APPLICATION OF EXTENDED REACH DRILLING TECHNOLOGY IN THE DEVELOPMENT OF BOHAI QK17-2 OILFIELD

Extended reach drilling is an advanced technology mainly used in offshore. In the development of Bohai QK17-2 Oilfield, four extended reach wells are successfully drilled in the eastern district from the platform located in the western. The average TD and VD reaches 4551m and 2008m respectively, and the average horizontal displacement is 3668m, with average hole deviation of 86° and horizontal depth to vertical depth ratio of 1.83. It is the first time to use extended reach drilling technology to drill more than one well in Bohai Bay. A series of advanced technologies are applied, e.g., horizontal open hole gravel packing, cementing technology for horizontal and highly deviated well, whipstocking in upper loose and soft formation, precise well trajectory control, wellbore stability and hole cleaning in water base drilling fluid, casing floating, casing wearing protection, MWD/LWD measurement, torque and friction prediction programs, etc. Troubles experienced are also discussed, such as drilling off the original hole and pipe sticking.