CA1185800A - Method and apparatus for constructing an artificial island - Google Patents
Method and apparatus for constructing an artificial islandInfo
- Publication number
- CA1185800A CA1185800A CA000439148A CA439148A CA1185800A CA 1185800 A CA1185800 A CA 1185800A CA 000439148 A CA000439148 A CA 000439148A CA 439148 A CA439148 A CA 439148A CA 1185800 A CA1185800 A CA 1185800A
- Authority
- CA
- Canada
- Prior art keywords
- tanker
- water
- hull
- oil well
- tankers
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02B—HYDRAULIC ENGINEERING
- E02B17/00—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor
- E02B17/02—Artificial islands mounted on piles or like supports, e.g. platforms on raisable legs or offshore constructions; Construction methods therefor placed by lowering the supporting construction to the bottom, e.g. with subsequent fixing thereto
Abstract
ABSTRACT OF THE INVENTION
This invention is directed to a novel method and apparatus for constructing artificial islands in relatively shallow bodies of water such as lakes, seas and oceans for use in drilling oil and gas wells and installing storage and production platforms. The method of building an artificial island in a water-bound area comprises converting an oil tanker, oil/bulk/ore, or oil/ore (O, O/B/O, O/O) hull so that it can be partially submerged by liquid or solid ballast; transporting the hull to the water-bound area where the artificial island is to be created; and partially submerging the hull with liquid or solid ballast so that the bottom of the hull is founded on the bottom of the water body, while a portion of the hull remains above the water level. The apparatus capable of forming a temporary or permanent artificial island in a relatively shallow body of water comprises a tanker vessel, and means on the vessel for taking on ballast in the hull thereof to thereby partially submerge the vessel so that is rests on the bottom of the water body while the deck of the hull remains above water.
This invention is directed to a novel method and apparatus for constructing artificial islands in relatively shallow bodies of water such as lakes, seas and oceans for use in drilling oil and gas wells and installing storage and production platforms. The method of building an artificial island in a water-bound area comprises converting an oil tanker, oil/bulk/ore, or oil/ore (O, O/B/O, O/O) hull so that it can be partially submerged by liquid or solid ballast; transporting the hull to the water-bound area where the artificial island is to be created; and partially submerging the hull with liquid or solid ballast so that the bottom of the hull is founded on the bottom of the water body, while a portion of the hull remains above the water level. The apparatus capable of forming a temporary or permanent artificial island in a relatively shallow body of water comprises a tanker vessel, and means on the vessel for taking on ballast in the hull thereof to thereby partially submerge the vessel so that is rests on the bottom of the water body while the deck of the hull remains above water.
Description
I
PILED OF THE INVENTION
This invention is directed to a novel method and apparatus for constructing artificial islands in relatively shallow waters. More particularly, this invention it directed to a novel method and apparatus for constructing artificial induce in relatively shallow bodice of water such as lake r seas and ocean for use in drilling oil and gay wells and in~tallin4 storage and production platform.
BACKGROUND OF THE INVENTION
In recent years, with mankind' 5 increasing and continuous reliance upon hydrocarbon fuels and products, and the depletion ox exiting oil field on land in the western hemi~phsr~, extensive and costly efforts have been made to locate petroleum deposits that underlay the floor of various large bodies of water such as lakes, seas and oceans. In North America, substantial oil and gas well drilling activity has taken place in the Beau fort Sea, which is in the Arctic Ocean north of Alaska and the northern territorial of Canada.
Petroleum geologists generally believe that several of the sedimentary geological formations located below the floor ox the Beau fort Sea contain large deposits of petroleum material.
I being in a polar region, drilling oil and gas wells in the effort Sea it hazardous and extensive ope~atlon. ambient temperatures are Qxtremoly low during the wintertime. Moreover, tremendous pressures are generated against the drilling station by polar ice.
One of the methods used in the effort Sea in \
(3 preparation for drilling an oil well is to build an artificial island at the location where the well is to be drilled, The material for such islands is dredged from the sea floor and piled in one location until the surface of the island is above the water and is level.
Substantial erupt to date has been concentrated in the Canadian sector of the Beau fort Sea where the explore-lion procedure has followed two main patterns. In relatively shallow water, up to about 19 eaters, drilling has been a winter operation from artificial sand islands formed the previous summer by dredging and dumping from barges. In deeper water, from 25 to 68 metros, drilling has been a summer operation using drill-shipaO
Sand deposited under water tends to take up a very flat edgy slope of about 7 to 8 percent with the result that artificial islands in water deeper than about 10 Metro consume huge quantities of sand and are hence very expensive to construct. In order to overcome this problem, a caisson-retained island has been developed whereby the upper portion of the sand is retained by a ring or collar of caissons. These are founded on an underwater pad of dredged sand about 10 meres below sea level. Dome Petroleum, a large Canadian company which it actively searching for oil in the Beau fort Sea, completed a concrete caisson-retained island in the fall of 1981. Essay Resources is presently proceeding with the construction of a tensioned-steel Cowan retained island.
Numerous procedures and apparatus for drilling oil wells in the formations below water bodies have been proposed. Some of these procedures and apparatus are disclosed in the patents listed below: -patent No. Issue Date Inventor US. 2,472,869 June 14, 1949 Traverse
PILED OF THE INVENTION
This invention is directed to a novel method and apparatus for constructing artificial islands in relatively shallow waters. More particularly, this invention it directed to a novel method and apparatus for constructing artificial induce in relatively shallow bodice of water such as lake r seas and ocean for use in drilling oil and gay wells and in~tallin4 storage and production platform.
BACKGROUND OF THE INVENTION
In recent years, with mankind' 5 increasing and continuous reliance upon hydrocarbon fuels and products, and the depletion ox exiting oil field on land in the western hemi~phsr~, extensive and costly efforts have been made to locate petroleum deposits that underlay the floor of various large bodies of water such as lakes, seas and oceans. In North America, substantial oil and gas well drilling activity has taken place in the Beau fort Sea, which is in the Arctic Ocean north of Alaska and the northern territorial of Canada.
Petroleum geologists generally believe that several of the sedimentary geological formations located below the floor ox the Beau fort Sea contain large deposits of petroleum material.
I being in a polar region, drilling oil and gas wells in the effort Sea it hazardous and extensive ope~atlon. ambient temperatures are Qxtremoly low during the wintertime. Moreover, tremendous pressures are generated against the drilling station by polar ice.
One of the methods used in the effort Sea in \
(3 preparation for drilling an oil well is to build an artificial island at the location where the well is to be drilled, The material for such islands is dredged from the sea floor and piled in one location until the surface of the island is above the water and is level.
Substantial erupt to date has been concentrated in the Canadian sector of the Beau fort Sea where the explore-lion procedure has followed two main patterns. In relatively shallow water, up to about 19 eaters, drilling has been a winter operation from artificial sand islands formed the previous summer by dredging and dumping from barges. In deeper water, from 25 to 68 metros, drilling has been a summer operation using drill-shipaO
Sand deposited under water tends to take up a very flat edgy slope of about 7 to 8 percent with the result that artificial islands in water deeper than about 10 Metro consume huge quantities of sand and are hence very expensive to construct. In order to overcome this problem, a caisson-retained island has been developed whereby the upper portion of the sand is retained by a ring or collar of caissons. These are founded on an underwater pad of dredged sand about 10 meres below sea level. Dome Petroleum, a large Canadian company which it actively searching for oil in the Beau fort Sea, completed a concrete caisson-retained island in the fall of 1981. Essay Resources is presently proceeding with the construction of a tensioned-steel Cowan retained island.
Numerous procedures and apparatus for drilling oil wells in the formations below water bodies have been proposed. Some of these procedures and apparatus are disclosed in the patents listed below: -patent No. Issue Date Inventor US. 2,472,869 June 14, 1949 Traverse
2,589,153 March 11, 1952 Smith 2,939,290 June 7, 1960 Craze Tao Feb. 28, 1961 McLean 104,037,424 July 26, 1977 Angers 4,080,7~B March 28, 1978 Reusswig et at.
4,118,941 Oct. 10, 1978 Bruce Cdn.470,212 Dec. 19, 1950 Traverse 966,320 April 22, 1975 Guy ~71,758 July 29, 1975 Best 1,963,817 Oct. 9, 1979 Coachmen 1,066,900 Nov. 27, 1979 Bennett The basic theme of most of these references is to provide artificial islands or operation sites in water bodies such as the Beau fort Sea or the Gulf of Mexico for the purpose of supporting equipment such as drilling rigs engaged in searching for petroleum deposits below the water body floor. Current techniques for building islands cost in the hundreds of millions of dollars and usually consist in part of dredging solid matter from the water body f loon and heaping it to thereby provide a foundation of earth material upon which can be situated various type of hardware such as submerged barges or caissons, the tops of which ultimately penetrate the surface of the water body. In moms kiwi, to reduce slump, the idea of the land are supported with a retaining member such a a wall or caisson.
SUMMARY OF THE INVENTION
The present invention lo directed to a eddy and apparatus for constructing an artificial island by taking atr0noth~ned oil tanlcers, oil~bulk/ore or oil/ore tankers, transporting them to ohs diehard sites, either under their own power or by wowing, and partially sub-merging the hulls, with awry and waler ballast dredged from the Roe floor, The hulls can be used individually or in combination. The concept of Herb the flexibility of providing a movably drilling island, which can ha achieved in a relatively short lima by partially submerging the hull or hull, conducting the desired operation such as drilling an oil well, and then when completed, refloating the hull and transporting it to a new site. Alternatively, the partially submerged hull can be left in place to form a production or Tory platform The bow(s) of the substantially submerged hull B) would normally be pointed in the direction of the prevailing winds, WOW and ice action for the area.
The invention it directed to method of forming tubule drooling production or Atari facility in a relatively shallow hvdy of water which may be contested with ice or other objects comprising: con~tructlng a vessel which can float or be partially submerged by taking on liquid or solid ballast and of sufficient ma and strength to provide tabulate for oil well drilling, production or storage operations, and movement resistance against wave, ice and other objects equipping the vessel with a drilling rig and a drill stem and production cawing protector-rstainer located below the drilling rig, the protector-rQtainer extending downwardly from about the base of thy drilling rig or produc~lon facility to the bottom of the vessel;
importing the vessel to the water or ice bound area where thy drilling or production platform it to be lotted and submerging the vessel with liquid or solid ballast 80 that the buttock... of the vessel it founded on the bottom of the water body, or on a pad formed on the bottom of the water body, while the deck remains above water, the protector-re~ainer protecting drill stem and oil well production casing from interference by ice, wave or other object and restraining any fluid produced during drilling or operation of an oil well from string the surrounding body of water.
The method may include drilling an oil well into the floor of the water body while the partially submersed hull it founded on the bottom of the water body The hull may be refloated after being partially merged by removing ballast from the interior of the partially submerged hull.
I the oil jell experiences a blow-out during the drilling thereof, the curds oil it dlrec~ed into the $nterlor ox the partially submersed hull to prevent contamination of the water body. The oil direction can be automatic or by jump. A Rowley well may be drilled prom the ~ar~lally submerged hull while the oil well it experlenGin~ blow-out. Thy towered oil can by burnt off or hauled away.
In the method, protective barrier may be cons~ructad alongside By eye one wide of the partially submerged hull by drudging solid material from the water body floor and heaping it alongside thy partially submerged hull. Thy artificial island may be formed by two partially ~ubmarged ship hulls. The two partially submerged hull may be arrayed 3ide-by-side in parallel adjacent manner.
A protect barrier may be constructed alongside at least one wide of the partially submerged hull by dredging solid material from the water buddy floor and heaping it alongside the partially submerged lo hull which I arranged in V-pattern with another partially submerged hull. The protective barrier - aye -! g conY~ructed alongside at least one lye of the partially ~ubmarg~d hull may be formed by dredging solid and liquid material from the water body floor and phrasing the dreaded material, before duping the frozen material on the waler body floor alongside ha partially submersed hull.
A protective barrier may be ¢onstructad along-side at least one side of thy partially submerged hull by dredging solid and liquid material from the water lo body floor, duping the dredged material on the our-face of ice surrounding the partially submerged hull thereby sinking thy ice and the dredged material onto the water body floor. The dredged material is allowed to freeze prior to submerging, tarrier protection for the partially submerged hull may Allah be created by partially submerging it Lotte one ship hull 80 thee it projects radially from the main partially submerged hull. A plurality of ship hull on a radially deposed pattern may be placed around the c1rcumfer~nce of the main partially ~ubmergad hull. This is useful when the main hull us left in place a production or Tories platform.
The invention it directed to a movable oil well drilling and production structure capable of forming in a relatively Lowe body ox water which may be contested with ice and other objects a temporary or permanan~ water bDtto~ founder oil well drilling, production or storage facility comprising: a vessel capable of being at least partially aubmercJed to ret on the bottom ox the body of water or on a peal constructed on the bottom of the water body and of ~ufficiant mast and ~trenyth to provide stability for oil well drilling, production so storage operation and movement r~sl~tance again waves ice and other object; an oil wall drilling rip, production or Turks facility carried by the vowel and D protaçtor-retainer located under the drilling fig or production facility and extending downwardly from byway the bate of ha drilling rig or ~roductlon solute to the bottom of ho vessel Jo that when thy visual it founded on the bottom of the body of worry or on the pad, the protector-retainer prO~eCtB
drill to and oil well production cawing from interference by ice, wave or other ox jacket, and restrains any fluid produced during the drilling or operation of the oil well from entering the surrounding body of waxer.
I
- 6 ( a The vessel may include means for ejecting ballast from the interior of the hull to thereby refloat the partially submerged visual. The vessel may be self-propelling The vessel may have an oil well drilling rig mounted on the deck of eye hull. The vessel may also have a monopoly (an oil retaining cavity) built into part of the interior of` the hull below the drilling rig The hull of the vessel may be mounted on top of a second whip hull to provide a double Decker hull. The vessel may have two oil well drilling rigs moLInted on the deck of the hull and two monopoly built into the interior of the hull, one below each drilling rig.
Normally, the second monopoly would be at a reasonable distance prom the first monopoly In zones where the water body floor is mainly clay-like in character, refloating may become a problem due to suction created at the bottom of the vessel. In order to overcome this suction action, it might be desirable to install a number of pipes in the bottom of the hull or lnje~ting air or water at suitable pressure thereby relieving the suction force. In certain Sue-Sheehan, to withstand extreme lateral forces ho increasing the overall specific gravity of the submerged vessel, it may be necessary to use iron ore pellets as ballast instead of sand or the like no withstand ice pressures, and the like, the hull can be strengthened by using heavy steel cross-struts, inter-rib reinforcing. Alternatively or in accompaniment t the spaces between the frame members of the hull can be filled with concrete and steel rein-for cement. The rudder and propeller of the vessel can be protected within a housing formed in the vessel body so that the propeller and rudder can be used repeatedly as the vessel is submerged for a time, refloated and moved to a new site and then submerged again prior to drilling a the new site.
To prevent freezing of ballast waxer, such freezing bring capable of damaging the hull body, by expansionary ice force, insulation Jo reduce heat loss from the interior of the hull can be installed, or the ballast water can be heated by sore suitable economical means. The vessel can be equipped with its own dredge in, sand and water pumping equipment so that it is self-reliant.
DRAWINGS
In the drawings.
FIGURE 1 represents a perspective view of a tanker converted for use as an artificial island and drilling platform FIGURE 2 represents a perspective view of two hulls, one above the other, converted for use as an artificial island and drilling platform;
FIGURE 3 represents a side elevation view of the double Decker hull with a drilling rig erected in place over a monopoly in the hull;
FIGURE 4 rcprcscnts an end elevation view of the double Decker hull;
FIGURE 5 represents a side elevation view of the double Decker hull supporting two drilling rigs, one rig for drilling the primary oil well and a second rig for drilling a second oil will or a relief well;
FIGURE 6 represent a side elevation view of the two rig double Decker hull combination depicted in FIGURE 5 above, illustrating the manner in which a relief hole it drilled to intersect with the main drilling hole, FIGURE 7 represents a plan view of a converted hull equipped with two Minneapolis for dual fly drilling capability FIGURE 8 represents an end elevation view of the hull depicted in FIGURE 7 above resting on the sea floor;
FIGURE 9 represents a plan vie of two converted hulls placed in parallel aligned position;
FIGURE 10 represent an end elevation view of the twin hull depicted in FIGURE 9 above;
FIGURE 11 represent a plan view of a hull converted according to the invention, together with a dual-direction conveyor belt arrangement which can be utilized for manufacturing protective ice-earth debris and dumping it alongside the hull to provide a submerged protective barrier for the hull;
FIGURE 12 reappearance a front elevation view of the ship hull depicted in FIGURE 11 above, illustrating the manner in which debris it placed on either side of the hull to provide a projection barrier for the hull;
FIGURE 13 represents an end elevation view of a pair of converted double Decker hulls placed in parallel adjacent alignment with one another;
IRE 14 represent a plan elevation view of a hull equipped with bottom debris pumping and spraying equipment for use in spraying sand and soil onto the ice perimeter surrounding the hull;
FIGURE 15 represents a plan elevation view of a converted hull which may be detached in thy mid-region to provide an artificial drilling island comprising the two detached portions of the hull arranged in parallel adjacerlt positions FIGURE 16 represents a plan elevation view of two adjacent aligned converted hulls, surrounded by reinforcing barrier debris and a plurality of radially disposed tanker Howe around the perimeter of the barrier;
FIGURE 17 represents a plan elevation view of two converted hulls arranged to provide a wedge arrange-mint for withstanding ice and wave forces;
FIGURE 18 represents an end elevation Al view ox the two Howe described in FIGLlRE 17 above;
2Q FIGURE 19 reprint a plan view of the manner in which four converted hull can be utilized to provide a protective whip harbor;
FIGURE 20 represents a plan view of the manner in which two converted hulls can be arranged in end to end relationship to provide an aircraft landing strip FIGURE 21 represents a side elevation view of a twin hull design pitted with a new bow section FIGURE 22 represents a plan elevation view of a twin hull design fitted with a new boy section;
FIGURE 23 reprint a side elevation view of a twin hull design fitted with a new bow section and a gunwales height extension;
FIGURE 24 represents a plan elevation view of a twin hull design fitted with a new bow section and a gunwales height extension;
FIGURE 25 represents a side elevation view of a double Decker twin hull combination design, with the lower twin hulls fitted with a new bow section;
FIGURE 26 represents a plan elevation view of a double Decker twin hull combination design, with the lower twin hulls fitted with a new bow section.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGURE 1, a ship hull I accord-15 in to one aspect of the invention, is equipped with and carries a drill rig 4. The hull is shown located in a large body of ice 6. While not shown, the bottom of the I
- AYE -Sue hull 2 rests on the bottom of the body of water support-in the ice 6. The drill rig 4 is positioner towards the stern of the hull 2 ahead of the wheel house 8. The bow of the hull carries a heliport 12 which serves as a landing pad for a helicopter 10. The helicopter 10 serves to provide 8uppl it for operation of the hull-drill rig assembly. The hull 2 is suitable for opera-lion in water of about 20 meres depth. This leaves about 5 Quoter of freeboard.
FIGURE illustrates the manner in which, according to another aspect of the invention, one hull 14 is positioned above and secured to a second hull 16 in double Decker manner. This double Decker hull combination enables the hull-rig combination to operate in deeper waters than the single hull version, for example, waters of about 45 metros depth.
The double Decker hull arrangement as shown in FIGURE 2 can be manufactured in a number of ways. One possible way it to clean away the normal cock e~luil~ment on a hull, sink the hull with suitable ballast, move second floating hull into position over the submerged hull, and then secure the two hulls together by suitable bracing such as steel beams, welding and the like.
Wedges must be inserted in the tapered spaces that normally exit between the deck of the underlying hull and the bottom of the superimpose hull to offset the lateral camber ousto~arily built Unto the fleck of the underlying hull.
Normally, in Arctic waters. such as the Beau fort Sea, either the single hull or douhle-decker hull design, when founded upon the floor of the water-body, should be oriented with its bow facing to the northwest into the direction of prevailing winds, waves and ice migration prevalent in those areas. Even so, in some locations, a wave deflector may be required along one side to increase freeboard and limit the volume of water token on deck from maximum broadside waves.
FIGURE 3 represents a side elevation view of the double Decker hull design depicted in FIGURE I The upper hull 14 is secured Jo the lower hull by welding cables, steel reinforcement, and the like. As can be teen in FIGURE 3, the drill rig 4 is positioned above a monopoly 18 which extends vertically prom the fleck of the upper hull 14 through the two hulls, to the bottom of the lower hull 160 The monopoly 18 is an enclosed cavity open to the atmosphere with overflow drains into the hull or hull compartments. As can be seen in FIGURE 3, the drill rig 4, by being positioned above the monopoly 18, can raise and lower drill stem 20 through the monopoly 18 into the scabbed below the bottom of hull 16 for drilling in the manner of a conventional oil well.
A very significant advantage of the moon-pool 18 design is that if there it a blow-out of the well being drilled, the crude oil that is blown out can be initially contained within the confines of the moon-pool 18 and then directed into the hull or compartments thereby completely preventing pollution in the delicate environment of the Arctic. If the blow-out is extensive and long lasting, the escaping crude can be directed automatically or pumped into the sizable compartment in the upper hull 14 and the lower hull 16. The capacity of these two hulls, even if partially taken up with ballast, it significant and can in most cases contain four to six months "wild" production from the well.
FIGURE 4 shows an end elevation view of the double Decker hull design including the upper hull 14, the lower hull 16 and the monopoly 180 FIGURE 4 also illustrates the wedges 22 which are welded or secured in place between the upper and lower hulls in order to off-set the camber of the deck of the lower hull 16 and provide a stable secure fit between the upper hull 1 and the lower hull 16.
As FIGURE 5 demonstrates, the double Decker lo hull design can be fitted with two drilling rigs 4 and I In such a case, the ship is also fitted With two Minneapolis 18 and 26 respectively. The second rig 24 can be used for drilling a relief hole to intersect with the main hole being drilled by rig 4 if for sore reason, such as a blow-out or a collapsillg formation, it icky necessary to interconnect with the first hole. The auxiliary rig 24, rather than acting as a relief mews-urea can be used to drill a second hole at the same time that the first hole is being drilled The direction of the two hole can be diverged by means of directional drill bit. This tandem arrangement can be important in areas where the drilling season is short.
FIGURE 6 illustrates in side elevation view the manner in which a relief hole 28 can intersect with Jo main hole 30 utilizing the dual rig arrangement, fig 4 and rig 24, discussed above.
FIGURE 7 illustrates in plan elevation view a typical single hull 32 with two Minneapolis 34 and 36.
FIGURE 8 illustrates in end elevation Al view the manner in which a berm 38 may be built up on one side of hull 32. Alternatively, the berm 3Q allows reduced ballasted weight on relatively weak soils err the depth of such toils make it impracticable to remove them.
FIGURE 9 depicts in plan elevation view a twin-hull alignment that can be utilized where the sea bed soil is weak or where the predicted ice or wave forces may be greater than can reasonably be endured by a single hull. the parallel arrangement of the win ship 40 and 42 immediately doubles the lateral no instance for the same effective ballasted weight, Alternatively, this win hull arrangement can allow a reduced ballasted weight on relatively weak soil of low stability where the extensive depth of such soils makes it impractical to remove them. FIGURE 10 demonstrates in end elevation view the twin hull concept 40 and 42, and thy manner in which the two hulls are founded on the sea-bed.
FIGURE 11 illustrator a system which can be u~2d for manufacturing solid debris for distributing along the yea floor to build-up a protective barrier along the sides ox the vessel 46. The vessel shown has two Minneapolis 48 and 50. The system consists of a suction line 52 which has one end resting on the sea floor. The line 52, by means of suction exerted by Bud and sand pump 54, or the like, draws up clay, sand, sea water, and other solid material from the sea bottom and deposits it on a tony moving conveyor 56 which extends substantially the length of the vessel 46. The solid water mixture deposited on the conveyor 56, when ambient temperatures are well below freezing such as in the Arctic during the winter, freezes into a solid mass as it is conveyed along the conveyor 56. At the end of 10 the conveyor 56, away from pump 54, the solid material is deposited onto an adjacent conveyor 58 which runs in a direction parallel with and opposite to conveyor 56~
Conveyor 56 is normally located at the edge of the hull of the vessel 46. By means of a mechanical arm or manual power, or the like, the frozen solid debris traveling along conveyor 58 can be broken into lumps which are then pushed over the side of the vessel so as to wink to the bottom of the water body. In this way, a barrier of idea material, which should remain in frozen condition for a significant length of time, can be built up alongside the submerged hull of the vessel 46. Thus provides valuable protection for the hull 46 against lateral pressures exerted by waves and ice. The system described can be utilized for depositing a similar barrier along the opposite side of the hull 46. To slow down thawing of the frozen debris once it has been deposited in the sea waxer, cedar bark or other cheap, available coarse material with insulating qualities can be incorporated in the debris while it is hying frozen.
30 Such material can be carried into the vessel's hold initially or be brought to the site in a supply ship or the like.
FIGURE 12 depicts in an end elevation view the method whereby debris 60 and 62 can be built up along each ire of the vessel 46.
FIGURE 13 represents in end elevation view a combination of vessel hulls which can be achieved by combining the twin-hull concept of FIGURE 9 with the double Decker hull concept of FIGURE 12~ This combination can be utilized in areas where the water depth is in the range 20 to 45 metros and excessive ice and wave action pressures are encountered, thereby requiring extra stability.
FIGURE 14 in plan elevation view illustrates a lo system whereby suction pumps in combination with suction lines which draw solid and liquid material from the sea-bed can be utilized for pumping and spraying sand, silt and other bottom material onto the ice surface surround-in the vessel 68. The Betty material is allowed to Roy to by contlguou~ with the ice. Eventually, with build-up, the heavy weight of the solid material pumped onto the ice around the perimeter of the vessel 68 Jill submerge the ice whereupon everything will sink to the yea bottom In this way, with repeated build-up of ice, 25 and depositing of sand and debris onto the surface of such fillip ice, an effective ice-solid barrier wall can be built up around the perimeter of the vessel 63.
FIGURE lo shows in plan elevation manner a split hull design which can be detached at its mid-region and the two separate hulls placed alongside one another in parallel manner to provide a twin hull con-figuration as illustrated above in FIGURE 9.
FIGURE 16 illustrates in plan elevation view a system that can be used for reinforcing an artificial island created by a twin hull combination, and a harrier reef built up around the periphery of the twin hulls, to withstand for a long period of time extremely severe ice and wave forces emanating from any direction. A number of hull, ten are shown, ballasted so that they sink to and rest on the sea floor, are arranged in radial pattern around the circumference of the twin hull-surrounding barrier island combination. The ballasted hulls that are arranged radially should have their noses the ends of the hull remote from the twin hull-barrier combination) cut down, sloped downwardly, or submerged below the ice level on the water/ so that any ice what may contact the nose of those hulls will tend to ride up on the hull, and translate the forces downwardly.
This is preferable Jo having the ice Inset the noses I head-on and thereby impart the forces through the hulls directly onto the peripheral barrier protecting the twin hulls. Preferably, the radially disposed partially sub-merged hulls are initially ballasted with large objects such as rocks and the like and transported partially I submerged to the site. Rocks are preferred so that if any holes are punched in the Howe by ice, the ballast will not wow out through the hole onto the sea floor, thereby losing e~fec~ivenea3 as ballast. ennui no longer of use, the holes can be sealed, the hull refloated and transported.
FIGURE 17 illustrates a variation of the twin hull concept illustrated in FIGURE 9 whereby two hulls 70 and 72 are arranged in a Y pattern (inverted in FIGURE 17~. The point of the V faces the direction of prevailing wind, ice and waves The space between the arts of the V are filled with sand, solid debris and the like in order to prevent the two Veranda hulls from being forced to move under the pressure from ice and waves. FIGURE 18 illustrates in end elevation view the manner in which the V-arranged hulls are founded on the sea floor.
FIGURE 19 illustrates in plan elevation view an arrangement of three hulls, together with a shorter ship hull, to provide a protected harbor area for a supply ship or a production transportation ship for a well which has been drilled in hostile waters such as the Arctic Ocean, Three of the vessels 74, I and 78, are arranged so that their respective boys or sterns intersect to provide a generally "U-shapedi' configure-lion. The pen end of the "U" is partially closed by means of a vessel of shorter length 80. The supply ship 82 can enter and leave the protected area formed by the linked vessel arrangement through the opening exist-in between vessels 78 and 80.
FIGURE 20 illustrates the manner in which two vessels 84 and a may be arranged in end to end align-mint BY as to form a long surface which can be converted into a runway for aircraft. Normally, two vessels arranged in this manner should be of sufficient length to provide a landing and takeoff area for transport aircraft such as Hercules or Caribou aircraft.
FIGURES 21 and 22 illustrate an embodiment of the invention wherein two hulls 90 and 92 ore arranged side-by~side, in parallel alignment, in twin-hull pattern, the combination being it'd with a new bow section 94. A rig 96 is mounted at the fore of hull 92 and optionally a relief rig 98 can be positioned at the aft section of hull 900 FIGURES 23 and 24 illustrate a further embodiment of the invention wherein two hulls 100 and 102 are arranged in twin-hull pattern, the combination bring fitted with a gunwale height extension 104 and a new bow suction 1060 A rig 108 is mounted at the fore of hull 102 and optionally a relies rig 110 can be positioned at the aft section of hull 100~
Flyers 25 and 26 illustrate a further embodiment of the invention wherein two hulls (one hull I identified a 112 while thy skin cannot by Zen in either FIGURES 25 and 26) are arranged in twin-hull pattern while a second pair of hulls 114 and 116 are superimposed in double Decker twin-hull pattern upon the underlying twin hulls 112 and the unseen hull. A new bow section 118 it fitted at the front ox the lower twin hulls. A new tern section 120 is fitted at the rear ox the upper twin hull 114 and 116. Drilling rig 1~2 and optional relief rig 124 are mounted on the upper twin decks. This configuration provides double height and double lateral stability.
- 19~
The predominant force is from ice and the maximum lateral force on the vessel founded within the land fast ice, including wind and current forces, may amount to as much as 118,000 tones. The effective submerged weight to resist lateral movement will depend upon sea-bed conditions buy it likely to average about 236,000 Tony for the single ship hull concept.
While a bottom sea depth of about 20 metros is feasible for the jingle converted hull configuration, if drilling it to be conducted in waters deeper than about 20 metros, then in place of the double-deck~r hull design, if required, a sand-base or rock-base island can be built up to within a depth of 20 metros below the high waxer mark end the jingle hull design founded on what island.
The single or double Decker hull concept pro-vises a relatively inexpensive movable drilling island which, in the short time available in Arctic regions, can be advantageously moved by towing or self-propulsion to a prospective drilling site, sunk so that it rests on the sea floor by use of permanent and temporary ballast, and then Atari a well is drilled (typically 90-180 days), be refloated and moved to a new drilling site.
In this way, the jingle or double Decker hull concept provides the possibility of drilling two oil well holes per year in different locations, one typically in the winter, the second typically in the summer. In an average year, with some ice breaker assistance, it - 19~ --should be possible to refloat and transfer the rig-vessel to a now location in June or July of each year.
During period when the seas are generally calm, the sinking of the hull to the sea bed will be a relatively easy operation. When water are rough and lateral forces from ice pressure prevail, sinking the hull to revs on thy sea bottom will require more bottom preparation and care.
The depth to which a vessel may be sunk as a grounded drilling island will depend on the freeboard required in relation to the extreme peak wave heights on the bow and sides of the hull. Considerable water and spray may be accepted over the deck surface and drained way through suppers during extreme wave action.
Alternatively, wave and spray deflectors can be built along the sides of the hull to increase the effect of freeboard. Ideally, temporary ballast used to submerge the hull should be in the form of sea water so that it can be easily pumped out prior to moving at a new site.
However, send and other heavier material will sometimes be used for temporary ballast in order to provide increased stability to the hull when founded on the sea bottom. To refloat the hull, the sea water used as ballast may by pumped out. If sand ballast is used, it may he necessary to remove the sand by solve suitable jeans before sufficient buoyancy of the hull can be achieved to refloat the visual A complicating factor in areas where the sea bottom it mostly clay is the possibility of strong suction forces being exerted on the bottom of the hull. To overcome this, it may be desirable to install a number of small pipes to the bottom of the hull (preferably outside the hull) for injecting air or water at suitable pressure into the interface between the clay Betty and the keel ox the hull. Alternatively, a sand bed can be put down prior to founding the hull on the bottom to prevent suction problems.
To withstand the substantial external ice and wave force, the hull must typically be strengthened.
One method may involve adding additional vertical steel members between the main frames to withstand the ice forces over the range of height in which they would act.
A second alternative may be to fill between the main frames with concrete and additional steel reinforcement a required.
To protect the propeller and rudder of the vessel from ice damage, and She like, the propeller area of the vessel should be protected. This may include housing the propeller in a suitable housing that is sufficiently strong to wlth~tand the substantial ice pressures that might be exerted.
To prevent damage to the interior of the hull that might occur due to freezing of ballast water and the like within the hull at portions of the hull that remain above the water level, insulation to reduce heat 105g or ballast heating water means may be used.
Waves acting on the ship will cause scour erosion to the water body floor supporting the vessel and suitable scour protection should be used. However, in Arctic waters, this scour time will usually be fairly I
short, that is, from the time of founding of the vessel upon the sea bottom to freeze up. Thus, if the vessel is founded on cohesive material or if limited scour can be tolerated, scour protection may not be required.
S Sand berms or submerged frozen blocks can be provided alongside thy hull to provide passive resistance or to increase the path of foundation failure.
The exact requirements for foundation treat-mint and scour protection will Append on the local sea-bed conditions and depth of urea specific to each site. Geotechnlcal investigations of the proposed site should be carried out in advance in order to prepare a proper design for foundation treatment and make plans or all necessary materials and equipment.
The V arrangement of two ships us illustrate in FIGURES 17 and 18 has two possible advantages:
(a) It allows a wedge of sand to be placed in a protected area between the two vessels for increased lateral ruttiness; and (b) It allow the possibility of having the main and emergency drilling wells placed on separate vessels Father than having two Minneapolis on one vessel) and thereby provide an alternative safety procedure in the event of blow-out or fire Temperature, Precipitation and Visibility Typical weather summaries c3enerated from station in the euphoria Sea area provide the following general data:
(1) Extreme low temperatures occur from December to March inclusive and range from -42~C to -50C. Mean daily temperatures during the same months range from -25C to -30DC~
( 2 ) Mean wind speeds do not vary greatly throughout the year but tend to be least in February and greatest in September and October.
4,118,941 Oct. 10, 1978 Bruce Cdn.470,212 Dec. 19, 1950 Traverse 966,320 April 22, 1975 Guy ~71,758 July 29, 1975 Best 1,963,817 Oct. 9, 1979 Coachmen 1,066,900 Nov. 27, 1979 Bennett The basic theme of most of these references is to provide artificial islands or operation sites in water bodies such as the Beau fort Sea or the Gulf of Mexico for the purpose of supporting equipment such as drilling rigs engaged in searching for petroleum deposits below the water body floor. Current techniques for building islands cost in the hundreds of millions of dollars and usually consist in part of dredging solid matter from the water body f loon and heaping it to thereby provide a foundation of earth material upon which can be situated various type of hardware such as submerged barges or caissons, the tops of which ultimately penetrate the surface of the water body. In moms kiwi, to reduce slump, the idea of the land are supported with a retaining member such a a wall or caisson.
SUMMARY OF THE INVENTION
The present invention lo directed to a eddy and apparatus for constructing an artificial island by taking atr0noth~ned oil tanlcers, oil~bulk/ore or oil/ore tankers, transporting them to ohs diehard sites, either under their own power or by wowing, and partially sub-merging the hulls, with awry and waler ballast dredged from the Roe floor, The hulls can be used individually or in combination. The concept of Herb the flexibility of providing a movably drilling island, which can ha achieved in a relatively short lima by partially submerging the hull or hull, conducting the desired operation such as drilling an oil well, and then when completed, refloating the hull and transporting it to a new site. Alternatively, the partially submerged hull can be left in place to form a production or Tory platform The bow(s) of the substantially submerged hull B) would normally be pointed in the direction of the prevailing winds, WOW and ice action for the area.
The invention it directed to method of forming tubule drooling production or Atari facility in a relatively shallow hvdy of water which may be contested with ice or other objects comprising: con~tructlng a vessel which can float or be partially submerged by taking on liquid or solid ballast and of sufficient ma and strength to provide tabulate for oil well drilling, production or storage operations, and movement resistance against wave, ice and other objects equipping the vessel with a drilling rig and a drill stem and production cawing protector-rstainer located below the drilling rig, the protector-rQtainer extending downwardly from about the base of thy drilling rig or produc~lon facility to the bottom of the vessel;
importing the vessel to the water or ice bound area where thy drilling or production platform it to be lotted and submerging the vessel with liquid or solid ballast 80 that the buttock... of the vessel it founded on the bottom of the water body, or on a pad formed on the bottom of the water body, while the deck remains above water, the protector-re~ainer protecting drill stem and oil well production casing from interference by ice, wave or other object and restraining any fluid produced during drilling or operation of an oil well from string the surrounding body of water.
The method may include drilling an oil well into the floor of the water body while the partially submersed hull it founded on the bottom of the water body The hull may be refloated after being partially merged by removing ballast from the interior of the partially submerged hull.
I the oil jell experiences a blow-out during the drilling thereof, the curds oil it dlrec~ed into the $nterlor ox the partially submersed hull to prevent contamination of the water body. The oil direction can be automatic or by jump. A Rowley well may be drilled prom the ~ar~lally submerged hull while the oil well it experlenGin~ blow-out. Thy towered oil can by burnt off or hauled away.
In the method, protective barrier may be cons~ructad alongside By eye one wide of the partially submerged hull by drudging solid material from the water body floor and heaping it alongside thy partially submerged hull. Thy artificial island may be formed by two partially ~ubmarged ship hulls. The two partially submerged hull may be arrayed 3ide-by-side in parallel adjacent manner.
A protect barrier may be constructed alongside at least one wide of the partially submerged hull by dredging solid material from the water buddy floor and heaping it alongside the partially submerged lo hull which I arranged in V-pattern with another partially submerged hull. The protective barrier - aye -! g conY~ructed alongside at least one lye of the partially ~ubmarg~d hull may be formed by dredging solid and liquid material from the water body floor and phrasing the dreaded material, before duping the frozen material on the waler body floor alongside ha partially submersed hull.
A protective barrier may be ¢onstructad along-side at least one side of thy partially submerged hull by dredging solid and liquid material from the water lo body floor, duping the dredged material on the our-face of ice surrounding the partially submerged hull thereby sinking thy ice and the dredged material onto the water body floor. The dredged material is allowed to freeze prior to submerging, tarrier protection for the partially submerged hull may Allah be created by partially submerging it Lotte one ship hull 80 thee it projects radially from the main partially submerged hull. A plurality of ship hull on a radially deposed pattern may be placed around the c1rcumfer~nce of the main partially ~ubmergad hull. This is useful when the main hull us left in place a production or Tories platform.
The invention it directed to a movable oil well drilling and production structure capable of forming in a relatively Lowe body ox water which may be contested with ice and other objects a temporary or permanan~ water bDtto~ founder oil well drilling, production or storage facility comprising: a vessel capable of being at least partially aubmercJed to ret on the bottom ox the body of water or on a peal constructed on the bottom of the water body and of ~ufficiant mast and ~trenyth to provide stability for oil well drilling, production so storage operation and movement r~sl~tance again waves ice and other object; an oil wall drilling rip, production or Turks facility carried by the vowel and D protaçtor-retainer located under the drilling fig or production facility and extending downwardly from byway the bate of ha drilling rig or ~roductlon solute to the bottom of ho vessel Jo that when thy visual it founded on the bottom of the body of worry or on the pad, the protector-retainer prO~eCtB
drill to and oil well production cawing from interference by ice, wave or other ox jacket, and restrains any fluid produced during the drilling or operation of the oil well from entering the surrounding body of waxer.
I
- 6 ( a The vessel may include means for ejecting ballast from the interior of the hull to thereby refloat the partially submerged visual. The vessel may be self-propelling The vessel may have an oil well drilling rig mounted on the deck of eye hull. The vessel may also have a monopoly (an oil retaining cavity) built into part of the interior of` the hull below the drilling rig The hull of the vessel may be mounted on top of a second whip hull to provide a double Decker hull. The vessel may have two oil well drilling rigs moLInted on the deck of the hull and two monopoly built into the interior of the hull, one below each drilling rig.
Normally, the second monopoly would be at a reasonable distance prom the first monopoly In zones where the water body floor is mainly clay-like in character, refloating may become a problem due to suction created at the bottom of the vessel. In order to overcome this suction action, it might be desirable to install a number of pipes in the bottom of the hull or lnje~ting air or water at suitable pressure thereby relieving the suction force. In certain Sue-Sheehan, to withstand extreme lateral forces ho increasing the overall specific gravity of the submerged vessel, it may be necessary to use iron ore pellets as ballast instead of sand or the like no withstand ice pressures, and the like, the hull can be strengthened by using heavy steel cross-struts, inter-rib reinforcing. Alternatively or in accompaniment t the spaces between the frame members of the hull can be filled with concrete and steel rein-for cement. The rudder and propeller of the vessel can be protected within a housing formed in the vessel body so that the propeller and rudder can be used repeatedly as the vessel is submerged for a time, refloated and moved to a new site and then submerged again prior to drilling a the new site.
To prevent freezing of ballast waxer, such freezing bring capable of damaging the hull body, by expansionary ice force, insulation Jo reduce heat loss from the interior of the hull can be installed, or the ballast water can be heated by sore suitable economical means. The vessel can be equipped with its own dredge in, sand and water pumping equipment so that it is self-reliant.
DRAWINGS
In the drawings.
FIGURE 1 represents a perspective view of a tanker converted for use as an artificial island and drilling platform FIGURE 2 represents a perspective view of two hulls, one above the other, converted for use as an artificial island and drilling platform;
FIGURE 3 represents a side elevation view of the double Decker hull with a drilling rig erected in place over a monopoly in the hull;
FIGURE 4 rcprcscnts an end elevation view of the double Decker hull;
FIGURE 5 represents a side elevation view of the double Decker hull supporting two drilling rigs, one rig for drilling the primary oil well and a second rig for drilling a second oil will or a relief well;
FIGURE 6 represent a side elevation view of the two rig double Decker hull combination depicted in FIGURE 5 above, illustrating the manner in which a relief hole it drilled to intersect with the main drilling hole, FIGURE 7 represents a plan view of a converted hull equipped with two Minneapolis for dual fly drilling capability FIGURE 8 represents an end elevation view of the hull depicted in FIGURE 7 above resting on the sea floor;
FIGURE 9 represents a plan vie of two converted hulls placed in parallel aligned position;
FIGURE 10 represent an end elevation view of the twin hull depicted in FIGURE 9 above;
FIGURE 11 represent a plan view of a hull converted according to the invention, together with a dual-direction conveyor belt arrangement which can be utilized for manufacturing protective ice-earth debris and dumping it alongside the hull to provide a submerged protective barrier for the hull;
FIGURE 12 reappearance a front elevation view of the ship hull depicted in FIGURE 11 above, illustrating the manner in which debris it placed on either side of the hull to provide a projection barrier for the hull;
FIGURE 13 represents an end elevation view of a pair of converted double Decker hulls placed in parallel adjacent alignment with one another;
IRE 14 represent a plan elevation view of a hull equipped with bottom debris pumping and spraying equipment for use in spraying sand and soil onto the ice perimeter surrounding the hull;
FIGURE 15 represents a plan elevation view of a converted hull which may be detached in thy mid-region to provide an artificial drilling island comprising the two detached portions of the hull arranged in parallel adjacerlt positions FIGURE 16 represents a plan elevation view of two adjacent aligned converted hulls, surrounded by reinforcing barrier debris and a plurality of radially disposed tanker Howe around the perimeter of the barrier;
FIGURE 17 represents a plan elevation view of two converted hulls arranged to provide a wedge arrange-mint for withstanding ice and wave forces;
FIGURE 18 represents an end elevation Al view ox the two Howe described in FIGLlRE 17 above;
2Q FIGURE 19 reprint a plan view of the manner in which four converted hull can be utilized to provide a protective whip harbor;
FIGURE 20 represents a plan view of the manner in which two converted hulls can be arranged in end to end relationship to provide an aircraft landing strip FIGURE 21 represents a side elevation view of a twin hull design pitted with a new bow section FIGURE 22 represents a plan elevation view of a twin hull design fitted with a new boy section;
FIGURE 23 reprint a side elevation view of a twin hull design fitted with a new bow section and a gunwales height extension;
FIGURE 24 represents a plan elevation view of a twin hull design fitted with a new bow section and a gunwales height extension;
FIGURE 25 represents a side elevation view of a double Decker twin hull combination design, with the lower twin hulls fitted with a new bow section;
FIGURE 26 represents a plan elevation view of a double Decker twin hull combination design, with the lower twin hulls fitted with a new bow section.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGURE 1, a ship hull I accord-15 in to one aspect of the invention, is equipped with and carries a drill rig 4. The hull is shown located in a large body of ice 6. While not shown, the bottom of the I
- AYE -Sue hull 2 rests on the bottom of the body of water support-in the ice 6. The drill rig 4 is positioner towards the stern of the hull 2 ahead of the wheel house 8. The bow of the hull carries a heliport 12 which serves as a landing pad for a helicopter 10. The helicopter 10 serves to provide 8uppl it for operation of the hull-drill rig assembly. The hull 2 is suitable for opera-lion in water of about 20 meres depth. This leaves about 5 Quoter of freeboard.
FIGURE illustrates the manner in which, according to another aspect of the invention, one hull 14 is positioned above and secured to a second hull 16 in double Decker manner. This double Decker hull combination enables the hull-rig combination to operate in deeper waters than the single hull version, for example, waters of about 45 metros depth.
The double Decker hull arrangement as shown in FIGURE 2 can be manufactured in a number of ways. One possible way it to clean away the normal cock e~luil~ment on a hull, sink the hull with suitable ballast, move second floating hull into position over the submerged hull, and then secure the two hulls together by suitable bracing such as steel beams, welding and the like.
Wedges must be inserted in the tapered spaces that normally exit between the deck of the underlying hull and the bottom of the superimpose hull to offset the lateral camber ousto~arily built Unto the fleck of the underlying hull.
Normally, in Arctic waters. such as the Beau fort Sea, either the single hull or douhle-decker hull design, when founded upon the floor of the water-body, should be oriented with its bow facing to the northwest into the direction of prevailing winds, waves and ice migration prevalent in those areas. Even so, in some locations, a wave deflector may be required along one side to increase freeboard and limit the volume of water token on deck from maximum broadside waves.
FIGURE 3 represents a side elevation view of the double Decker hull design depicted in FIGURE I The upper hull 14 is secured Jo the lower hull by welding cables, steel reinforcement, and the like. As can be teen in FIGURE 3, the drill rig 4 is positioned above a monopoly 18 which extends vertically prom the fleck of the upper hull 14 through the two hulls, to the bottom of the lower hull 160 The monopoly 18 is an enclosed cavity open to the atmosphere with overflow drains into the hull or hull compartments. As can be seen in FIGURE 3, the drill rig 4, by being positioned above the monopoly 18, can raise and lower drill stem 20 through the monopoly 18 into the scabbed below the bottom of hull 16 for drilling in the manner of a conventional oil well.
A very significant advantage of the moon-pool 18 design is that if there it a blow-out of the well being drilled, the crude oil that is blown out can be initially contained within the confines of the moon-pool 18 and then directed into the hull or compartments thereby completely preventing pollution in the delicate environment of the Arctic. If the blow-out is extensive and long lasting, the escaping crude can be directed automatically or pumped into the sizable compartment in the upper hull 14 and the lower hull 16. The capacity of these two hulls, even if partially taken up with ballast, it significant and can in most cases contain four to six months "wild" production from the well.
FIGURE 4 shows an end elevation view of the double Decker hull design including the upper hull 14, the lower hull 16 and the monopoly 180 FIGURE 4 also illustrates the wedges 22 which are welded or secured in place between the upper and lower hulls in order to off-set the camber of the deck of the lower hull 16 and provide a stable secure fit between the upper hull 1 and the lower hull 16.
As FIGURE 5 demonstrates, the double Decker lo hull design can be fitted with two drilling rigs 4 and I In such a case, the ship is also fitted With two Minneapolis 18 and 26 respectively. The second rig 24 can be used for drilling a relief hole to intersect with the main hole being drilled by rig 4 if for sore reason, such as a blow-out or a collapsillg formation, it icky necessary to interconnect with the first hole. The auxiliary rig 24, rather than acting as a relief mews-urea can be used to drill a second hole at the same time that the first hole is being drilled The direction of the two hole can be diverged by means of directional drill bit. This tandem arrangement can be important in areas where the drilling season is short.
FIGURE 6 illustrates in side elevation view the manner in which a relief hole 28 can intersect with Jo main hole 30 utilizing the dual rig arrangement, fig 4 and rig 24, discussed above.
FIGURE 7 illustrates in plan elevation view a typical single hull 32 with two Minneapolis 34 and 36.
FIGURE 8 illustrates in end elevation Al view the manner in which a berm 38 may be built up on one side of hull 32. Alternatively, the berm 3Q allows reduced ballasted weight on relatively weak soils err the depth of such toils make it impracticable to remove them.
FIGURE 9 depicts in plan elevation view a twin-hull alignment that can be utilized where the sea bed soil is weak or where the predicted ice or wave forces may be greater than can reasonably be endured by a single hull. the parallel arrangement of the win ship 40 and 42 immediately doubles the lateral no instance for the same effective ballasted weight, Alternatively, this win hull arrangement can allow a reduced ballasted weight on relatively weak soil of low stability where the extensive depth of such soils makes it impractical to remove them. FIGURE 10 demonstrates in end elevation view the twin hull concept 40 and 42, and thy manner in which the two hulls are founded on the sea-bed.
FIGURE 11 illustrator a system which can be u~2d for manufacturing solid debris for distributing along the yea floor to build-up a protective barrier along the sides ox the vessel 46. The vessel shown has two Minneapolis 48 and 50. The system consists of a suction line 52 which has one end resting on the sea floor. The line 52, by means of suction exerted by Bud and sand pump 54, or the like, draws up clay, sand, sea water, and other solid material from the sea bottom and deposits it on a tony moving conveyor 56 which extends substantially the length of the vessel 46. The solid water mixture deposited on the conveyor 56, when ambient temperatures are well below freezing such as in the Arctic during the winter, freezes into a solid mass as it is conveyed along the conveyor 56. At the end of 10 the conveyor 56, away from pump 54, the solid material is deposited onto an adjacent conveyor 58 which runs in a direction parallel with and opposite to conveyor 56~
Conveyor 56 is normally located at the edge of the hull of the vessel 46. By means of a mechanical arm or manual power, or the like, the frozen solid debris traveling along conveyor 58 can be broken into lumps which are then pushed over the side of the vessel so as to wink to the bottom of the water body. In this way, a barrier of idea material, which should remain in frozen condition for a significant length of time, can be built up alongside the submerged hull of the vessel 46. Thus provides valuable protection for the hull 46 against lateral pressures exerted by waves and ice. The system described can be utilized for depositing a similar barrier along the opposite side of the hull 46. To slow down thawing of the frozen debris once it has been deposited in the sea waxer, cedar bark or other cheap, available coarse material with insulating qualities can be incorporated in the debris while it is hying frozen.
30 Such material can be carried into the vessel's hold initially or be brought to the site in a supply ship or the like.
FIGURE 12 depicts in an end elevation view the method whereby debris 60 and 62 can be built up along each ire of the vessel 46.
FIGURE 13 represents in end elevation view a combination of vessel hulls which can be achieved by combining the twin-hull concept of FIGURE 9 with the double Decker hull concept of FIGURE 12~ This combination can be utilized in areas where the water depth is in the range 20 to 45 metros and excessive ice and wave action pressures are encountered, thereby requiring extra stability.
FIGURE 14 in plan elevation view illustrates a lo system whereby suction pumps in combination with suction lines which draw solid and liquid material from the sea-bed can be utilized for pumping and spraying sand, silt and other bottom material onto the ice surface surround-in the vessel 68. The Betty material is allowed to Roy to by contlguou~ with the ice. Eventually, with build-up, the heavy weight of the solid material pumped onto the ice around the perimeter of the vessel 68 Jill submerge the ice whereupon everything will sink to the yea bottom In this way, with repeated build-up of ice, 25 and depositing of sand and debris onto the surface of such fillip ice, an effective ice-solid barrier wall can be built up around the perimeter of the vessel 63.
FIGURE lo shows in plan elevation manner a split hull design which can be detached at its mid-region and the two separate hulls placed alongside one another in parallel manner to provide a twin hull con-figuration as illustrated above in FIGURE 9.
FIGURE 16 illustrates in plan elevation view a system that can be used for reinforcing an artificial island created by a twin hull combination, and a harrier reef built up around the periphery of the twin hulls, to withstand for a long period of time extremely severe ice and wave forces emanating from any direction. A number of hull, ten are shown, ballasted so that they sink to and rest on the sea floor, are arranged in radial pattern around the circumference of the twin hull-surrounding barrier island combination. The ballasted hulls that are arranged radially should have their noses the ends of the hull remote from the twin hull-barrier combination) cut down, sloped downwardly, or submerged below the ice level on the water/ so that any ice what may contact the nose of those hulls will tend to ride up on the hull, and translate the forces downwardly.
This is preferable Jo having the ice Inset the noses I head-on and thereby impart the forces through the hulls directly onto the peripheral barrier protecting the twin hulls. Preferably, the radially disposed partially sub-merged hulls are initially ballasted with large objects such as rocks and the like and transported partially I submerged to the site. Rocks are preferred so that if any holes are punched in the Howe by ice, the ballast will not wow out through the hole onto the sea floor, thereby losing e~fec~ivenea3 as ballast. ennui no longer of use, the holes can be sealed, the hull refloated and transported.
FIGURE 17 illustrates a variation of the twin hull concept illustrated in FIGURE 9 whereby two hulls 70 and 72 are arranged in a Y pattern (inverted in FIGURE 17~. The point of the V faces the direction of prevailing wind, ice and waves The space between the arts of the V are filled with sand, solid debris and the like in order to prevent the two Veranda hulls from being forced to move under the pressure from ice and waves. FIGURE 18 illustrates in end elevation view the manner in which the V-arranged hulls are founded on the sea floor.
FIGURE 19 illustrates in plan elevation view an arrangement of three hulls, together with a shorter ship hull, to provide a protected harbor area for a supply ship or a production transportation ship for a well which has been drilled in hostile waters such as the Arctic Ocean, Three of the vessels 74, I and 78, are arranged so that their respective boys or sterns intersect to provide a generally "U-shapedi' configure-lion. The pen end of the "U" is partially closed by means of a vessel of shorter length 80. The supply ship 82 can enter and leave the protected area formed by the linked vessel arrangement through the opening exist-in between vessels 78 and 80.
FIGURE 20 illustrates the manner in which two vessels 84 and a may be arranged in end to end align-mint BY as to form a long surface which can be converted into a runway for aircraft. Normally, two vessels arranged in this manner should be of sufficient length to provide a landing and takeoff area for transport aircraft such as Hercules or Caribou aircraft.
FIGURES 21 and 22 illustrate an embodiment of the invention wherein two hulls 90 and 92 ore arranged side-by~side, in parallel alignment, in twin-hull pattern, the combination being it'd with a new bow section 94. A rig 96 is mounted at the fore of hull 92 and optionally a relief rig 98 can be positioned at the aft section of hull 900 FIGURES 23 and 24 illustrate a further embodiment of the invention wherein two hulls 100 and 102 are arranged in twin-hull pattern, the combination bring fitted with a gunwale height extension 104 and a new bow suction 1060 A rig 108 is mounted at the fore of hull 102 and optionally a relies rig 110 can be positioned at the aft section of hull 100~
Flyers 25 and 26 illustrate a further embodiment of the invention wherein two hulls (one hull I identified a 112 while thy skin cannot by Zen in either FIGURES 25 and 26) are arranged in twin-hull pattern while a second pair of hulls 114 and 116 are superimposed in double Decker twin-hull pattern upon the underlying twin hulls 112 and the unseen hull. A new bow section 118 it fitted at the front ox the lower twin hulls. A new tern section 120 is fitted at the rear ox the upper twin hull 114 and 116. Drilling rig 1~2 and optional relief rig 124 are mounted on the upper twin decks. This configuration provides double height and double lateral stability.
- 19~
The predominant force is from ice and the maximum lateral force on the vessel founded within the land fast ice, including wind and current forces, may amount to as much as 118,000 tones. The effective submerged weight to resist lateral movement will depend upon sea-bed conditions buy it likely to average about 236,000 Tony for the single ship hull concept.
While a bottom sea depth of about 20 metros is feasible for the jingle converted hull configuration, if drilling it to be conducted in waters deeper than about 20 metros, then in place of the double-deck~r hull design, if required, a sand-base or rock-base island can be built up to within a depth of 20 metros below the high waxer mark end the jingle hull design founded on what island.
The single or double Decker hull concept pro-vises a relatively inexpensive movable drilling island which, in the short time available in Arctic regions, can be advantageously moved by towing or self-propulsion to a prospective drilling site, sunk so that it rests on the sea floor by use of permanent and temporary ballast, and then Atari a well is drilled (typically 90-180 days), be refloated and moved to a new drilling site.
In this way, the jingle or double Decker hull concept provides the possibility of drilling two oil well holes per year in different locations, one typically in the winter, the second typically in the summer. In an average year, with some ice breaker assistance, it - 19~ --should be possible to refloat and transfer the rig-vessel to a now location in June or July of each year.
During period when the seas are generally calm, the sinking of the hull to the sea bed will be a relatively easy operation. When water are rough and lateral forces from ice pressure prevail, sinking the hull to revs on thy sea bottom will require more bottom preparation and care.
The depth to which a vessel may be sunk as a grounded drilling island will depend on the freeboard required in relation to the extreme peak wave heights on the bow and sides of the hull. Considerable water and spray may be accepted over the deck surface and drained way through suppers during extreme wave action.
Alternatively, wave and spray deflectors can be built along the sides of the hull to increase the effect of freeboard. Ideally, temporary ballast used to submerge the hull should be in the form of sea water so that it can be easily pumped out prior to moving at a new site.
However, send and other heavier material will sometimes be used for temporary ballast in order to provide increased stability to the hull when founded on the sea bottom. To refloat the hull, the sea water used as ballast may by pumped out. If sand ballast is used, it may he necessary to remove the sand by solve suitable jeans before sufficient buoyancy of the hull can be achieved to refloat the visual A complicating factor in areas where the sea bottom it mostly clay is the possibility of strong suction forces being exerted on the bottom of the hull. To overcome this, it may be desirable to install a number of small pipes to the bottom of the hull (preferably outside the hull) for injecting air or water at suitable pressure into the interface between the clay Betty and the keel ox the hull. Alternatively, a sand bed can be put down prior to founding the hull on the bottom to prevent suction problems.
To withstand the substantial external ice and wave force, the hull must typically be strengthened.
One method may involve adding additional vertical steel members between the main frames to withstand the ice forces over the range of height in which they would act.
A second alternative may be to fill between the main frames with concrete and additional steel reinforcement a required.
To protect the propeller and rudder of the vessel from ice damage, and She like, the propeller area of the vessel should be protected. This may include housing the propeller in a suitable housing that is sufficiently strong to wlth~tand the substantial ice pressures that might be exerted.
To prevent damage to the interior of the hull that might occur due to freezing of ballast water and the like within the hull at portions of the hull that remain above the water level, insulation to reduce heat 105g or ballast heating water means may be used.
Waves acting on the ship will cause scour erosion to the water body floor supporting the vessel and suitable scour protection should be used. However, in Arctic waters, this scour time will usually be fairly I
short, that is, from the time of founding of the vessel upon the sea bottom to freeze up. Thus, if the vessel is founded on cohesive material or if limited scour can be tolerated, scour protection may not be required.
S Sand berms or submerged frozen blocks can be provided alongside thy hull to provide passive resistance or to increase the path of foundation failure.
The exact requirements for foundation treat-mint and scour protection will Append on the local sea-bed conditions and depth of urea specific to each site. Geotechnlcal investigations of the proposed site should be carried out in advance in order to prepare a proper design for foundation treatment and make plans or all necessary materials and equipment.
The V arrangement of two ships us illustrate in FIGURES 17 and 18 has two possible advantages:
(a) It allows a wedge of sand to be placed in a protected area between the two vessels for increased lateral ruttiness; and (b) It allow the possibility of having the main and emergency drilling wells placed on separate vessels Father than having two Minneapolis on one vessel) and thereby provide an alternative safety procedure in the event of blow-out or fire Temperature, Precipitation and Visibility Typical weather summaries c3enerated from station in the euphoria Sea area provide the following general data:
(1) Extreme low temperatures occur from December to March inclusive and range from -42~C to -50C. Mean daily temperatures during the same months range from -25C to -30DC~
( 2 ) Mean wind speeds do not vary greatly throughout the year but tend to be least in February and greatest in September and October.
(3) Fog is worst during June to August with visibility less than 10 km. occurring nearly 20~ of the lime. Blowing snow occurs about 12~ of the time from October to April.
Ice Conditions in the effort Sea Ice in the Beau fort Sea consists of two main features the polar pack which is in constant rotational counterclockwise motion due to the rotation of the earth, and the land fast ice which forms in the autumn and breaks up in the early summer.
During a typical summer, the permanent polar pack resides between 2~0 and 400 km. offshore. In the fall, driven by offshore winds, the polar pack advances to about the edge so the 100 mete Squibb contour existing to the north of aniline Canada. ~irnulta-nuzzle, in early October, a band of new lank fast ice begins to form along the shore. The final width of this lank fast ice zone is very much dependent on the sequence of events at freeze-up. The ultimate extent of the land fat ice is related Jo water depth, with the 20 moire sea-bed contour normally defining the off-shore fast ice limits, which are reached in a series of growth stages by February or March.
Because the land fast ice is stationary while the permanent polar pack is in continuous motion, a winter transition zone exists between the two lee zones.
During the fall, the pressure of the polar pack against the thin first year land fast ice causes considerable deformation and the southern boundary of the transition zone consequently becomes marked by an area of heavy ridge activity The most active area is generally a band between 5 and 10 km. wide known as the shear zone To the north, the transition zone continues out to about the 100 moire water depth, but this is extremely variable, and there is no distinct boundary between this zone and the polar pack. Generally, there is a gradual increase in multi-year ice concentration moving north, but this is usually difficult to detect in mid-winter overflight.
As early as March, the polar pack can start to recede, creating a lead between it and the land fast ice. Depending on surface weather, the width of the lead and ice concentrations can vary on a daily basis.
Initially the land fast ice remains intact, but as break-up progresses , floes pull away from the outer edge while the Mackenzie River outflow and other rivers erode the inner side. In this manner, the land fast ice is generally breached by late June or early July on the west side of the MacKenzie River Delta and at the Horton I Rover in Franklin Bay. The remaining fast ice breaks out shortly thereafter.
Summer ice concentrations between the 20 and 100 moire water depths can be extremely variable. In good years, virtually open water can exist throughout from early July to late October. In adverse summers, there is no significant clearing until late August, and freeze up begins in early October.
As can be appreciated, these ice conditions can generate varied and tremendous hazards and pressures for oil exploration actlvl~y in the Beau fort Sea. The various aspects of the invention disclosed above should enable mankind to deal with these adverse conditions more effusively and lest expensively.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alteration and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
I
Ice Conditions in the effort Sea Ice in the Beau fort Sea consists of two main features the polar pack which is in constant rotational counterclockwise motion due to the rotation of the earth, and the land fast ice which forms in the autumn and breaks up in the early summer.
During a typical summer, the permanent polar pack resides between 2~0 and 400 km. offshore. In the fall, driven by offshore winds, the polar pack advances to about the edge so the 100 mete Squibb contour existing to the north of aniline Canada. ~irnulta-nuzzle, in early October, a band of new lank fast ice begins to form along the shore. The final width of this lank fast ice zone is very much dependent on the sequence of events at freeze-up. The ultimate extent of the land fat ice is related Jo water depth, with the 20 moire sea-bed contour normally defining the off-shore fast ice limits, which are reached in a series of growth stages by February or March.
Because the land fast ice is stationary while the permanent polar pack is in continuous motion, a winter transition zone exists between the two lee zones.
During the fall, the pressure of the polar pack against the thin first year land fast ice causes considerable deformation and the southern boundary of the transition zone consequently becomes marked by an area of heavy ridge activity The most active area is generally a band between 5 and 10 km. wide known as the shear zone To the north, the transition zone continues out to about the 100 moire water depth, but this is extremely variable, and there is no distinct boundary between this zone and the polar pack. Generally, there is a gradual increase in multi-year ice concentration moving north, but this is usually difficult to detect in mid-winter overflight.
As early as March, the polar pack can start to recede, creating a lead between it and the land fast ice. Depending on surface weather, the width of the lead and ice concentrations can vary on a daily basis.
Initially the land fast ice remains intact, but as break-up progresses , floes pull away from the outer edge while the Mackenzie River outflow and other rivers erode the inner side. In this manner, the land fast ice is generally breached by late June or early July on the west side of the MacKenzie River Delta and at the Horton I Rover in Franklin Bay. The remaining fast ice breaks out shortly thereafter.
Summer ice concentrations between the 20 and 100 moire water depths can be extremely variable. In good years, virtually open water can exist throughout from early July to late October. In adverse summers, there is no significant clearing until late August, and freeze up begins in early October.
As can be appreciated, these ice conditions can generate varied and tremendous hazards and pressures for oil exploration actlvl~y in the Beau fort Sea. The various aspects of the invention disclosed above should enable mankind to deal with these adverse conditions more effusively and lest expensively.
As will be apparent to those skilled in the art in the light of the foregoing disclosure, many alteration and modifications are possible in the practice of this invention without departing from the spirit or scope thereof. Accordingly, the scope of the invention is to be construed in accordance with the substance defined by the following claims.
I
Claims (28)
1. An oil well drilling unit for forming in a rela-tively shallow body of water which may be congested with ice and other materials an oil well drilling facility positioned on the bottom of the body of water, said unit comprising:
(a) a conventionally designed tanker normally capable of transporting oil, bulk material, ore material or a combination of the foregoing materials, said tanker being capable of having its hull at least partially submerged to rest on the bottom of the body of water and being of a strength sufficient to provide stability for an oil well operation and resistance against damage due to ice and other materials that may be present in the body of water, said tanker having an enclosed cavity means extending vertically downwardly completely through the tanker;
(b) means on the tanker for taking on moveable ballast for sinking at least a portion of the hull of the tanker onto the bottom of the body of water; and, (c) an oil well drilling rig mounted on the deck of the tanker above said cavity means.
(a) a conventionally designed tanker normally capable of transporting oil, bulk material, ore material or a combination of the foregoing materials, said tanker being capable of having its hull at least partially submerged to rest on the bottom of the body of water and being of a strength sufficient to provide stability for an oil well operation and resistance against damage due to ice and other materials that may be present in the body of water, said tanker having an enclosed cavity means extending vertically downwardly completely through the tanker;
(b) means on the tanker for taking on moveable ballast for sinking at least a portion of the hull of the tanker onto the bottom of the body of water; and, (c) an oil well drilling rig mounted on the deck of the tanker above said cavity means.
2. An oil well drilling unit as called for in Claim 1 wherein means are provided mounted on the tanker for propelling the tanker to the place on the body of water where it is to be submerged.
3. An oil well drilling unit as called for in Claim 1 wherein means are provided on the tanker for ejecting moveable ballast from the tanker in order to refloat the tanker.
4. An oil well drilling unit as called for in Claim 1 wherein a compartment is provided in the tanker in fluid communication with the cavity means whereby fluid materials escaping from the drill hole into the cavity means may be directed from the cavity means into the com-partment.
5. An oil well drilling unit as called for in Claim 1 wherein a compartment is provided in the tanker in fluid communication with the cavity means and pumping means are provided for pumping fluid from the cavity means into the compartment, whereby fluid materials escaping from the drill hole into the cavity means may be pumped into the compartment.
6. An oil well drilling unit in accordance with Claim 1 wherein means are provided on said tanker to collect solid material from the bottom of the body of water and to distribute such collected material along at least one side of the hull of the tanker to form a barrier of solid material along at least one longitudinally extending side of the hull of the tanker when same is in a partially submerged state.
7. An oil well drilling unit as called for in Claim 1 wherein said oil well drilling unit is positioned on the bottom of a body of water congested with ice in a substantially locked-in state, and barrier material is positioned along at least one side of the tanker hull in a fore and aft direction to resist the pressure of the ice.
8. An oil well drilling unit in accordance with Claim 6 wherein said means for collecting and distributing material from the bottom of the body of water comprises a suction line for sucking up through one end the material from the bottom of the body of water, first conveyor means mounted on the deck of the tanker and extending longitudi-nally along substantially the entire length of the tanker in substantially parallel relationship with the deck of the tanker, said first conveyor means operatively associated at one end with the discharge end of the suction line to receive material sucked up from the bottom of the body of water, means to move said conveyor in a direction away from the discharge end of the suction line, a second conveyor means mounted on the deck of the tanker for substantially the entire length thereof in parallel relationship to and outboard of the first conveyor means, and means to move said second conveyor means in a direction opposite to the direction of said first conveyor means, whereby material may be sucked up from the bottom of the body of water and discharged on to the moving first conveyor means, thereafter transferred at the opposite end of the first conveyor means to the moving second conveyor means with said material being in a substantially solid state, and thereafter may be broken up and discharged over the side of the tanker and fall to the bottom of the body of water and form a barrier along the longitudinally extending side wall of the sub-merged hull portion of the tanker.
9. An oil well drilling unit in accordance with Claim 1 wherein means are provided on the tanker to collect liquid and solid material from the bottom of the body of water and to spray the material onto the body of water along at least one side of the hull of the tanker when same is in a partially submerged state.
10. An oil well drilling unit in accordance with Claim 1 wherein the hull of the tanker, in cross-section has each longitudinal side inclined upwardly and inwardly.
11. An oil well drilling unit in accordance with Claim 1 wherein the tanker is positioned on a like tanker in vertical relationship therewith and secured thereto with the enclosed cavity means of the two tankers in vertical alignment with each other.
12. An oil well drilling unit in accordance with Claim 1 wherein a second tanker is operatively associated in side-by-side relationship with said tanker.
13. An oil well drilling unit in accordance with Claim 12 wherein said second tanker is provided with an oil well drilling rig above its enclosed cavity means.
14. An oil well drilling unit in accordance with Claim 1 wherein said tanker has a second enclosed cavity means formed therein in spaced relationship to the other cavity means, said second cavity means being of substantially identical construction to the other cavity means.
15. An oil well drilling unit wherein two vertically arranged tankers in accordance with Claim 11 are operatively associated in side-by-side relationship.
16. A method wherein a bed of sand is prepared on the bottom of a relatively shallow body of water, a tanker as called for by Claim 1 is floated in said body of water to a position above said bed of sand, the tanker is at least partially submerged by taking on moveable ballast so that it rests on the bottom of the body of water on said sand bed, and the unit is then used in drilling operations.
17. A method wherein a bed of sand is prepared on the bottom of a relatively shallow body of water, a tanker as called for by Claim 3 is floated in said body of water to a position above said bed of sand, the tanker is at least partially submerged by taking on moveable ballast so that it rests on the bottom of the body of water on said bed, the unit is used in drilling operations, and the tanker is refloated by ejecting moveable ballast from the tanker.
18. A method wherein a tanker as called for by Claim 1 is at least partially submerged in a relatively shallow body of water by taking on moveable ballast so that it is founded on the bottom of the body of water, a pro-tective barrier is constructed along the side of the hull of the tanker by dredging liquid and solid material from the water body floor and heaping it alongside the hull using dredging mechanism on said tanker, and using the unit in drilling operations.
19. A method according to Claim 18 wherein the liquid and solid material is allowed to freeze after it is dredged from the water body floor, and is broken up into frozen blocks and deposited alongside the hull.
20. A method in accordance with Claim 19 wherein the solid and liquid material is mixed with a coarse insulating material before it is allowed to freeze.
21. A method in accordance with Claim 20 wherein the coarse insulating material is cedar bark.
22. A method wherein a tanker as called for by Claim 1 is at least partially submerged in a relatively shallow body of water by taking on moveable ballast so that it is founded on the bottom of the body of water, a protective barrier is constructed along the side of the hull of the tanker by spraying liquid and solid material from the bottom of the body of water onto the surface of ice, using dredging mechanism on said tanker, along at least one side of the hull of the tanker until ice and the sprayed liquid and solid material sinks to the bottom to form a protective barrier along at least one side of the hull of the tanker, and using the unit in drilling operations.
23. A method in accordance with Claim 22 wherein the protective barrier is formed by spraying liquid and solid material from the bottom of the body of water onto the surface of ice until ice and the sprayed liquid and solid material sink to the bottom, allowing ice to re-form on the surface of the water and again spraying liquid and solid material onto the ice until ice and the sprayed liquid and solid material sink to become a part of the protective barrier.
24. A method wherein at least two tankers as set forth in Claim 1 are at least partially submerged in a relatively shallow body of water in a V pattern so that each tanker is founded on the bottom of the body of water, a protective barrier is constructed alongside the tankers in the V shaped area between the tankers by dredging solid material from the bottom of the water body and heaping it in said area using dredging mechanism on at least one of said tankers, placing an oil well drilling rig on the deck of at least one of said tankers above the enclosed cavity means, and utilizing the vessels as an oil well drilling unit.
25. A method wherein a drilling unit as called for by Claim 1 is floated in a relatively shallow body of water and is at least partially submerged by taking on moveable ballast so that it is founded on the bottom of the body of water, a plurality of tankers as defined in Claim 1 are arranged to form a protective barrier in a radial pattern about said drilling unit said tankers being at least partially submerged by taking on moveable ballast so that they are founded on the bottom of the body of water, and using the said unit in drilling operations.
26. A method wherein a plurality of tankers as defined in Claim 1 are at least partially submerged so that each tanker is founded on the bottom of the water body and the tankers are arranged in side-by-side substan-tially parallel and abutting relationship and attached together an oil well drilling rig is mounted on the deck of at least one of the tankers above the cavity means, and the structure is utilized as a unitary drilling island.
27. A method wherein a plurality of tankers as defined in Claim 1 are arranged one on top of the other with their cavity means in vertical alignment, the tankers being secured together and with the lowermost tanker entirely submerged with its bottom founded on the bottom of the water body and the uppermost tanker is partially submerged, an oil well drilling rig is mounted on the deck of the uppermost tanker above the aligned cavity means, and the structure is utilized as a unitary drilling island.
28. A method wherein at least four tankers as defined in Claim 1 are arranged in upper and lower pairs of tankers, the tankers of each pair being arranged in side-by-side substantially parallel relationship and attached together, the upper and lower pairs of tankers being interconnected and with their cavity means in vertical alignment, the lower pair of tankers being entirely submerged with the hulls of the tankers founded on the bottom of the water body and the upper pair of tankers is partially submerged, an oil well drilling rig is mounted on the deck of at least one of the upper pair of tankers above the aligned cavity means, and the structure is utilized as a unitary drilling island.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000439148A CA1185800A (en) | 1983-10-17 | 1983-10-17 | Method and apparatus for constructing an artificial island |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000439148A CA1185800A (en) | 1983-10-17 | 1983-10-17 | Method and apparatus for constructing an artificial island |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000404924A Division CA1156477A (en) | 1982-06-11 | 1982-06-11 | Method and apparatus for constructing an artificial island |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1185800A true CA1185800A (en) | 1985-04-23 |
Family
ID=4126299
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000439148A Expired CA1185800A (en) | 1983-10-17 | 1983-10-17 | Method and apparatus for constructing an artificial island |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1185800A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005073471A1 (en) * | 2004-01-28 | 2005-08-11 | Max Streicher Gmbh & Co. Kg Aa | Foundation construction for a deep-drilling platform |
-
1983
- 1983-10-17 CA CA000439148A patent/CA1185800A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2005073471A1 (en) * | 2004-01-28 | 2005-08-11 | Max Streicher Gmbh & Co. Kg Aa | Foundation construction for a deep-drilling platform |
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