Abandoned mine tunnel gas storage and injection and production method

Abstract

The present invention proposes an abandoned mine tunnel gas storage and an injection and production method. The abandoned mine tunnel gas storage of the present invention comprises: an abandoned mine tunnel; a gas storage sealing layer, the gas storage sealing layer is located in the abandoned mine tunnel, the inner wall surface of the gas storage sealing layer defines a gas storage cavity, and the gas storage cavity is used to store gas; a coating sealing layer, the coating sealing layer is located in the abandoned mine tunnel, the coating sealing layer is located on the outside of the gas storage sealing layer, the coating sealing layer defines a coating cavity, the extension direction of the coating cavity is consistent with the extension direction of the abandoned mine tunnel, the coating cavity covers at least part of the outside of the gas storage cavity, the coating cavity is spaced apart from the gas storage cavity, and the coating cavity is used to introduce the coating gas. The abandoned mine tunnel gas storage according to the present invention can reduce the construction cost of the gas storage and increase the sealing performance.

Description

Technical Field

[0001] The present invention relates to the technical field of abandoned mine tunnel utilization, and in particular to an abandoned mine tunnel gas storage and an injection and production method. Background Art

[0002] To address the numerous challenges in natural gas production, storage, and sales, large-scale gas storage facilities are needed. However, existing technologies for gas storage have long construction cycles and high costs. Furthermore, gas leaks are prone to occur during operation, posing significant safety risks. Summary of the Invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, an embodiment of the present invention provides an abandoned mine tunnel gas storage and an injection and production method.

[0004] The abandoned mine tunnel gas storage in an embodiment of the present invention includes:

[0005] abandoned mine tunnels;

[0006] A gas storage sealing layer, the gas storage sealing layer being located in the abandoned mine tunnel, the inner wall surface of the gas storage sealing layer defining a gas storage cavity, the extension direction of the gas storage cavity being consistent with the extension direction of the abandoned mine tunnel, the gas storage cavity being used to store gas;

[0007] a covering sealing layer, the covering sealing layer being located in the abandoned mine tunnel and outside the gas storage sealing layer, the covering sealing layer defining a covering cavity, the covering cavity extending in a direction consistent with the extending direction of the abandoned mine tunnel, the covering cavity covering at least a portion of the outside of the gas storage cavity, the covering cavity being spaced apart from the gas storage cavity, and the covering cavity being used to introduce covering gas;

[0008] There are multiple covering sealing layers, and the multiple covering sealing layers are arranged in sequence in the inner and outer directions. Two adjacent covering sealing layers define a covering cavity. The outermost covering sealing layer of the two adjacent covering cavities covers at least a portion of the outer side of the innermost covering sealing layer. The innermost covering sealing layer and the gas storage sealing layer define a covering cavity. The outermost covering sealing layer is connected to the wall of the abandoned mine tunnel.

[0009] The gas storage cavity is used to store natural gas, and the covering cavity is used to introduce natural gas;

[0010] The designed operating pressure of the air storage cavity is greater than the designed operating pressure of the covering cavity, and the designed operating pressure of the outer one of the two adjacent covering cavities is less than the designed operating pressure of the inner one.

[0011] In some embodiments, in a cross section of the abandoned mine tunnel, the covering cavity is arranged around the outer periphery of the gas storage cavity, and one of two adjacent covering cavities located on the outer side is arranged around the outer side of the one located on the inner side;

[0012] Alternatively, in the cross section of the abandoned mine tunnel, the covering cavity covers the top and both sides in the horizontal direction of the air storage cavity, and the outer one of the two adjacent covering cavities covers the top and both sides in the horizontal direction of the inner one.

[0013] In some embodiments, in a cross section of the abandoned mine tunnel, the covering cavity is arranged around the outer periphery of the gas storage cavity, and one of two adjacent covering cavities located on the outer side is arranged around the outer side of the one located on the inner side;

[0014] The gas storage sealing layer and the covering sealing layer are made of rigid materials, a support is provided between the gas storage sealing layer and the covering sealing layer, a support is provided between two adjacent covering sealing layers, or the gas storage sealing layer and the covering sealing layer are made of flexible materials.

[0015] In some embodiments, the plurality of covering cavities include a first covering cavity and a second covering cavity, and the air storage cavity, the first covering cavity and the second covering cavity are arranged in sequence from the inside to the outside;

[0016] The design operating pressure of the first covering cavity is two-thirds of the design operating pressure of the gas storage cavity;

[0017] The designed operating pressure of the second covering cavity is one third of the designed operating pressure of the air storage cavity.

[0018] In some embodiments, the abandoned mine tunnel gas storage further includes

[0019] an injection well, the injection well being used to introduce gas into the gas storage chamber, the injection well extending in an up-down direction, the lower opening of the injection well being in communication with the top of the gas storage chamber;

[0020] a production well, the production well being used to discharge the gas in the gas storage chamber, the production well extending in an up-down direction, the lower opening of the production well being in communication with the top of the gas storage chamber;

[0021] A sealing well extends in the up-down direction, a lower opening of the sealing well is communicated with the top of the coating cavity, and each coating cavity has the sealing well matched therewith.

[0022] In some embodiments, pressure monitoring devices are provided in the injection well, the production well, and the sealing well.

[0023] The present invention also proposes a method for injection and production of gas storage using the above-mentioned abandoned mine tunnel, which is characterized by comprising the following steps:

[0024] When natural gas needs to be injected, natural gas is injected into the injection well and the sealing well simultaneously, natural gas is injected into the gas storage cavity through the injection well, and natural gas is injected into the covering cavity through the sealing well, wherein, before the gas pressure in the covering cavity reaches its designed operating pressure, the difference between the gas pressure increase rate in the covering cavity and the gas pressure increase rate in the gas storage cavity is less than or equal to a first preset value;

[0025] When gas production is required, the production well is first opened to discharge the natural gas in the gas storage chamber. During the process of gas pressure decreasing in the gas storage chamber, the sealing well on the covering chamber, in which the difference between the design operating pressure and the gas pressure in the gas storage chamber is less than a second preset value, is opened so that the natural gas in the corresponding covering chamber can be discharged through the corresponding sealing well. The difference between the pressure reduction rate of the natural gas in the covering chamber when the natural gas is discharged and the pressure reduction rate of the natural gas in the gas storage chamber is less than or equal to a third preset value.

[0026] In some embodiments, there are multiple covering cavities, including a first covering cavity and a second covering cavity, and the air storage cavity, the first covering cavity and the second covering cavity are arranged in sequence from the inside to the outside;

[0027] The design operating pressure of the first covering cavity is two-thirds of the design operating pressure of the gas storage cavity;

[0028] The design operating pressure of the second covering cavity is one third of the design operating pressure of the gas storage cavity;

[0029] When natural gas needs to be injected, when the gas pressure in the second covering cavity reaches one-third of the design operating pressure of the gas storage cavity, the injection of natural gas into the second covering cavity is stopped; when the gas pressure in the first covering cavity reaches two-thirds of the design operating pressure of the gas storage cavity, the injection of natural gas into the first covering cavity is stopped; and when the gas pressure in the gas storage cavity reaches the design operating pressure of the gas storage cavity, the injection of natural gas into the gas storage cavity is stopped;

[0030] When gas production is required, the production well is first opened to discharge the natural gas in the gas storage chamber. During the process of gas pressure decreasing in the gas storage chamber, when the gas pressure in the gas storage chamber drops to two-thirds of its designed operating pressure, the sealing well on the first covering chamber is opened to discharge the natural gas. When the gas pressure in the gas storage chamber drops to one-third of its designed operating pressure, the sealing well on the second covering chamber is opened to discharge the natural gas. The difference between the pressure reduction rate of the natural gas in each of the first covering chamber and the second covering chamber and the pressure reduction rate of the natural gas in the gas storage chamber is less than or equal to the third preset value.

[0031] The beneficial effects of the present invention are as follows: the abandoned mine tunnel gas storage reservoir according to the embodiments of the present invention adopts a multi-stage pressure seal structure, converting the original single seal layer's strong load into a multi-stage weak load, reducing the mechanical strength and construction quality requirements of the seal layer during the reservoir construction process, and effectively reducing the gas storage construction cost. It also expands the site selection range of abandoned coal mine tunnels, improving the regional distribution of abandoned mine tunnel gas storage reservoirs of different types and improving the utilization rate of the tunnels. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of an abandoned mine tunnel gas storage according to an embodiment of the present invention.

[0033] Figure 2 Schematic diagram of a cross section of an abandoned mine tunnel gas storage according to an embodiment of the present invention.

[0034] Reference numerals:

[0035] 1. Abandoned mine tunnel, 11. Injection well, 12. Production well, 13. Sealing well;

[0036] 2. Gas storage sealing layer, 21. Gas storage cavity;

[0037] 3. Coating sealing layer, 31. Coating cavity, 32. First coating cavity, 33. Second coating cavity. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0039] The following describes the abandoned mine tunnel gas storage according to an embodiment of the present invention with reference to the accompanying drawings. Figures 1 to 2 As shown, the abandoned mine tunnel gas storage according to an embodiment of the present invention includes an abandoned mine tunnel 1, a gas storage sealing layer 2 and a coating sealing layer 3.

[0040] The gas storage sealing layer 2 is located within the abandoned mine tunnel 1. The inner wall of the gas storage sealing layer 2 defines a gas storage cavity 21. The gas storage cavity 21 extends in the same direction as the abandoned mine tunnel 1. The gas storage cavity 21 is used to store gas. For example, the abandoned mine tunnel 1 is a straight tunnel section.

[0041] The coating sealing layer 3 is located within the abandoned mine tunnel 1 and outside the gas storage sealing layer 2. The coating sealing layer 3 defines a coating cavity 31. The coating cavity 31 extends in the same direction as the abandoned mine tunnel 1. The coating cavity 31 covers at least a portion of the outside of the gas storage cavity 21. The coating cavity 31 is spaced apart from the gas storage cavity 21 and is used to introduce the coating gas.

[0042] The abandoned mine tunnel gas storage facility according to an embodiment of the present invention can utilize an abandoned mine tunnel 1 as a gas storage facility, thereby reducing the cost and difficulty of its construction. Abandoned mine tunnel 1 preferably comprises a tunnel section with a large tunnel cross-section and good surrounding rock integrity. A gas storage sealing layer 2 is provided within the abandoned mine tunnel 1 to form a gas storage cavity 21 capable of storing gas. Furthermore, a coating sealing layer 3 is provided on the outside of the gas storage sealing layer 2. The coating sealing layer 3 forms a coating cavity 31 that covers at least a portion of the outside of the gas storage cavity 21. The gas storage sealing layer 2 and the coating cavity 31 protect the gas storage sealing layer 2 (gas storage cavity 21), thereby improving the sealing performance of the abandoned mine tunnel gas storage facility according to an embodiment of the present invention.

[0043] like Figure 1 and Figure 2 As shown, in some embodiments, there are multiple covering sealing layers 3, and the multiple covering sealing layers 3 are arranged in sequence in the inner and outer directions.

[0044] The outermost covering sealing layer 3 is connected to the wall of the abandoned mine tunnel 1 , that is, the outermost covering sealing layer 3 is fixed on the wall of the abandoned mine tunnel 1 so as to make full use of the space in the abandoned mine tunnel 1 .

[0045] The outermost of the two adjacent covering cavities 31 covers at least a portion of the outermost of the innermost, and the two adjacent covering sealing layers 3 define a covering cavity 31. That is, the inner wall surface of the outermost of the two adjacent covering cavities 31 and the outer wall surface of the innermost define a covering cavity 31.

[0046] The innermost covering sealing layer 3 and the gas storage sealing layer 2 define a covering cavity 31. That is, the inner wall surface of the innermost covering sealing layer 3 and the outer wall surface of the gas storage sealing layer 2 define a covering cavity 31.

[0047] like Figure 2As shown, in some embodiments, in the cross-section of the abandoned mine tunnel 1, the covering cavity 31 is arranged around the outer periphery of the gas storage cavity 21, and the outer one of the two adjacent covering cavities 31 is arranged around the outer side of the inner one. Specifically, the gas storage sealing layer 2, the covering sealing layer 3, the covering cavity 31, and the gas storage cavity 21 form an annular structure that adapts to the shape of the tunnel in the circumferential direction. The covering cavity 31 is arranged around the outer periphery of the gas storage cavity 21, thereby protecting the gas storage cavity 21 without blind spots. There can be multiple covering cavities 31, and the multiple covering cavities 31 are arranged sequentially in the inner and outer directions, so that the covering cavity 31 on the outer side can protect the covering cavity 31 on the inner side.

[0048] In some embodiments, in the cross section of the abandoned mine tunnel 1, the covering cavity 31 covers the top and both sides of the gas storage cavity 21 in the horizontal direction, and the outer one of the two adjacent covering cavities 31 covers the top and both sides of the inner one in the horizontal direction. Specifically, in the cross section of the abandoned mine tunnel 1, the covering cavity 31 includes an arcuate cavity located at the top of the gas storage cavity 21 and side cavities located on both sides of the gas storage cavity 21 in the width direction of the abandoned mine tunnel 1, so that in the cross section of the abandoned mine tunnel 1, the covering cavity 31 covers the top and both sides of the gas storage cavity 21 in the horizontal direction. There can be multiple covering cavities 31, and the multiple covering cavities 31 are arranged in sequence in the inner and outer directions, so that the covering cavity 31 located on the outer side can protect the covering cavity 31 located on the inner side.

[0049] In some embodiments, the gas storage cavity 21 and the covering cavity 31 are sealed by seals at both ends of the abandoned mine tunnel 1 in the longitudinal direction. Alternatively, a portion of the gas storage sealing layer 2 is located at both ends of the gas storage cavity 21 in the longitudinal direction, thereby sealing the openings at both ends of the gas storage cavity 21 in the longitudinal direction. A portion of the covering sealing layer 3 is located at both ends of the covering cavity 31 in the longitudinal direction, thereby sealing the openings at both ends of the covering cavity 31 in the longitudinal direction.

[0050] In some embodiments, in the cross section of the abandoned mine tunnel 1 , the covering cavity 31 is arranged around the outer periphery of the gas storage cavity 21 , and the outer one of the two adjacent covering cavities 31 is arranged around the outer side of the inner one.

[0051] The gas storage sealing layer 2 and the covering sealing layer 3 are made of rigid materials, a support is provided between the gas storage sealing layer 2 and the covering sealing layer 3, and a support is provided between two adjacent covering sealing layers 3. Alternatively, the gas storage sealing layer 2 and the covering sealing layer 3 are made of flexible materials.

[0052] That is, when the encapsulation cavity 31 is an annular structure and the gas storage sealing layer 2 and the encapsulation sealing layer 3 are made of a rigid material, a support member is provided between the gas storage sealing layer 2 and the encapsulation sealing layer 3, and a support member is provided between two adjacent encapsulation sealing layers 3, so that an annular encapsulation cavity 31 can be formed between the gas storage sealing layer 2 and the encapsulation sealing layer 3, and an annular encapsulation cavity 31 can be formed between two adjacent encapsulation sealing layers 3. For example, the gas storage sealing layer 2 and the encapsulation sealing layer 3 are made of a rigid material, and each of the gas storage sealing layer 2 and the encapsulation sealing layer 3 includes a multi-layer steel lining, which solves the problem of the thickness and weight of a single welded steel plate during the steel lining construction process.

[0053] Alternatively, the enclosing cavity 31 may be annular in structure, and the gas storage sealing layer 2 and the enclosing sealing layer 3 may be made of a flexible material so that after being filled with gas, an annular enclosing cavity 31 may be formed. The mechanical strength (compressive strength) of the gas storage sealing layer 2 and the enclosing sealing layer 3 should be greater than one-third of their designed operating pressure.

[0054] The system utilizes a multi-layered sealing system, consisting of a gas storage sealing layer 2 and multiple encapsulating sealing layers 3. The multi-layered sealing layer utilizes flexible, pressure-resistant sealing materials or a single welded steel lining. This design is large, lightweight, and easy to transport. Furthermore, the system's construction process effectively reduces welding work, minimizing on-site construction workload and shortening the construction cycle. Furthermore, the reduced number of welds reduces the probability of weld defects and improves system reliability.

[0055] like Figure 1 and Figure 2 As shown, the multiple covering cavities 31 include a first covering cavity 32 and a second covering cavity 33. The air storage cavity 21, the first covering cavity 32, and the second covering cavity 33 are arranged sequentially from the inside to the outside. In other words, there are two covering cavities 31. The two covering cavities 31 (the first covering cavity 32 and the second covering cavity 33) can improve the sealing performance of the air storage cavity 21.

[0056] like Figure 1 As shown, the abandoned mine tunnel gas storage also includes an injection well 11, a production well 12 and a sealing well 13.

[0057] The injection well 11 is used to introduce gas into the gas storage chamber 21. The injection well 11 extends in the vertical direction, and the lower end of the injection well 11 is connected to the top of the gas storage chamber 21. Specifically, the injection well 11 is opened in the rock mass above the abandoned mine tunnel 1 and is connected to the ground. The lower end of the injection well 11 extends into the gas storage chamber 21 to inject natural gas into the gas storage chamber 21.

[0058] Production well 12 is used to discharge gas from gas storage chamber 21. Production well 12 extends in the vertical direction, with its lower opening communicating with the top of gas storage chamber 21. Specifically, production well 12 is located in the rock mass above abandoned mine tunnel 1 and communicates with the ground. The lower opening of production well 12 extends into gas storage chamber 21, allowing natural gas in gas storage chamber 21 to be discharged from production well 12.

[0059] The sealing well 13 extends vertically, with its lower opening communicating with the top of the enclosure cavity 31. Each enclosure cavity 31 has a corresponding sealing well 13. Specifically, the sealing well 13 is located in the rock mass above the abandoned mine tunnel 1 and communicates with the ground. The lower opening of the sealing well 13 extends into the corresponding enclosure cavity 31, allowing natural gas to flow into or out of the enclosure cavity 31 through the sealing well 13.

[0060] In some embodiments, the gas storage chamber 21 is used to store natural gas, and the covering chamber 31 is used to introduce natural gas. The design operating pressure of the gas storage chamber 21 is greater than the design operating pressure of the covering chamber 31, and the design operating pressure of the outermost of two adjacent covering chambers 31 is less than the design operating pressure of the innermost.

[0061] In some embodiments, the design operating pressure of the first covering cavity 32 is two-thirds of the design operating pressure of the air storage cavity 21 , and the design operating pressure of the second covering cavity 33 is one-third of the design operating pressure of the air storage cavity 21 .

[0062] In some embodiments, pressure monitoring devices are provided in the injection well 11 , the production well 12 , and the sealing well 13 .

[0063] The leakage of the gas storage chamber 21 can be monitored based on the pressure monitoring devices in the injection well 11 and the production well 12. For example, when the pressure monitoring devices in the injection well 11 and the production well 12 detect that the pressure in the gas storage chamber 21 decreases, it can be determined that the natural gas in the gas storage chamber 21 is leaking.

[0064] The pressure monitoring device in the sealing well 13 monitors leakage from the covering cavity 31. For example, if the pressure monitoring device in the sealing well 13 detects a decrease in the pressure in the covering cavity 31, it can be determined that natural gas is leaking from the covering cavity 31. If the pressure monitoring device in the sealing well 13 detects an increase in the pressure in the covering cavity 31, it can be determined that natural gas is leaking from a cavity adjacent to and located inside the covering cavity 31 (the covering cavity 31 or the gas storage cavity 21).

[0065] The present invention also proposes an injection and production method using an abandoned mine tunnel gas storage according to an embodiment of the present invention. The injection and production method using an abandoned mine tunnel gas storage according to an embodiment of the present invention comprises the following steps:

[0066] When natural gas needs to be injected, natural gas is injected into the injection well 11 and the sealing well 13 at the same time, natural gas is injected into the gas storage chamber 21 through the injection well 11, and natural gas is injected into the coating chamber 31 through the sealing well 13. Before the gas pressure in the coating chamber 31 reaches its designed operating pressure, the difference between the gas pressure growth rate in the coating chamber 31 and the gas pressure growth rate in the gas storage chamber 21 is less than or equal to a first preset value.

[0067] Specifically, the value of the first preset value is close to 0, and the difference between the gas pressure growth rate in the coating cavity 31 and the gas pressure growth rate in the gas storage cavity 21 is less than or equal to the first preset value. That is, when natural gas needs to be injected, gas is injected into the gas storage cavity 21 and the coating cavity 31 simultaneously. The gas injection process adjusts the gas injection flow rate to control the gas pressure growth rate in the coating cavity 31 to be similar to the gas pressure growth rate in the gas storage cavity 21, so that the pressures in the gas storage cavity 21 and the coating cavity 31 during the gas injection process are similar until the gas pressure in the coating cavity 31 reaches its designed operating pressure.

[0068] When gas production is required, the production well 12 is first opened to discharge the natural gas in the gas storage chamber 21. As the gas pressure in the gas storage chamber 21 decreases, the sealing wells 13 on the sheathing chamber 31 where the difference between the designed operating pressure and the gas pressure in the gas storage chamber 21 is less than a second preset value are opened to discharge the natural gas in the corresponding sheathing chamber 31 through the corresponding sealing well 13. The difference between the pressure drop rate of the natural gas in the sheathing chamber 31 during the discharge and the pressure drop rate of the natural gas in the gas storage chamber 21 is less than or equal to a third preset value.

[0069] Specifically, the second preset value is close to 0, and the third preset value is close to 0. When gas extraction is required, the natural gas in the gas storage chamber 21 is first discharged. During the process of reducing the pressure in the gas storage chamber 21, if the pressure in the sheath chamber 31 (designed operating pressure) is close to the pressure of the gas storage chamber 21 after the pressure reduction (the difference is less than the second preset value), the sealing well 13 on the sheath chamber 31 is opened to exhaust gas. The pressure reduction rate of the natural gas in the sheath chamber 31 during the gas extraction process is also close to the pressure reduction rate of the natural gas in the gas storage chamber 21 (the difference is less than or equal to the third preset value), thereby ensuring that the pressures in the gas storage chamber 21 and the sheath chamber 31 are similar during the gas extraction process.

[0070] In some embodiments, there are multiple covering cavities 31, including a first covering cavity 32 and a second covering cavity 33. The air storage cavity 21, the first covering cavity 32, and the second covering cavity 33 are arranged in order from the inside to the outside. The design operating pressure of the first covering cavity 32 is two-thirds of the design operating pressure of the air storage cavity 21, and the design operating pressure of the second covering cavity 33 is one-third of the design operating pressure of the air storage cavity 21.

[0071] When natural gas needs to be injected, the injection of natural gas into the second covering cavity 33 is stopped when the gas pressure in the second covering cavity 33 reaches one-third of the design operating pressure of the gas storage cavity 21; the injection of natural gas into the first covering cavity 32 is stopped when the gas pressure in the first covering cavity 32 reaches two-thirds of the design operating pressure of the gas storage cavity 21; and the injection of natural gas into the gas storage cavity 21 is stopped when the gas pressure in the gas storage cavity 21 reaches the design operating pressure of the gas storage cavity 21.

[0072] Specifically, the sealing well 13 on the second containment chamber 33, the sealing well 13 on the first containment chamber 32, and the injection well 11 on the gas storage chamber 21 are sequentially opened, and gas is injected simultaneously. This ensures that the gas pressure within the gas storage chamber 21, the first containment chamber 32, and the second containment chamber 33 increases at a rate similar to that of natural gas pressure. Gas injection is terminated when the second containment chamber 33 reaches its designed operating pressure, when the first containment chamber 32 reaches its designed operating pressure, and when the gas storage chamber 21 reaches its designed operating pressure. The entire gas injection process is completed.

[0073] When gas production is required, the production well 12 is first opened to discharge the natural gas within the gas storage chamber 21. As the gas pressure within the gas storage chamber 21 decreases, when the gas pressure within the gas storage chamber 21 drops to two-thirds of its designed operating pressure, the sealing well 13 on the first covering chamber 32 is opened to discharge the natural gas. When the gas pressure within the gas storage chamber 21 drops to one-third of its designed operating pressure, the sealing well 13 on the second covering chamber 33 is opened to discharge the natural gas. The difference between the pressure reduction rate of the natural gas within each of the first covering chamber 32 and the second covering chamber 33 and the pressure reduction rate of the natural gas within the gas storage chamber 21 is less than or equal to a third preset value.

[0074] Specifically, when gas extraction is required, the natural gas in the gas storage chamber 21 is first discharged. As the pressure in the gas storage chamber 21 decreases, when the pressure in the gas storage chamber 21 approaches the pressure in the first enclosure chamber 32 (designed operating pressure), the natural gas in the first enclosure chamber 32 is exhausted. When the pressure in the gas storage chamber 21 approaches the pressure in the second enclosure chamber 33 (designed operating pressure), the natural gas in the second enclosure chamber 33 is exhausted. Furthermore, the pressure reduction rates of the natural gas in the first enclosure chamber 32 and the second enclosure chamber 33 are similar to the pressure reduction rate of the natural gas in the gas storage chamber 21 (the difference is less than or equal to a third preset value), thereby ensuring that the pressures in the gas storage chamber 21, the first enclosure chamber 32, and the second enclosure chamber 33 are similar during gas extraction.

[0075] According to the abandoned mine tunnel gas storage reservoir of the embodiment of the present invention, a gas storage sealing layer 2 and a coating sealing layer 3 are set in the abandoned mine tunnel 1, thereby forming a multi-step pressure sealing structure, which converts the original single sealing layer strong load into a multi-step weak load, reduces the mechanical strength and construction quality requirements of the sealing layer material during the reservoir construction process, and effectively reduces the construction cost of the gas storage reservoir. It can realize the redundant function of gas leakage safety during the operation of the gas storage reservoir, avoid the leakage risk caused by damage to the single sealing layer, and improve the safety of the gas storage reservoir system. Compared with the reservoir construction method in the related art, it has better advantages in sealing and safety, reduces the requirements of the gas storage reservoir on the geological structure and surrounding rock permeability of the mining area, expands the site selection range of abandoned coal mine tunnels, and improves the regional distribution of different types of abandoned mine tunnel gas storage reservoirs and the utilization rate of the tunnels.

[0076] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying 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 limiting the present invention.

[0077] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0078] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0079] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0080] In the present invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification, as well as features of different embodiments or examples, unless they are mutually inconsistent.

[0081] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. An abandoned mine tunnel gas storage, characterized in that: include: abandoned mine tunnels; A gas storage sealing layer, the gas storage sealing layer being located in the abandoned mine tunnel, the inner wall surface of the gas storage sealing layer defining a gas storage cavity, the extension direction of the gas storage cavity being consistent with the extension direction of the abandoned mine tunnel, the gas storage cavity being used to store gas; a covering sealing layer, the covering sealing layer being located in the abandoned mine tunnel and outside the gas storage sealing layer, the covering sealing layer defining a covering cavity, the covering cavity extending in a direction consistent with the extending direction of the abandoned mine tunnel, the covering cavity covering at least a portion of the outside of the gas storage cavity, the covering cavity being spaced apart from the gas storage cavity, and the covering cavity being used to introduce covering gas; There are multiple covering sealing layers, and the multiple covering sealing layers are arranged in sequence in the inner and outer directions. Two adjacent covering sealing layers define a covering cavity. The outermost covering sealing layer of the two adjacent covering cavities covers at least a portion of the outer side of the innermost covering sealing layer. The innermost covering sealing layer and the gas storage sealing layer define a covering cavity. The outermost covering sealing layer is connected to the wall of the abandoned mine tunnel. The gas storage cavity is used to store natural gas, and the covering cavity is used to introduce natural gas; The designed operating pressure of the air storage cavity is greater than the designed operating pressure of the covering cavity, and the designed operating pressure of the outer one of the two adjacent covering cavities is less than the designed operating pressure of the inner one.

2. The abandoned mine tunnel gas storage according to claim 1, characterized in that: In the cross section of the abandoned mine tunnel, the covering cavity is arranged in a ring on the outer peripheral side of the gas storage cavity, and one of the two adjacent covering cavities located on the outer side is arranged in a ring on the outer side of the one located on the inner side; Alternatively, in the cross section of the abandoned mine tunnel, the covering cavity covers the top and both sides in the horizontal direction of the air storage cavity, and the outer one of the two adjacent covering cavities covers the top and both sides in the horizontal direction of the inner one.

3. The abandoned mine tunnel gas storage according to claim 2, characterized in that: In the cross section of the abandoned mine tunnel, the covering cavity is arranged in a ring on the outer peripheral side of the gas storage cavity, and one of the two adjacent covering cavities located on the outer side is arranged in a ring on the outer side of the one located on the inner side; The gas storage sealing layer and the covering sealing layer are made of rigid materials, a support is provided between the gas storage sealing layer and the covering sealing layer, a support is provided between two adjacent covering sealing layers, or the gas storage sealing layer and the covering sealing layer are made of flexible materials.

4. The abandoned mine tunnel gas storage according to claim 1, characterized in that: The plurality of covering cavities include a first covering cavity and a second covering cavity, and the air storage cavity, the first covering cavity and the second covering cavity are arranged in sequence from the inside to the outside; The design operating pressure of the first covering cavity is two-thirds of the design operating pressure of the gas storage cavity; The designed operating pressure of the second covering cavity is one third of the designed operating pressure of the air storage cavity.

5. The abandoned mine tunnel gas storage according to any one of claims 1 to 4, characterized in that: The abandoned mine tunnel gas storage also includes an injection well, the injection well being used to introduce gas into the gas storage chamber, the injection well extending in an up-down direction, the lower opening of the injection well being in communication with the top of the gas storage chamber; a production well, the production well being used to discharge the gas in the gas storage chamber, the production well extending in an up-down direction, the lower opening of the production well being in communication with the top of the gas storage chamber; A sealing well extends in the up-down direction, a lower opening of the sealing well is communicated with the top of the coating cavity, and each coating cavity has the sealing well matched therewith.

6. The abandoned mine tunnel gas storage according to claim 5, characterized in that: The injection well, the production well and the sealing well are all provided with pressure monitoring devices.

7. A method for injection and production of gas storage in abandoned mine tunnels using the gas storage reservoir according to claim 5, characterized in that: The following steps are involved: When natural gas needs to be injected, natural gas is injected into the injection well and the sealing well simultaneously, natural gas is injected into the gas storage cavity through the injection well, and natural gas is injected into the covering cavity through the sealing well, wherein, before the gas pressure in the covering cavity reaches its designed operating pressure, the difference between the gas pressure increase rate in the covering cavity and the gas pressure increase rate in the gas storage cavity is less than or equal to a first preset value; When gas production is required, the production well is first opened to discharge the natural gas in the gas storage chamber. During the process of gas pressure decreasing in the gas storage chamber, the sealing well on the covering chamber, in which the difference between the design operating pressure and the gas pressure in the gas storage chamber is less than a second preset value, is opened so that the natural gas in the corresponding covering chamber can be discharged through the corresponding sealing well. The difference between the pressure reduction rate of the natural gas in the covering chamber when the natural gas is discharged and the pressure reduction rate of the natural gas in the gas storage chamber is less than or equal to a third preset value.

8. The abandoned mine tunnel gas storage injection and production method according to claim 7, characterized in that: There are multiple covering cavities, including a first covering cavity and a second covering cavity, and the air storage cavity, the first covering cavity and the second covering cavity are arranged in sequence from the inside to the outside; The design operating pressure of the first covering cavity is two-thirds of the design operating pressure of the gas storage cavity; The design operating pressure of the second covering cavity is one third of the design operating pressure of the gas storage cavity; When natural gas needs to be injected, when the gas pressure in the second covering cavity reaches one-third of the design operating pressure of the gas storage cavity, the injection of natural gas into the second covering cavity is stopped; when the gas pressure in the first covering cavity reaches two-thirds of the design operating pressure of the gas storage cavity, the injection of natural gas into the first covering cavity is stopped; and when the gas pressure in the gas storage cavity reaches the design operating pressure of the gas storage cavity, the injection of natural gas into the gas storage cavity is stopped; When gas production is required, the production well is first opened to discharge the natural gas in the gas storage chamber. During the process of gas pressure decreasing in the gas storage chamber, when the gas pressure in the gas storage chamber drops to two-thirds of its designed operating pressure, the sealing well on the first covering chamber is opened to discharge the natural gas. When the gas pressure in the gas storage chamber drops to one-third of its designed operating pressure, the sealing well on the second covering chamber is opened to discharge the natural gas. The difference between the pressure reduction rate of the natural gas in each of the first covering chamber and the second covering chamber and the pressure reduction rate of the natural gas in the gas storage chamber is less than or equal to the third preset value.

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