The invention relates to systems for producing oil and hydrocarbons in general, in deep water, using subsea wells and in apparatus which are interconnected in a drainage and production system. In this context, the invention relates to a mandrel multiplying device (1a, 1b, 1c, 1d, 1e, 1f) suitable for providing additional points between pieces of subsea apparatus, the device comprising a connector (2) for coupling to a mandrel of a subsea apparatus (8, 9), and at least two mandrels (3, 4, 5) suitable for providing points for connection to subsea lines (J1, J1′, J1″, J2, R1, R2, A1, A2, A3) which are connected to other pieces of subsea apparatus (8, 9) or to a production unit (13).

Disclosed are systems and methods for thermal management of subsea interconnecting conduit such as jumpers that provide cooling and heat retention of production fluids within the jumpers. In a jumper circuit, parallel sections of jumper are provided having differing amounts of heat transfer between surrounding seawater and production fluids flowing within. Valving is provided to control fluid flow between the parallel sections of jumper, thus controlling the amount of heat transfer between the surrounding seawater and the jumper circuit. A control system can be used to generate an alarm based on fluid temperature and/or fluid flow rate within the jumper circuit indicating the need to adjust the valving to manage the temperature of fluids within the jumper circuit. Changes may be needed particularly depending on the phase of production, e.g., early life, normal operation, shut down and late life operation.

Disclosed are systems and methods for thermal management of subsea conduits. A jumper that carries oil and/or gas produced from a subsea well in a subsea production facility located on a seabed has a first end for connecting to a first subsea component and a second end for connecting to a second subsea component. The jumper includes a jumper segment that is sloped relative to the horizontal, such that gravity assists with drainage of fluid from the second end of the jumper independent from fluid pressure in the jumper. At least a portion of the jumper is uninsulated to allow exchange of heat with seawater surrounding the jumper as produced fluid travels through the jumper. The amount of insulation on the jumper can be varied such that heat transfer from the production fluids to seawater surrounding the jumper circuit is adjusted as desired.

Disclosed are systems and methods for thermal management of subsea conduits such as jumpers that provide the ability to alternate between cooling and heat retention of production fluids within the conduit as needed depending on the phase of operation. Adjustable insulation elements are provided on the conduits so that convective heat transfer between surrounding seawater and the conduit can be allowed or reduced. A control system can activate an alarm indicating the need to adjust the insulation depending on the temperature and/or flow rate of fluids in the conduit. Conventional conduits can be retrofitted by adding adjustable insulation elements to enable thermal management.

It is disclosed a satellite well structure (300) and method for expanding a subsea satellite well system. The subsea satellite well structure (300) comprising:—a seabed-based foundation (330) supporting a subsea wellhead (340);—a first landing position (310) configured to receive a Christmas tree module (200) for interfacing the subsea wellhead (340);—a second landing position (320) configured to receive a subsea connection module (100) for connecting the Christmas tree module (200) to a hydrocarbon fluid export flowline; and—a plurality of Christmas tree guide posts configured to support the installation of the Christmas tree module; wherein the first landing position has a landing envelope defined by the plurality of Christmas tree guide posts, and wherein the second landing positions is arranged offset the landing envelope of the first landing position, (allowing:—the subsea connection module (100) to be landed on and retrieved from the seabed-based well structure (300) with the Christmas tree module (200) landed in the first landing position (310); and—the Christmas tree module (200) to be landed on and retrieved from the seabed-based well structure (300) with the subsea connection module (100) landed in the second landing position (320).

It is disclosed a satellite well structure (300) and method for expanding a subsea satellite well system. The subsea satellite well structure (300) comprising:—a seabed-based foundation (330) supporting a subsea wellhead (340);—a first landing position (310) configured to receive a Christmas tree module (200) for interfacing the subsea wellhead (340);—a second landing position (320) configured to receive a subsea connection module (100) for connecting the Christmas tree module (200) to a hydrocarbon fluid export flowline; and—a plurality of Christmas tree guide posts configured to support the installation of the Christmas tree module; wherein the first landing position has a landing envelope defined by the plurality of Christmas tree guide posts, and wherein the second landing positions is arranged offset the landing envelope of the first landing position, (allowing:—the subsea connection module (100) to be landed on and retrieved from the seabed-based well structure (300) with the Christmas tree module (200) landed in the first landing position (310); and—the Christmas tree module (200) to be landed on and retrieved from the seabed-based well structure (300) with the subsea connection module (100) landed in the second landing position (320).

A modular subsea fluid storage unit has a variable-volume inner tank having a rigid top panel and a peripheral wall that is flexible by virtue of concertina formation. The peripheral wall is extensible and retractable vertically while the horizontal width of the tank remains substantially unchanged. A side wall of a lower housing part surrounds and is spaced horizontally from the peripheral wall of the inner tank to define a floodable gap between the peripheral wall and the side wall that surrounds the tank. An upper housing part extends over and is vertically spaced from the top panel of the inner tank and overlaps the side wall to enclose the inner tank. The floodable gap and the upper housing part enhance thermal insulation and trap any fluids that may leak from the inner tank.

A method includes providing a lower platform block (300) including a first frame (315), a plurality of docking tubes (305) connected to the first frame, and a plurality of first conductor tubes (310) connected to the first frame. At least a first jacket connector block (400) including a second frame (415) and a plurality of second conductor tubes (405) connected to the second frame is releasably coupled to the lower platform block to align the second conductor tubes with the first conductor tubes. A platform deck block (500) including a third frame (515) defining a deck and a plurality of third conductor tubes (505) connected to the third frame is releasably coupled to the first jacket connector to align the third conductor tubes with the first conductor tubes.

A method includes providing a lower platform block (300) including a first frame (315), a plurality of docking tubes (305) connected to the first frame, and a plurality of first conductor tubes (310) connected to the first frame. At least a first jacket connector block (400) including a second frame (415) and a plurality of second conductor tubes (405) connected to the second frame is releasably coupled to the lower platform block to align the second conductor tubes with the first conductor tubes. A platform deck block (500) including a third frame (515) defining a deck and a plurality of third conductor tubes (505) connected to the third frame is releasably coupled to the first jacket connector to align the third conductor tubes with the first conductor tubes.

Subsea system (100) and method of installing the subsea system (100), the method comprising the steps of: —preparing a first foundation (1′) comprising at least a first dedicated position for receiving a first subsea station (3′, 13′), —providing the first foundation (1′) with at least a first guide system (4′), —installing the first foundation (1′) at a subsea location, —preparing at least a first subsea station (3′, 13′) comprising a first flow module (5′) for connection with a pipeline (6), —installing the at least first subsea station (3′, 13′) with the first flow module (5′) in the first dedicated position on the first foundation (1′), —preparing a pipeline (6) and providing the pipeline (6) with at least a first T-connection (7′) at a determined calculated position corresponding to the first dedicated position on the first foundation (1′), —installing the pipeline (6) and allowing the pipeline (6) to rest on the first guide system (4′) on the first foundation (1′) such that the first T-connection (7′) is arranged at or in the proximity of the first dedicated position on the first foundation (1′), —preparing a first piece of pipe (8′) and connecting the first T-connection (7′) of the pipeline (6) with the first flow module (5′) on the first subsea station (3′, 13′) using the first piece of pipe (8′).