On the influence of multi-walled carbon nanotube additives on the rheology of hydrocarbon-based drilling fluids

The paper presents the results of experimental studies on the effect of multi-walled carbon nanotubes (MWCNTs) additives on the viscosity and rheological characteristics of drilling emulsions based on mineral oil. The formulations of typical drilling fluids containing 65% hydrocarbon phase were modified with nanotubes. The mass concentration of nanotubes in emulsion varied from 0.1 to 0.5%. The formulation and method of preparing stable drilling emulsions with MWCNT additives have been proposed. The rheology of drilling emulsions modified with MWCNTs was studied. The dependency of rheological characteristics on the nanotubes concentration was obtained. In general, MWCNT additives can significantly alter the rheological characteristics of drilling hydrocarbon emulsions at lower concentrations compared to the additives in the form of spherical nanoparticles. This is very important for their practical use in industry. The optimal concentration of MWCNTs for controlling the rheological properties of drilling emulsions is about 0.25 wt. %.