Synthesis of polyacrylamide copolymers cross-linked by chitosan hydrogels with potential application for conformance control of petroleum reservoirs

Conformance control treatment of oil reservoirs is one the techniques that can bring improvements in both sweep efficiency and reduction excessive co-production oily water. In this work, chemical conformance was studied through development gelling systems for situ hydrogel formation to act as blocking agents more permeable regions. For purpose, copolymers based on acrylamide were used, containing co-monomers acrylic acid (AA), partially hydrolyzed polyacrylamide (PHPA), or 2-acrylamide-methylpropane-sulfonic (AMPS), well terpolymer these three types (AA, PHPA, AMPS), chitosan a cross-linking agent. The preliminarily evaluated using Sydansk gel strength codes, which classify behavior hydrogels codes from “A” “J” according their fluidity. tests, scans polymer cross-linker concentration performed, verified, mechanistic proposals considered. Subsequently, viscoelastic properties materials evaluated, followed by an experimental design consisting central composite (CCD), where variables, temperature aging time hydrogels, showed statistical relevance directly strength. had optimal injection viscosity values low tan(delta) values, demonstrating desirable agents, critical stability 15 days.