Drill string
The drill string carries torque from the rig to the bit, delivers weight on bit and carries drilling fluid down the hole. Every component in it is under load from the moment it leaves the slips, so material quality, connection integrity and inspection records matter more here than almost anywhere on the rig.
Kronborr supplies drill pipe, drill collars, heavy weight drill pipe, subs and stabilizers, with traceable documentation for every joint.
The range
Seamless pipe with tool joints, in grades and connections to your program.
Heavy, thick-walled tubulars that put weight on the bit.
The transition between drill pipe and collars.
Crossover, bit and saver subs, plus string and near-bit stabilizers.
A typical string runs from drill pipe at the top, through heavy weight drill pipe as a transition, to drill collars that put weight on the bit. Subs connect components with different threads and stabilizers keep the bottom-hole assembly centred.
Getting the transition right reduces fatigue at the point where stiffness changes, which is where many string failures start.
Rotary shouldered connections carry the full load of the string. We supply components with connection type, make-up torque and inspection records documented, so your team can check them against your drilling program and inspection category.
Begin with the hole size and the loads in your program: hook load, torque, overpull margin and, for directional wells, the dogleg severity the string must pass through.
Choose drill pipe grade and connection for tension and torque, collars for the weight on bit you need, and heavy weight pipe to manage the stiffness transition. Tell us your bottom-hole assembly design and we will quote matched components.
FAQ
Drill pipe is thin-walled and carries torque and fluid through most of the string. Drill collars are thick-walled, heavy tubulars placed above the bit to provide weight on bit and stiffness.
Heavy weight drill pipe sits between drill pipe and collars. It smooths the change in stiffness, reducing fatigue, and can add weight in directional wells where collars would cause too much drag.
Yes. Every component is supplied with documentation and can be supplied with inspection records to the category your program requires. Confirm the requirement in your quote request.
Send your well program, sizes or part numbers. We reply with a quote and a reference number.