Abstract: A drill bit for drilling a bore, the drill bit comprising: an outer housing; a primary cutting structure defining a cutting plane of a first diameter; a flow path arranged to let drilling fluid flow through the drill bit; and a deployable blade assembly at least partially located within the outer housing, the deployable blade assembly comprising a cutting structure and being arranged to be axially movable from a first position, in which the deployable cutting structure is recessed with respect to the primary cutting structure, towards the cutting plane, to a second position; wherein when the deployable blade assembly is in the second position, the deployable cutting structure defines a cutting diameter which is less than or equal to the first diameter.

Abstract: A drill bit for drilling a bore, the drill bit comprising: an outer housing; a primary cutting structure defining a cutting plane of a first diameter; a flow path arranged to let drilling fluid flow through the drill bit; and a deployable blade assembly at least partially located within the outer housing, the deployable blade assembly comprising a cutting structure and being arranged to be axially movable from a first position, in which the deployable cutting structure is recessed with respect to the primary cutting structure, towards the cutting plane, to a second position; wherein when the deployable blade assembly is in the second position, the deployable cutting structure defines a cutting diameter which is less than or equal to the first diameter.

Abstract: A downhole motor (107) which comprises a stator housing (108), a rotor assembly (106) rotatable relative to said stator housing, and an arrangement for enabling, in use, a drill bit connected to the rotor assembly of said downhole motor to be rotated by rotating a drill string connected to said stator housing, wherein said arrangement comprises a unidirectional clutch (117) disposed between said rotor assembly and said stator housing and having at least one pawl which can be displaced between an inoperative position adjacent said stator housing and an operative position in which rotation of said stator housing by said drill string in one sense is transmitted to said rotor assembly via said at least one pawl, means biasing said at least one pawl towards said operative position, means retaining said at least one pawl in its inoperative position, and means which, when sufficient pulling force is applied to said drill string, will cause said means retaining said at least one pawl to release said at least one pawl

Abstract: A drilling assembly assembly includes a hammer motor, a shaft, a driver, and a hammer (218). The shaft is operatively connectable to the hammer motor and rotated thereby. The driver is operatively connectable to the shaft, and includes a cam (such as guide channel 232) rotatable with the shaft and a fixed guide (such as guide pins 230) having a guide surface thereon. The cam is engageable with the guide surface and axially movable thereabout during rotation thereof. The hammer is operatively connectable to the driver and axially movable therewith, axially movable within the housing (215) independently from axial movement of the housing, and engageable with the bit to impart an impact thereto whereby the bit is hammered.

Abstract: A downhole actuating apparatus for actuating downhole. The apparatus is actuatable at the downhole location at, upon or during one or more particular cycle/s selectable from a sequence of cycles according to a predetermined selection. The downhole actuation comprises the release of at least one flowable object from the downhole location. The apparatus releases the at least one flowable object from the downhole location at, upon or during the particular cycle selectable from the sequence of cycles.

Abstract: A downhole tool (10) comprising rotatable inner and outer sleeves (62, 63). The sleeves (62, 63) comprise coupling portions for transmitting a torque between the sleeves (62, 63). The tool is reconfigurable between a first configuration whereby the coupling portions are axially misaligned to prevent transmission of torque between the inner and outer sleeves (62, 63), and a second configuration whereby the coupling portions are axially aligned to permit a transmission of torque between the sleeves (62, 63). At least one of the coupling portions is configured to prevent the transmission of torque above a predetermined torque threshold.

Abstract: A downhole motor (107) which comprises a stator housing (108), a rotor assembly (106) rotatable relative to said stator housing, and an arrangement for enabling, in use, a drill bit connected to the rotor assembly of said downhole motor to be rotated by rotating a drill string connected to said stator housing, wherein said arrangement comprises a unidirectional clutch (117) disposed between said rotor assembly and said stator housing and having at least one pawl which can be displaced between an inoperative position adjacent said stator housing and an operative position in which rotation of said stator housing by said drill string in one sense is transmitted to said rotor assembly via said at least one pawl, means biasing said at least one pawl towards said operative position, means retaining said at least one pawl in its inoperative position, and means which, when sufficient pulling force is applied to said drill string, will cause said means retaining said at least one pawl to release said at least one pawl

Abstract: A downhole actuating apparatus for actuating downhole. The apparatus is actuatable at the downhole location at, upon or during one or more particular cycle/s selectable from a sequence of cycles according to a predetermined selection. The downhole actuation comprises the release of at least one flowable object from the downhole location. The apparatus releases the at least one flowable object from the downhole location at, upon or during the particular cycle selectable from the sequence of cycles.

Abstract: A drilling assembly assembly includes a hammer motor, a shaft, a driver, and a hammer (218). The shaft is operatively connectable to the hammer motor and rotated thereby. The driver is operatively connectable to the shaft, and includes a cam (such as guide channel 232) rotatable with the shaft and a fixed guide (such as guide pins 230) having a guide surface thereon. The cam is engageable with the guide surface and axially movable thereabout during rotation thereof. The hammer is operatively connectable to the driver and axially movable therewith, axially movable within the housing (215) independently from axial movement of the housing, and engageable with the bit to impart an impact thereto whereby the bit is hammered.

Abstract: A downhole tool (10) comprising rotatable inner and outer sleeves (62, 63). The sleeves (62, 63) comprise coupling portions for transmitting a torque between the sleeves (62, 63). The tool is reconfigurable between a first configuration whereby the coupling portions are axially misaligned to prevent transmission of torque between the inner and outer sleeves (62, 63), and a second configuration whereby the coupling portions are axially aligned to permit a transmission of torque between the sleeves (62, 63). At least one of the coupling portions is configured to prevent the transmission of torque above a predetermined torque threshold.

Abstract: A drilling assembly, drilling system and method is provided. The drilling system includes a drilling rig with a drill string deployable therefrom and drivable thereby. The drill string has a bottom hole assembly with a drill bit at a lower end thereof advanceable into a subterranean formation to form a wellbore. The drilling assembly includes at least one mandrel operatively connectable to the drill string, at least one sleeve positionable about the mandrel (the sleeve having an offset stabilizer on an outer surface thereof selectively positionable in contact with a wall of the wellbore), and an orienter with a receptacle on an interior of the sleeve and a socket on an exterior of the mandrel. The socket is interlockingly engageable with the receptacle whereby the sleeve is orientable about the drill string. The one mandrel and the sleeve have a mass offset from the drill string whereby rotation of the drill string is affected during drilling.

Abstract: A rotary steerable tool is provided for use with a drilling apparatus. The rotary steerable tool includes at least a first portion that includes an outer housing, a rotary shaft extending through the outer housing, a drive clutch coupled to the rotary shaft, and a sensor coupled to the rotary shaft. The drive clutch is movable between an engaged configuration and a disengaged configuration. The sensor is configured to identify whether the drive clutch is in at least one of the engaged configuration and the disengaged configuration.

Abstract: A rotary steerable tool is provided for use with a drilling apparatus. The rotary steerable tool includes at least a first portion that includes an outer housing, a rotary shaft extending through the outer housing, a drive clutch coupled to the rotary shaft, and a sensor coupled to the rotary shaft. The drive clutch is movable between an engaged configuration and a disengaged configuration. The sensor is configured to identify whether the drive clutch is in at least one of the engaged configuration and the disengaged configuration.

Abstract: A rotary steerable tool (2) for use in a downhole drilling apparatus for adjusting the direction of drilling is disclosed. The tool comprises a tubular outer housing (20) and a row of steering pushers (24) slidably mounted to the housing for movement between an extended position, in which the steering pusher engages a wall of a borehole formed by the drilling apparatus, and a withdrawn position, in which the steering pushers do not engage the wall of the borehole. A tubular sleeve (4) is mounted inside the housing (20) to transmit rotary drive to a drilling bit. A pressure chamber (22) defined between the sleeve (4) and the housing (20) communicates with the steering pushers (24) to move the steering pushers (24) to the extended position.

Abstract: A direction adjustment tool for a downhole drilling apparatus is disclosed. The tool has a tubular housing adapted to be incorporated into a downhole drilling apparatus, and steering blades mounted to the housing. A drive shaft transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber. A pendulum member is pivotably mounted to extend in a vertical orientation when the shaft is not rotating relative to the housing, and pistons prevent movement of at least one steering blade to the extended position thereof as a result of the angle between a longitudinal axis of the shaft and the longitudinal axis of the pendulum member exceeding a predetermined amount.

Abstract: A downhole swivel joint assembly comprising an upper component and a lower component. The components may assume either of two stable positions relative to each other, namely an unactivated configuration in which the components are rotationally fast with each other by virtue of the inter-engagement of splines of the lower component with splines of the upper component and an activated configuration in which the respective splines are disengaged so that the upper and lower components can rotate relative to each other. In the activated configuration the upper component is supported relative to the lower component on a ball bearing pack. Movement of the components between the activated and unactivated configurations is controlled by a resiliently deformable latch member which is C-shaped in transverse cross-section.

Abstract: A direction adjustment tool 2 for a downhole drilling apparatus is disclosed. The tool has a tubular housing 8 adapted to be incorporated into a downhole drilling apparatus, and steering blades 10 mounted to the housing. A drive shaft 16 transmits drive to a drill bit of a drilling apparatus, wherein the shaft defines a passage for transmitting drilling fluid to the drill bit. A first pressure chamber 32 is defined between the housing and the shaft and communicates with the passage, wherein the steering blades are moved from retracted positions to extended positions thereof as a result of increase of fluid pressure the first pressure chamber.

Abstract: A rotary steerable tool for use in a downhole drilling apparatus for adjusting the direction of drilling is disclosed. The tool comprises a tubular outer housing and a row of steering pushers slidably mounted to the housing for movement between an extended position, in which the steering pusher engages a wall of a borehole formed by the drilling apparatus, and a withdrawn position, in which the steering pushers do not engage the wall of the borehole. A tubular sleeve is mounted inside the housing to transmit rotary drive to a drilling bit. A pressure chamber defined between the sleeve and the housing communicates with the steering pushers to move the steering pushers to the extended position.

Abstract: A downhole releasable swivel joint comprises a mandrel and a housing. A resilently deformable retaining device maintains the components in the illustrated first relative axial position until downward movement of the housing is stopped and a sufficient load is applied to the mandrel to overcome the retaining force of the retaining device whereupon the mandrel is able to move downwardly relative to the housing to adopt a second relative axial position. Apertures are provided in the wall of the mandrel and apertures are provided in the wall of the housing. When the mandrel is in the illustrated first relative axial position the apertures and are isolated from each other by a seal. When the mandrel is in the second relative axial position the apertures communicate with each other to permit flow from the interior of the mandrel to the exterior of the housing.

Abstract: The invention relates to apparatus for use in wellbores and particularly, but not exclusively, to circulating subs used during downhole drilling operations. The apparatus includes a control groove and a pin received within the control groove for determining whether or not a longitudinal movement of a piston in a given direction relative to the apparatus body will move the apparatus between open and closed configurations. The apparatus further includes a control member located between and movable relative to the body and the piston. The control groove is defined in one of the piston and control member, and the pin is provided on the other of the piston and control member. Means are also provided for constraining movement of the piston relative to the body to longitudinal movement only. The invention thus provides an apparatus which has improved reliability in moving between open and closed configurations.