A system for hydrocarbon production comprising a host for receiving produced hydrocarbon; an offshore hydrocarbon production facility comprising: a production wellhead for connection to a subsea hydrocarbon reservoir; a production platform configured to receive produced fluid from the wellhead and being in fluid communication with the host via a long distance pipeline; wherein the wellhead is local to the production platform, and the production platform is configured to process the produced fluid to provide a semi-stable oil product suitable for exporting along the long distance pipeline to the host.

A system for hydrocarbon production comprising a host for receiving produced hydrocarbon; an offshore hydrocarbon production facility comprising: a production wellhead for connection to a subsea hydrocarbon reservoir; a production platform configured to receive produced fluid from the wellhead and being in fluid communication with the host via a long distance pipeline; wherein the wellhead is local to the production platform, and the production platform is configured to process the produced fluid to provide a semi-stable oil product suitable for exporting along the long distance pipeline to the host.

There is provided an apparatus 30 and method for conditioning the flow of a mixed phase flow from a supply pipe 101 from a hydrocarbon well. The apparatus 30 comprises an elongate reservoir 11 having a first end for receiving a multi-phase fluid flow from the supply pipe and a second closed end, there being provided a gas outlet 02 from the upper part of the first end, a liquid separation region downstream of the first end, and a liquid outlet 12 from the lower part of the liquid separation region; and a gas-liquid mixer to which the gas and liquid outlets are connected such that the separated gas and liquid may be recombined. The reservoir 11 may accommodate surges of liquid such that the flow rate from the liquid outlet is relatively invariant over time compared to that of the flow received by the apparatus.

There is provided an apparatus 30 and method for conditioning the flow of a mixed phase flow from a supply pipe 101 from a hydrocarbon well. The apparatus 30 comprises an elongate reservoir 11 having a first end for receiving a multi-phase fluid flow from the supply pipe and a second closed end, there being provided a gas outlet 02 from the upper part of the first end, a liquid separation region downstream of the first end, and a liquid outlet 12 from the lower part of the liquid separation region; and a gas-liquid mixer to which the gas and liquid outlets are connected such that the separated gas and liquid may be recombined. The reservoir 11 may accommodate surges of liquid such that the flow rate from the liquid outlet is relatively invariant over time compared to that of the flow received by the apparatus.

A subsea pump includes a liquid-gas inlet port for receiving liquid and gas into a first chamber, a plunger in a second chamber, a suction valve communicating the first chamber with a second chamber, a gas discharge conduit, a gas discharge valve communicating the first chamber with the gas discharge conduit, and a liquid discharge port for discharging liquid from the second chamber. The plunger retracts inwardly to create a vacuum in the second chamber that opens the suction valve and pulls liquid from the first chamber into the second chamber. The plunger extends outwardly against the suction to cause the suction valve to close and create a positive pressure that opens the gas discharge valve and forces the gas in the first chamber through the gas discharge valve into the gas discharge conduit. Liquid in the second chamber is discharged through the liquid discharge port via the positive pressure.

A subsea pump includes a liquid-gas inlet port for receiving liquid and gas into a first chamber, a plunger in a second chamber, a suction valve communicating the first chamber with a second chamber, a gas discharge conduit, a gas discharge valve communicating the first chamber with the gas discharge conduit, and a liquid discharge port for discharging liquid from the second chamber. The plunger retracts inwardly to create a vacuum in the second chamber that opens the suction valve and pulls liquid from the first chamber into the second chamber. The plunger extends outwardly against the suction to cause the suction valve to close and create a positive pressure that opens the gas discharge valve and forces the gas in the first chamber through the gas discharge valve into the gas discharge conduit. Liquid in the second chamber is discharged through the liquid discharge port via the positive pressure.

A top side-less pump system for managing multiphase fluid includes a pump subsystem having a suction and a discharge. A first gas liquid extraction unit has a multiphase fluid inlet and a liquid outlet. The liquid outlet is coupled to the suction for providing a liquid rich fluid to the bearing lubrications. An ejector is coupled to a gas outlet of the main gas liquid extraction unit to receive a gas rich fluid. A second gas liquid extraction unit is coupled to an outlet of the ejector. A water based lubrication liquid unit is coupled to the inlets of the pump and, after being energized at higher pressure, injected into the bearings through built in lubrication and cooling passages.

A top side-less pump system for managing multiphase fluid includes a pump subsystem having a suction and a discharge. A first gas liquid extraction unit has a multiphase fluid inlet and a liquid outlet. The liquid outlet is coupled to the suction for providing a liquid rich fluid to the bearing lubrications. An ejector is coupled to a gas outlet of the main gas liquid extraction unit to receive a gas rich fluid. A second gas liquid extraction unit is coupled to an outlet of the ejector. A water based lubrication liquid unit is coupled to the inlets of the pump and, after being energized at higher pressure, injected into the bearings through built in lubrication and cooling passages.

The present invention provides a drain apparatus (200) for use in a subsea pipeline to remove liquid from a multiphase flow in the subsea pipeline. The drain apparatus comprises a first channel (20) for carrying a multiphase flow comprising liquid and gas phases; and liquid extraction means (11, 12, 14, 18) for extracting the liquid phase from the multiphase flow in the first channel (20). The internal diameter of the first channel (20) is substantially the same as an internal diameter of a subsea pipe arranged to carry the multiphase flow in the subsea pipeline, such that a pig travelling along the subsea pipe can pass through the first channel (20). The present invention also provides a subsea pipeline comprising a subsea pipe for transporting a multiphase flow subsea; and at least one drain. The at least one drain is disposed partway along a gradient in the subsea pipe to reduce liquid holdup.

The present invention provides a drain apparatus (200) for use in a subsea pipeline to remove liquid from a multiphase flow in the subsea pipeline. The drain apparatus comprises a first channel (20) for carrying a multiphase flow comprising liquid and gas phases; and liquid extraction means (11, 12, 14, 18) for extracting the liquid phase from the multiphase flow in the first channel (20). The internal diameter of the first channel (20) is substantially the same as an internal diameter of a subsea pipe arranged to carry the multiphase flow in the subsea pipeline, such that a pig travelling along the subsea pipe can pass through the first channel (20). The present invention also provides a subsea pipeline comprising a subsea pipe for transporting a multiphase flow subsea; and at least one drain. The at least one drain is disposed partway along a gradient in the subsea pipe to reduce liquid holdup.