Evaluation of Sawdust and Coconut Fibers as Eco-Friendly Additives for Oil-Based Drilling Muds

Abstract Drilling muds are critical fluids used in oil and gas drilling operations to lubricate the drill bit, maintain wellbore stability, and control formation damage. oil-based drilling mud is use mostly because of its shale-inhibition properties but require additives to optimize key mud properties. Conventional additives used for this purpose such as carboxymethyl cellulose (CMC) and polyanionic cellulose (PAC) are expensive and imported. This has created a need to evaluate more affordable and locally sourced alternatives. This thesis assesses the performance of composite mixtures of sawdust and coconut fiber as functional substitutes for conventional polymers in oil-based drilling muds. The evaluation compared the impact of different combination ratios of the two materials on key mud properties including rheology, density, pH, and fluid loss control. The properties of the individual component and composite mix were compared against a control mud and CMC. The composite mix was prepared in three different combination ratios of sawdust to coconut fiber - 50:50, 75:25, and 25:75. The combinations were added at 5g concentration to 250ml diesel and 100ml water to formulate an oil-based mud. Results showed that the 75% sawdust and 25% coconut fiber ratio provided the lowest fluid loss of 8.1ml among the composite samples tested. This was only 2.1ml higher than the fluid loss of 6ml achieved by 2.5g of CMC. This indicates the composite mix can produce similar effect like CMC for fluid loss control in oil-based muds. Additionally, the study evaluated the effect of the composite mix on other key mud properties like pH, density, and rheology in oil-based drilling muds. The findings showed that the composite additive positively enhanced these properties as well but had negligible effect at increasing the density of the oil-based mud. In conclusion, the locally sourced composite mix of sawdust and coconut fiber shows promise as an effective and affordable filtrate loss control agent and oil-based mud additive to replace imported polymers like CMC and PAC in drilling operations. Further testing and optimization are recommended to determine its suitability for field application.