关键词: 可变径稳定器, 大位移井, 钻井技术, 井下闭环, 井眼轨迹, 控制技术

Abstract: The closed-loop control of the well trajectory at downhole is the most advanced technology in domestic and overseas'drilling engineering.The technology of extended-reach well has become a main focus in the drilling technology of the petroleum industry in the world.It is necessary to depend on the control technology of borehole trajectory to drill the extended-reach well successfully.A closed-loop adjustable stabilizer at downhole is developed. The structure and principle of operation of the stabilizer,and method for controlling borehole trajectory with the close-loop adjustable stabilizer at downhole are described in detail.The close-loop adjustable stabilizer at downhole has been used in oilfield.It may provide an effective way for drilling of the extended-reach well,especially for the offshore-drilling,enhancing the rate of penetration and reducing the drilling cost.

Key words: adjustable stabilizer, extended-reach well, drilling technology, downhole closed-loop, borehole trajectory, control technique