir characterization of the other blocks.