ABSTRACT
The exploration and production of oil and gas wells is greatly impacted by the selection of drilling fluids. Drilling fluids perform several functions including cooling and lubrication of the bit, prevention of formation damage as well as lifting and transportation of drilled cuttings. The components of a drilling fluid which include base fluid, weighting agents, surfactants, viscosifiers, elmusifiers, etc., aids the drilling fluid in performing its required functions. In Nigeria, creative and innovative approaches are required for oil and gas exploration and exploitation, in order to improve local content while considering factors such as availability, cost and ecological impacts, amongst others. This study aims to investigate the efficacy of two different additives, Xanthan gum, a biopolymer and Cassava starch a natural polysaccharide, in improving the rheological properties of water based mud. These properties, including viscosity, yield point and gel strength, are crucial factors in determining the performance of drilling fluid in oil and gas exploration. In this study, laboratory experiments were carried out. Individual Xanthan gum concentrations of 0.5g, 1.0g and 1.5g and Cassava starch concentrations of 5g, 10g and 15g were added to a base fluid of fixed volume of 350ml of water and fixed concentration of 22.5g of Bentonite. From analyses of the experimental results, Xanthan gum proves to be more effective than cassava starch for improving the gel strength, plastic viscosity and yield point of water based mud.
