水驱不同注采位置油藏特征——以萨尔图油田北二西区块油藏为例

摘要

利用油藏剩余油粘度和岩心分析方法,对萨尔图油田北二西区块油藏剩余油粘度、驱油效率等参数进行了研究.结果表明,水驱主流线不同注采位置剩余油粘度、油藏流度、含油饱和度和驱油效率均呈现不同程度的非均质性,并受储层物性、注采位置和驱油时间等因素控制；主流线从注水井到采油井方向,油藏非均质性增强,含油饱和度增大,驱油效率减小,且驱油效率与渗透率成正相关,相关程度随渗透率的增大而增高,剩余油粘度与渗透率微弱相关,含油饱和度与渗透率低度相关；随水驱油时间的延长,剩余油粘度和驱油效率增大,油藏流度与含油饱和度下降.综合挖潜水驱不同注采位置剩余油仍有一定潜力,其中主流线靠近采油井位置开采潜力最大；聚合物驱油则更合适,可根据聚合物驱油藏流度比控制范围和剩余油粘度的测定结果,确定聚合物溶液的粘度及质量浓度.%Geochemical parameters (eg. remaining oil viscosity, oil displacement efficiency, etc. ) of North-II -West area in the Saertu oilfield are obtained through methods of remaining oil viscosity and core analysis. The experimental results show that oil viscosity, mobility, saturation and oil displacement efficiency, etc. of remaining oil are more or less heterogenetic at different injection-production locations in the direction of main stream line of water-flooding, and are controlled by reservoir physical property, injection -production location and time duration of water-flooding, etc. The heterogeneity of reservoir geochemical parameters show increasing trend from the injection wells to the production wells of main steam line, with the increase of oil saturation and decrease of oil displacement efficiency. There is a positive correlation between rock permeability and displacement efficiency and the correlation coefficient increases with increasing permeability. The remaining oil viscosity is weakly correlated with rock permeability that is poorly correlated with oil saturation. With the water-flooding, the remaining oil viscosity and oil displacement efficiency increases while reservoir mobility and oil saturation decreases. Using water-drive at different injection-production locations can exploit some extent of remaining oil potentiality, with the greatest exploitation potentiality being located in those where the mainstream line is close to the production well. However, the polymer flooding will be a better way to exploit remaining oil, and the polymer concentration and viscosity can be determined in function of remaining oil viscosity and the range of controlling mobility ratio of polymer flooding.