韵律层内剩余油分布的数值模拟研究

韵律层内的剩余油已成为油田开发后期调整挖潜的主要目标,根据精细数值模拟研究结果认识层内剩余油的分布规律,可以指导高含水油田后期的开发调整。以胜坨油田胜二区8砂组的地质条件为基础建立概念模型,采用油藏数值模拟方法,分析了同一个韵律层内剩余油的分布规律。研究结果表明:水驱计算至高含水期后,在同一个韵律层内,垂向上上部小层剩余油饱和度高,下部小层剩余油饱和度低,接近于残余油饱和度;小层厚度越小,油、水的地下密度差越大,原油黏度越小,这种现象越明显;而注水井射孔位置对韵律层内垂向上剩余油的分布基本没有影响。因此,对已进入高含水开发阶段的胜坨油田,后期调整挖潜的目标是韵律层内的上部层段。 

Numerical Simulation of Remaining Oil Distribution in Cyclothem

The remaining oil distribution in cyclothem is playing more and more important role in the later period of oilfield development,so it is very important to study the remaining oil distribution in cyclothem for the later development adjustment of the high water-cut reservoirs using the fine numerical reservoir simulation.Conceptual models have been built on the basis of geological condition of 8th sand set of Sheng II Block in Shengtuo Oilfield to analyze the distribution rule of remaining oil in the same cyclothem.The results show that,when water flooding is calculated till the high water-cut period,vertically,remaining oil saturation of upper layers is high and that of lower layers is low and close to irreducible oil saturation in the same cyclothem.Furthermore,the smaller the layer thickness,the bigger the density difference between oil and water,and the smaller the oil viscosity,the more obvious this trend will be.But the location of perforation in injection wells has little effect on the remaining oil distribution.So the upper layers in cyclothem should be the target for later development adjustment in high water-cut period of Shengtuo Oilfield.