THE EXPERIMENTAL EFFECT OF CONTAMINANT IN WATER BASED DRILLING FLUID

The oil and gas industry is extremely risky and difficult, necessitating the safe and cost-effective execution of all operations. A drilling operation's success depends on the careful selection and application of drilling fluid. Investigating how contaminants affect the properties of water-based drilling fluids is the main goal of this study. This experiment revealed that the fluid loss into the formation was enhanced when sodium salt was present in the mud system. Additionally, as the mass of the mud sample increased from 1g to 5g, the apparent viscosity and gel strength increased, but the plastic viscosity and pH stayed constant. On the other hand, the yield point showed minimal growth. Since the amount of cement sample used was increased from 1g to 5g while the pH remained constant, all rheological properties of the mud increased significantly when cement was used as a contaminant. The carbonate effect is largely on the Gel strength which decreased as the amount of added carbonate increased. The pH had no charges, which also meant carbonate kept the mud in its alkaline state, as it was the case with cement. In conclusion, the presence of a contaminant on the drilling mud either reduces or increases the rheological properties of the mud sample. This in turn affects the rate of penetration, its performance and also could pose serious drilling problems.