Improving Drilling Fluid Properties at High Pressure Conditions Using Selected Nanomaterials

Drilling fluids with conventional lubricants (including solid and liquid lubricants) will produce lubricant film between drill string and wellbore/casing, but this film will not be strong enough to protect the bit bearing surfaces subjected to high load conditions during the drilling operations, resulting in shortening the life of drill bit. In this research, the possibility of using nanomaterials as extreme pressure lubricants was investigated by adding different concentrations (0.02, 0.05 and 0.1) wt. %of TiO₂nanoparticles (NPs) and Cu NP into water- based mud. The lubricating film strength of water based mud samples under extreme pressure conditions were measured using Extreme Pressure (EP) and Lubricity Tester. With the purpose of getting the best performance from extreme pressure lubricants, the effect of nanomaterials on rheological (including plastic viscosity, yield point, apparent viscosity, and gel strength) and filtration (including filtrate loss volume and mud cake thickness) properties were measured. TiO₂ NPs and Cu NP showed a good enhancement in lubricating film strength under extreme pressure conditions. The maximum value of lubricating film strength increasing percentage (69.6%) was obtained using TiO₂ NPs with concentration of 0.1wt.%.