Development and Application of Extreme-pressure Lubricant (PF-EXLUBE) for Drilling Fluid

To solve the problem of the high drag and torque in drilling extended reach wells and horizontal wells, to ensure operation safety and improve operation efficiency, based on sea-water polymer drilling fluid, an extreme-pressure lubricant using in drilling fluid, PF-EXLUBE was developed through screening and evaluating experiments of the properties of conventional lubricating and extreme-pressure of a series of lubraicants. The extreme pressure lubricator and the lubrication evaluation simulation device (LEM) were used to evaluate the lubricating properties of potassium chloride-polymer, saturated sodium chloride drilling-in fluid and potassium formate drilling-in fluid respectively.The experimental results show that when the amount of PF-EXLUBE is 1%, the friction coefficient is reduced by 33% ～95% under normal temperature conditions; the friction coefficient is reduced by 60% ～80% under high temperature and high pressure (150 ℃, 100 psi) conditions. PF-EXLUBE has been first applied in a well of the eastern South China Sea. The application results show that adding 2% PF-EXLUBE to the drilling fluid the torque of drilling could reduce by 15% ～20%, and the effect lasts for a long time. It shows good torque reduction effect.