Drill pipe or drill stems is hollow, thin-walled, steel or aluminum alloy piping that is used on drilling rigs. It is hollow to allow drilling mud fluid to be pumped down to the hole through the drilling bit.

Water well drilling rig
The drill pipe is a steel pipe with a thread at the end, which is used for connecting the drilling rig on the ground and the drilling bits at the bottom of the well.
Drill pipe must withstand enormous internally and bear external pressure, twisting, bending, and vibration.
Drill pipe can be used many times in the process of oil and gas extraction and water well drilling.
Drill stems must be designed to transfer drilling torque for combined lengths that often exceed several miles down to the Earth, and also must be able to resist pressure differentials between inside and outside, and have sufficient strength to suspend the total weight of the deeper components. For deep wells, this requires tempered steel tubes that are expensive, and owners spend considerable efforts to reuse them after finishing a well.
Model | Thickness | Thread | C1-I.D | D-wrench | K-flat | Length | Weight |
---|---|---|---|---|---|---|---|
73mm(3″) | 6.5mm | API 2 3/8″REG | 32mm | 57mm | 45mm | 3m | 40kg |
73mm(3″) | 8.5mm | API 2 3/8″REG | 32mm | 57mm | 45mm | 3m | 48kg |
89mm(3 1/2″) | 6.5mm | API 2 3/8″REG | 32mm | 70mm | 45mm | 3m | 48kg |
89mm(3 1/2″) | 8.5mm | API 2 3/8″REG | 32mm | 70mm | 45mm | 3m | 58kg |
102(4″) | 6.5mm | API 3 1/2″REG | 45mm | 83mm | 45mm | 3m | 48kg |
102(4″) | 8.5mm | API 3 1/2″REG | 40mm | 83mm | 45mm | 3m | 58kg |
114mm(4.5″) | 6.5mm | API 3 1/2″REG | 45mm | 95mm | 51mm | 3mm | 63kg |