Formation Damage due to Colloidally Induced Fines Migration

The in-situ release of fine particles in a porous medium resulting from changes in the colloidal character of fines induced by changes in the electrolytic condition of the permeating fluid and its effects on processes related to enhanced oil recovery (EOR) are examined. Experimental results show that high pH and low salinity cause fines to be released which, in turn, causes a drastic decline in the permeability of the medium. These results and other key experiments establish the interplay between salinity changes, cation exchange, and pH during a water shock, and elucidate the vital role of the ion-exchange process in formation damage. A physico-chemical model based on the fundamental principles of ion exchange and colloidal chemistry shows qualitative agreement with experimental observations. The results of this study will find use in various areas such as: bacteria migration in soils, failure of earthen embankments, and contaminant transport during ground water flow.