Study of nano-SiO2 Strengthened High-Molecular-Weight Polymer Gel for Plugging Steam Channeling

As for steam channeling often occurred in the late stage of multiple rounds of the cyclic steam, it is necessary to investigate plugging agent with excellent performance. Aiming at the problems of poor stability (less than 30 days) of HPAM gel as a plugging agent at 150 ℃, a nano-SiO2 strengthened polymer phenolic gel with good thermal stability by using HPAM with a molecular weight of 1.8 × 107 was investigated. The ideal formulation of the gellant was selected from the mass amount of polymer, cross-linker, and the nano-SiO2 particles. The thermal stability and application performance were also be evaluated. The experimental results showed that when the gel was prepared with 0.3% HPAM, 1% water-soluble phenolic resin as a cross-linker, and 1% nano- SiO2 as a stabilizer, the dehydration rate was less than 5% after being aged for 150 days at 150 ℃. Dynamic light scattering experiments (DLS) results showed an increase in the hydrodynamic radius and stability at high temperatures of the polymer solution after the addition of nanoparticles The results of rheological experiments showed that the addition of nanoparticles significantly increased the viscosity retention of gellant, gel's yield stress and long-term thermal stability without affecting the viscosity of the gellant.