| abstract |
Improved oil recoveries, where the reservoir is flooded with a REM (recovery enhancing material) followed by a mobility control polymer, are obtained by either preceding the injection of the REM with a PCA (polymer conserving agent) or incorporating the PCA in a portion of the REM. The PCA, then, preferentially adsorbs onto available adsorption sites within the subterranean reservoir which otherwise would be occupied by the mobility control polymer. Examples of the PCA include polymers and copolymers of, for instance, acrylamide and sodium acrylate. They generally have an average molecular weight within the range of about 2000 to about 500,000. |