Double‐Network Preformed Particle Gel Based on Hydroxypropyl Methylcellulose and Hydrophobic Association for Conformance Control in Low‐Permeability Fractured Reservoirs

Abstract

The conventional preformed particle gel (PPG) has certain problems of relatively poor strength and easy shear crushing after swelling during the in‐depth conformance control process in low‐permeability fractured reservoirs. Herein, a novel double‐network PPG (DN‐CPPG) based on biopolymer (hydroxypropyl methylcellulose, HPMC) and hydrophobic association (C16 hydrophobic chain) was synthesized using a radical polymerization approach. The chemical structure, microscopic morphologies, and thermal tolerance were first characterized. Then, the swelling property, dynamic viscoelasticity, yield stress, and creep recovery ability of DN‐CPPG were systematically investigated. The results revealed that the DN‐CPPG exhibited an average diameter (d50) of approximately 27.12 μm and considerable thermal stability. Furthermore, it displayed superior viscoelastic properties, yield stress, and creep recovery behavior after the equilibrium swelling process compared to conventional PPG. This was attributed to the synergistic effects of newly developed DN and hydrophobic association, resulting in a tightly crosslinking network and strong gel strength. In addition, the DN‐CPPG exhibited excellent mechanical strength, with higher fractured stress (278 kPa) and elongation strain (917%) compared to those of PPG (140 kPa and 666%) during the strain–stress sweep experiments. This newly formulated DN‐CPPG serves as a promising conformance control material for low‐permeability fractured reservoirs.