Improvement of Polymer Gel by Magnesium Oxide for Restraining Excess Water Production
Annotatsiya
ABSTRACT Excessive water production is a significant challenge in mature oilfields, leading to reduced oil recovery and increased operational costs. This study aimed to develop and evaluate a novel nanocomposite polymer gel with enhanced thermal stability and plugging performance by incorporating magnesium oxide (MgO) nanoparticles into a standard polyacrylamide (PAM)‐chrome acetate system. The base gel formulation was first optimized to achieve a controllable gelation time of approximately 10 h. The colloidal stability of MgO nanoparticles in the polymer solution was assessed, identifying 250 ppm as the optimal concentration to prevent agglomeration. The synthesized nanocomposite gel was then systematically compared to the base gel. Rheological analysis revealed that the MgO nanoparticles increased the gel's storage modulus ( G ′) by 150%, indicating a significantly stronger and more rigid network. Under simulated harsh reservoir conditions (110°C, 2000 psi, 110,000 ppm salinity), the nanocomposite gel exhibited exceptional stability, with syneresis reduced from 70% in the base gel to just 10% after 2 months. Core flooding experiments confirmed its superior performance; the nanocomposite gel achieved a residual resistance factor (RRF) of approximately 3700, retaining over 90% of its initial plugging efficiency, whereas the base gel failed completely with an RRF below 70. These results demonstrate that MgO nanoparticles act as effective multifunctional crosslinkers and reinforcing fillers, creating a durable and highly effective gel system for long‐term water shutoff in demanding reservoir environments.