Enhancing the Rheological and Filtration Performance of Water-Based Drilling Fluids Using Silane-Coated Aluminum Oxide NPs

For optimizing the drilling efficiency, nanoparticles (NPs) specifically nanometal oxides have been used in water-based drilling fluids (WBDF). Nano metal oxides improve the rheological and filtration characteristics of the WBDF. However, dispersion instability among pristine nano metals shrinks the performance of the nanometal oxides due to high surface energy. Therefore, this study aims to utilize silane-coated aluminum oxide NPs (S-Al₂O₃) as an alternative to widely used pristine aluminum oxide (P-Al₂O₃) in water-based drilling fluids. The S-Al₂O₃ NPs were synthesized using 3-aminopropyl triethoxysilane (APTES). FTIR, XRD, and SEM analyses were carried out to examine the crystalline structure and surface morphology of NPs. Moreover, the rheological and filtration properties of nanowater-based drilling fluids were investigated at low-pressure and low-temperature (LPLT) conditions. The results of experiments revealed that S-Al₂O₃ NPs significantly upgraded the rheological properties compared to P-Al₂O₃ NPs. The S-Al₂O₃ NPs reduced plastic viscosity from 12.6 to 9.6 cP, apparent viscosity from 34.5 to 26.5 cP, and yield point from 46.5 to 39.5 lb/100 ft². The gel strengths (10 s and 10 min) were reduced from 44.5 to 32 lb/100 ft² and from 77 to 59 lb/100 ft², respectively. Furthermore, S-Al₂O₃ NPs enhanced the filtration performance, achieving a 26% reduction in filtrate loss and forming a thinner, more impermeable mud cake than P-Al₂O₃ NPs. In conclusion, the application of S-Al₂O₃ NPs in water-based drilling fluid was found to be effective in improving the rheological properties and controlling the filtrate loss effectively under LPLT conditions. The utilization of silane-coated NPs used in this study will open new and novel doors of research in the fields of both drilling engineering and nanotechnology.