2-Stage underreamer
AssigneeSmith International, Inc.
InventorsBruce McGarian, Richard Alvin Armell
Life of this patent
Estimating the term…
Abstract
A 2-stage underreamer for use in a subterranean wellbore includes a unitary body having upper and lower blades mounted in slots formed perpendicular to each other in the body. Separate upper and lower piston assemblies are provided for driving the blades respectively from a storage configuration in which they are located substantially completely within the slots to a use position. The blades each include a steel arm having mounted thereon a base of tungsten nickel cobalt matrix in which diamond and/or tungsten carbide inserts are provided. A signal is given to the surface that the blades are in their extended position by changing the mud.
Claims15
A 2-stage underreamer comprising an upper pair of reaming blades arranged in a slot or pocket in a body and a lower pair of reaming blades arranged in a slot or pocket in the body, the body being unitary and the blades being hingedly mounted on the body and moveable by power means from a retracted storage position to an extended use position wherein at least one pair of blades is moveable from the retracted storage position to the extended use position by power means comprising a hydraulically actuated piston incorporating a first piston portion having a circular face on which hydraulic fluid acts to generate a force and a second piston portion which is annular and upon which hydraulic fluid acts to create a force reinforcing that produced by the hydraulic fluid acting on the first piston portion.
A reaming tool for use in a subterranean wellbore, the tool comprising a body and at least one blade moveable relative to the body between a storage position in which the or each blade is located when the tool is run into the well and a use position in which the or each blade extends from the body, the or each blade comprising an arm of steel and a multiplicity of wear resistant assemblies secured to the arm, wherein the wear resistant assemblies are provided on a gauge face and on an adjacent cutting face of the or each blade, the multiplicity of wear resistant assemblies being secured to the arm as an integral unitary member by means of a single base component in which the multiplicity of wear resistant assemblies is embedded, the base component being secured to the arm by welding or brazing.
Dependencies are inferred from the claim text.