Abstract: 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.

Abstract: A packer apparatus for providing an annular seal in a wellbore is described. The packer apparatus has a body defining a first bore to enable working fluid such as hydraulic fracturing fluid containing proppant to flow through the packer apparatus. A first channel is formed in the body and is arranged to hold hydraulic fluid. A first floating piston is disposed in the first channel, the first floating piston being in fluid communication with the first bore via a passage. A plurality of pistons is arranged to move the activation member relative to the body to deform an elastomeric packer element outwardly relative to the body.

Abstract: A downhole expandable drive reamer apparatus is described. The apparatus comprises a body defining a longitudinal axis X-X. At least one roller is disposed on the body and is moveable relative to the body between an inwardly retracted condition and an outwardly deployed condition. A thread or other protrusion is formed on at least one roller and is arranged to engage a surface of a well bore to drive the apparatus to along the well bore when the roller is in the outwardly deployed condition. The rotational axis R-R of the roller is non-parallel to the longitudinal axis X-X of the body.

Abstract: 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.

Abstract: A downhole expandable roller bearing apparatus is described. The apparatus comprises a plurality of roller assemblies comprising at least one roller rotatably mounted between pistons. A retaining member such as a spline bar is removably mounted in a keyway formed in the body. Each piston comprises an aperture through which the spline bar projects in both the inwardly retracted and outwardly deployed positions of the pistons.

Abstract: A perforating tool usable in a well casing to perforate the well casing is described. Perforating tool includes an activation member disposed in body wherein the activation member is moveable relative to the body to move at least one working member between and inwardly retracted condition an outwardly deployed condition relative to the body. 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.

Abstract: An expandable downhole tool apparatus includes a body adapted to be incorporated into a drill string and at least one working member moveable relative to the body between an inward deactivated position and an outwardly deployed activated position in order to engage the wall of a borehole. An activation device moves at least one working member between the inward deactivated position and outwardly deployed activated position. At least one passage is formed through the body and extends from a location on the body adjacent at least one working member to a location remote from the respective working member to enable debris accumulating underneath the respective working member to move along the passage and exit the body.

Abstract: A drillstring valve has an inlet mountable to a drillstring, an outlet and a passageway extending between the inlet and the outlet in a predetermined operating condition. In accordance with an embodiment, the drillstring valve comprises a stop element adapted for receiving a valve element wherein the stop element comprises at least one protrusion extending into a passageway portion of the passageway to thereby retain the valve element. According to an embodiment, the at least one protrusion is spaced from an inlet edge having a continuously reduced diameter in downstream direction. According to a further embodiment, the stop element comprises two or more protrusions which are spaced in circumferential direction of the passageway portion into which the at least two protrusions extend.

Abstract: A perforating tool usable in a well casing to perforate the well casing is described. Perforating tool comprises an activation member disposed in body wherein the activation member is moveable relative to the body to move at least one working member between and inwardly retracted condition an outwardly deployed condition relative to the body. A plurality of pistons is arranged to move the activation member relative to the body, each said 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.

Abstract: A downhole circulation apparatus comprises at least one tubular body portion defining a first through-flow passage through which drilling fluid can pass along the drill string. A first sleeve is slidably mounted in the tubular body portion and is biased into a position in which the first port means is closed by a biasing means such as a spring. Second port means is formed through the tubular body portion at a location below the first port means in the drill string. The second port means may comprise a plurality of second nozzles, wherein each of the second nozzles has a diameter greater than the diameter of each of the first nozzles of the first port means. Larger nozzles enable large particle size drilling fluid to be bypassed. A second sleeve is slidably mounted inside the tubular body portion.

Abstract: An expandable downhole tool such as an under-reamer or a stabiliser includes a mandrel mounted for linear slidable movement relative to a main body. The mandrel, together with one or more travel blocks, cause movement of a working component in an axial direction. One or more outwardly extending guide paths slidably interact with the working component to cause the working component to move between a withdrawn inoperative position and an outwardly deployed operative position. Upon increase of hydraulic pressure from below the tool, the mandrel is urged against a spring biasing the deactivated position to move axially and cause the working component to take its operative position. Upon decrease of hydraulic pressure, the spring moves the mandrel axially to cause the working component to take its withdrawn inoperative position.

Abstract: A downhole expandable roller bearing apparatus is described. The apparatus comprises a plurality of roller assemblies comprising at least one roller rotatably mounted between pistons. A retaining member such as a spline bar is removably mounted in a keyway formed in the body. Each piston comprises an aperture through which the spline bar projects in both the inwardly retracted and outwardly deployed positions of the pistons.

Abstract: An expandable downhole tool apparatus is disclosed. The apparatus comprises a body adapted to be incorporated into a drill string and at least one working member moveable relative to the body between an inward deactivated position and an outwardly deployed activated position in order to engage the wall of a borehole. Activation means adapted to move at least one said working member between the inward deactivated position and outwardly deployed activated position is provided. At least one passage is formed through the body and extends from a location on the body adjacent at least one working member to a location remote from the respective working member to enable debris accumulating underneath the respective working member to move along the passage and exit the body.

Abstract: An activating device is mounted in a drill string to control the activation and deactivation of an enlargement tool used for enlarging a bore hole. In order to assemble the activating device, pistons are mounted in passages and spline bars, in which plates are screwed, are then slid along T-slots of the body, through apertures of the pistons. In order to deploy the pistons and cutters, pressurized drilling fluid is applied to the inner faces of the pistons. When a pre-determined pressure level is reached, screws break and the pistons move from the inward position to the outwardly deployed position.

Abstract: An expandable downhole tool such as an under-reamer or a stabiliser includes a mandrel mounted for linear slidable movement relative to a main body. The mandrel, together with one or more travel blocks, cause movement of a working component in an axial direction. One or more outwardly extending guide paths slidably interact with the working component to cause the working component to move between a withdrawn inoperative position and an outwardly deployed operative position. Upon increase of hydraulic pressure from below the tool, the mandrel is urged against a spring biasing the deactivated position to move axially and cause the working component to take its operative position. Upon decrease of hydraulic pressure, the spring moves the mandrel axially to cause the working component to take its withdrawn inoperative position.

Abstract: An expandable downhole tool such as an under-reamer or a stabiliser includes a mandrel mounted for linear slidable movement relative to a main body. The mandrel, together with one or more travel blocks, cause movement of a working component in an axial direction. One or more outwardly extending guide paths slidably interact with the working component to cause the working component to move between a withdrawn inoperative position and an outwardly deployed operative position. Upon increase of hydraulic pressure from below the tool, the mandrel is urged against a spring biasing the deactivated position to move axially and cause the working component to take its operative position. Upon decrease of hydraulic pressure, the spring moves the mandrel axially to cause the working component to take its withdrawn inoperative position.

Abstract: An activating mechanism for controlling the operation of a downhole tool in a drill string and which is intended to be housed in a portion of the drill string upstream of the downhole tool, in which: the activating mechanism has a first mode in which it allows through-flow of drilling fluid to the downhole tool and a second mode in which through-flow of fluid is blocked; and the activating mechanism has a number of through-flow ports permitting through-flow of drilling fluid in said first mode of the mechanism and which are capable of being blocked by launching a number of flow blocking activator balls down the drill string and which each are of such size and shape that they can block access to said through-flow ports in order to activate the mechanism to the second mode and thereby adjust the downhole tool from one mode of operation to another.

Abstract: A ball-activated mechanism adapted to be incorporated in a drillstring and to control the activation, and de-activation of a downhole tool. The mechanism includes a ball seat that receives surface launched activation balls and moves to activate or deactivate the downhole tool, an indexable latching device, and a linearly displaceable actuator co-operable with the indexable latching device, the actuator allowing pressure fluid communication to activate the tool when the actuator is in its activating position. Upon launch of a first activation ball, the ball seat moves so that the latching device carries out indexing movement to a latched position and moves the actuator moves to its activating position so that the downhole tool can be activated. Upon launch of a second activation ball, the latching device undergoes return movement and returns the ball seat to its first position and the actuator moves to deactivate the downhole tool.

Abstract: An activating device is mounted in a drill string to control the activation and deactivation of an enlargement tool used for enlarging a bore hole. In order to assemble the activating device, pistons are mounted in passages and spline bars, in which plates are screwed, are then slid along T-slots of the body, through apertures of the pistons. In order to deploy the pistons and cutters, pressurized drilling fluid is applied to the inner faces of the pistons. When a pre-determined pressure level is reached, screws break and the pistons move from the inward position to the outwardly deployed position.

Abstract: An activating mechanism for controlling the operation of a downhole tool in a drill string and which is intended to be housed in a portion of the drill string upstream of the downhole tool, in which: the activating mechanism has a first mode in which it allows through-flow of drilling fluid to the downhole tool and a second mode in which through-flow of fluid is blocked; and the activating mechanism has a number of through-flow ports permitting through-flow of drilling fluid in said first mode of the mechanism and which are capable of being blocked by launching a number of flow blocking activator balls down the drill string and which each are of such size and shape that they can block access to said through-flow ports in order to activate the mechanism to the second mode and thereby adjust the downhole tool from one mode of operation to another.