Sustainable Drilling Fluids Additives Development from Biodiesel

Abstract In the process of oil and gas wells drilling, the drilling fluid is an indispensable element. The drilling mud or drilling fluid is circulated during the entire operation of drilling until the completion of the well. Drilling fluid is used to perform several functional tasks such as providing density, hydrostatic stability, viscosity, lubricating bit and downhole tools, cooling down bottom hole assembly, carry cuttings to surface, hole cleaning, shale stabilization, wellbore strengthening, etc. There are several additives or chemicals added in drilling fluid in order to perform the above mentioned functional tasks. Development of environment friendly chemicals that are biodegradable and sustainable to achieve the functional tasks mentioned above is an important approach taken to reach sustainability thereby reducing carbon footprint. In addition to that, it makes the drilling fluid compatible or suitable for drilling aquifers and offshore environments. Currently, many fatty acid based products play a vital part for the development of additives or chemicals in drilling fluids. Because fatty acids offer sustainable and biodegradable properties with environment friendly characteristics. Conventionally, tall oil fatty acid (TOFA) is the major source of fatty acids that are used to derive fatty acid based products. Vegetable oil is a great source of fatty acids as it has triglycerides present in vegetable oil. Used or waste vegetable oil could serve as a perpetual and sustainable source of raw material for various types of fatty acids development which are eco-friendly. With simple processing and chemical treatment, the waste cooking oil could be converted to usable fatty acid derivatives that can be used for drilling fluid applications. The fatty acid mixture derived in this process are eco-friendly, bio-degradable and non-toxic. Owing to positive practical, technical, economical and environmental aspects, we have performed a number of research works covering different areas of application in drilling fluids for oil and gas field applications. The developed fatty acid mixtures used primarily studied as lubricants to reduce torque and drag in water based mud. By reducing torque and drag, the wear and tear of downhole bottom hole assembly could be reduced. In the case of oil-based mud systems, fatty acid mixtures are studied for applications as primary emulsifiers and rheology modifiers. In the paper, we have discussed the study of fatty acid mixture obtained from chemical conversion of used cooking oil for applications as lubricant for water-based mud and emulsifier and rheology modifier for invert emulsion oil-based mud systems. This paper explains the synthetic process of fatty acid mixture by chemical process for converting used vegetable oil to fatty acid mixtures by basic hydrolysis. Application in oil and gas drilling fluid applications have also been studied and discussed.