Apparatus for reducing annular back pressure near the drill bit
OwnerVernon T. Richeyinventor
Life of this patent
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Abstract
An apparatus adapted to be connected in a drill string is disclosed. It utilizes an axially located turbine which is driven by the mud flow through the drill string. The turbine is supported by a shaft and connected to an appropriate gear train. The gear train rotates an outer sleeve which has multiple turns of an external screw thereon. The screw or helix extends toward the wall of the drill bore. The helix lifts the column of mud in the annular space above the drill bit away from the drill bit thereby reducing the back pressure just above the drill bit. This improves the jetting action of the mud pumped through the drill bit and provides for a more rapid excavation of the immediate vicinity, thereby increasing the rate of penetration of the drill bit.
Claims10
An annular mud pump for use in a drill string in drilling a well bore which is adapted to be located above the drill bit in the drill string and which comprises:
- an elongate tubular member adapted to be connected in a drill string at the upper end and further adapted to be located above a drill bit attached at the lower end of the drill string;
- a second tubular member positioned concentrically about the first tubular member;
- motor means in said first tubular member, said motor means being positioned and exposed to the flow of mud therethrough flowing through the drill string and said tubular member, said motor means having a set of blades which are rotated by the mud flow and which rotates an output shaft;
- gear means connected to the output shaft of said motor means;
- a gear connected to said second tubular member and comprising a portion of said gear means said gear being fixed to said outer tubular member for rotating the second tubular member in response to operation of said motor means;
- and
- a multiflite screw on the exterior of said second tubular member which is rotated in the annulus of the well bore in a direction to lift drilling mud by the flites of the said screw.
Dependencies are inferred from the claim text.