Systematic experimental study of the temperature dependence of viscosity and rheological behavior of water-based drilling fluids with nano-additives

The paper presents the results of a systematic study of the influence of nano-additives of various concentrations, average sizes and composition on the temperature dependence of the viscosity and rheological behavior of water-based drilling fluids. Typical compositions of drilling fluids, such as water suspensions of various clay solutions and gammaxan-based polymer solutions, were considered. Hydrophilic nanoparticles of silicon and aluminum oxides were used as nano-additives at concentrations ranging from 0.25 to 3 wt%. The average nanoparticle size varied from 10 to 151 nm. The temperature of drilling fluids varied from 25 degrees C to 80 degrees C. It is shown that the addition of nanoparticles to drilling fluids leads to a significant change in their rheological properties depending on the temperature. It was found that with increasing temperature, the yield stress and consistency index of drilling fluids with nanoparticles increase, while the behavior index, on the contrary, decreases. This behavior depends on the size of the nanoparticles. As the particle size increases, their influence on the temperature dependence of the drilling fluids' viscosity increases. In general, it is shown that the addition of nanoparticles makes the viscosity of drilling fluid more stable with regard to the temperature. This is an essential fact for practical application. (c) 2022 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).