A tool for use in a wellbore includes a tubular body having a bore therethrough, an opening through a wall thereof, and a connector at each longitudinal end thereof; and an arm. The arm is pivotally connected to a first piston and rotationally coupled to the body, is disposed in the opening in a retracted position, and is movable to an extended position where an outer surface of the arm extends outward past an outer surface of the body. The first piston is disposed in the body bore, has a bore therethrough, and is operable to move the arm from the retracted position to the extended position in response to fluid pressure in the piston bore exceeding fluid pressure in the opening. The tool further includes a lock operable to retain the first piston in the retracted position; and a second piston operably coupled to the lock.

A drilling bottom hole assembly for loss circulation mitigation includes a drill bit configured to drill a wellbore in a formation. The drill bit is attached to a drill string. The wellbore includes a high-loss circulation zone into which drilling fluid is lost during drilling the wellbore. An under reamer is attached to the drill string upstring of the drill bit. The under reamer is downhole of the high-loss circulation zone. The under reamer, in response to actuation, is configured to widen a diameter of the high-loss circulation zone. An expansion assembly is connected to the under reamer. The expansion assembly surrounds the drill string upstring of the under reamer. The expansion assembly is configured to cover the high-loss circulation zone after the diameter of the high-loss circulation zone is widened by the under reamer.

A drilling bottom hole assembly for loss circulation mitigation includes a drill bit configured to drill a wellbore in a formation. The drill bit is attached to a drill string. The wellbore includes a high-loss circulation zone into which drilling fluid is lost during drilling the wellbore. An under reamer is attached to the drill string upstring of the drill bit. The under reamer is downhole of the high-loss circulation zone. The under reamer, in response to actuation, is configured to widen a diameter of the high-loss circulation zone. An expansion assembly is connected to the under reamer. The expansion assembly surrounds the drill string upstring of the under reamer. The expansion assembly is configured to cover the high-loss circulation zone after the diameter of the high-loss circulation zone is widened by the under reamer.

A flow rate control system includes a housing and a valve assembly slidingly disposed within a housing inner bore. The housing includes bypass openings. The valve assembly includes a valve and an orifice disposed in a valve inner bore. The valve includes a plurality of valve bypass bores extending axially through a valve collar. The valve assembly slides between closed and fully open positions. A spring biases the valve assembly toward the closed position in which the valve closes the housing bypass openings. In the open position, a bypass fluid path is formed including the valve bypass bores and the housing bypass openings. The valve assembly is flow rate controlled in the closed position and pressure controlled in the open position. The valve assembly may slide within a sleeve assembly including sleeve bypass openings, which connect the valve bypass bores and housing bypass openings in the bypass fluid path.

Tools and methods are described for removing a packer beyond a restriction in a casing of a wellbore. A packer milling tool includes: a milling body with an outer diameter; milling blocks positioned at intervals around a circumference of the milling body, each milling block pivotably attached to the milling body and pivotable between a running position and a milling position; and a wash pipe extending from a downhole end of the milling body. The milling blocks have a rotational circumference with a rotational diameter that is less than the outer diameter of the milling body when in the running position and the rotational diameter is more than the outer diameter of the milling body and less than the inner diameter of the casing when in the milling position.

Tools and methods are described for removing a packer beyond a restriction in a casing of a wellbore. A packer milling tool includes: a milling body with an outer diameter; milling blocks positioned at intervals around a circumference of the milling body, each milling block pivotably attached to the milling body and pivotable between a running position and a milling position; and a wash pipe extending from a downhole end of the milling body. The milling blocks have a rotational circumference with a rotational diameter that is less than the outer diameter of the milling body when in the running position and the rotational diameter is more than the outer diameter of the milling body and less than the inner diameter of the casing when in the milling position.

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 mill for use in a wellbore includes a tubular housing having a bore therethrough, a plurality of pockets formed in a wall thereof, and a blade disposed in each pocket. Each blade includes a body having a first side opposite a second side, wherein the first side faces in a direction of rotation of the mill. The blade also includes a blade portion disposed on the first side of the body, wherein the blade portion has a first cutting face stepped relative to a second cutting face. Each blade is movable between a retracted position and an extended position, wherein a portion of the first side and the second side protrude from the housing in the extended position.

A method includes extending a wellbore using a drill bit that forms a portion of a bottom hole assembly; enlarging a diameter of the wellbore using a reamer of the assembly; and laterally offsetting either a rotary steerable tool or a mud motor of the assembly in the enlarged diameter wellbore. A bend angle is defined between a central axis of either the rotary steerable tool or the mud motor creates and a central axis of the drill bit. Enlarging the diameter of the wellbore using the reamer while steering the assembly decreases the dogleg. Enlarging the diameter of the wellbore using the reamer while rotational drilling a straight section of the wellbore reduces stresses on the assembly and reduces wellbore tortuosity.