Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B19/00—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables
  • E21B19/002—Handling rods, casings, tubes or the like outside the borehole, e.g. in the derrick; Apparatus for feeding the rods or cables specially adapted for underwater drilling
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B35/00—Vessels or similar floating structures specially adapted for specific purposes and not otherwise provided for
  • B63B35/44—Floating buildings, stores, drilling platforms, or workshops, e.g. carrying water-oil separating devices
  • B63B35/4413—Floating drilling platforms, e.g. carrying water-oil separating devices
• • E—FIXED CONSTRUCTIONS
  • E21—EARTH OR ROCK DRILLING; MINING
  • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
  • E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
  • E21B43/01—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells specially adapted for obtaining from underwater installations
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B3/00—Hulls characterised by their structure or component parts
  • B63B3/14—Hull parts
  • B63B2003/147—Moon-pools, e.g. for offshore drilling vessels

Definitions

• the present invention relates to a floating installation in accordance with the preamble in claim 1 below.
• drill and production ships are more vulnerable to wind and waves than platforms. They have a higher centre of gravity and smaller deck space than platforms.
• Fig. 1 shows a section of a drill and production ship seen from above with a dry dock according to the invention when closed and a lifting apparatus according to the invention inside the dry dock.
• Fig. 2 shows a section of a drill and production ship seen from above with the dry dock according to the invention when partly open.
• Fig. 3 shows a section of a drill and production ship seen from above with the dry dock according to the invention when fully open.
• Fig. 4 shows a section of a drill and production ship seen from above with the dry dock according to the invention when fully open and the lifting apparatus according to the invention moved to a position outside the dry dock.
• Fig. 5 shows a section of a drill and production ship seen from above with the dry dock according to the invention when fully open and the lifting apparatus according to the invention moved back into the dry dock.
• Fig. 6 is a sectional view along the line A- A in Figs. 1-5 and corresponds to the situation in Fig. 1.
• Fig. 7 is a sectional view along the line A-A in Figs. 1-5 and corresponds to the situation in Fig. 2 or 3.
• Fig. 8 is a sectional view along the line A-A in Figs. 1-5 and corresponds to the situation in Fig. 4.
• Fig. 9 is a sectional view along the line A-A in Figs. 1-5 and corresponds to the situation in Fig. 4, but with a pipe string connected to the load of the lifting apparatus.
• Fig. 10 is a sectional view along the line A-A in Figs. 1-5 and corresponds to the situation in Fig. 5.
• Figs. 11-18 show an example of operations which can be carried out using the drill and production ship according to the present invention, wherein:
• Fig. 11 shows simultaneous cementing of a casing and handling of the drill assembly
• Fig. 12 shows drilling with the drill assembly
• Fig. 13 shows simultaneous cementing of a casing and lowering of a BOP
• Fig. 14 shows simultaneous lowering of a wellhead Christmas tree and lifting of a BOP
• Fig. 15 shows the installation of the wellhead Christmas tree whilst a completion string with a BOP is made ready
• Fig. 16 shows the installation of a completion string
• Fig. 17 shows test production from one well at the same time as a second well is drilled.
• Fig. 18 shows production from two wells, via moonpools at the side of the main moonpool, whilst another well is drilled.
• Fig. 1 is a schematic presentation of a section of a drill and production ship seen from above.
• the drill ship includes a large central moonpool 1.
• a lifting apparatus 2 is provided in the moonpool 1, and is designed to support a load 3, which, e.g., may be a BOP (blow-out preventer).
• a watertight bulkhead 4 which (as can be seen from Figure 2) consists of two swing doors 5 and 6.
• the bulkhead 4 closes off a compartment 6.
• the compartment 16 is closed off at the bottom by a floor 7.
• a (non-illustrated) pump device is arranged to pump the water in the compartment 16 out, so that in actual fact the compartment functions as a dry dock.
• FIG 6 is a sectional view along the line A-A in Figure 1.
• the moonpool 1 and the bulkhead 4 can also be seen in this figure.
• a derrick 8 Above the moonpool 1 a derrick 8 is arranged, in which there is positioned a lifting device 9.
• One or more pipe racks 15 are positioned on the ship's deck 11.
• the lifting device 2 is seen from the side in Figure 6.
• the lifting device includes a platform 10, on which it is possible to place a load 3.
• the platform is capable of being raised and lowered vertically, to transport the load between the ship's deck 11 .and the compartment 16 of the dry dock.
• the lifting device 2 is horizontally moveable along rails 12 which are secured to the walls of the dry dock.
• the floor 7 of the dry dock is located close to the bottom 13 of the ship, thereby enabling the dry dock to be as deep as practically possible. This means that the dry dock is mostly below the level of the water line 14.
• FIGs 1 and 6 the bulkhead 4 is closed in that the doors 5 and 6 have been swung to the closed position.
• the compartment 16 is emptied of water by means of the non- illustrated pump device.
• a load 3 is made ready, which in the illustrated case is a BOP, on the lifting device platform 10. Since the compartment 16 is now dry, the preparation of the BOP is made easier, because (a) the view from the deck down to the load is improved considerably when the load is dry, (b) there is no need to take into account any danger of water penetration into easily damaged parts of the load 3 whilst it is being made ready, and (c) personnel enter the dry dock and work on the load 3 if the need arises.
• the doors 5 and 6 are opened. Before they are opened, and to make it easier to open the doors 5 and 6, the compartment should be filled fully or in part with water.
• the doors 5 and 6 are partly opened, and in Figures 3 and 7 the doors and swung right against the moonpool 1 walls.
• the lifting apparatus 9 in the derrick 8 has been made ready to receive the load 3, e.g., a BOP.
• the lifting apparatus 2 is now run along the rails 12 into a position outside the compartment 16 and under the derrick 8.
• the lifting device 2 platform 10 may be equipped with a marker (not shown) which is centred under the derrick 8 when the lifting device 2 reaches a predetermined position.
• This position may, e.g., be determined by an end stop switch (not shown).
• the lifting device may be locked in this position to prevent it from moving during the load transfer to the lifting apparatus 9 in the derrick 8.
• the load 3 is connected to the derrick 8 lifting apparatus 9, e.g., via a pipe 17.
• a load When a load is to be brought up from the seabed, it can be transferred to the dry dock. This is done by using the lifting apparatus 9 in the derrick 8 to lift the load 3 up to a position corresponding to the position of the load 3 in Figure 9. The lifting device 2 is then moved out of the compartment 16 to a position corresponding to the position in Figure 9. The load is detached from the derrick 8 lifting apparatus 9 and the lifting device 2 moves the load into the compartment 16. After the doors 5 and 6 have been closed and the compartment 16 emptied of water, e.g., maintenance can be carried out on the load whilst it is in the compartment 16, or the load can be brought up onto the ship's deck.
• the dry dock can also be used without the lifting device, e.g., for launching or taking up a ROV or the like.
• the floor 7 can be removed, by, e.g., drawing it into the ship, so that the whole moonpool can be used for the passage of equipment. This is particularly advantageous if a piece of equipment of large dimensions is to be passed through the moonpool.
• FIGs 11 to 18 show an example of a practical use of the drill and production ship according to the present invention.
• Fig. 11 the cementing of a casing 31 at the well top is about to be completed, at the same time as a drill string 32 with a drill bit 33 is being built up.
• the cementing of the casing 31 is handled by an auxiliary lifting apparatus 34, whilst the build-up of the drill string 32 is handled from the lifting apparatus 9 in the derrick 8. This is made possible primarily because of the size of the main moonpool 1 and the space that is freed in the proximity thereof, as mentioned above.
• Fig. 12 the cementing of the casing 31 is completed and the drilling with the drill string 32 has commenced.
• a BOP (blow-out preventer) 37 is made ready in the dry dock 16 on the lifting apparatus 10.
• the bulkhead 4 is now closed and the compartment 16 has been emptied of water.
• FIG. 13 another casing is cemented, which operation is handled from the lifting apparatus 35 of the derrick, whilst a second auxiliary lifting apparatus 36 is in the process of lowering the BOP 3, which has been made ready in advance on the lifting apparatus 2 behind the watertight bulkhead 4.
• Fig. 14 shows a ready-drilled well 38 on which the BOP 3 is arranged.
• a wellhead Christmas tree 39 is in the process of being lowered down by the auxiliary lifting apparatus 34, whilst the BOP 3 is ready to be lifted by the derrick 8 lifting apparatus 9.
• Fig. 16 the BOP 3 has been lifted into place above the wellhead Christmas tree 39, and a completion string 40 has been run down into the well 38.
• a production string 41 has been run down into the well by means of the auxiliary lifting apparatus 34, whilst the drilling of a new well 42 has commenced using a drill string 43.
• the drill string 43 is suspended from the derrick 8 lifting apparatus 9.
• the production riser 41 will then be tr.ansferred to the smaller moonpools located next to the main moonpool 1, as is shown in Figure 13, so that normal production from the well can be carried out.
• a second riser 46 is also shown, and this is connected to a corresponding moonpool on the opposite side of the main moonpool 1.
• a third well 47 is drilled using a drill string 48, which runs through the main moonpool 1.
• the dry dock may be positioned in a different way in the moonpool and several dry docks could also be arranged in the same moonpool.

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• Engineering & Computer Science (AREA)
• Mining & Mineral Resources (AREA)
• Geology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Mechanical Engineering (AREA)
• Environmental & Geological Engineering (AREA)
• Civil Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Physics & Mathematics (AREA)
• Chemical & Material Sciences (AREA)
• Structural Engineering (AREA)
• Fluid Mechanics (AREA)
• Combustion & Propulsion (AREA)
• Architecture (AREA)
• General Life Sciences & Earth Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Earth Drilling (AREA)
• Farming Of Fish And Shellfish (AREA)
• Artificial Fish Reefs (AREA)
• Structure Of Emergency Protection For Nuclear Reactors (AREA)
• Filling Or Discharging Of Gas Storage Vessels (AREA)

Priority Applications (5)

Applications Claiming Priority (4)

Publications (1)

Family

ID=26648804

Family Applications (2)

Family Applications After (1)

Country Status (5)

Cited By (3)

Families Citing this family (11)

Citations (3)

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• 1998
  • 1998-03-06 NO NO980987A patent/NO980987D0/no unknown
  • 1998-12-10 WO PCT/NO1998/000374 patent/WO1999029566A1/en active IP Right Grant
  • 1998-12-10 GB GB0013258A patent/GB2347387B/en not_active Expired - Fee Related
  • 1998-12-10 KR KR1020007006330A patent/KR20010032981A/ko not_active Application Discontinuation
  • 1998-12-10 AU AU17893/99A patent/AU1789399A/en not_active Abandoned
  • 1998-12-10 GB GB0013252A patent/GB2346844A/en not_active Withdrawn
  • 1998-12-10 KR KR10-2000-7006329A patent/KR100535369B1/ko not_active IP Right Cessation
  • 1998-12-10 AU AU17892/99A patent/AU1789299A/en not_active Abandoned
  • 1998-12-10 WO PCT/NO1998/000373 patent/WO1999032352A1/en not_active Application Discontinuation

Patent Citations (3)

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