Abnormal high-pressure gas reservoir reserve and productivity evaluation method based on production dynamic data

Abstract

The invention provides an abnormal high-pressure gas reservoir reserve and productivity evaluation method based on production dynamic data, which comprises the following steps: calculating a gas deviation and pressure correlation formula and a gas isothermal compression coefficient and pressure correlation formula to obtain a gas viscosity and pressure correlation formula; deriving and linearizing the abnormal high-pressure gas reservoir material balance equation to obtain a linear relation balance equation; calculating a flowing bottomhole pressure physical property dynamic set and a standard condition physical property constant set; calculating average formation pressure dynamic data in the gas well production process; calculating dynamic data of horizontal axis values and longitudinal axis values to obtain a gas well production stage dynamic data statistical table; calculating abnormal high-pressure gas reservoir single well control reserves; and determining a gas well productivity equation and predicting the absolute open flow capacity. According to the method, the calculation process is simple and convenient, the required parameters are few, a large amount of time and manpower are saved, the calculation efficiency is improved, and the possibility of large-scale popularization and application is promoted on the basis of ensuring the precision.

Description

Technical Field

[0001] This invention relates to the field of dynamic natural gas reserves and production capacity evaluation technology, and in particular to a method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on dynamic production data. Background Technology

[0002] Reserve calculation and production capacity evaluation are two crucial aspects of gas reservoir development. Reserves form the material basis for gas reservoir development, determining the scale of development, while gas well production capacity is a measure of well extraction efficiency, providing a basis for optimizing development methods. Accurate evaluation of reserves and production capacity is of great theoretical and practical significance for the efficient development of natural gas.

[0003] Natural gas reserve evaluation methods include static and dynamic methods. Static methods, namely the volumetric method, are subject to uncertainties in the delineation of gas-bearing area and the calibration of effective thickness, and are generally used for reserve estimation in the early stages of gas reservoir development. Dynamic methods, on the other hand, generally include the mass balance method, the flow mass balance method, the elastic two-phase method, the unsteady well test method, the production decline method, the typical curve method, and the numerical simulation method. These methods use well test or production data and have higher accuracy, and are generally used to verify the reserves of gas reservoirs.

[0004] Currently, both the mass balance method and the unsteady gauging method require shut-in pressure testing, which affects the continuity of gas well production. The elastic two-phase method assumes that the gas meets the Darcy flow condition. The production decline method is suitable for gas wells entering the constant pressure and production reduction stage. The typical curve method requires the consistency of the seepage model. The numerical simulation method requires many parameters and is cumbersome. The conventional flow mass balance method is based on constant volume gas-driven gas reservoirs and Darcy's law, and adopts... p wf / Z wf ~ Gp Linear slope substitution or correction p / Z ~ G p Linear slope is generally applicable to stable gas wells with low production in constant-volume gas-driven gas reservoirs. It cannot cover the entire stable production stage (by selecting a certain segment of data for fitting), and it has the problems of stringent adaptation conditions and multiple solutions. It cannot be applied to abnormally high-pressure gas reservoirs, and it cannot simultaneously evaluate reserves and gas well production capacity. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on dynamic production data. The calculation process is simple and requires few parameters, which not only saves a lot of time and manpower and improves calculation efficiency, but also promotes the possibility of widespread application while ensuring accuracy.

[0006] To achieve the above objectives, the present invention provides the following solution: a method for evaluating the reserves and production capacity of abnormally high-pressure gas reservoirs based on production dynamic data, comprising: Based on the acquired basic parameters and the original production dynamic data table, the correlation between gas deviation and pressure and the correlation between gas isothermal compressibility coefficient and pressure are calculated. Then, the gas viscosity data are fitted with a fourth-order polynomial to obtain the correlation between gas viscosity and pressure. By differentiating and linearizing the material balance equation of the abnormally high-pressure gas reservoir, a linear equilibrium equation is obtained. Based on the linear equilibrium equation, calculate the dynamic set of bottom hole flowing pressure properties and the standard condition property constant set; Based on the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, calculate the dynamic data of the average formation pressure during the gas well production process. Based on the initial or cyclic values ​​of the exponent of the gas well exponential production capacity equation and the coefficients of the gas well pseudo-pressure form exponential production capacity equation, calculate the dynamic data of the horizontal and vertical axis values ​​to delete and supplement the original production dynamic data table, and obtain the gas well production stage dynamic data statistics table. Based on the aforementioned basic parameters and the statistical table of dynamic data during the gas well production stage, the slope of the linear function, the original formation pressure, and the gas deviation coefficient under the original formation pressure are calculated to determine the controlled reserves of a single well in an abnormally high-pressure gas reservoir. Based on the final values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, the gas well productivity equation is determined and the absolute unobstructed flow rate is predicted.

[0007] Optionally, based on the acquired basic parameters and raw production dynamic data tables, the correlation between gas deviation and pressure, and the correlation between gas isothermal compressibility coefficient and pressure are calculated. Then, a fourth-order polynomial is used to fit the gas viscosity data to obtain the correlation between gas viscosity and pressure, including: The original formation pressure, reservoir temperature, natural gas relative density, pore compressibility coefficient, original water saturation and water isothermal compressibility coefficient are obtained to obtain basic parameters. The measured daily gas production and measured bottom hole flowing pressure as the number of production days are obtained. The measured daily gas production and measured bottom hole flowing pressure are smoothed by function fitting method or moving average method to obtain the original production dynamic data table. Based on the basic parameters and the original production dynamic data table, the pressure calculation interval is obtained. Based on the pressure calculation interval, the gas deviation coefficient is calculated using the gas state equation method. The gas deviation coefficient is fitted using a fourth-order polynomial with an intercept of 1 to obtain the correlation formula between gas deviation and pressure. Substituting the derivative of the gas deviation-pressure correlation equation into the definition of the gas isothermal compressibility coefficient, we obtain the gas isothermal compressibility coefficient-pressure correlation equation; the definition of the gas isothermal compressibility coefficient is: ; in, The isothermal compressibility coefficient of the gas isothermal gas. For pressure, This is the gas deviation coefficient. This is the derivative of the equation relating gas deviation to pressure. Based on the correlation between the gas isothermal compressibility coefficient and pressure, the gas viscosity coefficient data within the pressure calculation range are calculated using the Lee semi-empirical correlation method or the graphical method. Then, based on the gas viscosity coefficient data, the gas viscosity data are fitted using a fourth-order polynomial to obtain the correlation between gas viscosity and pressure.

[0008] Optionally, the material balance equations for abnormally high-pressure gas reservoirs can be differentiated and linearized to obtain linear equilibrium equations, including: The material balance equation for an abnormally high-pressure gas reservoir is obtained, and its calculation expression is as follows: ; in, p This represents the mean formation pressure of an abnormally high-pressure gas reservoir. Z This is the gas deviation coefficient corresponding to the average formation pressure. p i This represents the original formation pressure of the abnormally high-pressure gas reservoir. Z i This represents the gas deviation coefficient corresponding to the original formation pressure. G p This represents the cumulative gas production extracted from an abnormally high-pressure gas reservoir by a gas well. G This refers to the reserves of an abnormally high-pressure gas reservoir. α This is the correction factor for the apparent pressure of abnormally high-pressure gas reservoirs; The expression for the apparent pressure correction factor for abnormally high-pressure gas reservoirs is: ; Based on the material balance equation of the abnormally high-pressure gas reservoir, the derivative of both sides with respect to production time is obtained to obtain the derivative form equation; the calculation expression of the derivative form equation is as follows: ; in, t This refers to the number of days the gas well is producing. The derivative-form equation is simplified to obtain the simplified equation; the computational expression of the simplified equation is: ; Based on the expression for the apparent pressure correction coefficient of the abnormally high-pressure gas reservoir, adjust both sides of the equation. p Taking the derivative, we obtain the equation for the modified coefficient derivative; the calculation expression for the equation for the modified coefficient derivative is: ; Substituting the definition of the gas isothermal compressibility coefficient and the derivative equation of the correction coefficient into the simplified equation, the core flow mass balance equation is obtained; the calculation expression of the core flow mass balance equation is: ; The exponential productivity equation for abnormally high-pressure gas wells, considering the non-Darcy effect, is written as an explicit expression of the pseudo-pressure difference; the calculation expression for the exponential productivity equation for abnormally high-pressure gas wells is as follows: ; in, q This refers to the daily gas production of the gas well. C These are the coefficients of the exponential productivity equation in the pseudo-pressure form for gas wells. μ For pressure p The gas viscosity at the following levels μ sc The gas viscosity at standard pressure. Z sc This is the gas deviation coefficient under standard pressure. p wf This refers to the bottom flow pressure of the gas well. p sc For standard pressure, n The exponent in the gas well exponential productivity equation; The display expression is: ; Taking the time derivative of the explicit expression yields the explicit time derivative equation; the computational expression for the explicit time derivative equation is as follows: ; Substituting the expressed time derivative equation into the core flow mass balance equation, the first balance equation is obtained; the calculation expression of the first balance equation is: ; By aggregating the constants and dynamic data in the first equilibrium equation, a linear equilibrium equation is obtained; the calculation expression of the linear equilibrium equation is as follows: ; ; ; ; in, Y The values ​​on the vertical axis are... X The values ​​are on the horizontal axis. m for Y ~X The slope of a linear function.

[0009] Optionally, based on the linear equilibrium equation, the dynamic set of bottom hole flowing pressure properties and the standard condition property constant set are calculated, including: Based on the linear equilibrium equation, the smoothed bottom hole pressure dynamic data are substituted into the gas deviation and pressure correlation formula to calculate the smoothed bottom hole pressure gas deviation coefficient dynamic data. The smoothed bottom hole pressure dynamic data are then substituted into the gas viscosity and pressure correlation formula to calculate the smoothed bottom hole pressure gas viscosity dynamic data, thus obtaining the bottom hole pressure dynamic property set. Based on the linear equilibrium equation, the standard pressure is substituted into the correlation between gas deviation and pressure to calculate the gas deviation coefficient under standard pressure. Then, the dynamic data of standard pressure is substituted into the correlation between gas viscosity and pressure to calculate the gas viscosity value under standard pressure, thus obtaining the set of standard physical property constants.

[0010] Optionally, based on the initial or cyclic values ​​of the exponent of the gas well's exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, the dynamic data of the average formation pressure during the gas well production process are calculated, including: The pseudo-pressure data within the pressure calculation interval is calculated. With pressure as the horizontal axis and pseudo-pressure as the vertical axis, the pseudo-pressure data is fitted using a fifth-order polynomial to obtain the correlation between pseudo-pressure and pressure. With pseudo-pressure as the horizontal axis and pressure as the vertical axis, the pressure data is fitted using a sixth-order polynomial to obtain the correlation between pressure and pseudo-pressure. Substituting the smoothed bottomhole flowing pressure dynamic data into the pseudo-pressure and pressure correlation formula, the pseudo-bottomhole flowing pressure dynamic data is calculated. Then, substituting the smoothed daily gas production dynamic data, the pseudo-bottomhole flowing pressure dynamic data, and the initial or cyclic values ​​of the exponent of the gas well's exponential production equation and the coefficients of the exponential production equation in the pseudo-pressure form into the pseudo-pressure formula, the initial or cyclic value of the pseudo-pressure is calculated. The calculation expression of the pseudo-pressure formula is as follows: ; Substitute the initial or cyclic value of the pseudo-pressure into the correlation formula between pressure and pseudo-pressure to calculate the initial or cyclic value of the average formation pressure during the production process, and obtain the dynamic data of the average formation pressure.

[0011] Optionally, based on the initial or cyclic values ​​of the exponent of the gas well's exponential productivity equation and the coefficients of the gas well's pseudo-pressure form exponential productivity equation, dynamic data of the horizontal and vertical axis values ​​are calculated to delete and supplement the original production dynamic data table, resulting in a statistical table of dynamic data for the gas well production stage, including: The average formation pressure dynamic data are substituted into the correlation formulas for gas deviation coefficient and pressure, gas isothermal compressibility coefficient and pressure, and gas viscosity and pressure, respectively, to calculate the gas deviation coefficient, gas isothermal compressibility coefficient, and initial or cyclic values ​​of gas viscosity during the gas well production process. Substitute the pore compressibility coefficient, the original water saturation, the water isothermal compressibility coefficient, and the initial or cyclic value of the average formation pressure during gas well production into the expression for the apparent pressure correction coefficient of the abnormal high-pressure gas reservoir, and calculate the initial or cyclic value of the apparent pressure correction coefficient. The dynamic data of the horizontal axis and the vertical axis are calculated using the expressions for the values ​​of the horizontal axis and the vertical axis, respectively. Then, the original production dynamic data table is deleted and supplemented to obtain the dynamic data statistics table of the gas well production stage.

[0012] Optionally, using expressions for the horizontal and vertical axis values ​​respectively, dynamic data for the horizontal and vertical axes values ​​are calculated. Then, the original production dynamic data table is deleted and supplemented to obtain a statistical table of dynamic data for the gas well production stage, including: Substitute the initial or cyclic values ​​of the pore compressibility coefficient, original water saturation, water isothermal compressibility coefficient, gas deviation coefficient, apparent pressure correction coefficient, and gas isothermal compressibility coefficient into the expression for the horizontal axis value, calculate the initial or cyclic values ​​of the horizontal axis value for all days, and obtain the dynamic data of the horizontal axis value. The pressure difference for the day is obtained by subtracting the smoothed bottom-hole pressure for the next day from the smoothed bottom-hole pressure for the current day. The gas production difference for the day is obtained by subtracting the smoothed daily gas production for the next day from the smoothed daily gas production for the current day. The initial or cyclic values ​​of the smoothed bottom-hole pressure, gas deviation coefficient under the smoothed bottom-hole pressure, gas viscosity under the smoothed bottom-hole pressure, pressure difference for the day, smoothed daily gas production for the day, gas production difference for the day, gas viscosity, gas deviation coefficient, and the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficient of the exponential productivity equation in the pseudo-pressure form of the gas well are substituted into the calculation expression of the vertical axis value to calculate the initial or cyclic values ​​of the vertical axis value for all days, thus obtaining the dynamic data of the vertical axis value. Delete the measured daily gas production and measured bottom hole flowing pressure data from the original production dynamic data table, and add the smoothed bottom hole flowing pressure gas deviation coefficient, smoothed bottom hole flowing pressure gas viscosity, average formation pressure during production, gas deviation coefficient, gas isothermal compressibility coefficient, gas viscosity, initial or cyclic value of apparent pressure correction coefficient, horizontal axis dynamic data and vertical axis dynamic data to obtain a gas well production stage dynamic data statistics table.

[0013] Optionally, based on the basic parameters and the dynamic data statistics table of the gas well production stage, the slope of the linear function, the original formation pressure, and the gas deviation coefficient under the original formation pressure are calculated to determine the controlled reserves of a single well in an abnormally high-pressure gas reservoir, including: Based on the dynamic data statistics table of the gas well production stage, a scatter plot is drawn using the dynamic data of the horizontal axis and the dynamic data of the vertical axis. The scatter plot is then fitted with a linear function to obtain the final values ​​of the exponent of the gas well exponential production capacity equation and the coefficients of the exponential production capacity equation in the pseudo-pressure form of the gas well, as well as the slope of the linear function. Based on the aforementioned basic parameters, the gas deviation coefficient under the original formation pressure is calculated using the DRANCHUK-ABOU-KASSEM method, the Standing-Katz lookup method, or the Hall-Yarborough method. Based on the linear function slope, the original formation pressure, and the gas deviation coefficient under the original formation pressure, the controlled reserves of a single well in an abnormally high-pressure gas reservoir are calculated.

[0014] Optionally, based on the final values ​​of the exponents of the gas well's exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, the gas well productivity equation is determined and the absolute unobstructed flow rate is predicted, including: The final values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well are substituted into the exponential productivity equation of the abnormal high pressure gas well to determine the gas well productivity equation. Then, the bottom hole flowing pressure in the determined gas well productivity equation is set to zero to predict the absolute unobstructed flow rate of the gas well. It also includes: determining whether the gas well has two stable production stages during the production process; if so, using the daily gas production of the two stable production stages to further accurately back-calculate the exponential production capacity equation index and the coefficient of the exponential production capacity equation in the pseudo-pressure form of the gas well, and substituting them into the exponential production capacity equation of the abnormal high-pressure gas well to determine the gas well production capacity equation and predict the absolute unobstructed flow rate.

[0015] This invention discloses the following technical effects by providing a method for evaluating the reserves and production capacity of abnormally high-pressure gas reservoirs based on dynamic production data: Based on the material balance equation of abnormally high-pressure gas reservoirs and the gas well production capacity equation considering the non-Darcy effect, through mathematical transformations such as differentiation, a theoretical relationship is established between the rate of change of bottom hole flowing pressure, the rate of change of daily gas production, and the rate of change of average formation pressure under production conditions. For the first time, a flow material balance equation for abnormally high-pressure gas reservoirs is established. By applying the slope of a linear function and basic parameters, the well-controlled reserves of gas wells can be calculated and the gas well production capacity evaluated. This method considers the non-Darcy seepage effect of gas. Through rigorous mathematical derivation, a flow material balance equation for abnormally high-pressure gas reservoirs is established for the first time. It is not limited by stable production or constant pressure operating systems, thus enabling simultaneous evaluation of reserves and production capacity based directly on daily gas production and bottom hole flowing pressure data throughout the entire production stage. The calculation process is simple and requires few parameters, saving significant time and manpower, improving computational efficiency, and promoting the possibility of widespread application while ensuring accuracy.

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the method flow provided in an embodiment of the present invention; Figure 2 A smoothed bottom hole flowing pressure and daily gas production dynamic data diagram provided for an embodiment of the present invention; Figure 3 This is a dynamic data graph of gas deviation coefficient and gas viscosity under smoothed bottom hole flowing pressure provided in an embodiment of the present invention; Figure 4 The simulated pressure and pressure fitting diagram provided for embodiments of the present invention; Figure 5 Pressure and pseudo-pressure fitting diagram provided for embodiments of the present invention; Figure 6 This is a simulated bottom hole flowing pressure dynamic diagram provided in an embodiment of the present invention; Figure 7 The pseudo-pressure dynamic data diagram provided for embodiments of the present invention; Figure 8 A dynamic data diagram of the final determined average formation pressure provided for embodiments of the present invention; Figure 9 The final gas deviation coefficient and gas viscosity dynamic data diagram provided for the embodiments of the present invention; Figure 10 Dynamic data graph of final gas isothermal compressibility and apparent pressure correction coefficient provided for embodiments of the present invention; Figure 11 The final dynamic data graph provided for embodiments of the present invention; Figure 12 This is a scatter plot of linear fitting data for the gas well production stage provided in an embodiment of the present invention. Detailed Implementation

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

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

[0021] like Figure 1 As shown, this invention provides a method for evaluating the reserves and production capacity of abnormally high-pressure gas reservoirs based on production dynamic data, including: Step 1: Based on the acquired basic parameters and raw production dynamic data table, calculate the correlation between gas deviation and pressure, and the correlation between gas isothermal compressibility coefficient and pressure. Then, use a fourth-order polynomial to fit the gas viscosity data to obtain the correlation between gas viscosity and pressure; including: 1.1 Obtain the original formation pressure, reservoir temperature, natural gas relative density, pore compressibility coefficient, original water saturation and water isothermal compressibility coefficient to obtain basic parameters, obtain the measured daily gas production and measured bottom hole flowing pressure as the number of production days, and use the function fitting method or moving average method to smooth the measured daily gas production and measured bottom hole flowing pressure to obtain the original production dynamic data table; 1.2 Based on the basic parameters and the original production dynamic data table, obtain the pressure calculation interval. Based on the pressure calculation interval, calculate the gas deviation coefficient using the gas state equation method. Fit the gas deviation coefficient using a fourth-order polynomial with an intercept of 1 to obtain the correlation formula between gas deviation and pressure. 1.3 Substituting the derivative of the gas deviation versus pressure equation into the definition of the gas isothermal compressibility coefficient, we obtain the gas isothermal compressibility coefficient versus pressure equation; the definition of the gas isothermal compressibility coefficient is: (1); in, The isothermal compressibility coefficient of the gas isothermal gas. For pressure, This is the gas deviation coefficient. This is the derivative of the equation relating gas deviation to pressure. 1.4 Based on the gas isothermal compressibility coefficient and pressure correlation formula, the gas viscosity coefficient data within the pressure calculation interval is calculated using the Lee semi-empirical correlation method or the graphical method. Then, based on the gas viscosity coefficient data, the gas viscosity data is fitted using a fourth-order polynomial to obtain the gas viscosity and pressure correlation formula.

[0022] Step 2: Based on the aforementioned gas viscosity-pressure correlation equation, differentiate and linearize the material balance equation for the abnormally high-pressure gas reservoir to obtain a linear equilibrium equation; including: 2.1 Obtain the material balance equation for the abnormally high-pressure gas reservoir. The calculation expression for the material balance equation of the abnormally high-pressure gas reservoir is as follows: (2); in, p This represents the mean formation pressure of an abnormally high-pressure gas reservoir. Z This is the gas deviation coefficient corresponding to the average formation pressure. p i This represents the original formation pressure of the abnormally high-pressure gas reservoir. Z i This represents the gas deviation coefficient corresponding to the original formation pressure. G p This represents the cumulative gas production extracted from an abnormally high-pressure gas reservoir by a gas well. G This refers to the reserves of an abnormally high-pressure gas reservoir. α The apparent pressure correction factor for abnormally high-pressure gas reservoirs is expressed as follows: (3); In the formula, C p The gas reservoir porosity compressibility is expressed in MPa. -1 ; S wi The bound water saturation of the abnormally high-pressure gas reservoir is a decimal. C w The isothermal compressibility coefficient of water is given in MPa. -1 .

[0023] 2.2 Based on the material balance equation of the abnormally high-pressure gas reservoir, the production times on both sides are differentiated to obtain the derivative form equation; the calculation expression of the derivative form equation is: (4); in, t This refers to the number of days the gas well is producing. 2.3 Due to the gas deviation coefficient Z Both the apparent pressure correction factor α and the pressure are pressure p The function of cumulative gas production from gas wells G p Number of days of production from gas wells t The derivative is equal to the daily gas production of the gas well. q The derivative-form equation is simplified to obtain the simplified equation; the computational expression of the simplified equation is: (5); 2.4 Based on the expression for the apparent pressure correction coefficient of the aforementioned abnormally high-pressure gas reservoir, adjust both sides of the equation... p Taking the derivative, we obtain the equation for the modified coefficient derivative; the calculation expression for the equation for the modified coefficient derivative is: (6); 2.5 Substituting the definition of the gas isothermal compressibility coefficient and the derivative equation of the correction coefficient into the simplified equation, the core flow mass balance equation is obtained; the calculation expression of the core flow mass balance equation is: (7); 2.6 The exponential productivity equation for abnormally high-pressure gas wells, considering the non-Darcy effect, is written as an explicit expression of the pseudo-pressure difference; the calculation expression for the exponential productivity equation for abnormally high-pressure gas wells is as follows: (8); in, q This refers to the daily gas production of the gas well. C These are the coefficients of the exponential productivity equation in the pseudo-pressure form for gas wells. μ For pressure p The gas viscosity at the following levels μ sc The gas viscosity at standard pressure. Z sc This is the gas deviation coefficient under standard pressure. p wf This refers to the bottom flow pressure of the gas well. p sc For standard pressure, n The exponent in the gas well exponential productivity equation is dimensionless and ranges from 0.5 to 1. n When the value equals 1, the gas well exhibits Darcy flow. n The closer the value is to 0.5, the more severe the non-Darcy effect of gas wells becomes; The display expression is: (9); 2.7 The time derivative of the explicit expression is calculated to obtain the explicit time derivative equation; the calculation expression of the explicit time derivative equation is as follows: (10); 2.8 Substituting the expressed time derivative equation into the core flow mass equilibrium equation, the first equilibrium equation is obtained; the calculation expression of the first equilibrium equation is: (11); 2.9 Aggregate the constants and dynamic data in the first equilibrium equation to obtain a linear equilibrium equation; the calculation expression of the linear equilibrium equation is as follows: (12); (13); (14); (15); in, Y The vertical axis value is 10. 4 m 3 / MPa 2 , X The horizontal axis value is in MPa. -1 , m for Y ~ X The slope of a linear function, 10 4 m 3 / MPa.

[0024] Step 3: Based on the aforementioned linear equilibrium equation, calculate the dynamic set of bottom hole flowing pressure properties and the standard condition property constant set; including: 3.1 Based on the linear equilibrium equation, the smoothed bottom hole pressure dynamic data are substituted into the gas deviation and pressure correlation formula to calculate the smoothed bottom hole pressure gas deviation coefficient dynamic data. The smoothed bottom hole pressure dynamic data are then substituted into the gas viscosity and pressure correlation formula to calculate the smoothed bottom hole pressure gas viscosity dynamic data, thus obtaining the bottom hole pressure dynamic property set. 3.2 Based on the aforementioned linear equilibrium equation, the standard pressure... p sc Substituting 0.101325 MPa into the gas deviation-pressure correlation formula, the gas deviation coefficient under standard pressure is calculated, and the standard pressure is then... p sc Substituting the dynamic data of 0.101325 MPa into the correlation formula between gas viscosity and pressure, the gas viscosity value under standard pressure is calculated, and the set of standard physical property constants is obtained.

[0025] Step 4: Based on the initial or cyclic values ​​of the exponent in the gas well's exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form, calculate the dynamic data of the average formation pressure during the gas well production process; including: 4.1 Calculate the pressure calculation range of 0.1 MPa~( p i The pseudo-pressure within +20) MPa ψ data: (16); Using pressure as the horizontal axis and pseudo-pressure as the vertical axis, a fifth-order polynomial is used to fit the pseudo-pressure data to obtain the correlation between pseudo-pressure and pressure. Using pseudo-pressure as the horizontal axis and pressure as the vertical axis, a sixth-order polynomial is used to fit the pressure data to obtain the correlation between pressure and pseudo-pressure. 4.2 Substitute the smoothed bottomhole flowing pressure dynamic data into the pseudo-pressure and pressure correlation formula to calculate the pseudo-bottomhole flowing pressure dynamic data. Then, substitute the smoothed gas well daily gas production dynamic data, the pseudo-bottomhole flowing pressure dynamic data, and the initial or cyclic values ​​of the exponent of the gas well's exponential production capacity equation and the coefficients of the gas well's pseudo-pressure form exponential production capacity equation into the pseudo-pressure formula to calculate the initial or cyclic value of the pseudo-pressure. The calculation expression of the pseudo-pressure formula is as follows: (17); 4.3 Substitute the initial or cyclic value of the pseudo-pressure into the correlation formula between pressure and pseudo-pressure to calculate the initial or cyclic value of the average formation pressure during the production process, and obtain the dynamic data of the average formation pressure.

[0026] Step 5: Based on the initial or cyclic values ​​of the exponent of the gas well's exponential productivity equation and the coefficients of the gas well's pseudo-pressure form exponential productivity equation, calculate the dynamic data of the horizontal and vertical axes to delete and supplement the original production dynamic data table, obtaining a statistical table of dynamic data for the gas well production stage; including: 5.1 Substitute the average formation pressure dynamic data into the correlation formulas for gas deviation coefficient and pressure, gas isothermal compressibility coefficient and pressure, and gas viscosity and pressure, respectively, to calculate the initial or cyclic values ​​of gas deviation coefficient, gas isothermal compressibility coefficient, and gas viscosity during the gas well production process. 5.2 Substitute the pore compressibility coefficient, the original water saturation, the water isothermal compressibility coefficient, and the initial or cyclic value of the average formation pressure during gas well production into the expression for the apparent pressure correction coefficient of the abnormal high-pressure gas reservoir, and calculate the initial or cyclic value of the apparent pressure correction coefficient. 5.3 Using the expressions for the horizontal and vertical axis values ​​respectively, calculate the dynamic data for the horizontal and vertical axes. Then, delete and supplement the original production dynamic data table to obtain a statistical table of dynamic data for the gas well production stage. Specifically, this includes: 5.3.1 Substitute the initial or cyclic values ​​of the pore compressibility coefficient, original water saturation, water isothermal compressibility coefficient, gas deviation coefficient, apparent pressure correction coefficient, and gas isothermal compressibility coefficient into the expression for the horizontal axis value, calculate the initial or cyclic values ​​of the horizontal axis value for all days, and obtain the dynamic data of the horizontal axis value. 5.3.2 By subtracting the smoothed bottom-hole flowing pressure of the following day from the smoothed bottom-hole flowing pressure of the current day, the flowing pressure difference of the day is obtained. By subtracting the smoothed daily gas production of the following day from the smoothed daily gas production of the current day, the gas production difference of the day is obtained. The initial or cyclic values ​​of the smoothed bottom-hole flowing pressure, the gas deviation coefficient under the smoothed bottom-hole flowing pressure, the gas viscosity under the smoothed bottom-hole flowing pressure, the flowing pressure difference of the day, the smoothed daily gas production of the day, the gas production difference of the day, the gas viscosity, the gas deviation coefficient, and the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficient of the gas well pseudo-pressure form exponential productivity equation are substituted into the calculation expression of the vertical axis value to calculate the initial or cyclic values ​​of the vertical axis value for all days, and obtain the dynamic data of the vertical axis value. 5.3.3 Delete the measured daily gas production and measured bottom hole flowing pressure data from the original production dynamic data table, and add the following data to the table: smoothed bottom hole flowing pressure gas deviation coefficient, smoothed bottom hole flowing pressure gas viscosity, average formation pressure during production, gas deviation coefficient, gas isothermal compressibility coefficient, gas viscosity, initial or cyclic value of apparent pressure correction coefficient, horizontal axis dynamic data, and vertical axis dynamic data. This yields a statistical table of dynamic data for the gas well production stage, as shown in Table 1 below: Table 1. Statistical Table of Dynamic Data During Gas Well Production Stage

[0027] Step 6: Based on the aforementioned basic parameters and the dynamic data statistics table of the gas well production stage, calculate the linear function slope, the original formation pressure, and the gas deviation coefficient under the original formation pressure to calculate the controlled reserves of a single well in the abnormally high-pressure gas reservoir; including: 6.1 Based on the dynamic data statistics table of the gas well production stage, a scatter plot is drawn using the dynamic data of the horizontal axis and the dynamic data of the vertical axis. The scatter plot is fitted with a linear function to obtain the final values ​​of the exponent of the gas well exponential production capacity equation and the coefficients of the exponential production capacity equation in the pseudo-pressure form of the gas well, as well as the slope of the linear function. 6.2 Based on the aforementioned basic parameters, calculate the gas deviation coefficient under the original formation pressure using the DRANCHUK-ABOU-KASSEM method, the Standing-Katz lookup method, or the Hall-Yarborough method; 6.3 Based on the slope of a linear function m Original formation pressure p i Based on the gas deviation coefficient under the original formation pressure, the controlled reserves of a single well in an abnormally high-pressure gas reservoir were calculated. G : (18).

[0028] Step 7: Based on the final values ​​of the exponents in the gas well's exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form, determine the gas well's productivity equation and predict the absolute unobstructed flow rate. This includes: 7.1 Substitute the final values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the gas well pseudo-pressure form exponential productivity equation into the exponential productivity equation of the abnormal high pressure gas well to determine the gas well productivity equation. 7.2 Set the bottomhole flowing pressure in the determined gas well productivity equation to zero and predict the absolute unobstructed flow rate of the gas well; 7.3 Optionally, determine whether the gas well has two stable production stages during the production process. If so, use the daily gas production of the two stable production stages to further accurately back-calculate the exponential capacity equation index and the coefficient of the exponential capacity equation in the pseudo-pressure form of the gas well, so as to determine the gas well capacity equation and predict the absolute unobstructed flow rate.

[0029] Step 7 in detail: By changing n and C The value of is such that the y-intercept of the linear function is 0 and R² is maximized, ultimately yielding . n and C The final value. The final value obtained. n and C Substituting the final value into equation (8), the production capacity equation of the gas well can be determined.

[0030] Selectively, if a gas well has two relatively stable production phases during its production process, the daily gas production of the first phase is... q 1. The daily gas production of the second stage is q 2. Collect smoothed bottom hole flowing pressure dynamic data for both stages. Using the smoothed bottom hole flowing pressure dynamic data from the two stable production stages, repeat steps 4-6. n and C The values ​​are combined into ( q / C ) 1 / n The value of is assumed to be two stages ( q / C ) 1 / n The initial value is adjusted in two stages respectively. q / C ) 1 / n The value of , let ( q / C ) 1 / n = Q This enables each stage Y ~ X The intercept of the linear fitting plot is zero, yielding the respective ( ) of the two stages. q / C ) 1 / n ,Right now( q / C ) 1 / n = Q 1, ( q / C ) 1 / n = Q 2.

[0031] Jointly ( q 1 / C ) 1 / n = Q 1 and ( q 2 / C ) 1 / n = Q 2. We can obtain: (19) Taking the natural logarithm of both sides of equation (19) and rearranging, we can obtain the gas well productivity index. n The calculation formula is: (20) The obtained gas well productivity index n Substitute the value ( q 1 / C ) 1 / n = Q 1 or ( q 2 / C ) 1 / n = Q 2. Solve for the coefficients of the exponential productivity equation for gas wells. C The calculation formula is as follows: (twenty one) Determine the gas well productivity index using formula (20) n The values ​​are used to determine the coefficients of the exponential productivity equation for gas wells using equation (21). C The initial value of .

[0032] Repeat steps 4-6 to fix. n The value, fine-tuned C The value of makes the y-intercept of the linear function 0 and R 2 The highest, ultimately obtained C The final value.

[0033] The final result n and C Substituting the final value into equation (8), the production capacity equation of the gas well can be determined.

[0034] Applying the established gas well productivity equation, the bottom hole flowing pressure is set to the standard pressure. p sc Different mean formation pressures p The absolute unobstructed flow rate of the gas well can be predicted using equation (22).

[0035] (twenty two) In the formula, q AOF For the absolute unobstructed flow rate of gas wells under different mean formation pressures, 10 4 m 3 / d.

[0036] Example 2 A production well in an abnormally high-pressure gas reservoir has a known original formation pressure. p i reservoir temperature T and relative density of natural gas γ g Pore ​​compressibility coefficient C p Original water saturation S wi Isothermal compressibility of water C w Record daily gas production and bottom hole flowing pressure dynamic data during the production process to calculate the well-controlled reserves of the well. G And evaluate the well's productivity.

[0037] 1. Compile and statistically analyze the basic parameters of abnormal high-pressure gas reservoirs, daily gas production of gas wells, and measured bottom hole flowing pressure dynamic data, and perform smoothing processing. Compile and statistically analyze the basic parameters of abnormally high-pressure gas reservoirs, including: original formation pressure. p i reservoir temperature T Natural gas relative density γ g Pore ​​compressibility coefficient C p Original water saturation S wi Isothermal compressibility of water C w As shown in Table 2: Table 2. Statistical Table of Basic Parameters of Abnormal High-Pressure Gas Reservoirs

[0038] Table 3 shows the measured daily gas production of gas wells. q m and measured bottom hole flowing pressure p wfm The dynamic data of production days were used to smooth the measured daily gas production and bottom hole flowing pressure data using a function fitting method, resulting in smoothed dynamic data of daily gas production and bottom hole flowing pressure. (See attached data.) Figure 2 As shown.

[0039] Table 3. Statistical Table of Daily Gas Production and Bottom Hole Flow Pressure Dynamics During the Gas Well Production Stage

[0040] 2. Establish gas deviation coefficient Z Gas isothermal compressibility coefficient C g and gas viscosity μ Correlation between pressure According to the reservoir temperature in Table 1 T Relative density of natural gas γ g The DRANCHUK-ABOU-KASSEM (DAK) method was applied to calculate the gas deviation coefficient data within the pressure range of 0.1 MPa to 120 MPa. A fourth-order polynomial with an intercept of 1 was used to fit the gas deviation coefficient data to obtain the gas deviation coefficients. Z With pressure p The relevant formula is: According to the gas deviation coefficient Z With pressure p The correlation is used to find d. Z / d p The correlation, and Z and d Z / d p Substituting the relevant equation into equation (1), the isothermal compressibility coefficient of the gas is obtained. C g With pressure p The correlation formula.

[0041] Using the Lee semi-empirical correlation method or the graphical method, gas viscosity coefficient data within the pressure range of 0.1 MPa to 120 MPa were obtained. The gas viscosity data were then fitted using a fourth-order polynomial to obtain the gas viscosity. μ With pressure p The correlation formula.

[0042] 3. Derive the material balance equation for the flow of abnormally high-pressure gas reservoirs The mass balance equation for the flow of gas in an abnormally high-pressure reservoir is: or: 4. Calculate the gas deviation coefficient under the smoothed bottom hole flowing pressure. Z wf and gas deviation coefficient μwf Dynamic data Smoothed bottomhole flow pressure p wf Dynamic data substituted into gas deviation coefficient Z With pressure p The correlation formula was used to calculate the gas deviation coefficient under the smoothed bottom hole flowing pressure. Z wf Dynamic data, such as Figure 3 As shown.

[0043] Smoothed bottomhole flow pressure p wf Dynamic data substitution for gas viscosity μ With pressure p The correlation formula was used to calculate the gas viscosity under the smoothed bottom hole flowing pressure. μ wf Dynamic data, such as Figure 3 As shown.

[0044] 5. Calculate the gas deviation coefficient under standard pressure. Z sc and gas deviation coefficient μ sc value Standard pressure p sc =0.101325 MPa Substituted into the gas deviation coefficient Z With pressure p The correlation formula was used to calculate the gas deviation coefficient under standard pressure. Z sc The value is 0.99913.

[0045] Standard pressure p sc =0.101325 MPa dynamic data, substituted into gas viscosity μ With pressure p The correlation formula was used to calculate the gas viscosity under standard pressure. μ sc The value is 0.014649 (mPa·s).

[0046] 6. According to n and C The initial or cyclic value is used to calculate the average formation pressure during the gas well production process. p Dynamic data Using equation (16), the pseudo-pressure in the pressure range of 0.1 MPa to 120 MPa is calculated. ψ data.

[0047] With pressure p The horizontal axis represents the pseudo-pressure. ψ Using a fifth-order polynomial as the vertical axis, a pseudo-pressure is fitted. ψ Data, to derive pseudo-stress ψ With pressure p The related formulas, such as Figure 4 As shown in the formula.

[0048] To simulate pressure ψ The horizontal axis represents pressure. p Using a sixth-order polynomial as the vertical axis, pressure is fitted. p Data, yielding pressure p With simulated pressure ψ The related formulas, such as Figure 5 As shown in the formula.

[0049] Smoothed bottomhole flow pressure p wf Dynamic data input to simulate stress ψ With pressure p Correlation ( Figure 4 The formula in the text is used to calculate the pseudo-bottom hole flowing pressure. ψ wf Dynamic data, such as Figure 6 As shown.

[0050] because n and C The value needs to be tested, but the testing steps are omitted here. Here, we directly show the final determined value. n and C The smoothed daily gas production volume q Dynamic data, simulated bottom hole flowing pressure ψ wf Dynamic data n and C Substituting the final value into equation (17), the pseudo-pressure corresponding to the mean formation pressure is calculated. ψ The final value.

[0051] Taking the second day as an example, the smoothed daily gas production volume for the second day... q =55 (10 4 m 3 / d), simulated wellbore flowing pressure on day 2 ψ wf =3463.542723 (MPa 2 ), n The final value is 0.95 and C The final value = 0.25 (10 4 m 3 / d / (MPa1.9 Substituting into equation (17), the pseudo-pressure corresponding to the average formation pressure on the second day is calculated. ψ The final value is 3744.2413 (MPa) 2 ).

[0052] The pseudo-pressure for all days was calculated using this method. ψ Value, to obtain pseudo-pressure ψ For dynamic data, see Figure 7 As shown.

[0053] The pseudo-pressure corresponding to the mean formation pressure ψ Substituting the final value into the pressure p With simulated pressure ψ The correlation formula was used to calculate the average formation pressure during the production process. p The final value.

[0054] Taking the second day as an example, the pseudo-pressure corresponding to the average formation pressure on the second day is... ψ Substituting the final value into the pressure p With simulated pressure ψ The correlation formula was used to calculate the average formation pressure during the production process. p The final value is 99.461667 (MPa).

[0055] The average formation pressure for all days was calculated using this method. p Value, get p For dynamic data, see Figure 8 As shown.

[0056] 7. According to n and C Calculate the initial value or loop value. X and Y Dynamic data The average formation pressure during the gas well production process p Substituting the final value into the gas deviation coefficient Z With pressure p Correlation formulas, gas isothermal compressibility coefficient C g With pressure p Correlation and gas viscosity μ With pressure p The correlation formulas were used to calculate the gas deviation coefficient during the gas well production process. Z Gas isothermal compressibility coefficient C g and gas viscosity μ The final value.

[0057] Taking the second day as an example, the average formation pressure on the second day... p The final value = 99.461667 (MPa) Substitute into the gas deviation coefficient Z With pressure p Correlation formulas, gas isothermal compressibility coefficient C g With pressure p Correlation and gas viscosity μ With pressure p The correlation formulas were used to calculate the gas deviation coefficient on the second day. Z Gas isothermal compressibility coefficient C g and gas viscosity μ The final values ​​were 1.712488 and 0.00384 (MPa), respectively. -1 ) and 0.041723 (mPa·s).

[0058] The gas deviation coefficient for all days was calculated using this method. Z Gas isothermal compressibility coefficient C g and gas viscosity μ value, Z and μ See dynamic data Figure 9 , C g See dynamic data Figure 10 As shown.

[0059] The pore compressibility coefficients in Table 1 C p Original water saturation S wi Isothermal compressibility of water C w and the mean formation pressure during gas well production. p Substituting the final value into equation (3), the apparent pressure correction factor is calculated. α The final value.

[0060] Taking the second day as an example, the porosity compressibility coefficient in Table 1 is... C p Original water saturation S wi Isothermal compressibility of water C w and the mean formation pressure on the second day pSubstituting the final value of 99.461667 (MPa) into equation (3), the apparent pressure correction factor for the second day is calculated. α The final value is 0.996483.

[0061] The apparent pressure correction factor for all days was calculated using the same method. α Value, such as Figure 10 As shown.

[0062] The pore compressibility coefficients in Table 1 C p Original water saturation S wi Isothermal compressibility of water C w and gas deviation coefficient Z Pressure correction factor α Isothermal compressibility of gases C g Substituting the final value into equation (14), we can calculate... X The final value.

[0063] Taking the second day as an example, the porosity compressibility coefficient in Table 1 is... C p Original water saturation S wi Isothermal compressibility of water C w and the gas deviation coefficient on the second day Z Pressure correction factor α Isothermal compressibility of gases C g Substituting the final value into equation (14), we can calculate... X The final value is 0.006049 (MPa) -1 ).

[0064] Calculate all the days using this method. X Value, get X Dynamic data, such as Figure 11 As shown.

[0065] The smoothed bottom-hole flowing pressure of the current day is subtracted from the smoothed bottom-hole flowing pressure of the following day to obtain the current day's result. - d p wf / d t The value is obtained by subtracting the smoothed daily gas production of the following day from the smoothed daily gas production of the current day. - d q / d t The value, and the smoothed bottom hole flowing pressure for the day.p wf Gas deviation coefficient under smoothed bottom hole flowing pressure Z wf Gas viscosity under smoothed bottom hole flowing pressure μ wf On that day - d p wf / d t Value, smoothed daily gas production q On that day - d q / d t Value, gas viscosity μ Gas deviation coefficient Z , n and C Substitute the initial value or loop value into equation (13) to calculate Y The final value is calculated using this method to determine the number of days. Y Value, get Y Dynamic data.

[0066] Taking day 2 as an example, the smoothed bottom hole flowing pressure on day 3 (92.759824 MPa) is subtracted from the smoothed bottom hole flowing pressure on day 3 (92.786344 MPa) to obtain the value of day 2. - d p wf / d t The value is 0.02652 (MPa), and the daily gas production after smoothing on the second day is 55 (10 4 m 3 / d)) minus the smoothed daily gas production on day 3 (55 (10 4 m 3 / d)) to get the -d of day 2 q / d t The value is 0 (10) 4 m 3 / d 2 ), and smooth the bottom hole flowing pressure on the second day. p wf Gas deviation coefficient under bottom hole flowing pressure after smoothing on the second day Z wf Gas viscosity at bottomhole flowing pressure after smoothing on the second day μ wf Day 2 - d p wf / d t Value, daily gas production after smoothing on the second day q Day 2- d q / d t Value, gas viscosity on the second day μ Gas deviation coefficient on the second day Z , n and C Substituting the final value into equation (13), the value of day 2 is calculated. Y The final value is 20.692745 (10 4 m 3 / MPa 2 ).

[0067] Calculate all the days using this method. Y Value, get Y Dynamic data, such as Figure 11 As shown.

[0068] 8. Drawing Y ~ X Scatter plot, using a linear function to fit the scatter points, to determine n and C The final value and the slope of the linear function m by Y With the vertical axis as the ordinate, X Plot a scatter plot on a Cartesian coordinate system with the x-axis as the horizontal axis. Fit these scatter points with a linear function and change... n and C The value, when n and C The values ​​are 0.95 and 0.25 (10) respectively. 4 m 3 / d / (MPa 1.9 When ), the y-intercept of the linear function is 0 and R 2 The highest, such as Figure 12 As shown, determine the slope of the straight line. m The value is 3424.5708 (10 4 m 3 / MPa).

[0069] 9. Calculate the gas deviation coefficient under the original formation pressure. Z i Original formation pressure p i Substitute the gas deviation coefficient Z With pressure p The correlation formula was used to calculate the original formation pressure. p i Gas deviation coefficient Zi It is 1.71822.

[0070] 7. Calculate the controlled reserves of a single well G slope of the line m The values, original formation pressure p i Gas deviation coefficient under original formation pressure Z i Substituting the numerical values ​​into equation (16), the controlled reserves of a single well are calculated. G The value is 199309.2154 (10 4 m 3 ).

[0071] 8. Determine the gas well productivity equation By changing in step 8 n and C The value of makes the y-intercept of the linear function zero and R 2 The highest, ultimately obtained n and C The final values ​​are 0.95 and 0.25 (10 4 m 3 / d / (MPa 1.9 The final result will be n and C Substituting the final value into equation (8), the production capacity equation of the gas well is determined as follows: Applying the established gas well productivity equation, the bottom hole flowing pressure is set to the standard pressure. p sc Different mean formation pressures p The formula for predicting the absolute unobstructed flow rate of a gas well is: Therefore, this invention provides a method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on dynamic production data. The calculation process is simple and requires few parameters, which not only saves a lot of time and manpower and improves calculation efficiency, but also promotes the possibility of widespread application while ensuring accuracy.

[0072] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0073] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, 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 the present invention.

Claims

1. A method for evaluating the reserves and production capacity of abnormally high-pressure gas reservoirs based on production dynamic data, characterized in that, include: Based on the acquired basic parameters and the original production dynamic data table, the correlation between gas deviation and pressure and the correlation between gas isothermal compressibility coefficient and pressure are calculated. Then, the gas viscosity data are fitted with a fourth-order polynomial to obtain the correlation between gas viscosity and pressure. By differentiating and linearizing the material balance equation of the abnormally high-pressure gas reservoir, a linear equilibrium equation is obtained. Based on the linear equilibrium equation, calculate the dynamic set of bottom hole flowing pressure properties and the standard condition property constant set; Based on the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, calculate the dynamic data of the average formation pressure during the gas well production process. Based on the initial or cyclic values ​​of the exponent of the gas well exponential production capacity equation and the coefficients of the gas well pseudo-pressure form exponential production capacity equation, calculate the dynamic data of the horizontal and vertical axis values ​​to delete and supplement the original production dynamic data table, and obtain the gas well production stage dynamic data statistics table. Based on the aforementioned basic parameters and the statistical table of dynamic data during the gas well production stage, the slope of the linear function, the original formation pressure, and the gas deviation coefficient under the original formation pressure are calculated to determine the controlled reserves of a single well in an abnormally high-pressure gas reservoir. Based on the final values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well, the gas well productivity equation is determined and the absolute unobstructed flow rate is predicted.

2. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 1, characterized in that, Based on the acquired basic parameters and raw production dynamic data tables, the correlation formulas between gas deviation and pressure, and between gas isothermal compressibility coefficient and pressure, are calculated. Then, a fourth-order polynomial is used to fit the gas viscosity data to obtain the correlation formula between gas viscosity and pressure, including: The original formation pressure, reservoir temperature, natural gas relative density, pore compressibility coefficient, original water saturation and water isothermal compressibility coefficient are obtained to obtain basic parameters. The measured daily gas production and measured bottom hole flowing pressure as the number of production days are obtained. The measured daily gas production and measured bottom hole flowing pressure are smoothed by function fitting method or moving average method to obtain the original production dynamic data table. Based on the basic parameters and the original production dynamic data table, the pressure calculation interval is obtained. Based on the pressure calculation interval, the gas deviation coefficient is calculated using the gas state equation method. The gas deviation coefficient is fitted using a fourth-order polynomial with an intercept of 1 to obtain the correlation formula between gas deviation and pressure. Substituting the derivative of the gas deviation-pressure correlation equation into the definition of the gas isothermal compressibility coefficient, we obtain the gas isothermal compressibility coefficient-pressure correlation equation; the definition of the gas isothermal compressibility coefficient is: ； in, The isothermal compressibility coefficient of the gas isothermal gas. For pressure, This is the gas deviation coefficient. This is the derivative of the equation relating gas deviation to pressure. Based on the correlation between the gas isothermal compressibility coefficient and pressure, the gas viscosity coefficient data within the pressure calculation range are calculated using the Lee semi-empirical correlation method or the graphical method. Then, based on the gas viscosity coefficient data, the gas viscosity data are fitted using a fourth-order polynomial to obtain the correlation between gas viscosity and pressure.

3. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 2, characterized in that, Differentiating and linearizing the mass balance equations for abnormally high-pressure gas reservoirs yields linear equilibrium equations, including: The material balance equation for an abnormally high-pressure gas reservoir is obtained, and its calculation expression is as follows: ； in, p This represents the mean formation pressure of an abnormally high-pressure gas reservoir. Z This is the gas deviation coefficient corresponding to the average formation pressure. p i This represents the original formation pressure of the abnormally high-pressure gas reservoir. Z i This represents the gas deviation coefficient corresponding to the original formation pressure. G p This represents the cumulative gas production extracted from an abnormally high-pressure gas reservoir by a gas well. G This refers to the reserves of an abnormally high-pressure gas reservoir. α This is the correction factor for the apparent pressure of abnormally high-pressure gas reservoirs; The expression for the apparent pressure correction factor for abnormally high-pressure gas reservoirs is: ； Based on the material balance equation of the abnormally high-pressure gas reservoir, the derivative of both sides with respect to production time is obtained to obtain the derivative form equation; the calculation expression of the derivative form equation is as follows: ； in, t This refers to the number of days the gas well is producing. The derivative-form equation is simplified to obtain the simplified equation; the computational expression of the simplified equation is: ； Based on the expression for the apparent pressure correction coefficient of the abnormally high-pressure gas reservoir, adjust both sides of the equation. p Taking the derivative, we obtain the equation for the modified coefficient derivative; the calculation expression for the equation for the modified coefficient derivative is: ； Substituting the definition of the gas isothermal compressibility coefficient and the derivative equation of the correction coefficient into the simplified equation, the core flow mass balance equation is obtained; the calculation expression of the core flow mass balance equation is: ； The exponential productivity equation for abnormally high-pressure gas wells, considering the non-Darcy effect, is written as an explicit expression of the pseudo-pressure difference; the calculation expression for the exponential productivity equation for abnormally high-pressure gas wells is as follows: ； in, q This refers to the daily gas production of the gas well. C These are the coefficients of the exponential productivity equation in the pseudo-pressure form for gas wells. μ For pressure p The gas viscosity at the following levels μ sc The gas viscosity at standard pressure. Z sc This is the gas deviation coefficient under standard pressure. p wf This refers to the bottom flow pressure of the gas well. p sc For standard pressure, n The exponent in the gas well exponential productivity equation; The display expression is: ； Taking the time derivative of the explicit expression yields the explicit time derivative equation; the computational expression for the explicit time derivative equation is as follows: ； Substituting the expressed time derivative equation into the core flow mass balance equation, the first balance equation is obtained; the calculation expression of the first balance equation is: ； By aggregating the constants and dynamic data in the first equilibrium equation, a linear equilibrium equation is obtained; the calculation expression of the linear equilibrium equation is as follows: ； ； ； ； in, Y The values ​​on the vertical axis are... X The values ​​are on the horizontal axis. m for Y ~ X The slope of a linear function.

4. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 3, characterized in that, Based on the aforementioned linear equilibrium equation, the dynamic set of bottom hole flowing pressure properties and the standard condition property constant set are calculated, including: Based on the linear equilibrium equation, the smoothed bottom hole pressure dynamic data are substituted into the gas deviation and pressure correlation formula to calculate the smoothed bottom hole pressure gas deviation coefficient dynamic data. The smoothed bottom hole pressure dynamic data are then substituted into the gas viscosity and pressure correlation formula to calculate the smoothed bottom hole pressure gas viscosity dynamic data, thus obtaining the bottom hole pressure dynamic property set. Based on the linear equilibrium equation, the standard pressure is substituted into the correlation between gas deviation and pressure to calculate the gas deviation coefficient under standard pressure. Then, the dynamic data of standard pressure is substituted into the correlation between gas viscosity and pressure to calculate the gas viscosity value under standard pressure, thus obtaining the set of standard physical property constants.

5. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 4, characterized in that, Based on the initial or cyclic values ​​of the exponent in the gas well's exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form, calculate the dynamic data of average formation pressure during the gas well production process, including: The pseudo-pressure data within the pressure calculation interval is calculated. With pressure as the horizontal axis and pseudo-pressure as the vertical axis, the pseudo-pressure data is fitted using a fifth-order polynomial to obtain the correlation between pseudo-pressure and pressure. With pseudo-pressure as the horizontal axis and pressure as the vertical axis, the pressure data is fitted using a sixth-order polynomial to obtain the correlation between pressure and pseudo-pressure. Substituting the smoothed bottomhole flowing pressure dynamic data into the pseudo-pressure and pressure correlation formula, the pseudo-bottomhole flowing pressure dynamic data is calculated. Then, substituting the smoothed daily gas production dynamic data, the pseudo-bottomhole flowing pressure dynamic data, and the initial or cyclic values ​​of the exponent of the gas well's exponential production equation and the coefficients of the exponential production equation in the pseudo-pressure form into the pseudo-pressure formula, the initial or cyclic value of the pseudo-pressure is calculated. The calculation expression of the pseudo-pressure formula is as follows: ； Substitute the initial or cyclic value of the pseudo-pressure into the correlation formula between pressure and pseudo-pressure to calculate the initial or cyclic value of the average formation pressure during the production process, and obtain the dynamic data of the average formation pressure.

6. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 5, characterized in that, Based on the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the gas well pseudo-pressure form exponential productivity equation, dynamic data of the horizontal and vertical axis values ​​are calculated to delete and supplement the original production dynamic data table, resulting in a statistical table of dynamic data for the gas well production stage, including: The average formation pressure dynamic data are substituted into the correlation formulas for gas deviation coefficient and pressure, gas isothermal compressibility coefficient and pressure, and gas viscosity and pressure, respectively, to calculate the gas deviation coefficient, gas isothermal compressibility coefficient, and initial or cyclic values ​​of gas viscosity during the gas well production process. Substitute the pore compressibility coefficient, the original water saturation, the water isothermal compressibility coefficient, and the initial or cyclic value of the average formation pressure during gas well production into the expression for the apparent pressure correction coefficient of the abnormal high-pressure gas reservoir, and calculate the initial or cyclic value of the apparent pressure correction coefficient. The dynamic data of the horizontal axis and the vertical axis are calculated using the expressions for the values ​​of the horizontal axis and the vertical axis, respectively. Then, the original production dynamic data table is deleted and supplemented to obtain the dynamic data statistics table of the gas well production stage.

7. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 6, characterized in that, Using expressions for the horizontal and vertical axis values ​​respectively, dynamic data for the horizontal and vertical axes are calculated. Then, the original production dynamic data table is deleted and supplemented to obtain a statistical table of dynamic data for the gas well production stage, including: Substitute the initial or cyclic values ​​of the pore compressibility coefficient, original water saturation, water isothermal compressibility coefficient, gas deviation coefficient, apparent pressure correction coefficient, and gas isothermal compressibility coefficient into the expression for the horizontal axis value, calculate the initial or cyclic values ​​of the horizontal axis value for all days, and obtain the dynamic data of the horizontal axis value. The pressure difference for the day is obtained by subtracting the smoothed bottom-hole pressure for the next day from the smoothed bottom-hole pressure for the current day. The gas production difference for the day is obtained by subtracting the smoothed daily gas production for the next day from the smoothed daily gas production for the current day. The initial or cyclic values ​​of the smoothed bottom-hole pressure, gas deviation coefficient under the smoothed bottom-hole pressure, gas viscosity under the smoothed bottom-hole pressure, pressure difference for the day, smoothed daily gas production for the day, gas production difference for the day, gas viscosity, gas deviation coefficient, and the initial or cyclic values ​​of the exponent of the gas well exponential productivity equation and the coefficient of the exponential productivity equation in the pseudo-pressure form of the gas well are substituted into the calculation expression of the vertical axis value to calculate the initial or cyclic values ​​of the vertical axis value for all days, thus obtaining the dynamic data of the vertical axis value. Delete the measured daily gas production and measured bottom hole flowing pressure data from the original production dynamic data table, and add the smoothed bottom hole flowing pressure gas deviation coefficient, smoothed bottom hole flowing pressure gas viscosity, average formation pressure during production, gas deviation coefficient, gas isothermal compressibility coefficient, gas viscosity, initial or cyclic value of apparent pressure correction coefficient, horizontal axis dynamic data and vertical axis dynamic data to obtain a gas well production stage dynamic data statistics table.

8. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 7, characterized in that, Based on the aforementioned basic parameters and the statistical table of dynamic data during the gas well production stage, the slope of the linear function, the original formation pressure, and the gas deviation coefficient under the original formation pressure are calculated to determine the controlled reserves of a single well in an abnormally high-pressure gas reservoir, including: Based on the dynamic data statistics table of the gas well production stage, a scatter plot is drawn using the dynamic data of the horizontal axis and the dynamic data of the vertical axis. The scatter plot is then fitted with a linear function to obtain the final values ​​of the exponent of the gas well exponential production capacity equation and the coefficients of the exponential production capacity equation in the pseudo-pressure form of the gas well, as well as the slope of the linear function. Based on the aforementioned basic parameters, the gas deviation coefficient under the original formation pressure is calculated using the DRANCHUK-ABOU-KASSEM method, the Standing-Katz lookup method, or the Hall-Yarborough method. Based on the linear function slope, the original formation pressure, and the gas deviation coefficient under the original formation pressure, the controlled reserves of a single well in an abnormally high-pressure gas reservoir are calculated.

9. The method for evaluating the reserves and production capacity of abnormal high-pressure gas reservoirs based on production dynamic data according to claim 8, characterized in that, Based on the final values ​​of the exponents in the gas well exponential productivity equation and the coefficients in the gas well pseudo-pressure form exponential productivity equation, the gas well productivity equation is determined and the absolute unobstructed flow rate is predicted, including: The final values ​​of the exponent of the gas well exponential productivity equation and the coefficients of the exponential productivity equation in the pseudo-pressure form of the gas well are substituted into the exponential productivity equation of the abnormal high pressure gas well to determine the gas well productivity equation. Then, the bottom hole flowing pressure in the determined gas well productivity equation is set to zero to predict the absolute unobstructed flow rate of the gas well. It also includes: determining whether the gas well has two stable production stages during the production process; if so, using the daily gas production of the two stable production stages to further accurately back-calculate the exponential production capacity equation index and the coefficient of the exponential production capacity equation in the pseudo-pressure form of the gas well, and substituting them into the exponential production capacity equation of the abnormal high-pressure gas well to determine the gas well production capacity equation and predict the absolute unobstructed flow rate.

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