不同类型储层驱替速度对提高原油采收率的影响

从渗流力学的基本规律出发,对几种不同类型储层驱替速度对提高油气采收率的影响进行了理论探讨.研究结果表明,对于一维均质储层,加大水湿层内垂向非均质储层和存在启动压力梯度的低渗透储层的驱替速度,能提高油气采收率;对于水湿双重介质储层,如果基质渗透率很低,应适当降低驱替速度,可以更充分地发挥基质与裂缝系统间毛管力窜流的交换作用,有利于提高油气采收率.对于水湿层内垂向非均质储层和基质渗透率较大的双重介质储层,要平衡毛管力的有利和不利两个方面的作用,驱替速度过大或过低都会影响采收率的提高,因而存在一个最佳驱替速度.

Effects of displacement rate on enhance oil recovery efficiency in different types of reservoirs

On the basis of seepage flow mechanics,the impact of displacement rate on enhance oil recovery efficiency in different types of reservoir was investigated.The research results indicate that the increase of displacement rate of water-wetting layers in vertically heterogeneous and low-permeability reservoirs with kickoff pressure gradient is favorable for improving the oil recovery efficiency for one-dimensional homogeneous reservoir.As to water-wetting dual medium reservoirs,if the matrix permeability is very low,the proper reduction of displacement rate will sufficiently exert the exchange action between matrix and fracture caused by the difference of capillary pressures and enhance oil recovery.As to water-wetting vertically heterogeneous reservoirs and dual medium reservoirs with high-permeability matrix,the advantageous and disadvantageous actions of capillary pressure should be balanced.If the displacement rate is too hight or too low,the improvement of recovery efficiency will be influenced.So,an optimal displacement rate should be found out.