滨南油田沙三段浊积砂体沉积特征与有利储集相带分析

Sedimentary Characteristics and Favorable Reservoir Facies of E2s3 Formation in Binnan Oilfield

滨南油田沙三段沉积时期为湖盆断陷期,由于强烈的构造活动与充足的物源,发育近岸浊积岩、远岸浊积扇以及远岸滑塌透镜体三种类型的浊积砂体。本文在岩心观察的基础上,结合薄片鉴定、粒度分析等技术方法,对目标层位的沉积特征进行了分析。结果表明,研究区浊积砂体储层发育砾岩、砂岩、深湖泥岩等多种类型的岩性;粒度概率累积曲线与C-M图都显示出典型的浊积岩特征;沉积构造以递变层理、平行层理以及水平层理等为主,常见典型Bouma序列。通过对典型井的单井相分析,建立了三种浊积体储层的沉积模式。最后在分析了各类储层储集条件的基础上,指出本区浊积体储层物性差异很大,为中孔中渗到低孔低渗,并且远岸浊积扇的辫状水道微相砂岩最有油气富集潜力。

The third member of Shahejie formation（E2s3） of Binnan Oilfield developed in basin＇s rift epoch, because of the adequate sediments and intense tectonic activities, turbidite reservoirs such as proximal turbidites,distal turbidites and lenticular turbidites were well developed. In this paper, based on the core observation, combined with thin section and grain size analysis and other methods, sedimentary characteristics of the main objective formation were studied. The results show that, turbidite reservoirs are mainly composed of conglomerate rock, sandstone, mudstone and dolostone; both grain size probability curves and C-M diagram display characteristics of turbidite sand; graded bedding, parallel bedding and horizontal bedding are predominant in this area, and classic Bouma sequence is common. At last, based on the analysis of different kinds of turbidite reservoirs, it＇s pointed out that reservoir physical property difference of target formation is big, both porosity and permeability are moderate to inferior. The braided stream microfacies of distal turbidites has a good potential of oil and gas accumulation.