Formulation and Performance Evaluation of Environmentally Friendly Oil Based Mud Using Palm Kernel and Limonene Oils

Drilling operations are impossible without the use of drilling mud. However, the commonly used oil for oilbased mud is diesel, but studies have shown it is toxic, which adversely impacts the environment. Hence the need for alternative oils which possess low toxicity and are biodegradable. Past works have shown that plant oil can be used to formulate competent environmentally friendly oil-based muds. In this study, three different oil samples were investigated; Palm kernel oil (PKO), a blend of Limonene oil with PKO and diesel oil which was our control sample. The physiochemical properties, rheological properties, sand content, pH, fluid loss, cake thickness and cutting carry index (CCI) of the formulated mud samples were tested and compared. The blend of limonene oil with palm kernel oil influenced the physiochemical properties of palm kernel oil, as its density and viscosity were increased. The Rheological behavior of the three mud samples were characterized using the Power Law Model where the Flow behavior index (n) were all less than 1, thus indicating that they were all pseudo plastic fluids, which is desirable for drilling fluids. PKO mud and the blend of limonene/PKO mud had better results when compared to diesel-based mud. The former had higher mud densities of 8.9ppg each, less than 0.25% sand content, pH level of 8 and 9 respectively, which is within the required API standard range, filtrate volumes of 37ml and 32ml, lesser mud cake thickness of 1.5mm and 1.2mm respectively, and a higher CCI. Limonene/PKO mud gave the best result, proving that blends of plant oils can be combined in formulating a competent drilling fluid. Finally, this study has proven that PKO and a blend of limonene with PKO are suitable for drilling and can be used in place of diesel oil.