Drilling technologies used in an extended reach well named Nanpu 13-1706

Due to the areal restriction of end island, it is necessary to deploy extended reach wells with the horizontal displacement over 3 000 m to develop Nanpu shallow sea oilfield of Jidong Oilfield. The drilling operation of extended reach well is faced with a series of difficulties, e.g. high torque and drag, difficult trajectory control, high circulating pump pressure, difficult hole cleaning, instable long open-hole wellbore and directional backing pressure in the deep hole section. To solve these difficulties, well trajectory was optimally designed, the equipment was upgraded and transformed so as to increase the hole extension limit of extended reach well. What’s more, the conventional technologies were optimized and integratedly applied, including well trajectory control, torque and drag reduction, drilling fluid and safe casing running. By taking these measures, an extended reach well named Nanpu 13-1706 is successfully drilled with total depth 6 387 m, maximum deviation angle of 83° and horizontal displacement of 4 941 m. The research results accumulate the experience for the drilling of extended reach wells with horizontal displacement over 4 500 m, and provide the technical support for the exploration and development of middle-deep oil reservoirs in Nanpu shallow sea.