Abstract:
An apparatus provides a swivelless connection of first and second fixed positions on respective first and second structures. The structures are relatively rotatable about a common axis, through a length of flexible conduit defined by first and second space portions thereof respectively connected to the first and second fixed positions and predetermined in accordance with the extent of relative rotation to be accommodated while continuously maintaining the connection.

Description:
BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to apparatus for transfer of fluid between a fixed structure and a rotatable structure by using at least one flexible hose or conduit having at each of its ends a connector able to coact with corresponding connectors located on the fixed structure and the moveable structure, the connectors advantageously being of the rapid connection and release type. 
     The flexible hoses or conduits according to the invention can for example be tubular hoses for hydrocarbon production, electric or hydraulic control lines for drilling installations and/or hydrocarbon production from submarine wells, or can be the kill and choke types of lines for controlling an undersea well head from the surface. 
     The moveable structure according to the invention can in particular be a drilling or production ship provided with a &#34;moon-pool&#34; type well or housing inside of which is a fixed structure at least partially cylindrical, such as a turret or table, and which is connected to anchor lines to the undersea bottom or is otherwise immobilized under the action of dynamic positioning means installed on the movable structure. The transfer hose or hoses, in accordance with the invention, are connected between the fixed cylindrical structure and the submarine wellhead or wellheads. In general, the cylindrical structure can be in the form of a turret having an upper platform or table supported by a rolling or bearing mechanism on the deck of the ship. The ship is thus able to turn or rotate with respect to the turret, under the influence of wind, waves, and current. 
     BACKGROUND OF THE INVENTION 
     Since the line or lines for fluid transfer must be connected at one end to the ship, which is the moveable structure, and at the other end to the fixed turret around which the ship turns, problems occur in insuring the total security of the fluid transfer connection, in particular during extensive rotations which may involve several turns of the ship in the same direction about the turret. 
     One possible solution is to provide, on the turret, a swivel joint through which the transferred fluids can flow. However, in view of the relatively high pressures which hydrocarbons in particular can reach during their production, for example, pressures commonly of one hundred bars or more, swivel joint mechanisms are not very reliable, and present numerous problems particularly with respect to sealing. 
     Further, the gases from petroleum production are often explosive and, when present in the swivel joint, can cause severe accidents where the hoses or conduits also have electrical lines. 
     Such problems have led to a search for solutions to eliminate the use of swivel joints. These solutions, in view of the very large dimensions of the structures involved and the complex kinematics and motions, have resulted in structures which are both very expensive and relatively difficult to operate. 
     SUMMARY OF THE INVENTION 
     The present invention provides an apparatus which, while being relatively simple and economical, insures the transfer of fluid reliably without using a swivel joint mechanism. 
     The apparatus according to the invention is characterized by the fact that the hose or conduit (or each of the hoses, pipes or conduits) extends around a curved support surface advantageously constituted by the periphery of a wheel having at least one peripheral groove, the axis or axle of the wheel preferably being placed radially with respect to the fixed structure and orthogonally to the axis of this fixed structure. The curved hose support surface is guided on the fixed structure and/or the moveable structure so as to move concentrically around the fixed structure in the region of the sidewall or periphery of the fixed structure. 
     In one embodiment of the invention, the curved support surface, takes the form of a roller track or a curved gutter. 
     In the embodiment in which the curved support surface is on a wheel, the wheel is preferably mounted for free rotation but can, as a variation, be provided with driving means for rotating the wheel. In addition, the curved support surface is associated with driving motor means acting in such a way during its circular displacement around the fixed structure that tension is exerted on the hose(s) or conduit(s) by the corresponding curved support surface. 
     In a first embodiment the curved support surface can be mounted on a moveable stand or framework, the framework in one embodiment being supported by and guided at its lower end on a rail or track on the moveable structure, and being guided at its upper end on a rail or a track supported by an upper portion of the fixed structure. 
     In a second embodiment, the curved support surface can be guided in a peripheral guide made in the sidewall of the fixed structure. 
     Storage means for the flexible hoses are provided on the moveable structure and on the fixed structure. 
     The storage means on the moveable structure can advantageously take the form of an annular well or recess in which the successive turns of the flexible hose or conduits are placed one above the other vertically. 
     This solution is the most useful, but of course as a variation, the successive turns can be arranged horizontally on a platform of the moveable structure. 
     The storage means on the fixed structure have, in a first embodiment, at least one recess opening radially outwardly of the sidewall of the fixed structure in the region of its upper portion, the windings or turns of the hoses being placed horizontally in the groove, or grooves, in the case of multiple conduits. 
     As a variation, the storage means on the fixed structure can include a vertical opening groove formed in the fixed structure in the vicinity of its periphery, and in which the successive turns or windings engage one above the other vertically. 
     Means for guiding the flexible hoses can be provided, preferably on the curved support surface(s), the guilding means also being provided on the fixed structure and/or the moveable structure, to facilitate the storing and unwinding of the hose or hoses. 
     According to the invention, there can be provided a curved support surface, or as a variation a set of curved support surfaces, in particular in the form of a single wheel with several peripheral grooves which can be used for a set of hoses when arranged in a bundle or group. 
     In the case of production conduits, and to allow a significant number of successive rotations in the same direction of the movable structure with respect to the fixed structure, two hoses can be provided, each associated with a different curved support surface, the two hoses being permanently connected at their respectively corresponding, common end, either to the fixed structure or to the moveable structure. Each of the structures is provided with connectors for joining to the corresponding connectors of the hoses or conduits, and the length of each hose is equal to or slightly greater than one half the circumference of the fixed structure. Such an arrangement provides for multiple revolutions by selectively connecting and disconnecting the hoses as the moveable structure, namely the ship, revolves slowly about the fixed structure. In this arrangement, valves are provided to stop the flow of fluid through one hose just before it is disconnected, and to permit flow through the other hose or conduit just after it is connected. 
     Other features and characteristics of the invention will become apparent from the following description which is presented as a nonlimiting example of preferred embodiments with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     FIG. 1 shows a production support in the form of a ship, provided with the fluid transfer apparatus according to the invention; 
     FIG. 2 is an enlarged schematic view, half in cross-section showing one example of the apparatus according to the invention: 
     FIG. 2a shows a variation of the hose storage arrangement of the apparatus of FIG. 2: 
     FIG. 3 is a top view schematically showing the apparatus of FIG. 2: 
     FIGS. 4a to 4d are diagramatic views showing the principle of operation of the device according to the invention, and showing the components of the apparatus in different relative rotational positions; and 
     FIGS. 5a to 5i are diagramatic schematic views showing the principle of operation of a second embodiment of the device according to the invention in different relative positions of rotation. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows a production support ship 1 (i.e., a movable or rotatable structure) having a &#34;moon-pool&#34; well or housing 2 within which is a cylindrical turret 3 having a platform or table 4 supported by the deck of the ship via a roller mechanism 5. 
     The turret 3 is held fixed or essentially fixed against rotation by connecting the turret to the undersea bottom with anchor lines 6. 
     The numeral 7 designates a set of flexible hoses or conduits for raising hydrocarbon products from submarine wells by remote control. Such flexible hoses 7 are made and marketed in very long lengths by applicant&#39;s assignee. For brevity of description, such a set or group of hoses or conduits 7 will hereafter be designated by the term flexible conduit 7. 
     Flexible conduit 7 traverses the turret 3 vertically and extends upwardly through the table 4 located at the upper end of the turret. Hose 7 has a connector 8 which can be joined to a corresponding connector 9 of a hose or conduit 10 which has at its other end an connector 11 which can be connected to a connector 12 of a conduit 13. 
     Connectors 8 and 9 and 11 and 12 are of the rapidly releasable and connectable type, which are presently used in the petroleum industry. 
     The hydrocarbons raised from the marine floor and which pass through conduit 7 must pass through hose 10 and then through conduit 13 to fill the hydrocarbon receiving tank of the ship. 
     FIGS. 2 and 3 show one embodiment of an apparatus according to the invention. 
     As shown, there is a wheel 14 having a peripheral groove 15, the wheel being mounted for rotation about a horizontal axle in the region of the side wall 4a of the upper table 4 of turret 3. 
     The wheel 14 is mounted on a frame or crossbar 16 having roller means 25 at its lower end for rolling on a circular track 17 supported by the deck 18 of ship 1. At the upper portion of crossbar 16 there are provided means rolling on a rail or track 19 supported by table 4 of the fixed structure 3. 
     To store hose 10 on the turret or fixed structure 3, a radially outwardly opening peripheral groove 20 is provided in sidewall 4a to provide for horizontal storage of hose 10. 
     In a variation, as shown in FIG. 2a, an annular groove 21 is provided in the top of table 4. 
     An annular well 21&#39; is also provided for vertical storage of the flexible hose 10 on the deck of the ship i.e. the rotatable structure. 
     Motor means 22 are provided to rotate framework 16 and correspondingly, wheel 14 and its horizontal axle around table 4. Suitable conduit guide means (not shown) are also provided on the crossbar 16 to guide the conduit 7 in the storage means such as the grooves 20, 21, and 21&#39;. 
     FIGS. 4a to 4d these FIGS. show schematically the different positions of the apparatus according to the invention, in different relative positions of the ship 1 (which constitutes the rotatable structure) with respect to the fixed structure, namely, the turret 3 and its table 4. The relative positions shown as well as the directions of the arrows S1, and A, are the directions seen by an observer on the deck 18 of the ship. 
     In the position shown at FIG. 4a, the flexible hose 10 is substantially entirely stored on the deck 18 of the ship 1. 
     FIG. 4b shows an intermediate relative rotational position of the ship 1 with respect to the table 4, in which hose 10 is in the process of moving from the ship 1 (i.e., the) rotatable structure, to then be stored on the table 4 (i.e., the fixed structure), during relative rotation of the rotatable structure with respect to the fixed structure, in the direction seen by an observer on the deck of the ship 1, and which is indicated by arrow S1. 
     As can be seen, the wheel 14 moves in the direction indicated by arrow A, relative to fixed structure 4, and the motor means 22 associated with the crossbar 16 exerts on the wheel 14 and crossbar 16, a force directed in the direction of arrow F to maintain pressure against and to tension hose 10 which is positioned in the peripheral 15 groove of wheel 14. 
     FIG. 4c shows the final position of the hose 10 which is now seen to be substantially entirely stored or supported on fixed structure 4. It is believed evident that as the rotatable structure 1 revolves relative to the fixed structure 4, the hose 10 is transferred from a storage position on the movable structure 1 to a storage position on the fixed structure 4 as shown at FIG. 4c. 
     FIG. 4d shows an intermediate position of the hose 10 and its storage, during rotation of the rotatable structure 1 in the direction indicated by the arrow S2, from the starting position of FIG. 4c. As shown at FIG. 4d, the hose 10 is being released or removed from the fixed structure 4 and stored on the rotatable structure. The wheel 14 then moves in the direction of arrow B around the fixed structure 4. 
     It will be understood that the length of hose 10 is selected as a function of the number of turns in one direction which it is desired to permit for the rotatable structure 1 relative to the fixed structure 4, without having to connect and disconnect the connecting means 8, 9 or the connecting means 11, 12. 
     Referring now to FIGS. 5a to 5i, an embodiment will now be described which allows, while using only short lengths of flexible hoses, any number of rotations in the same direction of the rotatable structure with respect to the fixed structure, while insuring continuity of the transfer of fluid between the fixed structure and the movable structure. 
     In this embodiment, there two hoses 10a and 10b each provided with end connectors 9a, 11a, and 9b, 11b respectively, connectors 9a and 9b remaining permanently connected to the corresponding connector not shown, on the fixed structure 4. 
     In this embodiment, two wheels, 14a and 14b are provided, one for each of the tubular hoses 10a and 10b. 
     At the beginning of rotation of the rotatable structure 1 with respect to the fixed structure 4 (FIG. 5a), it is hose 10a which has its connector 11a connected to the connector 12 on the ship or rotatable structure 1. During the rotation phases shown at FIGS. 5b to 5e, wheels 14a and 14b turn to respectively wind and unwind the lengths of the hoses 10a and 10b respectively until the positions shown in the FIG. 5e are reached in which wheel 14b supporting hose 10b moves to the region of connector 12 on the rotatable structure 1. At this time, by means not shown, the connector 11b is connected to connector 12 which is provided with two connectors. During the beginning of the following rotation phase, the transfer of fluid which was previously carried out by hose 10a is transferred to hose 10b. Connector 11a of hose 10a is then disconnected. It is to be understood that suitable valves are provided in the hoses 10a and 10b, preferably adjacent the connector ends 11a and 11b, to enable shutting off the flow of the fluid selectively from either of these hoses. 
     During later phases of rotation, wheels 14a and 14b continue to turn, eventually reaching the position of FIG. 5i in which connector 11a of hose 10a is connected to connector 12, followed by disconnection of connector 11b of hose 10b, thereby maintaining continuity of transfer of fluid as described above. Thus, the structures have returned to the relative positions of FIG. 5a. 
     As a variation, the hoses 10a and 10b can remain permanently connected to the movable structure 1, and the connecting and disconnecting operations can be carried out at the points of connection of these holes 10a and 10b to the fixed structure 4. Continuity of the transfer of the fluid is again maintained. 
     Although the invention has been described in connection with a particular application and particular embodiments, it is not thereby limited, and numerous changes and variations can be made without departing from the scope or spirit of this invention.