US4187039A — Method and apparatus for constructing and maintai…

Claim 1

Independent Claim 165 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and means for passively extracting heat from the water within said enclosure and soil below said caissons wherein said passive heat extracting means is located within said enclosure extending substantially to the soil below said enclosure and said passive heat extracting means is located within said caissons extending from the top of said caissons through the bottom of said caissons and into the soil below said caissons such that said passive heat extracting means accelerates the freezing of the water within the enclosure and the soil below said caissons in a unitary manner forming a mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island.

Claim 2

Independent Claim 165 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and means for passively extracting heat from the water within said enclosure and soil below said caissons wherein said passive heat extracting means is located within said enclosure extending substantially to the soil below said enclosure and said passive heat extracting means is located within said caissons extending from the top of said caissons through the bottom of said caissons and into the soil below said caissons such that said passive heat extracting means accelerates the freezing of the water within the enclosure and the soil below said caissons in a unitary manner forming a mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island.

Claim 3

Dependent Claim 21 words

The apparatus according to claim 1 wherein said apparatus further includes means for supporting said heat extracting means within said enclosure.

Claim 4

Dependent Claim 53 words

The apparatus according to claim 2 wherein said heat extracting means comprises a plurality of enclosed elongated members having a refrigerant material enclosed therein, said heat extracting means is supported over said enclosure by said support means such that one end of each elongated member contacts the bottom of said body of water.

Claim 5

Dependent Claim 37 words

The apparatus according to claim 3 wherein said support means comprises a plurality of cables attached to said caisson and having one end of each of said elongated member attached to one of said plurality of cables.

Claim 6

Dependent Claim 41 words

The apparatus according to claim 1 wherein said apparatus further includes means for refrigerating the top surface of the ice within said enclosure to prevent surface melting during the warmer months and to maintain the ice island in a frozen state.

Claim 7

Independent Claim 50 words

The apparatus according to claims 2 or 5 wherein said apparatus further includes an open tubular member supported on the bottom of the body of water and passing through said enclosure to provide an open chamber from the surface of the water to the bottom of the body of water.

Claim 8

Dependent Claim 41 words

The apparatus according to claim 6 wherein said apparatus further includes means for maintaining the ice outside the peripheral edge of said caissons in a weakened state to reduce the load imposed on the ice island by the surrounding ice formation.

Claim 9

Dependent Claim 31 words

The apparatus according to claim 7 wherein said means for maintaining the ice in a weakened state comprises an electrical resistance heating cable circumscribing the outer peripheral edge of said caissons.

Claim 10

Dependent Claim 60 words

The apparatus according to claim 1 wherein said passive heat extracting means within said enclosure penetrates the bottom of the body of water such that the penetration of said heat extracting means increases radially with respect to the center of said enclosure forming a wedge-shaped mass attached to said frozen soil ring further improving the lateral stability of said island.

Claim 11

Independent Claim 190 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons arranged in a ring configuration defining an enclosure to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a means for passively extracting heat from the body of water within said enclosure and from the soil beneath and below said caissons and said body of water within said enclosure; (c) passively removing heat from the body of water within said enclosure by said passive heat extracting means to advance the freezing of the body of water within said enclosure forming said ice structure; and (d) further passively removing heat from the soil below and beneath said caissons and said enclosure to advance the freezing of said soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 12

Independent Claim 190 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons arranged in a ring configuration defining an enclosure to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a means for passively extracting heat from the body of water within said enclosure and from the soil beneath and below said caissons and said body of water within said enclosure; (c) passively removing heat from the body of water within said enclosure by said passive heat extracting means to advance the freezing of the body of water within said enclosure forming said ice structure; and (d) further passively removing heat from the soil below and beneath said caissons and said enclosure to advance the freezing of said soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 13

Dependent Claim 50 words

The method according to claim 10 wherein said method further includes the step of flooding in layers the enclosure above the frozen body of water within said enclosure permitting each layer to freeze thus elevating the top surface of said ice structure to a predetermined elevation above the natural water-line.

Claim 14

Dependent Claim 58 words

The method according to claim 1 wherein said method further includes the step of installing refrigeration means near the surface of the body of water within said enclosure during the freezing of said body of water to prevent the surface melting of said ice during the warmer months and to maintain the ice structure in a frozen state.

Claim 15

Dependent Claim 51 words

The method according to claim 12 wherein said method further includes the step of installing a heating cable around the peripheral edge of said caissons to maintain the outer ice layer adjacent said caissons in a weakened state to reduce the load imposed on the structure by the surrounding ice formation.

Claim 16

Dependent Claim 52 words

The method according to claim 10 wherein said method further includes the step of installing an elongated tubular member through the body of water within said enclosure extending from the surface of the body of water to the sea bottom to provide access for drilling and operating equipment associated with petroleum production.

Claim 17

Dependent Claim 75 words

The method according to claim 13 wherein said offshore structure is demobilized and said caissons are removed by said method further including the steps of: circulating warm water within said caissons to free said caissons from the ice structure formed within said enclosure; removing said heat extracting means by injecting steam adjacent said means; and deballasting said caissons and disconnecting said caissons at least at one point to permit their ascension to the water surface.

Claim 18

Independent Claim 154 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and means for passively extracting heat from the water within said enclosure and the soil below said island wherein said passive heat extracting means is located within said enclosure extending into the soil below said enclosure and said passive heat extracting means is located within said caissons extending into the soil below said caissons such that said passive heat extracting means accelerates the freezing of the water within said enclosure and the soil below said caissons and enclosure in a unitary manner forming one mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island.

Claim 19

Independent Claim 154 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and means for passively extracting heat from the water within said enclosure and the soil below said island wherein said passive heat extracting means is located within said enclosure extending into the soil below said enclosure and said passive heat extracting means is located within said caissons extending into the soil below said caissons such that said passive heat extracting means accelerates the freezing of the water within said enclosure and the soil below said caissons and enclosure in a unitary manner forming one mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island.

Claim 20

Dependent Claim 25 words

The apparatus according to claim 16 wherein said passive heat extracting means comprises a plurality of enclosed elongated members having a refrigerant material enclosed therein.

Claim 21

Dependent Claim 22 words

The apparatus according to claim 16 wherein said apparatus further includes means for supporting said passive heat extracting means within said enclosure.

Claim 22

Independent Claim 170 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and a plurality of heat pipes supported within said enclosure and extending from the top of said enclosure into the bottom of the body of water below said enclosure and supported within said caissons extending from the top of said caissons through the bottom of said caissons and into the soil below said caissons wherein said heat pipes are adapted to passively remove heat from the body of water within said enclosure and the soil below said caissons and enclosure accelerating the freezing of the water and soil in a unitary manner forming a mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island by providing a larger foundational base.

Claim 23

Independent Claim 170 words

An apparatus for constructing an offshore ice island in an Arctic environment comprising: a plurality of caissons, having a top and bottom, adapted to be submerged to the bottom of a body of water and arranged in a ring configuration defining an enclosure for maintaining a body of water therein, and a plurality of heat pipes supported within said enclosure and extending from the top of said enclosure into the bottom of the body of water below said enclosure and supported within said caissons extending from the top of said caissons through the bottom of said caissons and into the soil below said caissons wherein said heat pipes are adapted to passively remove heat from the body of water within said enclosure and the soil below said caissons and enclosure accelerating the freezing of the water and soil in a unitary manner forming a mass of frozen material having a frozen soil ring below said island which improves the lateral stability of said island by providing a larger foundational base.

Claim 24

Independent Claim 177 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons, arranged in a ring configuration defining an enclosure, to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a means for passively extracting heat from the body of water within said enclosure and the soil beneath and below said caissons; (c) passively removing heat from the body of water within said enclosure by said heat extracting means to advance the freezing of the body of water within said enclosure forming said ice structure; and (d) further passively removing heat from the soil below and beneath said caissons to advance the freezing of said soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 25

Independent Claim 177 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons, arranged in a ring configuration defining an enclosure, to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a means for passively extracting heat from the body of water within said enclosure and the soil beneath and below said caissons; (c) passively removing heat from the body of water within said enclosure by said heat extracting means to advance the freezing of the body of water within said enclosure forming said ice structure; and (d) further passively removing heat from the soil below and beneath said caissons to advance the freezing of said soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 26

Independent Claim 244 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons arranged in a ring configuration defining an enclosure to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a plurality of heat pipes supported within said enclosure and caissons wherein said heat pipes within said enclosure extend from the top of said enclosure and to the bottom of the body of water below said enclosure and said heat pipes within said caissons extends from the top of said caissons through the bottom of said caissons and into the soil below said caissons wherein said heat pipes are adapted to accelerate the freezing of water within the enclosure and the soil below said enclosure and caissons; (c) passively removing heat from the body of water within said enclosure by means of said heat pipes accelerating the freezing of the body of water within said enclosure; and (d) further passively removing heat from the soil below said caissons and said enclosure by means of said heat pipes accelerating the freezing of the soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 27

Independent Claim 244 words

A method for forming an offshore ice structure in an Arctic environment comprising the steps of: (a) submerging a plurality of caissons arranged in a ring configuration defining an enclosure to the bottom of a body of water such that the height of said caissons is at least equal to the depth of said body of water; (b) installing a plurality of heat pipes supported within said enclosure and caissons wherein said heat pipes within said enclosure extend from the top of said enclosure and to the bottom of the body of water below said enclosure and said heat pipes within said caissons extends from the top of said caissons through the bottom of said caissons and into the soil below said caissons wherein said heat pipes are adapted to accelerate the freezing of water within the enclosure and the soil below said enclosure and caissons; (c) passively removing heat from the body of water within said enclosure by means of said heat pipes accelerating the freezing of the body of water within said enclosure; and (d) further passively removing heat from the soil below said caissons and said enclosure by means of said heat pipes accelerating the freezing of the soil with the water within said enclosure in a unitary manner forming a mass of frozen material having a frozen soil ring below said ice structure enlarging the foundational base of said ice structure and improving the lateral stability of said ice structure.

Claim 28

Dependent Claim 54 words

The method according to claim 21 wherein the penetration of each of said heat pipes into the bottom of the body of water below said enclosure increases radially with respect to the center of said enclosure forming a wedge-shaped mass attached to said frozen soil ring further improving the lateral stability of said island.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1983-02-04	1983-08-06	1984-02-05	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1987-02-04	1987-08-06	1988-02-05	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1991-02-04	1991-08-06	1992-02-05	$7700.00	Window Closed / Lapsed

Method and apparatus for constructing and maintaining an offshore ice island

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