Apparatus and method

Abstract

A first subsea system includes a lower marine riser package (LMRP) 160, an emergency disconnect package (EDP) 120, and a flexible joint 120 that is located below the emergency disconnect package and i

Description

TECHNICAL FIELD The present invention relates, generally, to an apparatus and method for reducing load on a wellhead. More particularly, the invention relates to a slimline lower marine riser package and emergency disconnect package, flexible connecting joint, and a method of connecting the same. BACKGROUND TO THE INVENTION Wellhead fatigue poses a continuing challenge in the oil and gas industry, particularly as production moves into increasingly hostile environments, wells deepen, requiring longer drilling and production times, and well pressure / temperature increases. Over time, the effects of cyclic loading due to wave action moving the mobile offshore drilling unit (MODU), production vessel, or well intervention vessel (WIV) (hereafter both referred to as “vessel”), and riser to which the wellhead connects, and vortex-induced vibration (VIV) around the subsea structures, leads to accumulation of damage to the wellhead. If this is not detected and remedied early, structural failure can result, threatening well integrity. One form of mitigation of this risk is to include an emergency disconnect package (EDP) as part of the lower marine riser package (LMRP). If the vessel experiences severe wave action, for example, that drags the vessel beyond its maximum distance from the vertical alignment with the well (in some cases, as much as 15° from the well centre), and endangers the riser connections, the EDP is a means of rapid, safe disconnection from the well before the load on the wellhead exceeds tolerable thresholds. At present the EDP / LMRP connectors that are used are very heavy, and costly, with the potential 15° extremes of flex built into the connector itself. Commonly a stress joint is used, disposed above the EDP, between the EDP and the bottom of the riser. The stress joint is configured to reduce the bending moment and reduce the load on the wellhead connector. It would be beneficial to provide a system that allows disconnection of the EDP by a straight pull even at the extremes of vessel movement from the well centre, while also being smaller, simpler, and less costly. A further problem with vessel movement is the travel of wireline through the completion. With a 5°-15° drift away from well centre and the corresponding angle of the riser, passing through the completion could be very tight and the wireline may struggle to get through the resulting small internal radius. As stress joints are very long, this is not an issue. It would therefore be beneficial to provide a system that further allows passage of wireline and tools through the ERP / LMRP and connector without requiring the vessel to be directly overhead to avoid hang-off. It would also be beneficial for the system to be sufficiently small / slimline to pass through a rotary table. This would remove the need to crane or drag the EDP / LMRP in under the rotary table to be assembled in the moon pool, resulting in a faster and safer operation. SUMMARY OF THE INVENTION According to the present invention there is provided a subsea system comprising a lower marine riser package, emergency disconnect package, and a flexible joint, wherein the flexible joint is disposed below the emergency disconnect package and on or in the lower marine riser package. This system is particularly advantageous as it provides a compact, cost-effective connection between the lower marine riser package (LMRP) and the emergency disconnect package (EDP) that flexes in response to movement - for example of the vessel that the riser is connected to. A suitable flexible joint may be e.g. a FlexJoint® product available from Oil States Industries, Inc. As the flexible joint is connected above the LMRP, but below the EDP, this offers the advantages that the bending moment experienced by the flexible joint is lower as it is lower down, and the angle of bending is lower. This reduces the fatigue experienced by the wellhead and increases its usable lifetime, and bending in response to movement occurs beneath the EDP and therefore the EDP can remain aligned with the riser, making disconnection easier via a straight pull. Optionally the flexible joint comprises an internal bore that is at least 13 5 / 8” (approx. 35cm) diameter. This allows passage of tools, wireline and the like through the flexible joint even when the subsea system is angled at up to 15°. Optionally, the flexible joint is configured to remain connected to the LMRP when the EDP is retrieved. According to the present invention there is further provided a method of installing a subsea system comprising the steps of: providing an emergency disconnect package (EDP), a flexible joint, and a lower marine riser package (LMRP); connecting the emergency disconnect package to the flexible joint, and the flexible joint to the lower marine riser package; connecting the lower marine riser package to a Christmas tree installed on a wellhead. Optionally the method comprises disconnecting at least a portion of the subsea system. Optionally the method comprises activating the EDP. Optionally the method comprises disconnecting the EDP from the flexible joint. Optionally the flexible joint remains connected to the LMRP after disconnection of the EDP. Optionally the subsea system comprises a hydraulic connector, and optionally the method comprises connecting the LMRP to the hydraulic connector. Optionally the hydraulic connector is then connected to the Christmas tree. According to the present invention there is further provided a subsea system comprising a frame; a lower marine riser package; an emergency disconnect package; and a flexible joint disposed between the lower marine riser package and the emergency disconnect package; wherein the frame is configured to at least partially surround the lower marine riser package, emergency disconnect package, and flexible joint; and wherein the subsea system is adapted to be lowered through a rotary table of an offshore oil and / or gas vessel during deployment. Optionally the subsea system is configured to be less than 49.5 inches (approximately 126cm) in external diameter. Advantageously, restriction of the diameter of the subsea system to 49.5” allows the subsea system to pass through the rotary table of a vessel instead of each component being craned or dragged in under the rotary table for stacking in the moon pool. This reduces the amount of assembly time required and significantly increases safety on the vessel. Optionally the lower marine riser package comprises at least one ball valve. Optionally the at least one ball valve comprises at least one cutting edge. Optionally the at least one ball valve is configured to cut lines passing through the subsea system, for example wireline. Optionally the subsea system comprises at least one hydraulic connector. Optionally the hydraulic connector is configured to connect to a Christmas tree. Optionally the hydraulic connector comprises at least one groove that extends at least partly around an outer surface of the hydraulic connector. Optionally the groove may be a helical slot, a j-slot, or similar. Optionally a guide is configured to sit over the hydraulic connector. Optionally the guide is a Christmas tree guide. Optionally the guide comprises a cylindrical portion. Optionally the cylindrical portion is configured to at least partially fit over the hydraulic connector. Optionally the guide comprises at least one pin or similar protrusion that extends from its internal surface. Optionally the pin extends from an internal surface of the cylindrical portion of the guide. Optionally the at least one pin is configured to fit within the groove. Optionally the groove and pin arrangement orients the Christmas tree guide in the correct position for installation on the tree, optionally without requiring any further guidance e.g. a guide frame. Optionally the subsea system comprises at least one accumulator. Optionally the at least one accumulator is disposed above the EDP. Optionally the at least one accumulator is coupled to a control system, hydraulic system, or similar via at least one hydraulic coupling. Optionally the hydraulic coupling is disposed below the hydraulic connector. Optionally the hydraulic coupling is positioned between the hydraulic connector and a mandrel. Optionally the hydraulic coupling is positioned inboard of the connector and mandrel. In other words, optionally the hydraulic coupling is positioned radially inward of the external surface / diameter of the hydraulic connector and / or mandrel. Traditionally, the hydraulic coupling may be mounted on plates outboard of / external to the hydraulic connector and mandrel. By positioning the hydraulic coupling so that it does not protrude or extend beyond the radial dimensions of the hydraulic connector or mandrel, this has the clear advantage that the overall size of this section of the system can be more compact and slimline in comparison to traditionally coupled systems that include plates. According to the present invention there is further provided a method of installing a subsea system comprising: connecting an emergency disconnect package (EDP), a flexible joint, and a lower marine riser package (LMRP) above a rotary table of an offshore oil and / or gas vessel; picking up the subsea system; and lowering the subsea system through the rotary table. Optionally the method comprises assembling the subsea system such that the external diameter of the subsea system does not exceed 49.5” (approx. 126 cm). Optionally the method comprises connecting hydraulic conduits via at least one hydraulic coupling that is disposed within the 49.5” (-126 cm) envelope of the subsea system. Optionally the method comprises positioning at least one accumulator within the 49.5” (-126 cm) envelope of the subsea system. Optionally the method comprises connecting at least one accumulator above the EDP. Optionally the method comprises connecting the at least one accumulator to a multiplex control system. Optionally the method comprises connecting the LMRP to a hydraulic connector. Optionally the hydraulic connector comprises a slot track on an external surface. Optionally the method comprises mounting a connector housing on the hydraulic connector. Optionally the connector housing at least partially surrounds the hydraulic connector. Optionally the connector housing comprises at least one pin configured to project from an internal surface of the connector housing. Optionally the at least one pin is resiliently biased towards the hydraulic connector. Optionally the method comprises mounting the connector housing by aligning the at least one pin with the slot. Optionally the resilient bias of the pin projects the pin into the slot. Optionally the method comprises aligning a Christmas tree guide by rotating the connector housing around the hydraulic connector. Optionally the slot of the hydraulic connector comprises stops or similar features that ensure that the Christmas tree guide is correctly aligned. The accompanying drawings illustrate presently exemplary embodiments of the disclosure and together with the general description given above and the detailed description of the embodiments given below, explain, by way of example, the principles of the disclosure. In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawings are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. Specific embodiments of the present invention are shown in the drawings, and herein will be described in detail, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results. The following definitions will be followed in the specification. As used herein, the term "wellbore" refers to a wellbore or borehole being provided or drilled in a manner known to those skilled in the art. The wellbore may be ‘open hole’ or ‘cased’, being lined with a tubular string. Reference to up or down will be made for purposes of description with the terms "above", "up", "upward", "upper" or "upstream" meaning away from the bottom of the wellbore along the longitudinal axis of a work string toward the surface and "below", "down", "downward", "lower" or "downstream" meaning toward the bottom of the wellbore along the longitudinal axis of the work string and away from the surface and deeper into the well, whether the well being referred to is a conventional vertical well or a deviated well and therefore includes the typical situation where a rig is above a wellhead and the well extends down from the wellhead into the formation, but also horizontal wells where the formation may not necessarily be below the wellhead. Similarly, ‘work string’ refers to any tubular arrangement for conveying fluids and / or tools from a surface into a wellbore. In the present invention, e-line, slick e-line, slickline or wireline is the preferred work string. The various aspects of the present invention can be practiced alone or in combination with one or more of the other aspects, as will be appreciated by those skilled in the relevant arts. The various aspects of the invention can optionally be provided in combination with one or more of the optional features of the other aspects of the invention. Also, optional features described in relation to one embodiment can typically be combined alone or together with other features in different embodiments of the invention. Additionally, any feature disclosed in the specification can be combined alone or collectively with other features in the specification to form an invention. Various embodiments and aspects of the invention will now be described in detail with reference to the accompanying figures. Still other aspects, features and advantages of the present invention are readily apparent from the entire description thereof, including the figures, which illustrates several exemplary embodiments and aspects and implementations. The invention is also capable of other and different embodiments and aspects and its several details can be modified in various respects, all without departing from the scope of the present invention as defined by the claims. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention. Accordingly, the drawings and descriptions are to be regarded as illustrative in nature and not as restrictive. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including", "comprising", "having" "containing" or "involving" and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents and additional subject matter not recited and is not intended to exclude other additives, components, integers or steps. In this disclosure, whenever a composition, an element or a group of elements is preceded with the transitional phrase "comprising", it is understood that we also contemplate the same composition, element or group of elements with transitional phrases "consisting essentially of”, "consisting", "selected from the group of consisting of”, “including” or "is" preceding the recitation of the composition, element or group of elements and vice versa. In this disclosure, the words “typically” or “optionally” are to be understood as being intended to indicate optional or non-essential features of the invention which are present in certain examples, but which can be omitted in others without departing from the scope of the invention as defined by the claims. All numerical values in this disclosure are understood as being modified by "about". All singular forms of elements, or any other components described herein including (without limitations) components of the downhole tool are understood to include plural forms thereof and vice versa. BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings: Figure 1 shows schematic view of a prior art example of a subsea system comprising an emergency disconnect package (EDP), a lower marine riser package (LMRP), and a flexible joint; Figure 2a shows a schematic view of an example subsea system in accordance with the present invention, comprising an EDP, an LMRP, and a flexible joint in a resting, vertical, configuration; Figure 2b shows the subsea system of Figure 2a with the flexible joint in a second configuration, at a flex angle of 15° from well centre; Figure 3a shows a simplified schematic cross-sectional view of a flexible joint in accordance with the invention, the flexible joint in a resting configuration; Figure 3b shows the flexible joint of Figure 3a in a flexed configuration at 15° from well centre, with an example positioning of a wireline tool; Figure 4 shows a schematic view of an offshore assembly including a vessel (e.g. MODll, drilling rig, WIV etc.) with a deployed riser and subsea system; Figure 5 shows a schematic view of a slimline subsea system in accordance with the invention comprising hydraulic control lines; Figure 6 shows a cross-sectional view of the system of Figure 5; Figure 7 shows a schematic view of the subsea system of Figure 5 without the hydraulic control lines illustrated; Figure 8 shows the subsea system of Figure 7 with the flexible joint flexed to approximately 15°; Figure 9 shows a cross-sectional view of Figure 7; Figure 10 shows a cross-sectional view of Figure 8; Figure 11 shows a schematic view of an example lower marine riser package with surrounding protective framework; Figure 12 shows a cross-sectional view of the lower marine riser package of Figure 11 without the surrounding protective framework; Figure 13 shows a cross-sectional view of the lower marine riser package of Figure 11; Figure 14 shows a cross-sectional view of the lower marine riser package of Figure 12; Figure 15 shows a schematic view of an example connector in accordance with the invention, with surrounding protective framework; Figure 16 shows a schematic view of the connector of Figure 15 without the surrounding protective framework; Figure 17 shows a cross-sectional view of the connector of Figure 15; Figure 18 shows a cross-sectional view of the connector of Figure 16; Figure 19 shows a schematic view of a connector housing for use with the connector of Figures 15-18; Figure 20 shows a cross-sectional view of the connector housing of Figure 19; Figure 21 shows a schematic view of an accumulator bank and multiplex control system that can be connected to an emergency disconnect package; Figure 22 shows a schematic view of a prior art hydraulic coupling assembly; and Figure 23 shows a schematic view of a hydraulic coupling assembly in accordance with the invention. DETAILED DESCRIPTION OF EXAMPLES OF THE INVENTION Figure 1 shows an example of a prior art subsea system 10 connected to a Christmas tree 15. Subsea system 10 comprises an emergency disconnect package (EDP) 40, a lower marine riser package (LMRP) 60, and a flexible joint 20. The LMRP 60 is disposed directly above the Christmas tree 15, with the EDP 40 connected to the LMRP 60. The flexible joint 20 is in turn connected to the EDP 40, above the EDP 40, and between the EDP 40 and the riser system (not illustrated). The flexible joint 20 can flex up to 15° from the vertical axis of the subsea system 10 (in other words, from well centre). Figure 2a shows a subsea system 110 in accordance with the present invention. Subsea system 110 comprises an EDP 140, LMRP 160, and a flexible joint 120. In contrast to the prior art system 10, the flex joint 120 of the present invention is connected between the EDP 140 and the LMRP 160. As before, the flexible joint 120 can flex up to 15° from well centre as illustrated in Figure 2b. Figure 3a shows a simple view of a flexible joint 220 comprising an internal chamber 222 forming part of the bore 222 of the flexible joint 220. The chamber 222 comprises a widened section of the bore 222 having a greater internal diameter than the rest of the bore 222. As shown in Figure 3b, when the flexible joint 220 flexes, the increased internal diameter of the chamber 222 means that a wireline tool 226 can still be comfortably retained within or passed through the flexible joint 220. Figure 4 shows an example of an offshore assembly 300 where a slimline version of a subsea system 310 is deployed from a MODU 350 or similar vessel (hereafter the general term vessel will be used). The subsea system 310 is configured to connect at its lower end to a Christmas tree, and at its upper end to a riser that extends between the subsea system 310 and the vessel 350. Figures 5 and 6 show a further example of a subsea system 410. In this example, the subsea system 410 is configured so that the entire envelope of the system - i.e. the external diameter - is less than 49.5” (approximately 126 cm). The subsea system 410 comprises an EDP 440, an LMRP 460, and a flexible joint 420. The flexible joint 420 is disposed between the EDP 440 and the LMRP 460. Control line bundles 411 are connected around the lower end of the EDP 440. The lower end of the LMRP 460 comprises a connector 470 and connector housing 475, which will be discussed further in relation to Figures 15-20. The connector 470 and / or the connector housing 475 are fixed to a Christmas tree guide 480. Figures 7-10 show the subsea system 410 without the connector housing 475 and the associated Christmas tree guide 480 that was illustrated in Figures 5 and 6. The EDP 440 comprises a protective framework 441 that surrounds and protects the module. At the upper end of the EDP, there is a bank of accumulators 444 which can be used with a multiplex control system where the deployment is in deeper water. Alternatively, the accumulators 444 can be removed if, for example, the subsea system 410 is to be deployed in more shallow water. The flexible joint 420 comprises a housing 421. As best seen in Figures 9 and 10, within the flexible joint 420 there is chamber 425 which has a larger inner diameter to allow passage of wireline tools when the flexible joint 420 is flexed at an angle. Extending between the lower end of the chamber 425, and the upper end of the LMRP 460 is a cylindrical linkage 426. The cylindrical linkage 426 comprises a bore 428, and at the lower end of the linkage 426 there is an arcuate rim or shoulder 427 that extends at least partially around the outside of the linkage 426. Within the LMRP 460 there is a corresponding arc-shaped recess 467. As best seen in Figure 10, when the subsea system 410 flexes, the linkage 426 is pulled up into the recess 467. The mutually arcuate shapes of the shoulder 427 and the recess 467 allow the linkage 426 to roll within the recess 467 and lets the EDP 440 rotate with the flexible joint 420. The EDP 440 and the LMRP 460 are surrounded by a protective framework 441, 461 to protect the respective modules both during deployment and while installed. The lower end of the subsea assembly 410 is shown in Figures 11-14, with the connector 470, LMRP 460, and flexible joint 420 illustrated, and a closer view of the lower end of the LMRP 460 and connector 470 is shown in Figures 15-18. As best seen in Figures 15 and 16, the hydraulic conduit 468 extends through the LMRP 460 to the connector 470. The conduit 468 passes through the control panel 469 of the LMRP. The hydraulic conduit 468 is arranged to traverse the LMRP 460 (and the upper modules of the subsea system 410 such as the flexible joint 420 and the EDP 440) as closely as possible, with no projecting connections. This allows the subsea system 410 to have a small envelope of under 49.5” (approx. 126 cm), in contrast to other systems. Configuring the subsea system 410 with a small envelope allows for the passage of the system through the rotary table of the vessel. The protective framework 461 is connected at its lower end to a bracket 462. The hydraulic conduit 468 is also configured to pass through the bracket 462. The LMRP 460 and the connector 470 are fluidly connected by a bore 470a that extends between them. Figures 19 and 20 show the connector housing 475, pin housing 472, and pins 473. The pins 473 project from the inner surface of the connector housing 475 and are resiliently biased towards the connector 470 (e.g. with coil springs or similar). The resiliently biased pins 473 retract as the connector housing 475 is installed over the connector 470 until they are aligned with the slot 471 in the connector 470. When the pins 473 align with the slot 471 they extend into the slot 471 due to the biasing force of the spring within the pin housing 472. The connector 470 and connector housing 475 together allow the guide frame 480 for the BOP connection to be aligned without requiring any further framework or components, again reducing the overall envelope of the subsea system 410. Figure 21 shows an example of a bank of accumulators 544 positioned above the EDP 540 and connected to a multiplex control 545. Positioning the bank of accumulators 544 above the EDP 540 can further reduce the envelope of the subsea system, where accumulators 544 and multiplex control 545 are required. Figure 22 shows the usual means of connecting a hydraulic conduit with hydraulic coupling 690 mounted on plates that project beyond the external diameter of the system. For example, in Figure 22, the coupling 690 extends between a plate projecting outboard from a connector 691 and a plate extending from a mandrel 692. Figure 23 shows a hydraulic coupling 790 in accordance with the present invention. The coupling 790 is arranged to be inboard of the connector 791 and the mandrel 792, with an end of the coupling 790 disposed within a recess 793 in the mandrel’s 792 outer surface. This rearrangement and redesign of the hydraulic coupling 790 reduces the external dimensions of the system at this location and contributes to the envelope of the subsea system of the invention being reduced. Modifications and improvements may be made to the examples and embodiments hereinbefore described without departing from the scope of the invention.

Claims

1. A subsea system comprising a lower marine riser package, emergency disconnect package, and a flexible joint, wherein the flexible joint is disposed below the emergency disconnect package and on or in the lower marine riser package.

2. A subsea system as claimed in claim 1, wherein the flexible joint comprises an internal bore having a diameter of at least 13 5 / 8” (approx. 35cm).

3. A subsea system as claimed in claim 1 or claim 2, wherein the flexible joint is configured to remain connected to the lower marine riser package when the EDP is retrieved.

4. A method of installing a subsea system comprising the steps of:providing an emergency disconnect package, a flexible joint, and a lower marine riser package;connecting the emergency disconnect package to the flexible joint, and the flexible joint to the lower marine riser package;connecting the lower marine riser package to a Christmas tree installed on a wellhead.

5. A method as claimed in claim 4, wherein the method comprises disconnecting at least a portion of the subsea system.

6. A method as claimed in claim 4 or claim 5, wherein the method comprises activating the emergency disconnect package.

7. A method as claimed in claim 6, wherein the method comprises disconnecting the emergency disconnect package from the flexible joint.

8. A method as claimed in claim 7, wherein the flexible joint remains connected to the lower marine riser package after disconnection of the emergency disconnect package.

9. A method as claimed in claims 4-8, wherein the subsea system comprises a hydraulic connector, and wherein the method comprises connecting the lower marine riser package to the hydraulic connector.

10. A method as claimed in claim 9, wherein the method comprises subsequently connecting the hydraulic connector to the Christmas tree.

11. A subsea system comprising:a frame;a lower marine riser package;an emergency disconnect package; anda flexible joint disposed between the lower marine riser package and the emergency disconnect package;wherein the frame is configured to at least partially surround the lower marine riser package, emergency disconnect package, and flexible joint; andwherein the subsea system is adapted to be lowered through a rotary table of an offshore oil and / or gas vessel during deployment.

12. A subsea system as claimed in claim 11, wherein the subsea system is configured to be less than 49.5 inches (approximately 126cm) in external diameter.

13. A subsea system as claimed in claim 11 or claim 12, wherein the lower marine riser package comprises at least one ball valve.

14. A subsea system as claimed in claim 13, wherein the at least one ball valve comprises at least one cutting edge.

15. A subsea system as claimed in claims 11-14, wherein the subsea system comprises at least one hydraulic connector, wherein the hydraulic connector is configured to connect to a Christmas tree.

16. A subsea system as claimed in claim 15, wherein the hydraulic connector comprises at least one groove that extends at least partly around an outer surface of the hydraulic connector.

17. A subsea system as claimed in claim 16, wherein the subsea system comprises a guide, wherein the guide comprises a cylindrical portion configured to at least partially fit over the hydraulic connector.

18. A subsea system as claimed in claim 17, wherein the guide comprises at least one pin extending from an internal surface of the cylindrical portion of the guide.

19. A subsea system as claimed in claim 18, wherein the at least one pin is configured to fit within the groove.

20. A subsea system as claimed in claims 11-19, wherein the subsea system comprises at least one accumulator, wherein the at least one accumulator is disposed above the emergency disconnect package.

21. A subsea system as claimed in claim 20, wherein the at least one accumulator is coupled to a hydraulic system via at least one hydraulic coupling, wherein the at least one hydraulic coupling is disposed below the hydraulic connector.

22. A subsea system as claimed in claim 21, wherein the at least one hydraulic coupling is positioned between the hydraulic connector and a mandrel; and wherein the hydraulic coupling is positioned radially inward of the external surface / diameter of the hydraulic connector and / or mandrel.

23. A method of installing a subsea system comprising:connecting an emergency disconnect package (EDP), a flexible joint, and a lower marine riser package (LMRP) above a rotary table of an offshore oil and / or gas vessel;picking up the subsea system; andlowering the subsea system through the rotary table.

24. A method as claimed in claim 23, the method comprises assembling the subsea system such that the external diameter of the subsea system does not exceed 49.5” (approx. 126 cm).

25. A method as claimed in claim 24, wherein the method comprises connecting hydraulic conduits via at least one hydraulic coupling that is disposed within the 49.5” (-126 cm) envelope of the subsea system.

526. A method as claimed in claim 24 or claim 25, wherein the method comprises positioning at least one accumulator within the 49.5” (-126 cm) envelope of the subsea system.10 27. A method as claimed in claims 23-26, wherein the method comprises:connecting the LMRP to a hydraulic connector, wherein the hydraulic connector comprises a slot track on an external surface; andmounting a connector housing on the hydraulic connector, wherein the connector housing at least partially surrounds the hydraulic connector, and the connector 15 housing comprises at least one pin configured to project from an internal surface of the connector housing and resiliently biased towards the hydraulic connector;wherein the method comprises mounting the connector housing by aligning the at least one pin with the slot.A

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