X-ray computed microtomography studies of disproportionate permeability reduction

X-ray computed microtomography was used to understand why a Cr(III)-acetate-HPAM gel reduced permeability to water 80-90 times more than that to oil in strongly water-wet Berea sandstone and in strongly oil-wet porous polyethylene. During oil flow after gel placement in Berea, a 55% (avg) reduction in gel volume occurred in pores of all detected size ranges, thus leading to a relatively high permeability to oil. In porous, polyethylene, reduction in gel volume occurred mainly in small pores. Injection of the 20-cp gelant mobilized oil, decreasing the oil saturation for polyethylene and increasing the oil saturation for the image volume for Berea. This is an abstract of a paper presented at the SPE-DOE 14th Improved Symposium Oil Recovery Proceedings (Tulsa, OK 4/17-21/2004).