Development of Polymer Gel for Severely Fractured Geothermal Systems

In geothermal systems, polymer injection is vital for improving the sweep efficiency of fluid, but the critical challenge is managing the fluid flow in severely fractured systems. Developing stable plugging agents for these systems is a recurring challenge, allowing the loss of the fluid into the large fractures, hence making the recovery very difficult. The fluid is crucial for several applications like power generation, heating, and cooling without producing any toxic emissions. This study presents a gel system formulated with hydroxyethyl cellulose, and a HMTA–resorcinol crosslinker system for harsh conditions of temperature and salinity. The study employed a Central Composite Design (CCD) for optimizing gel formulation. The system achieved optimal conditions at a gelation time of 0.5 h, and the properties were investigated. The experimental outcomes reveal that the polymer gel can exhibit excellent stability under harsh conditions, withstanding temperatures up to 352 °C. This confirms the robustness of the plugging agent at elevated temperatures. This study offers a sustainable and efficient solution for fluid flow control in severely fractured geothermal systems.