Experimental study of the effect of crystalline aluminum oxide nanofibers on the properties of oil-based drilling fluids

Abstract

This work presents first-of-its kind research on the effect of alumina nanofibers (ANF) on drilling emulsions. ANF is a new generation crystalline nanofiber material with ultra-high mechanical strength and stability. From a physicochemical point of view, the material constitutes alumina nanofibers with a unidirectional dispersed structure and a faceted surface. Such characteristics provide ANF with a wide range of possibilities for interacting with various polymer matrices, as well as with ceramic and metallic materials. A number of characteristics and properties, such as viscosity, rheology, structure formation, filtration and antifriction properties, clay swelling kinetics, and stability of oil-based drilling fluids (OBDF) modified with aluminum oxide nanofibers, have been studied. These studies have demonstrated the positive effect of nanofibers on all functional characteristics of drilling fluids. It was found that nanofibers significantly change the rheological characteristics, reduce filtration losses, and reduce the coefficient of friction of drilling fluids without significantly degrading their colloidal stability in the concentration range not exceeding 1 wt%. The addition of ANF doubles the effective viscosity and yield strength, reduces filtration losses by a factor of 2.5, reduces the coefficient of friction by almost two times, and does not impair the colloidal and thermal stability of oil-based drilling fluids. This paves the way for the use of this material as the most promising one in drilling fluid development.