1、Heavy weight Drill pipe is one drilling tool which has a medium-weight and similar to drill pipe. Wall thickness is larger than that of the drill pipe, and it is smaller than drill collar. Generally add between the drill pipe and drill collar when compose the drill string, to prevent mutation of cross section of drill string, and reduce the fatigue of drill pipe. When used in directional well, it can drill with high speed under the condition of lower torque, which reduce the wear and tear of the drill string. Due to the small sidewall contact area, it is not easy to form differential pressure sticking.
2、Structure type of heavy weight drill pipe: integral, and integral-spiral.
3、Heavy weight Drill pipe can be welding hardbanding on joint or middle upset on heavy weight drill pipe (Optional)
4、Product standards: API 7-1, API7-2, NS-1