Underreamer
AssigneeTransco Manufacturing Australia Pty Ltd
InventorsRoy Estes, George Fyfe
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to an underreamer. In one aspect, the underreamer comprises a body, the body comprising at least one pocket therein, the underreamer further comprising at least one cutter secured with respect to the body, at least one actuating mechanism for moving the cutter between a retracted position in the pocket, and an extended position in which only the cutter projects from the body. In one aspect, the or each actuating mechanism comprises a piston for driving extension of the cutter, and a linkage to a cutter arm with respect to which the cutter is mounted, and a return spring for biasing the cutter to the retracted position.
Claims20
An underreamer comprising a body, the body comprising at least one pocket therein, the underreamer further comprising a plurality of cutters secured with respect to the body, and for each cutter of the plurality of cutters a respective pocket and a respective actuating mechanism comprising a piston which is slidably disposed in a piston bore, a linkage which has a first end mechanically coupled to the piston, an arm at a second end of the linkage opposite to the first end, and an axis pin which directly, mechanically and rotatably couples the arm to the second end of the linkage for moving the cutter between a retracted position within the pocket and an extended position in which only the cutter projects from the body, and wherein a central drilling fluid bore extends through the body and a plurality of channels extend from the central drilling fluid bore to the piston bores to deliver drilling fluid to drive the pistons and thus the cutters to their extended positions.
An underreamer comprising a body, the body comprising at least one pocket therein, the underreamer further comprising a plurality of cutters mounted with respect to the body, and for each of the plurality of cutters a respective pocket and a respective actuating mechanism comprising a piston which is slidably disposed in a piston bore, a linkage which has a first end mechanically coupled to the piston, an arm at a second end of the linkage opposite to the first end, and an axis pin which directly, mechanically and rotatably couples the arm to the second end of the linkage for pivoting the cutter between a retracted position within the pocket and an extended position in which the cutter is oriented to a cut formation, and wherein a central drilling fluid bore extends through the body, and for each cutter of the plurality of cutters a channel extends from the central drilling fluid bore to the piston bores to deliver drilling fluids to drive the piston and thus the cutters to their extended positions.
An underreamer, comprising a body, the body comprising at least one pocket therein, the underreamer further comprising a plurality of cutters secured with respect to the body, and for each cutter of the plurality of cutters a respective pocket and a respective actuating mechanism comprising a piston which is slidably disposed in a piston bore, a linkage which has a first end mechanically coupled to the piston, a third end of an arm at a second end of the linkage opposite to the first end, a fourth end of the arm opposite to the third end, and an axis pin in the second end of the linkage and in the third end of the arm which mechanically and rotatably couples the third end of the arm to the second end of the linkage for moving the cutter between a retracted position within the pocket and an extended position in which only the cutter projects from the body, and wherein a central drilling fluid bore extends through the body and a plurality of channels extend from the central drilling fluid bore to the piston bores to deliver drilling fluid to drive the pistons and thus the cutters to their extended positions.
Dependencies are inferred from the claim text.