This research work investigates into the performance of Aluminium Oxide nanoparticles in water based bentonite drilling fluid at high temperature formations. We looked into the thermal stability effect of the Aluminium oxide nanoparticles on the drilling fluid at varying temperature conditions. We analyzed the interactive effects of temperature, the Aluminium Oxide nanoparticles and shear rates on the shear stress of the drilling fluid. Optimization of these parameters at the high and low point of the shear stress of the drilling fluid was analyzed. We also developed a predictive expression for Shear stress as a response variable for changes in temperature, Aluminium Oxide nanoparticle and shear rate.