A method of conveying a production fluid from an offshore subsea well to an offshore vessel includes deploying an inflatable bladder from the offshore vessel, the inflatable bladder including a bladder valve, and fluidly connecting the inflatable bladder to an offloading port positioned at a seafloor, wherein the offloading port includes a port valve and is in fluid communication with one or more subterranean hydrocarbon-bearing formations. The method further includes opening the bladder and port valves to discharge the production fluid from the offloading port into the inflatable bladder, and thereby resulting in a substantially filled bladder, closing the bladder and port valves, and fluidly disconnecting the substantially filled bladder from the offloading port.

A method of conveying a production fluid from an offshore subsea well to an offshore vessel includes deploying an inflatable bladder from the offshore vessel, the inflatable bladder including a bladder valve, and fluidly connecting the inflatable bladder to an offloading port positioned at a seafloor, wherein the offloading port includes a port valve and is in fluid communication with one or more subterranean hydrocarbon-bearing formations. The method further includes opening the bladder and port valves to discharge the production fluid from the offloading port into the inflatable bladder, and thereby resulting in a substantially filled bladder, closing the bladder and port valves, and fluidly disconnecting the substantially filled bladder from the offloading port.

The invention provides a jumper termination apparatus for a subsea jumper flowline, a flow system incorporating a jumper termination apparatus, and a method of use. The jumper termination apparatus comprises a body, a jumper coupling means configured to couple the body to a jumper flowline, a connector coupling means configured to couple the body to a subsea manifold connector, and an access interface disposed on the body, arranged above the connector coupling means and vertically oriented to enable access from above. The body defines a first flow path from a coupled jumper flowline to a coupled subsea manifold connector, and a second flow path from the access interface to the first flow path or the subsea manifold connector. The access interface is configured to be connected to a termination apparatus of a second jumper flowline in a vertically stacked arrangement.

A method that consists of the following steps: depressuring and isolating the annular space; recording a first pressure and temperature prevailing in the annular space; injecting a given amount of a measuring gas into the annular space and isolating the annular space, the annular space remaining under negative pressure after the injection and isolation; measuring the given amount of measuring gas; recording a second pressure in the annular space after the isolation of the annular space; and determining the free volume of the annular space on the basis of the first pressure, the second pressure, the temperature, and the measurement of the given amount of measuring gas.

A petroleum pipeline safety system for preventing contamination of an environmentally sensitive area close to a pipeline is provided. The system includes a first portion of the pipeline including an upstream portion of the pipeline supplying a flow of fluid material and a flow restriction downstream of the first portion of the pipeline. The system further includes a second portion of the pipeline downstream of the flow restriction, receiving the flow of fluid material from the first portion and conveying the flow of fluid material through the environmentally sensitive area to a downstream portion of the pipeline. The flow restriction is configured to create a lower pipeline internal pressure within the second portion as compared to a pipeline internal pressure within the first portion. The system further includes a third portion of the pipeline downstream of the environmentally sensitive area and including the downstream portion of the pipeline.

A subsea hydrocarbon flow compression system (100) for receiving a hydrocarbon stream from at least one upstream flowline (102, 104) and supplying the hydrocarbon stream to at least one downstream flowline (106, 108) at an increased pressure, wherein the compression system comprises first and second compressor trains (110a, 110b), wherein each compressor train comprises an inlet port (112a, 112b) which is connectable to the at least one upstream flowline (102, 104); an outlet port (114a, 114b) which is connectable to the at least one downstream flowline (106, 108); a conditioning unit (116a, 116b) which is connected to the inlet port via a first flowline (118a, 118b); and a first flow path for the hydrocarbon fluid comprising a compressor (120a, 120b), which compressor is connected to the conditioning unit via a second flowline (122a, 122b) and to the outlet port via a third flowline (124a, 124b), wherein a controllable first valve (126) is arranged in the third flowline of the first compressor train for controlling hydrocarbon flow from the compressor to the outlet port of the first compressor train. A controllable second valve (128) is arranged in the second flowline of the second compressor train for controlling hydrocarbon flow from the conditioning unit to the compressor of the second compressor train. The system further comprises a first cross-over flowline (130) interconnecting the third flowline of the first compressor train upstream of the first valve and the second flowline of the second compressor train downstream of the second valve, wherein a controllable first cross-over valve (132) is arranged in the first cross-over flowline for controlling hydrocarbon flow through the first cross-over flowline.

A subsea hydrocarbon flow compression system (100) for receiving a hydrocarbon stream from at least one upstream flowline (102, 104) and supplying the hydrocarbon stream to at least one downstream flowline (106, 108) at an increased pressure, wherein the compression system comprises first and second compressor trains (110a, 110b), wherein each compressor train comprises an inlet port (112a, 112b) which is connectable to the at least one upstream flowline (102, 104); an outlet port (114a, 114b) which is connectable to the at least one downstream flowline (106, 108); a conditioning unit (116a, 116b) which is connected to the inlet port via a first flowline (118a, 118b); and a first flow path for the hydrocarbon fluid comprising a compressor (120a, 120b), which compressor is connected to the conditioning unit via a second flowline (122a, 122b) and to the outlet port via a third flowline (124a, 124b), wherein a controllable first valve (126) is arranged in the third flowline of the first compressor train for controlling hydrocarbon flow from the compressor to the outlet port of the first compressor train. A controllable second valve (128) is arranged in the second flowline of the second compressor train for controlling hydrocarbon flow from the conditioning unit to the compressor of the second compressor train. The system further comprises a first cross-over flowline (130) interconnecting the third flowline of the first compressor train upstream of the first valve and the second flowline of the second compressor train downstream of the second valve, wherein a controllable first cross-over valve (132) is arranged in the first cross-over flowline for controlling hydrocarbon flow through the first cross-over flowline.

A system for tethering a subsea blowout preventer (BOP) or well head is disclosed. In at least one embodiment, the system comprises an interface associable with the BOP, and more than one anchors disposed about the BOP. Each anchor is configured to carry or support a tensioning system arranged in operable association with a respective tether. Each tether is arranged so as to link a respective anchor with a respective operable means associated with the BOP. Furthermore, each of the respective operable means are configured in operable association with the interface such that tension in the tethers can be adjustable either individually or together as a group of two or more tethers, by way of the interface.

Method for connecting a termination hub (201a) to a porch hub (101a) at a subsea location by using a subsea fluid connection system (1). The connection system (1) comprises a porch part (100) with the porch hub (101a), a termination part (200) with the termination hub, and a connector (300). The method comprises a) landing the termination part (200) on the porch part (100) at a subsea location; b) moving the termination hub (201a) of the termination part (200) into alignment with the porch hub (101a) of the porch part (100); c) with the connector (300), connecting the termination hub (201a) to the porch hub (101a). The method further comprises d) after step c), actuating a moment arrestor arrangement (400), thereby further arresting the termination part (200) to the porch part (100). A subsea fluid connection system is also disclosed.

Method for connecting a termination hub (201a) to a porch hub (101a) at a subsea location by using a subsea fluid connection system (1). The connection system (1) comprises a porch part (100) with the porch hub (101a), a termination part (200) with the termination hub, and a connector (300). The method comprises a) landing the termination part (200) on the porch part (100) at a subsea location; b) moving the termination hub (201a) of the termination part (200) into alignment with the porch hub (101a) of the porch part (100); c) with the connector (300), connecting the termination hub (201a) to the porch hub (101a). The method further comprises d) after step c), actuating a moment arrestor arrangement (400), thereby further arresting the termination part (200) to the porch part (100). A subsea fluid connection system is also disclosed.