应用核磁共振进行聚驱后泡沫驱油特性研究

采用并联岩心进行聚驱后泡沫驱油实验,利用核磁共振技术,对驱替后岩心的不同直径孔隙内的流体分布进行了研究,得到了水驱、聚合物驱、泡沫驱替阶段的驱出油的孔径范围以及剩余油分布.实验结果表明,与水驱和聚合物驱相比,泡沫驱增大了波及的孔径的范围.泡沫可以在水驱和聚驱易发生窜流的大孔径通道形成封堵,从而波及到了水驱和聚驱未波及到的孔径,不但大幅度的提高了低渗岩心的采收率,也驱出了部分高渗岩心的小孔径的油.

Foam Flooding after Polymer Flooding:Displacement Characteristics Studied by NMR Spectroscopy

The displacement process during foam flooding after polymer flooding was studied experimentally with parallel cores with different permeability contrast. The fluid distribution in cores was measured by NMR spectroscopy after water flooding, polymer flooding and foam flooding under different processes and various heterogeneity conditions. The distribution area of the bores from which oil was swept out was calculated. The results showed that foam flooding can sweep bores with a wider range of aperture, and bores in which water channeling and/or polymer-channeling may occur. Foam can swept oil out from the bores that cannot be reached by water and polymer flooding. In conclusion, foam flooding can not only improve the oil recovery from low permeability cores but also sweep the oil out from microbores in the cores with high permeability.