Underwater oil depot tank and construction method

Abstract

The underwater oil depot tank and the construction method thereof provided by the application comprise a soft tank body and a low-melting-point alloy material, the soft tank body is made of flexible material, and the low-melting-point alloy material can be cast on site. Since the soft tank body can be prefabricated and folded, the volume is greatly reduced. The low-melting-point alloy material is injected into the interlayer to play a supporting and counterweight role. The two can be separately towed to a predetermined position in the far sea. Through on-site rapid construction, the underwater oil depot tank is jointly formed, thereby solving the contradictory problems that the traditional tank body is too large to be towed in the far sea and the tank body made of traditional material is difficult to be constructed on the sea surface in the far sea.

Description

TECHNICAL FIELD

[0001] The present application relates to the oil and gas storage and transportation technical field, in particular to an underwater oil depot tank body and a construction method. BACKGROUND

[0002] There are three ways of offshore oil storage, i.e., on-water storage, water surface storage and underwater storage. The first two ways are relatively mature, but the on-water storage platform has a high cost, and the oil storage capacity cannot be too large due to the bearing capacity limitation of the support structure. The water surface storage is greatly affected by external waves, currents, ice and the like. In comparison, the underwater storage has many advantages, and has been successfully applied abroad. Because the oil storage tank is located below the water surface, it is isolated from fire and lightning, the oil and gas loss is small, and it has natural explosion-proof performance. At the same time, it avoids the influence of wave force, and the tank capacity is not limited, so it has a large oil storage capacity.

[0003] The traditional underwater storage tank shell is generally made of prestressed reinforced concrete or stainless steel, and is constructed on land and then towed to the predetermined sea area for sinking after being filled with water. This is relatively easy to achieve in the near sea. At present, oil field development is developing towards the deep sea and the far sea. Since the predetermined sea area is far from the mainland, the volume of the storage tank is large, and at this time the towing cost is too high to be feasible, and the towing process faces complex and harsh sea conditions, and there is a safety risk.

[0004] China has vast sea areas, especially the South China Sea has many islands far from oil ports, and the cost and time of oil supply are high. If an underwater oil depot is built near the islands, it can meet the needs of life and training of the stationed troops or the supply needs of the ocean fishing vessels during peacetime, and can be mobilized and transferred to supply fuel for the front-line ships / fighters during wartime, greatly expanding the combat radius. Therefore, it is necessary to develop a material and construction technology that can meet the strength requirements and be constructed on site to meet the construction needs of the underwater oil depot in the far sea. SUMMARY

[0005] In view of this, it is necessary to provide a tank body and a construction method that can be constructed on a large scale in the far sea to overcome the defects of the traditional tank body that is too large to be towed in the far sea and the traditional material tank body that is difficult to be constructed on the sea surface in the far sea.

[0006] To solve the above problems, the technical scheme adopted by the present application is as follows:

[0007] One of the objects of the present application is to provide an underwater oil depot tank body comprising a soft tank body and a low-melting-point alloy material. The soft tank body comprises an inner wall and an outer wall, the inner wall and the outer wall form a sandwich, the inner wall and the outer wall are both flexible materials, an injection port is formed on the inner wall, at least one feed port and at least one exhaust / liquid port are formed on the sandwich, and the low-melting-point alloy material can be injected into the sandwich through the feed port.

[0008] In some embodiments, the flexible material comprises aramid fiber, including the Kevlar series.

[0009] In some embodiments, the low-melting alloy material has a melting point between 70-90℃.

[0010] In some embodiments, the low-melting alloy material comprises a ternary alloy or a quaternary alloy, which is composed of bismuth, indium, tin, lead, and further added with at least one of zinc or copper or carbon.

[0011] In some embodiments, the low-melting alloy material comprises the following content of elements: bismuth content of 30-60 mass%, indium content of 1-30%, tin content of 10-20 mass%, lead content of 10-35 mass%, and the balance of zinc or copper or carbon.

[0012] In some embodiments, the ternary alloy has the following composition Bi:In:Sn ~ 57:26:17, and the balance of zinc, and the quaternary alloy has the following composition Bi:In:Sn:Pb ~ 49:21:12:18, and the balance of zinc.

[0013] In some embodiments, the low-melting alloy material has a density of 8-10 g / ml.

[0014] In some embodiments, the inner side of the interlayer is attached with an electric heating wire, and a plurality of temperature measuring devices are arranged.

[0015] In some embodiments, the thickness of the interlayer is between 10-500 mm.

[0016] In some embodiments, the outer side of the soft tank body is further sprayed with polyurea.

[0017] The second object of the present application provides a construction method of the underwater oil depot tank body, comprising the following steps:

[0018] Turning on the soft tank body to make it swell and form, and the soft tank body floats on the sea surface;

[0019] Spraying polyurea on the outer side of the soft tank body to shape the soft tank body;

[0020] Injecting deoxygenated water into the interlayer through the feed port, and the air in the interlayer is discharged from the exhaust / liquid port;

[0021] Injecting the low-melting alloy material in a molten state into the interlayer through the feed port;

[0022] The deoxidized water is discharged from the interlayer exhaust / liquid port in succession until the low-melting-point alloy material fills the interlayer;

[0023] Sea water is injected from the injection port to cool and form the shell of the soft tank body, the injection amount of the sea water is controlled, and the upper part of the soft tank body is kept above the sea level to complete subsequent construction.

[0024] In some embodiments, in the step of injecting deoxidized water into the interlayer through the feed port and discharging air in the interlayer from the exhaust / liquid port, the deoxidized water is continuously heated by heating wires attached to the inner wall of the interlayer to maintain the temperature of the deoxidized water at 90-95°C.

[0025] In some embodiments, in the step of injecting the low-melting-point alloy material in a molten state into the interlayer through the feed port, hot nitrogen gas is used to drive the injection of the low-melting-point alloy material into the interlayer through the feed port.

[0026] In some embodiments, before the step of injecting the low-melting-point alloy material in a molten state into the interlayer through the feed port, the low-melting-point alloy material is subjected to a heating treatment to make it in a molten state.

[0027] The technical scheme provided by the present application has the following beneficial effects:

[0028] The underwater oil depot tank body provided by the present application comprises a soft tank body and a low-melting-point alloy material. The soft tank body is made of flexible material, and the low-melting-point alloy material can be cast on site. Since the soft tank body can be prefabricated and folded, its volume is greatly reduced. The low-melting-point alloy material injected into the interlayer serves as support and counterweight. The two can be separately towed to a predetermined location in the open sea and jointly form an underwater oil depot tank body through on-site construction, thereby solving the contradictory problems of the huge size of the traditional tank body which is difficult to tow in the open sea and the difficulty of constructing the tank body made of traditional materials on the sea surface. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application or the prior art description. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 The structural schematic diagram of the soft tank body provided for Embodiment 1 of the present application.

[0031] Figure 2 The structural schematic diagram of the soft tank body provided for Embodiment 1 of the application.

[0032] Figure 3 The step flow chart of the construction method of the tank body provided in Embodiment 2 of the present application. DETAILED DESCRIPTION

[0033] Embodiments of the present application are described in detail below with reference to the accompanying drawings, in which the same or similar elements or elements having the same or similar functions are denoted by the same or similar reference numerals throughout. The embodiments described below by reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as limiting the present application.

[0034] In the description of the present application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0035] In addition, the terms "first", "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features referred to. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0036] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments.

[0037] Embodiment 1

[0038] Please refer to Figure 1 and Figure 2 A structural schematic diagram of an underwater oil depot tank body provided in an embodiment of the present application, comprising: a soft tank body 110 and a low-melting-point alloy material, and the implementation mode of each component is described in detail below.

[0039] The soft tank body 110 comprises an inner wall 11 and an outer wall 12. The inner wall 11 and the outer wall 12 form a sandwich 13, and the inner wall 11 and the outer wall 12 are both flexible materials.

[0040] In the present embodiment, the soft tank body 110 is made of a flexible material, can be prefabricated and foldable, so that the volume is greatly reduced, facilitating transportation, and making it feasible to tow in the open sea.

[0041] Preferably, the flexible material comprises aramid fiber, which has excellent properties such as super high strength, high modulus, high temperature resistance, acid and alkali resistance, etc.

[0042] The inner wall 11 is provided with an injection port 14. The interlayer 13 is provided with at least one feeding port 15 and at least one exhaust / liquid port 16. When the size of the tank is large, multiple feeding ports and exhaust / liquid ports can be designed on the interlayer 13.

[0043] The low-melting-point alloy material can be injected into the interlayer 13 through the feeding port 15.

[0044] In this embodiment, the melting point of the low-melting-point alloy material is between 70-90°C. It can be understood that, due to the low melting point of the low-melting-point alloy material, it can be brought into a molten state by direct heating, and the casting process can be realized by boiling water only, without consuming too much energy, which is easy to realize in a far sea environment, and is within the temperature range that the soft tank material can tolerate, and has low construction difficulty. In actual use, it can be prepared in a granular form for standby.

[0045] In this embodiment, the low-melting-point alloy material comprises a ternary alloy or a quaternary alloy, which is composed of bismuth, indium, tin, and lead. The ternary alloy or quaternary alloy is further added with at least one of zinc, copper, or carbon.

[0046] Preferably, the low-melting-point alloy material comprises the following contents of elements: bismuth content of 30-60 mass%, indium content of 1-30%, tin content of 10-20 mass%, lead content of 10-35 mass%, and the balance of zinc, copper, or carbon.

[0047] Further, the ternary alloy has the following composition Bi:In:Sn~57:26:17, and is doped with the balance of zinc; the quaternary alloy has the following composition Bi:In:Sn:Pb~49:21:12:18, and is doped with the balance of zinc, at which time the alloy strength, melting point, and construction difficulty of the low-melting-point alloy material are most suitable.

[0048] In this embodiment, the density of the low-melting-point alloy material is 8-10 g / ml.

[0049] In this embodiment, the inner side of the interlayer 13 is attached with an electric heating wire, and a plurality of temperature measuring devices are arranged.

[0050] It can be understood that, under the action of the electric heating wire, the interlayer 13 can be kept within a suitable temperature range, and the temperature can be displayed by the temperature measuring device for operation.

[0051] In this embodiment, the thickness of the interlayer 13 is between 10-500 mm. It can be understood that the thickness of the interlayer 13 is determined according to the strength check.

[0052] In the embodiment, the outer side of the soft tank body 110 is also sprayed with polyurea. When the soft tank body 110 is inflated and swells, the outer side is sprayed with polyurea to obtain an initial rigid shell, which is beneficial to subsequent construction operations.

[0053] The underwater oil depot tank body provided by the above-mentioned embodiments of the present application comprises a soft tank body 110 and a low-melting-point alloy material. The soft tank body 110 is made of flexible material, and the low-melting-point alloy material can be cast on site. Since the soft tank body can be prefabricated and folded, the volume is greatly reduced. The low-melting-point alloy material is injected into the interlayer to play a supporting and counterweight role. The two can be separately towed to a predetermined position in the open sea, and jointly constitute an underwater oil depot tank body through on-site construction, thereby solving the contradictory problems that the traditional tank body is too large to be towed in the open sea and the traditional material tank body is difficult to be constructed on the open sea.

[0054] Embodiment 2

[0055] Please refer to Figure 3 The step flow chart of the construction method of the underwater oil depot tank body provided by the embodiments of the present application comprises the following steps:

[0056] Step S110: Turn on the soft tank body 110 to make it swell and form, and the soft tank body 110 floats on the sea surface.

[0057] Specifically, when the soft tank body 110 reaches the predetermined position, compressed air is used to press the soft oil tank to make it swell and form, and at this time the tank body floats on the sea surface (similar to a swimming ring).

[0058] Step S120: Spray polyurea on the outer side of the soft tank body 110 to shape the soft tank body.

[0059] When the soft tank body 110 is inflated and swells, the outer side is sprayed with polyurea to obtain an initial rigid shell, which is beneficial to subsequent construction operations.

[0060] Step S130: Inject deoxidized water into the interlayer 13 through the feed port 15, and the air in the interlayer 13 is discharged from the exhaust / liquid port 16.

[0061] Specifically, about 100℃ deoxidized water is injected into the interlayer 13 through the feed port, and the air in the interlayer 13 is discharged from the interlayer exhaust / liquid port 16. The heating wire attached to the inner wall of the interlayer 13 is continuously heated to ensure that the temperature of the deoxidized water is maintained at 90-95℃, and the oxygen content of the deoxidized water is less than 0.1mg / L.

[0062] Step S140: Inject the low-melting-point alloy material in a molten state into the interlayer 13 through the feed port 15.

[0063] Specifically, the low-melting alloy material in molten state is injected into the interlayer 13 through the feeding port 15 by using the shipborne hoisting equipment, and hot nitrogen gas is used to drive the low-melting alloy material, if necessary, so as to shorten the feeding time.

[0064] In some embodiments, before the step of injecting the low-melting alloy material in molten state into the interlayer 13 through the feeding port 15, the following step is further included: heating the low-melting alloy material so that the low-melting alloy material is in molten state.

[0065] Step S150: the deoxidized water is successively discharged from the exhaust / liquid port 16 until the low-melting alloy material fills the interlayer 13.

[0066] It can be understood that, since the density of the low-melting alloy material (about 9-10 g / ml) is much greater than that of water, the low-melting alloy material will quickly sink to the bottom, and the deoxidized water is successively discharged from the exhaust / liquid port 16 of the interlayer 13 until the low-melting alloy material fills the interlayer 13.

[0067] Step S160: sea water is injected from the injection port 14 to cool and form the shell of the soft tank body 110, the injection amount of the sea water is controlled, the upper part of the soft tank body 110 is kept above the sea surface, and subsequent construction is completed.

[0068] It can be understood that the heating wire in the interlayer 13 stops heating, and sea water is injected from the injection port 14 to quickly cool and form the shell; then the injection amount of the sea water is increased, the soft tank body 110 also gradually sinks, and the external sea water can also be accelerated to cool; by controlling the injection amount of the sea water, the upper part of the soft tank body 110 is kept above the water surface, and subsequent construction is completed.

[0069] In the embodiment, the underwater oil storage adopts the oil-water displacement process, and the oil is drained and then pumped into water, and the soft tank body 110 always maintains the condition of being filled with liquid, so that the great buoyancy when the tank is emptied is overcome, and the pressure difference between the inner wall and the outer wall of the tank is also small, so that the strength of the low-melting alloy material, although lower than that of stainless steel, still meets the requirements of the underwater oil storage working condition.

[0070] It can be understood that, after the shell of the soft tank body 110 is completely cooled (the temperatures of the temperature measuring points in the interlayer approach the ambient temperature), the reserved pipe openings are polished and encapsulated, and residue treatment is performed; tank melting casting condition inspection is performed to confirm the integrity of the shell; and finally, other facilities installation of the underwater oil tank is completed.

[0071] The underwater oil depot tank construction method provided in the above embodiments of this application uses a flexible tank made of a flexible material. The low-melting-point alloy material can be cast on-site. Since the flexible tank can be prefabricated and foldable, its volume is greatly reduced. The low-melting-point alloy material injected into the interlayer plays a supporting and counterweight role. Both can be towed to a predetermined location in the open sea and jointly constructed on-site to form the underwater oil depot tank. This solves the contradiction between the large size of traditional tanks, which are difficult to tow in the open sea, and the difficulty of constructing tanks made of traditional materials on the surface of the open sea.

[0072] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0073] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A construction method for an underwater oil depot tank, characterized in that, The construction method is carried out using an underwater oil depot tank, which includes a flexible tank and a low-melting-point alloy material. The flexible tank includes an inner wall and an outer wall, which form a sandwich layer. Both the inner wall and the outer wall are made of flexible materials. An injection port is provided on the inner wall. At least one feed port and at least one vent / liquid port are provided on the sandwich layer. The low-melting-point alloy material can be injected into the sandwich layer through the feed port. The construction method includes the following steps: The soft container is opened, and compressed air is used to inflate it into shape, causing the soft container to float on the sea surface; Polyurea is sprayed onto the outside of the flexible container to shape it. Deoxygenated water is injected into the interlayer through the feed inlet, and the air inside the interlayer is discharged from the exhaust / liquid outlet. Molten low-melting-point alloy material is injected into the interlayer through the feed port; The deoxygenated water is discharged continuously from the vent / liquid port of the interlayer until the low melting point alloy material fills the interlayer. Seawater is injected through the inlet to cool and solidify the shell of the flexible tank. The amount of seawater injected is controlled to keep the upper part of the flexible tank above the seawater surface, so as to complete subsequent construction.

2. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The flexible material includes aramid fibers.

3. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The melting point of the low-melting-point alloy material is between 70 and 90°C.

4. The construction method for underwater oil depot tanks as described in claim 3, characterized in that, The low-melting-point alloy material includes ternary alloys or quaternary alloys, which are composed of bismuth, indium, tin, and lead, and further contain at least one of zinc, copper, or carbon.

5. The construction method for underwater oil depot tanks as described in claim 4, characterized in that, The low-melting-point alloy material comprises the following elements: bismuth content of 30-60 mass%, indium content of 1-30 mass%, tin content of 10-20 mass%, lead content of 10-35 mass%, and the balance of zinc, copper, or carbon.

6. The construction method for underwater oil depot tanks as described in claim 4, characterized in that, The ternary alloy has the following composition: Bi:In:Sn ~ 57:26:17, with the balance being zinc; the quaternary alloy has the following composition: Bi:In:Sn:Pb ~ 49:21:12:18, with the balance being zinc.

7. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The density of the low-melting-point alloy material is 8-10 g / ml.

8. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The inner side of the interlayer is covered with an electric heating wire and equipped with several temperature measuring devices.

9. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The thickness of the interlayer is between 10 and 500 mm.

10. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, In the step of injecting deoxygenated water into the jacket through the feed port and expelling the air in the jacket from the exhaust / liquid port, the method further includes using a heating wire attached to the inner wall of the jacket to continuously heat the jacket and ensure that the temperature of the deoxygenated water is maintained at 90~95℃.

11. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, The step of injecting molten low-melting-point alloy material into the interlayer through the feed port further includes using hot nitrogen to drive the injection of the low-melting-point alloy material into the interlayer through the feed port.

12. The construction method for underwater oil depot tanks as described in claim 1, characterized in that, Before the step of injecting molten low-melting-point alloy material into the interlayer through the feed port, the following step is also included: heating the low-melting-point alloy material to bring it into a molten state.

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