water salinity from 35 000 ppm to 0 ppm the upstream and downstream pressure helped quantify the damage if any fig1 and 2 provide examples of permeability and conductivity profiles during high salinity and fresh water displacement under experimental conditions utilizing two different core samples the process was then switched back to the high salinity brine to verify that the permeability of the sample had not been compromised after the pressure drop across the core stabilized and the high salinity brine permeability was reestablished the flow rate was abruptly i e shocked changed from the salt water solution to fresh water this step confirmed that the sample used was sensitive to water chemistry and the injection scheme the presence of clay particles in the effluent stream from the shocked cores was detected by the turbinity measurements the preferred embodiment of the present invention has been disclosed and illustrated however the invention is intended to be as broad as defined in the claims below those skilled in the art may be able to study the preferred embodiments and identify other ways to practice the invention that are not exactly as described in the present invention it is the intent of the inventors that variations and equivalents of the invention are within the scope of the claims below and the description abstract and drawings not to be used to limit the scope of the invention all of the references cited herein are expressly incorporated by reference the discussion of any reference is not an admission that it is prior art to the present invention.