Abstract: A system for generating energy from a water current flowing in a body of water. For example, the system may have a generator assembly operable to generate energy in response to the flow of the current and an anchor assembly located at the bed of the body of water, where the generator assembly is attached to the anchor assembly, is held between the bed and the surface of the body of water, and is rotatable about a substantially vertical axis with respect to the anchor assembly. For another example, the generator assembly may include a housing that is held in an upstream orientation when in use, and an impellor assembly located within the housing and including a plurality of blades arranged to be contacted by the flow of the water when in use.

Abstract: A system for the generation of energy from the flow of water in a body of water is provided, the system comprising a support assembly extending across at least a portion of the body of water; a generator assembly mounted in the support assembly, the generator assembly comprising a first rotor assembly and a second rotor assembly, each rotor assembly comprising a vertical hub rotatable about a vertical axis and a plurality of vertical blades extending radially from the hub, the first and second rotor assemblies being arranged such that the volume swept by the blades of the first rotor assembly overlaps the volume swept by the blades of the second rotor assembly. The system may be used to generate energy, for example electricity. In addition, the system may be used to control the level of water on the upstream side of the installation, for example in the cases of flooding.

Abstract: A system for generating energy from a current flowing in an ocean is disclosed, the system comprising a generator assembly comprising a generator and operable to generate energy in response to the flow of the current; an anchor assembly at the bed of the ocean; and a retaining means attaching the generator assembly directly to the anchor assembly, the generator assembly being held between the bed of the ocean and the surface of the body of water, and the generator assembly being rotatable about a substantially vertical axis with respect to the anchor assembly. A preferred generator assembly is disclosed, the assembly comprising a housing having a form such that, in use, the housing has an upstream orientation; an impellor assembly located within the housing comprising a plurality of blades arranged to be contacted by the flow of water when in use; and means to be acted upon by the flow of water to hold the housing in the upstream orientation.

Abstract: A system for the generation of energy from the flow of water in a body of water is provided, the system comprising a support assembly extending across at least a portion of the body of water; a generator assembly mounted in the support assembly, the generator assembly comprising a first rotor assembly and a second rotor assembly, each rotor assembly comprising a vertical hub rotatable about a vertical axis and a plurality of vertical blades extending radially from the hub, the first and second rotor assemblies being arranged such that the volume swept by the blades of the first rotor assembly overlaps the volume swept by the blades of the second rotor assembly. The system may be used to generate energy, for example electricity. In addition, the system may be used to control the level of water on the upstream side of the installation, for example in the cases of flooding.

Abstract: An apparatus for controlling the flow of a first fluid stream within a bulk rotating fluid stream is disclosed, the apparatus comprising a fluid flow region having a longitudinal axis, within which a rotating flow of fluid may be established; a flow guide having a convex outer surface disposed centrally within the fluid flow region, the convex outer surface of the flow guide extending parallel to the longitudinal axis of the fluid flow region, the convex surface being shaped to induce a spiral coanda effect in the flow of the first fluid stream over the flow guide.

Abstract: A removable seal 10 is provided for positioning in a bore 14 around an element which, in use, passes therethrough. The seal comprises: a cylindrical outer sleeve 13 having an axial bore, the sleeve 13 having at least one engagement portion for engaging, in use, with an internal surface of the bore 14; and a sealing element 17 mounted on the cylindrical outer sleeve 13 for, in use, extending into the axial bore 14 to seal around the element passing therethrough.

Abstract: A tubular separation unit insertable into a caisson or tube for separating liquid from an upward flowing liquid/gas multi-phase stream, and including a centrifugal flow-induced liquid separator having a multi-phase gas/liquid inlet, a liquid outlet, and a gas stream outlet; a liquid transfer conduit connected to the liquid outlet of the flow separator; and a pump for pumping liquid, disposed below the separator and including a pump liquid inlet connected to the liquid transfer conduit and through which liquid separated in the separator is received, and a pumped liquid outlet through which separated liquid is, in use, caused to flow selectively.

Abstract: A tubular separation unit insertable into a caisson or tube for separating liquid from an upward flowing liquid/gas multi-phase stream, and comprising: a centrifugal flow-induced liquid separator having a multi-phase gas/liquid inlet, a liquid outlet, and a gas stream outlet; a liquid transfer conduit connected to the liquid outlet of the flow separator; and a pump for pumping liquid, disposed below the separator and including a pump liquid inlet connected to the liquid transfer conduit and through which liquid separated in the separator is received, and a pumped liquid outlet through which separated liquid is, in use, caused to flow selectively.

Abstract: An electrical connection across a peripheral surface through a sealed enclosure (34A) in a radial plane between a tubing hanger (5) and a surrounding support member (3). The connection involves a coupling element (17) in the tubing hanger and an electrical contact supporting shuttle (20) which can reciprocate from a position wholly within the support member, across the interface and into electrical connection with the coupling element, without producing any movement of a cable (9,10,11,15) leading into a sealed enclosure within the support. In certain embodiments (FIGS. 3-7), the shuttle (20) is driven by threaded engagement with a rotatable drive sleeve (30) and includes a sleeve (21) that is reciprocated over a stationary power core (22, 22'). The shuttle is also filled with a dielectric gel (26) contained within a flexible bladder (25). A sensor contact (35) can be used to indicate full retraction of the shuttle (FIG. 5).

Abstract: A wellhead having, instead of a conventional Christmas tree, a spool tree in which a tubing hanger is landed at a predetermined angular orientation. The tubing string can be pulled without disturbing the tree and access may be had to the production casing hanger for monitoring production casing annulus pressure and for the introduction of larger tools into the well hole without breaching the integrity of the well. In the embodiment described, a valve is used to open and close a fluid pressure passage between the production casing annulus and a production casing annulus monitoring port in the spool tree.

Abstract: A control system for controlling hydrocarbon flow from a well includes a hydrocarbon module and a separate control module. The hydrocarbon module includes one or more flow passages communicating with the flow of hydrocarbons from the well. Valves are disposed in the flow passages for opening and closing the passages to flow. Each valve includes a valve member having an open and a closed position. A biasing member is provided for biasing each valve member to the closed position. The control module is positioned adjacent the hydrocarbon module and includes an actuator member for each of the valve members. The valve member and actuator member are end to end such that the actuator member may be actuated to move the valve member to the open position. The valve members and actuator members engage along a common interface so as to allow the removal of the control module without removing the hydrocarbon module.

Abstract: Method for casing a hole drilled in a formation having an enlarged section located below a previously cased section. The method includes running casing into the enlarged section wherein the casing is of slightly smaller diameter than that present in the previously cased section, pumping cement into the annulus formed between the outer surface of the casing and the enlarged section of the formation, providing a valve arrangement in the casing to permit circulation of the cement between the annulus and an inner portion of the casing, securing the casing in position within the hole and hanging and packing off in the last casing string. Finally, the previously cased string is latched and sealed to the last casing string.

Abstract: A guide line attachment for releasably attaching a guide line to a guide post top or other portion of a sub-sea installation has three relatively movable spring loaded concentric sleeves, the relative movement of which can be used to releasably lock the attachment to the guide post top or other portion. Relative movement of the sleeves also activates a latch to releasably lock the sleeves to each other. The attachment may fit inside or outside a guide post top and may be pre-set so that it will or will not automatically relatch on release. The guide post tops have internal or external grooves for engaging the attachment locking means, and specially designed tools may be used to effect remote release sub-sea. The guide line attachment may be used for all stages of the drilling and production of a sub-sea oil well and avoids the present need to cut and replace guide lines at different stages in the life of a sub-sea well.

Abstract: A slurry of oil-impregnated cuttings from the use of oil based drilling mud and other unwanted slurries and fluids may be injected into the annulus of a sub-sea well and then into a porous formation through which the well has passed using apparatus on a guide base surrounding the sub-sea well head. The guide base comprises a coupling for a pipe extending down from the drilling rig, a one-way isolation valve and pipework leading to the outermost housing of the well. The outermost housing has ports to carry the slurry into the outermost annulus and inner housings may also have ports to carry this slurry into inner annuli. Inter housings also have a one-way check valve to control the injection. The guide base may have a cement circulation pipework and a cement and dump valve. The guide base may also be a retrievable base so that the injection apparatus may be reused.

Abstract: A mechanical actuator operated by electrical power suitable for actuating down hole equipment in a well, e.g. down hole safety valves, has an electric motor, a gear assembly with a mechanical advantage of at least 30:1, a two-part drive sleeve, the parts being connected by, e.g. splines so that the two parts can rotate together while capable of relative axial movement, an actuating sleeve moved axially by rotation of the drive sleeve, and a releasable lock operated by a solenoid to lock the two parts of the drive sleeve against relative axial movement. Rotation of the motor in one direction primes the actuator, rotating in the other direction actuates the equipment and the solenoid-operated releasable lock holds the equipment in the actuating position. If the solenoid is switched off, deliberately or by power failure, the lock is released allowing the equipment to return to its fail-safe position.

Abstract: A fail safe annulus valve for fluids has a valve area across the annulus with inlet and exit ports and a slide valve in the area capable of sliding to open or close the ports. The slide valve is biased to its fail safe position by a spring, is susceptible to being opened by independent pressure apparatus, and is also susceptible to movement by differential annulus fluid pressure across the valve. Thus while it fails safe, it can always be moved by differential annulus pressure. The valve may be used for the annuli of oil or gas wells (e.g. annuli used for artificial lift) and may be mounted on a packer of the annulus. It may also be used for closing other types of annuli.

Abstract: An electrical cable assembly is formed of a length of hollow pipe with means at either end for joining lengths of the pipe, one or more electrical cables within the pipe, and connectors with electrical contacts at either end of the cable(s) held within the ends of the pipe so that, on joining lengths of pipe, the connectors are also automatically joined to form an electrical path through the joint.

Abstract: A guide base for a sub-sea well is formed in two parts, an annular portion fixed to a conductor housing and a retrievable portion surrounding and releasably attached to the annular portion. The retrievable portion can be recovered and used elsewhere if a well is suspended or abandoned or changed for another type of guide base after drilling and before completion. A trawler board deflector can also replace the retrievable guide base portion, and a retrievable protective cap may be placed on the well head housing of a suspended well. A hydraulically-operated multi-purpose tool may be used for placing or retrieving any of the retrievable items.

Abstract: Guide posts for any part of a sub-sea oil or gas installation can be installed in or removed from a guide foot solely by vertical movement. The guide post end has a surrounding locking sleeve capable of sliding axially relative to the guide post end and there is at least one locking mechanism formed of a ring or segments on the guide post and co-operating with at least one groove in the guide foot. Upward movement of the guide post end relative to the locking sleeve locks the mechanism, and upward movement of the locking sleeve relative to the guide post end unlocks it. The mechanism may be automatically reset by the unlocking action so that guide posts may be transferred underwater without being brought back to the surface, although damaged posts can always be retrieved if required. Tools for unlocking and removing the guide posts are also described, one of the tools being capable of dealing with bent guide posts.

Abstract: A projecting actuation point and a hollow ROV-operable tool for subsea equipment both have a larger diameter surface and a smaller diameter surface, the former being nearest to the subsea equipment. The smaller diameter surface of the actuation point provides a coarse guidance and early alignment of the tool over the actuation point and the larger and smaller surfaces, which fit closely, provide in combination two sets of interfaces for final alignment.The principle can be applied to a wide variety of subsea parts. The actuation point can be a spigot for a valve or choke, a point for hydraulic or electrical connection, a point for both fluid injection and valve isolation or a coupling to link a subsea component with a subsea module or to a remote power source.