Self-adaptive on-line measuring method for basic parameters of coal seam

Abstract

The invention discloses a coal seam basic parameter self-adaptive online measurement method, and relates to the technical field of coal seam parameter acquisition, the method comprises the following steps: S1, deploying a multi-parameter sensor array in a coal seam drill hole, and acquiring original gas pressure, temperature, humidity, coal strain and acoustic emission signals in real time; s2, calculating and correcting gas pressure through a composite environment compensation model; s3, constructing an unsteady state diffusion-seepage equation to invert the gas concentration and the pressure field; s4, performing time-frequency analysis on the acoustic emission signal, and calculating the amount of gas released by micro-fracture; s5, the dynamic gas content is calculated based on the micro-fracture gas release amount; and step S6, constructing an objective function and carrying out parameter dynamic optimization in real time. According to the method, the coal seam parameters are collected and accurately corrected, the problems in coal seam mining work can be solved in an assisted mode, and the production progress of the working face is accelerated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coal seam parameter acquisition, in particular to a coal seam basic parameter self-adaptive online measurement method. BACKGROUND

[0002] Coalbed gas is a potential clean energy. In the current energy shortage situation, accelerating the development and utilization of coalbed gas has important practical significance for improving energy structure, fully utilizing energy and reducing environmental pollution. The most common coalbed development methods mainly include underground gas extraction and surface drilling drainage. The coalbed gas yield of underground extraction is small, the methane concentration is not high, and it is easily affected by coal mining production, so it is mainly for the purpose of coal mine safety production, and the utilization rate of coalbed gas is low. The surface drilling drainage has large gas yield, long gas production time and high methane content, so it can support large-scale commercial utilization. This development method makes people see that coalbed gas can be drained to the ground through a wellbore and utilized like conventional natural gas, so that coalbed gas is truly regarded as a mineral and is listed as a mineral resource with important economic value.

[0003] However, the coalfield geological structure in China is complex, the late reconstruction of part of the coal-bearing basin is strong, the structural forms are various, the coal reservoir and coalbed gas resource occurrence conditions are relatively simple in large and medium-sized basins, and are relatively complex in small basins, the coalbed gas control and utilization are difficult, and many key problems in theory and technical research and application have not been solved, the reasons are that the basic research of coalbed gas development and utilization is weak, the mechanism and influencing factors of the jetting hole phenomenon in the drilling process of the extraction drilling are not clear enough, the existing coalbed gas exploration and development technology cannot adapt to complex geological conditions, and the like. In the process of in-situ coalbed gas extraction, with the continuous migration of gas, the fracture field of the coalbed, and the diffusion field and seepage field of the gas migration will change continuously, and accurate mastering of the evolution law of these physical fields is crucial for realizing efficient extraction of coalbed gas.

[0004] A kind of in-situ coalbed gas extraction multi-physical field synchronous measurement system and method are disclosed in Chinese patent with publication number CN116381185A, relating to coal mine gas extraction technical field, the specific steps are: sampling analysis is carried out to the coal area to be measured to obtain the related parameters of coal seam, and experimental parameters are determined according to the related parameters of coal seam;Based on the experimental parameters, the measurement system of the coal area to be measured is built, and the initial parameter configuration is carried out;The data of the measurement system are collected, and the data of the measurement system are processed to obtain a plurality of physical field parameters;The mapping relationship between a plurality of physical field parameters and different burial depth coal seams under different ground stress conditions is constructed.The present application realizes the synchronous measurement of multiple physical fields in an experimental way, and provides more accurate theoretical basis for coal mining.

[0005] Chinese patent CN112145229B discloses a non-contact dynamic continuous measurement system and method for coal seam gas content in coal roadway tunneling faces. This measurement system comprises three main parts: a multi-parameter dynamic acquisition system, a monitoring system, and a gas content calculation system. The multi-parameter dynamic acquisition system acquires parameters such as coal roadway return air gas concentration, roadway cross-sectional area, roadway perimeter, sensor distance from the tunneling head, and face wind speed at the parameter collection points. This data is then transmitted to the gas content calculation system via the monitoring system. The gas content calculation system acquires, processes, and displays the multi-parameter data signals and controls the drive module of the multi-parameter dynamic acquisition system. The corresponding method can perform a comprehensive "point-line-surface-volume" analysis and inversion of the acquired multi-parameter information. This invention can be widely applied to the observation and research of coal seam gas occurrence patterns in coal roadway tunneling faces.

[0006] All of the above patents suffer from the problems mentioned in this background technology: traditional borehole sealing pressure measurement methods require single-point static measurement and cannot capture dynamic changes; existing sensors do not consider the coupling effect of ground stress-temperature-humidity, resulting in insufficient model accuracy; and traditional gas content models have high prediction errors. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an adaptive online method for determining the basic parameters of coal seams, which addresses the shortcomings of the existing technology.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] An adaptive online method for determining basic parameters of coal seams includes the following steps:

[0010] Step S1: Deploy a multi-parameter sensor array in the coal seam borehole to collect raw gas pressure, temperature, humidity, coal strain and acoustic emission signals in real time;

[0011] Step S2: Calculate the corrected gas pressure using a composite environmental compensation model;

[0012] Step S3: Construct the unsteady diffusion-seepage equation to invert the gas concentration and pressure field;

[0013] Step S4: Perform time-frequency analysis on the acoustic emission signal and calculate the amount of gas released by the micro-rupture;

[0014] Step S5: Calculate the dynamic gas content based on the amount of gas released from micro-fractures;

[0015] Step S6: Construct the objective function and perform dynamic parameter optimization in real time.

[0016] Furthermore, in step S2, the formula for calculating the corrected gas pressure is:

[0017]

[0018] in, This indicates the corrected gas pressure. This indicates the original gas pressure collected. This represents the linear temperature compensation coefficient. This represents the nonlinear temperature compensation coefficient. Indicates real-time temperature. Indicates the reference temperature. Indicates the humidity compensation coefficient. Indicates real-time humidity. Indicates the reference humidity. Represents the stress coupling coefficient. This represents the elastic modulus of the coal. Indicates the strain of the coal body. Indicates the reference stress.

[0019] Furthermore, in the modified gas pressure formula, the compensation coefficient... , and Through orthogonal experimental calibration, under temperature gradients of 15℃, 25℃, and 35℃ and humidity gradients of 30%, 50%, and 70%, the calculation formula is obtained by matrix operations:

[0020]

[0021] in, This represents a 9×3 design matrix, where each row corresponds to one experiment and contains three independent variables: temperature deviation, the square of the temperature deviation, and the humidity deviation. This represents a 9×1 column vector consisting of the compensation bias from 9 experiments, which is the ratio of the actual pressure to the original pressure minus 1.

[0022] Furthermore, in step S3, the specific formula for the unsteady diffusion-seepage equation is as follows:

[0023]

[0024] in, Indicates the free gas molar concentration. Indicates the porosity of the coal seam. Represents a time variable. Indicates the effective diffusion coefficient. Indicates dynamic penetration rate. The second derivative of the gas concentration. Denotes the divergence operator, Indicates the viscosity of methane. The first derivative representing gas pressure, Indicates the density of the coal body. Indicates the amount of gas adsorbed;

[0025] The steps for solving the pressure field are as follows:

[0026] Dynamic permeability, adsorption capacity, and effective diffusion coefficient are calculated using environmental data.

[0027] Solving the unsteady diffusion-seepage equation yields the free gas molar concentration;

[0028] The free gas molar concentration is converted into a pressure field using the ideal gas law.

[0029] Furthermore, in the unsteady diffusion-seepage equation, the formula for calculating the effective diffusion coefficient is:

[0030]

[0031] in, Indicates the baseline diffusivity. Indicates the diffusion activation energy. Represents the gas constant;

[0032] The formula for calculating dynamic permeability is:

[0033]

[0034] in, Indicates permeability under stress-free conditions. Represents the stress sensitivity coefficient. Indicates ground stress;

[0035] The formula for calculating the amount of adsorbed gas is:

[0036]

[0037] in, and These represent the Langmuir volume constant and the Langmuir pressure constant, respectively. Indicates the stress adsorption enhancement coefficient. Indicates the non-uniformity index. This indicates ground stress.

[0038] Furthermore, in step S4, the specific formula for the amount of gas released by micro-fractures is as follows:

[0039]

[0040] in, This indicates the amount of gas released by the micro-fracture. Indicates the acoustic emission conversion coefficient. and Indicates the integration time interval. Represents the acoustic emission energy spectral density. Indicates frequency.

[0041] Furthermore, in step S5, the formula for calculating the dynamic gas content is:

[0042]

[0043] in, This represents the dynamic gas content over time t.

[0044] Furthermore, in step S6, the formula for calculating the objective function is:

[0045]

[0046] in, Describe the objective function. The optimized parameter vector includes: stress sensitivity coefficient, stress adsorption enhancement coefficient, and non-uniformity index. This represents the gas pressure at the location of the gas pressure sensor, representing the pressure field inverted in step S3. This indicates a time window, meaning data within a 10-minute period is being calculated.

[0047] Furthermore, the constraints of the objective function include: stress sensitivity coefficient greater than or equal to 0.01 and less than or equal to 0.2; stress adsorption enhancement coefficient greater than or equal to 0.1 and less than or equal to 0.5; and non-uniformity index greater than or equal to 0.5 and less than or equal to 1.5.

[0048] Furthermore, the convergence condition of the objective function includes:

[0049]

[0050] in, This represents the gradient convergence threshold.

[0051] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0052] 1. This invention achieves dynamic updates of the pressure field every 10 minutes through the inversion of the unsteady diffusion-seepage equation, captures sudden changes in gas pressure in real time, and the pressure field can accurately locate the outburst danger zone.

[0053] 2. This invention uses a multi-physics coupling model to perform dynamic parameter optimization, automatically calibrating the stress sensitivity coefficient, adsorption enhancement coefficient and non-uniformity index every 10 minutes, and the model can adapt to geological changes.

[0054] 3. This invention constructs an intelligent compensation model, which can correct the error of pressure sensor under coal seam environmental conditions by simultaneously correcting temperature, humidity and strain interference through multi-sensor fusion.

[0055] 4. This invention provides a strong basis for coal seam outburst risk identification and regional prediction by continuously and dynamically measuring coal seam gas pressure and content. It can help solve problems such as the connection between mine drainage and mining, accelerate the production progress of the working face, and thus improve the efficiency of coal mining, which has good economic and social benefits. Attached Figure Description

[0056] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0057] Figure 1 This is a flowchart illustrating an embodiment of the present invention;

[0058] Figure 2 This is a schematic diagram of the system structure according to an embodiment of the present invention;

[0059] Figure 3 This is a comparison chart of gas pressure in an embodiment of the present invention. Detailed Implementation

[0060] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0061] like Figure 1 As shown, an adaptive online method for determining basic parameters of coal seams includes the following steps:

[0062] Step S1: Deploy a multi-parameter sensor array in the coal seam borehole to collect raw gas pressure, temperature, humidity, coal strain and acoustic emission signals in real time;

[0063] Step S2: Calculate the corrected gas pressure using a composite environmental compensation model;

[0064] Step S3: Construct the unsteady diffusion-seepage equation to invert the gas concentration and pressure field;

[0065] Step S4: Perform time-frequency analysis on the acoustic emission signal and calculate the amount of gas released by the micro-rupture;

[0066] Step S5: Calculate the dynamic gas content based on the amount of gas released from micro-fractures;

[0067] Step S6: Construct the objective function and perform dynamic parameter optimization in real time.

[0068] In step S2, the formula for calculating the corrected gas pressure is:

[0069]

[0070] in, This indicates the corrected gas pressure. This indicates the original gas pressure collected. This represents the linear temperature compensation coefficient. This represents the nonlinear temperature compensation coefficient. Indicates real-time temperature. Indicates the reference temperature. Indicates the humidity compensation coefficient. Indicates real-time humidity. Indicates the reference humidity. Represents the stress coupling coefficient. This represents the elastic modulus of the coal. Indicates the strain of the coal body. Indicates the reference stress.

[0071] The specific parameter settings are shown in Table 1. The unit is 1 / K. The unit is 1 / K². The unit is 1 / %. The unit is 1 / Pa;

[0072] Table 1

[0073]

[0074] In the modified gas pressure formula, the compensation coefficient , and Through orthogonal experimental calibration, under temperature gradients of 15℃, 25℃, and 35℃ and humidity gradients of 30%, 50%, and 70%, the calculation formula is obtained by matrix operations:

[0075]

[0076] in, This represents a 9×3 design matrix, where each row corresponds to one experiment and contains three independent variables: temperature deviation, the square of the temperature deviation, and the humidity deviation. This represents a 9×1 column vector consisting of the compensation bias from 9 experiments, which is the ratio of the actual pressure to the original pressure minus 1.

[0077] In Table 1, the stress coupling coefficients are... The results were obtained through triaxial loading experiments, specifically including:

[0078] The confining pressure gradient was controlled at 5, 10, 15, and 20 MPa.

[0079] Measure the actual pressure and sensor readings at each stress level;

[0080] Simultaneous measurement of coal body strain;

[0081] Calculate the relative deviation for each stress level;

[0082] Calculate the relative stress change;

[0083] The stress coupling coefficient is obtained by solving linear regression.

[0084] In step S3, the specific formula for the unsteady diffusion-seepage equation is as follows:

[0085]

[0086] in, Indicates the free gas molar concentration. Indicates the porosity of the coal seam. Represents a time variable. Indicates the effective diffusion coefficient. Indicates dynamic penetration rate. The second derivative of the gas concentration. Denotes the divergence operator, Indicates the viscosity of methane. The first derivative representing gas pressure, This indicates the density of the coal body, and the amount of adsorbed methane. Represents the gas constant;

[0087] Among them, free gas molar concentration The unit is mol / m³, and the porosity of the coal seam is... Dimensionless, time variable The unit is s, and the effective diffusion coefficient is... The unit is m² / s, dynamic permeability. The unit is m², and the viscosity of methane is... The unit is Pa·s, the gas constant. The unit is J / (mol·K), temperature The unit is K, the density of coal. The unit is kg / m³, which represents the amount of gas adsorbed. The unit is mol / kg;

[0088] The viscosity of methane is set to a constant: 1.08 × 10⁻⁵ Pa·s;

[0089] The steps for solving the pressure field are as follows:

[0090] Dynamic permeability, adsorption capacity, and effective diffusion coefficient are calculated using environmental data.

[0091] Solving the unsteady diffusion-seepage equation yields the free gas molar concentration;

[0092] The free gas molar concentration is converted into a pressure field using the ideal gas law.

[0093] In the aforementioned unsteady diffusion-seepage equation, the formula for calculating the effective diffusion coefficient is:

[0094]

[0095] in, Indicates the baseline diffusivity. Indicates the diffusion activation energy. Represents the gas constant;

[0096] The formula for calculating dynamic permeability is:

[0097]

[0098] in, Indicates permeability under stress-free conditions. Represents the stress sensitivity coefficient. Indicates ground stress;

[0099] The formula for calculating the amount of adsorbed gas is:

[0100]

[0101] in, and These represent the Langmuir volume constant and the Langmuir pressure constant, respectively. Indicates the stress adsorption enhancement coefficient. Indicates the non-uniformity index. This indicates ground stress.

[0102] Wherein, Langmuir volume constant The unit is mol / kg, Langmuir pressure constant. The unit is 1 / Pa, stress adsorption coefficient Dimensionless, non-uniformity index Dimensionless, the unit of geostress is Pa.

[0103] The specific setting range of the parameters is shown in Table 2.

[0104] Table 2

[0105]

[0106] The Langmuir adsorption isotherm is the fundamental formula describing the adsorption equilibrium of a monolayer. Its standard form is θ=(bP) / (1+bP) or q=ap / (1+ap), where θ is the surface coverage, q is the amount of adsorption, P is the gas pressure, and a and b are the adsorption equilibrium constants related to temperature and heat of adsorption.

[0107] This formula is based on the following core assumptions:

[0108] Adsorption is achieved by a monolayer covering the solid surface; the solid surface is uniform and the adsorption sites have the same energy; there is no interaction between adsorbed molecules; and adsorption and desorption reach a dynamic equilibrium.

[0109] In step S4, the specific formula for the amount of gas released by micro-rupture is as follows:

[0110]

[0111] in, This indicates the amount of gas released by the micro-fracture. Indicates the acoustic emission conversion coefficient. and Indicates the integration time interval. Represents the acoustic emission energy spectral density. Indicates frequency.

[0112] The acoustic emission conversion coefficient was determined through coal sample destructive experiments. It characterizes the number of moles of gas released per unit mass of coal per unit time per unit acoustic emission energy, expressed in mol / (J·s·kg). The amount of gas released from micro-fractures was then calculated. The unit is mol / kg.

[0113] In step S5, the formula for calculating the dynamic gas content is:

[0114]

[0115] in, This represents the dynamic gas content over time t, expressed in mol / kg.

[0116] In step S6, the formula for calculating the objective function is:

[0117]

[0118] in, Describe the objective function. The optimized parameter vector includes: stress sensitivity coefficient, stress adsorption enhancement coefficient, and non-uniformity index. This represents the gas pressure at the location of the gas pressure sensor, representing the pressure field inverted in step S3. This indicates a time window, meaning data within a 10-minute period is being calculated.

[0119] During the optimization process, for each candidate parameter, the diffusion-seepage equation needs to be solved again to obtain a new pressure field, and then the pressure values ​​at the sensor location are extracted to form a sequence. Since solving the diffusion-seepage equation is computationally intensive, in practice, data with a sliding time window (such as 10 minutes) is usually used for optimization, rather than full-time data.

[0120] Improved objective function form: Since solving the diffusion-permeation equation is time-consuming, in the optimization iteration, other parameters (such as diffusion coefficient, initial permeability, etc.) are usually fixed, and only the influence of the optimization parameter vector on permeability and adsorption model is updated, and linear approximation or pre-calculated interpolation table is used to speed up the process.

[0121] The constraints of the objective function include: stress sensitivity coefficient greater than or equal to 0.01 and less than or equal to 0.2; stress adsorption enhancement coefficient greater than or equal to 0.1 and less than or equal to 0.5; and non-uniformity index greater than or equal to 0.5 and less than or equal to 1.5.

[0122] The convergence conditions of the objective function include:

[0123]

[0124] in, This represents the gradient convergence threshold.

[0125] The gradient convergence threshold is set to 1e-4.

[0126] Objective function optimization process: Use iterative algorithms such as gradient descent or Levenberg-Marquardt method to adjust θ and minimize J(θ).

[0127] Repeat this process in each iteration until the convergence condition is met.

[0128] The iterative process of the objective function is illustrated in Table 3.

[0129] Table 3

[0130]

[0131] Coal seam gas (mainly composed of methane) is typically treated as an ideal gas in engineering applications. According to the ideal gas law: PV = nRT, the equation can be transformed into P = (n / V)RT, where n / V is the molar concentration, representing the molar concentration of free gas (free gas) per unit volume of coal seam pores, i.e., the gas concentration C.

[0132] In the unsteady diffusion-seepage equation, the gas concentration C is one of the main variables to be solved. Pressure and concentration are directly related through the ideal gas law; therefore, once C is determined, P can be obtained. This equation assumes that the gas is an ideal gas, which is a reasonable approximation for coal seam gas pressures (typically <10 MPa). Therefore, in the numerical solution process: the concentration field is obtained by solving the partial differential equation, and then the pressure field is calculated using P=CRT.

[0133] like Figure 2 As shown, the present invention is achieved by constructing a three-layer system architecture, including a sensor array, an edge computing unit, and a mine monitoring center.

[0134] The borehole sensor array includes: pressure sensor, temperature and humidity sensor, strain sensor, and acoustic emission sensor;

[0135] The edge computing unit includes: an environmental compensation module, a diffusion-percolation solver, an acoustic emission analysis module, and a parameter optimization engine;

[0136] The mine monitoring center includes: pressure field display and dynamic content display.

[0137] like Figure 3 The image shows a comparison of three pressure curves:

[0138] Dark color: Corrected gas pressure P_c; Dashed line: Pressure at the sensor before optimization; Light color: Pressure at the sensor after optimization.

[0139] The optimized model pressure field is closer to the corrected gas pressure, with the residual changing from 0.18 MPa to 0.02 MPa.

[0140] The examples described herein are merely preferred embodiments of the invention and are not intended to limit the concept and scope of the invention. Any modifications and improvements made by those skilled in the art to the technical solutions of the invention without departing from the design concept of the invention should fall within the protection scope of the invention.

Claims

1. An adaptive online method for determining basic parameters of coal seams, characterized in that, Includes the following steps: Step S1: Deploy a multi-parameter sensor array in the coal seam borehole to collect raw gas pressure, temperature, humidity, coal strain and acoustic emission signals in real time; Step S2: Calculate the corrected gas pressure using a composite environmental compensation model; Step S3: Construct the unsteady diffusion-seepage equation to invert the gas concentration and pressure field; Step S4: Perform time-frequency analysis on the acoustic emission signal and calculate the amount of gas released by the micro-rupture; Step S5: Calculate the dynamic gas content based on the amount of gas released from micro-fractures; Step S6: Construct the objective function and perform dynamic parameter optimization in real time.

2. The method according to claim 1, characterized in that, In step S2, the formula for calculating the corrected gas pressure is: ； in, This indicates the corrected gas pressure. This indicates the original gas pressure collected. This represents the linear temperature compensation coefficient. This represents the nonlinear temperature compensation coefficient. Indicates real-time temperature. Indicates the reference temperature. Indicates the humidity compensation coefficient. Indicates real-time humidity. Indicates the reference humidity. Represents the stress coupling coefficient. This represents the elastic modulus of the coal. Indicates the strain of the coal body. Indicates the reference stress.

3. The method according to claim 2, characterized in that, In the modified gas pressure formula, the compensation coefficient , and Through orthogonal experimental calibration, under temperature gradients of 15℃, 25℃, and 35℃ and humidity gradients of 30%, 50%, and 70%, the calculation formula is obtained by matrix operations: ； in, This represents a 9×3 design matrix, where each row corresponds to one experiment and contains three independent variables: temperature deviation, the square of the temperature deviation, and the humidity deviation. This represents a 9×1 column vector consisting of the compensation bias from 9 experiments, which is the ratio of the actual pressure to the original pressure minus 1.

4. The method according to claim 3, characterized in that, In step S3, the specific formula for the unsteady diffusion-seepage equation is as follows: ； in, Indicates the free gas molar concentration. Indicates the porosity of the coal seam. Represents a time variable. Indicates the effective diffusion coefficient. Indicates dynamic penetration rate. The second derivative of the gas concentration. Denotes the divergence operator, Indicates the viscosity of methane. The first derivative representing gas pressure, Indicates the density of the coal body. Indicates the amount of adsorbed gas. Represents the gas constant; The steps for solving the pressure field are as follows: Dynamic permeability, adsorption capacity, and effective diffusion coefficient are calculated using environmental data. Solving the unsteady diffusion-seepage equation yields the free gas molar concentration; The free gas molar concentration is converted into a pressure field using the ideal gas law.

5. The method according to claim 4, characterized in that, In the aforementioned unsteady diffusion-seepage equation, the formula for calculating the effective diffusion coefficient is: ； in, Indicates the baseline diffusivity. Indicates the diffusion activation energy. Represents the gas constant; The formula for calculating dynamic permeability is: ； in, Indicates permeability under stress-free conditions. Represents the stress sensitivity coefficient. Indicates ground stress; The formula for calculating the amount of adsorbed gas is: ； in, and These represent the Langmuir volume constant and the Langmuir pressure constant, respectively. Indicates the stress adsorption enhancement coefficient. Indicates the non-uniformity index. This indicates ground stress.

6. The method according to claim 5, characterized in that, In step S4, the specific formula for the amount of gas released by micro-rupture is as follows: ； in, This indicates the amount of gas released by the micro-fracture. Indicates the acoustic emission conversion coefficient. and Indicates the integration time interval. Represents the acoustic emission energy spectral density. Indicates frequency.

7. The method according to claim 6, characterized in that, In step S5, the formula for calculating the dynamic gas content is: ； in, This represents the dynamic gas content over time t.

8. The method according to claim 7, characterized in that, In step S6, the formula for calculating the objective function is: ； in, Describe the objective function. The optimized parameter vector includes: stress sensitivity coefficient, stress adsorption enhancement coefficient, and non-uniformity index. This represents the gas pressure at the location of the gas pressure sensor, representing the pressure field inverted in step S3. This indicates a time window, meaning data within a 10-minute period is being calculated.

9. The method according to claim 8, characterized in that, The constraints of the objective function include: stress sensitivity coefficient greater than or equal to 0.01 and less than or equal to 0.2; stress adsorption enhancement coefficient greater than or equal to 0.1 and less than or equal to 0.5; and non-uniformity index greater than or equal to 0.5 and less than or equal to 1.

5.

10. The method according to claim 9, characterized in that, The convergence conditions of the objective function include: ； in, This represents the gradient convergence threshold.

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