Abstract: A submersible process environment for sub-sea processing is provided. Such environment can include a modular encapsulated unit having an interior volume and one or more processing units disposed therein, a first valve in fluid communication with the interior and exterior of the unit, and a second valve in fluid communication with the interior and exterior of the unit. The first valve and the second valve can be in fluid communication with the processing unit, and the processing unit can receive a fluid from the first valve and discharges the fluid to the second valve.

Abstract: A slug flow separator facilitates the separation of a mixture flow into component parts. The separator includes an upper-tier elongate conduit, a lower-tier elongate conduit and a plurality of spaced apart connectors. Each of the upper and lower-tier elongate conduits has an outlet and at least one of the upper and lower-tier elongate conduits has an inlet for receiving the mixture flow. The upper and lower-tier elongate conduits also each have a plurality of openings such that one connector of the plurality of connectors may interconnect one of the upper-tier elongate conduit openings with a one of the lower-tier elongate conduit openings. The connectors enable communication of at least one of a liquid component and the at least one of another liquid component and a gas component of the mixture flow therebetween.

Abstract: A continuous open discharge vacuum chamber for gravity feeding drill cuttings extracted from a cuttings source by vacuum and depositing them by gravity into a fluid. Embodiments include means for removing and recovery of drilling fluids, sizing the cuttings and relieving choke points and blockages.

Abstract: A method for control of liquid or liquid slugs in multi phase fluid pipelines, including a multiphase pipeline for the transportation of a fluid, consisting of mainly gas and some liquid such as water an/or gas condensate. The gas is evacuated via a gas separation unit connected to the multiphase pipeline to a second gas transport pipe, and the liquid is fed to a dedicated pipeline section acting as a buffer volume pipeline. The separation unit includes one or several vertical pipes connected at a distance from one another along the multiphase pipeline, whereby the gas is transported separately to a downstream processing facility on a platform or onshore or the like, and whereby the liquid proceeds to the loop which may preferably be an extension of the multiphase pipeline, or the liquid and gas may be re-combined and led in a common transport pipeline to the desired destination.

Abstract: A pressure driven pumping system includes a piston disposed within a first bore of a housing to separate a process chamber from a working chamber. A rod member coupled to the separating member extends into a reduced pressure chamber. The piston has a first face exposed to the process chamber and a second face exposed to the working chamber. The second face has an effective area less than an effective area of the first face. The housing may be placed in seawater at a selected depth. The process chamber can be in fluid communication with a well to pass well fluid into the process chamber at well pressure to move the piston, to discharge seawater from the seawater chamber. The working fluid, typically seawater in a subsea application, is pumped into the working chamber to move the piston, which discharges well fluid from the process chamber.

Abstract: An apparatus and corresponding method of use extracts, cools, and transports effluents from subterranean, sub-sea oil formations to distant shore based processing facilities. The effluents, mostly crude oil, are conveyed rapidly to a cold flow generator near the oil wellhead on the sea bottom using the cold seawater to chill the effluents to a dispersed mixture including generated solids. The mixture is transported close to sea bottom temperatures, slowly, with small pressure drops, in low-cost submerged bare pipes over long distances to on or near shore processing facilities that can produce useful hydrocarbon products more cost effectively than at sea processing facilities. The apparatus eliminates or minimizes the need for heated or insulated pipe, the need for large floating processing structures, the need for sub-sea processing equipment, and/or the need for chemical additions to production flow.

Abstract: A subsea well assembly has a string of casing with perforations leading to a producing zone and perforations leading to an injection zone. A string of production tubing extends into the casing in communication with the producing formation. A barrier separates the interior of the tubing from the injection zone formation. A subsea Christmas tree is located at the upper end of the well. A subsea separator is connected to a production outlet of the tree for separating waste fluid from the well fluid. A subsea injection pump pumps waste fluid from the separator back to the tree and into the injection formation.

Abstract: A drilling rig device (1) situated on the seabed (11), where the drilling rig (1) is sealingly enclosed against the surroundings, wherein the drilling rig (1) is liquid-filled and provided with a separator (16) arranged to separate material (17) from the liquid.

Abstract: A device for inhibiting severe slug flow in a multiphase fluid stream flowing through a pipeline and into a riser, wherein, the device is positioned immediately upstream of the riser and comprises at least one unit comprising (i) an upwardly inclined section of pipe having a lower end and an upper end and (ii) either a substantially horizontal section of pipe having a first end and a second end or a downwardly inclined section of pipe having an upper end and a lower end, wherein the lower end of the upwardly inclined section of pipe is connected either directly or indirectly with the pipeline, the upper end of the upwardly inclined section of pipe is connected either directly or indirectly with the first end of the horizontal section of pipe or with the upper end of the downwardly inclined section of pipe, and the second end of the horizontal section of pipe or the lower end of the downwardly inclined section of pipe is connected either directly or indirectly with the riser, and wherein the angle of inclinati

Abstract: A Vertical Annular Separation and Pumping System (VASPS) utilizing an isolation baffle to replace a standard pump shroud associated with an electrical submersible pump. The isolation baffle may be a one piece plate positioned so as to direct produced wellbore liquids around the electrical submersible pump motor to provide a cooling medium to prevent overheating and early failure of the electrical submersible pump.

Abstract: A system for producing hydrocarbon fluids from a subsea formation comprises at least one producing well (1) penetrating the formation (2) for producing hydrocarbon fluids. At least one dummy well (7) is hydraulically connected to the at least one producing well (1) for routing the hydrocarbon fluids from the producing well to the dummy well. At least one pump (8) is disposed in the at least one dummy well. The pump takes suction flow from the dummy well (7) and boosts the flow energy of the discharge flow of hydrocarbon fluids.

Abstract: In subsea multiphase pumping systems, the use of a gas-liquid cylindrical cyclone (GLCC) as a separator to recirculate liquid from pump discharge to pump suction, especially during high gas inlet conditions from a multiphase petroleum stream. Further contemplated is protection of the pump from momentary high gas inlet conditions due to an incoming slug flow profile from a petroleum stream, via transforming a naturally varying multiphase petroleum stream into separated phases for measured distribution to the pump suction and ensuring a minimum liquid flow.

Abstract: A pipe separator for the separation of fluids, for example the separation of oil, gas and water in connection with the extraction and production of oil and gas from formations beneath the sea bed. The pipe separator includes a pipe-shaped separator body (1) with an inlet and outlet that principally corresponds to a transport pipe (4, 7) to which the pipe separator is connected. The pipe separator further includes a pipe bend or loop (2) arranged in the pipe separator or in connection with its outlet to form a downstream fluid seal in relation to the pipe separator body (1), which is designed to maintain a fluid level in the pipe separator, but which also allows the pipe separator (1) and the loop (2) to be pigged.

Abstract: A subsea petroleum production system for artificial lift, including a pumping module coupled to a flow base, the system being installed downstream of a Wet Christmas Tree (WCT) on the seabed. The pumping module includes at least one submersible centrifugal pump (SCP) inclined with respect to the vertical direction at an inclination of up to 85 degrees from the vertical direction, wherein a flow in said at least one pump is ascending.

Abstract: Systems and methods for the production of hydrocarbons from a wellbore. One or more combination tools can be disposed along a casing string inserted into a wellbore. Each combination tool can contain a body having a bore formed therethrough; a sliding sleeve at least partially disposed in the body; one or more openings disposed about the body at a first end thereof, and a valve assembly and a valve seat assembly at least partially disposed within the bore at a second end thereof. While initially permitting free bidirectional flow of fluids within the casing string, the sliding sleeve within each combination tool can be manipulated to close the valve within the tool, thus permitting pressure testing of the casing string. The sliding sleeve can be further manipulated to open the one or more openings thereby permitting hydraulic fracturing and production of a hydrocarbon zone surrounding the combination tool.

Abstract: A cuttings processing system processes return fluid recovered while drilling a wellbore at an offshore location. The processing system includes a separator having an inlet receiving the return fluid, an accelerator coupled to the inlet that accelerates the return fluid, and a conical spinning member that receives the accelerated return fluid from the accelerator and applies a centrifugal force to the return fluid. The acceleration provides the return fluid with a tangential velocity that substantially matches the rotational speed of the conical spinning member. The separator also has a liquid discharge port that discharging the substantially liquid component to a tank or pipe and a solids discharge opening that discharges the substantially solid component out of the separator. In one embodiment, a conveyance device transports the solids component from the separator to a selected location on the offshore facility.

Abstract: A pipe separator is for separation of fluids, for example separation of oil, gas and water in connection with extraction and production of oil and gas from formations under a sea bed. The pipe separator comprises an extended, tubular separator body having a diameter at inlet and outlet ends that is mainly equal to or slightly greater than a diameter of a transport pipe to which the separator body is connected. A cyclone is arranged upstream of the separator body for separation of any gas present. An electrostatic coalescer is incorporated in and constitutes an integrated part of the separator body.

Abstract: A control system and control method for controlling a modular apparatus for extracting petroleum and/or generating electricity based on subsurface data as well as market prices of electricity and/or petroleum. One or more probes measure subsurface total pressure, partial pressure of carbon dioxide, partial pressure of hydrogen, oil flow rate, gas flow rate, underground temperature, and/or viscosity of the oil. The control system/method controls the apparatus based on the subsurface parameters by controlling an injection module and/or a gas separator module to increase or decrease output of driver gas. The control system/method may also control the injection module and/or the gas separator module to increase (or decrease) output of driver gas when the market price of electricity decreases (or increases) and/or petroleum increases (or decreases).

Abstract: A system inserted between the base of a riser (5) and a production well flowline for collecting an effluent consisting of at least a gas phase and a liquid phase, includes a capacity (1) including an inlet port for the effluent and two outlet ports, one in the upper part of said capacity for the gas phase, the other in the lower part for the liquid phase communicating with the base of the riser, a gas supply line (2) connecting the gas outlet port to the riser at a predetermined height H, including a flow control valve (3), and an instrumentation set for locating the level of the liquid/gas interface in the capacity, a computer receiving the instrumentation data for determining the instructions for controlling said flow control valve so as to adjust the volume of gas fed at height H into the riser.

Abstract: A system for mitigating slugging in the conveyance of hydrocarbons in a flowline includes a first portion of flowline that extends substantially longitudinally along a declining surface. The first flowline portion carries multiphase hydrocarbons. A second portion of flowline extends upward from adjacent the first portion of flowline, and is in fluid communication with the first portion of flowline. A slug-mitigating region is between the first and second portions of flowline so slug-mitigating assembly receives the hydrocarbons from the first portion of flowline and conveys the hydrocarbons to the second portion of flowline. The slug-mitigating region has consecutively joined tubular segments that are each arcuate along a predetermined arcuate angle, with substantially uniform cross-sections. The first portion of flowline can be a subsea flowline extending along a sea floor, and the second portion of flowline can be a riser.

Abstract: The invention comprises a sealing body (15)-separatingseparating device) which can be used to separate fluids in risers used in offshore oil production from drilling vessels at the sea surface. The invention is characterized in that the sealing body (15) can be placed in position above the wellhead (13) using several appropriate methods and, in an especially preferred application, by utilizing an installation tool (27) which is not sealing against the inner wall of the riser and which contains a suitable positioning means (28), and that the body (15) which forms a seal against the inner wall of the riser separates fluids during the replacement of drilling fluid with water and of water with drilling fluid. The body (15) can be displaced using hydraulic force upwards in the longitudinal direction of the riser in that fluid is pumped at a relatively high pressure down the externally located smaller pipes (9, 10, 11) of the riser.

Abstract: The invention relates to a device for removal and filtration of drilling fluid at top hole drilling, where a suction module (10) comprises an extended, pipe-formed body (30), open at the top and which is arranged to an ocean-bottom penetrating pipe, through which a drill stem is led for drilling of the top hole, and where the pipe-formed body (30) comprises at least one outlet passage (32) in the pipe wall for export of return drilling fluid from the bore hole to a pump module (12). The invention is characterized in that the pipe-formed body (30) comprises a filtration device with through openings, where the mentioned openings are arranged to let through, to at least one outlet passage (32), return drilling fluid containing suspended material, such as swelling clay and stones, having a size that is less that the diameter of the inlet pipe of the pump or the openings of the pump.

Abstract: A system for supporting multiple-well-site, offshore, hydrocarbon-bearing fields, each well-site has one or more wells. In general, the system first comprises a floating vessel that is relocatable from a first subsea well-site to a second subsea well-site. The system also comprises two separate systems: (1) an operations control system for providing subsea well-site operations such as power and communications; and (2) an intervention system for conducting intervention services to an individual subsea well such as workover services and maintenance services. The operations system may provide control to wells and other subsea equipment at either the first well-site or the second well-site, regardless of the location of the floating vessel. The intervention system may provide workover and/or maintenance to subsea equipment or individual wells at the well-site at which it is located.

Abstract: A subsea and modular tanker-based hydrocarbon production system comprising a plurality of interlinked individual tank units which is wholly submersible, is wholly detachable from, and wholly re-attachable to, its associated subsea wellhead infrastructure. Modularity of the interlinked tank unit system allows for the processing, measurement, and storage of hydrocarbons from a wide variety of offshore hazard and water-depth related conditions and situations. In addition to being both detachable and re-attachable, the modularity of the system provides for a number of unit systems to be conjoined at surface and towed to market.

Abstract: Methods and apparatus for flowing a subsea well. The method comprises the steps of: supplying a multi-phase medium from a subsea tree 18 to a removable separator package 10; separating the multi-phase flow into one or more phases at the desired pressures, the pressures being controlled by one or more pressure control devices 51, 67, 71, 75, 76, 77, 78, 79 on one or more outlets from the separator package 10; and analysing each of the one or more phases to determine the amount and quality of products produced by the well.

Abstract: An inline well fluid separator is movable for pigging operations. The separator assembly has a housing with an inlet port and an outlet port. A separation unit is carried within the housing. The separation unit has an operational position in alignment with the ports to cause well fluid to flow through the separation unit. The separation unit will move to a storage position within the housing outside of the flow path to enable a pipeline pig to pass.

Abstract: A sub-sea well intervention vessel includes a dynamically positionable tanker and direct well intervention equipment mounted on the tanker deck. The intervention equipment includes drilling equipment for performing underbalanced drilling and hydrocarbon liquid separation. A separate production riser is provided so that simultaneous drilling and production can be performed via separate risers. The driller riser is selectively disconnectable from the well so that the tanker can be dynamically repositioned over the well. A turret mooring system is provided such that the production riser can remain in operation during repositioning about the turret. The hydrocarbon liquid separator is connected to a separator of the production plant.

Abstract: A preferred embodiment of the inventive fluid delivery system comprises a vertical liquid/vapor separator and riser assembly that comprises a multi-phase separator inlet, a vapor outlet and riser, and a liquid outlet port connected to a hydraulically-driven centrifugal pump. By controlling the operational speed of the pump, the level of the separated liquid within the separator can be controlled without the need for control valves. The vertical separator is capable of low pressure operation and large variations in controlled liquid levels within the separator, allowing the relatively slow reaction time pump to control the liquid level from low pressure wells penetrating low pressure reservoirs.

Abstract: Water that is produced during offshore hydrocarbon processing, such as hot produced water accompanying hydrocarbons taken from subsea reservoirs, or cold water resulting from heating LNG (liquified natural gas) to convert it to gas, is changed in temperature to be closer to that of the surrounding sea using apparatus of minimal cost. The apparatus includes a mixer tube (52) that lies totally submerged in the sea and a nozzle (54) that receives the produced water and that has a nozzle end (76) lying in a middle portion of the mixer tube. A location of the mixer tube middle portion at the nozzle end has an inside diameter (A) much larger than the nozzle end outside diameter (B) to induce the through flow of sea water from the surrounding sea through the mixer tube. The produced water is pumped to a high enough pressure to create turbulence in the mixer tube immediately downstream of the nozzle end to better mix the produced and sea waters.

Abstract: A subsea well fluid processing system has a separator for separating heavier and lighter components of well fluid flowing from a subsea well and directing the lighter components to flow to a surface processing facility. A choke is located downstream of the separator for limiting the flow rate of well fluid. The separator has a cylindrical chamber having a length at least ten times its diameter. A coalescing unit located in the chamber causes water droplets in the well fluid to coalesce into larger droplets. A dielectrophoresis unit having undulating sheets spaced close to each other is also located in the chamber. The sheets of the unit are supplied with an electrical potential to force the water droplets into predetermined passage portions to form high water content sections of liquid. Bypass valves allow backflushing of one of the separators while others continue to operate.

Abstract: A method utilizes the energy of water that flows out from a high-pressure reservoir. Water and hydrocarbons are separated in a down-hole separator and are brought separately to the seabed. In a first aspect the energy of the water is utilized to inject the water into an underground formation with a lower pressure. In a second aspect the energy is utilized to drive a turbine which in turn is driving a pump for pressurizing hydrocarbons. The invention utilizes a method and an arrangement to control the separator by control valves on the well head for each phase.

Abstract: A subsea process assembly for separating a multiphase flow, the assembly comprising: an inlet for a multiphase medium; a pressure reducing means for reducing the pressure of the multiphase flow from the inlet and creating a source of energy; a multiphase separator for separating the multiphase input into individual phases; and a pumping system for, in use, pumping at least one of the desired individual phases to a delivery point by utilizing at least some of the energy from the source of energy.

Abstract: A method and a system for separating the phases of a multiphase fluid from one or more wells. The system includes at least one first gravity separator and at least one second gravity separator, and elements for conducting the fluid from the well or wells to the first and second gravity separator(s). The system includes elements for selectively conducting the fluid to the first and second gravity separators either in parallel or in subsequent steps depending on the properties of the well fluid and process conditions.

Abstract: A system for use in down hole operations, the system comprising a wellhead; a BOP ram package connected at one end to the wellhead and having an axial bore extending from the wellhead to the other end; a device above the other end of the BOP ram package for isolating the pressure of the wellhead; a fluid take off between the pressure containing means and the BOP ram package; a separator in communication with the fluid take of such that, in use, a multi-phase medium obtained from the well can be separated into its constituent phases; and a pressure control device on each of one or more outlets from the separator for allowing the system to be operated at different wellhead pressures.

Abstract: A GTL facility for a fixed offshore hydrocarbon production platform which comprises a deck attached to a base that is secured to the sea floor. The GTL facility comprises a syngas reactor for converting natural gas into syngas and a liquids production unit for converting the syngas into a hydrocarbon liquid. Furthermore, at least one of the syngas reactor and the liquids production unit comprises a catalyst which is constructed using PI micro-reactor technology. As a result, the GTL unit is sufficiently small to be located on the deck of the platform.

Abstract: There is provided a buoyancy system for a structure having at least one component being substantially stationary with respect to the bottom of a water covered area. The system comprises a set of buoyancy modules of engineered materials to apply an identified amount of buoyancy. The set of buoyancy modules is attached to the structure at a set of buoyancy load transfer locations. The set of buoyancy modules comprises layers of the engineered materials. The engineered materials comprise a substantially reinforced axial layer, a substantially reinforced hoop layer; and a leak prevention layer.

Abstract: Methods and arrangements for production of petroleum products from a subsea well. The methods comprise control of a downhole separator, supplying power fluid to a downhole turbine/pump hydraulic converter, performing pigging of a subsea manifold, providing gas lift and performing three phase downhole separation. Arrangement for performing the methods are also described.

Abstract: Exemplary embodiments include a method and a device for temporary storage of solid particles such as drill cuttings from a hole section for surface casing in a wellbore. In certain embodiments, the device having at least one collecting device placed on the seabed near a template over the mouth of a well. When the receptacle element in the collecting device is to be emptied, the collecting device is brought up to and on board a vessel on the surface of the sea.

Abstract: A subsea system for processing a fluid emanating from one or more subsea wells, comprising a fluid processing circuit and a base module (3) provided with at least one receiver (40) for receiving an insert module (4-8) comprising an appliance that forms part of the fluid processing circuit. The receiver (40) comprises a cavity (30) for accommodating the insert module (4-8). The insert module (4-8) is provided with a flange (31), which is adapted to bear on a corresponding flange (32) of the receiver (40) when the insert module (4-8) is mounted therein, a watertight seal (33) being arranged between said flanges (31, 32) so as to seal the space between the receiver (40) and the part of the insert module (4-8) received therein from the surrounding sea water.

Abstract: A subsea system for separating a multiphase fluid emanating from one or more subsea wells, comprising a foundation structure (1) secured to the seabed, a header piping module (2) adapted to be mounted to the foundation structure (1), a separator piping module (3) adapted to be removably mounted to the header piping module (2), and one or several insert modules (4–8), each of which comprising a processing appliance of the subsea system and being adapted to be removably mounted to the separator piping module (3).

Abstract: An offshore hydrocarbon production system in which gases are economically stored for transport. After the produced hydrocarbons are separated into liquid (crude oil) and gases, the gases are separated into heavy and light gases. The heavy gases, which consist primarily of propane and butane, are stored as LPG (liquid petroleum gas) in a refrigerated LPG tank. The light gases (methane and other light gases) are hydrated and the ice crystals are stored in a refrigerated hydrate tank.

Abstract: A system for separating fluids from a hydrocarbon well production fluid mixture at a subsea location has a centrifugal separator (16) for separating the mixture into gas and liquid. A hydrocyclone separator (32) then separates the liquid into oil and water and an oil-in-water sensor (38) detects the amount of oil in water leaving the separator. If the sensor (38) detects that the water contains more than the prescribed amount of oil, the water is recirculated through the hydrocarbon separator (32) for removal of further oil form water. The hydrocyclone separator (32) has a level interface sensor (66) and if this sensor detects that the oil/water interface is not within prescribed limits for optimum separation of the oil and water, the amount of oil removed from the separator is adjusted until the oil/water interface is within the prescribed limits.

Abstract: A power supply assembly, which is placed subsea and is connected to an umbilical from a platform, supplies electrical power to subsea equipment. The power supply assembly supplies power during drilling operations to a pump for pumping drilling fluid from the sea floor to the sea surface. During production operations, the power supply assembly provides power to a booster pump to pump the well fluid away from the subsea well for collection. The subsea power supply assembly optionally also provides power to electrically charged portions of subsea separators that remove water from the oil in the well fluid. The booster pump the pumps the oil from the separator away from the subsea wellhead for collection.

Abstract: A system for offloading LNG (liquified natural gas) from a tanker (26) in shallow waters, for regasing, or heating the offloaded LNG to produce gaseous hydrocarbons, or gas, for pressurizing the gas, and for flowing the gas to an onshore station (56), includes a structure that is fixed to the sea floor and projects above the sea surface and aids in mooring the tanker. In one system, the structure that is fixed to the sea floor is a largely cylindrical tower (12) with a mooring yoke (20) rotatably mounted on its upper end. A floating structure (14) such as a barge that weathervanes, has a bow end pivotally connected to a distal end of the yoke, so the barge is held close to the tower but can drift around the tower with changing winds, waves and currents. The tanker is moored to the barge so the barge and tanker form a combination that weathervanes as a combination.

Abstract: A system for offloading LNG (liquified natural gas) from a tanker (26) in shallow waters, for regasing, or heating the offloaded LNG to produce gaseous hydrocarbons, or gas, for pressurizing the gas, and for flowing the gas to an onshore station (56), includes a structure that is fixed to the sea floor and projects above the sea surface and aids in mooring the tanker. In one system, the structure that is fixed to the sea floor is a largely cylindrical tower (12) with a mooring yoke (20) rotatably mounted on its upper end. A floating structure (14) such as a barge that weathervanes, has a bow end pivotally connected to a distal end of the yoke, so the barge is held close to the tower but can drift around the tower with changing winds, waves and currents. The tanker is moored to the barge so the barge and tanker form a combination that weathervanes as a combination.

Abstract: A method for processing oil from oil wells having water bound locations whereby it is necessary to place the process containment vessels upon host structures that are floating and subjected to a swaying motion caused by the wave action of the water in which the host structures float. The process containment vessels are of a vertical cylindrical configuration to minimize their footprint and to mitigate the effect of tilting on the spatial process geometry inside of the vessels and further the vessels contain internal baffles that create horizontal flow patterns inside of the vertical vessel for a more efficient gravity separation process.

Abstract: A sub-sea submersible compressing apparatus having at least one compressor tank. A compressor tank is configured to receive gas from a gas/liquid separator and has an inlet for water. The compressor further comprises a pump to pump water from the compressor tank thereby drawing gas into the compressor tank from the gas/liquid separator. Valves are provided to shut off gas flow from the liquid/gas separator and to permit gas flow from the compressor tank to a predetermined location such as a recovery line for transferring the gas to the surface or other location. The gas contained within the compressor tank is compressed by allowing water to flow back into the compressor tank, thereby compressing the gas and forcing it from the compressor vessel. Two or more compressor tanks can be provided to facilitate a continuous operation by timing of the water flow to and from each of the compressor tanks.

Abstract: A method and system for sea-based handling/treatment of fluid hydrocarbons (oil) with associated gas include a first separation step in a high-pressure separator (18) installed on the sea bed, from which is output an oil flow containing an essentially predefined percentage of residual gas. The oil containing residual gas is carried through a riser (22) up to a surface vessel/production ship (12), where it is subjected to a second separation step in a second separator (24) incorporated in a low-pressure surface plant on board the vessel (12), this separated residual gas being used as fuel for direct/indirect generation of electric power for the operation of the underwater and above-water sections of the system. Water and gas produced in the first separation step is returned to a suitable reservoir by the use of a multiphase pump.

Abstract: There is provided a buoyancy system for a structure having at least one component being substantially stationary with respect to the bottom of a water covered area. The system comprises a set of buoyancy modules of engineered materials to apply an identified amount of buoyancy. The set of buoyancy modules is attached to the structure at a set of buoyancy load transfer locations. The set of buoyancy modules comprises layers of the engineered materials. The engineered materials comprise a substantially reinforced axial layer, a substantially reinforced hoop layer; and a leak prevention layer.

Abstract: A subsea well intervention vessel including a dynamically positionable tanker and direct well intervention equipment mounted on a deck of the tanker. The direct well intervention equipment is mounted on a superstructure above the main deck of the tanker and includes equipment for underbalanced non-rotating drilling and hydrocarbon liquid separation. The liquid separation equipment is coupled to storage tanks of the tanker so as to receive separated hydrocarbon liquids for storage purposes.