Abstract

Drilling for water, oil, or even gas using water-based drilling fluids faces major challenges. These are mainly related to drilling fluid leakage into the surrounding formation, water loss into fractures, and the reduction of fluid density or/and viscosity through the drilling circulation process. Nanoadditives with high surface to volume ratio of carbon nanoparticles (CNP), ~50nm, and ZnO nanowires provide significant control of drilling fluid rheological properties. CNP additives were found to maintain the homogeneity of the drilling fluid components for a longer time and delay fluid sagging effect. Drilling fluid densities were enhanced by a factor of 4-10% after addition of CNP or ZnO nanowires to the untreated drilling fluid by 1-3 wt. %. Progressively, when 1, 2 and 3g of CNP was added to the drilling fluid, the resultant filtrate water volume was reduced by 7, 4.8 and 4mL respectively. The maximum water loss reduction measured was about 50% of the total fluid loss. Additionally, about a 24% increase in the drilling fluid viscosity was achieved when 2g of ZnO nanowires were added.