The Preparation And Evaluation Of A High-performance Lubricant For Water Based Drilling Fluids

The problems of high drag and high torque restrict the popularization and application of water-based drilling fluid in extended-reach wells,horizontal wells,deep wells,ultra-deep wells and other complex wells.Adding lubricant to water-based drilling fluid can significantly improve the lubricating property of drilling fluid system.In this paper,a high-performance water-based drilling fluid lubricant,CUPL-1,was developed through literature research and a large number of laboratory experiments.It's developed by the use of fatty acids,polyols,extreme pressure additives and defoaming materials as raw materials.Laboratory evolution experiments results showed that 4% bentonite slurry treated with 1% of this lubricant have lubricity coefficient reduced by 86.8% to 93.9% and the adhesion coefficient of the mud cake was also reduced by about 55%,which shows the excellent lubricating properties.The lubricant also has good salt resistance,high temperature resistance and anti-wear ability.It can stably form a stable lubricating film on the contact surface to reduce wear.Drilling fluids evaluation experiments show that adding the lubricant in various water-based drilling fluids can improve the rheological properties of the system,and will not have a negative impact on other performances of the drilling fluids.In addition,it can also reduce the lubricity coefficient of the drilling fluid system and significantly improve the lubricating property of the drilling fluids.