Local plant seed oils (Esters): The frontier of geothermal drilling applications – A review

Abstract

A typical oil well may generate between 1 000 and 1 500 tonnes of drilled cuttings with average oil retention of 15% which are generally discharged into the sea. This activity affects vast areas around the drilling sites especially if the drilling fluids are formulated from conventional oil based fluids. Most mineral oils, diesel, petrochemical synthetic fluids have become a threat to the environment because of their high level of toxicity and cost of containment, hauling, and disposal. Many base oil fluids have been developed over the years to address these challenges but with very little successes. Plant esters have the potential to be used as drilling fluids as they meet the economic, technical and environmental requirements of the American Petroleum Institute (API). The use of plant esters can help alleviate challenges such as ill-health problems faced by workers, boost nutrients in soils if discharged onshore and help drill through troublesome formations safely. This paper reviews the potential use of plant esters as an economically viable, technically acceptable, environmentally friendly and sustainable oil based fluid substitute for the drilling of high geothermal wells.