Salt cavern gas storage cement sheath sealing evaluation device and method

Abstract

The invention belongs to the technical field of natural gas storage, and particularly relates to a salt-cavern gas storage cement sheath sealing evaluation device and method. The salt cavern gas storage cement sheath sealing evaluation device comprises a metal inner cylinder, a cement sheath, a salt rock layer and a metal outer cylinder which are sequentially and coaxially sleeved from inside to outside, and sealing covers used for sealing are arranged at the upper ends and the lower ends of the metal inner cylinder and the salt rock layer. The sealing cover is provided with a pressurizing channel used for pressurizing an annular space between the metal inner cylinder and the salt rock layer, and a pressurizing channel used for pressurizing an inner cavity of the metal inner cylinder. The sealing cover is provided with a detection channel used for detecting the sealing performance of a cement sheath between the metal inner cylinder and the salt rock layer, and the metal outer cylinder is of a split structure.

Description

Technical Field

[0001] The present invention belongs to the technical field of natural gas storage, and in particular, relates to a device for evaluating the seal of a cement ring of a salt cavern gas storage and a method for evaluating the seal of a cement ring of a salt cavern gas storage. Background Art

[0002] With the rapid growth of natural gas consumption in my country, the demand for gas storage is more urgent to ensure the emergency peak-shaving reserve demand. There are four main types of underground gas storage: oil and gas reservoir type, salt cavern type, aquifer type and mine pit type. Among them, salt cavern gas storage has the advantages of strong peak-shaving capacity and flexibility, and the construction scale has gradually increased in recent years.

[0003] The injection and production of salt cavern gas storage is more frequent, up to more than ten times a year, and the injection and production rounds far exceed those of gas reservoir-type gas storage. Under the alternating stress and temperature changes caused by multi-cycle strong injection and strong production, the sealing integrity of the cement ring of the oil layer casing faces huge challenges, and the sealing integrity of the cement ring plays an important role in the safe and efficient production of gas storage. Therefore, in order to evaluate whether the cement ring maintains its sealing integrity under strong injection and strong production of salt cavern gas storage, it is necessary to invent a cement ring sealing integrity evaluation device under strong injection and strong production of salt cavern gas storage, and establish a corresponding evaluation method.

[0004] In the prior art, Chinese patent document CN105424331A discloses a device and method for evaluating the mechanical sealing performance of cement sheath during large-scale hydraulic fracturing, which can better test the mechanical properties and mechanical sealing performance of cement sheath, thereby providing data support for the selection of cement slurry system during large-scale hydraulic fracturing, especially for unconventional reservoirs. This evaluation method mainly evaluates the mechanical properties and mechanical sealing performance of cement sheath during large-scale hydraulic fracturing, rather than evaluating the sealing integrity of cement sheath during injection and production of gas storage reservoirs.

[0005] Chinese patent document CN111980675A discloses a method for quantitatively evaluating the integrity of cement ring gas seal, which can quickly and economically evaluate the actual underground cement ring gas seal integrity with high reliability. The method compares the calculated gas leakage volume rate with the allowable leakage volume rate to determine whether the cement ring gas seal integrity has failed.

[0006] Chinese patent document CN114412412A discloses a cement ring seal integrity evaluation device and method. The device and method can evaluate the high-temperature and high-pressure cement ring seal integrity of the overlapping section of the eccentric casing by injecting fluid or heating through the cavity of the inner casing or the cavity between the outer casing and the inner casing, and can simulate the impact of continuous changes in temperature and pressure in the casing on cement ring seal failure.

[0007] Chinese patent document CN115773848A discloses a cement sheath sealing evaluation method, evaluation system and application. By testing the stress of the cement sheath under cyclic loading and unloading, the integrity of the cement sheath structure is evaluated. This method mainly evaluates the mechanical integrity of the cement sheath.

[0008] In the prior art, various simulated wellbores are designed to evaluate the sealing integrity of the cement sheath by pressurizing or heating the inner barrel, but the devices involved cannot accurately simulate the formation, especially the bonding between the formation interface and the cement sheath. Summary of the invention

[0009] In view of the technical problems mentioned above, the present invention aims to provide a salt cavern gas storage cement ring seal evaluation device, which can solve at least one of the above problems.

[0010] The present invention also proposes a method for evaluating the seal of a cement ring of a salt cavern gas storage reservoir, and the method uses the device for evaluating the seal of a cement ring of a salt cavern gas storage reservoir proposed by the present invention.

[0011] According to the present invention, a salt cavern gas storage cement ring sealing evaluation device is provided, comprising a metal inner cylinder, a cement ring, a salt rock layer and a metal outer cylinder which are coaxially sleeved in sequence from the inside to the outside, sealing covers for sealing are arranged at the upper and lower ends of the metal inner cylinder and the salt rock layer, a pressurizing channel for pressurizing the annulus between the metal inner cylinder and the salt rock layer is arranged on the sealing cover, a charging channel for pressurizing the inner cavity of the metal inner cylinder is arranged on the sealing cover, a detection channel for detecting the sealing property of the cement ring between the metal inner cylinder and the salt rock layer is arranged on the sealing cover, and the metal outer cylinder is arranged as a split structure.

[0012] In a preferred embodiment, a first sealing cover is sealed between the upper end of the metal inner tube and the salt rock layer, a second sealing cover is sealed between the lower end of the metal inner tube and the salt rock layer, and a filter is provided between the bottom of the cement ring and the second sealing cover.

[0013] In a preferred embodiment, the charging channel and the pressurizing channel are arranged on the second sealing cover, one end of the charging channel extends axially to the end face of the second sealing cover and connects to the inner cavity of the metal inner tube, the other end of the charging channel extends radially to the side of the second sealing cover, one end of the pressurizing channel extends axially to the end face of the second sealing cover and connects to the annulus between the metal inner tube and the salt rock layer, and the other end of the pressurizing channel extends radially to the side of the second sealing cover.

[0014] In a preferred embodiment, the salt cavern gas storage cement ring seal evaluation device further includes a pressure tracking pump, and the pressure tracking pump is connected to the pressure charging channel.

[0015] In a preferred embodiment, the detection channel is disposed in the first sealing cover, one end of the detection channel axially extends to the end surface of the first sealing cover, and the other end of the detection channel radially extends to the side surface of the first sealing cover.

[0016] In a preferred embodiment, the salt cavern gas storage cement ring seal evaluation device further includes a gas channeling detector, and the gas channeling detector is connected to the detection channel.

[0017] In a preferred embodiment, a heater is arranged inside the metal inner cylinder.

[0018] In a preferred embodiment, a temperature sensor is arranged inside the metal inner cylinder.

[0019] In a preferred embodiment, a cooling pipe is arranged inside the metal inner cylinder.

[0020] According to the present invention, a method for evaluating cement ring seal of a salt cavern gas storage is also provided, and the method comprises the following steps:

[0021] The metal inner cylinder and the salt rock layer are connected to the second sealing cover in sequence, and the metal outer cylinder is arranged outside the salt rock layer;

[0022] A filter screen is arranged at the bottom of the annulus between the metal inner cylinder and the salt rock layer, cement slurry is poured into the annulus, and then cured;

[0023] After the curing is completed, a cement ring is formed, a first sealing cover is installed, and nitrogen gas of a certain pressure is injected into one side of the annulus between the metal inner tube and the salt rock layer through a pressurized channel, and a gas channeling detector is used to detect whether there is gas channeling flow on the other side of the annulus, and a preliminary sealing test is performed;

[0024] After the preliminary sealing test, the internal circulation of the metal inner cylinder is alternately pressurized and cooled and depressurized and heated for multiple times, and a gas channeling detector is used to detect whether there is gas channeling flow.

[0025] Compared with the prior art, the present application has the following advantages.

[0026] The present invention provides a salt cavern gas storage cement ring sealing evaluation device and method. The outer side of the cement ring adopts a salt rock layer, which can accurately simulate the interface bonding between the salt layer section and the cement ring of the salt cavern gas storage. The evaluation method adopts the pressure increase and temperature decrease mode generated when simulating gas injection in the gas storage, and the pressure decrease and temperature increase mode when gas production. The present invention provides technical support for the cement ring sealing integrity under multiple rounds of injection and production in the production cycle of the salt cavern gas storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be described below with reference to the accompanying drawings.

[0028] Figure 1 A schematic diagram of an embodiment of a cement ring seal evaluation device for a salt cavern gas storage according to the present invention is shown.

[0029] In the figure: 1. metal inner tube; 2. cement ring; 3. salt rock layer; 4. cooling pipe; 5. temperature sensor; 6. heater; 7. first sealing cover; 8. second sealing cover; 9. metal outer tube; 10. first clamp; 11. support frame; 12. second clamp; 13. pressure tracking pump; 14. gas channeling detector; 15. pressurizing channel; 16. filter; 17. detection channel; 18. pressurizing channel; 100. cement ring seal evaluation device for salt cavern gas storage.

[0030] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0031] The present invention will be described below with reference to the accompanying drawings.

[0032] It should be noted that the directional terms or qualifiers "upper" and "lower" used in this application are all directed to the referenced Figure 1 They are not intended to define the absolute positions of the components involved, but may vary depending on the specific circumstances.

[0033] Embodiment 1:

[0034] Figure 1 The structure of the cement ring seal evaluation device 100 of the salt cavern gas storage according to the present invention is shown. Figure 1 As shown, the cement ring sealing evaluation device 100 for a salt cavern gas storage comprises a metal inner cylinder 1, a cement ring 2, a salt rock layer 3 and a metal outer cylinder 9 which are coaxially sleeved in sequence from the inside to the outside.

[0035] In this embodiment, the salt rock layer 3 is made of salt rock blocks. First, a salt rock block of a certain size is prepared, the height and cross-sectional dimensions of which are larger than the required size of the salt rock layer 3, and then the salt rock block is cut into a cylinder using a circular cutter, the diameter of the cylinder is equal to the outer diameter of the salt rock layer 3, and finally a circular cutter of a slightly smaller size is used to cut the inside of the salt rock cylinder into a cylinder, the inner diameter of which is the inner diameter of the salt rock layer 3.

[0036] The present invention uses the salt rock layer 3 to more realistically simulate the bonding between the cement sheath 2 and the salt rock stratum.

[0037] In this embodiment, the metal outer cylinder 9 is configured as a split structure. In a specific embodiment, the metal outer cylinder 9 includes two semicircular cylinders (not shown in the figure), which are adapted to each other to form the metal outer cylinder 9.

[0038] In a preferred embodiment, at least one clamp is provided outside the metal outer tube 9. Figure 1 As shown, a second clamp 12 is provided on the upper outer portion of the metal outer tube 9, and a first clamp 10 is provided on the lower outer portion of the metal outer tube 9. The first clamp 10 and the second clamp 12 are coaxially sleeved on the outside of the metal outer tube 9 to fix the metal outer tube 9 and prevent the two semicircular cylinders constituting the metal outer tube 9 from spreading.

[0039] By setting the metal outer cylinder 9 of the split structure, on the one hand, it is easy to assemble, so that the salt rock layer 3 can fit tightly with the metal outer cylinder 9. It is difficult to set the salt rock layer 3 inside the metal outer cylinder 9 using the cylindrical structure in the prior art. Even after the salt rock layer 3 is loaded into the metal outer cylinder 9, it is easy for the two to not fit tightly, and the effect of effectively restraining the salt rock layer 3 cannot be achieved. The metal outer cylinder 9 of the split structure of the present invention makes it difficult for the salt rock layer 3 to be structurally damaged when loaded.

[0040] On the other hand, after the experiment is finished, the metal outer cylinder 9 can be quickly separated from the salt rock layer 3 for easy disassembly.

[0041] Sealing covers for sealing are arranged at the upper and lower ends of the metal inner tube 1 and the salt rock layer 3, a pressurizing channel 18 for pressurizing the annulus between the metal inner tube 1 and the salt rock layer 3 is arranged on the sealing cover, a charging channel 15 for pressurizing the inner cavity of the metal inner tube 1 is arranged on the sealing cover, and a detection channel 17 for detecting the sealing performance of the cement ring 2 between the metal inner tube 1 and the salt rock layer 3 is arranged on the sealing cover.

[0042] According to the present invention, a first sealing cover 7 is sealedly arranged at the upper end of the metal inner tube 1 and the salt rock layer 3, and a second sealing cover 8 is sealedly arranged at the lower end of the metal inner tube 1 and the salt rock layer 3. The first sealing cover 7 and the second sealing cover 8 are similar in shape, and both include a large diameter portion and a small diameter portion. Among them, the small diameter portion of the first sealing cover 7 and the second sealing cover 8 is arranged in the metal inner tube 1 by a sealed connection, and the large diameter portion of the first sealing cover 7 and the second sealing cover 8 forms a seal with the metal inner tube 1 and the salt rock layer 3 by axial abutment.

[0043] Furthermore, a sealing ring (not shown in the figure) is provided on the cylindrical side surface of the small diameter portion of the first sealing cover 7 and the second sealing cover 8, and a sealing ring (not shown in the figure) is provided at the position where the large diameter portion of the first sealing cover 7 and the second sealing cover 8 abuts against the salt rock layer 3.

[0044] In a preferred embodiment, a filter screen 16 is provided between the bottom of the cement ring 2 and the second sealing cover 8 .

[0045] In a specific embodiment, the filter screen 16 is made of asbestos material.

[0046] In the assembly process of the present invention, the metal inner cylinder 1 and the salt rock layer 3 are first coaxially sleeved on the second sealing cover 8 in sequence, and then the metal outer cylinder 9 is sleeved on the salt rock layer 3 through the first clamp 10 and the second clamp 12. The filter screen 16 is arranged in the annulus between the metal inner cylinder 1 and the salt rock layer 3 and contacts with the second sealing cover 8, and then cement slurry is poured into the annulus between the metal inner cylinder 1 and the salt rock layer 3. By setting the filter screen 16, the cement slurry can be prevented from entering the pressurized channel 18 and blocking it.

[0047] In a specific embodiment, the charging channel 15 and the pressurizing channel 18 are arranged on the second sealing cover 8. Figure 1 As shown, the charging channel 15 and the pressurizing channel 18 are both configured as L-shaped structures.

[0048] One end of the charging channel 15 axially extends to the end surface of the small diameter portion of the second sealing cover 8, communicating with the inner cavity of the metal inner tube 1, and the other end of the charging channel 15 radially extends to the side of the second sealing cover 8. The inner cavity pressure of the metal inner tube 1 can be controlled through the charging channel 15.

[0049] It should be noted that the charging channel 15 may also be disposed in the first sealing cover 7 .

[0050] One end of the pressurized channel 18 axially extends to the end face of the large diameter portion of the second sealing cover 8, connecting the annulus between the metal inner tube 1 and the salt rock layer 3, and the other end of the pressurized channel 18 radially extends to the side of the second sealing cover 8. The pressurized channel 18 can be used to pressurize the annulus between the metal inner tube 1 and the salt rock layer 3 to simulate the formation environmental pressure.

[0051] Specifically, the salt cavern gas storage cement ring seal evaluation device further includes a pressure tracking pump 13 , and the pressure tracking pump 13 is connected to the pressure charging channel 15 .

[0052] According to the present invention, the detection channel 17 is arranged in the first sealing cover 7, one end of the detection channel 17 axially extends to the end face of the large diameter portion of the first sealing cover 7, and is connected to the annulus between the metal inner tube 1 and the salt rock layer 3, and the other end of the detection channel 17 radially extends to the side of the first sealing cover 7. If the seal inside or outside the cement ring 2 fails, the gas channeling flow rate can be detected in the detection channel 17, so whether the cement ring 2 fails in sealing can be detected through the detection channel 17.

[0053] The salt cavern gas storage cement ring seal evaluation device further includes a gas channeling detector 14 , which is connected to a detection channel 17 .

[0054] In a preferred embodiment, a heater 6 is provided inside the metal inner tube 1. The heater 6 is provided in a cylindrical shape and is coaxially sleeved inside the metal inner tube 1. The heater 6 can increase the temperature of the metal inner tube 1. On the one hand, it can maintain the metal inner tube 1 and the salt rock layer 3 when cement slurry is added thereto, and on the other hand, it can provide temperature conditions for the experiment.

[0055] In a preferred embodiment, a temperature sensor 5 is disposed inside the metal inner tube 1 , and the temperature sensor 5 coincides with the central axis of the metal inner tube 1 .

[0056] In a preferred embodiment, a cooling pipe 4 is arranged inside the metal inner tube 1. The cooling pipe 4 is arranged in a spiral shape and is arranged inside the metal inner tube 1 in a spirally wound manner.

[0057] Furthermore, the upper and lower ends of the cooling pipe 4 pass through the first sealing cover 7 and the second sealing cover 8 respectively, and are connected to a circulation mechanism (not shown in the figure). The circulation mechanism can provide cold water for the cooling pipe 4 and circulate the cold water in the cooling pipe 4, thereby quickly cooling the interior of the metal inner tube 1.

[0058] In a preferred embodiment, the salt cavern gas storage cement ring seal evaluation device 100 further includes a support frame 11 , which abuts against an upper end surface of the first sealing cover 7 and a lower end surface of the second sealing cover 8 .

[0059] Embodiment 2:

[0060] In one embodiment of the present invention, a method for evaluating cement ring seal of a salt cavern gas storage is provided. The method is performed using a device 100 for evaluating cement ring seal of a salt cavern gas storage.

[0061] A method for evaluating cement ring seal of a salt cavern gas storage reservoir comprises the following steps.

[0062] The metal inner tube 1 and the salt rock layer 3 are connected to the second sealing cover 8 in sequence, and the metal outer tube 9 is arranged on the outside of the salt rock layer 3 by using the first clamp 10 and the second clamp 12 .

[0063] A filter screen 16 is set at the bottom of the annulus between the metal inner tube 1 and the salt rock layer 3, and cement slurry is poured into it. The metal inner tube 1 is filled with water and heated to the temperature required for curing by a heater 6. The temperature is detected by a temperature sensor 5, and the cement ring 2 is cured for 72 hours using the heater 6.

[0064] After the maintenance is completed, the cement ring 2 is formed, and the first sealing cover 7 is installed to seal the upper end of the annulus between the metal inner tube 1 and the salt rock layer 3. The support frame 11 is used to abut the upper end surface of the first sealing cover 7 and the lower end surface of the second sealing cover 8 respectively. A certain pressure of nitrogen is injected into one side of the annulus between the metal inner tube 1 and the salt rock layer 3, and a gas channeling detector 14 is used to detect whether there is a gas channeling flow on the other side of the annulus, and a preliminary sealing test is performed. In this embodiment, a certain pressure of nitrogen is injected into the lower side of the annulus between the metal inner tube 1 and the salt rock layer 3 through the pressurized channel 18, and a gas channeling detector 14 is used to detect whether there is a gas channeling flow on the upper side of the annulus between the metal inner tube 1 and the salt rock layer 3 through the detection channel 17, so as to ensure that the cement ring 2 can form an effective seal with the metal inner tube 1 and the salt rock layer 3 before the experiment.

[0065] After the preliminary sealing test, the temperature of the metal inner tube 1 is adjusted using the heater 6 and the cooling tube 4, and the pressure in the metal inner tube 1 is adjusted using the pressure tracking pump 13. The internal circulation of the metal inner tube 1 is alternately pressurized and cooled and depressurized and heated for multiple times, and the gas channeling detector 14 is used to detect whether there is gas channeling flow. If the sealing integrity of the cement ring 2 fails, the test is stopped; if it does not fail, the cycle is repeated for more than 300 times.

[0066] Embodiment three:

[0067] In this embodiment, the cement ring 2 is made of salt-resistant elastic toughness cement slurry. During the curing process of the cement ring 2, water is injected into the metal inner tube 1 until it is full. The temperature is set to 70°C and heated for 72 hours. Nitrogen at a pressure of 1.0MPa is introduced between the metal inner tube 1 and the salt rock layer 3 through the pressurized channel 18 to check whether the sealing of the cement ring 2 is intact. After checking that the seal is intact, the inner cavity of the metal inner tube 1 is gradually pressurized to 35MPa using the pressure tracking pump 13, and the cooling water is circulated to 25°C using the cooling pipe 4. At the same time, the gas channeling detector 14 is used to detect whether there is gas in the detection channel 17. After the pressure and temperature reach the set value at the same time, the constant pressure and temperature are maintained for 30 minutes. After that, the pressure is relieved and the temperature is lowered, the pressure drops to 0 and the temperature rises to 70°C, and the constant pressure and temperature are maintained for 30 minutes. This cycle is repeated 300 times, and no gas channeling occurs.

[0068] The remaining technical features of this embodiment are the same as those of the aforementioned embodiment.

[0069] After testing, the salt-resistant elastic toughness cement ring 2 can meet the sealing integrity requirements of withstanding 300 cycles of alternating stress with an internal pressure of 0 to 35 MPa and a temperature difference of 25 to 70°C.

[0070] Embodiment 4:

[0071] In this embodiment, the cement ring 2 is made of ordinary salt-resistant cement slurry.

[0072] The remaining technical features of this embodiment are the same as those of the third embodiment.

[0073] After testing, it was found that the ordinary salt-resistant cement ring experienced gas channeling after being subjected to alternating stress of internal pressure of 0 to 35 MPa and temperature difference of 25 to 70°C for 105 cycles, and the sealing integrity failed.

[0074] Embodiment five:

[0075] In this embodiment, the cement ring 2 is made of ordinary cementing slurry.

[0076] The test showed that gas channeling occurred when checking the sealing of the cement ring before pressurization and temperature change, indicating that ordinary cement slurry has no salt resistance and poor bonding with the salt rock interface.

[0077] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, 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 connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two components. 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 description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" means 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 representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0080] Finally, it should be noted that the above is only a preferred embodiment of the present invention and does not constitute any limitation to the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments or to replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A salt cavern gas storage cement ring seal evaluation device, characterized in that: The invention comprises a metal inner cylinder (1), a cement ring (2), a salt rock layer (3) and a metal outer cylinder (9) which are coaxially sleeved in sequence from the inside to the outside. Sealing covers for sealing are arranged at the upper and lower ends of the metal inner cylinder (1) and the salt rock layer (3). The sealing cover is provided with a pressurizing channel (18) for pressurizing the annular space between the metal inner cylinder (1) and the salt rock layer (3). The sealing cover is provided with a charging channel (15) for pressurizing the inner cavity of the metal inner cylinder (1). The sealing cover is provided with a detection channel (17) for detecting the sealing performance of the cement ring (2) between the metal inner cylinder (1) and the salt rock layer (3). The metal outer cylinder (9) is arranged as a split structure.

2. The salt cavern gas storage cement ring seal evaluation device according to claim 1 is characterized in that: A first sealing cover (7) is sealed between the upper ends of the metal inner cylinder (1) and the salt rock layer (3), a second sealing cover (8) is sealed between the lower ends of the metal inner cylinder (1) and the salt rock layer (3), and a filter screen (16) is provided between the bottom of the cement ring (2) and the second sealing cover (8).

3. The salt cavern gas storage cement ring seal evaluation device according to claim 2 is characterized in that: The charging channel (15) and the pressurizing channel (18) are arranged on the second sealing cover (8), One end of the charging channel (15) axially extends to the end surface of the second sealing cover (8) and communicates with the inner cavity of the metal inner cylinder (1), and the other end of the charging channel (15) radially extends to the side surface of the second sealing cover (8). One end of the pressurized channel (18) extends axially to the end surface of the second sealing cover (8) to communicate with the annular space between the metal inner tube (1) and the salt rock layer (3), and the other end of the pressurized channel (18) extends radially to the side surface of the second sealing cover (8).

4. The salt cavern gas storage cement ring seal evaluation device according to claim 3 is characterized in that: The salt cavern gas storage cement ring seal evaluation device further comprises a pressure tracking pump (13), and the pressure tracking pump (13) is connected to the pressure charging channel (15).

5. The salt cavern gas storage cement ring seal evaluation device according to claim 2, characterized in that: The detection channel (17) is arranged in the first sealing cover (7), one end of the detection channel (17) extends axially to the end surface of the first sealing cover (7), and the other end of the detection channel (17) extends radially to the side surface of the first sealing cover (7).

6. The salt cavern gas storage cement ring seal evaluation device according to claim 5, characterized in that: The salt cavern gas storage cement ring seal evaluation device further comprises a gas channeling detector (14), and the gas channeling detector (14) is connected to the detection channel (17).

7. The cement ring seal evaluation device for salt cavern gas storage according to any one of claims 1 to 6, characterized in that: A heater (6) is arranged inside the metal inner cylinder (1).

8. The salt cavern gas storage cement ring seal evaluation device according to claim 7, characterized in that: A temperature sensor (5) is arranged inside the metal inner cylinder (1).

9. The salt cavern gas storage cement ring seal evaluation device according to claim 7, characterized in that: A cooling pipe (4) is arranged inside the metal inner tube (1).

10. A method for evaluating cement ring seal of a salt cavern gas storage, characterized in that: Using the cement ring seal evaluation device for salt cavern gas storage according to any one of claims 1 to 9 comprises the following steps: The metal inner cylinder (1) and the salt rock layer (3) are sequentially connected to the second sealing cover (8), and the metal outer cylinder (9) is arranged outside the salt rock layer (3); A filter screen (16) is arranged at the bottom of the annulus between the metal inner cylinder (1) and the salt rock layer (3), cement slurry is poured into the annulus, and then cured; After the curing is completed, a cement ring (2) is formed, a first sealing cover (7) is installed, and nitrogen gas at a certain pressure is injected into one side of the annulus between the metal inner tube (1) and the salt rock layer (3) through a pressurized channel (18), and a gas channeling detector (14) is used to detect whether there is gas channeling flow on the other side of the annulus, and a preliminary sealing test is performed; After the preliminary sealing test, the internal circulation of the metal inner cylinder (1) is alternately subjected to multiple pressurization and cooling and pressure relief and heating, and a gas channeling detector (14) is used to detect whether there is gas channeling flow.

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