Abstract: A flow stop valve positionable in a downhole tubular, and a method. The flow stop valve is in a closed position when a pressure difference between fluid outside the downhole tubular and inside the downhole tubular at the flow stop valve is between a threshold value, thereby preventing flow through the downhole tubular. The flow stop valve is in an open position when the pressure difference between fluid outside the downhole tubular and inside the downhole tubular at the flow stop valve is above a threshold value, thereby permitting flow through the downhole tubular.

Abstract: A flow stop valve (20) positionable in a downhole tubular (6), and a method, are provided. The flow stop valve (20) is in a closed position when a pressure difference between fluid outside the downhole tubular (6) and inside the downhole tubular (6) at the flow stop valve (20) is below a threshold value, thereby preventing flow through the downhole tubular. The flow stop valve (20) is in an open position when the pressure difference between fluid outside the downhole tubular (6) and inside the downhole tubular (6) at the flow stop valve (20) is above a threshold value, thereby permitting flow through the downhole tubular (6).

Abstract: A flow stop valve positioned in a downhole tubular, particularly a flow stop valve which may be used with a dual density fluid in deep sea drilling or cementing application. The flow stop valve includes a housing and first and second receiving portions attached to first and second ends of the housing. A flow through the valve is selectively permitted between the housing and the first and second receiving portions. A valve element, such as a spindle, is slidably received in the first and second receiving portions. The valve element and housing together form a valve to selectively prevent flow through the flow stop valve. A first end face of the valve element and the first receiving portion define a first chamber and a second end face of the valve element and the second receiving portion define a second chamber.

Abstract: A downhole tubular connector comprising a first body portion and a seal provided on the first body portion, the seal being adapted to selectively provide a seal with a downhole tubular, the downhole tubular connector further comprises a seal protector, wherein one of the seal protector and seal is movable with respect to the other of the seal protector and seal, the seal protector or seal being movable from a first position, in which at least a portion of the seal is protected by a first end of the seal protector, to a second position, in which the portion of the seal is exposed. The seal protector may be disposed so as to be movable from the first position to the second position by contact of the sleeve with the downhole tubular as the downhole tubular connector is brought into engagement with the downhole tubular.

Abstract: A hydraulic connector to provide a fluidic connection between a fluid supply and a downhole tubular, the connector comprising: a body; an engagement assembly comprising an extendable portion selectively extendable from the body, the engagement assembly being configured to extend and retract a seal assembly disposed at a distal end of the extendable portion into and from a proximal end of the downhole tubular; and a valve assembly operable between an open position and a closed position, the valve assembly being configured to: allow a fluid to communicate between the fluid supply and the downhole tubular through the seal assembly when in the open position; and prevent fluid communication between the fluid supply and the downhole tubular when in the closed position.

Abstract: A method to connect a lifting assembly to a bore of a downhole tubular includes providing a communication tool to a distal end of the lifting assembly, the communication tool comprising a body assembly, an engagement assembly, a valve assembly and a seal assembly, sealingly engaging a first portion of the seal assembly in the bore of the downhole tubular, selectively permitting fluid to flow between the lifting assembly and the downhole tubular with the valve assembly, and disengaging the first portion of the seal assembly from the bore of the downhole tubular.

Abstract: A tool to direct a fluids from a lifting assembly and a bore of a downhole tubular includes an engagement assembly configured to selectively extend and retract a seal assembly disposed at a distal end of the tool into and from a proximal end of the downhole tubular and a valve assembly operable between an open position and a closed position, wherein the valve assembly is configured to allow fluids from the lifting assembly to enter the downhole tubular through the seal assembly when in the closed position and wherein the valve assembly is configured to allow fluids from the downhole tubular to be diverted from the lifting assembly when in the open position.

Abstract: A hydraulic connector to provide a fluid tight connection between a fluid supply and a downhole tubular includes an engagement assembly configured to extend and retract a seal assembly disposed at a distal end of the hydraulic connector into and from a proximal end of the downhole tubular, and a valve assembly operable between an open position and a closed position, wherein the valve assembly is configured to allow the fluids to communicate between the fluid supply and the downhole tubular through the seal assembly when in the open position, and wherein the valve assembly is configured to prevent fluid communication between the fluid supply and the downhole tubular when closed position.

Abstract: A connector (10) which provides a fluid tight connection between a fluid supply and a drill-string (4), the connector (10) comprising a piston-rod (20) and a cylinder (15), the piston-rod (20) having a seal at or towards its free end which is adapted to sealingly engage the drill-string (4) when the piston-rod (20) is at least partially extended from the cylinder (15).

Abstract: A hydraulic connector to provide a fluid tight connection between a fluid supply and a downhole tubular includes an engagement assembly configured to extend and retract a seal assembly disposed at a distal end of the hydraulic connector into and from a proximal end of the downhole tubular, and a valve assembly operable between an open position and a closed position, wherein the valve assembly is configured to allow the fluids to communicate between the fluid supply and the downhole tubular through the seal assembly when in the open position, and wherein the valve assembly is configured to prevent fluid communication between the fluid supply and the downhole tubular when closed position.

Abstract: A method to connect a lifting assembly to a bore of a downhole tubular includes providing a communication tool to a distal end of the lifting assembly, the communication tool comprising a body assembly, an engagement assembly, a valve assembly and a seal assembly, sealingly engaging a first portion of the seal assembly in the bore of the downhole tubular, selectively permitting fluid to flow between the lifting assembly and the downhole tubular with the valve assembly, and disengaging the first portion of the seal assembly from the bore of the downhole tubular.

Abstract: A tool to direct a fluids from a lifting assembly and a bore of a downhole tubular includes an engagement assembly configured to selectively extend and retract a seal assembly disposed at a distal end of the tool into and from a proximal end of the downhole tubular and a valve assembly operable between an open position and a closed position, wherein the valve assembly is configured to allow fluids from the lifting assembly to enter the downhole tubular through the seal assembly when in the closed position and wherein the valve assembly is configured to allow fluids from the downhole tubular to be diverted from the lifting assembly when in the open position.

Abstract: A hydraulic connector to direct fluids between a lifting assembly and a bore of a downhole tubular includes an engagement assembly configured to selectively extend and retract a seal assembly disposed at a distal end of the hydraulic connector into and from a proximal end of the downhole tubular and a valve assembly operable between an open position and a closed position, wherein the valve assembly is configured to allow the fluids to communicate between the lifting assembly and the downhole tubular through the seal assembly when in the open position, and wherein the valve assembly is configured to prevent fluid communication between the lifting assembly and the downhole tubular when closed position, and a one-way valve to allow fluid communication from the downhole tubular to the lifting assembly.

Abstract: A downhole drilling tool 136 comprises a drillstring 138, a drilling head 140, and a freewheel 144 for transferring drive from the drillstring to the drilling head. The freewheel 144 is positioned between the drillstring 138 and the drilling head 140.

Abstract: A downhole tool comprises a joint, and a resilient member 65 which extends through the joint and provides a restoring force which tends to strengthen the joint. The joint may comprise a flex coupling 61 which allows limited articulation of the joint. First and second drill string sections 63, 64 may be interconnected by the joint, the resilient member 65 being fixed to interior surfaces of the first and second drill string sections 63, 64. A downhole tool may also comprise primary and secondary sleeves 46 that are supported relative to the mandrel 10 of the drill string. Rotational drive may be transferred from one of the sleeves to the other.

Abstract: A drill string tool such as a drill string stabilizer (1) comprises a circumferentially continuous bearing sleeve (6) having an outside diameter which is equal to or greater than the outside diameter of a radially outermost part of the drill string tool.

Abstract: A casing scraper for cleaning the internal wall of a tube 26 such as a well casing has at least three, rigidly connected, axially and angularly spaced scraper bodies 12, 14, 16 each with a scraping surface 13, 15, 17. The radial dimension of the scraper at each scraping surface is slightly greater than the internal radius of the tube which it will scrape. When the scraper is fully inserted in the tube bore, the scraping surfaces are deflected inwardly and the axial connection 20, 22 between the bodies is accordingly elastically deformed. Th energy stored through this elastic deformation produces a radially outwardly acting force which presses the scraping surfaces 13, 15, 17 against the wall of the tube 26. The eccentric arrangement of the scraping surfaces, and the axial spacing between the surfaces causes the parts of the scraper connecting the scraping surfaces to be placed in bending when the scraper is in place within the tube.

Abstract: Within a longitudinally-extending main housing having a longitudinally-extending duct, an indexing mechanism comprises a mandrel within the duct and capable of longitudinal movement relative to the main housing; a cam sleeve rotatable with respect to the mandrel but constrained in terms of longitudinal movement with respect to the mandrel, the cam sleeve having an external surface provided with a groove in the form of a closed loop; a cam follower resiliently urged into the groove of the cam sleeve; a main spring tending to urge the mandrel in a first direction along the duct; and a fluid abutment face, on which, in use, fluid under pressure can act to tend to urge the mandrel in a second direction opposite to the first direction; the groove having ramps and associated steps thereby restricting relative movement of the cam follower with respect to the groove, to one direction progressively around the closed loop; the groove having a plurality of rest positions at which the cam follower can rest, depending on