Waste mine laneway gas storage and injection-production method

Abstract

The invention provides an abandoned mine laneway gas storage and an injection-production method. The abandoned mine laneway gas storage comprises an abandoned mine laneway; the gas storage sealing layer is located in the abandoned mine laneway, a gas storage cavity is defined by the inner wall face of the gas storage sealing layer, and the gas storage cavity is used for storing gas; the wrapping sealing layers are located in the abandoned mine laneway, the wrapping sealing layers are located on the outer side of the gas storage sealing layer, wrapping cavities are defined by the wrapping sealing layers, the extending direction of the wrapping cavities is consistent with the extending direction of the abandoned mine laneway, the wrapping cavities wrap at least part of the outer side of the gas storage cavity, the wrapping cavities and the gas storage cavity are arranged in a spaced mode, and the wrapping sealing layers are located in the abandoned mine laneway and located on the outer side of the gas storage cavity. And the coating cavity is used for introducing coating gas. According to the abandoned mine laneway gas storage, the construction cost of the gas storage can be reduced, and the sealing performance can be improved.

Description

Technical Field

[0001] The 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] In order to solve many problems in the production, storage and sales of natural gas, it is necessary to build large-scale gas storage facilities for storage. In the relevant technologies, the construction period of gas storage facilities is long and the construction cost is high. After completion, gas storage facilities are prone to gas leakage during operation, which poses a great safety risk. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least 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 comprises:

[0005] Abandoned mine tunnels;

[0006] 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, the extension direction of the gas storage cavity is consistent with the extension direction of the abandoned mine tunnel, and the gas storage cavity is used to store gas;

[0007] At least one 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 pass the coating gas.

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

[0009] In some embodiments, on the cross section of the abandoned mine tunnel, the covering cavity is arranged around the outer peripheral side of the gas storage cavity, and one of the two adjacent covering cavities located on the outer side is arranged around the outer side of the one located on the inner side;

[0010] 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.

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

[0012] 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.

[0013] In some embodiments, the gas storage cavity is used to store natural gas, and the covering cavity is used to introduce natural gas;

[0014] 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.

[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 inside to 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 design operating pressure of the second covering cavity is one third of the design 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 is used to introduce gas into the gas storage chamber, the injection well extends in an up-down direction, and a lower opening of the injection well is connected to the top of the gas storage chamber;

[0020] A production well, the production well is used to discharge the gas in the gas storage cavity, the production well extends in the up-down direction, and the lower opening of the production well is connected to the top of the gas storage cavity;

[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 of the coating cavities has the sealing well matched therewith.

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

[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 at the same time, natural gas is injected into the gas storage cavity through the injection well, and natural gas is injected into the coating cavity through the sealing well, wherein before the gas pressure in the coating cavity reaches its designed operating pressure, the difference between the gas pressure growth rate in the coating cavity and the gas pressure growth 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 whose difference between the designed 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, wherein the difference between the pressure reduction rate of the natural gas in the covering chamber for discharging the natural gas 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, the multiple 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 inside to 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; 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 needed, first open the production well 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 decreases to two-thirds of its designed operating pressure, open the sealing well on the first covering chamber to discharge the natural gas. When the gas pressure in the gas storage chamber decreases to one-third of its designed operating pressure, open the sealing well on the second covering chamber to discharge the natural gas, wherein 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 according to the embodiment of the present invention adopts a multi-step pressure sealing structure, converting the original single sealing layer strong load into a multi-step weak load, reducing the mechanical strength and construction quality requirements of the sealing layer material during the construction process, and effectively reducing the construction cost of the gas storage. The site selection range of abandoned coal mine tunnels is expanded, and the regional distribution and tunnel utilization rate of different types of abandoned mine tunnel gas storage construction are improved. 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 tunnels, 11. Injection wells, 12. Production wells, 13. Sealed wells;

[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] 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 abandoned mine tunnel gas storage in an embodiment of the present invention is described below with reference to the accompanying drawings. Figure 1 to Figure 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 at least one coating sealing layer 3.

[0040] The gas storage sealing layer 2 is located in the abandoned mine tunnel 1, and the inner wall surface of the gas storage sealing layer 2 defines a gas storage cavity 21. The extension direction of the gas storage cavity 21 is consistent with the extension direction of 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 in the abandoned mine tunnel 1, and the coating sealing layer 3 is located on the outside of the gas storage sealing layer 2. The coating sealing layer 3 defines a coating cavity 31. The extension direction of the coating cavity 31 is consistent with the extension direction of the abandoned mine tunnel 1. The coating cavity 31 covers at least part of the outside of the gas storage cavity 21. The coating cavity 31 is spaced apart from the gas storage cavity 21, and the coating cavity 31 is used to pass the coating gas.

[0042] The abandoned mine tunnel gas storage according to the embodiment of the present invention can use the abandoned mine tunnel 1 as a gas storage so as to reduce the construction cost and difficulty of the gas storage. The abandoned mine tunnel 1 preferably selects a tunnel section with a large tunnel section and good surrounding rock integrity. A gas storage sealing layer 2 is arranged in the abandoned mine tunnel 1 to form a gas storage cavity 21 that can store gas. And a coating sealing layer 3 is arranged on the outside of the gas storage sealing layer 2, and the coating sealing layer 3 can form a coating cavity 31 that is coated on the outside of at least part of the gas storage cavity 21, so that the gas storage sealing layer 2 and the coating cavity 31 can be used to protect the gas storage sealing layer 2 (gas storage cavity 21), thereby improving the sealing of the abandoned mine tunnel gas storage according to the 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 surface of the abandoned mine tunnel 1 , that is, the outermost covering sealing layer 3 is fixed on the wall surface of the abandoned mine tunnel 1 so as to make full use of the space in the abandoned mine tunnel 1 .

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

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

[0047] like Figure 2As shown, in some embodiments, on the cross section of the abandoned mine tunnel 1, the covering cavity 31 is arranged on the outer peripheral side of the gas storage cavity 21, and one of the two adjacent covering cavities 31 located on the outer side is arranged on the outer side of the one located on the inner side. Specifically, the gas storage sealing layer 2, the covering sealing layer 3, the covering cavity 31, and the gas storage cavity 21 are annular structures that are adapted to the shape of the tunnel in the circumferential direction, and the covering cavity 31 is arranged on the outer peripheral side of the gas storage cavity 21, thereby protecting the gas storage cavity 21 without dead angles. And there can be multiple covering cavities 31, and 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.

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

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

[0050] In some embodiments, in the cross section of the abandoned mine tunnel 1, the covering cavity 31 is arranged on the outer peripheral side of the gas storage cavity 21, and the outer one of the two adjacent covering cavities 31 is arranged on 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 covering cavity 31 is an annular structure and 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, so that an annular covering cavity 31 can be formed between the gas storage sealing layer 2 and the covering sealing layer 3, and an annular covering cavity 31 can be formed between two adjacent covering sealing layers 3. For example, the gas storage sealing layer 2 and the covering sealing layer 3 are made of rigid materials, and each of the gas storage sealing layer 2 and the covering sealing layer 3 includes a multi-layer steel lining, which solves the problem of the thickness of a single welded steel plate during the steel lining construction process.

[0053] Alternatively, the encapsulation cavity 31 is an annular structure and the gas storage sealing layer 2 and the encapsulation sealing layer 3 are made of flexible materials so that after filling with gas, an annular encapsulation cavity 31 can be formed. The mechanical strength (pressure resistance) of the gas storage sealing layer 2 and the encapsulation sealing layer 3 should be greater than one third of their designed operating pressure.

[0054] A multi-layer sealing method is adopted to form a gas storage sealing layer 2 and multiple covering sealing layers 3. The multi-layer sealing layer uses flexible pressure-resistant sealing materials or a single welded steel lining, which has a large area and light weight, is easy to carry, and the construction process can effectively reduce welding construction, reduce on-site construction work, and shorten the construction period. In addition, the reduction in the number of welds can reduce the probability of weld defects and improve the reliability of the system.

[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, and the gas storage cavity 21, the first covering cavity 32 and the second covering cavity 33 are arranged in sequence from the inside to the outside. That is, there are two covering cavities 31, and the two covering cavities 31 (the first covering cavity 32 and the second covering cavity 33) can improve the sealing performance of the gas 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 up-down 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 so as to inject natural gas into the gas storage chamber 21.

[0058] The production well 12 is used to discharge the gas in the gas storage chamber 21. The production well 12 extends in the up-down direction, and the lower opening of the production well 12 is connected to the top of the gas storage chamber 21. Specifically, the production well 12 is opened in the rock mass above the abandoned mine tunnel 1 and is connected to the ground. The lower opening of the production well 12 extends into the gas storage chamber 21, so that the natural gas in the gas storage chamber 21 can be discharged from the production well 12.

[0059] The sealing well 13 extends in the up-down direction, and the lower opening of the sealing well 13 is connected to the top of the covering cavity 31, and each covering cavity 31 has a sealing well 13 matched therewith. Specifically, the sealing well 13 is opened in the rock mass above the abandoned mine tunnel 1 and is connected to the ground, and the lower opening of the sealing well 13 extends into the corresponding covering cavity 31, so that the covering cavity 31 can pass in or discharge natural gas 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 outer one of the two adjacent covering chambers 31 is less than the design operating pressure of the inner one.

[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 . 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 by 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 of the sealing well 13 monitors the leakage of the covering cavity 31. For example, when the pressure monitoring device in the sealing well 13 detects that the pressure in the covering cavity 31 decreases, it can be determined that the natural gas in the covering cavity 31 leaks. When the pressure monitoring device in the sealing well 13 detects that the pressure in the covering cavity 31 increases, it can be determined that the natural gas in the cavity (covering cavity 31 or gas storage cavity 21) adjacent to and located inside the covering cavity 31 leaks into it.

[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 of the 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, wherein, 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 21 simultaneously, and the gas injection process controls the gas pressure growth rate in the coating cavity 31 and the gas pressure growth rate in the gas storage cavity 21 to be similar by adjusting the gas injection flow rate, so that the pressures in the gas storage cavity 21 and the coating cavity 21 during the gas injection process are similar until the gas pressure in the coating cavity 21 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. During the process of gas pressure reduction in the gas storage chamber 21, the sealing well 13 on the covering chamber 31 whose difference between the design operating pressure and the gas pressure in the gas storage chamber 21 is less than the second preset value is opened, so as to discharge the natural gas in the corresponding covering chamber 31 through the corresponding sealing well 13. The difference between the pressure reduction rate of the natural gas in the covering chamber 31 from which the natural gas is discharged and the pressure reduction rate of the natural gas in the gas storage chamber 21 is less than or equal to the third preset value.

[0069] Specifically, the value of the second preset value is close to 0, and the value of the third preset value is close to 0. When gas extraction is required, the natural gas in the gas storage chamber 21 is discharged first. In 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 is reduced (the difference is less than the second preset value), the sealing well 13 on the sheath chamber 31 is opened to exhaust gas. And the pressure reduction rate of the natural gas in the sheath chamber 31 that discharges the natural gas is 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), so that the pressures of the gas storage chamber 21 and the sheath chamber 21 during the gas extraction process are similar.

[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 sequentially arranged 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, 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 second covering cavity 33 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, the injection of natural gas into the first covering cavity 32 is stopped; when the gas pressure in the gas storage cavity 21 reaches the design operating pressure of the gas storage cavity 21, the injection of natural gas into the gas storage cavity 21 is stopped.

[0072] Specifically, the sealing well 13 on the second covering cavity 33, the sealing well 13 on the first covering cavity 32 and the injection well 11 on the gas storage cavity 21 are opened in sequence, and gas is injected synchronously, so that the gas pressure growth rate in the gas storage cavity 21, the first covering cavity 32 and the second covering cavity 33 is close to the natural gas pressure. When the second covering cavity 33 reaches its designed operating pressure, the gas injection is stopped, when the first covering cavity 32 reaches its designed operating pressure, the gas injection is stopped, and when the gas storage cavity 21 reaches its designed operating pressure, the gas injection is stopped, and the whole gas injection process is completed.

[0073] When gas production is required, the production well 12 is first opened to discharge the natural gas in the gas storage chamber 21. When the gas pressure in 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 in 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 in each of the first covering chamber 32 and the second covering chamber 33 and the pressure reduction rate of the natural gas in the gas storage chamber 21 is less than or equal to the third preset value.

[0074] Specifically, when gas extraction is required, the natural gas in the gas storage chamber 21 is first discharged. When the pressure in the gas storage chamber 21 is reduced and the pressure in the gas storage chamber 21 is close to the pressure in the first covering chamber 32 (designed operating pressure), the natural gas in the first covering chamber 32 is exhausted. When the pressure in the gas storage chamber 21 is close to the pressure in the second covering chamber 33 (designed operating pressure), the natural gas in the second covering chamber 33 is exhausted. The pressure reduction rate of the natural gas in the first covering chamber 32 and the second covering chamber 33 is 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), so that the pressures of the gas storage chamber 21, the first covering chamber 32 and the second covering chamber 33 are close during the gas extraction process.

[0075] According to the abandoned mine tunnel gas storage of the embodiment of the present invention, a gas storage sealing layer 2 and at least one coating sealing layer 3 are arranged in the abandoned mine tunnel 1, thereby forming a multi-step pressure sealing structure, converting the original single sealing layer strong load into a multi-step weak load, reducing the mechanical strength and construction quality requirements of the sealing layer material during the construction process, and effectively reducing the construction cost of the gas storage. The gas leakage safety redundancy function in the operation of the gas storage can be realized, the leakage risk caused by damage to the single sealing layer is avoided, and the safety of the gas storage system is improved. Compared with the construction method in the related art, it has better advantages in sealing and safety, reduces the requirements of the gas storage for 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 and tunnel utilization rate of different types of abandoned mine tunnel gas storage construction areas.

[0076] In the description of the present invention, it is to 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”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element 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] In addition, 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. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0078] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0079] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0080] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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 described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0081] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary 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 is located in the abandoned mine tunnel, the inner wall surface of the gas storage sealing layer defines a gas storage cavity, the extension direction of the gas storage cavity is consistent with the extension direction of the abandoned mine tunnel, and the gas storage cavity is used to store gas; At least one 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 pass the coating gas.

2. The abandoned mine tunnel gas storage according to claim 1, characterized in that: 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 one located on the outer side of the two adjacent covering cavities covers at least part of the outer side of the one located on the inner side. The covering sealing layer located on the innermost side and the gas storage sealing layer define a covering cavity. The covering sealing layer located on the outermost side is connected to the wall of the abandoned mine tunnel.

3. The abandoned mine tunnel gas storage according to claim 2, characterized in that: On the cross section of the abandoned mine tunnel, the covering cavity is arranged around the outer peripheral side of the gas storage cavity, and one of the two adjacent covering cavities located on the outer side is arranged around 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.

4. The abandoned mine tunnel gas storage according to claim 3, characterized in that: On the cross section of the abandoned mine tunnel, the covering cavity is arranged around the outer peripheral side of the gas storage cavity, and one of the two adjacent covering cavities located on the outer side is arranged around 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.

5. The abandoned mine tunnel gas storage according to claim 2, characterized in that: 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.

6. The abandoned mine tunnel gas storage according to claim 5, characterized in that: The plurality of covering cavities include a first covering cavity and a second covering cavity, and the gas storage cavity, the first covering cavity and the second covering cavity are arranged in sequence from inside to 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 air storage cavity.

7. The abandoned mine tunnel gas storage according to any one of claims 1 to 6, characterized in that: The abandoned mine tunnel gas storage also includes An injection well, the injection well is used to introduce gas into the gas storage chamber, the injection well extends in an up-down direction, and a lower opening of the injection well is communicated with the top of the gas storage chamber; A production well, the production well is used to discharge the gas in the gas storage cavity, the production well extends in the up-down direction, and the lower opening of the production well is connected to the top of the gas storage cavity; 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 of the coating cavities has the sealing well matched therewith.

8. The abandoned mine tunnel gas storage according to claim 7, characterized in that: The injection well, the production well and the sealing well are all provided with pressure monitoring devices.

9. A method for injection and production of gas storage in abandoned mine tunnels using the gas storage in claim 7, 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 at the same time, natural gas is injected into the gas storage cavity through the injection well, and natural gas is injected into the coating cavity through the sealing well, wherein before the gas pressure in the coating cavity reaches its designed operating pressure, the difference between the gas pressure growth rate in the coating cavity and the gas pressure growth 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 whose difference between the designed 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, wherein the difference between the pressure reduction rate of the natural gas in the covering chamber for discharging the natural gas and the pressure reduction rate of the natural gas in the gas storage chamber is less than or equal to a third preset value.

10. The abandoned mine tunnel gas storage injection and production method according to claim 9, 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 inside to 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; 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 needed, first open the production well 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 decreases to two-thirds of its designed operating pressure, open the sealing well on the first covering chamber to discharge the natural gas. When the gas pressure in the gas storage chamber decreases to one-third of its designed operating pressure, open the sealing well on the second covering chamber to discharge the natural gas, wherein 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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