EP0621841A1

EP0621841A1 - Fluid transfer system.

Info

Publication number: EP0621841A1
Application number: EP93903335A
Authority: EP
Inventors: Arne Smedal; Kaere Syvertsen; Edward Tan
Original assignee: MARINE CONSULTING GROUP AS
Current assignee: Advanced Production and Loading AS
Priority date: 1992-01-20
Filing date: 1993-01-07
Publication date: 1994-11-02
Anticipated expiration: 2013-01-07
Also published as: FI943416A; NO920250D0; ES2087716T3; DK0621841T3; GR3020367T3; DE69302675T2; WO1993013976A1; NO174380B; ATE138024T1; AU3463593A; DE69302675D1; NO174380C; NO920250L; EP0621841B1; FI943416A0; AU663161B2

Abstract

A fluid transfer system comprising a fluid conducting flexible pipe (4) having a first (9) and a second connector end, which pipe during use extends over an area of water, preferably totally or partially submerged in the water, between a first (8) and a second (7) hook-up point and, when not in use, is stored (5) near the first hook-up point (8), a ramp (11) curved downward in the vertical plane for supporting the flexible pipe (4) during the transfer thereof from storage position to position for use, and vice versa, and a means (13) for feeding out/hauling in the flexible pipe (4) via said curved ramp (11), the lower end of which is situated at a distance from the adjacent first hook-up point (8). The ramp (11) is movably mounted (12) for movement from a position for feeding out/hauling in the pipe to a position closer and so oriented relative to the adjacent connection point (8) that said first connector end (9) may be brought into at least approximately aligned coupling position vis-à-vis the adjacent first hook-up point (8).

Description

FLUID TRANSFER SYSTEM

The invention relates to a fluid transfer system comprisin fluid conducting flexible pipe having a first and seco connector end, which pipe during use extends over an area water, preferably totally or partially submerged in t water, between a first and second hook-up point and, when n in use, is stored near the first hook-up point, a ramp curv downward in the vertical plane for supporting the flexib pipe during the transfer thereof from storage position position for use, and vice versa, and a means, e.g., lifting cable, for feeding out/hauling in the flexible pi via said curved ramp, the lower detached end of which situated at a distance from the adjacent first hook- point.

The invention was developed primarily in connection with t need for a fluid transfer system between a maritime floati oil storage facility, for example a large barge with o storing capacity, and a so-called shuttle tanker. The o tank barge is anchored or dynamically positioned at the o production field and serves as an intermediate storage mea for the oil produced. From this barge the oil is load over into tankers, which on arrival at the field a connected to the barge by suitable mooring means, whereaft a fluid conducting pipe connection is established between t barge and tanker. The fluid conducting pipe connection formed by a fluid conducting pipe which, when not in use, stored on the barge. When this flexible fluid conducti pipe is to be utilized for fluid transfer between the bar and tanker, the flexible pipe from the barge is fed down in the water via a ramp curved downward in the vertical plan which supports the flexible pipe in the initial phase connection. As soon as a sufficient length of the flexib pipe has been fed out and is suspended down in the water fr the barge, the other end of the pipe is hauled on board t tanker and there is hooked up to a manifold, or the lik The flexible pipe end at the barge is also connected to suitable hook-up point on the barge, whereafter the flui transfer may begin. During the fluid transfer the flexibl pipe is suspended between the barge and the tanker, more less submerged in water, or if desired is freely suspende above the water surface.

After fluid transfer is completed, the flexible pipe i disconnected on the tanker side and dropped down into th water, whereafter it is disconnected on the barge side an then hauled in via the aforementioned curved ramp, to b stored on the barge until it is to be used again^".

The hook-up on the barge side can lead to difficulties due t the fact that feeding out the relatively long flexible flui conducting pipe requires a ramp which must have a certai degree of minimum curve, in order thereby to avoid damagin bend stresses on the pipe. This means that the ramp mus extend some distance out from the barge, usually from one o its ends. The hook-up point on the barge, however, i preferentially situated very close to, almost in, the actua end of the barge, which means that there is a considerabl distance between the pipe's barge connector end and the hook up point on the barge — a distance rendering it mor difficult to connect the pipe connector end to the hook-u point on the barge. An object of the invention is t provide a fluid transfer system where, in particular, thi connection problem is solved in a simple and reliable manner and according to the invention it is therefore proposed tha in a fluid transfer system of the type described above, th ramp shall be ovably mounted for movement from a positio for feeding out/hauling in the pipe to a position closer an so oriented relative to the adjacent hook-up point that sai first connector end may be brought into at least approximate ly aligned coupling position vis a vis the adjacent firs hook-up point . Hence , according to the invention , the ra i s used as a means for moving the flexible pipe so that may relatively easi ly be connected to the adj acent hook- point .

The ramp may be moved horizontally or vertically or intermediate diagonal directions, all depending on t positioning and orientation of the ramp end and the hook- point relative to one another.

In a preferred embodiment, the ramp is designed so as extend outward over the hook-up point, and it is th pivotably mounted in the vertical plane. It is particular advantageous for the pivotal movement to utilize a parallel gram joint mechanism.

It is advantageous to provide a steering device at the fr end of the ramp for maneuvering the flexible pipe so that i may be raised and lowered, i.e., moved toward and away fro the supporting surface of the ramp, thus enabling achievemen of a guided and controlled movement of the first connecto end of the flexible pipe off and onto the ramp.

The invention will now be described in more detail, wit reference to the drawings, where:

Fig. 1 is a view of a section of an oil tank barge an a tanker, in the situation existing at th commencement of the connection of the pipe,

Fig. is a view of the barge and tanker couple together, e.g, a fluid transfer system has bee established,

Fig. 3 is a view of a section from the barge end, wit a ramp according to the invention in a positio where a flexible pipeline is being fed out o hauled in,

Fig. 4 is a view of a section as in Fig. 3, but wit the ramp in hook-up position, where the flexibl pipe is aligned relative to the hook-up point o the barge, and

Figs. 5-10 show in sequence the various ramp positions Fig. 5 being a view of the ramp in a typica feed-out position, while Fig. 10 is a view o the ramp in an upward swung end position, wher the associated pipe end is well aligned i relation to the hook-up point and is ready fo final connection.

In Figs. 1 and 2 are shown a section of a barge 1 and section of a tanker 2. Barge 1 serves as a temporary storag facility for oil. Tanker 2 is a tankship that fetches oi from barge 1 and brings it to a terminal on shore.

When tanker 2 reaches barge 1, there is first established mooring connection, represented here by a hawser 3 betwee the barge and tanker. Then the fluid transfer connection is established, here represented by a flexible pipe 4. When flexible pipe 4 is not in use, it will be stored in its extended state on the barge deck 5. When the fluid conduc¬ ting connection is to be established, flexible pipe 4 is fed out from barge 1, so that it hangs down in the water, as shown in Fig. 1. With the aid of a line 6 the downward suspended pipe end is drawn up to tanker 2 and connected there to a hook-up point 7, as shown in Fig. 2. The other end of flexible pipe 4 is connected to a hook-up point 8 near the end of barge 1. The connection at hook-up point 8 may take place before flexible pipe 4 is manipulated and connected to hook-up point 7, or the connection may take place after pipe 4 has been connected to the tanker hook- point 7.

In the context of the invention, the hook-up points 8 and ₅ represent, respectively, a first and second hook-up point.

After loading is completed, pipe 4 is disconnected at 7 a lowered into the sea again with the aid of line 6, whereaft pipe 4 is drawn up and placed on deck 5 of barge 1 to ₁₀ stored there until the next fluid transfer is to take place.

The first hook-up point 8 is located at the stern end barge 1, see Fig. 3. Even though pipe 4 is flexible, i requires a certain minimum radius with respect to bend

₁₅ Therefore, during transition from the storage position deck 5 of barge 1 to the suspended position down into t water, as shown in Fig. 1, the flexible pipe must be provide with support in the form of a uniform curve, with acceptable bend radius, and to secure this support there i o used a ramp curved downward in the vertical plane. Thus when pipe 4 is brought down to its vertically suspende position in the water, the first connector end 9 of pipe will be situated at a considerable distance from hook-u point 8, as is shown in Fig. 3. In Fig. 3 is shown a ram ₅ arrangement 10 comprising a ramp 11 capable of swing movemen in the vertical plane. Ramp 11 is mounted to swing/pivot i the vertical plane by means of a parallelogram join mechanism 12, which enables ramp 11 to be moved between th normal ramp position shown in Fig. 3 and the lifted, uppe o ramp position in Fig. 4.

Flexible pipe 4 is fed out with the aid of a flexibl member, here indicated as a wire/cable 13, and will b suspended therefrom when the pipe is brought clear of ram ₅ 11, see Fig. 4. When ramp 11 is swung from the positio shown in Fig. 3 to that shown in Fig. 4, pipe 4 and the firs connector end 9 thereof will accordingly move with it, s that the pipe connector end 9 is steered in under hook- point 8. Cable 13 leads to a winch, not shown, which in Fi 4 may be activated to draw up connector end 9 for connecti to hook-up point 8.

At the bottom of ramp 11, at the free end thereof, a steeri device 14 is provided. This serves to steer and maneuver t pipe end so that when being fed out the pipe is controllab moved in when pipe end 9 has passed the lower main roller 1 until lifting cable 13 in the end piece comes into conta with the lower main roller 16 or the ramp support surface or, conversely, so that the pipe end is steered in onto ra 11 when the pipe is to be hauled in. Ramp 11 is construct with supporting rollers 15 to form a roller path for t support of pipe 4, and similar rollers are also used, indicated, on the rest of the ramp arrangement 10 and also deck 5 for rolling support of the pipe. To further clari the advantageous mode of operation of the ramp, we refer t Figs. 5-10, showing six typical sequential steps in th feeding out of a pipe, with connection of the upper end o the pipe to the hook-up point on the barge. In Fig. 5 th pipe is shown in a final phase of the actual feeding-out o discharge process. Ramp 11 is in its normal, down-swun supporting position, as in Fig. 3.

In Fig. 6 pipe 4 is brought clear of ramp 11 and is suspende by the cable (wire fork) 13. With the aid of pivot arrange ment 12, an upward swinging of ramp 11 has begun.

In Fig. 7 ramp 11 is swung slightly further upward, and Fig 8 shows ramp 11 in a steadily increasing upward swung state It is apparent that the first connector end 9 of pipe 4 belo the ramp is moving closer and closer to hook-up point 8.

In Fig. 9 ramp 11 has been swung practically all the way up and connector end 9 of pipe 4 is now situated below hook-u point 8. In Fig. 10 ramp 11 has been swung completely up t its upper end position, and pipe 4 with connector end 9 now situated in a ready (aligned) state under hook-up poi 8. With the aid of cable 13, leading to a winch that is n shown, connector end 9 may now be drawn up toward hook- point 8 and connected thereto.

The circles 12' drawn in Figs. 6-10 are included to ill strate the swing/pivot pattern of the parallelogram joi mechanism, which enables the movement of ramp 11 shown Figs. 5-10.

When the connection is to be broken, after completion of t fluid transfer, connector end 9 is disconnected from hook- point 8, and pipe 4 is lowered down slightly with the aid o cable 13, to the position shown in Fig. 10, and the proces is then reversed.

The invention is shown and described above in connection wit a preferred embodiment, where the ramp extends in the sam vertical plane as that in which the hook-up point lies. Th inventive idea resides in the fact that the ramp is used as maneuvering element to bring the connector end of the pip into a position that is close enough and so oriented relativ to the hook-up point that connection can take place preferably with the aid of a cable used during feeding out hauling in of the pipe; therefore, it is also within th scope of the invention to conceive of an embodiment where th hook-up point is situated to the side of the ramp, with th ramp then being designed for pivotal movement horizontally in order thus to manipulate the pipe into correct hook-u position. For the pivotal movement of the ramp, differen pivot mechanisms from the one shown and described may b used. Such pivot arrangements will be well known to a perso skilled in the art.

Claims

P a t e n t C l a i m s

1.

A fluid transfer system comprising a fluid conducti flexible pipe (4) having a first (9) and a second connect end, which pipe during use extends over an area of wate preferably totally or partially submerged in the wate between a first (8) and a second (7) hook-up point and, wh not in use, is stored (5) near the first hook-up point (8), ramp (11) curved downward in the vertical plane for suppor ing the flexible pipe (4) during the transfer thereof fr storage position to position for use, and vice versa, and means (13), e.g. , a lifting cable for feeding out/hauling the flexible pipe (4) via said curved ramp (11), the low end of which is situated at a distance from the adjace first hook-up point, c h a r a c t e r i z e d i n that the ramp (11) i movably mounted (12) for movement from a position fo feeding out/hauling in the pipe to a position closer and s oriented relative to the adjacent hook-up point (8) tha said first connector end (9) can be brought into at leas approximately aligned coupling position vis a vis th adjacent first hook-up point (8).

2.

A fluid transfer system according to claim 1, c h a r a c t e r i z e d i n that the ramp (11) i pivotably mounted in the vertical plane.

3.

A fluid transfer system according to claim 1 or 2 , c h a r a c t e r i z e d i n that the ramp (11) i pivotably mounted with a parallelogram joint mechanism (12).

4.

A fluid transfer system according to one of the precedin claims , c h a r a c t e r i z e d i n that on the fre end of the ramp is provided a steering device (14) f maneuvering the flexible pipe (4) and the pipe end (9) su that, when the pipe is fed out, it is controllably mov inward until the lifting cable (13), or the like, comes in contact with the ramp's support surface (15), or it steered in onto the ramp when being hauled in.