30
2023
-
08
What is a drill collar
【Summary】The drill collar is located lower on the drill string and is the main component of the BHA. Its main characteristics are large wall thickness (generally 38~53mm, equivalent to 4~6 times the thickness of the drill pipe wall), with large gravity and stiffness. In order to facilitate the trip work, the hanger groove and slip groove can be machined on the outer surface of the inside thread of the drill collar.
The drill collar is located lower on the drill string and is the main component of the BHA. Its main characteristics are large wall thickness (generally 38~53mm, equivalent to 4~6 times the thickness of the drill pipe wall), with large gravity and stiffness. In order to facilitate the trip work, the hanger groove and slip groove can be machined on the outer surface of the inside thread of the drill collar.
Drill collars are generally divided into three types: spiral drill collars, non-magnetic drill collars, and integral drill collars.
Made of rolled or forged AISI4145H chrome-molybdenum alloy steel, the chemical composition and trace element content are effectively controlled.