基于流线数值模拟研究高含水后期油田的剩余油分布

剩余油分布研究是高含水期油田的难点问题。以济阳拗陷孤东七区西馆陶组Ng6~(3+4)层高含水开发实验区块为例,在地质分析的基础上,建立起小网格精细三维地质模型及参数模型;通过试验区储量、压力、含水率和单井含水拟合,85%的单井历史拟合误差5%。采用流线数值模拟技术显示出高含水后期密井网条件下流体推进特征及剩余油分布模式,得出:(1)流线显示目前地下储层形成大孔道高渗带,流体基本沿高渗带运移,驱油效率明显降低。(2)目标油层组剩余油分布明显受到沉积相、沉积韵律、层内非均质、生产井网等因素的控制;剩余油平面上主要分布在微构造高点、层内低渗透区及注采不完善区,纵向上主要集中分布在主力厚油层的顶部。

Application of streamline numerical simulation method to study of remaining oil distribution in high water-cut stage oilfield

According to the geologic and developmental features of the Ng6 3+4 of Neogene Guantao Formation in western No.7 district in Gudong Oilfield,one experimental zone in Ng63+4 unit is used to study the distribution of remaining oil in high water cut stage oilfield.The history matching of the reserves,pressure,moisture content and single drilling well water cut in the experimental zone produces a fine 3D geological model and parameters mode of less than 5% errors for 85% single-drilling wells. With the help of streamline numerical simulation technique, it obtains the characteristics of fluid migration under the condition of dense well pattern in high water-cut stage and divides remaining oil distribution patterns.It shows that large channel and high permeability zone are formed in the underground reservoir and the fluid migrates mostly along the high permeability zone. At the same time,oil displacement efficiency decreases obviously.The remaining oil distribution is controlled by sedimentary facies,sedimentary rhythm intraformational heterogeneity and drilling well network,the remaining oil occurs in the top of micro-structures,low permeable section in the plane and mainly concentrates on the top of the positive rhythm in the thick oil layer.