Drilling Technology for Ultra-Deep Directional Wells in the Halahatang Area

In order to solve the technical problems that include slow buildup rate and hard well trajectory control in ultra-deep directional drilling in the Halahatang Area of the Tarim Oilfield,we investigated well trajectory control and ROP-increasing technologies for ultra-deep wells.By analyzing difficulties in ultra-deep directional drilling technology,and studying the buildup section trajectory control and the ROP-increasing technology,a technical program was developed.The program tested the PowerDrive Archer rotary steerable system (RSS) in the buildup section of φ241.3 mm hole in ultra-deep directional well for the first time in this area.A motor with medium to low RPM and high power was selected,and combined with anti-shock and anti-abrasion 6-blade PDC bit and high temperature resistant MWD instrument in BHA to control the hole trajectory and raise ROP in φ171.5 mm inclination holdup section.By selecting a drilling fluid system that prevents lost circulation and well kick,and blocks the effects of sulfur and high temperature,safe operation in ultra-deep directional well was guaranteed.Field tests were conducted in four ultra-deep directional wells in the Halahatang Area,the average ROP in inclined section was increased by 13.53%,the average directional drilling period was shortened by 38.58%.The composite technology based on the operability in build-up and hold-up sections can be used as a reference for trajectory control and ROP increase in ultra-deep directional wells of the Halahatang Area in the Tarim Oilfield.