ENHANCEMENT OF OIL AND GAS RECOVERY USING NOVEL BIOPOLYMERS

THERE IS A NEED FOR NOVEL WATER-SOLUBLE BIOPOLYMERS THAT TOLERATE LONG-TERM EXPOSURE TO TEMPERATURES EXCEEDING 90 DEGREES CENTIGRADE FOR USE IN ENHANCED OIL RECOVERY. THESE CONDITIONS ARE ENCOUNTERED IN DEEP WELLS. THE BIOPOLYMERS EXHIBIT A COMBINATION OF OTHER USEFUL PROPERTIES, I.E., VISCOSITY RETENTION AT HIGH TEMPERATURES, GOOD SOLUBILITY IN HARD BRINES, LOW ABSORPTIVITY IN ROCK FORMATIONS, AND LACK OF SUSCEPTIBILITY TO ENZYMATIC ATTACK. PHASE I WILL COMPRISE SYSTEMATIC PREPARATION OF A SERIES OF CHITIN AND CHITOSAN DERIVATIVES TO PRODUCE AN ARRAY OF STRUCTURAL TYPES WHICH VARY AS TO ADD-ON LEVEL AND NATURE OF SIDE CHAIN SUBSTITUENTS. CHEMICAL MODIFICATIONS WILL FOLLOW CLASSIC BASE CATALYSED WILLIAMSON ETHER SYNTHESIS USING ALKYL HALIDES OR EPOXIDE TYPE AGENTS OR DIFUNCTIONAL LINKING AGENTS SUCH AS EPICHLOROHYDRIN. CONCURRENT WITH THIS SYNTHESIS OF DERIVATIVES, A SYSTEMATIC ASSESSMENT OF PROPERTIES WILL BE UNDERTAKEN USING SET PROTOCOLS TO STUDY HEAT TOLERANCE, SOLUBILITY IN BRINES AT VARIOUS PHS, ABSORPTIVITY IN ROCK, VISCOSITY AT ELEVATED TEMPERATURES, AND BIOSTABILITY. PHASE II WILL DEVELOP PRODUCTION METHODS FOR SELECTED DERIVATIVES AND TEST POLYMERS IN SAND PACKS; THESE WILL BE FOLLOWED BY FIELD TESTS CONDUCTED JOINTLY WITH A MAJOR OIL PRODUCER.