Method, device and equipment for evaluating effective volume of salt cavern cavity, medium and product

Abstract

The invention discloses a salt cavern cavity effective volume evaluation method and device, equipment, a medium and a product, and relates to the technical field of energy storage, the method comprises the following steps: collecting test data of a target salt cavern cavity water seal pressure test at each time point, and dividing the water seal pressure test into a pressure increasing stage and a pressure maintaining stage at a boundary time point; acquiring a time sequence, an accumulated injection volume sequence and a cavity pressure sequence corresponding to the injection of the brine at a constant rate based on the test data; based on the time sequence, the accumulated injection volume sequence and the cavity pressure sequence, the total injection volume of brine injection is decomposed into an instantaneous elastic volume, a creep volume and a sediment compression volume, and a first equation is established; establishing a total fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume and a first equation; and obtaining the effective volume of the cavity based on the total fitting function. The contribution of different volume components to the total injection volume can be effectively distinguished, so that the accuracy of effective volume evaluation of the salt cavern cavity is improved.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a method, apparatus, equipment, medium and product for evaluating the effective volume of a salt cavern. Background Technology

[0002] As a critical infrastructure for strategic energy storage, the accurate determination of the effective volume of underground salt caverns has a comprehensive impact on the engineering design, long-term safe operation, and economic efficiency optimization of energy storage facilities. In energy storage practice, the effective volume of the salt cavern cavity is directly related to the upper limit of storage capacity and the control of operating costs, and is a core technical indicator for promoting the large-scale application of underground salt caverns.

[0003] Water-tight pressure testing, as a fundamental evaluation method, indirectly derives the volumetric characteristics of a cavity by injecting brine into the cavity at a constant rate and simultaneously collecting pressure, time, and cumulative volume data. However, existing technologies have significant shortcomings in processing pressure test data: they fail to effectively decouple the instantaneous elastic response during the pressurization phase, the rock creep effect during the pressure holding phase, and the compression behavior of the sediment layer.

[0004] Traditional methods simply attribute the total injection volume to changes in the volume of a single cavity, neglecting the independent physical mechanisms of instantaneous elastic volume, creep volume, and sediment compression volume. This data processing approach leads to a systematic deviation of the assessment results from the true value, severely underestimating the actual storage capacity of salt cavern cavities. Consequently, it results in inaccurate energy storage capacity planning, low resource utilization efficiency, and potential safety risks, hindering the in-depth development and widespread application of underground salt caverns in the field of energy storage. Summary of the Invention

[0005] The purpose of this application is to provide a method, apparatus, equipment, medium, and product for evaluating the effective volume of salt caverns, which improves the accuracy of evaluating the effective volume of salt caverns, thereby optimizing energy storage capacity planning, improving resource utilization efficiency, and reducing safety risks.

[0006] To achieve the above objectives, this application provides the following solution: In a first aspect, this application provides a method for evaluating the effective volume of a salt cavern cavity, comprising: collecting test data at each time point during a water-sealed pressure test of a target salt cavern cavity, wherein a dividing time point divides the water-sealed pressure test into a pressure-increasing stage and a pressure-holding stage, the dividing time point being the time point at which the cavity pressure value increases from the initial pressure value to the test pressure value, and the cavity pressure during the pressure-holding stage remaining unchanged at the test pressure value; obtaining, based on the test data, a time series, a cumulative injection volume series, and a cavity pressure series corresponding to the injection of brine at a constant rate; decomposing the total injection volume of brine into an instantaneous elastic volume, a creep volume, and a sediment compression volume based on the time series, the cumulative injection volume series, and the cavity pressure series, and establishing a first formula, wherein the instantaneous elastic volume corresponds to the pressure-increasing stage, and the creep volume and the sediment compression volume correspond to the pressure-holding stage; establishing a total fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula; and obtaining the effective volume of the cavity based on the total fitting function.

[0007] Optionally, based on the time series, the cumulative injection volume series, and the cavity pressure series, the total injection volume of brine is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume, and a first formula is established, specifically including: The total injection volume is extracted from the cumulative injection volume sequence, where the total injection volume is the cumulative injection volume corresponding to the last time point in the time series; The pressure change value is extracted from the cavity pressure sequence, and the pressure change value is substituted into the second formula to calculate the instantaneous elastic volume; The holding time is extracted from the time series, and the holding time and the pressure change value are substituted into the third formula to obtain the creep volume; Substituting the pressure holding time and the pressure change value into the fourth formula, the sludge compression volume is obtained; Let the total injection volume equal the sum of the instantaneous elastic volume, the creep volume, and the sediment compression volume to obtain the first formula.

[0008] Optionally, the step of extracting pressure change values ​​from the cavity pressure sequence and substituting the pressure change values ​​into the second formula to calculate the instantaneous elastic volume includes: The pressure change value is obtained by calculating the difference between the test pressure value and the initial pressure value. If we assume the pressure change value is... If P is the instantaneous elastic volume and V1 is the value, then the second formula is: Wherein, K is the instantaneous elastic volume coefficient; The step of extracting the holding time from the time series and substituting the holding time and the pressure change value into the third formula to obtain the creep volume includes: The total injection volume is defined as the time point in the time series as the end time point; The difference between the end time point and the boundary time point is calculated to obtain the pressure holding time; If the holding time is t, the creep volume is... Then the third formula is: Wherein, A is the creep coefficient, and n and m are power exponent parameters related to the creep characteristics of rocks; The step of substituting the holding time and the pressure change value into the fourth formula to obtain the sludge compression volume includes: If the compressed volume of the sediment is ? Then the fourth formula is: Where B is the maximum compressible volume coefficient of the sediment, and C is the consolidation coefficient. It is a natural exponential function; If the total injection volume is... Then the first formula is: .

[0009] Optionally, establishing the overall fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula includes: Let the total injection volume equal to the sum of the second, third, and fourth formulas, to obtain the total fitting function: Among them, the , and K, A, B, C, n, and m are known quantities, while K, A, B, C, n, and m are unknown quantities.

[0010] Optionally, obtaining the effective volume of the cavity based on the total fitting function includes: The initial estimates of each of the unknown quantities are used as constraints on the overall fitting function; The least squares method is used to perform a global fitting of the total fitting function to obtain the simulated values ​​and simulation results of each unknown quantity; Substitute the simulated value of the instantaneous elastic volume coefficient into the fifth formula to obtain the effective volume of the target salt cavern cavity; If the effective volume of the cavity is V, then the fifth formula is: in, It represents the combined elastic compressibility coefficient of the brine and the intact surrounding rock.

[0011] Optionally, obtaining the effective volume of the cavity based on the total fitting function further includes: The effective volume of the cavity, the simulated values ​​of each of the unknown quantities, and the simulation results are analyzed to obtain an evaluation opinion.

[0012] In a second aspect, this application provides a device for evaluating the effective volume of a salt cavern cavity, based on the method for evaluating the effective volume of a salt cavern cavity as described in any of the first aspects above, wherein the device for evaluating the effective volume of a salt cavern cavity includes: The data acquisition module is used to collect test data at each time point of the water seal pressure test of the target salt cavern cavity. The dividing time point divides the water seal pressure test into a pressure increase stage and a pressure holding stage. The dividing time point is the time point when the cavity pressure value increases from the initial pressure value to the test pressure value. During the pressure holding stage, the cavity pressure remains unchanged at the test pressure value. The acquisition module is used to acquire the time series, cumulative injection volume series and cavity pressure series corresponding to the constant rate injection of brine based on the test data; The calculation module is used to decompose the total injection volume of brine into instantaneous elastic volume, creep volume and sediment compression volume based on the time series, the cumulative injection volume series and the cavity pressure series, and establish a first formula, wherein the instantaneous elastic volume corresponds to the pressurization stage, and the creep volume and sediment compression volume correspond to the pressure holding stage. The fitting module is used to establish a total fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula; The output module is used to obtain the effective volume of the cavity based on the total fitting function.

[0013] Thirdly, this application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the salt cavern effective volume assessment method described in any one of the above.

[0014] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the salt cavern effective volume evaluation method described above.

[0015] Fifthly, this application provides a computer program product, including a computer program that, when executed by a processor, implements the steps of the salt cavern effective volume evaluation method described above.

[0016] According to the specific embodiments provided in this application, the following technical effects are disclosed: This application provides a method, apparatus, equipment, medium, and product for evaluating the effective volume of a salt cavern cavity. The method provided in this application collects test data at each time point during the water seal pressure test of the target salt cavern cavity. The water seal pressure test is divided into a pressure-increasing stage and a pressure-holding stage based on boundary time points. Based on the time series, cumulative injected volume series, and cavity pressure series, the total injected volume is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume. A total fitting function is then established to obtain the effective volume of the cavity. Therefore, this method can effectively distinguish the contribution of different volume components to the total injected volume, avoiding the underestimation of the evaluation results caused by the inability to distinguish these volumes in traditional methods. This improves the accuracy of the effective volume evaluation of salt cavern cavities and provides more reliable data support for the planning, design, and safe operation of underground salt cavern energy storage facilities. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 A flowchart illustrating a method for evaluating the effective volume of a salt cavern cavity provided in this application; Figure 2 A schematic flowchart illustrating the effective volume assessment method for salt caverns provided in this application embodiment; Figure 3 for Figure 2 In step S209, a flowchart illustrating the process of obtaining the effective volume of the cavity based on the total fitting function is shown. Figure 4 A schematic diagram of the functional modules of the salt cavern effective volume assessment device provided in the embodiments of this application; Figure 5 A schematic diagram of the structure of a computer device provided in an embodiment of this application. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] Please see Figures 1-5 , Figure 1 This is a flowchart illustrating a method for evaluating the effective volume of a salt cavern cavity, as provided in this application. Figure 2 This is a schematic diagram illustrating the specific process of the method for evaluating the effective volume of a salt cavern cavity provided in the embodiments of this application. Figure 3 for Figure 2 In step S209, a flowchart illustrating the process of obtaining the effective volume of the cavity based on the overall fitting function is shown. Figure 4 This is a schematic diagram of the functional modules of the salt cavern effective volume assessment device provided in the embodiments of this application. Figure 5 A schematic diagram of the structure of a computer device provided in an embodiment of this application.

[0022] This application provides a method for evaluating the effective volume of a salt cavern, referring to... Figure 1 As shown, this method for evaluating the effective volume of salt caverns addresses the technical problem of traditional evaluation methods that treat the surrounding rock as a rigid elastic body, neglect sediment and long-term deformation of the surrounding rock, leading to an underestimation of the true effective volume. The method includes the following steps: S101. Collect test data at each time point during the water seal pressure test of the target salt cavern cavity.

[0023] In some embodiments, the above step S101 (collecting test data at each time point of the water seal pressure test of the target salt cavern cavity) may include: collecting test data at each time point of the water seal pressure test of the target salt cavern cavity, wherein the dividing time point divides the water seal pressure test into a pressure-increasing stage and a pressure-holding stage, the dividing time point is the time point at which the cavity pressure value increases from the initial pressure value to the test pressure value, and the cavity pressure in the pressure-holding stage remains unchanged at the test pressure value.

[0024] The water seal pressure test of the salt cavern cavity refers to the process of injecting brine into the salt cavern cavity (gas storage tank) and monitoring the pressure changes inside the cavity to evaluate the cavity's sealing performance and structural stability. This test process is led by computer equipment and implemented in conjunction with supporting hardware, including a high-precision pressure sensor and flow meter connected to the computer, as well as injection control equipment and the salt cavern cavity. The high-precision pressure sensor is installed at the wellhead to detect the internal pressure of the cavity, and the flow meter is installed in the injection pipeline to detect the volume of the injected liquid (brine). Brine is chosen because it is consistent with the residual liquid in the actual operation of the gas storage tank, and the test results are closer to the real situation.

[0025] Specifically, the computer issues commands to control the injection control equipment to perform a water seal pressure test. First, the wellhead valve of the salt cavern is closed to ensure the cavity is sealed. Then, brine is continuously injected into the cavity at a constant rate through the injection pipeline. When the internal pressure of the cavity reaches the preset test pressure value from the initial pressure value (which can be atmospheric pressure and is negligible), the internal pressure of the cavity is maintained at the test pressure value for 24-48 hours. The purpose is to fully demonstrate the long-term deformation of the surrounding rock and the compaction effect of the sediment, avoiding the omission of key data. At the same time, the computer collects test data at high frequency at every time point throughout the process. The test data can include time, cumulative injection volume, and wellhead pressure (cavity pressure).

[0026] Wherein, time refers to all time points from the start of brine injection to the end of pressure holding; cumulative injection volume is the total cumulative value of brine injected at each time point from the start of brine injection to the end of pressure holding; wellhead pressure (cavity pressure) is the pressure value inside the cavity at each time point.

[0027] S102. Obtain time series, cumulative injection volume sequence and cavity pressure sequence based on collected test data.

[0028] In some embodiments, the above step S102 (obtaining time series, cumulative injection volume sequence and cavity pressure sequence based on collected test data) may include: obtaining the time series, cumulative injection volume sequence and cavity pressure sequence corresponding to brine injected at a constant rate based on test data.

[0029] For example, if the time point at which the brine injection begins is t1, and the time point at which the pressure holding ends is t... x Then the time series can be (t1, t2, ... t). x ), where t1 can be the first second, t2 can be the second second, and so on. x It can be the xth second.

[0030] Similarly, the cumulative injection volume sequence can be (v1, v2, ... v) x The cavity pressure sequence can be (p1, p2, ... p).x It should be noted that each time point corresponds to a unique cavity pressure value and cumulative injection volume value, for example, t 10 Corresponding to p 10 and v 10 .

[0031] S103. The total injection volume is decomposed based on the time series, cumulative injection volume series and cavity pressure series, and the first formula is established.

[0032] In some embodiments, the implementation of step S103 (decomposing the total injection volume based on the time series, cumulative injection volume series, and cavity pressure series, and establishing the first formula) may include: Based on time series, cumulative injection volume series, and cavity pressure series, the total injection volume of brine is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume, and a first formula is established. The instantaneous elastic volume corresponds to the pressurization stage, while the creep volume and sediment compression volume correspond to the pressure holding stage.

[0033] Specifically, during the pressurization phase, the change in cavity volume is primarily attributed to instantaneous elastic deformation; during the pressure holding phase, the volume change is attributed to creep and sediment compression, respectively, by observing the trend of cavity volume change over time. The instantaneous elastic volume corresponds to the pressurization phase, while the creep volume and sediment compression volume correspond to the pressure holding phase. The first formula is a mathematical expression describing the relationship between the total injected volume and the instantaneous elastic volume, creep volume, and sediment compression volume. This formula decomposes the total injected volume into different components; it effectively distinguishes the contribution of different volume components to the total injected volume, avoiding the underestimation of evaluation results caused by the inability to distinguish these volumes in traditional methods, thereby improving the accuracy of the effective volume assessment of the salt cavern cavity.

[0034] S104. Based on the instantaneous elastic volume, creep volume, sediment compression volume, and the first formula, establish the overall fitting function.

[0035] The overall fitting function refers to the function established based on the first equation and combined with specific mathematical models of instantaneous elastic volume, creep volume, and sediment compression volume, used to fit the actual test data. This function contains unknown parameters that need to be determined.

[0036] S105. Based on the total fitting function, the effective volume of the cavity is obtained.

[0037] The effective volume of a salt cavern refers to the volume of fluid that a salt cavern can effectively store under actual operating conditions. This volume is a key parameter for evaluating the capacity and stability of salt cavern energy storage facilities.

[0038] The effective volume assessment method for salt cavern cavities provided in this application collects test data at each time point during the water seal pressure test of the target salt cavern cavity. The water seal pressure test is divided into a pressure-increasing stage and a pressure-holding stage based on the boundary time points. Based on the time series, cumulative injected volume series, and cavity pressure series, the total injected volume is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume. A total fitting function is then established to obtain the effective volume of the cavity. Therefore, this method can effectively distinguish the contribution of different volume components to the total injected volume, avoiding the underestimation of the assessment results caused by the inability to distinguish these volumes in traditional methods. This improves the accuracy of the effective volume assessment of salt cavern cavities and provides more reliable data support for the planning, design, and safe operation of underground salt cavern energy storage facilities.

[0039] As an extension and refinement of the above embodiments, this application provides a first embodiment of a method for evaluating the effective volume of a salt cavern, referring to... Figure 2 As shown, the effective volume assessment method for salt caverns in this embodiment includes the following steps: S201. Collect test data at each time point during the water seal pressure test of the target salt cavern cavity.

[0040] The specific content of step S201 is the same as that of step S101, and this step will not be described in detail here.

[0041] S202. Obtain time series, cumulative injection volume sequence and cavity pressure sequence based on collected test data.

[0042] The specific content of step S202 is the same as that of step S102, and this step will not be described in detail here.

[0043] S203. Extract the total injection volume from the cumulative injection volume sequence. The total injection volume is the cumulative injection volume corresponding to the last time point in the time series.

[0044] S204. Extract the pressure change value from the cavity pressure sequence and substitute the pressure change value into the second formula to calculate the instantaneous elastic volume.

[0045] In an exemplary embodiment, step S204 (extracting pressure change values ​​from the cavity pressure sequence and substituting the pressure change values ​​into the second formula to calculate the instantaneous elastic volume) may specifically include: Calculate the difference between the test pressure value and the initial pressure value to obtain the pressure change value.

[0046] The initial pressure can be atmospheric pressure, and the initial pressure value can be approximated as 0. Then the pressure change value is equal to the test pressure value.

[0047] For example, if the pressure change value is set to... Given P, and the instantaneous elastic volume V1, the two equations are: Wherein, K is the instantaneous elastic volume coefficient, a parameter used to describe "how much the elastic volume changes when the pressure changes by 1 unit".

[0048] Step S204 above P can accurately reflect the pressure increment of the cavity from the initial state to the test state and is the direct driving force of the instantaneous elastic response. The second formula is based on the principle of elasticity and directly correlates the instantaneous elastic deformation of the cavity under pressure with the pressure change value.

[0049] S205. Extract the holding time from the time series, and substitute the holding time and pressure change value into the third formula to obtain the creep volume.

[0050] In an exemplary embodiment, step S205 (extracting the holding time from the time series and substituting the holding time and pressure change value into the third formula to obtain the creep volume) may specifically include: The total injection volume is defined as the time point in the time series as the end time point; Calculate the difference between the end time point and the boundary time point to obtain the pressure holding time; For example, if the holding time is t and the creep volume is... Then the third equation is: Where A is the creep coefficient, and n and m are power exponent parameters related to the creep characteristics of rocks (n is usually >1, m <1).

[0051] This calculation method can accurately define the actual duration of the cavity being in a pressure-holding state during the brine injection process. The third formula takes into account the plastic deformation of the salt rock under constant pressure over time. By introducing the creep coefficient A and the power exponent parameters n and m related to the creep characteristics of the rock, the creep behavior of the salt rock can be simulated more accurately.

[0052] S206. Substitute the holding time and pressure change value into the fourth formula to obtain the sludge compression volume.

[0053] In an exemplary embodiment, step S206 (substituting the holding time and pressure change value into the fourth formula to obtain the sludge compression volume) may specifically include: For example, let the compressed volume of the sediment be... Then the fourth equation is: Where B is the maximum compressible volume coefficient of the sediment, and C is the consolidation coefficient. It is a natural exponential function.

[0054] Step S206 above aims to quantify the compression and consolidation phenomenon of the sediment at the bottom of the cavity under pressure over time, by introducing time t. P can dynamically describe the compression process of sediment.

[0055] S207. Let the total injection volume equal the sum of the instantaneous elastic volume, the creep volume, and the sediment compression volume to obtain the first formula.

[0056] For example, let the total injection volume be... Then the first equation is: .

[0057] The first formula decomposes the total injection volume into different components; it effectively distinguishes the contribution of different volume components to the total injection volume, avoiding the underestimation of the evaluation results caused by the inability to distinguish these volumes in traditional methods, thereby improving the accuracy of the effective volume assessment of the salt cavern cavity.

[0058] S208. Based on the instantaneous elastic volume, creep volume, sediment compression volume, and the first formula, establish the overall fitting function.

[0059] In an exemplary embodiment, step S208 (establishing a total fitting function based on instantaneous elastic volume, creep volume, sediment compression volume, and the first formula) may specifically include: For example, by setting the total injection volume equal to the sum of the second, third, and fourth equations, we obtain the overall fitting function: in, , and K is a known quantity, and K, A, B, C, n and m are unknown quantities.

[0060] Specifically, the overall fitting function integrates the various deformation mechanisms (elastic deformation, creep deformation, and sediment consolidation compression) exhibited by the salt cavern during the water-sealed pressure test, providing a basis for subsequent inversion of the cavity characteristic parameters through measured data.

[0061] V P (pressure change) and t V P is the difference between the test pressure and the initial pressure, and t is the duration of the pressure holding phase. These known quantities constitute the input data for the fitting process. K (instantaneous elastic volume coefficient), A (creep coefficient), B (maximum compressible volume coefficient of sediment), C (consolidation coefficient), n, and m (power exponent parameters related to rock creep characteristics) are unknown quantities, representing the physical and mechanical properties of the salt cavern cavity and its surrounding rock. These unknown quantities cannot be directly measured and need to be solved by fitting data to the overall fitting function. Clearly distinguishing between known and unknown quantities is a key prerequisite for parameter inversion and model fitting. It guides subsequent optimization algorithms (such as the least squares method) on how to use known data to iteratively solve for the best estimates of unknown parameters.

[0062] S209. Based on the total fitting function, the effective volume of the cavity is obtained.

[0063] In an exemplary embodiment, such as Figure 3 As shown, step S209 (obtaining the effective volume of the cavity based on the total fitting function) can specifically include: 301. Use the initial estimates of each unknown quantity as constraints on the overall fitted function.

[0064] Specifically, these initial estimates provide a reasonable starting point for subsequent optimization algorithms, guiding them to search within an effective parameter space, thereby improving convergence speed and the likelihood of finding the global optimum. For example, the initial estimate of the instantaneous elastic volume coefficient K can be preliminarily set based on theoretical or empirical data such as the elastic modulus of the salt rock, the initial geometric dimensions of the cavity, and the compressibility of the brine; the creep coefficient A, the maximum compressible volume coefficient B of the sediment, the consolidation coefficient C, and the power exponent parameters n and m can be estimated by referring to the operational experience of salt caverns under similar geological conditions, rock mechanics experimental data, or typical values ​​in relevant literature. These initial estimates, as constraints, ensure that the fitting process is physically reasonable and avoid the algorithm getting trapped in local optima that do not conform to reality.

[0065] 302. Use the least squares method to perform global fitting on the total fitting function to obtain the simulated values ​​and simulation results of each unknown quantity.

[0066] Specifically, through global fitting using the least squares method, the algorithm iteratively adjusts these unknowns until the deviation between the cumulative injection volume predicted by the overall fitting function and the actual observed cumulative injection volume is minimized. Global fitting ensures that all unknown parameters are optimally estimated across the entire watertight pressure test data range, thereby improving the overall fitting accuracy and parameter reliability of the model. After fitting, simulated values ​​for each unknown (K, A, B, C, n, m) are obtained, along with the simulation results obtained by substituting these simulated values ​​into the overall fitting function, i.e., the predicted cumulative injection volume sequence.

[0067] 303. Substitute the simulated value of the instantaneous elastic volume coefficient into the fifth formula to obtain the effective volume of the target salt cavern cavity.

[0068] For example, if the effective volume of the cavity is V, then the fifth formula is: in, It represents the combined elastic compressibility coefficient of the brine and the intact surrounding rock.

[0069] Specifically, in the aforementioned least-squares global fitting process, the simulated value of the instantaneous elastic volume coefficient K is precisely determined. This K value directly reflects the elastic deformation characteristics of the salt cavern cavity under instantaneous pressure. By multiplying this K value by the pre-determined comprehensive elastic compressibility coefficient Ce of the brine and the intact surrounding rock, the effective volume V of the cavity can be directly calculated. Ce is a comprehensive parameter that considers the bulk elastic modulus of the brine and the elastic modulus, Poisson's ratio, and other mechanical properties of the surrounding rock (such as salt rock), reflecting the overall elastic response capability of the entire salt cavern system under pressure changes. In this way, the complex fitting results are ultimately transformed into an intuitive and practically engineering-significant effective volume of the cavity.

[0070] Optionally, obtaining the effective volume of the cavity based on the overall fitting function may further include: The effective volume of the cavity, the simulated values ​​of various unknowns, and the simulation results are analyzed to obtain evaluation opinions.

[0071] The simulation results may include: a comparison graph of the fitted curve and the measured data, and the goodness of fit.

[0072] Specifically, the effective volume of the cavity (the actual effective volume of the salt cavern gas storage) can be directly used for engineering capacity planning (such as how many cubic meters of natural gas can be stored); the physical properties of the surrounding rock and sediment can be described by the simulated values ​​of various unknown quantities; the accuracy of the model can be intuitively displayed by comparing the fitted curve with the measured data, and labeled with "goodness of fit" (a value between 0 and 1, the closer to 1, the more accurate the model).

[0073] Geological and engineering interpretations can be performed based on the effective volume of the cavity, the simulated values ​​of various unknowns, and the simulation results. For example, if parameter B (maximum compressible volume coefficient of sediment) is large, it indicates that there is a large amount of sediment at the bottom of the salt cavern and that it is highly loose. During operation, there may be a risk of "sand discharge" (sediment being carried out by gas), which will wear down pipelines and equipment, and sediment needs to be cleaned in advance. If parameter A (creep volume coefficient) is large, it indicates that the long-term deformation (creep) of the surrounding rock is significant. After long-term operation, the effective volume of the salt cavern will gradually decrease, and the operating pressure needs to be adjusted (such as reducing the maximum pressure) to slow down the deformation of the surrounding rock and ensure the long-term stability of the gas storage facility.

[0074] Based on the same inventive concept, this application also provides a device for evaluating the effective volume of a salt cavern cavity as described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the effective volume evaluation device for salt cavern cavity provided below can be found in the limitations of the effective volume evaluation method for salt cavern cavity described above, and will not be repeated here.

[0075] In one exemplary embodiment, such as Figure 4 As shown, a device for evaluating the effective volume of a salt cavern is provided, comprising: The acquisition module 401 is used to acquire test data at each time point of the water seal pressure test of the target salt cavern cavity. The dividing time point divides the water seal pressure test into a pressure increase stage and a pressure holding stage. The dividing time point is the time point when the cavity pressure value increases from the initial pressure value to the test pressure value. During the pressure holding stage, the cavity pressure remains unchanged at the test pressure value. The acquisition module 402 is used to acquire the time series, cumulative injection volume series and cavity pressure series corresponding to the constant rate injection of brine based on the test data; The calculation module 403 is used to decompose the total injection volume of brine into instantaneous elastic volume, creep volume and sediment compression volume based on time series, cumulative injection volume series and cavity pressure series, and establish a first formula, wherein the instantaneous elastic volume corresponds to the pressurization stage, and the creep volume and sediment compression volume correspond to the pressure holding stage. The fitting module 404 is used to establish a total fitting function based on the instantaneous elastic volume, creep volume, sediment compression volume and the first formula; Output module 405 is used to obtain the effective volume of the cavity based on the total fitting function.

[0076] In one exemplary embodiment, a computer device is provided, which may be a server or a terminal, and its internal structure diagram may be as follows. Figure 5As shown, this computer device includes a processor, memory, input / output (I / O) interfaces, and a communication interface. The processor, memory, and I / O interfaces are connected via a system bus, and the communication interface is also connected to the system bus via the I / O interfaces. The processor provides computational and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system, computer programs, and a database. The internal memory provides the environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The database stores video tag processing data. The I / O interfaces are used for exchanging information between the processor and external devices. The communication interface is used for communication with external terminals via a network connection. When executed by the processor, the computer program implements a method for evaluating the effective volume of a salt cavern.

[0077] Those skilled in the art will understand that Figure 5 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0078] In one exemplary embodiment, a computer device is also provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the steps in the above-described method embodiments.

[0079] In one exemplary embodiment, a computer-readable storage medium is provided storing a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0080] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0081] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of the relevant data must comply with relevant regulations.

[0082] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM).

[0083] The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, etc., and are not limited to these.

[0084] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0085] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for evaluating the effective volume of a salt cavern cavity, characterized in that, The method for evaluating the effective volume of the salt cavern includes: Test data are collected at each time point during the water seal pressure test of the target salt cavern cavity. The water seal pressure test is divided into a pressure increase stage and a pressure holding stage by the dividing time point. The dividing time point is the time point when the cavity pressure value increases from the initial pressure value to the test pressure value. During the pressure holding stage, the cavity pressure remains unchanged at the test pressure value. Based on the test data, the time series, cumulative injection volume series, and cavity pressure series corresponding to the constant rate injection of brine were obtained. Based on the time series, the cumulative injection volume series, and the cavity pressure series, the total injection volume of brine is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume, and a first formula is established, wherein the instantaneous elastic volume corresponds to the pressurization stage, and the creep volume and the sediment compression volume correspond to the pressure holding stage. Based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula, a total fitting function is established; The effective volume of the cavity is obtained based on the overall fitting function.

2. The method for evaluating the effective volume of a salt cavern cavity according to claim 1, characterized in that, Based on the time series, the cumulative injection volume series, and the cavity pressure series, the total injection volume of brine is decomposed into instantaneous elastic volume, creep volume, and sediment compression volume, and a first formula is established, specifically including: The total injection volume is extracted from the cumulative injection volume sequence, where the total injection volume is the cumulative injection volume corresponding to the last time point in the time series; The pressure change value is extracted from the cavity pressure sequence, and the pressure change value is substituted into the second formula to calculate the instantaneous elastic volume; The holding time is extracted from the time series, and the holding time and the pressure change value are substituted into the third formula to obtain the creep volume; Substituting the pressure holding time and the pressure change value into the fourth formula, the sludge compression volume is obtained; Let the total injection volume equal the sum of the instantaneous elastic volume, the creep volume, and the sediment compression volume to obtain the first formula.

3. The method for evaluating the effective volume of a salt cavern cavity according to claim 2, characterized in that, The step of extracting pressure change values ​​from the cavity pressure sequence and substituting these pressure change values ​​into the second formula to calculate the instantaneous elastic volume includes: The pressure change value is obtained by calculating the difference between the test pressure value and the initial pressure value. If we assume the pressure change value is... If P is the instantaneous elastic volume and V1 is the value, then the second formula is: Wherein, K is the instantaneous elastic volume coefficient; The step of extracting the holding time from the time series and substituting the holding time and the pressure change value into the third formula to obtain the creep volume includes: The total injection volume is defined as the time point in the time series as the end time point; The difference between the end time point and the boundary time point is calculated to obtain the pressure holding time; If the holding time is t, the creep volume is... Then the third formula is: Wherein, A is the creep coefficient, and n and m are power exponent parameters related to the creep characteristics of rocks; The step of substituting the holding time and the pressure change value into the fourth formula to obtain the sludge compression volume includes: If the compressed volume of the sediment is ? Then the fourth formula is: Where B is the maximum compressible volume coefficient of the sediment, and C is the consolidation coefficient. It is a natural exponential function; If the total injection volume is ... Then the first formula is: 。 4. The method for evaluating the effective volume of a salt cavern cavity according to claim 3, characterized in that, The establishment of a total fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula includes: Let the total injection volume equal to the sum of the second, third, and fourth formulas, to obtain the total fitting function: Among them, the , and K, A, B, C, n, and m are known quantities, while K, A, B, C, n, and m are unknown quantities.

5. The method for evaluating the effective volume of a salt cavern cavity according to claim 4, characterized in that, The process of obtaining the effective volume of the cavity based on the total fitting function includes: The initial estimates of each of the unknown quantities are used as constraints on the overall fitting function; The least squares method is used to perform a global fitting of the total fitting function to obtain the simulated values ​​and simulation results of each unknown quantity; Substitute the simulated value of the instantaneous elastic volume coefficient into the fifth formula to obtain the effective volume of the target salt cavern cavity; If the effective volume of the cavity is V, then the fifth formula is: in, It represents the combined elastic compressibility coefficient of the brine and the intact surrounding rock.

6. The method for evaluating the effective volume of a salt cavern cavity according to claim 5, characterized in that, The process of obtaining the effective volume of the cavity based on the total fitting function further includes: The effective volume of the cavity, the simulated values ​​of each of the unknown quantities, and the simulation results are analyzed to obtain an evaluation opinion.

7. A device for evaluating the effective volume of a salt cavern, characterized in that, Based on the method for evaluating the effective volume of a salt cavern cavity as described in any one of claims 1-6, the effective volume evaluation device for the salt cavern cavity includes: The data acquisition module is used to collect test data at each time point of the water seal pressure test of the target salt cavern cavity. The dividing time point divides the water seal pressure test into a pressure increase stage and a pressure holding stage. The dividing time point is the time point when the cavity pressure value increases from the initial pressure value to the test pressure value. The cavity pressure in the pressure holding stage remains unchanged at the test pressure value. The acquisition module is used to acquire the time series, cumulative injection volume series and cavity pressure series corresponding to the constant rate injection of brine based on the test data; The calculation module is used to decompose the total injection volume of brine into instantaneous elastic volume, creep volume and sediment compression volume based on the time series, the cumulative injection volume series and the cavity pressure series, and establish a first formula, wherein the instantaneous elastic volume corresponds to the pressurization stage, and the creep volume and sediment compression volume correspond to the pressure holding stage. The fitting module is used to establish a total fitting function based on the instantaneous elastic volume, the creep volume, the sediment compression volume, and the first formula; The output module is used to obtain the effective volume of the cavity based on the total fitting function.

8. A computer device, comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that the processor executes the computer program to implement the steps of the method for evaluating the effective volume of a salt cavern cavity according to any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of the method for evaluating the effective volume of a salt cavern cavity as described in any one of claims 1-6.

10. A computer program product, comprising a computer program, characterized in that, When executed by a processor, the computer program implements the steps of the method for evaluating the effective volume of a salt cavern cavity as described in any one of claims 1-6.

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