| 摘要 |
A self-stabilizing drill collar structure for incorporation into a drill string for deep well rotary drilling includes an elongated cylindrical collar member having an axially extending throughbore for passing drilling fluid downwardly to the lower end of the drill string. An arrangement of easily replaceable and non-fouling nozzles located within slots and protected by the wall of the collar serve to divert clean downwardly flowing drilling fluid from the axial throughbore and discharge it in a jet-like manner laterally outward from the opposite ends of the slots into the annular gap between the collar and bore hole to thereby improve lubrication of the gap and provide better circulation and return of the drilling fluid to the surface for re-cycling, and which enables the drilling to take place at a higher speed and with greater accuracy and stability as regards the desired course of the bore hole. The number of nozzles in operation can be varied as desired by replacing one or more of them with plugs and the collar member can also be provided optionally with reaming flanges to shape the bore hole.
|
