Controllable dissolution device and method for salt cavern cavity-making outer pipe and inner pipe

Abstract

The invention discloses a controllable dissolution device and method for an outer pipe and an inner pipe of salt cavern cavity construction, and relates to the technical field of salt rock water dissolution cavity construction. The lower cavity making pipe can be accurately dissolved according to needs in the cavity making process, and the problems that in the cavity making pipe lifting process, operation is difficult, and cost is high are solved. The device comprises an annular barrel, a first spray head assembly and a second spray head assembly, wherein the first spray head assembly and the second spray head assembly are arranged on the annular barrel; an annular cavity of the annular cylinder is divided into a first annular cavity and a second annular cavity; the first spray head assembly communicates with the first annular cavity and faces the inner wall of the cavity making outer pipe; the second spray head assembly communicates with the second annular cavity and faces the outer wall of the cavity forming inner pipe. The invention further provides a dissolving method based on the dissolving device.

Description

Technical Field

[0001] The present application relates to the technical field of salt rock water-soluble cavern making, and in particular to a device and method for controllable dissolution of an outer tube and an inner tube of a salt cavern making cavern. Background Art

[0002] Salt cavern gas storage refers to a facility that uses underground cavities formed by water-soluble salt mining in underground salt layers or salt domes to store natural gas. Due to its strong gas storage capacity, high safety, high flexibility, good economic benefits, and environmental friendliness, countries around the world are currently vigorously developing salt cavern gas storage. In addition, due to the rapid development of my country's economy and society, natural gas consumption continues to rise, and more and more people are using salt caverns to store natural gas.

[0003] Salt cavern gas storage can be obtained by creating cavities in underground salt layers. Figure 1 The cavity making device used in cavity making includes a cavity making pipe 01 and a casing string 02. The cavity making pipe 01 includes an inner cavity making pipe 011 and an outer cavity making pipe 012, and the bottom end of the inner cavity making pipe 011 is lower than the bottom end of the outer cavity making pipe 012. The cavity making method is: drill a vertical well, then fix the casing string 02 on the inner wall of the vertical well, and lower the cavity making pipe 01 through the casing string 02. When the cavity making starts, water is injected through the annulus of the inner cavity making pipe 011 and the outer cavity making pipe 012, and the salt layer is dissolved in the water to form salt water, and the salt water is returned from the inner pipe to the outside of the well. The bottom end of the inner cavity making pipe 011 is lower than the bottom end of the outer cavity making pipe 012, so that the concentration of the discharged salt water is higher, and the utilization rate of water is improved. However, during the cavity making process, the cavity making tube 01 needs to be lifted up several times to achieve layer-by-layer operation. The process needs to keep the positional relationship between the lower ends of the cavity making inner tube 011 and the cavity making outer tube 012, that is, the cavity making inner tube 011 and the cavity making outer tube 012 need to be lifted up layer by layer and synchronously. At present, it mainly depends on experience and practice. The above method usually requires the professional knowledge of professional engineers and lifting devices. It is difficult for operators without professional knowledge to operate, and the lifting cost is relatively high. Summary of the invention

[0004] The embodiments of the present application provide a device and method for controllable dissolution of an outer tube and an inner tube of a salt cavern, which can accurately dissolve the lower cavern tube as needed during the cavern making process, thereby solving the problem of difficult operation and high cost during the lifting of the cavern tube.

[0005] To achieve the above-mentioned purpose, on the one hand, an embodiment of the present application provides a device for controllable dissolution of an outer tube and an inner tube of a salt cavern cavity, comprising an annular cylinder and a first nozzle assembly and a second nozzle assembly arranged on the annular cylinder; the annular cavity of the annular cylinder is divided into a first annular cavity and a second annular cavity; the first nozzle assembly is connected to the first annular cavity and faces the inner wall of the outer tube of the cavity; the second nozzle assembly is connected to the second annular cavity and faces the outer wall of the inner tube of the cavity.

[0006] Furthermore, the first annular cavity and the second annular cavity are arranged vertically.

[0007] Furthermore, the first nozzle assembly is arranged on the outer wall surface of the annular cylinder and corresponds to the position of the first annular cavity; the second nozzle assembly is arranged on the bottom wall surface of the annular cylinder.

[0008] Furthermore, the first nozzle assembly includes a plurality of first nozzles evenly distributed along the circumference of the annular cylinder; the second nozzle assembly includes a plurality of second nozzles evenly distributed along the circumference of the annular cylinder.

[0009] Furthermore, the longitudinal cross-section of the first nozzle is trapezoidal.

[0010] Furthermore, the second nozzle includes a nozzle body and a vertical connecting section connected between the nozzle body and the annular cylinder.

[0011] Furthermore, the longitudinal cross-section of the nozzle body is trapezoidal; and the vertical connecting section is a rectangular tube.

[0012] Furthermore, both the first annular cavity and the second annular cavity are provided with liquid inlets.

[0013] On the other hand, an embodiment of the present application also provides a dissolution method based on the above-mentioned salt cavern cavity outer tube and inner tube controllable dissolution device, comprising the following steps: S1, collecting the cavity data of the salt cavern reservoir group and preprocessing the cavity data of the salt cavern reservoir group; the cavity data of the salt cavern reservoir group includes the number of cavities, the depth of the injection and production gas pipeline of each cavity, and the connectivity of each cavity and data of related influencing factors; S2, calculating the length of the cavity tube according to the preprocessed data, and adjusting the distance between the first nozzle assembly and the second nozzle assembly in the dissolution device according to the calculation result; S3, injecting a first soluble solution that can dissolve the cavity outer tube and the cavity outer tube coating into the first annular cavity and the second annular cavity of the dissolution device; S4, connecting the dissolution device under the driving rotating machine; S5, lowering the dissolution device to the first preset dissolution position, which corresponds to the position of the lowest section to be dissolved; S6, starting the driving rotating machine and opening the first nozzle assembly and the second nozzle assembly The switch of the dissolving device rotates and works, and the first nozzle assembly sprays the first soluble solution outward to dissolve the coating of the outer tube of the cavity; the second nozzle assembly sprays the first soluble solution inward to dissolve the coating of the inner tube of the cavity; S7, after the coating of the lowermost section of the outer tube of the cavity and the outer tube of the cavity is dissolved, stop driving the rotating machine and turn off the switches of the first nozzle assembly and the second nozzle assembly, and then inject the second soluble solution that can dissolve the outer tube of the cavity and the outer tube of the cavity into the first annular cavity and the second annular cavity; the second soluble solution can dissolve aluminum alloy; S8, after the lowermost section of the outer tube of the cavity and the outer tube of the cavity are "cut" and fall into the salt cavern below to be dissolved by brine, lift the dissolving device to the second preset dissolving position; the second preset dissolving position is located above the first preset dissolving position and corresponds to the position of the second section below; S9, repeat steps 6 and 7 until the outer tube of the cavity and the inner tube of the cavity are all cut and fall into the salt cavern below except the uppermost section, and then lift the dissolving device.

[0014] Compared with the prior art, this application has the following beneficial effects:

[0015] 1. Compared with the traditional method, the device for controllable dissolution of the outer and inner tubes of the salt cavern cavity formation in the embodiment of the present application requires professionals to use a lifting device to lift the inner and outer tubes of the cavity formation, which omits the process of lifting the cavity formation tube, so that the dissolution can be achieved directly within a controllable range.

[0016] 2. The device for controllable dissolution of the outer and inner tubes of the salt cavern cavity-forming embodiment of the present application has strong flexibility and accuracy, and can accurately dissolve the inner and outer tubes of the cavity-forming cavity-forming at the same time. During the dissolution process, the height difference between the inner and outer tubes can be adjusted according to needs, providing a more accurate, efficient and economical solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 It is a structural schematic diagram of an existing cavity-making device;

[0019] Figure 2 A schematic diagram of the three-dimensional structure of a device for controlling the dissolution of an outer tube and an inner tube for creating a salt cavern according to an embodiment of the present application at one angle;

[0020] Figure 3 This is a schematic diagram of the three-dimensional structure of the device for controlling the dissolution of the outer tube and inner tube of the salt cavern formation according to the embodiment of the present application from another angle;

[0021] Figure 4 A perspective view of a device for controlling the dissolution of an outer tube and an inner tube of a salt cavern according to an embodiment of the present application;

[0022] Figure 5 This is a cross-sectional view of a device for controlling the dissolution of an outer tube and an inner tube of a salt cavern according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] In the description of the present application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. For ordinary technicians in this field, they can understand the specific meanings of the above terms in this application according to specific circumstances.

[0026] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" can explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more.

[0027] Reference Figures 2 to 5 An embodiment of the present application provides a device for controllable dissolution of an outer tube and an inner tube of a salt cavern formation, comprising an annular cylinder 1 and a first nozzle assembly 2 and a second nozzle assembly 3 arranged on the annular cylinder 1.

[0028] The annular cylinder 1 is a circular annular cylinder. The annular cavity of the annular cylinder 1 is divided into a first annular cavity 11 and a second annular cavity 12. The first annular cavity 11 and the second annular cavity 12 are arranged up and down. The first annular cavity 11 and the second annular cavity 12 are both provided with liquid inlets.

[0029] The first nozzle assembly 2 is arranged on the outer wall surface of the annular cylinder 1 and corresponds to the position of the first annular cavity 11. The first nozzle assembly 2 includes four first nozzles 21. The four first nozzles 21 are evenly distributed along the circumference of the annular cylinder 1. The four first nozzles 21 are all connected to the first annular cavity 11 and face the inner wall of the cavity outer tube. The longitudinal section of the first nozzle 21 is trapezoidal.

[0030] The second nozzle assembly 3 is arranged on the bottom wall surface of the annular cylinder 1. The second nozzle assembly 3 includes four second nozzles. The four second nozzles are evenly distributed along the circumference of the annular cylinder 1. The four second nozzles are all connected to the second annular cavity 12 and face the outer wall of the cavity-making inner tube. The second nozzle includes a nozzle body 31 and a vertical connecting section 32 connected between the nozzle body 31 and the annular cylinder 1. The longitudinal cross-section of the nozzle body 31 is trapezoidal. The vertical connecting section 32 is a rectangular tube with adjustable length, such as a telescopic tube.

[0031] On the other hand, an embodiment of the present application further provides a dissolution method based on the above-mentioned salt cavern formation outer tube and inner tube controllable dissolution device, comprising the following steps:

[0032] S1. Manually collect the cavity data of the salt cavern storage group and pre-process the cavity data of the salt cavern storage group; the cavity data of the salt cavern storage group includes the number of cavities, the depth of the injection and production gas pipeline of each cavity, the connectivity of each cavity and the data of related influencing factors.

[0033] S2. Calculate the length of the cavity tube according to the preprocessed data, and adjust the distance between the first nozzle assembly 2 and the second nozzle assembly 3 in the size of the dissolving device according to the calculation result. In addition, the accuracy and prediction ability of the device can be evaluated by comparing the difference between the predicted results and the actual results of the device, and adjustments can be made for devices with poor performance.

[0034] S3. Inject the first soluble liquid that can dissolve the outer tube and the coating of the outer tube into the first annular cavity 11 and the second annular cavity 12 of the dissolving device. It should be noted that: during the mining process, the materials used for the inner tube and the outer tube are soluble aluminum alloys. However, since the soluble aluminum alloy may be dissolved during the water injection and brine drainage process, it is necessary to coat the inner and outer walls of the inner tube and the inner wall of the outer tube in advance. The first soluble liquid is a soluble liquid that can dissolve the coating.

[0035] S4. Connect the dissolving device under the driving rotating machine. The driving rotating machine drives the dissolving device to rotate during spraying, so that the spraying area can be more uniform.

[0036] S5. Lower the dissolving device to a first preset dissolving position, which corresponds to the position of the lowest section to be dissolved.

[0037] S6. Start the driving rotating machine and turn on the switches of the first nozzle assembly 2 and the second nozzle assembly 3. The dissolving device rotates and works. The first nozzle assembly 2 sprays the first soluble solution outward to dissolve the coating of the outer tube of the cavity making; the second nozzle assembly 3 sprays the first soluble solution inward to dissolve the coating of the inner tube of the cavity making.

[0038] S7, after the coating of the lowermost section of the outer tube and the outer tube is dissolved, stop driving the rotary machine and turn off the switches of the first nozzle assembly 2 and the second nozzle assembly 3, and then inject the second soluble solution that can dissolve the outer tube and the outer tube into the first annular cavity 11 and the second annular cavity 12; the second soluble solution can dissolve the aluminum alloy. The second soluble solution can be the brine on site (the dissolution rate of the soluble aluminum alloy increases with the increase of the concentration of NaCl, and the temperature in the salt cavern is high, which meets the optimal temperature conditions for dissolution).

[0039] S8. After the lowest section of the cavity-forming outer tube and the cavity-forming outer tube are "cut" and fall into the salt cavern below to be dissolved by the brine in the salt cavern, the dissolving device is lifted to the second preset dissolving position; the second preset dissolving position is located above the first preset dissolving position and corresponds to the position where the second section is lowered.

[0040] S9, repeating steps 6 and 7 until all the sections of the outer cavity tube and the inner cavity tube except the uppermost section are cut and fall into the salt cavern below, and then the dissolving device can be taken out.

[0041] The above are only specific implementations of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A device for controlling the dissolution of the outer tube and inner tube of a salt cavern, characterized in that: It includes an annular cylinder and a first nozzle assembly and a second nozzle assembly arranged on the annular cylinder; the annular cavity of the annular cylinder is divided into a first annular cavity and a second annular cavity; the first nozzle assembly is connected to the first annular cavity and faces the inner wall of the outer cavity tube; the second nozzle assembly is connected to the second annular cavity and faces the outer wall of the inner cavity tube.

2. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 1, characterized in that: The first annular cavity and the second annular cavity are arranged vertically.

3. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 2, characterized in that: The first nozzle assembly is arranged on the outer wall surface of the annular cylinder and corresponds to the position of the first annular cavity; the second nozzle assembly is arranged on the bottom wall surface of the annular cylinder.

4. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 3, characterized in that: The first nozzle assembly includes a plurality of first nozzles uniformly distributed along the circumference of the annular cylinder; the second nozzle assembly includes a plurality of second nozzles uniformly distributed along the circumference of the annular cylinder.

5. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 4, characterized in that: The longitudinal cross section of the first nozzle is trapezoidal.

6. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 5, characterized in that: The second nozzle comprises a nozzle body and a vertical connection section connected between the nozzle body and the annular cylinder; the length of the vertical connection section is adjustable.

7. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 6, characterized in that: The longitudinal section of the nozzle body is trapezoidal; the vertical connecting section is a rectangular tube.

8. The device for controlling the dissolution of the outer tube and inner tube of the salt cavern according to claim 1, characterized in that: The first annular cavity and the second annular cavity are both provided with liquid inlets.

9. A dissolution method based on the device for controllable dissolution of the outer tube and inner tube of a salt cavern according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Collect the cavity data of the salt cavern storage group and pre-process the cavity data of the salt cavern storage group; the cavity data of the salt cavern storage group includes the number of cavities, the depth of the injection and production gas pipeline of each cavity, the connectivity of each cavity and the data of related influencing factors; S2, calculating the length of the cavity-making tube according to the preprocessed data, and adjusting the distance between the first nozzle assembly and the second nozzle assembly in the dissolving device according to the calculation result; S3, injecting a first soluble liquid capable of dissolving the outer luminal tube and the outer luminal tube coating into the first annular cavity and the second annular cavity of the dissolving device; S4, connecting the dissolving device below the driving rotating machine; S5, lowering the dissolving device to a first preset dissolving position, the first preset dissolving position corresponding to the position of the lowest section to be dissolved; S6, starting the driving rotating machine and turning on the switches of the first nozzle assembly and the second nozzle assembly, the dissolving device rotates to work, and the first nozzle assembly sprays the first soluble solution outward to dissolve the coating of the outer tube of the cavity creation; The second nozzle assembly sprays the first soluble solution inwardly to dissolve the coating of the lumen forming inner tube; S7, after the lowermost section of the outer tube for forming the cavity and the coating of the outer tube for forming the cavity are dissolved, stop driving the rotary machine and turn off the switches of the first nozzle assembly and the second nozzle assembly, and then inject a second soluble liquid that can dissolve the outer tube for forming the cavity and the outer tube for forming the cavity into the first annular cavity and the second annular cavity; The second soluble solution can dissolve the aluminum alloy; S8, after the lowermost section of the cavity-forming outer tube and the cavity-forming outer tube are "cut" and fall into the salt cavern below to be dissolved by brine, the dissolving device is lifted to the second preset dissolving position; the second preset dissolving position is located above the first preset dissolving position and corresponds to the position of the second section below; S9, repeating steps 6 and 7 until all the sections of the outer cavity tube and the inner cavity tube except the uppermost section are cut and fall into the salt cavern below, and then the dissolving device can be taken out.

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