Drill bits with anti-tracking features
AssigneeBaker Hughes Incorporated
InventorsRobert J. Buske, John F. Bradford
Life of this patent
Estimating the term…
Abstract
Drill bits with at least two roller cones of different diameters and/or utilizing different cutter pitches in order to reduce bit tracking during drilling operations are described. In particular, earth boring drill bits are provided, the bits having two or more roller cones, and optionally one or more cutter blades, the bits being arranged for reducing tracking by the roller cone teeth during operation by adjusting the teeth spacing, cone pitch angle, and/or the diameter of one or more of the cones. These configurations enable anti-tracking behavior and enhanced drilling efficiency during bit operation.
Claims34
A hybrid drill bit defining gage, shoulder, nose and cone regions comprising:
- a bit body having a longitudinal central axis;
- at least one blade extending from the bit body;
- first and second arms extending from the bit body;
- a first roller cone rotatably secured to the first arm and extending inwardly toward the central axis, the first roller cone having a plurality of cutting elements in the shoulder or nose regions;
- a second roller cone rotatably secured to the second arm and extending inwardly toward the central axis, the second roller cone having a plurality of cutting elements in the shoulder or nose regions;
- and
- wherein the first roller cone has a maximum outside diameter in the shoulder or nose regions that is larger than a maximum outside diameter of the second roller cone in the shoulder or nose regions.
A hybrid drill bit comprising:
- gage, shoulder, nose and cone regions;
- a bit body having a longitudinal central axis;
- at least one blade extending from the bit body;
- a first and second arm extending from the bit body;
- a first roller cone rotatably secured to the first arm and extending inwardly toward the central axis and having a plurality of cutting elements arranged in generally circumferential rows in at least the shoulder and nose regions;
- and
- a second roller cone rotatably secured to the second arm and extending inwardly toward the central axis and having a plurality of cutting elements arranged in generally circumferential rows in at least the shoulder and nose regions;
- wherein the first roller cone has a different cutter pitch than the second roller cone.
An earth-boring hybrid bit comprising:
- a bit body defining a central longitudinal axis;
- at least one blade extending from the body and configured to support at least one cutting element thereon;
- at least two bit legs depending from the bit body and having a circumferentially extending outer surface, a leading side and a trailing side;
- a first cone and a second cone rotatably mounted on a cantilevered bearing shaft depending inwardly from the bit legs toward the central axis and each cone having a maximum outside diameter in a shoulder or nose region;
- and,
- a plurality of cutters arranged circumferentially about an outer surface of the cones in the shoulder and/or nose regions, wherein the first cone and the second cone have different maximum outside cone diameters.
Dependencies are inferred from the claim text.