A method to provide support within a wellbore includes underreaming a section of the wellbore at a depth spanning a layer of an unstable formation. The method also includes deploying a bistable structure within the wellbore at the depth of the layer of the unstable formation. Additionally, the method includes actuating an expandable packer within the bistable structure to expand the bistable structure in a radially outward direction from a longitudinal axis of the bistable structure. The bistable structure is in contact with walls of the underreamed section of the wellbore upon expanding in the radially outward direction.

A method to provide support within a wellbore includes underreaming a section of the wellbore at a depth spanning a layer of an unstable formation. The method also includes deploying a bistable structure within the wellbore at the depth of the layer of the unstable formation. Additionally, the method includes actuating an expandable packer within the bistable structure to expand the bistable structure in a radially outward direction from a longitudinal axis of the bistable structure. The bistable structure is in contact with walls of the underreamed section of the wellbore upon expanding in the radially outward direction.

A packer apparatus usable in a well casing to provide an annular seal in the well casing. The packer apparatus includes an activation member mounted to the body wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in the well casing. A plurality of pistons is arranged to move the activation member relative to the body, each piston being disposed in a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body.

A packer apparatus usable in a downhole well casing or an open borehole to provide an annular seal in the well casing or borehole. The packer apparatus includes an activation member disposed in body wherein the activation member is moveable relative to the body to deform an elastomeric packer element outwardly relative to the body to form an annular seal in a well casing in use. A plurality of pistons is arranged to move the activation member relative to the body, each piston being disposed in a respective pressure chamber arranged to be filled with fluid in response to an increase in fluid pressure in the body.

A method of manufacturing an earth boring tool body including the following steps: providing a mold, the mold comprising a mold cavity defining an interior surface corresponding to an exterior shape of a tool body and a plurality of blades. Forming at least one barrier sleeve insert and disposing it adjacent the interior surface defining the mold cavity; disposing a first powder in the gap between the insert and the interior surface, disposing a second powder in the mold cavity; disposing an infiltrant material adjacent the powders; and heating the mold, thereby infiltrating the infiltrant material into the powders to form the tool body. The disclosure also includes a mold for manufacturing an earth boring tool, the mold comprising a mold cavity defining interior surfaces corresponding to an exterior shape of the tool body and the plurality of blades. Barrier sleeve inserts and/or containment sleeve inserts may be disposed adjacent interior surfaces the mold cavity.

A method of manufacturing an earth boring tool body including the following steps: providing a mold, the mold comprising a mold cavity defining an interior surface corresponding to an exterior shape of a tool body and a plurality of blades. Forming at least one barrier sleeve insert and disposing it adjacent the interior surface defining the mold cavity; disposing a first powder in the gap between the insert and the interior surface, disposing a second powder in the mold cavity; disposing an infiltrant material adjacent the powders; and heating the mold, thereby infiltrating the infiltrant material into the powders to form the tool body. The disclosure also includes a mold for manufacturing an earth boring tool, the mold comprising a mold cavity defining interior surfaces corresponding to an exterior shape of the tool body and the plurality of blades. Barrier sleeve inserts and/or containment sleeve inserts may be disposed adjacent interior surfaces the mold cavity.

Bottom hole assemblies with a combined roller-underreamer assembly can include: a body configured to be attached to a drill pipe; an uphole ring attached to the body; a downhole ring attached to the body between the uphole ring and the downhole end of the body; a sliding ring mounted around the body between the uphole ring and the downhole ring; a set tube slidably mounted around the body between the uphole ring and the sliding ring; a reamer assembly with at least one first articulated arm with extending between the uphole ring and the downhole end of the set tube; and a roller assembly with: at least one second articulated arm extending between the uphole end of the set tube and the sliding ring; and a rolling positioned at a joint of each second articulated arm.

A reaming tool includes a tool body having a longitudinal axis and an upper end opposite a lower end and at least one blade extending outwardly from the external surface of the tool body. The blade includes a rolling element defining the gauge of the reaming tool, and a blade surface arranged undergauge of the rolling element and comprising a cutting surface.

A method to provide support within a wellbore includes underreaming a section of the wellbore at a depth spanning a layer of an unstable formation. The method also includes deploying a bistable structure within the wellbore at the depth of the layer of the unstable formation. Additionally, the method includes actuating an expandable packer within the bistable structure to expand the bistable structure in a radially outward direction from a longitudinal axis of the bistable structure. The bistable structure is in contact with walls of the underreamed section of the wellbore upon expanding in the radially outward direction.

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.