CN101674975A

CN101674975A - Floating platform for operation in regions exposed to extreme weather conditions

Info

Publication number: CN101674975A
Application number: CN200880014490A
Authority: CN
Inventors: K·塞弗森
Original assignee: Sevan Marine ASA
Current assignee: Sevan Marine ASA
Priority date: 2007-03-21
Filing date: 2008-03-12
Publication date: 2010-03-17
Also published as: EP2139754A4; US20100143045A1; KR101532234B1; NO20071491L; CA2681204A1; RU2009138730A; EP2139754A1; CA2681204C; WO2008115068A1; KR20090121403A

Abstract

A floating platform for drilling after or production of hydrocarbons comprises a semi-submersible main platform (2) carrying process and/or drilling equipment at its upper surface (7), and which is designed as a vertical, essentially flatbottomed cylinder. The main platform (2) is provided with a central vertical shaft (8) which at its lower end is adapted for reception and releasable locking of an anchoring buoy (3) carrying fastening equipment for anchoring lines (10) and for risers (14, 15) and umbilicals.

Description

Be used for floating platform in the zone operation that is exposed to extreme weather conditions

Technical field

The present invention relates to a kind ofly be used for after the drilling well or the floating platform of offshore production hydro-carbon, comprise: the surface has the main platform of the semisubmersible of Fabricating machinery and/or drill outfit thereon, and the main platform design of this semisubmersible becomes vertical, basic flat bottomed cylinder.

Background technology

According to Norwegian Patent NO.319971, be known as above-mentioned design-calculated platform.Have the platform of cylinder platform body by design, pitching motion and rolling motion are significantly reduced.In addition, this platform has very big load carrying ability with respect to production or drill outfit, and has the memory capacity of very big oil, fuel etc.Platform has direction independence with respect to surrounding environment, therefore can be by means of simple fixing anchoring system anchoring.In addition, lifter can be directly connected to the receiving system on the platform, does not need rotation to move etc.

Because the operation in zone, the arctic has the threat on iceberg, this requires floating platform must have the ability to separate anchoring system and lifter.When regional operation in the appearance of extreme climate low frequency, for example suffer in the zone of hurricane, can the separating floating device be very favorable.Because this can reduce the requirement to anchoring system greatly.

To carry out shortcoming that routine separates be to lose time and interrupt transmission with producing hydro-carbon, and the anchoring rope separates separately with lifter in routine is separated.In addition, in order to take possible leakage into account and, can separated equipment to be very expensive from marine pull-up.Separate and be connected subsequently the several weeks of production that rope and/or lifter may need to end production facilities of anchoring.Connect and generally need employ storeship to be used for pull-up anchoring rope and lifter.Therefore connection work is subject to the influence of climatic conditions.

Summary of the invention

The purpose of this invention is to provide the place that a kind of platform is used in the zone that suffers extreme climate or floating ice and iceberg occur uses.

Above-mentioned purpose is achieved by the platform of the type of the introductory statement according to the present invention, it is characterized in that, main platform is provided with the vertical vertical shaft at the center, be suitable for receiving and locking releasedly anchored buoy in its lower end, this anchored buoy has the rope and be used for lifter and the securing device of umbilical cord of being used to anchor.

Description of drawings

Further specify the present invention relevant below with reference to accompanying drawing, wherein with specific embodiment

Fig. 1 illustrates main platform and the anchored buoy that links together;

Fig. 2 illustrates anchored buoy and how to rise to main platform by chain winch;

Fig. 3 illustrates first embodiment of the anchored buoy with connection flexible risers thereon;

Fig. 4 illustrates second embodiment of the anchored buoy with connection steel riser thereon;

Fig. 5 illustrates the birds-eye view that connects in the anchoring rope of anchored buoy;

Anchored buoy dropped to the free-floating position after Fig. 6 was illustrated in and disconnects connection; And

Fig. 7 illustrates from anchored buoy and stretches out and floating pick-up line on the water surface.

The specific embodiment

As depicted in figs. 1 and 2, the illustrated embodiment according to platform 1 of the present invention comprises: main platform 2 and the anchoring arrangement that comprises anchored buoy 3 under water.With as corresponding mode in the patent specification of describing introductoryly, main platform 2 is designed to vertical, basic flat bottomed cylinder.Platform may have circular or polygonal section.

Different with previously known platform, cylinder in this case is provided with the vertical vertical shaft 8 at the center, and the lower end of vertical vertical shaft 8 is suitable for receiving and locking releasedly anchored buoy 3.Platform has at the bottom of two walls being used as ballast box 4 and possible two.They are divided into the case of sufficient amount and guarantee to handle damage stability etc.Be provided with loading tank 5 in ballast box inside and be used for storage of hydrocarbons.Below the living quarters on the main deck 7 18, have engine room and different casees, the case etc. of diving.The equipment, drill outfit and the different ancillary systems that are used for oil and natural gas production are arranged on main deck as module 6.

As depicted in figs. 1 and 2, capstan winch 9 is set at the top of vertical shaft 8, is used for drawing in the connection location that anchored buoy 3 also upwards arrives vertical shaft 8 from submarine site.Anchored buoy has the part cone shape at least, is used to be received in the corresponding tapered segment of vertical shaft bottom.When buoy 3 is in the appropriate location, locked securely by the mechanical locking (not shown).Capstan winch 9 also will be used to platform connect anchoring rope (anchor chain) 10, to anchoring rope (anchor chain) 10 prestress and post-stressing.The connection house steward also has been installed on main platform, has been used to carry well stream, and be used to export oil and natural gas.Delivery hose is installed on and connects house steward and be arranged between the lifter fastener 20 on the anchored buoy.

Main platform 2 may be a passive unit, and it does not have the propelling unit of oneself, and perhaps, if main platform must leave from current location, it must lean on the storeship traction to arrive and leave connection location so.Main platform 2 also may be equipped with a plurality of propelling units (propelling unit) 11, the independent possibility that moves is provided for main platform and need be from the help of storeship.Main platform can oneself move so that avoid atrocious weather or iceberg, and can be with the equipment of oneself homeward and himself is connected with anchored buoy 3.

Anchored buoy 3 is very big buoyancy containers.The unit that the buoyancy container is divided into right quantity does not cause serious consequence to guarantee to damage.The mooring pipe 12 that is used for fixing anchor chain 10 outward flange being provided with of buoy.Anchor chain 10 extends and upward to the chain lock 13 at buoy top from mooring pipe.When the buoy free-floating and when buoy is connected to main platform 2, chain lock will bear all power that come from anchor chain.Lifter and

umbilical cord

14,15 are connected to buoy.If flexible risers 14 is used for normal depth of flow, will I shape or the J-shaped pipe that extend through the buoy shell from bottom to top be set.Lifter 14 is drawn in and is locked in regularly the upper limb of buoy then.To be provided with herein and be used to connection skin 20 safety valve together that is connected by delivery hose etc. etc.The rigid pipe that bellmouth or blocking device are used for fastening bending may be set bottom I shape or J-shaped pipe.If adopt steel suspension wire lifter (SCR) 15, will opening 25 (see figure 4)s be set in buoy central authorities, the deck is set in this case is used to hang lifter.Lifter hangs in the fixing flexible connecting member above deck then.Safety valve, binding flange etc. are arranged on above the deck.Use this set, steel riser will freely hang towards sea bed.Also can adopt similar suspension, be used for freely hanging flexible risers 14.Do not need flexible connecting member at the top.

When erecting stage building 1, main platform 2 and anchored buoy 3 will be connected to each other by mechanical locking.Just as on conventional equipment, drawing in/regulate anchoring rope 10 and tension rope.After drawing in anchoring rope 10, be locked by the chain lock 13 that is arranged at anchored buoy 3 tops.Behind locking anchoring rope/anchor chain 10, the length of having pulled on the chain of ship is put into the anchor chain storehouse 16 at anchored buoy top.At the end of some anchor chains pick-up line 17 has been installed.The quantity of pick-up line 17 depends on how anchoring rope 10 is set.For configuration as shown in Figure 5, adopt three pick-up line 17, i.e. every group of anchoring in the rope 10.Pick-up line 17 is set, make and it is picked up by remote-operated vehicle (ROV), the rope 17 that wherein has buoyancy elements discharges by underwater sound signal, and rope can be picked up at the water surface subsequently, perhaps has a rope 23 equipment floating elements 22 at least so that it is on the water surface and can be picked up.

Drawing in being connected also of lifter, umbilical cord etc. undertaken by connected anchored buoy 3.Behind the

locking lifter

14,15, connection hose and connection cable between the pipe unit on lifter/hawser top and the main platform 2 may be set in place.After anchoring rope 10 and

lifter

14,15 connections, platform 1 prior operation.

As mentioned above, the anchored buoy 3 that is in connection location is locked in main platform 2 by mechanical locking.Before can disconnecting connection, all connection hoses between main platform 2 and the anchored buoy 3 and connection cable must be open circuited.When disconnection had been performed, anchored buoy can separate by opening mechanical locking.Anchored buoy has loaded weight, so that the desired depth D place below the water surface 24 finds balance position.Anchored buoy 3 swims in the position of load that buoy wherein only is subjected to coming from the little degree of wave now.In addition, will reduce to minimum with the risk of the collision on ship and possible iceberg.

When connecting anchored buoy 3, independently or the assistance by storeship, main platform 2 will be brought to the appropriate location of buoy top.Remote-operated vehicle (ROV) is picked up and is picked up rope 17 in the vertical shaft 8 that upwards is raised on main platform 2.Pick up rope 17 and be connected to chain winch 9, chain winch 9 is used for pull-up and is arranged in the end of anchor chain 10 in anchor chain storehouse 16 at the top of anchored buoy 3, and chain is placed on the chain winch.Execution draws in, and wherein chain winch 9 usefulness whole lifters, umbilical cord, hawser of being connected in and extending downward sea bed or the like draw in anchored buoy 3.When anchored buoy 3 was in the appropriate location, it locked by mechanical locking.The connection hose, hawser etc. that come from main platform 2 are connected to anchored buoy 3 and can restart to be produced.

Selectable, to pick up rope 17 and have floating

buoy

21,22,

buoy

21,22 can for example be released by underwater sound signal, or is positioned over the water surface, and can pick up in the mode of routine.If adopt the device that has floating pick-up line 23, rope must be provided with and outwards arrive the side of platform 2 from vertical shaft 8.Floating then rope 23 picks up and is connected in described rope from the side of main platform 2.

Buoyancy elements

21,22 is disconnected and interconnected rope falls into the sea once more.Picking up rope 17 now can be pulled up and pass vertical shaft 8 and be connected to chain winch 9.In addition just as using ROV to carry out pull-up and be connected.

When platform was provided with the equipment that is used for (after oil) drilling well after oil recovery, if this equipment will be arranged on the flat-bed deck 7, this equipment need pass main flat-bed vertical opening (month shape groove).This most suitable employing part loading tank 5 is as a month shape groove.When the moon that adopts " inside " during the shape groove, it is freezing etc. that drilling well lifter etc. prevents to suffer in unsheltered zone.Possible Oil spills also can prevent and overcomes in simple mode in moon shape groove.

Selectively, drill outfit may be arranged on (not shown) on the cantilever platform of main platform 2 sides.Under the situation of drilling operation, can regulate the anchoring rope so that when the weather load variations, keep the flat-bed appropriate location.If platform has been equipped propelling unit 11 in addition, when drilling well, propelling unit can be adopted so that keep the optimum position.

When anchored buoy 3 connects and disconnects, do not relate to drill outfit.After being in latched position, anchored buoy connects drilling well lifter etc.When disconnecting anchored buoy, the drilling well lifter with related valves etc. will disconnect from the bottom, and preferably rises before disconnection and store.

Claims

1. one kind is used for after the drilling well or the floating platform of offshore production hydro-carbon, comprise: surface (7) has the main platform (2) of the semisubmersible of production facilities and/or drill outfit thereon, and the main platform (2) of semisubmersible is designed to vertical, basic flat bottomed cylinder, it is characterized in that: main platform (2) is provided with the vertical vertical shaft (8) at the center, vertical shaft (8) is suitable in its lower end receiving and locks anchored buoy (3) releasedly, and anchored buoy (3) has and is used to the securing device that anchors rope (10) and be used for lifter (14,15) and umbilical cord.

2. floating platform according to claim 1 is characterized in that, anchored buoy (3) has to the small part cone shape, is used for being received in the corresponding tapered segment of vertical shaft (8) bottom on the main platform (2).

3. according to the floating platform of claim 1 or 2, it is characterized in that the mooring pipe (12) that anchored buoy (3) is provided with cable brake (13) and is provided with along the neighboring of buoy (3).

4. according to each the described floating platform among the claim 1-3, it is characterized in that anchored buoy (3) has and is used for flexible risers (14) or steel riser (15) are fastened on device in the central opening (25) on the buoy (3).

5. according to each the described floating platform among the claim 1-4, it is characterized in that, anchored buoy (3) is divided into a plurality of ballast boxs, and each ballast box can partly fill up weight, so that make buoy (3) have proper depth (D) in water after disconnect connecting.

6. according to each the described floating platform among the claim 1-5, it is characterized in that anchored buoy (3) has been equipped Abseiling device (17), make it possible to end with anchor chain (10) and be connected in and on main platform (2), draw in capstan winch (9).

7. according to each the described floating platform among the claim 1-6, it is characterized in that, be used to draw in and strain the capstan winch (9) of anchor chain (10) by employing, anchored buoy (3) can be drawn in the vertical shaft (8) on main platform (2).

8. according to each the described floating platform among the claim 1-7, it is characterized in that main platform (2) has the vertical opening (month shape groove) that is used to carry out drilling operation or the adjusting of other oil wells on the platform shell.

9. platform according to claim 1 is characterized in that, main platform (2) has the cantilever platform that is used to support to be used to carry out the equipment that drilling operation or other oil wells regulate.