油水黏度比对油藏注水开发效果的影响

对于层间流体性质差异较大的多层非均质油藏,在进行笼统注水开发时,层间油水黏度比差异对于油藏开发效果有较大影响。通过使用CMG油藏数值模拟软件建立多层油藏一注两采机理模型,从剩余油分布、波及系数、驱油效率及采出程度等多个方面分析层间油水黏度比差异对开发效果的影响,确定多层合采油藏合理的层间油水黏度比级差界限。研究认为,多层非均质油藏笼统注水开发时,低油水黏度比油层对高油水黏度比油层有较大影响,层间油水黏度比级差越大,层间矛盾越突出,低油水黏度比层波及系数、驱油效率明显上升,高油水黏度比层波及系数、驱油效率大幅下降,层间动用程度差异越大,剩余油主要富集在高油水黏度比层,油藏开发效果越差,合理的层间油水黏度比级差应控制在3以下。

Influence of Oil-Water Viscosity Ratio on Reservoir Waterflooding Development Effect

For multi-layer heterogeneous reservoirs with large differences in fluid properties between layers, the difference in oil-water viscosity ratio between layers has a great influence on reservoir development effect during the development of general water injection. In this paper, the CMG software is used to establish a multi-layer reservoir mechanism model with one injecting and two producing wells, and the influence of oil-water viscosity ratio for development effect is analyzed from the aspects of remaining oil distribution, sweep efficiency, oil displacement efficiency and recovery degree. The effect is to determine the reasonable inter-layer oil-water viscosity ratio limits of the multi-layer reservoir. Results show that the development effect of different layer for multilayer reservoir is influenced by oil-water viscosity ratio, with the increase of oil-water viscosity ratio difference, the interlayer contradiction becomes larger, and the sweep efficiency and displacement efficiency increase obviously of the low oil-water viscosity ratio while sharp decrease in the high oil-water viscosity ratio layer, the remaining oil is mainly concentrated in the high oil-water viscosity ratio layer, and the reservoir development effect is worse. The reasonable interlayer oil-water viscosity ratio should be controlled below 3.