多层长岩心水驱油实验数值模拟研究

Numerical simulation study on multi-layer water displacing oil test with long core

多层长岩心水驱油实验,主要用于解决纵向非均质油藏普遍存在的层间矛盾突出、水驱效率低、低渗储层难以动用等问题而开展的。文中在完成了多层长岩心水驱油实验的基础上对实验结果分别进行了考虑启动压力梯度和不考虑启动压力梯度的拟合,结果表明,考虑启动压力梯度的拟合结果更好。选择其中拟合效果较好的模型给出的网格压力、饱和度数据进行了水驱油渗流场变化研究,研究结果表明:高中低渗层的压力、含油饱和度分布随注入速度的提高分别有所提高和降低,且同时表现出高渗层变化不明显;不同工作制度下低渗层压力变化很大,即提高驱替速度时低渗层的压力在高渗层开时会下降,反之提高驱替速度关闭高渗层会大幅增加低渗层的压力。

Multi-layer water displacing oil test with long core is done mainly for resolving the problems of inter-layer contradiction,low waterflooding efficiency and low-permeability reservoir existed in vertically heterogeneous reservoir.This paper simulates the matching laboratory findings by considering the threshold pressure gradient after finishing the experiment.The result shows that the matching result of considering the threshold pressure gradient is the better one and is much close to the production performance of real reservoir.Using the grid pressure and saturation data which are selected from the better matching result model to study flow field,the findings indicate that pressure increased,oil saturation decreased with enhancing injection rate in high,middle and low permeability reservoir,but high-permeability reservoir changes indistinctly,low-permeability reservoir pressure changes greatly under different work routines and enhance injection rate.It will be decreased when opening the high-permeability reservoir.Conversely,it will be increased when shutting in the high-permeability reservoir.The conclusion is very important for resolving problems during water injection stage in vertically heterogeneous reservoir.