Salt cavern compressed air energy storage reservoir stability grade evaluation method and system

Abstract

The invention belongs to the technical field of compressed air energy storage, and discloses a salt cavern compressed air energy storage reservoir stability grade evaluation method and system, and the method comprises the steps: obtaining salt rock physical and mechanical parameters, stratum structure parameters and salt cavern internal structure parameters; selecting a stability evaluation index of the salt-cavern compressed air energy storage library; establishing a three-dimensional geomechanical model of the salt cavern energy storage library and performing simulation calculation; constructing an evaluation model; determining an index weight value of the stability of the salt-cavern compressed air energy storage library; calculating an evaluation grade; and adjusting and optimizing operation parameters of the salt cavern energy storage bank. According to the method, by providing a systematic quantitative analysis process and a unified evaluation index system, the accuracy and reliability of stability evaluation of the salt-cavern compressed air energy storage library are remarkably improved, and an important technical support is provided for development and application of a salt-cavern compressed air energy storage technology. Important technical support is provided for development and application of a salt cavern compressed air energy storage technology, and commercialization and large-scale development of the technology can be promoted.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of compressed air energy storage, and in particular relates to a stability grade evaluation method and system for a salt cavern compressed air energy storage reservoir. Background Art

[0002] The caverns formed after the mining of salt rock have extremely low permeability and porosity, good plasticity and self-healing characteristics, and are considered to be the most suitable geological structures for compressed air energy storage. Salt cavern compressed air energy storage power stations have the characteristics of high injection and production frequency, but with the alternation of high and low pressures inside the salt cavern cavity during the injection and production of gas, the stress state on the cavity wall is constantly changing, resulting in the near-field surrounding rock being affected by unbalanced forces. Under long-term action, the salt cavern will become unstable due to creep, settlement, spalling and leakage, leading to the abandonment of the salt cavern.

[0003] For example, the constant-pressure compressed air energy storage method, system and related equipment disclosed in publication number CN116357552A discloses a constant-pressure compressed air energy storage method, system and related equipment; through the constant-pressure compressed air energy storage system, the sediment voids in high-impurity salt rock formations can be used to store compressed air.

[0004] For example, publication number CN216743811U discloses a water-stabilized pressure gas storage system, which solves the technical problem of poor pressure stability in the existing compressed air energy storage process, and provides a water-stabilized pressure gas storage system, including a controller, an air storage tank, a sealing assembly, and a sliding water pool design, using an air storage tank for energy storage.

[0005] For example, the model test device and method for simulating the deformation and destruction of the surrounding rock of a compressed air energy storage reservoir disclosed in publication number CN116519489A includes: a geophysical model module, a gas storage reservoir simulation module and a process monitoring module. The gas receiving module in the gas storage reservoir simulation module is arranged inside the geophysical model module, and the gas supply module is arranged outside the geophysical model module. This realizes the simulation of the deformation and destruction effect of the cyclic load on the surrounding rock of the compressed air energy storage reservoir during the filling and degassing process under indoor conditions, as well as the failure law of the surrounding rock of the gas storage reservoir under extreme conditions.

[0006] The above-mentioned related invention patents are all related to ensuring the safe operation of compressed air energy storage, but there are currently few related inventions for salt cavern compressed air energy storage, especially the lack of stability grade evaluation methods. Since the physical and mechanical properties of salt rock in salt cavern energy storage are sensitive to changes in temperature and stress, salt rock damage shows a strong scale effect. Therefore, how to accurately evaluate the stability of salt cavern compressed air energy storage is full of challenges. At present, the stability evaluation of salt cavern compressed air energy storage mainly has the following technical difficulties:

[0007] Lack of systematic quantitative analysis process and steps: In the stability evaluation process of salt cavern compressed air energy storage, there is a lack of a systematic, quantitative analysis process and steps, which makes it difficult to standardize and normalize the evaluation work, affecting the accuracy and reliability of the evaluation results.

[0008] Lack of a unified stability rating evaluation index system: Currently, there is no unified evaluation index system for the stability evaluation of salt cavern compressed air energy storage facilities. This results in different researchers or institutions using different evaluation methods and indicators, making it difficult to conduct horizontal comparisons and evaluations.

[0009] Sensitivity to physical and mechanical properties of salt rock: The physical and mechanical properties of salt rock in salt cavern energy storage are sensitive to changes in temperature and stress. Salt rock damage shows a strong scale effect, which increases the complexity and difficulty of stability evaluation.

[0010] Leakage problem: Salt cavern underground gas storage is generally built in lake-phase sedimentary salt rock rich in mud interlayers. The porosity and permeability of mud interlayers are greater than those of salt rock, so their permeability plays a controlling role in the airtightness of the gas storage. The sedimentary characteristics of interlayers are generally distributed horizontally, which requires the establishment of a theoretical model for leakage analysis of multi-interlayer salt cavern gas storage, and the calculation of compressed air leakage based on actual operating parameters to evaluate the influencing factors and changing laws of gas leakage range and leakage amount.

[0011] Adaptability to environmental changes: Since the physical and mechanical properties of salt rock are sensitive to environmental changes, such as temperature and stress changes, it is necessary to consider the impact of these environmental factors on the stability of salt caverns during stability evaluation. Summary of the invention

[0012] In view of the problems existing in the prior art, the present invention provides a method and system for evaluating the stability level of a salt cavern compressed air energy storage reservoir.

[0013] The present invention is implemented as follows: a method for evaluating the stability level of a salt cavern compressed air energy storage reservoir, the method comprising:

[0014] S1: Obtain the physical and mechanical parameters of salt rock, stratum structure parameters and internal structural parameters of salt caverns;

[0015] S2: Select the stability evaluation index of salt cavern compressed air energy storage;

[0016] S3: Establishment and simulation of three-dimensional geomechanical model of salt cavern energy storage;

[0017] S4: Construct an evaluation model and establish a stability rating evaluation table for salt cavern compressed air energy storage reservoirs; the stability evaluation of salt cavern compressed air energy storage reservoirs belongs to multi-objective decision-making. First, the hierarchical analysis method is used to comprehensively evaluate the factors affecting the stability of the salt caverns, and then a comprehensive evaluation model for the stability of salt cavern compressed air energy storage reservoirs is constructed through a multi-factor comprehensive evaluation method;

[0018] S5. Determine the weight value of the indicator of the stability of the salt cavern compressed air energy storage reservoir; construct a judgment matrix for the evaluation indicators at different levels in the evaluation system, calculate the weight value of the evaluation indicator by arithmetic mean method and perform consistency test to ensure that all random indicators are less than 0.1. If the condition that all random indicators are less than 0.1 is not met, it is necessary to check or update the scale value of the judgment matrix to make the condition meet;

[0019] S6, calculating the evaluation grade, according to the stability evaluation index value of the salt cavern compressed air energy storage reservoir obtained in S2, according to the stability grade evaluation table of the salt cavern compressed air energy storage reservoir established in S4, obtaining the evaluation index score mi, according to the comprehensive evaluation model of the stability of the salt cavern compressed air energy storage reservoir established in S4, obtaining the comprehensive score M of the salt cavern energy storage reservoir, and then determining the stability grade of the salt cavern compressed air energy storage reservoir according to the comprehensive score M;

[0020] S7. Adjust and optimize the operating parameters of the salt cavern energy storage reservoir; obtain the corresponding values ​​of the stability indicators based on the numerical simulation calculations in S6 and draw a cloud map, adjust and optimize the operating parameters of the salt cavern energy storage reservoir based on the evaluation level, and propose reasonable preventive measures.

[0021] Furthermore, S1 specifically includes: conducting a small-scale hydraulic fracturing experiment at the target layer for building the salt cavern energy storage reservoir to determine the ground stress value and its gradient in the salt rock formation; using three-dimensional seismic exploration technology to determine the geological structure parameters of the salt cavern energy storage reservoir construction area; using three-dimensional sonar cavity measurement technology and temperature sensors to determine the internal structure parameters of the salt cavern.

[0022] Furthermore, the three-dimensional seismic exploration technology is used to determine the geological structural parameters of the salt cavern energy storage reservoir construction area, including: salt rock top surface, salt rock bottom surface, salt rock thickness distribution, sedimentary phase belt distribution, and formation fault distribution; through drilling and coring operations, formation core samples of the reservoir construction area are obtained to conduct density, composition, permeability, porosity, uniaxial compressive strength, tensile strength, internal friction angle, cohesion, steady-state creep rate, shear strength, and breakthrough pressure tests;

[0023] The three-dimensional sonar cavity measurement technology and temperature sensor are used to determine the internal structural parameters of the salt cavern, including: the burial depth of the top of the salt cavern, the burial depth of the bottom of the salt cavern, the height of the salt cavern, the maximum radius of the salt cavern, and the temperature of the top and bottom of the salt cavern.

[0024] Furthermore, S2 specifically includes: considering that salt rock has typical characteristics such as creep deformation and damage self-repair, deformation, plastic zone, volume shrinkage rate, shear safety factor, and equivalent strain are selected as salt cavern cavity stability evaluation indicators, and completion string axial strain and compressed air seepage range are selected as string safety evaluation indicators.

[0025] Furthermore, S3 specifically includes: establishing a three-dimensional geomechanical model and boundary conditions based on the physical and mechanical parameters of the salt rock, the formation structure parameters and the internal structural parameters of the salt cavern obtained by S3. The bottom of the model is subject to fixed constraints, the four vertical surfaces are subject to horizontal constraints, and the top is subject to overlying formation pressure; numerical simulation is used to calculate the stability index value and draw a cloud map.

[0026] Furthermore, the analytic hierarchy process is as shown in formula (1) and (2), and the multi-factor comprehensive evaluation method is as shown in formula (3);

[0027]

[0028]

[0029] Where: P is the judgment matrix; a ij is the scale value of the comparison of the importance of two factors; CI is the consistency index of the judgment matrix; CR is the consistency test index; RI is the random consistency index, and the RI value is obtained by looking up the RI table; n is the order of the judgment matrix; λ max is the maximum eigenvalue; ω i is the weight value of each evaluation index.

[0030] Comparison between two indicators: the quantitative value of equal importance is 1, the quantitative value of slightly important is 3, the quantitative value of strong importance is 5, the quantitative value of extremely important is 7, the quantitative value of extremely important is 9, and the intermediate value of two adjacent judgments is 2, 4, 6, 8, and the scale value of the comparison of the importance of two factors is a ij =1 / a ji ;

[0031] A comprehensive evaluation model for the stability of salt cavern compressed air energy storage is constructed through a multi-factor comprehensive evaluation method.

[0032]

[0033] Where: m i is the quantitative value of each evaluation index; M is the comprehensive score of stability;

[0034] Another object of the present invention is to provide a salt cavern compressed air energy storage reservoir stability grade evaluation system based on the salt cavern compressed air energy storage reservoir stability grade evaluation method, the system specifically comprising:

[0035] Parameter acquisition module, which acquires physical and mechanical parameters of salt rock, formation structure parameters and internal structural parameters of salt caverns;

[0036] Index selection module, selects the stability evaluation index of salt cavern compressed air energy storage;

[0037] The model building and calculation module is connected with the parameter acquisition module to build the three-dimensional geomechanical model of the salt cavern energy storage reservoir and perform simulation calculations;

[0038] Model building module, building evaluation model and establishing stability grade evaluation table of salt cavern compressed air energy storage;

[0039] An indicator weight value determination module is used to determine the indicator weight value of the stability of the salt cavern compressed air energy storage reservoir;

[0040] The grade evaluation module is connected with the indicator selection module and the model construction module to calculate the evaluation grade;

[0041] The parameter optimization module is connected with the grade evaluation module to adjust and optimize the operating parameters of the salt cavern energy storage reservoir.

[0042] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the salt cavern compressed air energy storage reservoir stability level evaluation method.

[0043] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to perform the steps of the salt cavern compressed air energy storage reservoir stability level evaluation method.

[0044] Another object of the present invention is to provide an information data processing terminal, which is used to implement the salt cavern compressed air energy storage reservoir stability grade evaluation system.

[0045] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0046] First, the present invention can improve the regulation capacity of the power grid: the salt cavern compressed air energy storage technology can realize peak shaving and valley filling of the power grid, that is, storing energy when the power demand is low and releasing energy to generate electricity during peak hours, effectively improving the regulation capacity of the power grid.

[0047] The present invention can promote the consumption of new energy: the technology can effectively solve the problem of difficulty in connecting clean energy such as solar energy and wind energy to the grid, significantly improve energy utilization, and play an important role in promoting the consumption of new energy.

[0048] This invention can realize large-scale clean energy storage: Salt cavern compressed air energy storage technology is a large-scale, long-term physical energy storage method that can realize large-scale clean energy storage of electricity. It is of great significance for building a new power system and achieving the goals of "carbon peak and carbon neutrality".

[0049] The present invention can improve the sustainable development of energy and electricity: through the salt cavern compressed air energy storage technology, the "time shift" of electric energy can be realized in the power system, that is, the effective allocation and utilization of electric energy in different time periods, which is of great significance to ensuring the sustainable development of energy and electricity.

[0050] The present invention can optimize the structure of electricity supply and demand: this technology can significantly improve the temporal and spatial structure of power generation and power consumption, and achieve optimal configuration of electricity supply and demand.

[0051] Second, the invention significantly improves the accuracy and reliability of the stability evaluation of salt cavern compressed air energy storage reservoirs by providing a systematic quantitative analysis process and a unified evaluation index system, providing important technical support for the development and application of salt cavern compressed air energy storage technology. It provides important technical support for the development and application of salt cavern compressed air energy storage technology and helps promote the commercialization and large-scale development of this technology.

[0052] Third, as auxiliary evidence of the inventiveness of the claims of the present invention, it is also reflected in the following important aspects:

[0053] (1) The expected benefits and commercial value of the technical solution of the present invention after transformation are:

[0054] Reduce project risks and costs. The technical solution of the present invention can identify potential safety hazards of salt cavern compressed air energy storage in advance, so as to take effective prevention and reinforcement measures to reduce the probability of accidents such as salt cavern instability; based on the scientific and accurate stability evaluation results, the design and construction of salt cavern energy storage can be optimized to avoid large-scale design changes and engineering rework due to stability problems during the construction process, saving time and cost. Improve the performance and efficiency of the energy storage system. Through an effective stability grade evaluation method, it can ensure that the salt cavern energy storage maintains good sealing and mechanical stability during the long-term energy storage and release cycle, thereby ensuring the storage quality and pressure stability of compressed air, improving the performance of the energy storage system, reducing the energy loss during the storage and release of compressed air, and obtaining higher energy conversion efficiency, thereby increasing the benefits of the project. Extend the service life of the salt cavern compressed air energy storage. The technical solution of the present invention can timely discover potential stability problems of the salt cavern compressed air energy storage, slow down the creep and deformation process of the salt cavern, extend the service life of the salt cavern compressed air energy storage, reduce the depreciation cost of the project, and improve the value of the project assets and the return on investment.

[0055] (2) The technical solution of the present invention fills the technical gap in the industry at home and abroad:

[0056] The technical solution of the present invention fills a technical gap, that is, there is no unified evaluation index system for the stability evaluation of salt cavern compressed air energy storage. This situation causes different researchers and institutions to use different evaluation methods and indicators when conducting evaluations, which makes it difficult to conduct horizontal comparisons and quantitative evaluations.

[0057] (3) The technical solution of the present invention solves the technical problems that people have been eager to solve but have never been able to solve successfully:

[0058] The technical solution of the present invention solves the following technical problems in the stability evaluation process of salt cavern compressed air energy storage:

[0059] Lack of systematic quantitative analysis process and steps: In the stability evaluation process of salt cavern compressed air energy storage, there is a lack of a systematic, quantitative analysis process and steps, which makes it difficult to standardize and normalize the evaluation work, affecting the accuracy and reliability of the evaluation results.

[0060] Lack of a unified stability rating evaluation index system: Currently, there is no unified evaluation index system for the stability evaluation of salt cavern compressed air energy storage facilities. This results in different researchers or institutions using different evaluation methods and indicators, making it difficult to conduct horizontal comparisons and evaluations.

[0061] Sensitivity to physical and mechanical properties of salt rock: The physical and mechanical properties of salt rock in salt cavern energy storage are sensitive to changes in temperature and stress. Salt rock damage shows a strong scale effect, which increases the complexity and difficulty of stability evaluation.

[0062] Leakage problem: Salt cavern underground gas storage is generally built in lake-phase sedimentary salt rock rich in mud interlayers. The porosity and permeability of mud interlayers are greater than those of salt rock, so their permeability plays a controlling role in the airtightness of the gas storage. The sedimentary characteristics of interlayers are generally distributed horizontally, which requires the establishment of a theoretical model for leakage analysis of multi-interlayer salt cavern gas storage, and the calculation of compressed air leakage based on actual operating parameters to evaluate the influencing factors and changing laws of gas leakage range and leakage amount.

[0063] Adaptability to environmental changes: Since the physical and mechanical properties of salt rock are sensitive to environmental changes, such as temperature and stress changes, it is necessary to consider the impact of these environmental factors on the stability of salt caverns during stability evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 It is a flow chart of a stability grade evaluation method for a salt cavern compressed air energy storage reservoir provided by an embodiment of the present invention;

[0065] Figure 2 It is a schematic diagram of the steps of the method for evaluating the stability level of a salt cavern compressed air energy storage reservoir provided by an embodiment of the present invention;

[0066] Figure 3 It is a schematic diagram of the structure of the salt cavern compressed air energy storage reservoir provided by an embodiment of the present invention;

[0067] Figure 4 It is a structural diagram of a stability grade evaluation system for a salt cavern compressed air energy storage reservoir provided by an embodiment of the present invention;

[0068] Figure 5 It is a diagram of a stability evaluation system of a salt cavern compressed air energy storage reservoir provided by an embodiment of the present invention;

[0069] Figure 6 It is a bar chart of the weights of the stability grade evaluation indexes of the salt cavern compressed air energy storage provided by the embodiment of the present invention;

[0070] In the figure: 1. Compressed air; 2. Brine; 3. Ground; 4. Completion casing; 5. Inner brine drainage pipe; 6. Salt rock; 7. Protective fluid; 8. Packer; 9. Outer brine drainage pipe; 10. Energy storage cavity; 11. Interlayer; 12. Insoluble sediment; 13. Final gas-brine interface. DETAILED DESCRIPTION

[0071] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0072] like Figure 1 , 2 As shown, an embodiment of the present invention provides a method for evaluating the stability level of a salt cavern compressed air energy storage reservoir, the method comprising:

[0073] S1: Obtain the physical and mechanical parameters of salt rock, stratum structure parameters and internal structural parameters of salt caverns;

[0074] S2: Select the stability evaluation index of salt cavern compressed air energy storage;

[0075] S3: Establishment and simulation of three-dimensional geomechanical model of salt cavern energy storage;

[0076] S4: Construct an evaluation model and establish a stability rating evaluation table for salt cavern compressed air energy storage reservoirs; the stability evaluation of salt cavern compressed air energy storage reservoirs belongs to multi-objective decision-making. First, the hierarchical analysis method is used to comprehensively evaluate the factors affecting the stability of the salt caverns, and then a comprehensive evaluation model for the stability of salt cavern compressed air energy storage reservoirs is constructed through a multi-factor comprehensive evaluation method;

[0077] The factors affecting the stability of salt cavern compressed air energy storage reservoirs are classified, and the stability evaluation standard of salt cavern compressed air energy storage reservoirs is first established as shown in Table 1.

[0078] Table 1 Stability evaluation criteria for salt cavern compressed air energy storage

[0079]

[0080]

[0081] Then, a stability evaluation table for salt cavern compressed air energy storage is established in the form of interval scores, as shown in Table 2. The table includes four levels: good, relatively good, medium, and poor, and the score intervals are (9, 10], (7, 9], (6, 7], and [0, 6], respectively.

[0082] Table 2 Evaluation table of stability level of salt cavern compressed air energy storage

[0083]

[0084] S5. Determine the weight value of the indicator of the stability of the salt cavern compressed air energy storage reservoir; construct a judgment matrix for the evaluation indicators at different levels in the evaluation system, calculate the weight value of the evaluation indicator by arithmetic mean method and perform consistency test to ensure that all random indicators are less than 0.1. If the condition that all random indicators are less than 0.1 is not met, it is necessary to check or update the scale value of the judgment matrix to make the condition meet;

[0085] S6, calculating the evaluation grade, according to the stability evaluation index value of the salt cavern compressed air energy storage reservoir obtained in S2, according to the stability grade evaluation table of the salt cavern compressed air energy storage reservoir established in S4, obtaining the evaluation index score mi, according to the comprehensive evaluation model of the stability of the salt cavern compressed air energy storage reservoir established in S4, obtaining the comprehensive score M of the salt cavern energy storage reservoir, and then determining the stability grade of the salt cavern compressed air energy storage reservoir according to the comprehensive score M;

[0086] S7. Adjust and optimize the operating parameters of the salt cavern energy storage reservoir; obtain the corresponding values ​​of the stability indicators based on the numerical simulation calculations in S6 and draw a cloud map, adjust and optimize the operating parameters of the salt cavern energy storage reservoir based on the evaluation level, and propose reasonable preventive measures.

[0087] The S1 specifically includes: conducting a small hydraulic fracturing experiment at the target layer for the construction of the salt cavern energy storage reservoir to determine the ground stress value and its gradient in the salt rock formation; using three-dimensional seismic exploration technology to determine the geological structure parameters of the construction area of ​​the salt cavern energy storage reservoir; using three-dimensional sonar cavity measurement technology and temperature sensors to determine the internal structure parameters of the salt cavern.

[0088] The three-dimensional seismic exploration technology is used to determine the geological structural parameters of the salt cavern energy storage reservoir construction area, including: salt rock top surface, salt rock bottom surface, salt rock thickness distribution, sedimentary phase belt distribution, and formation fault distribution; through drilling and coring operations, formation core samples of the reservoir construction area are obtained to conduct density, composition, permeability, porosity, uniaxial compressive strength, tensile strength, internal friction angle, cohesion, steady-state creep rate, shear strength, and breakthrough pressure tests;

[0089] The three-dimensional sonar cavity measurement technology and temperature sensor are used to determine the internal structural parameters of the salt cavern, including: the burial depth of the top of the salt cavern, the burial depth of the bottom of the salt cavern, the height of the salt cavern, the maximum radius of the salt cavern, and the temperature of the top and bottom of the salt cavern.

[0090] The S2 specifically includes: considering that salt rock has typical characteristics such as creep deformation and damage self-repair, deformation, plastic zone, volume shrinkage rate, shear safety factor, and equivalent strain are selected as salt cavern cavity stability evaluation indicators, and completion string axial strain and compressed air seepage range are selected as string safety evaluation indicators.

[0091] S3 specifically includes: establishing a three-dimensional geomechanical model and boundary conditions based on the physical and mechanical parameters of the salt rock, the formation structure parameters and the internal structural parameters of the salt cavern obtained by S3. The bottom of the model is subject to fixed constraints, the four vertical surfaces are subject to horizontal constraints, and the top is subject to overlying formation pressure; numerical simulation is used to calculate the stability index value and draw a cloud map.

[0092] The analytic hierarchy process is as shown in formula (1) and (2), and the multi-factor comprehensive evaluation method is as shown in formula (3);

[0093]

[0094]

[0095] Where: P is the judgment matrix; a ij is the scale value of the comparison of the importance of two factors; CI is the consistency index of the judgment matrix; CR is the consistency test index; RI is the random consistency index, and the RI value is obtained by looking up the RI table; n is the order of the judgment matrix; λ max is the maximum eigenvalue; ω i is the weight value of each evaluation index.

[0096] Comparison between two indicators: the quantitative value of equal importance is 1, the quantitative value of slightly important is 3, the quantitative value of strong importance is 5, the quantitative value of extremely important is 7, the quantitative value of extremely important is 9, and the intermediate value of two adjacent judgments is 2, 4, 6, 8, and the scale value of the comparison of the importance of two factors is a ij =1 / a ji ;

[0097] A comprehensive evaluation model for the stability of salt cavern compressed air energy storage is constructed through a multi-factor comprehensive evaluation method.

[0098]

[0099] Where: m i is the quantitative value of each evaluation index; M is the comprehensive stability score.

[0100] Table 3 Stability index score table of salt cavern compressed air energy storage in X area

[0101]

[0102] The final calculation result has a comprehensive score of M=8.317557. According to the stability grade evaluation table of salt cavern compressed air energy storage, the stability grade of salt cavern compressed air energy storage in area X is good, which is more suitable for compressed air energy storage. However, the monitoring of the resistance of salt cavern surrounding rocks must be strengthened during the operation period.

[0103] The embodiment of the present invention provides a salt cavern compressed air energy storage reservoir stability grade evaluation system based on the salt cavern compressed air energy storage reservoir stability grade evaluation method, and the system specifically includes:

[0104] Parameter acquisition module, which acquires physical and mechanical parameters of salt rock, formation structure parameters and internal structural parameters of salt caverns;

[0105] Index selection module, selects the stability evaluation index of salt cavern compressed air energy storage;

[0106] The model building and calculation module is connected with the parameter acquisition module to build the three-dimensional geomechanical model of the salt cavern energy storage reservoir and perform simulation calculations;

[0107] Model building module, building evaluation model and establishing stability grade evaluation table of salt cavern compressed air energy storage;

[0108] An indicator weight value determination module is connected to the indicator selection module to determine the indicator weight value of the stability of the salt cavern compressed air energy storage reservoir;

[0109] The grade evaluation module is connected with the indicator selection module and the model construction module to calculate the evaluation grade;

[0110] The parameter optimization module is connected with the grade evaluation module to adjust and optimize the operating parameters of the salt cavern energy storage reservoir.

[0111] An embodiment of the present invention provides a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the salt cavern compressed air energy storage reservoir stability level evaluation method.

[0112] An embodiment of the present invention provides a computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the salt cavern compressed air energy storage reservoir stability grade evaluation method.

[0113] An embodiment of the present invention provides an information data processing terminal, which is used to implement the salt cavern compressed air energy storage reservoir stability grade evaluation system.

[0114] like Figure 3 As shown, compressed air 1 enters through the inlet at the top of the energy storage cavity 10, driving the protective fluid 7 downward along the completion casing 4 and the brine discharge outer pipe 9 into the brine discharge inner pipe 5 of the salt rock layer 6. The protective fluid forms a pressure isolation layer in the cavity, effectively preventing the brine 2 from directly contacting the gas, ensuring the air tightness of the cavity and the stable discharge of the brine.

[0115] The packer 8 is arranged in the completion casing 4 to separate different pressure areas and avoid the mixing and interference of gas and brine. The brine discharge inner pipe 5 and the brine discharge outer pipe 9 are isolated from the cavity by the packer, so that the brine can be discharged efficiently from the salt rock layer 6. The brine finally enters the next process through the ground treatment device.

[0116] As the compressed air 1 enters the energy storage chamber 10, the final gas-brine interface 13 in the chamber is pushed downward by the compressed air, gradually discharging the brine 2 from the brine discharge inner pipe 5. At the same time, the insoluble sediment 12 at the bottom of the energy storage chamber is deposited in the interlayer 11, which can be regularly cleaned through a specific discharge port during subsequent maintenance to avoid blockage.

[0117] In the energy storage chamber 10, compressed air 1 enters the chamber as an energy storage medium and forms a stable interface with the protective liquid 7. When the stored energy needs to be released, the compressed air is led out through the gas outlet for external use, while the protective liquid maintains the airtightness and stability of the energy storage chamber through the brine drainage system, ensuring the efficient operation of the system under different working conditions.

[0118] The stability evaluation system of the salt cavern compressed air energy storage reservoir according to the embodiment of the present invention is as follows Figure 5 shown.

[0119] Construct the judgment matrix P for different levels of evaluation indicators, and the results are shown in formulas (4)(5)(6);

[0120] The AB level judgment matrix is:

[0121]

[0122] The salt cavern stability judgment matrix of level B is:

[0123]

[0124] The B-level string safety judgment matrix is:

[0125]

[0126] Furthermore, the arithmetic mean is used to calculate the weight of the evaluation index and perform a consistency test. First, the sum of each column is calculated according to the judgment matrix, and each element of each column is replaced by the sum of the corresponding column to obtain a quantized judgment matrix; then, the sum of each row of the new judgment matrix is ​​calculated and the average is taken, and the average is the weight value ωi of the stability evaluation index of the salt cavern energy storage reservoir; finally, according to the obtained weight value ωi; a consistency test is performed, and the final weight value result is: ωA-B=[0.80000,0.20000], ωB1-C=[0.07792,0.15234,0.10412,0.41042,0.25520], ωB2-C=[0.66670,0.33330], and the consistency test indicators are all less than 0.1. The weight bar graph of the stability grade evaluation index of the salt cavern compressed air energy storage reservoir is drawn as shown in the figure Figure 6 shown.

[0127] Depend on Figure 6 It can be seen that for the stability of the salt cavern cavity, the shear dilatancy safety factor and the equivalent strain account for a relatively high proportion, followed by the plastic zone. For the safety of the tubing, the axial strain of the completion tubing accounts for a relatively high proportion, indicating that in the stability evaluation of the salt cavern compressed air energy storage reservoir, attention should be paid to the effects of ground stress and surrounding rock resistance, which have a great influence on the stability of the salt cavern compressed air energy storage reservoir.

[0128] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. A person of ordinary skill in the art will appreciate that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD, ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0129] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the stability level of a salt cavern compressed air energy storage reservoir, characterized in that: The method includes: S1: Obtain the physical and mechanical parameters of salt rock, stratum structure parameters and internal structural parameters of salt caverns; S2: Select the stability evaluation index of salt cavern compressed air energy storage; S3: Establishment and simulation of three-dimensional geomechanical model of salt cavern energy storage; S4: Construct an evaluation model and establish a stability rating evaluation table for salt cavern compressed air energy storage reservoirs; the stability evaluation of salt cavern compressed air energy storage reservoirs belongs to multi-objective decision-making. First, the hierarchical analysis method is used to comprehensively evaluate the factors affecting the stability of the salt caverns, and then a comprehensive evaluation model for the stability of salt cavern compressed air energy storage reservoirs is constructed through a multi-factor comprehensive evaluation method; S5. Determine the weight value of the indicator of the stability of the salt cavern compressed air energy storage reservoir; construct a judgment matrix for the evaluation indicators at different levels in the evaluation system, calculate the weight value of the evaluation indicator by arithmetic mean method and perform consistency test to ensure that all random indicators are less than 0.

1. If the condition that all random indicators are less than 0.1 is not met, it is necessary to check or update the scale value of the judgment matrix to make the condition meet; S6, calculating the evaluation grade, according to the stability evaluation index value of the salt cavern compressed air energy storage reservoir obtained in S2, according to the stability grade evaluation table of the salt cavern compressed air energy storage reservoir established in S4, obtaining the evaluation index score mi, according to the comprehensive evaluation model of the stability of the salt cavern compressed air energy storage reservoir established in S4, obtaining the comprehensive score M of the salt cavern energy storage reservoir, and then determining the stability grade of the salt cavern compressed air energy storage reservoir according to the comprehensive score M; S7. Adjust and optimize the operating parameters of the salt cavern energy storage reservoir; obtain the corresponding values ​​of the stability indicators based on the numerical simulation calculations in S6 and draw a cloud map, adjust and optimize the operating parameters of the salt cavern energy storage reservoir based on the evaluation level, and propose reasonable preventive measures.

2. The stability grade evaluation method of the salt cavern compressed air energy storage reservoir according to claim 1 is characterized in that: The S1 specifically includes: conducting a small hydraulic fracturing experiment at the target layer for the construction of the salt cavern energy storage reservoir to determine the ground stress value and its gradient in the salt rock formation; using three-dimensional seismic exploration technology to determine the geological structure parameters of the construction area of ​​the salt cavern energy storage reservoir; using three-dimensional sonar cavity measurement technology and temperature sensors to determine the internal structure parameters of the salt cavern.

3. The stability grade evaluation method of the salt cavern compressed air energy storage reservoir according to claim 2 is characterized in that: The three-dimensional seismic exploration technology is used to determine the geological structural parameters of the salt cavern energy storage reservoir construction area, including: salt rock top surface, salt rock bottom surface, salt rock thickness distribution, sedimentary phase belt distribution, and formation fault distribution; through drilling and coring operations, formation core samples of the reservoir construction area are obtained to conduct density, composition, permeability, porosity, uniaxial compressive strength, tensile strength, internal friction angle, cohesion, steady-state creep rate, shear strength, and breakthrough pressure tests; The three-dimensional sonar cavity measurement technology and temperature sensor are used to determine the internal structural parameters of the salt cavern, including: the burial depth of the top of the salt cavern, the burial depth of the bottom of the salt cavern, the height of the salt cavern, the maximum radius of the salt cavern, and the temperature of the top and bottom of the salt cavern.

4. The method for evaluating the stability level of a salt cavern compressed air energy storage reservoir according to claim 1 is characterized in that: The S2 specifically includes: considering that salt rock has typical characteristics such as creep deformation and damage self-repair, deformation, plastic zone, volume shrinkage rate, shear safety factor, and equivalent strain are selected as salt cavern cavity stability evaluation indicators, and completion string axial strain and compressed air seepage range are selected as string safety evaluation indicators.

5. The stability grade evaluation method of salt cavern compressed air energy storage according to claim 1 is characterized in that: S3 specifically includes: establishing a three-dimensional geomechanical model and boundary conditions based on the physical and mechanical parameters of the salt rock, the formation structure parameters and the internal structural parameters of the salt cavern obtained by S3. The bottom of the model is subject to fixed constraints, the four vertical surfaces are subject to horizontal constraints, and the top is subject to overlying formation pressure; numerical simulation is used to calculate the stability index value and draw a cloud map.

6. The stability grade evaluation method of salt cavern compressed air energy storage according to claim 1 is characterized in that: The analytic hierarchy process is as shown in formula (1) and (2), and the multi-factor comprehensive evaluation method is as shown in formula (3); Where: P is the judgment matrix; a ij is the scale value of the comparison of the importance of two factors; CI is the consistency index of the judgment matrix; CR is the consistency test index; RI is the random consistency index, and the RI value is obtained by looking up the RI table; n is the order of the judgment matrix; λ max is the maximum eigenvalue; ω i is the weight value of each evaluation index. Comparison between two indicators: the quantitative value of equal importance is 1, the quantitative value of slightly important is 3, the quantitative value of strong importance is 5, the quantitative value of extremely important is 7, the quantitative value of extremely important is 9, and the intermediate value of two adjacent judgments is 2, 4, 6, 8, and the scale value of the comparison of the importance of two factors is a ij =1 / a ji ; A comprehensive evaluation model for the stability of salt cavern compressed air energy storage is constructed through a multi-factor comprehensive evaluation method. Where: m i is the quantitative value of each evaluation index; M is the comprehensive stability score.

7. A salt cavern compressed air energy storage stability grade evaluation system based on the evaluation method according to any one of claims 1 to 6, characterized in that: The system specifically includes: Parameter acquisition module, which acquires physical and mechanical parameters of salt rock, formation structure parameters and internal structural parameters of salt caverns; Index selection module, selects the stability evaluation index of salt cavern compressed air energy storage; The model building and calculation module is connected with the parameter acquisition module to build the three-dimensional geomechanical model of the salt cavern energy storage reservoir and perform simulation calculations; Model building module, building evaluation model and establishing stability grade evaluation table of salt cavern compressed air energy storage; An indicator weight value determination module is used to determine the indicator weight value of the stability of the salt cavern compressed air energy storage reservoir; The grade evaluation module is connected with the indicator selection module and the model construction module to calculate the evaluation grade; The parameter optimization module is connected with the grade evaluation module to adjust and optimize the operating parameters of the salt cavern energy storage reservoir.

8. A brine discharge and compressed air energy storage system based on an energy storage cavity based on the evaluation method according to any one of claims 1 to 6, characterized in that: include: A compressed air inlet is provided at the top of the energy storage chamber and is used to introduce compressed air into the chamber; A storage chamber for storing compressed air and forming a dynamic interface with brine; The completion casing is arranged in the energy storage chamber, and is provided with an inner brine discharge pipe and an outer brine discharge pipe; The brine discharge inner pipe is connected to the salt rock layer and is used to guide the brine from the salt rock layer into the cavity; The brine discharge outer pipe is connected to the completion casing and is used to discharge brine from the energy storage reservoir cavity; The packer is set in the completion casing to isolate different pressure areas and avoid gas-liquid mixing interference; Protective liquid is filled between the energy storage cavity and the brine to isolate the compressed air from the brine and maintain air tightness and pressure balance; The interlayer is located at the bottom of the energy storage chamber and is used to deposit insoluble sediment; The final gas-brine interface is formed between the compressed air and the protective liquid in the energy storage cavity, which is used to dynamically adjust the interface position of energy storage and brine discharge.

9. A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the processor executes the steps of the method for evaluating the stability level of a salt cavern compressed air energy storage reservoir according to any one of claims 1 and 6.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the salt cavern compressed air energy storage stability grade evaluation system as described in claim 7.

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