Directional drilling headed for improvements

摘要

Nine to 11 km reach world-class ERD wells are used in the Russian Far East to develop an offshore reservoir from an onshore location. While drilling initial wells into the reservoir, high torque was experienced, even while using a non-aqueous drilling fluid. The torque was sufficiently high that concerns arose about the feasibility to drill longer wells. Consequently, finding techniques to reduce drilling torque became a major focus for the development. A systematic R&D process was initiated to solve the torque problem. The scope of the investigations included consideration of different base oils, solid/liquid lubricants and mechanical means to reduce torque. Small-scale screening lubricity testing was performed in a controlled laboratory environment to identify potential lubricant candidates. Full-sized laboratory testing was then performed on the leading products. Various mechanical means to reduce torque were also evaluated. Finally, field trials were performed using solid and liquid lubricants and different types of mechanical torque reduction tools.