Numerical study on mobilization of oil slugs in capillary model with level set approach

Abstract

Numerical investigation on mobilizing oil slugs trapped in an axisymmetric capillary tube saturated with water was conducted. The governing equations for the incompressible two-phase core-annular flow in a capillary model were derived. Numerical solutions for capturing the evolution of interface between oil and water were developed using a level set approach. A projection method was applied to obtain the velocity field of the twophase flow. The existence of a water film between the oil slug and solid tube wall was evident in mobilizing the oil slug, and the water film clearly reduced the external pressure required to mobilize the oil slug. This result matches with the experimental phenomena reported in the literature. New phenomena in oil slug mobilization and motion were also found in the numerical investigations. The results obtained showed the high efficiency of the presented approach and the significance of water film in improving the mobilization of oil slugs.