Preparation and Evaluation of Nanocomposite Gel Systems for Enhanced Oil Recovery

ABSTRACT

To address the challenges of insufficient mechanical strength and limited environmental adaptability of conventional preformed particle gels (PPGs) under harsh reservoir conditions, a nanomaterial‐reinforced preformed particle gel (NR‐PPG) was developed in this study. NR‐PPG was synthesized through aqueous copolymerization of sodium acrylate (NaAA), 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), and 4‐acryloylmorpholine (ACMO) using KH570‐modified nano‐silica as a reinforcing component. The incorporation of nano‐silica and the synergistic effects of ionic and nonionic monomers endowed NR‐PPG with enhanced structural stability and environmental adaptability. The synthesized NR‐PPG was characterized by FTIR, SEM, and DLS, confirming the successful modification of nano‐silica and its uniform dispersion within the polymer network. The optimized NR‐PPG exhibited stable swelling behavior over a wide range of pH, salinity, and temperature conditions, maintaining excellent swelling capacity under simulated reservoir conditions (120°C and 1 × 10 ⁴  mg/L salinity). Rheological analysis revealed a predominantly elastic response and stable three‐dimensional network structure. Moreover, NR‐PPG achieved a compressive strength of 2422.6 kPa, elongation at break of 2404%, and tensile strength of 147 kPa, demonstrating a combination of high strength and toughness. These results indicate that NR‐PPG is a promising candidate for high‐temperature and high‐salinity oilfield water shutoff applications.