A method of testing installation of a module on an elongate member

Abstract

The invention provides a method of testing installation of a module (10) on an elongate member (12). The module comprises at least two module parts (14, 16) configured to be assembled to one another around the elongate member (12), together forming a through-going passage (21) for receiving the elongate member (12). The module (10) further comprises at least one resiliently deformable seat (30, 32) within the through-going passage (21) for seating upon the elongate member (10) and an arrangement for securing the module parts to one another, which may take the form of straps (24, 26). The module has a channel (34) extending from an outer surface (17) of the module to the through-going passage (21), so that after assembly of the module parts (14, 16) about the elongate member (12) and securing of them to one another, a test rod or testing tool (36) can be inserted into the channel until it contacts the elongate member (12) within the through-going passage (21), and can be used to determine whether the deformable seats (30, 32) have been sufficiently compressed.

Description

[0001] A METHOD OF TESTING INSTALLATION OF A MODULE ON AN ELONGATE MEMBER

[0002] The invention is concerned with modules carried on elongate members such as risers, pipelines, hoses, cables and umbilicals, and in particular with a means of determining whether such a module has been properly installed.

[0003] The module in question may be for deployment underwater, and may in particular be a buoyancy module. The scope of the invention is not limited to buoyancy modules as such - it could be applied, for example to ballast modules, or to sensor modules - and while much of the discussion below relates to buoyancy as such, this broader potential scope of the invention should be borne in mind.

[0004] It is known to form so-called distributed buoyancy modules, intended for mounting on some form of underwater elongate member, in two parts which are to be assembled to one another about the elongate member. Typically, the module parts are generally semi- cylindrical, each having a mating face which will abut or adjoin the mating face of the other part in the assembled module. Each mating face has a recess, running along the length of the module part, and in the assembled module the two recesses align to form a through-passage in which the elongate member is received. The two module parts are typically secured to one another by means of one or more straps passed around the module parts and secured under tension. Other means of securing the module parts to one another are possible. For example, they may be configured to be bolted to one another.

[0005] Underwater buoyancy modules are commonly formed from syntactic foam - a composite comprising a polymer matrix material incorporating density-reducing elements such as hollow macrospheres and / or smaller microspheres.

[0006] Some means is typically needed to prevent the module from moving along the elongate member. In some cases this is done by means of clamps. An alternative is to have the module parts themselves rest upon the elongate member through some form of seat or saddle which is urged against the elongate member, providing the friction needed to resist slippage of the module along it. Pressure urging the seat or saddle into engagement with the elongate member is thus provided by the means used to secure the two parts of the module together. To maintain this pressure despite variable factors such as material creep through a prolonged design lifetime, the seat or saddle may be compliant, so that is loaded (typically, compressed) as the two parts of the module are secured together. In such an arrangement, it is important to ensure that the seat or saddle is stressed to the required degree during installation, failing which the module might (at the outset, or at some point in its design lifetime) prove to be able to move along the elongate member, which could cause failure. One precaution that can be taken in that respect is to measure a load applied to the means used to secure the parts of the module together. For example, where that means is a strap, the tension applied to the strap can be measured. In the case of bolts, torque could be measured. But errors remain possible. For example, the installation tool used to measure the tension, torque etc. may malfunction. Some form of check is thus desirable, to ensure that the module's seat or saddle has been suitably stressed during installation.

[0007] According to a first aspect of the present invention, there is a method of testing installation of a module on an elongate member, wherein the module comprises at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, and an arrangement for securing the module parts to one another, the module comprising a channel extending from an outer surface of the module to the through-going passage, and the method comprising: assembling the module parts about the elongate member and securing them to one another using the said arrangement; inserting a test rod into the channel until an end of the test rod contacts the elongate member within the through-going passage, and determining whether depth of insertion of the test rod is consistent with proper installation of the module.

[0008] According to a second aspect of the present invention, there is a module for installation on an elongate member, the module comprising at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, and a channel extending from an outer surface of the module to the channel being arranged such that a test rod inserted into the channel is able to contact the elongate member within the module.

[0009] According to a third aspect of the present invention there is a method of testing installation of a module on an elongate member, wherein the module comprises: at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, an arrangement for securing the module parts to one another, and a channel extending from an outer surface of the module to the through-going passage, and the wherein method comprises: assembling the module parts about the elongate member and securing them to one another using the said arrangement, causing the resiliently deformable seat to be compressed, and inserting a testing tool through the channel and using the testing tool to determine a separation between the elongate member and the module.

[0010] According to a fourth aspect of the present invention there is a testing tool for testing installation of a module on an elongate member, the testing tool comprising: an elongate tool body having a proximal end and a distal end, a test rod mounted to the tool body for movement along the tool body, the test rod being able to protrude beyond the distal end of the tool body, and being visible at least in the region of the proximal end of the tool body, an engagement part at or adjacent the distal end of the tool body for engaging an interior surface of the module to register the tool body therewith, and a marker, scale or other visible feature on the test rod which is visually observable to determine in use whether the position of the test rod with respect to the tool body is indicative of proper installation of the module on the elongate member.

[0011] According to a fifth aspect of the present invention there is a testing tool for testing installation on an elongate member of a module, the module comprising: at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, the through-going passage having an interior surface, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, an arrangement for securing the module parts to one another, and a channel extending from an outer surface of the module to the through-going passage, the testing tool comprising: an elongate tool body insertable in the channel and having a proximal end and a distal end, an engagement part at or adjacent the distal end of the tool body for engaging the interior surface of the module, and a distance sensor for determining a distance between the sensor and the elongate member, to determine whether the deformable seat has been adequately compressed against the elongate member.

[0012] A specific embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which:-

[0013] Figure 1 is a view along a radial direction of a buoyancy module embodying the present invention, mounted on an elongate member;

[0014] Figure 2 depicts one module part of the buoyancy module, viewed along the radial direction, along with the elongate member;

[0015] Figures 3a and 3b are enlargements of part of Figure 2, showing two different conditions of a test rod being employed in accordance with a first embodiment of the present invention;

[0016] Figure 4 depicts a testing tool according to a second embodiment of the present invention;

[0017] Figure 5 depicts the testing tool in use in relation to a buoyancy module mounted on an elongate member;

[0018] Figure 6 is an enlarged view of a proximal end of the testing tool where it emerges from the buoyancy member; and

[0019] Figures 7a - 7d depict in simplified form successive stages in the use of a testing tool according to a third embodiment of the present invention.

[0020] The module 10 depicted in the drawings is a buoyancy module carried upon an elongate member 12 which in this example is a steel riser to be deployed beneath the sea, but as noted already the invention may be implemented in relation to modules of other types including (without limitation) ballast modules and sensor modules, and the elongate member may take a variety of different forms including (without limitation) risers of other materials, hoses, cables, including electrical cables and fibre-optic cables, umbilicals and pipelines.

[0021] The module 10 comprises, in this example, first and second module parts 14, 16. In other embodiments the module 10 could comprise three or more such parts. Both of the module parts 14, 16 are generally semi-cylindrical, so that the module 10 formed by them has an outer surface 17 which is generally a cylinder, although it may take other shapes in other embodiments. As seen in Figure 2, the first module part 14 has a mating face 18, which in the present embodiment is generally flat and lies in an axial plane. In the mating face is a trench 20, which is of semi-circular cross section and extends from one end 22 of the module part 14 to its other end 23. The second module part 16 is similarly formed in this respect, so that in the assembled module 10 the trenches 20 together form a through-going passage 21 which receives the elongate member.

[0022] The module parts 14, 16 are in the present embodiment secured to one another through two straps 24, 26 passed circumferentially about the module 10 and secured under tension.

[0023] The module 10 is configured to seat upon the elongate member 12 through seats 30, 32. In the present embodiment these are annular and each is formed by two "C" shaped parts, one carried on the first module part 14 and the other carried on the second module part 16. Many other formations of the seat are possible without departing from the scope of the present invention. In the assembled module 10, the seats 30, 32 contact the elongate member 12 under pressure. The seats 30, 32 are formed in such a way as to be resiliently deformable underthis pressure. In the present embodiment, they are solid resilient parts able to compress somewhat under pressure. The seats 30, 32 may comprise an elastomeric material. Other forms of resilient seat may however be adopted, e.g. using springs of any suitable type to achieve the requisite compliance.

[0024] When the module parts 14, 16 are assembled around the elongate member 12 and the straps 24, 26 are tensioned, a radial force is exerted on the seats 30, 32, causing them to compress somewhat. As this compression of the seats 30, 32 takes place, the mating faces 18 of the module parts 14, 16 move together and the radius of the module 10 reduces somewhat. The present invention provides a means of checking that the seats 30, 32 have compressed sufficiently. If they have, this implies that an adequate force has been applied by the straps 24, 26 and the installation has been properly carried out. For this purpose, the module 10 provides a channel 34 leading from the outer surface 17 of the module 10 to the through- going passage 21. In the present embodiment the channel 34 is substantially radial. The channel 34 may be formed through one of the module parts 12, 14 or it may be formed between them. In the present embodiment the channel 34 is formed by aligned semi-circular recesses in the respective mating faces 18 of the module parts 12, 14.

[0025] The channel 34 makes it possible in one embodiment to determine a distance from the elongate member 12 to the outer surface 17 of the module 10. In a first embodiment of the present invention represented in Figure 1 to 3, this is done using a test rod 36 inserted into the channel 34 until its end 38 contacts the elongate member 12. The depth of penetration of the test rod 36 is thus the distance from outer surface 40 of the elongate member 12 to the outer surface 17 of the module 10. The test rod 36 may carry a marker or markings used to establish whether this distance is in accordance with requirements. For example, appearance of a marker 42 on the test rod 36 above the outer surface 17 (as in Figure 3a) may serve as confirmation that the seats 30, 32 have been sufficiently compressed, and that the installation is acceptable. If the marker 42 is not visible above the outer surface 17, as in Figure 3b, then the test is failed, the seats 30, 32 have not been adequately compressed and investigation may be necessary. The marker 42 may take any visible form - an aspect of shape of the test rod, for example, or of its colouring. It may be an etched marking, a painted marking, a detente, an upstand, and so on.

[0026] It may not always be appropriate to take a measurement from the outer surface 17 of the module 10 to the elongate member 12. For example, it may be that the manufacturing tolerance in radial depth of the module 10 is large enough to render this mode of measurement inaccurate and unreliable. In the second embodiment of the invention depicted in Figures 4 to 6, a measurement is instead made of distance between an internal surface of the buoyancy module 10a and outer surface 40a of elongate member 12a. This measurement is made using a testing tool 50 comprising an elongate tool body 52 with a proximal end 54 and a distal end 56. In the present embodiment the tool body 52 comprises a tube. At or adjacent the distal end 56, the tool body 52 has an engagement part 58 for engaging an interior surface 60 of the buoyancy module 10a. The interior surface 60 is formed by the trench 20. In the present embodiment, the engagement part 58 comprises a lateral upstand (or in the illustrated example a pair of oppositely facing lateral upstands), disposed at the distal both its proximal and distal ends 54, 56, being rendered captive by a handle 64 at a proximal end of the test rod 36a and an enlarged contact foot 66 at the distal end of the test rod 36a. The test rod 36a is slidable along a limited distance with respect to the tool body 52.

[0027] In use, the tool body 52, including the engagement part 58, is inserted distal-end-first through the channel 34a and then moved laterally to engage the engagement part 58 with the interior surface 60. This serves to register the tool body 52 with the interior surface 60. The distal end of the test rod 36a (formed by the contact foot 66) is brought to rest against the elongate member 12a, as in Figure 5. The separation of the distal end of the test rod 36a from the engagement part 58 is thus representative of the separation between the outer surface 40a of the elongate member 12a and the interior surface 60 of the buoyancy module 10a. Proximal portions of the tool body 52 and the test rod 36a remain visible outside the buoyancy module 10a, and the projection of the test rod 36a beyond the proximal end of the tool body 52 provides an indication of that separation. A marker (not visible in the drawings) is provided on the test rod 36a to determine whether its projection beyond the proximal end 54 of the tool body corresponds to the desired separation. If the test rod 36a does not project far enough from the proximal end 54 of the tool body 52 for the marker to be revealed outside of the tool body 52 then the seats 30a, 32a have not been adequately compressed and the buoyancy module 10a has not been correctly fitted. Remedial action is then required.

[0028] In the embodiment of Figures 4 to 6, the engagement part 58 increases the lateral dimension of the tool body 52, and the channel 34a must be large enough to accommodate it. An alternative embodiment is schematically represented in Figures 7a to 7d, wherein the module is indicated at 10b and carries resilient seats 30a, 30b. In this embodiment the engagement part 58b is movable with respect to the tool body 52b between a stowed configuration in which its lateral extent is minimised and a deployed configuration in which it extends laterally to engage the inner face 60b of the buoyancy module 10b. More specifically, in this embodiment the engagement part 58b is pivotally connected to the tool body 52b. In the stowed configuration (Figure 7a) the engagement part 58b is aligned along the tool body 52 and hence contributes little or not at all to the width of the tool body 52. Hence the tool body 52 can be inserted through channel 34b in this configuration, meaning that the channel 34b need only be wide enough to accommodate the tool body 52b. After the tool body is inserted, the engagement part 58b is turned (as depicted in Figures 7b and 7c) to its deployed configuration in which it projects laterally from the tool body 52b. The tool body 52b is then withdrawn far enough to engage the engagement part 58b with interior surface 60b of the buoyancy module 10b, providing the required registration between the tool body 52 and the interior surface 60b.

[0029] In this embodiment, separation between the outer surface of the elongate member (which is omitted from Figure 7) and interior surface 60b of the buoyancy module 10b is measured using an electronic sensor carried on the tool body 52 and / or on the engagement part 58b. The sensor may comprise any suitable distance-sensing technology and may for example be a sonar distance sensor, a LiDAR sensor or a laser triangulation sensor. Sensor readings may be transmitted through any suitable means including a wired or optical connection through the tool body 52, or an RF link of any suitable form.

[0030] It will be appreciated that the aforegoing embodiments are presented by way of illustration and not of limitation. Any number of variants is possible without departing from the scope of the present invention. For example, the shape of the buoyancy module or of its constituent parts may differ in other embodiments, as may the number of parts into which the buoyancy module is divided. In the illustrated embodiments the seats are of small axial extent, but the invention imposes no particular limitation in that respect. For example, the seat could be formed by the entire internal area of the through-going passage 21, e.g. in a case where that area is covered by a compressible layer.

Claims

CLAIMS1. A method of testing installation of a module on an elongate member, wherein the module comprises: at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, an arrangement for securing the module parts to one another, and a channel extending from an outer surface of the module to the through-going passage, and wherein the method comprises: assembling the module parts about the elongate member and securing them to one another using the said arrangement, causing the resiliently deformable seat to be compressed; and inserting a testing tool through the channel and using the testing tool to determine a separation between the elongate member and the module.

2. A method as claimed in claim 1 in which the testing tool comprises a test rod and the method comprises inserting the test rod into the channel until an end of the test rod contacts the elongate member within the through-going passage, and determining whether depth of insertion of the test rod is consistent with proper installation of the module.

3. A method as claimed in claim 2 in which the test rod has a marker whose visibility above an outer surface of the module, when the test rod has been inserted until its end contacts the elongate member, indicates that the seat has been deformed sufficiently for proper installation of the module.

4. A method as claimed in claim 1 in which the testing tool comprises an elongate tool body having a proximal end and a distal end, a test rod which is mounted to the tool body for movement along the tool body and an engagement part at or adjacent the9distal end of the tool body for engaging an interior surface of the module to register the tool body therewith, the method further comprising: engaging the engagement part with the interior surface of the module after insertion of the testing tool into the channel; moving the test rod so that an end of the test rod contacts the elongate member, leaving the proximal end of the test rod visible at the module's exterior; and determining whether the position of the test rod with respect to the tool body is indicative of proper installation of the module.

5. A method as claimed in claim 4 in which the test rod carries a marker, the method further comprising observing whether said marker is visible to determine whether projection of the test rod from the proximal end of the tool body is sufficient to indicate proper installation of the buoyancy module.

6. A method as claimed in claim 4 or claim 5 in which the tool body is tubular and the test rod is received in the tool body and protrudes from its distal end.

7. A method as claimed in any preceding claim, further comprising deploying the module and the elongate member underwater.

8. A method as claimed in any preceding claim in which the module is a buoyancy module.

9. A testing tool for testing installation of a module on an elongate member, the testing tool comprising: an elongate tool body having a proximal end and a distal end, a test rod mounted to the tool body for movement along the tool body, the test rod being able to protrude beyond the distal end of the tool body, and being visible at least in the region of the proximal end of the tool body, an engagement part at or adjacent the distal end of the tool body for engaging an interior surface of the module to register the tool body therewith, anda marker, scale or other visible feature on the test rod which is visually observable to determine in use whether the position of the test rod with respect to the tool body is indicative of proper installation of the module on the elongate member.

10. A testing tool as claimed in claim 9 in which the tool body is tubular and the test rod is received in the tool body.

11. A testing tool as claimed in claim 9 or claim 10 in which the test rod has a proximal end which projects from the proximal end of the tool body and a distal end which projects from the distal end of the tool body, and carries at least one marker positioned to be hidden within the tool body when the test rod is in a first position with respect to the tool body and to be visible outside of the tool body when the test rod is in a second position with respect to the tool body.

12. A testing tool as claimed in any of claims 9 to 11 in which the engagement is movable between a deployed configuration in which it projects laterally from the tool body to engage the interior surface of the module, and a stowed configuration in which its lateral projection is reduced.

13. A testing tool as claimed in any of claims 9 to 12 in combination with a module configured to be mounted on an elongate member, the module comprising: at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, the through-going passage having an interior surface, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, an arrangement for securing the module parts to one another, and a channel extending from an outer surface of the module to the through-going passage, and the testing tool being insertable through the channel when the module is mounted on the elongate member, enabling the engagement part to be engaged withthe interior surface, and the test rod to be advanced to contact the elongate member, whereupon the position of the test rod with respect to the tool body indicates whether the deformable seat has been adequately compressed.

14. A module for installation on an elongate member, the module comprising at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, and a channel extending from an outer surface of the module to the channel being arranged such that a test rod inserted into the channel is able to contact the elongate member within the module.

15. A module as claimed in claim 14 which has a substantially circular cross-sectional shape, wherein the channel extends substantially radially.

16. A module as claimed in claim 14 or claim 15 provided with at least one strap for securing the two module parts to one another around the elongate member.

17. A kit of parts comprising a module as claimed in any of claims 14 to 16 and one of (a) a test rod insertable into the channel, and (b) a testing tool as claimed in any of claims 9 to 12.

18. A kit of parts comprising a module as claim in any of claims 14 to 16 and a test rod insertable in the channel, in which the test rod has a marker positioned so that when the test rod is inserted so that an end of the test rod contacts the elongate member within the through-passage, positioning of the marker above an outer surface of the module indicates that the deformable seat has been adequately compressed.

19. A testing tool for testing installation of a module on an elongate member of, the module comprising:12at least two module parts configured to be assembled to one another around the elongate member, together forming a through-going passage for receiving the elongate member, the through-going passage having an interior surface, at least one resiliently deformable seat within the through-going passage for seating upon the elongate member, an arrangement for securing the module parts to one another, and a channel extending from an outer surface of the module to the through- going passage, the testing tool comprising: an elongate tool body insertable in the channel and having a proximal end and a distal end, an engagement part at or adjacent the distal end of the tool body for engaging the interior surface of the module, and a distance sensor for determining a distance between the sensor and the elongate member, to determine whether the deformable seat has been adequately compressed against the elongate member.13

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