Patent ID: 8485280
Filing Date: 2013-07-16
Classification: E21B

Abstract:
1. A core barrel head assembly configured to be removably received within a drill string, the drill string having a longitudinal axis and an inner surface defining an annular groove, the core barrel head assembly comprising: a sleeve having a plurality of openings extending there through; a plurality of wedge members positioned at least partially within respective openings of the plurality of openings, the plurality of wedge members being unattached to the core barrel head assembly; and a driving member defining a plurality of driving surfaces, the driving member being positioned at least partially within the sleeve, the plurality of driving surfaces cooperating to define a circumferentially tapered outer surface of the driving member such that, at a selected axial position relative to the longitudinal axis of the drill string, the distance between the inner surface of the drill string and the outer surface of the driving member varies circumferentially about the outer surface of the driving member, the driving member including at least one first groove extending therein, the at least one first groove being configured to receive and maintain the plurality of wedge members in a retracted position within the sleeve, wherein the at least one first groove of the driving member is configured to maintain the plurality of wedge members in the retracted position such that the plurality of wedge members do not drag along the inner surface of the drill string during tripping of the core barrel head assembly, wherein the plurality of wedge members are adapted to axially lock the core barrel head assembly relative to the drill string by extending radially outward of the sleeve into the annular groove in the inner surface of the drill string, and wherein, upon rotation of the drill string, the plurality of driving surfaces are configured to wedge the plurality of wedge members between the inner surface of the drill string and the driving member such that the core barrel head assembly is rotationally locked relative to the drill string.