【摘要】 从微观孔隙结构出发,将微观孔隙网络模型和宏观数值模拟模型有机结合,求取低速非线性渗流启动压力梯度。在多层长岩心水驱油实验基础上,对实验结果分别进行考虑启动压力梯度和不考虑启动压力梯度的拟合,结果显示考虑启动压力梯度的拟合结果更好。选择考虑启动压力梯度的数值模型给出的网格压力、饱和度数据进行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,且高渗层变化均不明显;不同工作制度下低渗层压力变化很大,提高驱替速度时低渗层的压力会在高渗层开时下降,而关闭高渗层会大幅增加低渗层的压力。更多还原

【Abstract】 Multi-layer long core experiment of waterflooding is done mainly for resolving the problems of inter-layer contradiction,low waterflooding efficiency and low-permeability reservoir produced hardly in vertically heterogeneous reservoir.Threshold pressure gradient is a common phenomenon in low permeability reservoir.This paper calculates the threshold pressure gradient by integrating pore-scale network model and macroscopic numerical simulation.Laboratory findings which matched by considering the threshold pressure gradient and not considering the threshold pressure gradient,respectively,after finishing the experiment.The result is that the former is much closer to the production performance of real reservoir.Using the grid pressure and saturation data which selected from the better matching result model to study flow field,the findings indicate that pressure increased,oil saturation decreased with enhance injection rate in high,middle and low permeability reservoir,but high-permeability reservoir changed indistinctly.Low-permeability reservoir pressure changed greatly under different work routines.Enhance injection rate,it will be decreased when open the high-permeability reservoir,contrarily,and it will be increased when shut in the high-permeability reservoir.更多还原