Characterization of a New Vegetable Oil Based Ester Drilling Fluid

This thesis presents a novel base fluid material for synthetic based drilling fluid systems. The proposed vegetable oil based ester material is biodegradable in both aerobic and anaerobic conditions as shown by the plate test and the UV spectrophotometric analysis. It is also highly cost effective and fairly easy to synthesize. The vegetable oil ester material is an insulator and has been modified using nanoparticles to adapt to the resistivity measuring devices. Good sensing properties were observed in the presence of additives like ferric nitrate with a drastic reduction of 90 % in the resistivity. The optimum formulation of the proposed drilling fluid comprising minimal number of eco-friendly additives was determined by experimental results. An in situ made UH-Biosurfactant being a major component of the proposed drilling fluid blends the invert emulsion improving its emulsion stability and also helps in reducing ester hydrolysis when tested at a temperature of 75 oC. Though the proposed material is affected by salt contamination, addition of a trivial amount of 0.1-0.5 % of nanoparticles would negate the effects of salt contamination of the drilling fluid. Even otherwise, incorporation of at least 0.5 % of nano materials would reduce the fluid loss by over 90 %. The UH-Biosurfactant which enhances the properties of drilling fluid with a nominal quantity of 1 % is produced in a microbial fuel cell which recycles the used ester; hence proving to be a completely sustainable system. A hyperbolic model was developed to predict the shear behavior.Civil and Environmental Engineering, Department o