Colloidally-induced fines release in porous media

Abstract

A critical value of the total ionic strength (CTIS) has been found to exist for mixed salt solutions flowing in porous media. If the ionic strength drops below this value, significant amounts of fines are released in-situ due to colloidal forces, causing drastic formation damage. For a NaCl/CaCl2 system, the CTIS is strongly dependent on the relative amount of CaCl2 present in the solution. The concept of a critical salt concentration (CSC) and the analysis based on DLVO theory has been extended to mixed salt systems to estimate the CTIS. The difference between critical flocculation concentration (CFC), and the present definition of CTIS has been pointed out. Predictions of this analysis are consistent with experimental observations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28497/1/0000294.pd