Drill pipe

Drilling Equipment & Components

Drill pipe constitutes the majority of the drillstring length. It is seamless steel pipe with threaded connections (tool joints) on each end. It transmits torque and hydraulic fluid to the bit while connecting the surface equipment to the BHA.

Drill pipe must withstand complex cyclic loading—tension, compression, torsion, and bending. It is graded by strength (e.g., G-105, S-135) and size. Managing drill pipe fatigue is a major part of drilling engineering, as washouts (cracks) can lead to twist-offs and costly fishing jobs.