Effects of Injected Water Chemistry on Waterflood Sweep Efficiency via Induced Fines Migration

摘要

Permeability decline during corefloods with varying water composition, especially with low salinity water, has been observed in numerous laboratory studies. It has often been explained by the lifting, migration and subsequent plugging of pores by fine particles, which have been observed in numerous core flood tests with altered water composition. In this work, the concept that this permeability decline may be used for mobility control during waterflooding was investigated. The Dietz model for waterflooding in a layer cake reservoir with a constant injection and production rate was combined with a particle detachment model to provide a simple analytical model for the process. The application of the model to an example data set showed induced fines migration may improve sweep efficiency for a given volume of injected water.