all components in a rotary drilling assembly from the swivel to the bit. Drill Stem Testing - A method of determining the potential productivity of a subsurface formation in either open or cased hole.
n: all members in the assembly used for rotary drilling from the swivel to the bit, including the kelly, the drill pipe and tool joints, the drill collars, the stabilizers, and various specialty items. Compare drill string.
The drill stem is comprised of the drill pipe, drill collars, bottomhole assembly, and drill bit. The drilling fluid is pumped down this pipe at a desired pressure and then jetted out the bit.