摘要
准噶尔盆地西北缘二叠-三叠系储层是洪积扇相砂砾岩体,油藏由于长期注水开发,后期形成了许多高渗流通道。从静态成因、工程动态成因角度总结了高渗流通道的形成原因,认为砾岩储层中高渗通道的主要成因有:沉积微相控制、微裂缝网络连通、沉积成岩作用程度弱(欠压实砂砾体弱胶结)、特殊的支撑砾岩岩石沉积结构、储层改造、长期注水微颗粒迁移、不同岩性沉积界面高渗通道、不整合面等8种。通过确定高渗透段的成因及其识别特征,将其嵌到单期水道内,建立高渗透层段的空间分布规律。高渗通道的开发动态特征为:高渗通道对应段吸水量高、高渗通道对应段吸水量随注水时间的延长而一般吸水量明显增大、高渗通道对应段地层压力从不明显到逐渐增高。由于储层高渗流通道的存在,导致注入水无法起到有效驱油作用,注入水无效循环严重影响了油藏注水开发效果。总结高渗流通道的特征并有效识别,是改善砾岩油藏储层开发效果的地质基础。
The reservoir of Triassic-Permian strata in the northwest zone of Zhungar basin is a pluvial fan and sand-conglomerate reservoir, and the genesis causes of its high-permeability pathways are discussed in this paper. From the genesis and identifications of pluvial fan glutenite high-permeability pathways, 8 types of highpermeability pathways are found in the glutenite reservoir. In the middle and later stages of development, there are static and dynamic factors for injection-production controlling high-permeability pathways, which are sedimentary micro facies, micro fracture network, diagenesis uncompaction, support glutenite structure, and which induce hydraulic fracture, grain motion, depositional interface, unconformable interface etc., developing characteristics of highpermeability pathways with water intake capacity more than adjacent beds, and injection-production formation pressure enhanced apparently. Because of high-permeability pathway generation, injection-water can not drive oil effectively, which is the reason of bad productivity. This paper provides a geological basis to understand the characteristics of high-permeability pathways and to identify them.
出处
《科技导报》
CAS
CSCD
北大核心
2009年第23期19-27,共9页
Science & Technology Review
关键词
砾岩油藏储层
油藏注水开发
高渗通道
conglomerate reservoir
injection-water drive oil
high permeability channels
