(57e) New Nano-Particle Based Drilling Fluids

Data is presented in this paper that shows for the first time that it is possible to formulate water-based muds using inexpensive non-modified and commercially available silica nanoparticles and that these muds significantly reduce the invasion of water into shale. The addition of silica nanoparticles to water-based muds may offer a powerful and economic solution when dealing with wellbore stability problems in troublesome shale formations. Fluid penetration from water-based muds into shale formations results in swelling and subsequent wellbore instability. Particles in conventional drilling fluids are too large to seal the nano-sized pore throats of shales and to build an effective mud cake on shale surface and reduce fluid invasion. This paper presents laboratory data showing the positive impact of adding silica nanoparticles (particle sizes from 5 nm to 22 nm) to water-based drilling muds and their effect on water invasion into shale.