Eco-friendly Extreme Pressure Lubricants for Water based Drilling Fluids Rakshith R Shettigar 1 , Nirendra M Misra 1 , Bhaskar Naik 2 and Khushbu Patel 1 1 Department of Science, School of Technology, Pandit Deendayal Petroleum University, Gandhinagar, Gujarat, India 2 Petropath Fluids (India) Pvt. Ltd., Bangalore, Karnataka, India Abstract. Water based drilling fluids possess very high coefficient of friction as compared to oil based drilling fluids (mud). High coefficient of friction can be reduced by adding lubricating additives to the mud. Lubricating agents reduces the torque and drag produced during the drilling process. Our study involves the analysis of various eco- friendly Extreme Pressure lubricating additives which are derivatives of fatty acids, seed oil. Non-dispersed conventional mud, Non-dispersed salt water mud and Inhibitive Polymer mud systems were used as Base mud for the study. Different oil additives are added in proportion ranging from 1.75 ppb to 7.0 ppb and also in combination by formulating Extreme Pressure Lubricants. Extreme Pressure Film strength and Lubricity coefficients were carried out using OFITE Lubricity/ Extreme pressure Tester. Detailed study on rheology, cheesing/ greasing effect, Mud weight, foaming tendency, pH and performance in brine phase were also analyzed. Pure seed oil is found to be best lubricant from the set of oil samples. It showed excellent lubricity coefficient and extreme pressure film strength in all three types of mud systems. This was followed by the fatty acid derivative of the same seed oil. Keywords: Extreme pressure, lubricant, Non-dispersed, conventional mud, inhibitive, polymer mud, lubricity coefficient, film strength, rheology, cheesing, greasing, foam tendency. 1. Introduction One of the significant functions of the drilling fluids is to lubricate the bit and the stem. It is a critical function, particularly while drilling directional wells, since the frictional forces between the drill string and wellbore or casing are so significant that they can lead to several problems such as high torque and drag, which can lead to premature damage to the drilling tools, as a consequence of excessive wear and heat [1]. Lubricating additives, lubricants in drilling fluids, give typical savings in terms of: i) Increased drilling performance to Oil and Gas depth by reducing friction, less bit/pipe trips, cooler running mud motors allows for deeper wells, longer laterals and more efficient drilling options. ii) Bit Cost Savings - Reducing friction saves heat and wear on drill bits, increases the shelf life of the bit. iii) Reduced Drag- Drilling horizontal wells can cause up to 40% more drag on the top drive and mud motors. A good lubricant possesses the following characteristics: a)High boiling point, b)Low freezing point, c)High viscosity index, d)Thermal stability, e)Hydraulic Stability, g)Corrosion prevention, h)High resistance to oxidation [2] . Lubricating additives are - fatty acid derivatives, seed oil based, triglyceride based, petroleum based, poly-propylene glycol based etc [3]. Lubricating property of the oil depends upon the functional moieties present in the oil. Oxygen carrying moieties enhances the lubricity and film strength of the additive. The order of the oxygen atom carrying functional moieties -COOH > -CHO > -OH > -COOCH3 > -C=O > -C-O- C [4]. Lubricants which remain adhered to the moving parts even during high pressure and torque are  Corresponding author. Tel.: +91-79-23275421 E-mail address: Nirendra.misra@sot.pdpu.ac.in International Proceedings of Chemical, Biological and Environmental Engineering, V0l. 90 (2015) DOI: 10.7763/IPCBEE. 2015. V90. 8 51