非均质底水油藏堵水体系运移特征与封堵性能

In order to promote the widespread implementation of chemical water plugging technology in offshore fields, a three-dimensional (3D) heterogeneous physical simulation experiment with multiple measurement points was used to investigate the migration characteristics and water plugging effectiveness of the water plugging system during the bottom water energy development process in heterogeneous oil reservoirs. The results show that the water plugging system can selectively enter the medium and high permeability areas, causing a dense distribution of pressure equipotential lines and an increased displacement pressure difference, thereby achieving channel blocking. Furthermore, the degree of heterogeneity correlates positively with the enhancement of displacement pressure difference and model recovery percentage following the injection of the water plugging system and secondary water flooding. When the secondary water flooding reaches 95% water cut under high permeability contrast, the displacement pressure of the gel system increases by 0.4 MPa compared with low permeability contrast, and the particle system increases by 0.7 MPa; The produced degree of the gel system increases by 2.8%, and that of particle system increases by 3.4%. It is concluded that both gel and particle systems have good selective injectivity, which can migrate to medium and high permeability areas, block breakthrough channels, and convert bottom water into low permeability areas, thereby expanding the swept area and enhancing oil recovery.