Advancing sustainability of drilling fluid: coconut and shea butter oils as alternative to diesel

Abstract

Drilling fluid is a key element in the drilling process because it lifts cuttings to the surface, maintains a stable wellbore, and generates sufficient hydrostatic pressure to prevent the influx of formation fluids into the wellbore. While oil-based drilling fluids offer advantages like wellbore stability, lubrication, and temperature resistance, disposing of oil-contaminated cuttings, particularly those using diesel, harms the environment. This study explores the use of coconut oil and shear butter oil, a renewable and biodegradable resource, as the base for oil-based drilling fluids. Two samples of coconut oil and shea butter oil-based mud samples were formulated and tested in the laboratory against the conventional crude oil-based mud. Laboratory tests compared each sample of coconut oil and shea butter oil-based mud against conventional diesel-based mud. Tests included FTIR characterization of additives, and evaluation of gel strengths, yield point, viscosity, and emulsion stability at 120°F and 300°F. Filtration loss and mud thickness were also measured. Results indicate that coconut oil and shea butter oil-based drilling fluids offer promising rheological properties and environmental benefits. Coconut oil-based sample (VCO I) exhibited superior viscosity and emulsion stability, though it produced a thicker mud cake, indicating a need for optimization. These alternatives present a viable solution to reduce the environmental impact of drilling operations. Further research and field trials are recommended for practical application.