WO2016083218A1

WO2016083218A1 - Subsea coupling arrangement

Info

Publication number: WO2016083218A1
Application number: PCT/EP2015/077018
Authority: WO
Inventors: Steinar Lindemann HESTETUN
Original assignee: Vetco Gray Scandinavia As
Priority date: 2014-11-24
Filing date: 2015-11-18
Publication date: 2016-06-02
Also published as: BR112017009939B1; NO20141418A1; NO338441B1; BR112017009939A2

Abstract

A subsea coupling arrangement (1) for connecting an end section (2) of a flexible conduit to a structural element (3), comprising: - an end fitting (6) mounted to the end section; - clamping elements (9) for clamping together a coupling member (7) of the end fitting and a coupling member (8) of the structural element; - a locking and release mechanism (12) which is manoeuvrable from a locking position, in which the coupling members are prevented from being disengaged from each other, to a releasing position, in which the coupling members are allowed to be disengaged from each other; and - at least one elongated pulling member (13a) which is configured to exert a pulling force on the locking and release mechanism and thereby strive to manoeuvre it from the locking position to the releasing position when the flexible conduit is subjected to an external force that causes a stretching of the end section.

Description

SUBSEA COUPLING ARRANGEMENT

FIELD OF THE INVENTION AND PRIOR ART

The present invention relates to a subsea coupling arrangement according to the preamble of claim 1 to be used for connecting an end section of a flexible conduit to a structural element of a subsea installation.

It is previously known to use a collet connector or clamp connector of conventional type for connecting an end section of a flexible conduit to a structural element of a subsea installation. If the flexible conduit is subjected to an external force that causes a stretching of the end section of the flexible conduit, the connector and/or the flexible conduit and/or the structural element might be damaged under the effect of tensile forces in the flexible conduit.

BRIEF DESCRIPTION

The object of the present invention is to provide a solution to the above-mentioned problem.

According to the invention, this object is achieved by a subsea coupling arrangement having the features defined in claim 1.

The subsea coupling arrangement of the present invention comprises: an end fitting which is mounted to an end section of a flexible conduit and which is provided with a coupling member configured for engagement with a corresponding coupling member of a structural element of a subsea installation; clamping elements which are configured to clamp together the coupling member of the end fitting and the coupling member of the structural element; a locking and release mechanism which is manoeuvrable from a locking position, in which the locking and release mechanism keeps the clamping elements clamped to said coupling members and thereby prevents the coupling members from being disengaged from each other, to a releasing position, in which the locking and release mechanism sets the clamping elements free for movement in relation to said coupling members and thereby allows the coupling member of the end fitting to be disengaged from the coupling member of the structural element; and at least one elongated pulling member, which is connected to a first attachment fixed to the locking and release mechanism and to a second attachment fixed at a distance from the end fitting at a position along the end section of the flexible conduit and which is configured to exert a pulling force on the locking and release mechanism and thereby strive to manoeuvre the locking and release mechanism from the locking position to the releasing position when the flexible conduit is subjected to an external force that causes a stretching of said end section.

When the pulling force exerted by the pulling member or pulling members on the locking and release mechanism is sufficiently strong, the locking and release mechanism is made to assume the releasing position and the coupling member of the end fitting may thereby be released from the coupling member of the structural element. Hereby, damages to the flexible conduit and the clamping elements due to tensile forces in the flexible conduit may be avoided.

Further advantages as well as advantageous features of the subsea coupling arrangement of the present invention will appear from the following description and the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

With reference to the appended drawings, a specific description of preferred embodiments of the invention cited as examples follows below. In the drawings:

Fig 1 is a perspective view of an end section of a flexible conduit connected to a structural element of a subsea installation by means of a subsea coupling arrangement according to a first embodiment of the present invention, as seen before the pulling members have been fixed to the locking and release mechanism,

Fig 2 is a lateral view corresponding to Fig 1 , Fig 3 is a perspective view of the components shown in Fig 1, as seen when the pulling members have been fixed to the locking and release mechanism,

Fig 4 is a lateral view corresponding to Fig 3,

Fig 5 is a perspective view corresponding to Fig 3, but from another direction, Fig 6 is a longitudinal section through the components shown in Fig 3,

Fig 7 is a detail enlargement according to the circle VII in Fig 6,

Fig 8 is a perspective view of the components shown in Fig 3, as seen when the locking and release mechanism has assumed the releasing position and the flexible conduit has been disconnected from the structural element, Fig 9 is a lateral view corresponding to Fig 8, and

Fig 10 is a perspective view of an end section of a flexible conduit connected to a structural element of a subsea installation by means of a subsea coupling arrangement according to a second embodiment of the invention, as seen before the pulling members have been fixed to the alternative locking and release mechanism. DETAILED DESCRIPTION

Subsea coupling arrangements 1 according to two different embodiments of the present invention are illustrated in Figs 1-9 and Fig 10, respectively. The coupling arrangement 1 is used for connecting an end section 2 of a flexible conduit to a structural element 3 of a subsea installation 4. In the illustrated example, the flexible conduit is a subsea flowline, whereas said structural element 3 is a valve housing of a valve included in a subsea installation 4 in the form of a flowline termination arrangement.

The coupling arrangement 1 comprises an end fitting 6, which is fixed to the end section 2 of the flexible conduit and which is provided with a coupling member 7 (see Figs 6 and 7) configured for engagement with a corresponding coupling member 8 of the structural element 3. The coupling arrangement 1 also comprises clamping elements 9, 9' which are configured to clamp together the coupling member 7 of the end fitting 6 and the coupling member 8 of the structural element 3. Each clamping element 9, 9' has opposed bevelled wedging surfaces 10a, 10b (see Fig 7) for engaging corresponding bevelled wedging surfaces 11a, 1 lb provided on the coupling members 7, 8 to be engaged with each other. In the embodiment illustrated in Figs 1- 9, the clamping elements 9 have the form of latching fingers which are distributed in the circumferential direction of the coupling members 7, 8. In the embodiment illustrated in Fig 10, the clamping elements 9' are arc-shaped and distributed in the circumferential direction of the coupling members 7, 8, wherein the clamping elements 9' are connected to each other at their ends.

Furthermore, the coupling arrangement 1 comprises a locking and release mechanism 12 which is manoeuvrable from a locking position (see Figs 3-7 and 10), in which the locking and release mechanism 12 keeps the clamping elements 9, 9' clamped to the coupling members 7, 8 and thereby prevents the coupling member 7 of the end fitting 6 from being disengaged from the coupling member 8 of the structural element 3, to a releasing position (see Figs 8 and 9), in which the locking and release mechanism 12 sets the clamping elements 9, 9' free for movement in relation to said coupling members 7, 8 and thereby allows the coupling member 7 of the end fitting 6 to be disengaged from the coupling member 8 of the structural element 3. The coupling arrangement 1 comprises at least one elongated pulling member 13 a, 13b, preferably in the form of a non-elastic wire or belt, which is configured to exert a pulling force on the locking and release mechanism 12 and thereby strive to manoeuvre the locking and release mechanism 12 from the locking position to the releasing position when the flexible conduit is subjected to an external force that causes a stretching of the end section 2 thereof. The locking and release mechanism 12 will pass from the locking position to the releasing position when the pulling force exerted on the locking and release mechanism 12 by the pulling member or pulling members 13a, 13b exceeds a force striving to keep the locking and release mechanism 12 in the locking position. Each pulling member 13a, 13b is configured to be connected to and extend between a first attachment 14a, 14b fixed to the locking and release mechanism 12 and a second attachment 15 a, 15b fixed at a distance from the end fitting 6 at a position along the end section 2 of the flexible conduit. In the illustrated embodiments, the coupling arrangement 1 comprises two such pulling members 13a, 13b in the form of wires arranged on opposite sides of the end section 2 of the flexible conduit, wherein each pulling member 13a, 13b has a first end 16 fixed to the associated first attachment 14a, 14b and an opposite second end 17 fixed to the associated second attachment 15a, 15b.

In the illustrated embodiments, a bend restricting element 18 is fixed to the end fitting 6 and extends along the end section 2 of the flexible conduit in order to reduce the flexibility of this end section, wherein said second attachments 15a, 15b are fixed to the bend restricting element 18 on opposite sides thereof.

In the embodiment illustrated in Figs 1-9, the locking and release mechanism 12 comprises a sleeve-shaped locking member 19 which is configured to surround the clamping elements 9 and thereby keep the clamping elements clamped to the coupling members 7, 8 when the locking and release mechanism 12 is in the locking position. The clamping elements 9 and the sleeve-shaped locking member 19 form a collet connector. In the illustrated example, the above-mentioned first attachments 14a, 14b are fixed to a flange 20 of the sleeve-shaped locking member 19 and the sleeve- shaped locking member 19 is axially moveable in relation to the clamping elements 9 and configured to move axially from an advanced position (illustrated in Figs 3-7) to a retracted position (illustrated in Figs 8 and 9) when the locking and release mechanism 12 is manoeuvred from the locking position to the releasing position. When the sleeve-shaped locking member 19 is in the advanced position, an inner annular projection 21 at the front end of the locking member 19 abuts against an outer projection 22 at the front end of each clamping element 9 and the clamping elements 9 are thereby clamped to the coupling members 7, 8, as illustrated in Fig 7, and prevented from moving in the radial direction in relation to the coupling members 7, 8. When the sleeve-shaped locking member 19 is in the retracted position, said annular projection 21 is received in a recess 23 at the center part of each clamping element 9 and the front end of the clamping elements 9 are thereby allowed to move in the radial direction in relation to the coupling member 8 of the structural element 3, which makes it possible for the clamping elements 9 and the coupling member 7 of the end fitting 6 to be released from the coupling member 8 of the structural element 3 by an axial movement away from the last-mentioned coupling member 8. The locking and release mechanism 12 may comprises a shear pin 24 for retaining the sleeve- shaped locking member 19 in the advanced position, as illustrated in Fig 7, wherein the shear pin 24 is configured to break and thereby set the sleeve-shaped locking member 19 free for movement from the advanced position to the retracted position when the sleeve-shaped locking member 19 is subjected to a pulling force exceeding a given threshold value. An upper part of the shear pin 24 is received in a hole 25 provided in the sleeve-shaped locking member 19 and a lower part of the shear pin 24 is received in a hole 26 provided in one of the clamping elements 9. The locking and release mechanism 12 may as an alternative lack a shear pin, in which case the sleeve- shaped locking member 19 is retained in the advanced position under the effect of factional forces between the locking member 19 and the clamping elements 9.

As a further alternative (not shown), the sleeve-shaped locking member 19 may have the form of a split sleeve formed by two or more interconnected split sleeve portions which are configured to be separated from each other when the locking and release mechanism is manoeuvred from the locking position to the releasing position. In this case, the locking and release mechanism may comprise a locking pin which is configured to keep two split sleeve portions of the sleeve-shaped locking member in engagement with each other, wherein the locking pin is to be axially displaced under the effect of a pulling force exerted by a pulling member 13 a, 13b in order to disengage said two split sleeve portions from each other when the locking pin is subjected to a pulling force exceeding a given threshold value.

In the embodiment illustrated in Fig 10, the locking and release mechanism 12 comprises two elongated locking elements 19' in the form of trunnions, each of which extending through an axial bore in a clamping element 9' and through holes in two holding plates 27a, 27b which are arranged on opposite sides of two adjacent clamping elements 9' in order to keep the clamping elements connected to each other and clamped to the coupling members of the end fitting 6 and the structural element 3. The elongated locking elements 19' are configured to be axially displaced out of the bores in the clamping elements 9' in order to release the clamping elements 9' from each other when the locking and release mechanism 12 is manoeuvred from the locking position to the releasing position. In the illustrated example, the above- mentioned first attachments 14a, 14b are provided at an end of a respective locking element 19'. The clamping elements 9', the holding plates 27a, 27b and the elongated locking members 19' form a clamp connector.

In the illustrated embodiments, the first end 16 of each elongated pulling member 13a, 13b is detachably fixed to the associated first attachment 14a, 14b. In the embodiment illustrated in Figs 1-9, an end section of the respective pulling member 13a, 13b is insertable laterally into a recess 28 of the associated first attachment 14a, 14b and a stop member 29 is provided at the first end 16 of the pulling member 13a, 13b in order to prevent the pulling member from sliding axially out of said recess 28. During installation, before the pulling members 13 a, 13b have been fixed to the first attachments 14a, 14b, the first end 16 of the respective pulling member 13a, 13b may be temporarily secured to a holder 30 provided at the rear end of the end fitting 6, as illustrated in Figs 1, 2 and 10.

In the illustrated embodiments, the end section 2 of the flexible conduit and the bend restricting element 18 are arranged in an S-curved configuration when each pulling member 13 a, 13b is fixed to the associated first attachment 14a, 14b and extends rectilinearly between the first and second attachments 14a, 15a; 14b, 15b. Thus, each pulling member 13 a, 13b is shorter than the distance along the end fitting 6 and the end section 2 between the associated first and second attachments 14a, 15a; 14b, 15b. When the flexible conduit is subjected to an external force that causes a stretching of the end section 2 of the flexible conduit and the bend restricting element 18 so that these are straightened out, the pulling members 13 a, 13b will pull the locking member 19 from the advanced position illustrated in Figs 3-7 to the retracted position illustrated in Figs 8 and 9 and the coupling member 7 of the end fitting 6 may thereby be disengaged from the coupling member 8 of the structural element 3, as illustrated in Figs 8 and 9.

The invention is of course not in any way restricted to the embodiments described above. On the contrary, many possibilities to modifications thereof will be apparent to a person with ordinary skill in the art without departing from the basic idea of the invention such as defined in the appended claims.

Claims

CLAIMS:

1. A subsea coupling arrangement for connecting an end section (2) of a flexible conduit to a structural element (3) of a subsea installation, the coupling arrangement

(1) comprising: an end fitting (6) which is mounted to the end section (2) of the flexible conduit and which is provided with a coupling member (7) configured for engagement with a corresponding coupling member (8) of said structural element (3); clamping elements (9; 9') which are configured to clamp together the coupling member (7) of the end fitting (6) and the coupling member (8) of the structural element (3); and a locking and release mechanism (12) which is manoeuvrable from a locking position, in which the locking and release mechanism (12) keeps the clamping elements (9; 9') clamped to said coupling members (7, 8) and thereby prevents the coupling members from being disengaged from each other, to a releasing position, in which the locking and release mechanism (12) sets the clamping elements (9; 9') free for movement in relation to said coupling members (7, 8) and thereby allows the coupling member (7) of the end fitting (6) to be disengaged from the coupling member (8) of the structural element (3), characterized in that the coupling arrangement (1) comprises at least one elongated pulling member (13a, 13b), which is connected to a first attachment (14a, 14b) fixed to the locking and release mechanism (12) and to a second attachment (15a, 15b) fixed at a distance from the end fitting (6) at a position along the end section (2) of the flexible conduit and which is configured to exert a pulling force on the locking and release mechanism (12) and thereby strive to manoeuvre the locking and release mechanism (12) from the locking position to the releasing position when the flexible conduit is subjected to an external force that causes a stretching of said end section

(2) ·

2. A subsea coupling arrangement according to claim 1 , characterized in: that the coupling arrangement (1) comprises a bend restricting element (18), which is fixed to the end fitting (6) and extends along the end section (2) of the flexible conduit in order to reduce the flexibility of this end section (2); and that said second attachment (15a, 15b) is fixed to the bend restricting element

(18).

3. A subsea coupling arrangement according to claim 1 or 2, characterized in that said at least one elongated pulling member (13a, 13b) has the form of a wire or belt.

4. A subsea coupling arrangement according to claim 3, characterized in that said at least one elongated pulling member (13a, 13b) has a first end (16) fixed to the first attachment (14a, 14b) and an opposite second end (17) fixed to the second attachment (15a, 15b).

5. A subsea coupling arrangement according to any of claims 1-4, characterized in that the coupling arrangement (1) comprises at least two such pulling members (13a, 13b) arranged on opposite sides of the end section (2) of the flexible conduit.

6. A subsea coupling arrangement according to any of claims 1-5, characterized in that the locking and release mechanism (12) comprises a sleeve-shaped locking member (19) which is configured to surround the clamping elements (9) and thereby keep the clamping elements clamped to said coupling members (7, 8) when the locking and release mechanism (12) is in the locking position.

7. A subsea coupling arrangement according to claim 6, characterized in: that said first attachment (14a, 14b) is fixed to the sleeve-shaped locking member (19); and that the sleeve-shaped locking member (19) is axially moveable in relation to the clamping elements (9) and configured to move axially from an advanced position to a retracted position when the locking and release mechanism (12) is manoeuvred from the locking position to the releasing position.

8. A subsea coupling arrangement according to claim 7, characterized in that the locking and release mechanism (12) comprises a shear pin (24) for retaining the sleeve-shaped locking member (19) in said advanced position, the shear pin (24) being configured to break and thereby set the sleeve-shaped locking member (19) free for movement from said advanced position to said retracted position when the sleeve- shaped locking member (19) is subjected to a pulling force exceeding a given threshold value.

9. A subsea coupling arrangement according to any of claims 6-8, characterized in that the clamping elements (9) have the form of latching fingers.

10. A subsea coupling arrangement according to any of claims 1-5, characterized in that the clamping elements (9') are arc-shaped and distributed in the circumferential direction of said coupling members (7, 8).