Abstract: A subsea fluid pressure-increasing machine includes an elongated member that is rotatable about a longitudinal axis. The machine also may include a plurality of impellers each having a leading edge, a trailing edge, a suction side, and a chord line defined by a line between the leading and trailing edges. Each impeller is fixedly mounted to the member such that a chord angle defined by an angle between the chord line and the rotation direction is less than or equal to a stall angle at which a maximum force is exerted on a fluid in a direction primarily parallel to the longitudinal axis when the member is rotated in the rotation direction. At least some of the impellers comprise one or more features that effectively reduce a pressure peak or specific loading of the suction side such that the axial length of the impeller is configured to be reduced without exceeding a desired specific load.

Abstract: An impeller blade that includes an impeller blade body constructed of a first material. The impeller blade body defines a leading edge that faces a direction of rotation. A second material couples to the leading edge. The second material is a more erosion resistant material than the first material. The second material extends over the leading edge a distance to absorb high angle impacts of droplets and/or particulate. A third material couples to at least a portion of the impeller blade body.

Abstract: A compressor includes impellers each having its chord angle less than its stall angle. The impellers can be used in a contra-rotating impeller arrangement without static diffusers. The contra-rotating impeller arrangement provides for much larger nominal flow rates than conventional single rotating impeller arrangements with the same chord angles. Accordingly, a surge free design is provided without excessively compromising the nominal flow rate. Techniques for enhancing stall characteristics of the impellers are also described.

Abstract: An impeller blade that includes an impeller blade body constructed of a first material. The impeller blade body defines a leading edge that faces a direction of rotation. A second material couples to the leading edge. The second material is a more erosion resistant material than the first material. The second material extends over the leading edge a distance to absorb high angle impacts of droplets and/or particulate. A third material couples to at least a portion of the impeller blade body.

Abstract: A subsea fluid pressure-increasing machine includes an elongated member that is rotatable about a longitudinal axis. The machine also may include a plurality of impellers each having a leading edge, a trailing edge, a suction side, and a chord line defined by a line between the leading and trailing edges. Each impeller is fixedly mounted to the member such that a chord angle defined by an angle between the chord line and the rotation direction is less than or equal to a stall angle at which a maximum force is exerted on a fluid in a direction primarily parallel to the longitudinal axis when the member is rotated in the rotation direction. At least some of the impellers comprise one or more features that effectively reduce a pressure peak or specific loading of the suction side such that the axial length of the impeller is configured to be reduced without exceeding a desired specific load.

Abstract: The axial reaction force generated by a subsea pump or compressor is partially counteracted by a pressure differential in a barrier fluid across a thrust element. The pressure differential is created using impellers or other structures on the thrust element that increases the barrier fluid pressure on one side of the thrust element when the main shaft of the pump or compressor is rotated. The pressure differential across the thrust element partially offloads the bearing surface of the thrust element.

Abstract: A compressor includes impellers each having its chord angle less than its stall angle. The impellers can be used in a contra-rotating impeller arrangement without static diffusers. The contra-rotating impeller arrangement provides for much larger nominal flow rates than conventional single rotating impeller arrangements with the same chord angles. Accordingly, a surge free design is provided without excessively compromising the nominal flow rate. Techniques for enhancing stall characteristics of the impellers are also described.

Abstract: A counter-rotating wet gas compressor for deployment and operation on the sea floor is described. The compressor has alternating rows of impellers, with each successive row of impellers being mounted a central hub or to an outer sleeve. According to some embodiments, no static diffusers are positioned between the alternating counter-rotating rows of impellers such that the design is structurally robust, compact and capable of compressing fluids that contain significant portions of liquid phase.

Abstract: Apparatus for homogenization of multi-phase fluid; the fluid including at least a first phase and a second phase a gaseous phase and a liquid phase; the apparatus including an inner reservoir fluidly communicative with an outer receptacle; the inner reservoir including an inlet for multiphase fluid, an outlet having a smaller cross sectional area than the body for outflow of the first phase and at least one opening into the outer receptacle for outflow of the second phase, the opening being spaced from the first phase outlet; wherein the outer receptacle has an inlet conduit having a neck which at least partially surrounds the inner reservoir outlet.

Abstract: A counter-rotating wet gas compressor for deployment and operation on the sea floor is described. The compressor has alternating rows of impellers, with each successive row of impellers being mounted a central hub or to an outer sleeve. According to some embodiments, no static diffusers are positioned between the alternating counter-rotating rows of impellers such that the design is structurally robust, compact and capable of compressing fluids that contain significant portions of liquid phase.

Abstract: Apparatus for homogenization of multi-phase fluid; the fluid including at least a first phase and a second phase a gaseous phase and a liquid phase; the apparatus including an inner reservoir fluidly communicative with an outer receptacle; the inner reservoir including an inlet for multiphase fluid, an outlet having a smaller cross sectional area than the body for outflow of the first phase and at least one opening into the outer receptacle for outflow of the second phase, the opening being spaced from the first phase outlet; wherein the outer receptacle has an inlet conduit having a neck which at least partially surrounds the inner reservoir outlet.

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: A method of, and apparatus for measuring the relative proportions of oil and water in a flowing multiphase fluid includes allowing the gas, oil and water phases of the multiphase fluid at least partially to separate, diverting at least some of the separated gas phase from the flowing fluid, into a bypass conduit, through a separating module, such as the tank of a homogenizing unit, where the gas phase tends to separate and collect above a pool of fluid, and measuring the relative proportions of oil and water in the undiverted fluid. A valve is located in the bypass conduit which has an inlet leading from the upper section of the tank (where gas collects) and an outlet joining the outlet pipe leading from the homogenizing unit downstream of metering apparatus.

Abstract: A method and system for sea-based handling/treatment of fluid hydrocarbons (oil) with associated gas comprise 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: A device for measuring fluid flow rates has a body defining a conduit for the fluid, the body having selectable first and second configurations, in the first configuration the body presents a first constriction in the conduit for measuring a first range of fluid flow rates, and in a second configuration the body presents a second construction in the conduit for measuring a second range of fluid flow rates, the second constriction being narrower than the first constriction, the body being arranged for operative connection to parts for determining the pressure difference between each constriction.

Abstract: A method of calculating the salt content of water in a multiphase flow which comprises irradiating a body of the multiphase flow with radiation of three distinct energy levels; measuring the intensity of the transmitted radiation at each of the energy levels, and using the measurements of transmitted radiation as obtained from calibration and radiation mass attenuation coefficients for hydrocarbons for each of the energy levels, to calculate a unique function for representing the salt content of the water. The three energy levels can as an example be provided by the radioactive isotope Barium 133 and the radiation mass attenuation coefficients for hydrocarbons can be calculated theoretically or derived from static calibration measurements. The invention is particularly suited for the measurement of water salinity in a stream comprising a mixture of oil, water, and gas, i.e., a multiphase flow, without separating the phases.