WO1999053341A1

WO1999053341A1 - Automated streamer production

Info

Publication number: WO1999053341A1
Application number: PCT/IB1999/000624
Authority: WO
Inventors: Oddvar Amundsen; Odd Arve Sagstad; Reidar Stusdal; Rolf Anthonisen; Dag Samsonsen
Original assignee: Schlumberger Holdings Limited; Schlumberger Canada Limited; Services Petroliers Schlumberger
Priority date: 1998-04-15
Filing date: 1999-04-09
Publication date: 1999-10-21
Also published as: NO20005172L; GB9807997D0; NO20005172D0; AU2951999A

Abstract

An automated streamer production line for producing 100 metre long streamer sections comprises an elongate bench provided with tensioning devices for supporting the Kevlar rope harness of the streamer under tension. At one end of the bench, an automatic feed device automatically feeds groups of components, typically spacers, foam sections and hydrophones, onto the Kevlar ropes, via an in-feed 'lock' or 'sluice' defined by two spaced apart clamping devices. The clamping devices are opened sequentially, so as to maintain the Kevlar ropes continuously under tension as the components are fed onto them. A shuttle then moves the components along the Kevlar ropes to the desired position, and at least some of the components, typically the spacers, are automatically glued to the ropes.

Description

AUTOMATED STREAMER PRODUCTION

The present invention relates to an automated production line apparatus for the manufacture of streamers of the kind used in marine seismic surveys.

Such streamers generally consist of a plurality of rope harness subassemblies, each of which consists of a pair of elongate members, for example, Kevlar ropes, on which are threaded a number of components, including hydrophones, foam sections and spacers. Each rope harness subassembly is, typically, provided with connectors which permit it to be coupled to other similar subassemblies to form the required streamer length.

In accordance with the invention, there is provided a production line apparatus for the assembly of rope harness subassemblies for incorporation into seismic streamers, the apparatus comprising:

support means for supporting at least one elongate member;

guide means which, in use, extend longitudinally of, and adjacent to, the elongate member;

control means; and

at least one carriage mounted for movement to and fro along the guide means, and hence, longitudinally of an elongate member supported by the support means; the carriage having means for engaging at least one component supplied to an inlet end of the elongate member to move said at least one component along the elongate member to a predetermined position on the elongate member under the control of the control means.

Using a suitable production line control means, the apparatus can move the desired components to their required locations

- 1 - along the elongate Kevlar ropes, which may be up to 99 m in length, automatically.

Preferably, the apparatus includes inlet means operable by the control means to permit the assembly at the inlet end of the elongate member of a component group comprising at least two components, the components of the said component group, in use, being moved together along the elongate member by a single pass of the or each carriage. Thus the carriage may move several neighbouring components along the Kevlar rope in a single movement, saving time and reducing wear.

In a preferred embodiment, the apparatus is provided with an auxiliary carriage operable by the control means to move the or each component from the inlet end of the elongate member to a location proximate to said predetermined position and a second main carriage operable to move the or each component to its final location along the length of the elongate member. Since the auxiliary and main carriages can operate simultaneously, operation of such production line apparatus can be made faster than in a system using a single carriage to achieve final positioning of the components.

The invention further provides a method for assembling rope harness subassemblies for incorporation into seismic streamers, the method comprising:

supporting at least one elongate member; and

controlling movement of at least one carriage to and fro along guide means which, in use, extend longitudinally of, and adjacent to, an elongate member supported by the support means; the carriage engaging at least one component supplied to an inlet end of the elongate member to move said at least one component along the elongate member to a predetermined position on the elongate member.

An embodiment of production line apparatus in accordance with the invention will now be described in detail, by way of example, with reference to the drawings, in which: Figure 1 is a schematic diagram of a rope harness sub-assembly which forms part of a typical seismic streamer;

Figures 2(a) to (c) are schematic diagrams of the inlet end of an automated production line in accordance with the invention;

Figure 3 is a sectional view of a crimp sleeve securing the Kevlar ropes of the rope harness subassembly to guide bars of the production line inlet end of Figures 2(a) to (c) ;

Figure 4 is a detailed lateral view of a locking clamp of the production line of Figures 2(a) to (c);

Figure 5 is a schematic view of an automated assembly line in accordance with the invention, seen from above;

Figure 6 is a cross section of a guide frame forming part of the production line of the invention;

Figure 7 is a detailed view of a main shuttle of the production line of Figures 2(a) to (c);

Figures 8(a) and (b) are a front view and side respectively, of parts of the main shuttle of Figure 7; and

Figure 9 is a detailed view of a tensioning cylinder of the production line of Figures 2(a) to (c) .

The rope harness subassembly 10 shown in Figure 1 comprises two parallel ropes 12 on which are threaded the hydrophones 14 which form the main functional part of the streamer. The subassembly 10 may be, for example, approximately 99 m long and several such subassemblies may be connected in line to form the streamer.

The ropes 12 may, for example, be seven strand constructions made of Kevlar (registered trade mark) with a polyurethane jacket. They are coupled at their ends to connectors 16 and 18, one male and one female, by means of which the subassembly may be connected to other similar subassemblies to form a streamer. The pair of parallel Kevlar ropes 12 are connected to one another and to the connectors 16 and 18 by means of a short loop 17, at each end of the harness, of rope of a more flexible kind than the Kevlar rope used for the main part of the rope harness. For example, the loops 17 may be made of rope of the kind sold under the trade mark Dyneema (Registered trade mark) which is a twelve strand rope of an aramid-type fibre.

Typically, the hydrophones 14 are separated and spaced from one another by foam sections 19 and spacers 15 threaded on the Kevlar ropes 12. The foam sections 19 fill substantially all the space between the hydrophones 14 and the spacers 15. The components are held in place on the Kevlar ropes 12 by gluing at least some of the spacers 15 with, for example, cyanoacrylate glue, to the ropes 12. The hydrophones 14 are held in place between pairs of spacers 15 and are wedged in position by the foam sections 19 which are also 'trapped' between pairs of adjacent spacers 15.

The inlet end of an automated production line in accordance with the invention is shown schematically in Figures 2(a), (b) and (c) .

The production line is of generally linear format and the inlet end is positioned at one end of the Kevlar ropes 12 which will form the 'backbone' of the rope harness subassembly. The Kevlar ropes 12 (which are arranged side by side so that only one is visible in Figures 2(a) to (c) ) are held under tension, typically equivalent to 200 kg, and have their free ends secured to guide bars 22, which form part of the production line, by means of crimp sleeves 30 shown in greater detail in Figure 3.

As can be seen from Figure 3, the crimp sleeves 30 have at one end a blind bore 32 into which the end of the Kevlar rope 12 is inserted and their other end a screw-threaded member 34 which screws into a suitable threaded socket formed in the end of the guide bar 22. The cylindrical wall of the blind bore 32 of the crimp sleeve 30 is crimped onto the Kevlar rope 12 so that the crimped-down diameter of the sleeve is the same as that of the

4 - uncrimped part of the Kevlar rope. This facilitates movement of the other elements of the subassembly onto the Kevlar ropes 12.

The guide bars 22 extend from the ends of the Kevlar ropes 12 to free ends adjacent inlet matrices from which the other elements of the subassembly 10 are supplied. Between the ends of the guide bars 22, a central "in-feed lock' is defined by two locking clamps 24 (shown in greater detail in Figure 4) which, when their jaws 25 are closed, fit closely adjacent the guide bars 22 and, when the jaws 25 are open, are spaced from one another so as to allow the passage of the elements which are to be threaded onto the Kevlar ropes 12 therethrough. As can be seen from Figure 4 the jaws 25 are opened and closed by means of hydraulic cylinders 27 coupled to the jaws 25 by means of suitable linkages 29.

The inlet end of the production line also comprises containers 41 for foam sections 19, spacers 15 and hydrophones 14, mounted above the level of the main production line so as to take advantage of gravitational forces in feeding components to the inlet of the production line proper. The containers 41 include built-in aligning and feeder mechanisms which are controlled from a central control station. Typically, foam sections 19 and spacers 15 are led to the production line through tubes, while the hydrophones 14 slide down steel guides.

Foam sections 19, spacers 15 and hydrophones 14 are supplied to a pair of inlet matrices 44, each of which is associated with one of the two rope harnesses on which the production line will work simultaneously. The inlet matrices 44 control the number and order in which components are mounted on the rope harnesses 12. The tubes from the foam and spacer containers are connected to the inlet matrices 44. Each matrix 44 is moveable sideways and up and down under the control of pneumatic cylinders (not shown) .

The inlet end of the production line shown in Figures 2(a) to (c) lies at one end of the production line. During manufacture of the rope harness subassembly 10, the Kevlar rope harnesses 12 are extended to their full length to tension cylinders 40 as shown in Figure 5 and in greater detail in Figure 9. The Kevlar rope harnesses 12 are supported between the inlet end and the tensioning cylinders 40 on guide frames 50 which serve to support both the harnesses 12 and guide rails 52 on which are mounted two shuttles 42 and 43 whose operation will be described in detail below.

The guide frames 50 are shown in detail in Figure 6. Each guide frame 50 comprises a support post 54 bolted to the floor at its lower end 51 and having at its uppermost end a support member 53 carrying a pair of precision machined steel guide rails 52. Two separate shuttles 42 and 43 run along the guide rails 52 on steel wheels and are driven, for example, by means of electrical servo motors connected through gears to a toothed bar 55 mounted on the support member 53 of the guide frame 50. Electrical cables connected to the shuttles are routed through a cable channel 56 mounted on the support member 53 between the guide rails 52.

In addition to the guide rails 52 and their support member 53, each support post 54 also carries, below the support member 53, a support table 57 extending generally horizontally and transversely of both the guide rails 52 and the harnesses 12. The support table 57 has adjacent its free edges, remote from the support post 54, a generally flat, smooth support surface over which the Kevlar ropes 12 of two harnesses on which the production line is working pass on their way to the tensioning cylinders 40, one on each support arm 56. The support table 57 is provided, adjacent to and on each side of the support post 54, with a shallow, trough-like depression 58 capable of containing up to three Kevlar rope harnesses ready for completion. Thus, the production line can be loaded with a total of eight rope harnesses for completion before the production line goes into operation, allowing for fewer stoppages and more efficient operation.

The production line carries out the following operations automatically under the control of a central control unit 59:

- 6 — feeds spacers 15, foam sections 19 and hydrophones 14 from containers 41 into the correct order and alignment;

— moves the components onto the Kevlar ropes;

— moves the components along the ropes to specified locations along their length;

— glues the spacers 15 to the ropes at the required positions .

Operation of the production line is as follows.

Before automatic assembly can be commenced, the Kevlar ropes 12 are connected to one another and to the male connector 16 by means of a Dyneema rope loop. The ends of the Dyneema rope loop 17 are secured to the ends of the Kevlar ropes 12 by means of crimp sleeves 60 shown in Figure 1. The male connector 16 is then coupled to the tensioning cylinders 40. The other ends of the ropes 12 are connected to temporary crimp sleeves 30 and the threaded members 34 on the temporary crimp sleeves 30 are screwed into the ends of the guide bars 22 After the ropes 12 have been checked to ensure that they are lying straight and unfouled over the smooth surfaces on the support table 57, the rope harnesses are placed under tension by means of the tensioning cylinders 40.

Foam sections 19, spacers 15 and hydrophones 14 are then supplied to the inlet matrices 44 and are fed onto the guide bars 22, in the required order, by means of pressurized air from nozzles under the control of the central control unit. The order in which foam sections 19, spacers 15 and hydrophones 14 are fed onto the guide bars 22 is determined by appropriate movement of the inlet matrices 44 so that the required components are aligned with the guide bars 22 in turn.

Under the control of suitable pneumatically controlled pusher tools, the components are moved into the central 'in-feed lock' on the guide bar 22 between the locking clamps 24. During this phase of the operation, as can be seen from Figures 2(a) and

- 7 - (b) , the locking clamp remote from the inlet matrix 44 is closed so as to maintain tension on the ropes, while the clamp 24 adjacent the inlet matrix 44 is open, so as to allow the components to enter the in-feed lock.

Once the required group of components, foam sections 19, spacers 15 and hydrophones 14, has been assembled on the guide bar 22 in the in-feed lock, the locking clamp 24 adjacent the inlet matrix 44 closes and that at the remote end of the in-feed lock opens to allow the components to pass through it, along the guide bar 22 and onto the Kevlar ropes of the rope harness 12, as shown in Figure 2(c) . The group of components assembled in the in-feed lock is moved onto the ropes 12 by means of one of the two shuttles 42, referred to hereinafter as the auxiliary shuttle, while the locking clamp 24 adjacent the inlet matrix 44 maintains the tension in the ropes.

As outlined above, the auxiliary shuttle 42 runs on the guide rails 52 along a path parallel to the rope harnesses 12 supported by the plurality of support frames 50. The auxiliary shuttle 42 is provided with pneumatically operated gripping jaws capable of gripping the spacers 15 for movement with the shuttle 42. Only the spacers 15, which are relatively robust, are held by the shuttle gripping jaws; each group of components assembled in the in-feed lock is arranged to have a spacer 15 as the 'rearmost' component of the group so that the foam sections 19 and hydrophones 14 in the component group are simply pushed along the ropes 12 of the harness ahead of the rearmost spacer 15 which is gripped by the auxiliary shuttle.

The auxiliary shuttle 42, acting under the control of a central processor unit, transports the group of components assembled in the in-feed lock to a predetermined position along the ropes of the harness 12. At the predetermined location on the harness the second or 'main' shuttle 43 collects the group of components for final positioning.

The main shuttle 43, shown in detail in Figures 7 and 8(a) and (b) is, like the auxiliary shuttle 42, provided with gripping jaws 70 for gripping the spacers 15 but it also has servo motors 72, for controlling the position of the gripping jaws 70 and the spacers 15 they carry, and glue dosing nozzles 74, by means of which the spacers 15 may be glued to the Kevlar ropes of the harnesses with, for example cyanoacrylate glue. The shuttle 43 runs on wheels 76 which, as described above run on guide rails 52 supported by guide frames 50. The gripping jaws 70 are, as can be seen from Figures 8(a) and (b) , operated hydraulically and are provided with circumferentially extending slots 78 through which the glue dosing nozzles 74 may apply glue to the Kevlar ropes 12 once the spacers are in position.

Once the spacers 15 have been glued in position, the remaining operations required to finish the harness 10, for example, electrical connections to the hydrophones 14, can be completed manually.

Once assembly of the components on the Kevlar ropes 12 has been completed, the temporary crimp sleeves 30 are cut away and the second loop of Dyneema rope 17 together with its associated female connector 18 are secured to the end of the Kevlar ropes by means of crimp sleeves 60. The rope harness sub-assembly is then completed by the addition of an outer tubular sheath over the whole assembly. The outer sheath is filled with kerosene which is absorbed by the foam sections 19 and controls the buoyancy of the finished streamer.

Both of the auxiliary and main shuttles 42 and 43, as well as the various pneumatic actuators controlling the locking clamps 24, the gripping jaws on the shuttles and the supply of components to and from the inlet matrices 44, operate under the control of a central production line control unit, for example, an Omron (registered trade mark) production line control unit. The production line control unit controls all pneumatic systems and servo motors and to facilitate this receives input signals from limit switches, push buttons and other sensors mounted on the system so that it is able to determine the location of the movable parts of the system and the condition of any multi- condition components of the production line. The automated production line described allows positioning of the components and gluing of the spacers to fix the components, once positioned, automatically. In the embodiment described, two harnesses are completed simultaneously and the supply and alignment of components is entirely automated. Different component sequences can be chosen simply by suitable manipulation of the program controlling the inlet matrices 44.

Because the production line is largely automated, it can be operated from a central production line control unit, requiring minimum staffing levels.

Not all of the components need to be threaded onto both ropes 12. For example, the housings of the hydrophones 14 can be threaded onto one of the ropes 12, and provided with a groove which engages and locates against the other rope. In the limit, all of the components can engage and locate against the ropes 12 by way of grooves provided in them for that purpose, in which case the in-feed locks can be replaced by single clamps to maintain the tension in the ropes.

- 10 -

Claims

1. A production line apparatus for the assembly of rope harness subassemblies for incorporation into seismic streamers, the apparatus comprising:

support means for supporting at least one elongate member;

control means; and

2. Apparatus according to claim 1, further comprising tensioning means for tensioning the elongate member so as to facilitate movement of the at least one component along said elongate member by the or each carriage.

3. Apparatus according to claim 2, in which the tensioning means includes at least one pneumatic cylinder operable by the control means.

4. Apparatus according to any preceding claim, in which the guide means includes at least one rail for engagement by a wheel of the or each carriage.

5. Apparatus according to any preceding claim, provided with an auxiliary carriage operable by the control means to move the or each component from the inlet end of the elongate member to a location proximate to said predetermined position and a

11 - second main carriage operable to move the or each component to its final location along the length of the elongate member.

6. Apparatus according to any preceding claim, in which the or each carriage is provided with gripper means for gripping one or more components to move the said component or components along the elongate member.

7. Apparatus according to any preceding claim, in which the or the main carriage includes means for gluing at least some of the components to the elongate member once the or each component is in its final location along the elongate member.

8. Apparatus according to any preceding claim, including inlet means operable by the control means to permit the assembly at the inlet end of the elongate member of a component group comprising at least two components, the components of the said component group, in use, being moved together along the elongate member by a single pass of the or each carriage.

9. Apparatus according to any preceding claim, wherein the inlet means includes at least one guide member coupled, in use, to an end of the elongate member so as to form a continuation thereof whereby a component on the guide bar can slide from the guide bar onto the elongate member; the guide bar being provided with first and second clamp means capable of movement from an open position, in which components may pass along the guide bar past the clamp means, to a closed position in which the clamp means grips the guide bar so as to maintain tension in the elongate member and so as to prevent components moving along the guide bar past the clamp means; the first and second clamp means being operable by the control means so that, in use, the first clamp means is in the closed position, gripping the guide bar, while one or more components is moved onto the guide bar past the open second clamp means; the second clamp means being closed to maintain tension in the elongate member while the said component or components are moved from the guide bar onto the elongate member past the open first clamp means.

12

10. Apparatus according to any preceding claim, in which the components include some or all of hydrophones, spacers and foam sections .

11. A method for assembling rope harness subassemblies for incorporation into seismic streamers, the method comprising:

supporting at least one elongate member; and

controlling movement of at least one carriage to and fro along guide means which, in use, extend longitudinally of, and adjacent to, an elongate member supported by the support means; the carriage engaging at least one component supplied to an inlet end of the elongate member to move said at least one component along the elongate member to a predetermined position on the elongate member .

12. A method according to claim 11, further comprising tensioning the elongate member so as to facilitate movement of the at least one component along said elongate member by the or each carriage.

13. A method according to claim 11 or claim 12, wherein an auxiliary carriage is operable to move the or each component from the inlet end of the elongate member to a location proximate to said predetermined position and a second main carriage is operable to move the or each component to its final location along the length of the elongate member.

14. A method according to any of claims 11 to 13, in which the or each carriage grips one or more components to move the said component or components along the elongate member.

15. A method according to any of claims 11 to 14, in which the main carriage is operable to glue at least some of the components to the elongate member once the or each component is in its final location on the elongate member.

16. A method according to any of claims 11 to 15, wherein a component group comprising at least two components is assembled

- 13 - at the inlet end of the elongate member, the components of the said component group, in use, being moved together along the elongate member by a single pass of the or each carriage.

17. A method according to any of claims 11 to 16, wherein at least one guide member is coupled to an end of the elongate member so as to form a continuation thereof whereby a component on the guide bar can slide from the guide bar onto the elongate member; the guide bar being provided with first and second clamp means capable of movement from an open position, in which components may pass along the guide bar past the clamp means, to a closed position in which the clamp means grips the guide bar so as to maintain tension in the elongate member and so as to prevent components moving along the guide bar past the clamp means; the first and second clamp means being operable by the control means so that, in use, the first clamp means is closed to grip the guide bar, while one or more components is moved onto the guide bar past the open second clamp means and the second clamp means is closed to maintain tension in the elongate member while the said component or components are moved from the guide bar onto the elongate member past the open first clamp means .

- 14