A flexible deployment system is used to deploy subsea/downhole well equipment or modules from a multi-purpose vessel without requiring a moon pool and a derrick or tower. The deployment system may include the vessel and a deployment frame disposed on the vessel. The deployment frame includes a protruding section extending as a cantilever beyond an external edge of the vessel, and the protruding section includes an aperture formed therein to facilitate construction of the well equipment or modules through the protruding section. The deployment system also includes an actuation assembly coupled to the protruding section to selectively transition the protruding section to a collapsed, split, or retracted orientation out of a deployment path of the well equipment or modules. The system allows for controlled deployment of well equipment or modules including at least a string of downhole tools or tubulars coupled end to end from the side of the vessel in a single trip.

A method and a system for providing fluid communication between a floating vessel and an installation, wherein the method connects a guiding line to a male stab arranged at an end portion of a fluid transfer hose. The guiding line is operatively connected to a pulling device, such as a winch, forming part of a fluid transfer unit having a female receptacle. The guiding line runs through the female receptacle, and a portion of the guiding line is pulled through the female receptacle until the male stab connects to the female receptacle.

Obstructing fluid plugs are removed from a base section of a riser, which base section extends between a receiving end connected to an upright section of the riser and an emitting end of the riser connected to a subsea template located on a seabed over a drill hole to a subterranean void into which fluid received via the riser is to be injected from the subsea template (120). The obstructing fluid plugs are removed either by injecting heated assisting from a storage container into an injection point in the base section and injecting heated assisting liquid from the vessel in the upright section of the riser, or a heating unit is controlled to heat the base section to a predetermined temperature, and thereafter maintain a temperature level here above or equal to the predetermined temperature.

A method of installing a subsea pipeline having a direct tie-in to a subsea structure includes, during introduction of the pipeline into the sea from a pipe laying vessel, applying a plastic deformation to a region of the pipeline at or close to an end of the pipeline to be tied-in and, either during or following tie-in, elastically deforming the region to increase its radius of curvature.

A method of removing a flexible line deployed between an offshore platform and a subsea structure, where the platform has a landing deck on which the flexible line is installed, the landing deck facing away from the platform towards an installation side. The method comprises: decoupling a topside end of the flexible line from the landing deck; lowering the topside end from the landing deck to the sea bed using a platform mounted winch, and detaching the winch from the topside end; moving the platform in a direction away from the installation side and positioning an installation vessel on the installation side; lowering a recovery line from the installation vessel and attaching an end of the recovery line to the topside or subsea end of the riser; raising the attached topside or subsea end onto the installation vessel from the seabed using the recovery line; and recovering the flexible line onto the installation vessel, whereupon the platform can be moved back to an operating position.

An offshore methane hydrate production assembly (1), having a tubing (41) extending into a subsea well (5) that extends down to a methane hydrate formation (7) below the seabed (3). A submersible pump (45) is arranged in the tubing (41). A methane conduit (35,35) extends down from a surface installation (49). A well control package (15) landed on a wellhead (13) is positioned at the upper end of the subsea well (5). Moreover, an emergency disconnection package (25) is arranged between the methane conduit (35,135) and the well control package (15). The tubing (41) is suspended from the well control package (15). Other aspects of the invention are also disclosed.

A riser (171) to be arranged for injecting fluid from a vessel on a water surface (111) into a subterranean void (150) beneath a seabed (130) is attached to a buoy (170) as follows. An ROV (350) is controlled to attach a winch wire (320) to a head end (300) of the riser (171). Then, the ROV (350) is controlled to lead the winch wire (320) via the buoy (170) to a winch unit (330) on a seabed (130) below the buoy (170). Thereafter, the winch unit (330) is controlled to pull up the head end (300) of the riser (171) to a bottom side of the buoy (170). Finally, the ROV (350) is 10 controlled to connect the head end (300) of the riser (171) to a connector arrangement (210) in the bottom of the buoy (170).

A flow line connector assembly has first and second parts respectively comprising a plug, and a socket configured to receive the plug; a restraining device to resist disconnection of the first and second parts when the plug is received in the socket; and flow tubes, wherein each of the plug and the socket has a respective flow tube and the flow tubes are adapted to interconnect to form Ca conduit for fluid to flow between the first and second parts when the plug is received in the socket.

A system for landing a subsea component includes a retention assembly configured to be coupled to the subsea component, the retention assembly including a first connector, a cable extending between the connector and a tensioning assembly, and a releasable lock configured to selectably actuate the tensioning assembly between a locked position and an unlocked position, wherein, when the tensioning assembly is in the unlocked position, a tensioning force is applied to the cable, and an anchoring assembly configured to anchor to a sea floor, the anchoring assembly including a second connector configured to be coupled to the first connector of the retention assembly.

A method of removing a flexible line deployed between an offshore platform and a subsea structure, where the platform has a landing deck on which the flexible line is installed, the landing deck facing away from the platform towards an installation side. The method comprises: decoupling a topside end of the flexible line from the landing deck; lowering the topside end from the landing deck to the sea bed using a platform mounted winch, and detaching the winch from the topside end; moving the platform in a direction away from the installation side and positioning an installation vessel on the installation side; lowering a recovery line from the installation vessel and attaching an end of the recovery line to the topside or subsea end of the riser; raising the attached topside or subsea end onto the installation vessel from the seabed using the recovery line; and recovering the flexible line onto the installation vessel, whereupon the platform can be moved back to an operating position.