Dual-network microgels system with thermal crosslinking behavior for high-temperature steam channeling control in heavy oil reservoirs

Abstract

Heavy oil development faces challenges due to high viscosity and steam channeling during thermal recovery. Conventional plugging agents like foams and gels often suffer from thermal instability and low injectivity. This study developed a thermally crosslinkable dual-network microgel system (3AC-PL) for steam channeling control. The system consists of polymer microgels-synthesized from acrylamide (AM), 2-acrylamido-2-methylpropanesulfonic acid (AMPS), α-olefin sulfonate (AOS), and carboxymethyl cellulose (CMC)-and crosslinkers including polyethyleneimine (PEI) and L-lysine hydrochloride (Lys-HCl). Characterized by FTIR, SEM, TG-DSC, and rheology, 3AC-PL demonstrated controlled swelling, excellent thermal/salt resistance, and strong viscoelasticity between 130–160°C. Microfluidic experiments confirmed that the microgel effectively blocked high-permeability channels, diverted steam into low-permeability zones, and increased oil recovery from 63.53 % to 95.20 %. Molecular dynamics simulations further revealed sequential crosslinking mechanisms and the role of hydrogen bonding in network stability. This work presents a promising dual-network microgel system that integrates molecular-level understanding with practical performance, offering an effective solution for managing steam channeling in high-temperature heavy oil reservoirs.