Influence of Polymers, Cobalt Oxide Nanoparticles, and Organophilized Palygorskite on Heat Storage and Filtrate Volume of Water-Based Drilling Fluid

Abstract The application of nanofluids has gained prominence in the oil industry, particularly in the improvement of drilling fluids. The incorporation of metal oxide nanoparticles, such as cobalt oxide, contributes to enhanced thermal, rheological, and fluid-loss control properties due to their greater thermal and chemical stability. Palygorskite clay stands out for its ability to act as a viscosifier in saline environments, forming stable suspensions. However, organophilized palygorskite may contribute to the formation of a low-permeability filter cake in water-based fluids. In this context, this study evaluates the effects of the interaction between polymers, cobalt oxide nanoparticles, and organophilized palygorskite clay in a water-based drilling fluid. The rheological properties, static filtration, and thermal performance of fluids containing cobalt oxide nanoparticles and organophilized palygorskite were investigated at different concentrations and temperatures ranging from 25 to 70 °C. The results showed that fluids containing organophilized palygorskite exhibited lower filtrate volume, while fluids containing cobalt oxide nanoparticles improved heat retention, highlighting their potential for use at lower temperatures.