| abstract |
THE INVENTION IS DIRECTED TO STABLE CROSSLINKED WATER-SOLUBLE SWELLABLE POLYMERS AND METHODS FOR MAKING SAME. MORE PARTICULARLY, THE INVENTION RELATES TO A COMPOSITION COMPRISING EXPANDABLE POLYMERIC PARTICLES HAVING ANIONIC SITES AND LABILE CROSSLINKERS AND STABLE CROSSLINKERS, SAID PARTICLE MIXED WITH A FLUID AND A CATIONIC CROSSLINKER THAT IS CAPABLE OF FURTHER CROSSLINKING THE PARTICLE ON DEGRADATION OF THE LABILE CROSSLINKER AND EXPOSURE OF THE ANIONIC SITES SO AS TO FORM A GEL. A PARTICULARLY IMPORTANT USE IS AS AN INJECTION FLUID IN PETROLEUM PRODUCTION, WHERE THE EXPANDABLE POLYMERIC PARTICLES ARE INJECTED INTO TARGET ZONE AND WHEN THE HEAT AND/OR PH OF THE TARGET ZONE CAUSE DEGRADATION OF THE LABILE CROSSLINKER AND THE PARTICLE EXPANDS, THE CATIONIC CROSSLINKER CROSSLINKS THE POLYMER TO FORM A GEL, THUS DIVERTING WATER TO LOWER PERMEABILITY REGIONS AND IMPROVING OIL RECOVERY. NO SUITABLE |