Systems and methods for coupling a platform to a subsea wellhead are provided. The systems may include a riser extending between the platform and the subsea wellhead. The systems may further include an inner drilling riser tie-back connector (“ITBC”) coupled to an inner riser and having an outer body and an inner body. The inner body is at least partially disposed within the outer body, and the inner body is translatable along a longitudinal axis of the ITBC between a first unlocked position and a second locked position. The systems may additionally include a locking mechanism for the ITBC.

A drill device comprising: a pile configured such that same descends to a seafloor surface through a mooring installation device provided in a ship, and a part of the body thereof is fixed in an area of the seafloor surface as the upper surface thereof is pressurized in the vertical direction; a driving pipe configured such that same descends to the seafloor surface through a through-hole formed in the pile, the body thereof is inserted into a seafloor foundation, and same is recovered through the through-hole after excavation is completed; a chain, one end of which is fixed to one side of the pile, and the other end of which is introduced through the through-hole such that same is inserted into the seafloor foundation together with the driving pipe; and a drill bit unit.

The present invention provides a system for coupling between a bend stiffener (1) and a bell month (2) comprising a plurality of locking mechanisms (3), wherein each locking mechanism (3) is secured externally to the bell mouth (2) and comprises a movable lug (30) positioned such as to slope downwards, in which the lug (30) accesses the interior of the bell mouth (2) and is actuated by an elastic element (34) designed to exert pressure on the lug (30) in the direction of the interior of the bell mouth (2).

A mobile offshore drilling unit includes a plurality of electric thrusters to dynamically position the drilling unit, and a microgrid electric power generation system for providing power to the plurality of electric thrusters, the microgrid electric power generation system including at least one combustion generator electrically coupled to a main electric power bus and at least one thruster electric power system, the thruster electric power system including a thruster electric power bus, an additional electric power bus connected to the thruster electric power bus via an interface device, and a circuit breaker electrically coupling the additional electric power bus to a main electric power bus for isolating the thruster electric power bus from the main electric power bus in case of loss of power on the main electric power bus.

This disclosure includes subsea pumping apparatuses and related methods. Some apparatuses include one or more subsea pumps, each having an inlet and an outlet, and one or more motors, each configured to actuate at least one pump to communicate a hydraulic fluid from the inlet to the outlet, where the subsea pumping apparatus is configured to be in fluid communication with a hydraulically actuated device of a blowout preventer. Some subsea pumping apparatuses include one or more of: a desalination system configured to produce at least a portion of the hydraulic fluid; one or more valves, each configured to selectively route hydraulic fluid from an outlet of a pump to, for example, a subsea environment, a reservoir, and/or the inlet of the pump; and a reservoir configured to store at least a portion of the hydraulic fluid. Some apparatuses are configured to be directly coupled to the hydraulically actuated device.

A hydraulically driven underwater pumping system may include a pumping module connected to a subsea base. The subsea base may be connected to: a subsea producing well via a production line that carries the fluid produced by the subsea producing well; and a production unit via a riser and a service line. The hydraulically driven underwater pumping system may receive working fluid from the production unit via the service line. Additionally, a pump, located in the pumping module, may be driven hydraulically by the working fluid and pump the fluid produced by the subsea producing well to the production unit. The hydraulically driven underwater pumping system may mix the working fluid, after being used to drive the pump, with the fluid produced by the subsea producing well that is pumped to the production unit.

The invention relates to the introduction of pressurized fluid, e.g. acid, into a subsea well directly from a vessel (33). A fluid injection assembly (20) is fitted to the top of a subsea Xmas tree (3), the assembly (20) including fail safe closed valve (21) which is controlled via a hydraulic line (31) from the vessel. The hose and assembly and valve are designed with an internal bore allowing a large diameter ball to be dropped (required for acid stimulation). The subsea subsea control module (8) on the Xmas tree is controlled from the producing platform.

Installation for producing fluid such as crude oil having a floating support having at least two tanks, an undersea bottom-to-surface connection pipe having a first pipe portion on the sea bottom from a well head to the bottom end of a second pipe portion at the floating support, a first auxiliary pipe for transporting gas extending from the floating support to the bottom end of the second pipe, and a plurality of valves for isolating or putting into communication the first auxiliary pipe, for isolating or putting into communication the first production pipe portion and the second production pipe portion, end to end, and suitable for isolating or putting into communication the proximal end of the first production pipe portion and the bottom end either of a fourth auxiliary pipe rising directly to the surface, or a bottom portion of the first auxiliary pipe.

An intelligent system is provided for monitoring a subsea structure and delivering appropriate cathodic protection to desired areas of the subsea structure. According to an embodiment, the technique involves monitoring a cathodic protection potential level at an important location or locations of the subsea structure. Based on the data acquired via monitoring, a controller is able to apply voltage levels to the subsea structure so as to attain and modulate a desired cathodic protection level, e.g. a cathodic protection level within a range of about −800 mV to −950 mV (SCE). Consequently, undesirable overprotection and under protection are avoided and the subsea structure is adequately protected from corrosion while reducing undesirable production of hydrogen.

A subsea riser is installed by lowering at least one riser conduit to the seabed when piggybacked to an elongate support that comprises at least one flowline. The elongate support may be a pipeline bundle, which may be attached to one or more towheads in a towable bundle unit. The riser conduit may be in fluid communication with the flowline. At the seabed, a free end portion of the riser conduit is detached from the elongate support by releasing subsea-releasable fastenings. Then, with the elongate support and a root end of the riser remaining at the seabed, the detached free end portion of the riser conduit is lifted away from the elongate support to a riser support, such as a platform, an FPSO (floating production, storage and offloading vessel), or a buoy.