河控三角洲水下分流河道砂体内部建筑结构模式

An internal structure model of subaqueous distributary channel sands of the fluvial-dominated delta

单砂体内部夹层及其建筑结构对注入剂驱油以及剩余油的形成作用越来越大。在河控三角洲水下分流河道沉积模式的指导下,利用露头照片和连井剖面资料,建立了河控三角洲水下分流河道砂体的内部结构模式,确定了单一水下分流河道内部夹层的三维展布形态。研究发现,水下分流河道内部存在侧积夹层、前积夹层和垂积夹层3种类型。客观地反映了水下分流河道内部基本单元的三维展布形态,真实再现了水下分流河道砂体的内部建筑结构。

Thin intercalations and internal structures within mono-sandbody play a more and more important role in injection flooding and remaining oil generation.Based on depositional models of subaqueous distributary channels in the fluvial-dominated delta,we established an internal structure model for subaqueous distributary channels in the fluvial-dominated delta and figured out a three-dimensional distribution mode of intercalations in a single subaqueous distributary channel using data of outcrop photos and well sections.The results show that there are three kinds of intercalations within subaqueous distributary channels.The first is a lateral accretion intercalation that is formed when channels shift laterally,the second is a foreset intercalation that is formed when channel progradation occurs in a front slope,and the third is a vertical accretion intercalation that is formed when channel accretion occurs vertically in a flat area.These different intercalations may objectively reveal a three-dimensional distribution mode of basic units within subaqueous distributary channels and veritably reflect internal structures of subaqueous distributary channel sands in the fluvial-dominated delta.