Sustainable and Eco-Friendly Drilling Fluid Additives Development

Abstract

Abstract Drilling fluid is an inseparable component of drilling oil and gas wells and circulated from the day of spudding to the day of completing a well. Drilling fluid consists of a variety of chemicals to provide various properties to drilling fluid such as viscosity, fluid loss control, emulsion stability, lubricity, etc. Developing chemicals that are eco-friendly and sustainable to provide the above-mentioned properties to drilling fluid is a significant step forward taken towards sustainability and reducing carbon footprint besides suitability for aquifers and offshore environments. Several fatty acid-based products play a crucial role in drilling fluids additives development as fatty acids offer eco-friendly and bio-degradable properties. Triglycerides present in vegetable oil is a potential source of fatty acids and their derivatives. Used cooking oil (UCO) provides a perpetual and sustainable source of raw material for various types of eco-friendly additives development. Used cooking oil is subjected to simple chemical modification of base hydrolysis process and mixture of fatty acids have been obtained after completing a sequence of clean-up process of reaction mixture. The fatty acids obtained are eco-friendly, bio-degradable and non-toxic. Due to technical, economic and environmental benefits, we have conducted several research projects to develop various chemicals from used cooking oil for oil and gas field applications. Fatty acid-based products mainly used in drilling fluids as lubricants to reduce torque and drag for water-based mud. In case of oil-based mud systems, fatty acid derived products are used as emulsifiers, wetting agents and rheology modifiers. However, these products have been either mixture of fatty acids and their derivatives or only derivatives of fatty acids. In our study, we have used the mixture of fatty acids obtained from chemical conversion of UCO for applications as lubricant for water-based mud and emulsifier and rheology modifier for invert emulsion oil-based mud systems. This paper describes the chemicals process for converting used cooking oil to fatty acids by base hydrolysis reaction in the first section. Application of synthesized fatty acids for water-based and oil-based mud formulation as lubricants, emulsifiers and rheology modifiers have been discussed in the second part of the paper.