Polyacrylamide and its derivatives for oil recovery

"Polyacrylamide is an umbrella term used to describe the homo-polymer of acrylamide and the copolymer of acrylamide with a small amount of other monomers. Owing to their superior property on increasing viscosity and gelling ability in the presence of crosslinkers, polyacrylamides has become the primarily selection for polymer flooding and gel treatment agent in enhanced oil recovery. Recent developments, performance, applications and limitations of polyacrylamides and its derivatives, including copolymers and hydrogels for enhancing oil recovery are reviewed.A water-free suspension system was developed to synthesize PAMs and PAMs-microgel. Products are dry particle powder and ready to disperse in water. Compared to traditional methods, less surfactant was consumed, and the required energy cost post-treatments, like drying, were not necessary. Hydrophobically modified PAMs and PAM microgels were prepared through this method. Their structures and properties were characterized. The pore modeled oil recovery performance of the microgel was evaluated through a membrane filtration system.A biocompatible high-strength hydrogel: polyacrylamide/poly (vinyl alcohol) hydrogel with interpenetrating network (IPN) was prepared by in situ free radical solution polymerization/crosslinking of acrylamide and N, N'-methylene-bisacrylamide, as well as chemically crosslinking of PVA with glutaradehyde. Flory-Rehner theory of swelling equilibrium including the ideal Donnan equilibria has been utilized in studying the swelling and mechanical strength of the IPNs. Good linear relationship between the loading of PVA and the effective crosslinking density/strength of the IPN hydrogels had been observed"--Abstract, page iv.