Abstract: A tool (1) for cementing an annulus in a subsea oil or gas well, and methods for using the tool are provided. The tool includes a safety module (2) providing fluid communication between an umbilical and a perforation and circulation module (4) mounted below it. The safety module (2) includes a mechanical lock for connection to a well head. The perforation and circulation module includes upper and lower seals (6, 8) for sealing to the inner surface of a casing; an upper perforating device (14) mounted between the seals; a lower perforating device (16) mounted below the lower seal (8); and supply (S) and return (R) fluid flow paths for circulating fluid from the safety module (2). A diversion means (20) is provided in the supply fluid flow path, operable to redirect fluid supplied to the supply fluid flow path to a space defined between the upper and lower seals (6, 8).

Abstract: The present invention provides an aircraft structure comprising a first sub-structure, having a first box cross-section, a second sub-structure, having a second box cross-section, and a joint joining a first end region of the first sub-structure to second end region of the second sub-structure, wherein the joint comprises an overlap region where the end regions of the first and the second sub-structures overlap such that the first sub-structure is inside the second sub-structure. The present invention also provides an aircraft comprising such an aircraft structure and a method of manufacturing an aircraft structure.

Abstract: An apparatus for circulating well fluids in an intervention system is described. The apparatus comprises at least one subsea storage vessel adapted to be located adjacent a subsea intervention system, a first conduit adapted to provide fluid communication between the at least one storage vessel and the intervention system, a second conduit adapted to provide fluid communication between the at least one storage vessel and the intervention system and at least one pump adapted to pump fluid from the at least one storage vessel to the intervention system or from the intervention system to the at least one storage vessel through said first and/or second conduits.

Abstract: The present invention provides an aircraft structure comprising a first sub-structure, having a first box cross-section, a second sub-structure, having a second box cross-section, and a joint joining a first end region of the first sub-structure to second end region of the second sub-structure, wherein the joint comprises an overlap region where the end regions of the first and the second sub-structures overlap such that the first sub-structure is inside the second sub-structure. The present invention also provides an aircraft comprising such an aircraft structure and a method of manufacturing an aircraft structure.

Abstract: A well containment system is described, the system comprises a blow out preventer, the blow out preventer defining a throughbore and including at least one well containment barrier adapted to seal the throughbore, at least one first seal adapted to seal against the lower end of a riser, and at least one second seal adapted to seal against the upper end of a downhole tubular wherein the at least one first seal is located above the at least one well containment barrier and the at least one second seal is located below the at least one well.

Abstract: A subsea winch is described. The subsea winch comprises a housing adapted to be attached to a well intervention system, the housing having an inlet and an outlet and at least one powered sheave arranged between the inlet and the outlet, the or each powered sheave having a surface adapted to form a frictional engagement with a cable passing between the inlet and the outlet via the at least one sheave. In use, a pull force pulling the cable in a downhole direction applied to the cable by a tool string being lowered into the well intervention system is increased by the winch such that the downhole pull force on the cable at the housing inlet is greater than the downhole pull force at the housing outlet.

Abstract: An apparatus for circulating well fluids in an intervention system is described. The apparatus comprises at least one subsea storage vessel adapted to be located adjacent a subsea intervention system, a first conduit adapted to provide fluid communication between the at least one storage vessel and the intervention system, a second conduit adapted to provide fluid communication between the at least one storage vessel and the intervention system and at least one pump adapted to pump fluid from the at least one storage vessel to the intervention system or from the intervention system to the at least one storage vessel through said first and/or second conduits.

Abstract: A well containment system is described, the system comprises a blow out preventer, the blow out preventer defining a throughbore and including at least one well containment barrier adapted to seal the throughbore, at least one first seal adapted to seal against the lower end of a riser, and at least one second seal adapted to seal against the upper end of a downhole tubular wherein the at least one first seal is located above the at least one well containment barrier and the at least one second seal is located below the at least one well.

Abstract: A subsea winch is described. The subsea winch comprises a housing adapted to be attached to a well intervention system, the housing having an inlet and an outlet and at least one powered sheave arranged between the inlet and the outlet, the or each powered sheave having a surface adapted to form a frictional engagement with a cable passing between the inlet and the outlet via the at least one sheave. In use, a pull force pulling the cable in a downhole direction applied to the cable by a tool string being lowered into the well intervention system is increased by the winch such that the downhole pull force on the cable at the housing inlet is greater than the downhole pull force at the housing outlet.

Abstract: A resin mixture for forming a stable closed cell foam contains a phenolic resole, a chain extending agent, and as curing agents, a base, and an ester and/or an aliphatic carbonate. The chain extending agent is especially an epoxy resin and/or a phenolic novalak resin.

Abstract: A resin mixture for forming a stable closed cell foam contains a phenolic resole, a chain extending agent, and as curing agents, a base, and an ester and/or an aliphatic carbonate. The chain extending agent is especially an epoxy resin and/or a phenolic novalak resin.

Abstract: A closed cell phenolic foam is formed from a phenolic resin, a blowing agent such as HCFC141b, a catalyst and less than 2.5% by weight relative to the resin of at least one hydrofluoroether or an azeotrope formulation thereof. 1-methoxy-nonafluorobutane and especially an azeotrope formulation thereof with trans-1,2-dichloroethylene are preferred hydrofluoroethers. The phenolic foam has a stable closed cell content of greater than 90% and a stable thermal conductivity.

Abstract: A closed cell phenolic foam is formed from a phenolic resin, a blowing agent such as HCFC141b, a catalyst and less than 2.5% by weight relative to the resin of at least one hydrofluoroether or an azeotrope formulation thereof 1-methoxy-nonafluorobutane and especially an azeotrope formulation thereof with trans-1,2-dichloroethylene are preferred hydrofluoroethers. The phenolic foam has a stable closed cell content of greater than 90% and a stable thermal conductivity.

Abstract: A Christmas tree (16) is based on a dual bore sub-sea test tree. The Christmas tree consists of a Christmas tree housing (56), which connects to a wellhead (44), a Christmas tree valve block assembly (62) disposed in the housing (56) and a tree cap (84) which connects to the housing (56) and valve block assembly (62). In a preferred embodiment the valve block assembly (62) has a main production bore (70) with two valves (72,74) in series and two auxiliary bores (76,96). One auxiliary bore (96) has a valve (98) for facilitating control of the annulus bore (96) whereas the other annulus bore (76) has no valve and provides a pathway for an electrical submersible cable (66) to a pump. The valves (72,74,98) are actuatable via control from an umbilical (94) and provide the facility to seal the production and annulus access bores to meet statutory requirements. A tubing hanger is not required.

Abstract: A bore selection apparatus (38) is described for facilitating access from a single bore riser to a production bore (34,34a) or annulus bore (36, 36a) without using a wireline-run whipstock. The bore selector apparatus disposed within the bore of a BOP stack (12) and which can be coupled between casing or tubing and a sub-sea test tree. The bore selector apparatus (38) can be actuated from the surface or from an ROV to provide a coupling between the tubing bore (44) and the production bore (34, 34a) or between the tubing bore (44) and the smaller annulus bore (36, 36a).

Abstract: A wellhead cap assembly (10) includes a high security barrier (16) for installation onto a wellhead (12) containing any leakage safely and for permitting the installation of a subsea xmas tree onto the wellhead (12) whilst, simultaneously, providing means for containing full pressure control during rectification of the leak. The barrier (16) is provided by an internal tree cap which allows pressure between the top of the tubing hanger (34) and the underside of the tree cap (16) to be monitored by pressure monitoring means (20) via a port (29) in the assembly (10) and, in addition, in the event the presence of well bore fluids is detected indicating that leakage has occurred, the cap assembly allows intervention in order to rectify the leakage.

Abstract: A single bore riser system is disclosed which is based on a dual bore completion tree. An eccentric offset sub is coupled to the top of the tree and which can be sealed by BOP pipe rams. The completion tree has a main bore and an auxiliary bore with ball valves located in the respective bores. A remotely actuatable annulus plug is located in the bottom of the annulus bore and is moveable between a first position allowing fluid flow through the annulus bore and a second position sealing the annulus bore to provide control of various operations. Embodiments of the invention are described.

Abstract: An improved sub-sea Xmas tree consists of a wellhead connector, a cylindrical structural housing and a tree cap mounted on top of the housing. A dual bore sub-sea completion test tree is disposed in the housing and it has a main production bore with serial ball valves for controlling fluid flow in the production flow path of an annuus bore with a ball valve therein. The ball valves are independently and remotely actuatable by a remotely operated vehicle (ROV) override system to control communication through the Xmas tree and to comply with various regulatory standards. A cross-over valve is provided between the main bore and the annulus bore to allow fluid passage for well kill operations.

Abstract: A lightweight intervention apparatus is described for use with a single bore intervention operation and which is suitable for use with a sub-sea horizontal tree with a tree cap and integral ball valve. The lightweight intervention apparatus is adapted to be coupled to the horizontal tree and that when so coupled the integral ball valve within the tree can be actuated via the intervention apparatus and cycled between an open and a closed position. The annulus line within the horizontal tree is adapted to be coupled through the lightweight intervention apparatus to a separate annulus line such that the annulus line is separate from the main bore to facilitate control of the annulus for certain well functions. A significant advantage of this arrangement is that the internal diameter of the main bore is not reduced in any way by apparatus or equipment for separating the annulus line from the main bore so that full bore diameter may be used.

Abstract: A dual bore riser system is described which includes a conventional monobore riser (12) for production access and an independent coil tubing (14) disposed in parallel with the monobore riser (12) for providing annular access. The monobore riser includes discrete A joints of tubing, casing or drill pipe and the coil tubing riser may be any suitable size but is normally between 23/8" and 27/8" outside diameter. The standard monobore riser (12) and coil tubing riser (14) is fed from a coiled tubing reel (78), which is conventional, via a sheave (80) and straightening rollers into the well with the tubing riser. The coiled tubing is clamped to the tubing riser by clamps (16) at intervals along its length corresponding to a joint every 30 ft. The upper end of the landing spool adaptor (28) receives the tubing (14) and also contains a termination for the coiled tubing which is typically a swage device (32). The 5".times.