Gel formation of polyacrylamide in the presence of glyoxal for water control application

Abstract

A gel system based on non-hydrolysed polyacrylamide and glyoxal was developed for water control application in petroleum industry. The phase diagram at 40°C was established, which showed a stable gel region. The boundary polymer concentration for gelation was around the overlap concentration $\text{C}{}^{\mathrm{\ast }}$. The kinetics of gelation were investigated by means of viscoelasticity measurement (storage modulus G′). The gelation was more rapid with increasing temperature. The apparent activation energy ΔE_a was about 70 kJ/mol. Also, the gelation was accelerated by OH^- and the mechanism of two-step reaction was proposed.