IMPROVED ENHANCED OIL RECOVERY PROCESSES USING NEW AND NOVEL SYNTHETIC COPOLYMERS CONTAINING LARGE AMOUNTS OF ACRYLAMIDE

INDEPENDENTS IN THE MID-CONTINENT AREA INCLUDING OKLAHOMA AND KANSAS, NEED A NEW AND NOVEL WATER SOLUBLE POLYMER FOR INDEPTH MOBILITY CONTROL IN ENHANCED OIL RECOVERY (EOR) PROCESSES AT INTERMEDIATE TEMPERATURES OF 165 TO 200 FAHRENHEIT. PARTIALLY HYDROLYZED POLYACRYLAMIDES AND NATURAL POLYMERS HAVE HISTORICALLY BEEN THE PRODUCTS USED IN THIS REGION. AND IN ESSENTIALLY ALL OF THE EARLIER EOR PROJECTS, IT HAS BEEN NECESSARY FOR THE OPERATORS TO USE FRESH WATER WHEN USING POLYACRYLAMIDES. THE MOST AVAILABLE INJECTION FLUID IS ARBUCKLE BRINE. MOST POLYACRYLAMIDES ARE UNSTABLE IN THE HARD BRINES IN MOST RESERVOIRS IN THE REGION DUE TO THE HIGH CONCENTRATION OF CALCIUM AND MAGNESIUM CATIONS. IN MANY CASES THE POLYMERS CANNOT WITHSTAND THE TEMPERATURES ABOVE 165 FAHRENHEIT. IN OKLAHOMA ANY EOR PROJECT USING FRESH WATER WILL NOT BE ELIGIBLE FOR THE SEVEN PERCENT EXCLUSION IN STATE SEVERANCE TAXES. IT THEREFORE BECOMES IMPORTANT FOR INDUSTRY TO DEVELOP A NEW TYPE OF WATER SOLUBLE POLYMER THAT CAN BE MIXED IN TYPICAL FIELD BRINES FOR EOR PROJECTS. PHASE I WILL COMPRISE A SYSTEMATIC PREPARATION AND TESTING OF A SERIES OF NEW COPOLYMERS WHICH HAVE THE POTENTIAL FOR SUPERIOR PERFORMANCE IN THE MID-CONTINENT RESERVOIRS. THE COPOLYMERS WILL CONTAIN LARGE AMOUNTS OF THE ACRYLAMIDE MONOMER WHICH IS LOW COST AND READILY AVAILABLE. THE SECOND MONOMER WILL BE FROM A FAMILY OF MONOMERS KNOWN TO PROTECT ACRYLAMIDE AT ELEVATED TEMPERATURES AND SALINITIES. A SYSTEMATIC ASSESSMENT OF VISCOSITIES, TEMPERATURE STABILITY, SOLUBILITIES IN BRINES AND OTHER CHARACTERISTICS WILL BE RECORDED ON THE NEW POLYMERS. PHASEII WILL DEVELOP AND OPTIMIZE THE BEST OF THE COPOLYMERS, AND TEST THEM IN RESERVOIR CORES. THIS WOULD BE FOLLOWED BYINJECTIVITY AND EOR TESTS WITH AN OIL OPERATOR.