Continuous sampling drill bit
AssigneeLongyear TM, Inc.
InventorsChristopher L. Drenth, Andrew Robert Corona
Life of this patent
Estimating the term…
Abstract
A drill bit comprises a first and a second body received within the first body. Each of the first body and second body has a respective crown, each crown having an inner and an outer operative circumference. The outer operative circumference of the second body and the inner operative circumference of the first body can define a first volume that can receive a tubular core sample. The second body can define a break surface that breaks the tubular core sample into core pieces. The drill bit can be employed in a borehole with a reverse circulation system that pumps fluid around an outer surface of the bit, and returning fluid can carry the core pieces out of the borehole.
Claims15
An assembly comprising:
- a drill bit having a central axis, the drill bit comprising:
- a first body comprising a shank defining an inner bore and a crown having a cutting face, wherein the crown of the first body defines an outer operative circumference and an inner operative circumference;
- and
- a second body coupled to the first body and comprising a shank and a crown having a cutting face, wherein the crown of the second body defines an outer operative circumference and is received within the inner operative circumference of the first body, the crown of the second body having an outer diameter,
- wherein the inner operative circumference of the crown of the first body and the outer operative circumference of the crown of the second body cooperate to define a first volume, wherein the first volume is configured to receive a tubular core sample,
- wherein the shank of the second body has an outer diameter and a first frustoconical outer surface, wherein the outer diameter of the shank along the first frustoconical outer surface increases moving along the central axis in a direction away from the cutting face of the first body, wherein along the first frustoconical outer surface, the outer diameter of the shank of the second body is sufficiently greater than the outer diameter of the crown of the second body to break the tubular core sample into core pieces as the tubular core sample advances against the first frustoconical outer surface,
- wherein the first body and the second body cooperate to define a second volume that is in communication with and positioned proximally of the first volume, wherein the first frustoconical outer surface of the shank of the second body defines at least part of the second volume, and
- wherein the first body defines at least one conduit between the second volume and the inner bore of the shank of the first body, wherein the at least one conduit is adapted to enable travel of the core pieces from the second volume to the inner bore of the shank of the first body of the drill bit;
- and
- at least one dual-tube drill rod comprising:
- an outer rod;
- and
- an inner rod positioned within an outer rod,
- wherein the inner rod and outer rod cooperate to define an inner annulus, and
- wherein the inner rod defines an inner return conduit,
- wherein the at least one conduit of the drill bit is in communication with the inner return conduit.
Dependencies are inferred from the claim text.