WO2018062997A1

WO2018062997A1 - Umbilical installation method and system

Info

Publication number: WO2018062997A1
Application number: PCT/NO2017/050224
Authority: WO
Inventors: Bjørgulf Haukelidsæter EIDESEN
Original assignee: Statoil Petroleum As
Priority date: 2016-09-30
Filing date: 2017-09-13
Publication date: 2018-04-05
Also published as: GB201616658D0; GB2554465A

Abstract

A system and method of laying a subsea umbilical termination head of a subsea umbilical is disclosed. The method comprises deploying a termination head having at an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability. The method further comprises landing the termination head at a landing structure of a subsea structure, the subsea structure having at least one interface providing at least one of said capabilities in common with the termination head.

Description

UMBILICAL INSTALLATION METHOD AND SYSTEM

FIELD

The invention relates to subsea umbilical installation and, in particular, to landing and connecting services to a subsea structure.

BACKGROUND

Subsea umbilical are deployed on the seabed to supply necessary control, energy (electric/ hydraulic), and chemicals to subsea oil and gas wells, subsea manifolds and any subsea system requiring remote control. A single umbilical may include control, energy and chemicals in a single cable or hose. Alternatively, the various lines can be provided in separate cables and hoses. For example, the electrical power and fibre optic control lines might be provided in one cable and the hydraulic and/ or chemicals might be provided in another cable if required.

In a typical process a subsea umbilical is laid on the sea bed from a topside facility using a lay vessel. In this case the umbilical has a topside umbilical termination unit (TUTU) and a Subsea Umbilical Termination Assembly (SUTA) which has an end termination and, for example, an associated mud mat - other forms of umbilical termination assembly are known. The interface between the umbilical and the termination is comprised typically of an umbilical armour termination and/or a mechanical anchoring device for the tubes, bend stiffener/limiter, and tube or hose-end fittings. If the umbilical contains electric cables/fibre optics, then penetrator(s) and/or connectors may also be incorporated.

The object of the laying process is to deposit the SUTA near or on a landing structure on the subsea structure, for example at a subsea distribution unit (SDU), production tree or Christmas tree (XT) or wellhead template. Typically the SUTA is then winched into place for connection to the subsea structure either directly or more typically using Jumpers (Also known as frying leads, such electrical frying leads (EFL) and hydraulic flying leads (HFL)). A pull-in and connection tool may be used to complete the connection of the umbilical end termination to the SUTA. A Remotely operated vehicle may be used to establish connection between a pull-in wire of the pull-in and connection tool and a pull-head of the umbilical. The connection tool then connects the umbilical head to, for example, a stoking hub, including a mechanical lock of the umbilical head to the stoking hub. A connector and seal assembly is then required to connect all the flow lines and electrical/ optical lines. A single SUTA may be connected to multiple well heads via jumpers allowing a single umbilical to provide services to a plurality of subsea control modules via the SUTA. At present subsea umbilical UTA's are deployed from a laying vessel and installed subsea in a separate procedure, for example. Figure 3 is exemplary of an end termination 10 of a Subsea Umbilical Termination Assembly (SUTA). A SUTA will typically include an umbilical termination head (UTH) in which the umbilical is permanently terminated, flying leads to connect the UTH to a hydraulic distribution module (HDM), a mud mat foundation assembly, for example with a stab and hinge over mechanism. A stab and hinge over type mud mat is employed when the intention is to connect the umbilical to a subsea distribution unit.

In figure 3, the end termination 10 has a full set of connections for distributing electrical power and signals and hydraulic fluids (for example) to the subsea control units. In this case there is an HDM having a hydraulic connector, Multiple Quick Connect (MQC) plate 11. The chemical and hydraulic lines are routed to the MQC plate 11 through tubes 12 shown through a cut away portion of figure 3. The end plate or mounting structure has front padeyes 13. An electrical distribution module (EDM) has electrical power and signal connector 14 to which the power and communication lines of the umbilical are routed via cable service loop 15 shown through a cut away portion of figure 3. The total length of such an end termination 10 may be approximately 3850 mm. Figure 3 also shows a bend stiffener or bend restrictor 16 which is part of the umbilical, and a Subsea Termination Interface, which has a transition spool 17 and a strength body 18. Tube welds 19 in the STI are shown in a cut away portion of figure 3. Recently, optical wireless subsea communication has been developed for subsea applications. For example, Sonardyne BlueComm™ is a wireless system that uses LED light or lasers for data transfer. It is envisaged that the technology can be used, for example, in wireless ROV telemetry, local control of AUV systems etc. There is also, so called Light Fidelity (Li-Fi), which is a bidirectional, high-speed and fully networked wireless communication technology similar to Wi-Fi. It is a form of visible light communication and a subset of Optical Wireless Communications (OWC) and could be a complement to RF communication (Wi-Fi or cellular networks), or even a replacement in contexts of data broadcasting. It is wireless and uses visible-light communication or infrared and near-ultraviolet instead of radio-frequency spectrum, part of optical wireless communications technology, which carries much more information, and has been proposed as a solution to the RF-band width limitations.

At the same time subsea inductive power transfer products are coming onto market. There are many different techniques for laying and installing subsea umbilicals but all are complex and expensive. In particular the hard wiring of termination heads to subsea structures, whether directly or by use of jumpers (flying leads), is time consuming, and expensive since it normally requires a separately scheduled installation procedure often requiring different vessels, which increases the cost. There are also harsh regions with short installation seasons, in which as much work as possible must be performed in the short installation window. Thus optimising the installation sequence as much as possible is valuable. Also removing subsea electrical and fiber optic connectors will remove many failure modes.

SUMMARY

The invention provides in a first aspect, a method of laying a subsea umbilical termination head of a subsea umbilical, comprising: deploying a termination head having at an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability; landing the termination head at a landing structure of a subsea structure, the subsea structure having at least one interface providing at least one of said capabilities in common with the termination head.

The termination head and subsea structure may be equipped with interfaces providing both of said capabilities. The capabilities may be provided by a single interface on each of the termination head and subsea structure. The interfaces may require no mechanical connection. There may be no mechanical connection between the interfaces.

The landing structure may provide a retaining tool configured to receive and retain an umbilical termination head in position relative to said at least one interface of the subsea structure. The retaining tool may be configured to maintain the position of the umbilical head with a maximum distance from the said at least one interface of the subsea structure. The subsea structure may be a subsea manifold template, a manifold cluster, or a PLEM, the subsea structure being associated with a plurality of well head trees. The manifold may include a further wireless interface for connecting to an SCM of each well head tree, each wireless interface being supplied with power and/ or communication signals from the interface associated with the landing structure.

The interface associated with the landing structure may be connected for at least one of power transmission or communication transmission to at least one further wireless interface associated with the subsea structure. The umbilical termination head may be mechanically coupled to termination head of a second umbilical before deployment of the mechanically coupled umbilical termination heads in subsea umbilical laying process.

In a second aspect, the invention provides a subsea umbilical laying method, comprising mechanically coupling an umbilical termination assembly at an end of a first umbilical to an umbilical termination assembly at an end of a second umbilical, and subsequently deploying the mechanically coupled ends of the first and second umbilical together in a subsea umbilical laying process, wherein said termination heads each comprise an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.

The invention also provides a system comprising: a subsea umbilical termination head of a subsea umbilical, comprising an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability; a subsea structure having a landing structure and an interface associated with the landing structure, the interface providing at least one of said capabilities in common with the termination head.

The termination head and subsea structure may be equipped with interfaces providing both of said capabilities. The capabilities may be provided by a single interface on each of the termination head and subsea structure.

The interfaces may require no mechanical connection. There may be no mechanical connection between the interfaces.

The landing structure may provide a retaining tool configured to receive and retain an umbilical termination head in position relative to said at least one interface of the subsea structure. The retaining tool may be configured to maintain the position of the umbilical head with a maximum distance from the said at least one interface of the subsea structure.

The subsea structure may be a subsea manifold template, a manifold cluster, or a PLEM, the subsea structure being associated with a plurality of well head trees. The manifold may include a further wireless interface for connecting to an SCM of each well head tree, each wireless interface being supplied with power and/ or communication signals from the interface associated with the landing structure.

The interface associated with the landing structure may be connected for at least one of power transmission or communication transmission to at least one further wireless interface associated with the subsea structure.

The umbilical termination head may be mechanically coupled to termination head of a second umbilical, wherein each termination head comprises an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.

The invention also provides a system comprising first and second umbilicals having termination heads, wherein the termination heads are mechanically coupled and each comprise an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.

DRAWINGS

The invention will now be described in more detail, and by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a schematic of a serial imbilcial TUA landed in a fork of a landing structure in accordance with an embodiment;

Figure 2 is a schematic of a system in accordance with the present invention

Figure 3 is a side view of a generic umbilical end termination

DETAILED DESCRIPTION

Using a termination head having one or both of, inductive power transfer capability, and optical wireless subsea communication capability, allows a subsea umbilical to be installed at a subsea structure easily, cheaply and quickly. The subsea structure must have at least one capability in common with the termination head and conveniently both if the termination head is equippped with both. The termination head may be an integrated umbilical including other services (chemical, hydraulic and other fluids). Conveniently, however, the other services will be provided, if needed, by separate lines. Providing separate lines for power and communications on the one hand and fluids on the other, allows more flexibility in field architecture.

In an embodiment, therefore, a subsea umbilical including a termination head having both inductive power transfer capability and optical wireless subsea communication capability, is provided - other services being supplied separately. In addition a subsea structure is provided which also has inductive power transfer capability and optical wireless subsea communication capability. Specifically, inductive power can be transferred from the termination head to the support structure and wireless communication signals provided to the support structure from the umbilical via the termination head. Obviously, at least the optical communication is conveniently two- way so that control signals can be supplied to the support structure and reporting messages can be returned to the top side facility for monitoring purposes for example. Whilst any subsea structure requiring such services can be equipped according to the invention it is envisaged that the subsea structure may be subsea template or manifold, specifially, a template manifold housing a plurality of subsea Christmas trees, a cluster manifold having a plurality of surrounding Christmas trees, or even a Pipeline End Manifold (PLEM) having only one or two associated Christmas trees. A reference to a manifold in this document means a reference to any such manifold unless dictated otherwise by the context. A subsea distribution unit (SDU) could also be provided with a landing structure and the necessary interface. The SDU could then be connected either by a hard wired jumper or even using a jumper suing wireless interfaces.

With respect of subsea wireless communication, products from Sonardyne such as BlueComm™ can transfer 10-20 Mbit/sec up to approximately 100 meters and 1 Mb per/sec up to 200m distance. The technology uses LED light for data transfer, which does not use much power for data transmission, and can transfer 1Gbit data using the energy stored in a single D-cell battery (large flashlight battery). Upsides of this system is that it does not introduce latency in using its optic LED light telemetry and has a transparent Ethernet interface which means that it is, therefore, applicable for most subsea applications.

With respect to inductive power transfer, products such as Sonardyne's Bluelogic™ connectors, can achieve power transfer of 2000W per connector, which is sufficient for all subsea control and instrumentation. The Blue logic's connectors are presently envisaged as local connectors for various subsea applications. The present invention envisages using wireless technology for terminating umbilicals; and further such that wireless technology is used to terminate the umbilical at a subsea structure (in particular a subsea manifold or template) and a further wireless interface is used to connect the XTs to the subsea structure to receive the services provided by the terminated umbilical.

In co-pending application GB1615015.3 (filed 5 September 2016) Is described a subsea umbilical laying method, comprising mechanically coupling an umbilical termination assembly at an end of a first umbilical to an umbilical termination assembly at an end of a second umbilical, and subsequently deploying the mechanically coupled ends of the first and second umbilical together in a subsea umbilical laying process. The coupled end terminations may be landed subsea together on the sea bed. The mechanical coupling may comprise one or more of a shackle, a bolt, a gyve, and a pin.

GB1615015.3 discloses in an embodiment that the mechanically connected termination heads are landed on the seabed or at a landing structure of a subsea structure, and then connected to the subsea structure in a single process. An example of the connection is by way of flying leads or jumpers. The mechanically connected termination heads may be connected to each other for power, communications and fluid transport either directly or via the subsea structure.

The entire contents of GB1615015.3 are incorporated herein by reference.

In the present invention, it is envisaged that the mechanically connected termination heads are connected for power and/ or communication signals wirelessly using inductive coupling for power and wireless communication technology for communication signals. Similarly the mechanically coupled termination heads may be connected each to the subsea structure in the same way (inductively and/ or using wireless communication means) and may be connected to each other for power and communications via the subsea structure.

Figure 1 shows a serial UTA (or UTH) 20 integrated in an umbilical 1. The reference to "serial UTA" is a UTA connected in series, meaning that the umbilical is terminated, but a new termination head follows right after, thus starting the next part of the umbilical. The two termination heads, one ending and one starting, are connected mechanically, thus connecting the two umbilicals together (as discussed above in relation to GB1615015.3. But the end termination and the start termination can also be one assembly. Thus being an inline serial element as shown in Figure 1, where the umbilical will have one such element at each of the locations where there will be subsea wells or equipment in need of power and signal. The UTA 20 uses inductive power transfer and wireless optical communication interfaces 21 for transmission to a receiving interface 22 in a landing structure 23 of a subsea structure 24. The receiving interface 22 may be a two-way interface (transceiver) for power and/ or communications. A two-way communications interface will most often be desirable. Direct line of sight is not necessary for subsea optical wireless communication to successfully transmit a signal. In the present embodiment both power and communication signals are provided by the umbilical. In other embodiments only one of the services is provided. In particular, power may be provided locally, requiring only communication signals from the top side. This may allow more flexibility in the maximum distance between the UTA 10 and the receiving interface 22. Power generation may be local or supplied separately by wired connection to local storage. There may be a power supply in the umbilical in addition to local storage and/ or generation. Each subsea structure 24 is provided with a support structure (for example a manifold frame) and a landing structure 23 (landing box or landing frame). The subsea structure 24 provides for integration of the equipment for receiving and sending signals, receiving power, and mechanical interfaces for landing the UTA onto the landing structure 23. It is necessary to supply communication signals and power at each required location, but in some cases there may be a local network also.

An umbilical 1 is installed by landing the UTA 20 on a fork 26 of the landing structure

23. Any method of landing the UTA 20 may be used, for example a winch system (not shown) or a ROV (not shown) may be used. In the present invention, however, no jumpers or flying leads are required to be installed subseqeunt to landing the UTA 20; the umbilical 1, once landed, is ready to deliver power and data communication services. Specifically it is envisaged that no separate physical connection is made between the inductive power and wireless optical communication interface 21 and the receiving interface 22. Instead it is envisaged that the head is physically retained in the landing structure 23 by a retaining means. The fork 26 is an example of a mechanical retaining tool that retains the UTA 20 in a fixed position in the landing structure 23 at least spatially relative to the support structure 24. Suchretaning tools are well known in the art and are not dicussed in detail here. The retaining tool may be provided with a clamp to ensure the position of the termination head is fixed.

The exact nature of the retaining means is not important; the retaining means should suffice to maintain a minimum distance between the UTA 20 and the support structure (specifically the receiving interface 22 on the support structure) of the subsea structure

24. Retaining the UTA 20 within the landing structure 23 should be sufficient to ensure power and wireless communication can be performed reliably and efficiently. The interface could be located in the landing structure 23.

The landing structure 23 includes inductive power transfer and optical wireless subsea communication capability; receiving interface 22 may include a transceiver for optical wireless communication. In the embodiment of figure 2, the landing structure 23 (or support structure of subsea structure 24) is hardwired (by a jumper/ flying lead) to an inductive power plate and optical wireless communication interface on the subsea structure for transferring power and communication signals to a subsea control module (SCM) of an XT (see figure 2).

In figure 2, a UTA 2 has been landed in a fork 26 of a landing structure 23, having a receiving interface 22 for transferring optical communications and for inductive power transfer. We note here that separate interfaces can be used for the power and communications, but they can also be provided in a single interface. The BlueLogic™ connector provides an optical communication power transfer in a single connector.

The landing structure 23 is hard wired by jumpers 27 to two separate power and communications interfaces 28, which are positioned to transfer optical communication signals and for inductive power transfer to a receiving interface of a respective SCM 29 of respective XTs 30. Using the p re-installed jumpers 27 on the subsea structure between these two wireless interfaces, mans that it is not necessary to have subsea connections (jumpers/ flying leads) between the XTs and the manifold; the XT and UTA can be installed fester and with reduced offshore work requirement. It is then also easier to retrieve and install components in operations, if you do not have to disconnect a lot of jumpers. Again it is envisaged that the interfaces 28 do not have a mechanical connection to the interfaces of the SCMs 29. The connection between the interfaces 28 and the SCMs could more conveniently use wireless interfaces that are nevertheless mechanically tethered to ensure efficient energy transfer for example.

In accordance with the method described above, in the embodiment of figure 2, the UTA 20 has been landed in the fork 26 and is immediately available to transfer power and communications signals to the well heads 31 , via respective XTs 30 using wireless and inductive connections as described above. Embodiments of the invention have been described with reference to the drawings. Variations may suggest themselves to the skilled person without departing from the scope of the invention as defined in the claims.

Claims

CLAIMS:

1. A method of laying a subsea umbilical termination head of a subsea umbilical, comprising:

deploying a termination head having at an interface providing at least one of: inductive power transfer capability; and

optical wireless subsea communication capability;

landing the termination head at a landing structure of a subsea structure, the subsea structure having at least one interface providing at least one of said capabilities in common with the termination head.

2. The method of claim 1 wherein the termination head and subsea structure are equipped with interfaces providing both of said capabilities.

3. The method of claim 2 wherein the capabilities are provided by a single interface on each of the termination head and subsea structure.

4. The method of anyone of claim 1, 2 or 3, wherein the interfaces require no mechanical connection.

5. The method of any one previous claim, wherein the landing structure provides a retaining tool configured to receive and retain an umbilical termination head in position relative to said at least one interface of the subsea structure.

6. The method of claim 5, wherein the retaining tool is configured to maintain the position of the umbilical head with a maximum distance from the said at least one interface of the subsea structure.

7. The method of any one previous claim, wherein the subsea structure is a subsea manifold template, a manifold cluster, or a PLEM, the subsea structure being associated with a plurality of well head trees.

8. The method of claim 7 wherein the manifold includes a further wireless interface for connecting to an SCM of each well head tree, each wireless interface being supplied with power and/ or communication signals from the interface associated with the landing structure.

9. The method of any one previous claim, wherein the interface associated with the landing structure is connected for at least one of power transmission or communication transmission to at least one further wireless interface associated with the subsea structure.

10. The method of any one preceding claim wherein the umbilical termination head is mechanically coupled to termination head of a second umbilical before deployment of the mechanically coupled umbilical termination heads in subsea umbilical laying process.

11. A subsea umbilical laying method, comprising mechanically coupling an umbilical termination assembly at an end of a first umbilical to an umbilical termination assembly at an end of a second umbilical, and subsequently deploying the mechanically coupled ends of the first and second umbilical together in a subsea umbilical laying process, wherein said termination heads each comprise an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.

12. A system comprising:

a subsea umbilical termination head of a subsea umbilical, comprising an interface providing at least one of:

inductive power transfer capability; and

optical wireless subsea communication capability;

a subsea structure having a landing structure and an interface associated with the landing structure, the interface providing at least one of said capabilities in common with the termination head.

13. The system of claim 12 wherein the termination head and subsea structure are equipped with interfaces providing both of said capabilities.

14. The system of claim 13 wherein the capabilities are provided by a single interface on each of the termination head and subsea structure.

15. The system of anyone of claim 12, 13, or 14, wherein the interfaces require no mechanical connection.

16. The method of any one of claims 12 to 15, wherein the landing structure provides a retaining tool configured to receive and retain an umbilical termination head in position relative to said at least one interface of the subsea structure.

17. The method of claim 16, wherein the retaining tool is configured to maintain the position of the umbilical head with a maximum distance from the said at least one interface of the subsea structure.

18. The system of any one of claims 12 to 17, wherein the subsea structure is a subsea manifold template, a manifold cluster, or a PLEM, the subsea structure being associated with a plurality of well head trees.

19. The system of claim 18 wherein the manifold includes a further wireless interface for connecting to an SCM of each well head tree, each wireless interface being supplied with power and/ or communication signals from the interface associated with the landing structure.

20. The system of any one of claims 12 to 19, wherein the interface associated with the landing structure is connected for at least one of power transmission or communication transmission to at least one further wireless interface associated with the subsea structure.

21. The system of any one of claims 12 to 20, wherein said umbilical termination head is mechanically coupled to termination head of a second umbilical, wherein each termination head comprises an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.

22. A system comprising first and second umbilicals having termination heads, wherein the termination heads are mechanically coupled and each comprise an interface providing at least one of, inductive power transfer capability, and optical wireless subsea communication capability.