US3834337A - Submarine reservoirs - Google Patents

Submarine reservoirs Download PDF

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Publication number
US3834337A
US3834337A US00334630A US33463073A US3834337A US 3834337 A US3834337 A US 3834337A US 00334630 A US00334630 A US 00334630A US 33463073 A US33463073 A US 33463073A US 3834337 A US3834337 A US 3834337A
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United States
Prior art keywords
reservoir
enclosure
liquid
auxiliary
gas
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Expired - Lifetime
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US00334630A
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English (en)
Inventor
C Bremaud
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Societe Europeenne de Propulsion SEP SA
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Societe Europeenne de Propulsion SEP SA
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    • E—FIXED CONSTRUCTIONS
    • E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
    • E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
    • E02D23/00—Caissons; Construction or placing of caissons
    • E02D23/08—Lowering or sinking caissons
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
    • B65D88/00—Large containers
    • B65D88/78—Large containers for use in or under water

Definitions

  • the present invention relates to a method of immers ing and placing on the seabed a concrete submarine reservoir of large dimensions designed to store a considerable quantity of hydrocarbon extract below water.
  • the invention relates more particularly to a method of regulating the pressure inside the reservoir during immersion, the reservoir containing a flotation gas, in which method an inert compensatory gas is introduced into the reservoir until the pressure present inside it is at least approximately equal to that of the surrounding medium in which the reservoir is immersed.
  • the invention relates equally to a concrete submarine reservoir designed to be immersed and located on the seabed.
  • Submarine reservoirs designed for location on the seabed are, as is known, filled with a flotation gas, generally air, so that they can float on the water and can be pulled along from the shipyard where they are constructed to the point where they are to be immersed.
  • the immersion operation is made possible by making the reservoir almost non-buoyant, for example by introducing a suitable quantity of seawater into the reservoir, and keeping the buoyancy of the reservoir virtually at zero during immersion.
  • the enclosure forming the reservoir' is constructed so that it can be isolated from the exterior, for example by gates; in this way, by closing the isolation gates, it is possible to keep constant the volume occupied by the flotation gas during the whole operation of immersion of the reservoir.
  • compressed air is used as the pressure-compensating gas, the source of which is located on the surface of the water and is connected to the reservoir by a connecting pipe of variable length. Since the volume of compensatory gas necessary for immersion is usually very large, the source of compressed air must be of large dimensions and therefore expensive; furthermore, the connecting pipe comprises special equipment which is therefore expensive, not only because of the variable distance between the reservoir to be fed with compressed air and the surface of the water, but also because of the generally increased maximum value of the pressure of the compressed air which is necessary to bring about regulation of the pressure mentioned, this increased pressure being withstood by the connecting pipe.
  • the invention seeks to remedy these disadvantages and provides, in particular, an economical and safe method of regulating the internal pressure of the reser voir.
  • the compensatory gas is first stored in the liquid state in an auxiliary enclosure or chamber associated with the reservoir.
  • the pressure-compensating gas is stored in compact form and it is no longer necessary to connect the concrete reservoir to a source of compensatory gas located at the surface of the water; the result of these advantages is that the immersion operation is greatly simplified.
  • the compensating gas is introduced in the liquid state into an aqueous solution, i.e. an auxiliary solution, which is contained in a chamber forming part of the reservoir and constantly in communication with the space in the reservoir filled with the flotation gas.
  • the auxiliary solution can simply be, for example, the seawater which hasalready been introduced to give the reservoir virtually no buoyancy.
  • This auxiliary solution serves as a heat source and also as a thermal damping force or heat store, which can supply the heat necessary to convert into compensatory gas the liquid introduced into the auxiliary solution.
  • This solution advantageously comprises brine which can be prepared from seawater which is introduced into the reservoir and'from the addition, for example, of a suitable quantity of sea salts. An auxiliary solution is thus obtained which has a relatively low freezing point, which is lower than that of ordinary seawater.
  • the compensatory gas advantageously comprises CO As is known, this gas can easily be liquefied and can be stored economically at low temperatures under pressure. Furthermore, CO is very soluble in water, seawater or brine. If CO is usedas compensatory gas, as is preferred, the auxiliary solution serving as the intermediate medium between the source of liquid CO and the gas-receiving volume of the reservoir enclosure is permanently supersaturated with dissolved CO and liberates gaseous CO into the gas-receiving space as soon as a quantity of liquid CO is introduced and dissolved in the auxiliary solution at a point located below the maximum level of the solution. In this way, the formation of carbonic frost or snow is avoided, which can occur as is known when carbon dioxide gas is released adiabatically.
  • the CO is preferably stored at a temperature of about 20C under a pressure of about 20 bars.
  • the method according to the invention is advantageously carried out by means of a concrete reservoir which comprises at least one enclosure whose volume is symmetrically or otherwise uniformly associated with the periphery of the concrete body of the reservoir and is filled with an auxiliary aqueous solution, at least one second enclosure which is arranged in a central zone of the concrete body of the reservoir which is filled with flotation gas and which is in constant communication with the first enclosure and a chamber filled with liquid CO which is associated with the concrete body of the reservoir and is connected to the first enclosure by means of a valved supply pipw which enters the first enclosure at a point below the maximum level of the auxiliary solution.
  • ballast material which in the'present case comprises the auxiliary aqueous solution contained in the first enclosure is distributed uniformly in relation to the periphery of the reservoir, so that the latter is very stable as regards its inclination to the horizontal and can thus be kept horizontal very easily during its immersion.
  • the ballast liquid also serves as the auxiliarysolution receiving CO in a liquid state and introducing CO in a gaseous state into the second enclosure.
  • FIG. 1 is'an axial section partially in elevation of an embodiment of the reservoir according to the invention.
  • FIG. 2 is vertical cross section of the apparatus
  • FIG. 3 is cross section taken along the line llll of FIG. 2 showingthe concentric arrangement of enclosures 2 and 3.
  • the reservoir consists of a body of concrete which comprises a principal part in the form of a cylindrical plate 1, in which enclosures are formed which are filled with brine 2 and which are uniformly distributed around the periphery of the reservoir and air-filled enclosures 3 which are located in the central zone of the reservoir and which are in constant communication with the enclosures 2 by means of apertures 5 in the upper part of the divisions separating the enclosures 2 and 3 from one another.
  • the concrete body of the reservoir further comprises a chimney 4 whose height is equal to or slightly higher than the depth of the under-water site on which the reservoir is to be placed.
  • a frame '7 is fixed by means of explodable bolts 6, which frame supports a caisson 8 containing the CO storing unit.
  • a cylindrical tank 9 filled with liquid CO at'a pressure of 20 bars and a temperature of 20C.
  • the tank 9 is of steel and is covered on its exterior with an insulating coating 10 which can resist the surrounding pressure and which consists for example of a layer offoam polyurethane covered with a layerof polyester.
  • the tank 9 is mounted on supported cradles mounted on the frame 7.
  • an evaporator 11 which is connected by means of rigid pipes equipped with gate valves, which are not illustrated, to a refrigerator unit 12 installed inside the caisson 8.
  • the refrigerator unit 12 serves to keep the liquid contained in the tank 9 at the temperature of C during the period between filling of the tank and immersion of the reservoir.
  • Filling and balancing valves 13 and 14 for the tank 9 are provided to allow liquid CO to be supplied to the tank 9 from tankers which are not illustrated and which can be loaded on the reservoir when it is in the quayside.
  • the enclosures 2 of the concrete reservoir are each connected to. the interior of the liquid CO tank 9 by means of supply pipes on which are placed pneumatic valves 19 which are controlled byelectric gate valves 18 and by explosive cutter devices 22.
  • the ends of the supply pipes each connected to an enclosure 2 are equipped with injection nozzles 20 which are entirely submerged in the brine solution. Furthermore, the tank 9 is equipped with a'level tester 23 and a pressure senser 24.
  • An electric junction box 25 is similarly provided in 9. In these are installed the valves 13 to 19, the refrigcrating unit 12 and the electric equipment 25.
  • a constant flow of CO gas through the nozzle 29 and an external purge line 30 whose outlet opening is placed at the level of the lower part of the caisson 8 allows the pressure to be kept equal between the interior of the caisson 8 and the surrounding medium.
  • a pyrotechnic valve 31 After emptying the tank 9 of liquid CO filling of the tank with seawater is effected by a pyrotechnic valve 31 and the drainage of air is effected by way of a pyrotechnic valve 32 mounted on a pipe which terminates in the tank 9 at a float valve 33.
  • the reservoir is lowered in stages in the direction of the under-water site on which it is to be placed.
  • the electric supply cable is disconnected from the refrigerator unit 12. 7
  • a suitable quantity of liquid CO is injected into the brinecontained in the enclosures 2 using the electric valves 18, so that the pressure inside the reservoir is reduced to only slightly higher than that in the surrounding medium in which the reservoir in submerged.
  • the tank 9 When the reservoir has reached the bottom of the water, the tank 9 is filled with seawater after it has been emptied of CO and the caisson 8 of the reservoir 1 is released by using the explosive cutters 22 and by detonating the bolts 6.
  • the caisson 8 rises, the purge device 30 ensuring during this ascent that the internal and external pressures acting on the walls of the caisson 8 are kept equal.
  • a reservoir according to claim 1 wherein the liquid CO chamber is removably attached to the reservoir body by means of explodable bolts, the supply pipe is associated with an explosive cutter device and the CO chamber is provided with a variable buoyancy flotation device.
  • a reservoir according to claim 2 wherein a control valve in the CO supply pipe, the flotation device and the explodable bolts and cutter devices are associated with electromagnetic control members connected by a cable to a single control station located above the level of the sea.
  • a method of immersing a buoyant reservoir into a body of liquid and controlling the pressure in the interior of the reservoir which comprises introducing an aqueous solution into a first enclosure within said reservoir, in amount sufficient to counteract the initial buoyancy thereof, introducing a liquefied gas into an auxiliary enclosure detachably attached to said reservoir, lowering the reservoir in stages into the body of liquid, injecting said liquefied gas in stages into said first enclosure, said reservoir containing a third enclosure containing a flotation gas, said third enclosure being in communication with said first enclosure, said liquefied gas being soluble in said aqueous solution, the injection of said liquefied gas into said aqueous solution being regulated to maintain the pressure within the reservoir slightly higher than the surrounding medium, and when the reservoir has reached the bed of said body of liquid, removing said auxiliary enclosure from the reservoir.
  • auxiliary solution comprises seawater or brine.

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  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Mining & Mineral Resources (AREA)
  • Paleontology (AREA)
  • Civil Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Filling Or Discharging Of Gas Storage Vessels (AREA)
US00334630A 1972-04-19 1973-02-22 Submarine reservoirs Expired - Lifetime US3834337A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7213823A FR2181164A5 (Direct) 1972-04-19 1972-04-19

Publications (1)

Publication Number Publication Date
US3834337A true US3834337A (en) 1974-09-10

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ID=9097164

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Application Number Title Priority Date Filing Date
US00334630A Expired - Lifetime US3834337A (en) 1972-04-19 1973-02-22 Submarine reservoirs

Country Status (6)

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US (1) US3834337A (Direct)
JP (1) JPS5632194B2 (Direct)
CA (1) CA979674A (Direct)
DE (1) DE2312014C3 (Direct)
FR (1) FR2181164A5 (Direct)
GB (1) GB1387374A (Direct)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7267072B2 (en) * 2002-08-01 2007-09-11 Mao Zhang Dry cargo submarine with air-charge cargo hold
CN102888846A (zh) * 2012-09-29 2013-01-23 宁波科宁爆炸技术工程有限公司 密实水下抛石基床的施工方法
WO2017168144A1 (en) * 2016-03-29 2017-10-05 Sllp 134 Limited Method for installing a subsea structure
CN111114726A (zh) * 2019-12-30 2020-05-08 武昌船舶重工集团有限公司 压载水舱的超压保护装置

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0287195U (Direct) * 1988-12-23 1990-07-10
JP3106575B2 (ja) * 1991-07-30 2000-11-06 石川島播磨重工業株式会社 深海用均圧装置

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3340842A (en) * 1966-04-06 1967-09-12 Charles A Winslow Marine safety systems
US3376588A (en) * 1965-10-24 1968-04-09 Chicago Bridge & Iron Co Buoy with buoyancy produced by liquefied gas vaporization

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3376588A (en) * 1965-10-24 1968-04-09 Chicago Bridge & Iron Co Buoy with buoyancy produced by liquefied gas vaporization
US3340842A (en) * 1966-04-06 1967-09-12 Charles A Winslow Marine safety systems

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7267072B2 (en) * 2002-08-01 2007-09-11 Mao Zhang Dry cargo submarine with air-charge cargo hold
CN102888846A (zh) * 2012-09-29 2013-01-23 宁波科宁爆炸技术工程有限公司 密实水下抛石基床的施工方法
WO2017168144A1 (en) * 2016-03-29 2017-10-05 Sllp 134 Limited Method for installing a subsea structure
CN111114726A (zh) * 2019-12-30 2020-05-08 武昌船舶重工集团有限公司 压载水舱的超压保护装置
CN111114726B (zh) * 2019-12-30 2021-02-09 武昌船舶重工集团有限公司 压载水舱的超压保护装置

Also Published As

Publication number Publication date
GB1387374A (en) 1975-03-19
CA979674A (en) 1975-12-16
JPS5632194B2 (Direct) 1981-07-25
FR2181164A5 (Direct) 1973-11-30
DE2312014B2 (de) 1978-05-18
DE2312014C3 (de) 1979-01-04
DE2312014A1 (de) 1973-10-25
JPS4916908A (Direct) 1974-02-14

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