Salt cavern hydrogen storage verification system, and construction method and verification method therefor

Abstract

Disclosed are a salt cavern hydrogen storage verification system, and a construction method and a verification method therefor. The salt cavern hydrogen storage verification system comprises a hydrogen storage test well (15), a hydrogen buffer well (25), and a hydrogen delivery assembly. A gas injection and production pipe (12) extends into a wellbore of the hydrogen storage test well, a first brine discharge pipe (13) extends into the gas injection and production pipe, a lower end opening of the first brine discharge pipe extends into the bottom of a salt cavern of the hydrogen storage test well, and a first annulus is formed between the gas injection and production pipe and the first brine discharge pipe. A second brine discharge pipe (29) extends into a wellbore of the hydrogen buffer well, a lower end opening of the second brine discharge pipe extends into the bottom of a salt cavern of the hydrogen buffer well, and a second annulus is formed between the wellbore of the hydrogen buffer well and the second brine discharge pipe. The hydrogen delivery assembly comprises hydrogen piping (17) and a compressor (18) connected in series to the hydrogen piping. Two ends of the gas injection and production pipe are respectively connected to openings of the first annulus and the second annulus. The salt cavern hydrogen storage verification system can effectively evaluate the feasibility of storing hydrogen in salt caverns.

Description

Salt cavern hydrogen storage verification system, construction method and verification method thereof TECHNICAL FIELD

[0001] The present application relates to the field of geological hydrogen storage, in particular to a salt cavern hydrogen storage verification system, a construction method and a verification method thereof. BACKGROUND

[0002] Hydrogen is a widely used, clean and safe energy carrier, and is widely used in the field of power fuel or industrial raw materials. With the maturity of hydrogen production technology and cost reduction, the scope of hydrogen energy utilization is continuously expanding. Hydrogen energy storage, as a new type of energy storage method, has significant advantages in energy dimension, time dimension and space dimension, and therefore plays an important role in the construction of new power systems. Compared with other hydrogen energy storage methods, geological hydrogen storage has the advantages of large scale, long cycle, cross-season energy storage, etc., and is an important development direction for large-scale hydrogen energy storage in the future. Among them, salt caverns, due to their wide distribution, large scale, simple geological structure and hydrological conditions, and excellent sealing performance, are expected to become the preferred type for large-scale underground hydrogen storage coupled with electricity in the future.

[0003] The present application relates to the field of geological hydrogen storage, in particular to a salt cavern hydrogen storage verification system, a construction method and a verification method thereof.

[0004] In order to solve the above problems, it is necessary to establish a salt cavern hydrogen storage verification system, a construction method and a verification method thereof. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide a salt cavern hydrogen storage verification system which can effectively evaluate the feasibility of salt cavern hydrogen storage.

[0006] To solve the above technical problems, the technical scheme of the present application is as follows: a salt cavern hydrogen storage verification system, comprising:

[0007] a hydrogen storage test well, a gas injection and production pipe is inserted into the wellbore, a first halogen discharge pipe is inserted into the gas injection and production pipe, the lower end of the first halogen discharge pipe is inserted into the bottom of the salt cavern of the hydrogen storage test well, and a first annulus is formed between the gas injection and production pipe and the first halogen discharge pipe;

[0008] a hydrogen gas buffer well, a second halogen discharge pipe is inserted into the wellbore, the lower end of the second halogen discharge pipe is inserted into the bottom of the salt cavern of the hydrogen gas buffer well, and a second annulus is formed between the wellbore of the hydrogen gas buffer well and the second halogen discharge pipe;

[0009] The hydrogen delivery assembly comprises a hydrogen pipeline and a compressor connected in series with the hydrogen pipeline, and the injection-production gas pipe is connected with the openings of the first and second annuli respectively.

[0010] Further, in order to ensure the stability of the two salt caverns, the distance between the salt cavern of the hydrogen storage test well and the salt cavern of the hydrogen buffer well is not less than the sum of the maximum diameters of the two salt caverns.

[0011] Further, in order to facilitate the opening and closing of each opening, a valve one is arranged at the opening of the first halogen discharge pipe, a pressure gauge one, a valve two and a flow meter one are arranged at the opening of the first annulus, a third annulus is formed between the wellbore of the hydrogen storage test well and the injection-production gas pipe, and a pressure gauge two and a valve three are arranged at the opening of the third annulus.

[0012] A valve four and a flow meter two are arranged at the opening of the second halogen discharge pipe, and a pressure gauge three, a valve five and a flow meter three are arranged at the opening of the second annulus.

[0013] Further, the wellbores of the hydrogen storage test well and the hydrogen buffer well are each provided with a guide pipe, a surface casing and a production casing.

[0014] The guide pipe is consolidated with the formation by cementing;

[0015] The surface casing is arranged in the guide pipe and is consolidated with the guide pipe and the formation by cementing, and the lower end thereof extends downward beyond the guide pipe without extending into the rock salt layer.

[0016] The production casing is arranged in the surface casing and is consolidated with the surface casing and the formation by cementing, and the lower end thereof extends downward beyond the surface casing and extends into the rock salt layer.

[0017] Further, the salt cavern hydrogen storage verification system further comprises a wellhead gas production tree and a wellhead gas injection and halogen production tree.

[0018] The wellhead gas production tree is provided with a first gas injection-production channel, a first halogen discharge channel and a monitoring channel, the first gas injection-production channel is connected with the injection-production gas pipe, the first halogen discharge channel is connected with the first halogen discharge pipe, and the monitoring channel is connected with the production casing of the hydrogen storage test well.

[0019] The wellhead gas injection and halogen production tree is provided with a second gas injection-production channel and a second halogen discharge channel, the second gas injection-production channel is connected with the production casing of the hydrogen buffer well, and the second halogen discharge channel is connected with the second halogen discharge pipe.

[0020] The present application also relates to a construction method of a salt cavern hydrogen storage verification system, which comprises the following steps:

[0021] S1, select two salt caves with completed cavities as a hydrogen storage test salt cave and a hydrogen buffer salt cave respectively;

[0022] S2, the first gas tightness detection is carried out on the two salt caves, and after passing the detection, the two salt caves are reformed to form a hydrogen storage test well and a hydrogen buffer well;

[0023] S3, the second gas tightness detection is carried out on the hydrogen storage test well and the hydrogen buffer well, and after passing the detection, hydrogen is injected into the injection-production gas pipe of the hydrogen storage test well to discharge the brine in the hydrogen storage test well;

[0024] S4, after the brine in the hydrogen storage test well is discharged, hydrogen is continuously injected until the pressure rises to the upper limit of the test pressure, the first annulus of the hydrogen storage test well and the second annulus of the hydrogen buffer well are connected through a hydrogen pipeline, and a compressor is installed.

[0025] Further, in step S1, the peak regulation capacity of the hydrogen storage test salt cave in the test pressure range is not greater than the maximum gas storage capacity of the hydrogen buffer salt cave;

[0026] In steps S2 and S3, when the gas tightness detection is carried out, nitrogen is used for the gas tightness detection first, and then hydrogen is used for the gas tightness detection after passing the nitrogen detection.

[0027] The application also relates to a verification method of a salt cave hydrogen storage verification system, which comprises the following steps:

[0028] R1, the openings of the first annulus, the second annulus and the second brine discharge pipe are opened, hydrogen flows from the hydrogen storage test well to the hydrogen buffer well through the hydrogen pipeline, and the brine in the hydrogen buffer well flows out through the second brine discharge pipe;

[0029] R2, when the pressure of the hydrogen storage test well decreases to the lower limit of the test pressure, the openings of the first annulus, the second annulus and the second brine discharge pipe are closed, and the volume of hydrogen flowing out of the hydrogen storage test well and the volume of hydrogen injected into the hydrogen buffer well are recorded;

[0030] R3, after the hydrogen storage test well and the hydrogen buffer well are shut down for a preset time, the openings of the first annulus, the second annulus and the second brine discharge pipe are opened, the brine is injected into the hydrogen buffer well through the second brine discharge pipe, the hydrogen in the hydrogen buffer well flows to the hydrogen storage test well through the hydrogen pipeline, after the hydrogen in the hydrogen buffer well is completely produced, the openings of the first annulus, the second annulus and the second brine discharge pipe are closed, and the volume of hydrogen flowing out of the hydrogen buffer well and the volume of hydrogen injected into the hydrogen storage test well are recorded;

[0031] R4, after the hydrogen storage test well and the hydrogen buffer well are shut down for a period of time, return to step R1 until the cycle reaches a preset number of times;

[0032] R5, the hydrogen leakage rate of the hydrogen storage test well in each test cycle is counted, and if the requirement is met, the hydrogen storage test well is put into use in the salt cave hydrogen storage library.

[0033] Further, after the openings of the first annulus, the second annulus and the second brine discharge pipe are opened in step S1, hydrogen in the hydrogen storage test well flows to the hydrogen buffer well through the hydrogen pipeline under the action of the pressure difference, and if the pressure of the hydrogen storage test well does not reach the lower limit of the test pressure when reaching the balance, the compressor is started to pressurize until the pressure of the hydrogen storage test well reaches the lower limit of the test pressure.

[0034] After the above technical scheme is adopted, the hydrogen injection and hydrogen production process is simulated under actual operation conditions by cooperation of the hydrogen storage test well and the hydrogen buffer well, high-frequency alternating pressure in the actual working condition of the hydrogen storage test well is simulated, and the problems of a large amount of hydrogen source and destination are solved. Therefore, the feasibility of salt cavern hydrogen storage can be well tested and verified, and a basis is provided for further optimization and application of salt cavern hydrogen storage technology. BRIEF DESCRIPTION OF DRAWINGS

[0035] Fig. 1 is a structural schematic diagram of the salt cavern hydrogen storage verification system of the present application;

[0036] Fig. 2 is a structural schematic diagram of the salt cavern hydrogen storage verification system of the present application before being built;

[0037] Fig. 3 is a structural schematic diagram of the present application in which hydrogen produced from the hydrogen storage test well is injected into the hydrogen buffer well;

[0038] Fig. 4 is a structural schematic diagram of the salt cavern hydrogen storage verification system of the present application for subsequent use; 1, valve one; 2, wellhead gas production tree; 3, pressure gauge one; 4, flow meter one; 5, valve two; 6, pressure gauge two; 7, valve three; 8, guide pipe; 9, surface casing; 10, production casing; 11, downhole safety valve; 12, injection and production gas pipe; 13, first brine discharge pipe; 14, packer; 15, hydrogen storage test well; 16, hydrogen; 17, hydrogen pipeline; 18, compressor; 19, flow meter two; 20, wellhead gas injection and brine production tree; 21, valve four; 22, pressure gauge three; 23, flow meter three; 24, valve five; 25, hydrogen buffer well; 26, brine; 27, hydrogen storage salt cavern; 28, hydrogen buffer salt cavern; 29, second brine discharge pipe. DETAILED DESCRIPTION

[0039] In order to make the content of the present application more easily understood, the present application will be further described in detail below according to specific embodiments and in combination with the accompanying drawings.

[0040] Example One

[0041] As shown in Figs. 1 to 4, a salt cavern hydrogen storage verification system comprises:

[0042] a hydrogen storage test well 15, a well bore of which extends into the injection-production gas pipe 12, the injection-production gas pipe 12 extends into the first halogen discharge pipe 13, a lower end of the first halogen discharge pipe 13 extends into a bottom of a salt cavern of the hydrogen storage test well 15, and a first annulus is formed between the injection-production gas pipe 12 and the first halogen discharge pipe 13;

[0043] a hydrogen buffer well 25, a well bore of which extends into the second halogen discharge pipe 29, a lower end of the second halogen discharge pipe 29 extends into a bottom of a salt cavern of the hydrogen buffer well 25, and a second annulus is formed between the well bore of the hydrogen buffer well 25 and the second halogen discharge pipe 29;

[0044] a hydrogen delivery assembly, which comprises the hydrogen pipe 17 and the compressor 18 connected in series with the hydrogen pipe 17, and the two ends of the injection-production gas pipe 12 are connected to openings of the first annulus and the second annulus respectively.

[0045] In the embodiment, the well bores of the hydrogen storage test well 15 and the hydrogen buffer well 25 are each provided with the guide pipe 8, the surface casing 9 and the production casing 10; the guide pipe 8 is consolidated with the formation by cementing; the surface casing 9 is arranged in the guide pipe 8 and consolidated with the guide pipe 8 and the formation by cementing, and the lower end thereof extends downward beyond the guide pipe 8 and does not extend into the rock salt layer; and the production casing 10 is arranged in the surface casing 9 and consolidated with the surface casing 9 and the formation by cementing, and the lower end thereof extends downward beyond the surface casing 9 and extends into the rock salt layer.

[0046] In the embodiment, in consideration of the influence of the stability of the salt cavern, when the hydrogen storage test well 15 and the hydrogen buffer well 25 are selected, a certain distance should be kept between the two wells, and the distance between the salt cavern of the hydrogen storage test well 15 and the salt cavern of the hydrogen buffer well 25 is preferably not less than the sum of the maximum diameters of the two salt caverns. For example, if the maximum diameter of the salt cavern of the hydrogen storage test well 15 is 70 m and the maximum diameter of the salt cavern of the hydrogen buffer well 25 is 80 m, the distance between the two should be not less than 150 m.

[0047] In the embodiment, as shown in FIGS. 1 to 4, the valve one 1 is arranged at the opening of the first halogen discharge pipe 13, the pressure gauge one 3, the valve two 5 and the flow meter one 4 are arranged at the opening of the first annulus, the third annulus is formed between the well bore of the hydrogen storage test well 15 and the injection-production gas pipe 12, the pressure gauge two 6 and the valve three 7 are arranged at the opening of the third annulus, the valve four 21 and the flow meter two 19 are arranged at the opening of the second halogen discharge pipe 29, and the pressure gauge three 22, the valve five 24 and the flow meter three 23 are arranged at the opening of the second annulus. In this way, each opening can be conveniently opened and closed.

[0048] In the embodiment, as shown in FIGS. 1, 3 and 4, the salt cavern hydrogen storage verification system further comprises the wellhead gas production tree 2 and the wellhead gas injection and halogen production tree 20; wherein,

[0049] The wellhead gas production tree 2 is provided with a first gas injection and production channel, a first brine discharge channel and a monitoring channel, the first gas injection and production channel is connected with the gas injection and production pipe 12; the first brine discharge channel is connected with the first brine discharge pipe 13, and the monitoring channel is connected with the production casing pipe 10 of the hydrogen storage test well 15.

[0050] The wellhead gas injection and brine discharge tree 20 is provided with a second gas injection and production channel and a second brine discharge channel, the second gas injection and production channel is connected with the production casing pipe 10 of the hydrogen buffer well 25, and the second brine discharge channel is connected with the second brine discharge pipe 29.

[0051] Embodiment two

[0052] A construction method of the salt cavern hydrogen storage verification system as in embodiment one, the method comprising:

[0053] S1, selecting two salt caverns which have completed cavity forming as the hydrogen storage test salt cavern 27 and the hydrogen buffer salt cavern 28 respectively, and ensuring that the hydrogen buffer salt cavern 28 can completely store the hydrogen gas extracted from the hydrogen storage test salt cavern 27, and the peak regulation capacity of the hydrogen storage test salt cavern 27 in the test pressure range is not greater than the maximum gas storage capacity of the hydrogen buffer salt cavern 28;

[0054] S2, performing first gas tightness detection on the two salt caverns, and after passing the detection, performing modification on the two salt caverns to form the hydrogen storage test well 15 and the hydrogen buffer well 25.

[0055] The specific process of the first gas tightness detection is to perform detection on the gas tightness of the two salt caverns by adopting the combined test method of nitrogen and hydrogen, first detecting by using nitrogen as the gas medium, and then detecting by using hydrogen as the gas medium after passing the detection by nitrogen. The gas tightness test steps of the two wells can refer to the patent application with the application number CN200510075290.7 and the patent name of salt cavern gas storage cavity body tightness pressure test method. After the hydrogen gas tightness test of the two salt caverns is passed, the two salt caverns are modified. As shown in FIG. 2, the cavity forming tree which only allows brine to enter and exit is used during the cavity forming of the salt cavern, and the cavity forming tree cannot be used continuously in the salt cavern hydrogen storage verification system which involves hydrogen injection and extraction. Therefore, the wellhead gas production tree 2 and the wellhead gas injection and brine discharge tree 20 which are suitable for hydrogen injection and extraction are used. In addition to verifying the tightness of the hydrogen storage in the salt cavern, the tightness of some pipe strings and downhole tools in the hydrogen storage cavern is also verified. Therefore, the gas injection and production pipe 12, the downhole safety valve 11 and the packer 14 are lowered into the hydrogen storage test well 15.

[0056] S3, performing second gas tightness detection on the hydrogen storage test well 15 and the hydrogen buffer well 25, and after passing the detection, injecting hydrogen 16 into the gas injection and production pipe 12 of the hydrogen storage test well 15 and discharging the brine 26 in the hydrogen storage test well 15.

[0057] The specific process of the second airtightness detection is that nitrogen is used to detect the airtightness, and after passing the detection, hydrogen is used to detect the airtightness, and the steps of the second airtightness detection are the same as those of the first airtightness detection. After passing the detection, hydrogen is injected into the hydrogen storage test well 15 through the first injection and production gas channel of the wellhead gas tree 2, the hydrogen is injected into the hydrogen storage test well 15 through the injection and production gas pipe 12, and the brine 26 is discharged through the first brine discharge pipe 13.

[0058] S4, after the brine 26 in the hydrogen storage test well 15 is emptied, hydrogen 16 is continuously injected until the pressure rises to the upper limit of the test pressure, the first annulus of the hydrogen storage test well 15 is connected with the second annulus of the hydrogen buffer well 25 through the hydrogen pipeline 17, and the compressor 18 is installed.

[0059] Example three

[0060] A verification method of the salt cavern hydrogen storage verification system as in example one, the method comprising:

[0061] R1, open the openings of the first annulus, the second annulus and the second brine discharge pipe 29, that is, open the valve two 5, the valve five 24 and the valve four 21 shown in FIG. 1, the hydrogen 16 flows from the hydrogen storage test well 15 to the hydrogen buffer well 25 through the hydrogen pipeline 17, and the brine 26 in the hydrogen buffer well 25 flows out through the second brine discharge pipe 29.

[0062] When this step is performed, the hydrogen 16 in the hydrogen storage test well 15 will flow to the hydrogen buffer well 25 through the hydrogen pipeline 17 under the action of the pressure difference, and when the balance is reached, the pressure of the hydrogen storage test well 15 still does not reach the lower limit of the test pressure, the compressor 18 needs to be started to pressurize until the pressure of the hydrogen storage test well 15 reaches the lower limit of the test pressure.

[0063] R2, when the pressure of the hydrogen storage test well 15 decreases to the lower limit of the test pressure, the openings of the first annulus, the second annulus and the second brine discharge pipe 29 are closed, that is, the valve two 5, the valve five 24 and the valve four 21 shown in FIG. 1 are closed, as shown in FIG. 3, at this time, there is also hydrogen in the hydrogen buffer well 25.

[0064] In this step, the volume of hydrogen flowing out of the hydrogen storage test well 15 is recorded by the flowmeter one 4, and the volume of hydrogen injected into the hydrogen buffer well 25 is recorded by the flowmeter three 23. The values of the two should be the same, and in the case that there is no hydrogen leakage in the hydrogen pipeline 17, it is considered that the volume of hydrogen extracted from the hydrogen storage test well 15 should be equal to the volume of hydrogen injected into the hydrogen buffer well 25.

[0065] R3, the hydrogen storage test well 15 and the hydrogen buffer well 25 are closed for a predetermined time, the first annulus, the second annulus and the opening of the second halogen discharge pipe 29 are opened, that is, the valve two 5, the valve five 24 and the valve four 21 shown in Fig. 1 are opened, the brine 26 is injected into the hydrogen buffer well 25 through the second halogen discharge pipe 29, and the hydrogen 16 in the hydrogen buffer well 25 flows to the hydrogen storage test well 15 through the hydrogen pipeline 17. After the hydrogen 16 in the hydrogen buffer well 25 is completely produced, the opening of the first annulus, the second annulus and the second halogen discharge pipe 29 is closed, that is, the valve two 5, the valve five 24 and the valve four 21 shown in Fig. 1 are closed.

[0066] In this step, the volume of hydrogen 16 flowing out of the hydrogen buffer well 25 is recorded by the flowmeter three 23, and the volume of hydrogen 16 injected into the hydrogen storage test well 15 is recorded by the flowmeter one 21. In the case that there is no hydrogen leakage in the hydrogen pipeline 17, it is considered that the volume of hydrogen produced from the hydrogen buffer well 25 should be equal to the volume of hydrogen injected into the hydrogen storage test well 15.

[0067] R4, the hydrogen storage test well 15 and the hydrogen buffer well 25 are closed for a predetermined time, and the step R1 is returned until the cycle is repeated for a predetermined number of times;

[0068] The process from the production of hydrogen from the hydrogen storage test well 15 to the injection of hydrogen into the hydrogen buffer well 25, and then to the injection of hydrogen into the hydrogen storage test well again, that is, the process from high pressure to low pressure and then to high pressure, is one injection-production cycle. The verification of the whole salt cavern hydrogen storage verification system requires at least 100 injection-production cycles, and preferably at least 500 injection-production cycles.

[0069] R5, the hydrogen leakage rate of the hydrogen storage test well 15 in each test cycle is counted, and if the requirement is met, the hydrogen storage test well 15 is put into use in the salt cavern hydrogen storage library.

[0070] Specifically, whether the hydrogen storage test well 15 can be put into use in the salt cavern hydrogen storage library is judged by the hydrogen leakage volume and the leakage rate of the hydrogen storage test well 15. The hydrogen leakage volume and the leakage rate of the hydrogen storage test well 15 are obtained by flowmeter data analysis. For example, the pressure range of the hydrogen storage test well 15 in this test is 11-12 MPa. Before the first injection-production cycle starts, the pressure gauge one 3 of the wellhead Christmas tree 2 shows 12 MPa. The pressure of the hydrogen storage test well 15 will decrease after the hydrogen is injected into the hydrogen buffer well 25, and the value of the pressure gauge one 3 will decrease. When the pressure decreases to 11 MPa, the hydrogen injection is stopped, and the volume of hydrogen produced from the hydrogen storage test well 15 is recorded by the flowmeter one 4 as Am 3 The volume of hydrogen injected into the hydrogen buffer well is also recorded by the flowmeter three 23 as Am 3 After a period of time, the hydrogen is injected back into the hydrogen storage test well by injecting brine into the hydrogen buffer well 25, and the hydrogen is completely produced from the hydrogen buffer well. The volume of hydrogen produced from the hydrogen buffer well 25 is recorded by the flowmeter three 23 as Bm 3The volume of hydrogen injected into the hydrogen storage test well 15 is recorded by the flow meter 4 as Bm 3 Because hydrogen leakage can occur during the storage of hydrogen in the hydrogen buffer well 25, the volume of hydrogen produced from the hydrogen buffer well 25 should be less than or equal to the volume of hydrogen injected. The leakage of hydrogen in the hydrogen buffer well 25 is the difference between the volume of hydrogen injected and the volume of hydrogen produced.

[0071] Before the start of the second injection-production cycle, the pressure gauge 3 of the hydrogen storage test well 15 is less than or equal to 12 MPa due to the possibility of hydrogen leakage. During the second injection-production cycle, the pressure of the hydrogen storage test well 15 decreases as gas is produced and injected into the hydrogen buffer well 25. When the pressure gauge 3 drops to 11 MPa, gas production is stopped, and the volume of hydrogen produced from the hydrogen storage test well is recorded by the flow meter 4 as Cm 3 The volume of hydrogen injected into the hydrogen buffer well is also Cm 3 The leakage of the entire system is the difference between the volume of hydrogen injected in the last cycle and the volume of hydrogen produced in this cycle. The leakage of the hydrogen buffer well 25 is A-B. The leakage of the hydrogen storage test well 15 is A-C-(A-B). The daily leakage rate is calculated based on the time difference between the two injection-production cycles. The hydrogen leakage rate of the hydrogen storage test well should be less than 50 cubic meters per day. It should be noted that a hydrogen leakage rate of less than 50 cubic meters per day is a standard in most cases, and this standard can be adjusted according to actual conditions or needs.

[0072] If the hydrogen storage test well 15 passes the seal test, the hydrogen pipeline 17 and the compressor 18 between the two wells are removed, and the first brine discharge pipe 13 of the hydrogen storage test well 15 is pulled out under pressure and used in the salt cavern hydrogen storage library, as shown in Figure 4.

[0073] If the hydrogen storage test well 15 fails the seal test, the hydrogen pipeline 17 and the compressor 18 between the two wells are removed, and hydrogen is discharged through the first annular space of the first brine discharge pipe 13 of the hydrogen storage test well 15, and then discharged from the first injection-production channel of the wellhead gas production tree 2. The hydrogen in the hydrogen storage test well 15 is completely discharged, and then natural gas or compressed air is injected into the hydrogen storage test salt cavern through the first injection-production channel of the wellhead gas production tree 2 to completely discharge the brine. The first brine discharge pipe 13 is pulled out under pressure and used in the salt cavern compressed air energy storage power station or the salt cavern natural gas storage library.

[0074] With the above ideal embodiments according to the present application as the inspiration, through the above description, relevant staff can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A salt cavern hydrogen storage verification system, characterized in that, it comprises: a hydrogen storage test well (15) whose wellbore extends into a gas injection and production pipe (12), the gas injection and production pipe (12) extends into a first brine discharge pipe (13), the lower end of the first brine discharge pipe (13) extends into the bottom of the salt cavern of the hydrogen storage test well (15), and a first annulus is formed between the gas injection and production pipe (12) and the first brine discharge pipe (13); a hydrogen buffer well (25) whose wellbore extends into a second brine discharge pipe (29), the lower end of the second brine discharge pipe (29) extends into the bottom of the salt cavern of the hydrogen buffer well (25), and a second annulus is formed between the wellbore of the hydrogen buffer well (25) and the second brine discharge pipe (29); a hydrogen delivery assembly comprising a hydrogen pipeline (17) and a compressor (18) connected in series to the hydrogen pipeline (17), and the two ends of the gas injection and production pipe (12) are connected to the openings of the first annulus and the second annulus respectively.

2. The salt cavern hydrogen storage verification system according to claim 1, characterized in that, the distance between the salt cavern of the hydrogen storage test well (15) and the salt cavern of the hydrogen buffer well (25) is not less than the sum of the maximum diameters of the two salt caverns.

3. The salt cavern hydrogen storage verification system according to claim 1, characterized in that, a valve one (1) is arranged at the opening of the first brine discharge pipe (13), a pressure gauge one (3), a valve two (5) and a flow meter one (4) are arranged at the opening of the first annulus, a third annulus is formed between the wellbore of the hydrogen storage test well (15) and the gas injection and production pipe (12), and a pressure gauge two (6) and a valve three (7) are arranged at the opening of the third annulus; a valve four (21) and a flow meter two (19) are arranged at the opening of the second brine discharge pipe (29), and a pressure gauge three (22), a valve five (24) and a flow meter three (23) are arranged at the opening of the second annulus.

4. The salt cavern hydrogen storage verification system according to claim 1, characterized in that, the wellbores of the hydrogen storage test well (15) and the hydrogen buffer well (25) are each provided with a conductor pipe (8), a surface casing (9) and a production casing (10); wherein, the conductor pipe (8) is cemented with the formation by cementing; the surface casing (9) is arranged in the conductor pipe (8) and is cemented with the conductor pipe (8) and the formation by cementing, the lower end of the surface casing (9) extends downward beyond the conductor pipe (8) and does not extend into the rock salt layer; the production casing (10) is arranged in the surface casing (9) and is cemented with the surface casing (9) and the formation by cementing, the lower end of the production casing (10) extends downward beyond the surface casing (9) and extends into the rock salt layer.

5. The salt cavern hydrogen storage verification system according to claim 4, characterized in that, it further comprises a wellhead gas production tree (2) and a wellhead gas injection and brine production tree (20); wherein, The wellhead gas injection and halogen extraction tree (2) is provided with a first gas injection and extraction channel, a first halogen discharge channel and a monitoring channel, the first gas injection and extraction channel is connected with the gas injection and extraction pipe (12); the first halogen discharge channel is connected with the first halogen discharge pipe (13), and the monitoring channel is connected with the production casing (10) of the hydrogen storage test well (15); The wellhead gas injection and halogen extraction tree (20) is provided with a second gas injection and extraction channel and a second halogen discharge channel, the second gas injection and extraction channel is connected with the production casing (10) of the hydrogen buffer well (25), and the second halogen discharge channel is connected with the second halogen discharge pipe (29).

6. A construction method of the salt cavern hydrogen storage verification system according to any one of claims 1-5, characterized in that, The method comprises: S1, selecting two salt caverns with completed cavities as a hydrogen storage test salt cavern (27) and a hydrogen buffer salt cavern (28) respectively; S2, performing first gas tightness detection on the two salt caverns, and after passing the detection, reforming the two salt caverns to form a hydrogen storage test well (15) and a hydrogen buffer well (25); S3, performing second gas tightness detection on the hydrogen storage test well (15) and the hydrogen buffer well (25), and after passing the detection, injecting hydrogen (16) into the gas injection and extraction pipe (12) of the hydrogen storage test well (15) and discharging brine (26) in the hydrogen storage test well (15); S4, after the brine (26) in the hydrogen storage test well (15) is discharged, continue to inject hydrogen (16) until the pressure rises to the upper limit of the test pressure, connect the first annulus of the hydrogen storage test well (15) and the second annulus of the hydrogen buffer well (25) through a hydrogen pipeline (17), and install a compressor (18).

7. The construction method of the salt cavern hydrogen storage verification system according to claim 6, characterized in that, In step S1, the peak regulation capacity of the hydrogen storage test salt cavern (27) in the test pressure range is not greater than the maximum gas storage capacity of the hydrogen buffer salt cavern (28); In steps S2 and S3, when performing the gas tightness detection, first perform the gas tightness detection with nitrogen, and then perform the gas tightness detection with hydrogen (16) after passing the detection with nitrogen.

8. A verification method of the salt cavern hydrogen storage verification system according to any one of claims 1-5, characterized in that, The method comprises: R1, opening the openings of the first annulus, the second annulus and the second halogen discharge pipe (29), and allowing hydrogen (16) to flow from the hydrogen storage test well (15) to the hydrogen buffer well (25) through the hydrogen pipeline (17), and allowing the brine (26) in the hydrogen buffer well (25) to flow out through the second halogen discharge pipe (29); R2, when the pressure of the hydrogen storage test well (15) drops to the lower limit of the test pressure, closing the openings of the first annulus, the second annulus and the second halogen discharge pipe (29), and recording the volume of hydrogen (16) flowing out of the hydrogen storage test well (15) and the volume of hydrogen (16) injected into the hydrogen buffer well (25); R3, the hydrogen storage test well (15) and the hydrogen buffer well (25) are closed for a predetermined time, then the openings of the first annulus, the second annulus and the second brine discharge pipe (29) are opened, brine (26) is injected into the hydrogen buffer well (25) through the second brine discharge pipe (29), the hydrogen (16) in the hydrogen buffer well (25) flows to the hydrogen storage test well (15) through the hydrogen pipeline (17), after the hydrogen (16) in the hydrogen buffer well (25) is completely produced, the openings of the first annulus, the second annulus and the second brine discharge pipe (29) are closed, and the volume of the hydrogen (16) flowing out of the hydrogen buffer well (25) and the volume of the hydrogen (16) injected into the hydrogen storage test well (15) are recorded; R4, the hydrogen storage test well (15) and the hydrogen buffer well (25) are closed for a predetermined time, then return to step R1 until the cycle is completed for a predetermined number of times; R5, the hydrogen leakage rate of the hydrogen storage test well (15) in each test cycle is counted, and if the requirement is met, the hydrogen storage test well (15) is put into use in the salt cavern hydrogen storage library.

9. The verification method of the salt cavern hydrogen storage verification system according to claim 8, characterized in that, In step S1, after the openings of the first annulus, the second annulus and the second brine discharge pipe (29) are opened, the hydrogen (16) in the hydrogen storage test well (15) flows to the hydrogen buffer well (25) through the hydrogen pipeline (17) under the action of the pressure difference, if the pressure of the hydrogen storage test well (15) does not reach the lower limit of the test pressure when reaching the balance, the compressor (18) is started to pressurize until the pressure of the hydrogen storage test well (15) reaches the lower limit of the test pressure.

Images