Evaluation of the Effect of Metal Oxide Nanoparticles in Combination with Polyacrylamide on Improving the Filtration and Rheological Properties of Drilling Fluids

Drilling fluid properties and determination of its appropriate formulation are very important for the success of drilling operations. In this study, the effect of hydrophilic silicon oxide nanoparticles and iron oxide in combination with polyacrylamide on the rheological and filteration properties of water-based drilling mud was investigated. Silica and iron oxide have been used as nanomaterials due to their abundance and economical advantages. Material characterization was performed using X-ray diffraction analysis (XRD), scanning electron microscope (SEM), and Fourier Transform Infrared Spectroscopy (FTIR). Rheological properties including plastic viscosity and gel strength were measured at different concentrations of polymer and nanoparticles. Moreover, the effect of additives on the mud filtrate and mud cake quality was evaluated. The results showed that the presence of silicon oxide nanoparticles can improve the rheology of drilling mud up to 15% at a concentration of 1 wt %. The viscosity increased due to the separation and dispersion of clay plates.  Furthermore, the results indicated that the addition of iron oxide nanoparticles did not have a significant effect on rheology. On the other hand, the addition of polymer caused a significant increase in viscosity and gel strength of drilling mud. The obtained results showed that due to the interaction of clay plates with silica nanoparticles, the gelatinous properties of drilling mud decrease at low concentrations of nanoparticles. The results of the filtration test showed that the addition of polymer and nanoparticles to the drilling mud causes a further decrease in the filtration rate at lower concentrations of the polymer. This effect is due to the clogging of mud cake pores by nanoparticles in the presence of polymer, so that with the simultaneous addition of nanoparticles and polymer, the mud filtrate was decreased from 128 cc to 14 cc.