Investigation on the Mechanism and Properties of a Novel Colloidal Dispersion Gel for Profile Modification in High Salinity Reservoir

A novel colloidal dispersion gel (CDG) was synthesized by cross-linking polysaccharide-based hyperbranched polymer (SMHBP) with aluminum citrate. Four factors affecting gelation properties were investigated including SMHBP concentration, the weight ratio of polymer to cross-linker, NaCl concentration, and additive concentration. Environmental scanning electron microscope (ESEM) was used to observe the morphologies of the CDG to understand the cross-linked mechanism. The CDG is cross-linked by both intramolecular and intermolecular, and the formation of the CDG is dominated by the intramolecular crosslinking reaction. Core displacement experiments demonstrated that the novel CDG obtained excellent profile modification performances at a high temperature and high salinity.