EP2207991B1 - Device for measuring the movement of a subsea deformable pipeline - Google Patents

Abstract

The device (14) has two receiving supports anchored in sea bottom (10) for receiving two deformable submarine flowlines. A divisible, visible and observable element assembly (26) has rods (28) for connecting one submarine flowline and one receiving support (18). The assembly is extended along a mean direction parallel to a determined path. The rods are successively separated by another submarine flowline (12) and another receiving support when the flowlines are driven in movement along the path to measure amplitude of the measurement of the flowlines according to the number of separated rods. An independent claim is also included for a method for measuring the movement of a deformable submarine flowline with respect to sea bottom.

Description

The invention relates to a device for measuring the movement of a deformable underwater pipe with respect to a seabed.

One area of application envisaged is that of the English-language flowline , which extends over the seabed. They are intended to connect a wellhead which, it, protrudes from the seabed, to a rising pipe which, from the seabed, extends catenary to reach a surface installation. The bottom pipe, which is supported on the seabed from the wellhead, has a connecting end for connecting the bottom pipe to the riser, or to another bottom pipe.

Also, a hydrocarbon flowing from the wellhead is returned to the surface installation via the bottom pipe and the riser pipe.

Other technical fields are envisaged, where a flexible pipe is likely to deform under the effect of thermal and / or mechanical variations of a fluid that passes through it.

The hydrocarbons flow from the wellhead at a pressure and a temperature which vary with time and moreover, when the flow is stopped, for any reason related to the operation, the conditions of pressure and temperature of the driving of bottom evolve brutally. As a result, the bottom pipe then expands or contracts when, for example, the flow resumes. A bottom pipe of a thousand meters for example, can undergo longitudinal dimensional variations of the order of one meter.

Thus, during the life of the oil field, which can reach a few years, the bottom pipe is subjected to numerous cycles of expansion and retraction with consequent amplitudes that induce significant efforts on the pipe and the connecting pieces.

It is known to minimize the forces imposed on the structure by designing structures capable of absorbing these efforts. For this, the ends of Connections are mounted on metal structures capable of sliding on a foundation anchored in the seabed. In this way, the connecting end can accommodate longitudinal displacements. However residual friction remains at the connection ends and it is important to evaluate these excursions to ensure that these efforts are compatible with the structure of the bottom pipe.

It is also possible to continuously monitor the behavior of the structure by recording data in real time. Thus one can follow in real time the elongation of the structure and determine if it is compatible with the values of elongation limit that the connecting pieces in particular, can support. But this requires an expensive, fragile device and a connection to the surface for the exploitation of the data.

UA 24,383 U describes such dispostif.

Also, a problem that arises and that aims to solve the present invention, is to provide a device that can measure and control the movements of a bottom deformable underwater pipe and at an advantageous cost.

In order to solve this problem, the present invention proposes a device for measuring the movement of a deformable underwater pipe with respect to a seabed, said deformable underwater pipe being extended on said seabed to transport fluids between two downhole installations, said deformable underwater pipe being capable of deforming as a function of the temperature of the fluids transported, said measuring device comprising a reception support anchored in said seabed between said installations for receiving said deformable underwater pipe . When it deforms, the deformable underwater pipe is likely to be driven in a determined path relative to the receiving support, said movement having an amplitude that varies as a function of the deformation of said underwater pipe; according to the invention, the device further comprises a set of breakable elements integral with one of said deformable underwater pipe and said receiving support, said set of breakable elements extending in a mean direction substantially parallel to said determined course; and, said breakable elements are intended to be severed successively by the other of said deformable underwater pipe and said receiving support, when said pipe is driven in movement along said determined course, so as to measure said amplitude of said movement as a function of the number severable sectionable elements.

Thus, a feature of the invention lies in the implementation of a set of breakable elements, locatable and observable, which when the deformable underwater pipe deforms both longitudinally and laterally, are cut successively; the number of scored breakable elements being a function of the maximum amplitude of deformation of the pipe. Indeed, the set of breakable elements extending in a direction parallel to the stroke of the movement of the pipe, the greater the deformation amplitude is important, the greater the number of scored breakable elements is large. The device according to the invention therefore makes it possible to measure, by means of a visualization camera on board a robot for example, the maximum amplitude, or maximum excursion, experienced during the life of the oilfield. This data is then compared with the values calculated during the design of the bottom underwater pipe and its connection ends, in order to evaluate whether they are compatible with the hypotheses of friction emitted. In addition, such a measuring device is relatively inexpensive because extremely simple, and in addition it is reliable and robust. On the other hand, the measuring device according to the invention can not only be installed between a rising pipe and a bottom pipe, but also between two bottom pipes.

According to a particularly advantageous embodiment of the invention, said set of breakable elements comprises rods, said rods having an end engaged in said deformable underwater pipe or in said receiving support and a projecting free end. of said deformable underwater pipe or said receiving support. In this way, when the underwater pipe deforms and is driven in motion, respectively, said receiving support or said deformable underwater pipe comes to bear against the free end of the rods and cuts through shear as the relative displacement of the pipe underwater and said receiving support. Advantageously, said rods have a groove or notch forming rupture primer, which allows a free section of the rods when they are deformed by the relative movement of said receiving medium and the underwater pipe. For a better visualization, the free end of the stems is colored with a color distinct from that of the seabed, so that the images generated by the observation camera, raises no doubt, on the sectioning or not of 'a rod. Indeed, when the stem is intact, its colored free end clearly appears in its initial position on the images of the observation camera. On the other hand, when the stem has been severed, its free colored end has generally been carried away by the submarine bottom currents, so that the remainder of the severed stem in engagement simply causes a point of a different color to appear. and in contrast with the other colored ends that remain intact.

In addition, said rods are kept oriented in a direction substantially perpendicular to said determined race, such that said deformable underwater pipe or said receiving support according to the embodiment, which bears on the free ends of rods, cuts them off with maximum efficiency. In addition, said rods are mounted screwed into said one of said deformable underwater pipe and said receiving support, so as to make their assembly easier. Preferably, said rods are made of plastic, for example polyamide. In this way, this material being relatively rigid and brittle, minimal deformation of the rods then causes their section, and more precisely at the notch.

According to a particularly advantageous embodiment, said set of breakable elements has at least one alignment of said rods, preferably regularly spaced, in a direction between the direction of said stroke and a direction perpendicular to said stroke, so as to ability to establish a relationship of proportionality, between the number of sectioned rods and the range of motion of the deformable underwater pipe.

According to a first embodiment of the invention, particularly advantageous, said breakable elements are integral with said receiving support, while said deformable underwater pipe is adapted to cut said breakable elements. In this way, the set of breakable elements is maintained in a fixed position relative to the seabed, and it is the movements of the deformable pipe which sever the breakable elements. To do this, and according to an advantageous characteristic, the measuring device according to the invention further comprises a carriage slidably mounted on said receiving support, said pipe being mounted integral with said carriage, and said carriage is adapted to sever said breakable elements when said underwater pipe is driven in motion and thereby drives the carriage.

According to a second variant embodiment, said breakable elements are integral with said deformable underwater pipe, while said receiving support is adapted to cut said breakable elements. In this way, it is the underwater pipe which, by deforming, causes the breakable elements, which are then cut against said receiving support which is held in a fixed position on the seabed.

Advantageously, according to this second embodiment, the measuring device further comprises a sleeve which encloses said deformable underwater pipe and which supports said breakable elements. The sleeve is then fully integral with the underwater pipe and is slidably mounted within a crown anchored to the seabed. And said ring is then adapted to sever said breakable elements when said underwater pipe is driven in motion and thereby causes the sleeve through the ring.

According to another object, the present invention provides a method for measuring the movement of a deformable underwater pipe with respect to a seabed, said deformable underwater pipe being extended on said seabed to transport fluids between two water systems. bottom, said deformable underwater pipe being capable of deforming as a function of the temperature of the fluids transported, said method being of the type according to which there is provided a reception support anchored in said seabed between said installations for receiving said deformable underwater pipe, said deformable underwater pipe being capable of being driven in movement along a determined course with respect to said support when it deforms, said movement having an amplitude which varies according to the deformation of said underwater pipe; according to the invention, the measuring method further comprises the following steps: according to which a set of breakable elements integral with one of said deformable underwater pipe and said receiving support, said set of breakable elements is provided; extending in a mean direction substantially parallel to said determined race, said breakable elements being intended to be severed successively by the other of said deformable underwater pipe and said receiving support, when said pipe is driven in motion according to said race determined and said amplitude of said movement is measured as a function of the number of severable breakable elements. This measurement is carried out and visually, for example by means of an observation camera which generates images which can then be observed on the surface. The measurement consists in counting the number of severable breakable elements in relation to the number of breakable elements initially installed.

• la Figure 1A est une vue schématique en section longitudinale et verticale du dispositif conforme à l'invention, selon une première variante de réalisation ;
• la Figure 1B est une vue schématique de dessus du dispositif illustré sur la Figure 1
• la Figure 2 est une vue schématique de dessus d'un premier élément de détail du dispositif illustré sur la Figure 1 ;
• la Figure 3 est une vue schématique d'un second élément de détail du premier élément de détail représenté sur la Figure 2, et selon une perpendiculaire ; et,
• la Figure 4 est une vue schématique en perspective du dispositif conforme à l'invention, selon une seconde variante de réalisation.

Other features and advantages of the invention will emerge on reading the following description of a particular embodiment of the invention, given by way of indication but not limitation, with reference to the accompanying drawings in which:

• the Figure 1A is a schematic view in longitudinal and vertical section of the device according to the invention, according to a first embodiment;
• the Figure 1B is a schematic top view of the device illustrated on the Figure 1
• the Figure 2 is a schematic top view of a first detail element of the device shown in FIG. Figure 1 ;
• the Figure 3 is a schematic view of a second detail element of the first detail element shown on the Figure 2 , and according to a perpendicular; and,
• the Figure 4 is a schematic perspective view of the device according to the invention, according to a second embodiment.

The Figures 1A and 1B shows a seabed 10 on which rests a bottom pipe 12 extended longitudinally in a given direction, a measuring device 14 according to the invention and a riser 16 intended to join a surface installation. The measuring device 14 comprises a receiving support 18 anchored in the seabed 10. On this receiving support 18 is installed a carriage 20 which is movable in longitudinal translation in a direction D substantially parallel to said given direction of the bottom pipe 12. The carriage 20 is movable in translation relative to the receiving support 18, which is provided with guide means not shown to specifically guide the carriage 20 in translation.

The bottom pipe 12 has a connecting end 22 held in a fixed position on the mobile carriage 20, by means of a clamping collar 24. Thus, the deformations of the bottom pipe 12, essentially related to the thermal variations that it undergoes, cause elongations or retractions of this bottom line 12 which, themselves, then cause longitudinal movement, the connecting end 22 in the direction D, and therefore the carriage 20 which it is secured. The carriage 20 is thus driven in reciprocating motion along a determined stroke, as thermal variations of the bottom pipe 12 occur. Of course, this reciprocating movement of the carriage 20 has relatively long periods that can reach several months or even several years. The measuring device 14 according to the invention then makes it possible to measure the amplitude of these reciprocating movements by means of an assembly 26 of breakable elements comprising rods 28 of plastics material. It will be observed that the set 26 of breakable elements extends in a mean direction substantially parallel to the direction of the reciprocating movements.

These rods 28 are made of plastic material, polyamide for example, and are screwed on a face 29 of a support plate 30, which is installed substantially horizontally on the receiving support 18 and is fixed thereto. The advantage of the polyamide lies in its rigidity and consequently in its ability to fracture according to a free section. The carriage 20 covers the support plate 30 and has a window 32 through which the rods 28 project. Moreover, the two transverse opposite edges 34, 36 of the window 32 form two opposed cutter bars and substantially perpendicular to the D direction of displacement of the carriage 20. These two opposite transverse edges 34, 36 are then capable of being driven in translation flush with the face of the support plate 30. Thus, it is understood that the elongation of the pipe of bottom 12, due to an increase in the temperature of the fluid or hydrocarbon therethrough, will then push the carriage 20 in a direction V opposite to the bottom pipe 12 and therefore, one of the two opposite transverse edges 34 The hydrocarbon temperature decreases to a normal operating temperature, the bottom pipe 12 then retracts and drives the carriage 20 in a direction posed P.

We will now refer to the Figure 3 , in order to describe in more detail the method of fixing the rods 28 on the support plate 30. Figure 3 , in partial view, the support plate 30 having its face location 29 in which is formed, substantially perpendicularly, a threaded orifice 38. This orifice has a depth e , less than one half a thickness of the plate 30, and it is extended by a channel 40 which opens on a rear face 42 of the support plate 30. In addition, the rod 28 consists of a threaded rod 43 surmounted by a screwing head 44. The rod 28 has an end 46 screwed into the orifice 38 and a free end 48 supporting the screwing head 44. It will be observed that the screwing head 44 makes it possible precisely to screw the end 46 into the orifice 38. In addition, the threaded rod 43 has a groove 50 a depth close to 2 mm, forming a notch between the end 46 engaged in the support plate 30 and the free end 48. This groove 50, which forms a breaking primer, allows easier section, with less than efforts, of the threaded rod 4 3 when one of the opposite transverse edges 34, 36 strikes the free end 48 of the rod 28. In addition, the channel 40 makes it possible to put the orifice 38 at the hydrostatic pressure when the support plate 30 equipped with its rods 28, is installed in the seabed. In this way, the section of the threaded rod 43 is even more straightforward.

We will now refer to the Figure 2 , illustrating in a view from above the support plate 30, through which a plurality of orifices 38 are formed, according to a particular geometry that will be described hereinafter. By way of example, this support plate 30 has a width l of 340 mm for a length L of 500 mm and a thickness of 50 mm. The threaded orifices 38 made in the support plate 30 have a diameter of 15 mm. Above all, they are practiced according to a series of alignments 52, 54, 56, 58, parallel to each other and inclined by 90 ° with respect to the length L of the support plate 30. According to their alignments, the orifices 38 are spaced apart others of a distance close to 35 mm, while along the length L , the orifices 38 are spaced from one series to another, a distance of 100 mm. In addition, the width I, there are always two holes 38 of two adjacent series, in correspondence, which define a row parallel to the width I. The set of orifices 38 extends in a mean direction substantially parallel to the length L.

Thus, in each of the orifices 38 of the 32 orifices in total, represented on the Figure 2 , of the support plate 30, a rod 28 of the type illustrated on the Figure 3 is screwed. In addition, the screw heads 44 are colored with a color distinct from that of the seabed.

Thus, by taking again the mode of implementation illustrated on the Figures 1A and 1B , where the carriage 20 is driven in translation on the receiving support 18 in the opposite direction V to the bottom pipe 12, the transverse edge 34 of the window 32 would come simultaneously, bear against the two rods of the first row r1 of the support plate 30 illustrated on the Figure 2 , and would also, as and when the carriage 20 moves, cut them simultaneously by shearing at the groove 50. By continuing its stroke, the transverse edge 34 of the window 32 would then bear simultaneously against the two rods a second row r2 contiguous to the first row r1 to cut them in turn.

This is so, the following rows, r3 to r16, assuming that the amplitude of movement of the carriage 20 is substantially equivalent to the length L of the support plate 30. The rows of rods 28 are evenly spaced from each other. others with a value of 20 mm. The presence of two rods per row, makes it possible to limit the risk that a rod has been severed by the relative displacement of the carriage 20 and the receiving support 18. If this risk does not exist, it is unnecessary to keep two rods 28 per row; if on the other hand this risk is important, it is appropriate to provide more than two rods 28 per row.

In reality, the support plate 30 is oversized so as to be able to keep a certain number of intact rods 28 on the support plate 30, and to visualize them by means of their colored screwing head 44, with respect to the already severed rods. Thus, when the bottom pipe 12 is put into service, for a determined period, for example 12 months, the carriage 20 has been able to oscillate on the receiving support 18 as a function of the temperature of the hydrocarbon which has circulated to the interior over time, and reach a maximum amplitude corresponding to a maximum of rows of stems 28 sectioned.

In this way, when after 12 months is inspected by means of a visualization camera, the support plate 30, the number of rows of intact stems remaining relative to the initial number of rows is then observed, and it is deduced therefrom maximum amplitude of the movement of the carriage 20, and consequently of the connecting end 22. In the example shown in FIG. Figure 2 in the case where for example seven rows, r1 to r7, rods 28 have disappeared, while the other rows are intact, it is deduced that the maximum excursion, or maximum amplitude, of the carriage 20 on the receiving support 18 , is 140 mm.

We will now refer to the Figure 4 , illustrating a second embodiment of the invention, according to which the breakable elements also formed of rods, are no longer integral with the receiving support 18 but the bottom pipe.

In order to facilitate the description of this variant embodiment, the analogous elements of the measuring device illustrated in the preceding figures, and having the same functions carry the same reference assigned a prime sign: "'".

Thus, we find on this Figure 4 , a bottom pipe portion 12 'engaged in a longitudinal sleeve 30'. This longitudinal sleeve is maintained in a fixed position on the bottom pipe 12 'by means of clamping collars 60. In addition, four alignments 52', 54 ', 56', 58 'of rods respectively diametrically opposed in pairs are screwed into the thickness of the longitudinal sleeve 30 '.

The receiving support consists of a ring 18 'equipped with a border which surrounds it solidarily. This ring 18 'is anchored to the seabed by partially burying said border. It is then mounted in a fixed position relative to the seabed. Alternatively, it can be installed on a not shown base. The ring 18 'allows the sliding of the longitudinal sleeve 30' when the latter is driven by the bottom pipe 12 '. In addition, the ring 18 'has two opposite shear edges 34', 36 ', intended to cut the rods 28' when the sleeve 30 'is driven in translation through the ring 20'.

Furthermore, according to yet another embodiment of the invention not shown, where it is desired to measure not only the longitudinal deformations of a bottom pipe but rather its lateral deformations, it is expected to install the movable carriage in translation on a reception support, in a direction transverse to the bottom line. In this way, the lateral movements of the pipe, cause displacement of the movable carriage, which itself induces the severing of the breakable elements.

Of course, the embodiments described above are in no way limiting, and any other embodiment can be envisaged. In particular, it is intended to install such a measuring device between two bottom pipes connected together.

Claims (12)

1. A device (14) for measuring the movement of a subsea deformable pipeline (12, 12') in relation to a seabed (10), said measuring device (14) comprising an accommodating support (18, 18') to be anchored in said seabed (10) to accept said subsea deformable pipeline, said subsea deformable pipeline (12) being liable to be made to move over a determined travel with respect to said accommodating support when it deforms, said movement having an amplitude that varies according to the deformation of said subsea pipeline;
   characterized in that it further comprises a collection (26) of frangible elements (28, 28') secured to one of either of said subsea deformable pipeline (12') and said accommodating support (18), said collection (26) of frangible elements (28, 28') extending in a mean direction that is substantially parallel with said determined travel;
   and in that said frangible elements (28, 28') are intended to be broken in succession by the other of either of said subsea deformable pipeline (12) and said accommodating support (18') when said pipeline (12, 12') is caused to move over said determined travel, such as to measure said amplitude of said movement as a function of the number of broken frangible elements (28).
2. The measuring device as claimed in claim 1, characterized in that said collection (26) of frangible elements (28) includes rods, said rods having an end (46) engaged in said one of said subsea deformable pipeline (12) and said accommodating support (18) and a free end (48) projecting from said one of said subsea deformable pipeline and said accommodating support.
3. The measuring device as claimed in claim 2, characterized in that said rods have a notch (50) forming an incipient fracture.
4. The measuring device as claimed in claim 2 or 3, characterized in that said rods (28) are kept orientated in a direction that is substantially perpendicular to said determined travel.
5. The measuring device as claimed in any one of Claims 2-4, characterized in that said rods (28) are mounted and screwed into said one of either of said subsea deformable pipeline (12) and said accommodating support (18).
6. The measuring device as claimed in any one of Claims 2-5, characterized in that said rods (28) are made of plastic.
7. The measuring device as claimed in any one of Claims 2-6, characterized in that said collection (26) of frangible elements has at least one line of said rods (28) in a direction that is between the direction of said travel and a direction that is perpendicular to said travel.
8. The measuring device as claimed in any one of Claims 1-7, characterized in that said frangible elements (28) are secured to said accommodating support (18), while said subsea deformable pipeline (12) is suitable for breaking said frangible elements.
9. The measuring device as claimed in Claim 8, characterized in that it further comprises a carriage (20) slidingly mounted on said accommodating support (18), said pipeline being mounted securely to said carriage (20), and in that said carriage is suitable for breaking said frangible elements (28) when said subsea pipeline (12) is made to move.
10. The measuring device as claimed in any one of Claims 1-7, characterized in that said frangible elements (28) are secured to said subsea deformable pipeline (12), while said accommodating support (18) is suitable for breaking said frangible elements.
11. The measuring device as claimed in Claim 10, characterized in that it further comprises a sleeve (30') that fits tightly around said subsea deformable pipeline (12') and that supports said frangible elements (28'), said sleeve being slidingly mounted inside a ring (18'), and in that said ring is suitable for breaking said frangible elements (28') when said subsea pipeline (12') is made to move.
12. A method for measuring the movement of a subsea deformable pipeline (12, 12') in relation to a sea bed, said subsea deformable pipeline being extended over said seabed in order to transport liquids between two on-bottom installations, said subsea deformable pipeline being liable to deform according to the temperature of the liquids transported, said method being of the type according to which an accommodating support (18, 18') is provided that is anchored in said sea bed to accept said subsea deformable pipeline (12, 12'), said subsea deformable pipeline being liable to be made to move over a determined travel with respect to said accommodating support when it deforms, said movement having an amplitude that varies according to the deformation of said subsea pipeline;
    characterized in that it further comprises the following steps:

    - there is provided a collection of frangible elements (28, 28') secured to one of either of said subsea deformable pipeline (12, 12') and said accommodating support (18, 18'), said collection of frangible elements extending in a mean direction that is substantially parallel with said determined travel, said frangible elements being intended to be broken in succession by the other of either of said subsea deformable pipeline and said accommodating support, when said pipeline is caused to move over said determined travel; and,

    - said amplitude of said movement is measured as a function of the number of broken frangible elements (28, 28').

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