Drill collar:

Terms Related to Drill collar

• Bent sub

  A short cylindrical device installed in the drill stem between the bottom-most drill collar and a downhole motor. Its purpose is to deflect the downhole ...

• Tool joint

  A heavy coupling element for drill pipe. It is made of special ahoy steel and has coarse, tapered threads and seating shoulders designed to sustain ...

• Drill string

  The column, or string, of drill pipe with attached tool joints that transmits fluid and rotational power from the kelly to the drill collars and ...

• Die collar

  N: a collar or coupling of tool steel, threaded internally, that can be used to retrieve pipe from the well on fishing jobs; the female ...

• Drill stem

  All members in the assembly used for rotary drilling from the swivel to the bit, including the kelly, drill pipe and tool joints, drill collars, ...

• Drill pipe pressure gauge

  An indicator, mounted in the mud circulating system, that measures and indicates the amount of pressure in the drill stem. See drill stem.

• Kelly

  The heavy steel member, three-, four-, six-, or eight-sided, suspended from the swivel through the rotary table and connected to the topmost joint of drill ...