Single well control reserve calculation method based on flowing bottomhole pressure data

Abstract

The invention provides a single well controlled reserve calculation method based on flowing bottomhole pressure data, and relates to the technical field of natural gas development. The method comprises the following steps: acquiring flowing bottomhole pressure dynamic data and basic parameters such as original formation pressure, reservoir temperature, natural gas relative density and stable daily gas production in a stable production stage of a gas well; initial flowing bottomhole pressure is determined according to the early flowing bottomhole pressure data, and the pressure square difference is calculated; substituting the dynamic data into a pressure description function and a pressure change rate description function, and calculating to obtain a corresponding dynamic function value; performing linear fitting by using production later-stage data to determine a linear function slope; gas deviation coefficients under the original formation pressure and the stable yield average pressure are calculated according to the reservoir parameters; and finally calculating the single-well controlled reserves in combination with the slope and each parameter. The method solves the problem that dynamic reserves are difficult to assess due to lack of actually measured formation pressure data, and is suitable for reserve verification of stable-yield gas wells in constant-volume gas flooding gas reservoirs.

Description

Technical Field

[0001] This invention relates to the field of natural gas development technology, and in particular to a method for calculating the controlled reserves of a single well based on bottom hole flowing pressure data. Background Technology

[0002] Accurate calculation of gas reservoir reserves is a fundamental step in natural gas development, directly determining the development scale of a gas field and the efficient utilization of resources. Existing gas reservoir reserve evaluation methods are mainly divided into static and dynamic methods. Static methods, such as the volumetric method, are often used for rough estimations in the early stages of development due to uncertainties in determining the gas-bearing area and effective thickness. Dynamic methods, including the mass balance method, the flow mass balance method, and the unsteady gauging method, are frequently used for reserve verification and correction due to their higher accuracy.

[0003] However, existing dynamic evaluation methods have significant limitations in practical applications. The mass balance method and the unsteady gauging method typically require shut-in well testing to obtain the mean formation pressure, which interrupts continuous gas well production and leads to economic losses. The flowing mass balance method theoretically uses bottomhole flowing pressure directly to replace mean formation pressure, but lacks rigorous mathematical derivation, resulting in limited accuracy of the calculation results. Furthermore, the production decline method and numerical simulation methods have limitations in their applicability to different production stages, or require overly complex model parameters. For constant-volume gas-driven reservoirs, how to achieve accurate reserve evaluation using only bottomhole flowing pressure dynamic data during the stable production stage without shutting in the well is a pressing problem in the current technological field. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, the purpose of this invention is to provide a single-well controlled reserve calculation method based on bottom hole flowing pressure data. This invention solves the problems of existing dynamic reserve calculation methods, which require shutting in the well for pressure measurement, affecting production, lacking rigorous mathematical derivation, resulting in insufficient accuracy, and being cumbersome in parameter acquisition, thus limiting applicability.

[0005] To achieve the above objectives, the present invention provides the following solution: A method for calculating controlled reserves in a single well based on bottom hole flowing pressure data includes: To obtain dynamic data of bottom hole flowing pressure during the stable production phase of gas wells, as well as raw formation pressure, reservoir temperature, natural gas relative density, and stable daily gas production related to gas well production; The initial bottom hole pressure is determined based on the early bottom hole pressure data in the bottom hole pressure dynamic data of the gas well during the stable production stage, and the pressure square difference is calculated based on the original formation pressure and the initial bottom hole pressure. Substitute the bottom hole flowing pressure dynamic data and the pressure squared difference into the pressure description function and the pressure rate of change description function, respectively, to calculate the dynamic data of the pressure description function value and the pressure rate of change description function value corresponding to each production time. A scatter plot is drawn with the pressure change rate describing function value as the vertical axis and the pressure describing function value as the horizontal axis. A linear function is then used to fit the dynamic data of the later stage of production in the scatter plot to determine the slope of the linear function. Based on the reservoir temperature and the relative density of natural gas, calculate the gas deviation coefficient under the original formation pressure, and calculate the gas deviation coefficient under the average formation pressure during the stable production stage. Based on the slope of the linear function, the gas deviation coefficient under the original formation pressure, the gas deviation coefficient under the average formation pressure, the original formation pressure, and the stable daily gas production, the controlled reserves of a single well are calculated.

[0006] The present invention discloses the following technical effects: This invention provides a method for calculating controlled reserves in a single well based on bottom-hole flowing pressure data. Based on the material balance equation and well productivity equation of a constant-volume gas-driven reservoir, this invention establishes a theoretical relationship between the rate of change of bottom-hole flowing pressure and the rate of change of average formation pressure under stable production conditions through mathematical transformations such as differentiation. A mathematical model for calculating reservoir reserves based on linear fitting is established. By applying the slope of the linear function and basic parameters, the well-controlled reserves of the gas well can be calculated. This method eliminates the need for shut-in testing of average formation pressure. Through rigorous mathematical derivation, it establishes a theoretical relationship between the rate of change of bottom-hole flowing pressure and the rate of change of average formation pressure, thus enabling accurate reserve evaluation directly based on bottom-hole flowing pressure data. The calculation process is simple and requires few parameters, saving significant time and manpower, improving computational efficiency, and promoting widespread application while maintaining accuracy. Attached Figure Description

[0007] 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.

[0008] Figure 1 A flowchart illustrating a single-well controlled reserves calculation method based on bottom hole flowing pressure data, provided in an embodiment of the present invention; Figure 2 A dynamic diagram of bottom hole flowing pressure during the first stable production stage of a gas well, provided in an embodiment of the present invention; Figure 3 Early bottomhole flowing pressure of the first gas well provided in the embodiments of the present inventionp wf and t Scatter plot of -1; Figure 4 The first gas well stabilization stage provided in the embodiments of the present invention Y ~ X Scatter plot; Figure 5 This is a dynamic diagram of bottom hole flowing pressure during the stable production stage of a second gas well, provided in an embodiment of the present invention. Figure 6 Early bottomhole flowing pressure of the second gas well provided in the embodiments of the present invention p wf and t Scatter plot of -1; Figure 7 The calculations provided for the embodiments of the present invention X and Y Dynamic data graphs; Figure 8 The second gas well stabilization stage provided in the embodiments of the present invention Y ~ X Scatter plot. Detailed Implementation

[0009] 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.

[0010] 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.

[0011] like Figure 1 As shown, this invention provides a method for calculating the controlled reserves of a single well based on bottom hole flowing pressure data, including: Step 100: Obtain dynamic data of bottom hole flowing pressure during the stable production stage of the gas well, as well as raw formation pressure, reservoir temperature, natural gas relative density, and stable daily gas production related to gas well production; Specifically, we need to compile and statistically analyze the basic parameters of constant-volume gas-driven gas reservoirs, including: original formation pressure. p i reservoir temperature T Natural gas relative density γ g Stable daily gas production from the gas well q As shown in Table 1.

[0012] Table 1. Statistical Table of Basic Parameters of Constant Volume Gas Driven Gas Reservoirs

[0013] Bottomhole flowing pressure during the stable production phase of a gas well p wf Dynamic data of production days ， See Table 2 and Figure 2 As shown.

[0014] Table 2. Statistical Table of Bottomhole Flow Pressure Dynamics During the Stable Production Stage of Gas Wells

[0015] Step 200: Determine the initial bottom hole pressure based on the early bottom hole pressure data in the bottom hole pressure dynamic data of the gas well during the stable production stage, and calculate the pressure square difference based on the original formation pressure and the initial bottom hole pressure; Step 300: Substitute the bottom hole flowing pressure dynamic data and the pressure squared difference into the pressure description function and the pressure change rate description function, respectively, to calculate the dynamic data of the pressure description function value and the pressure change rate description function value corresponding to each production time; Step 400: Plot a scatter plot with the pressure change rate describing function value on the vertical axis and the pressure describing function value on the horizontal axis, and fit the dynamic data of the later stage of production in the scatter plot with a linear function to determine the slope of the linear function; Step 500: Calculate the gas deviation coefficient under the original formation pressure based on the reservoir temperature and the relative density of the natural gas, and calculate the gas deviation coefficient under the average formation pressure during the stable production stage; Step 600: Calculate the controlled reserves of a single well based on the slope of the linear function, the gas deviation coefficient under the original formation pressure, the gas deviation coefficient under the average formation pressure, the original formation pressure, and the stable daily gas production.

[0016] Furthermore, the method for determining the initial bottom hole flowing pressure includes: Plot a scatter plot of early bottom hole flowing pressure and production time. A scatter plot is fitted with a linear function to determine the y-intercept of the linear function, where the value of the y-intercept is the initial bottom hole flowing pressure. Specifically, the early bottom hole flowing pressure is plotted in Table 2. p wf and t A scatter plot of -1, using a linear function. p wf =- a ·( t -1)+ p wfiBy fitting these bottom-hole flowing pressure data, the ordinate of the linear function is determined, which is the initial bottom-hole flowing pressure. p wfi The value, such as Figure 3 As shown.

[0017] Apply formula (1) to calculate the pressure square difference Δ during the gas well production process. p 2 .

[0018] (1); In the formula, △ p 2 The pressure squared difference, in MPa 2 ; p The mean formation pressure of a constant-volume gas-driven gas reservoir is expressed in MPa. p wf The bottom-hole flowing pressure of the gas well is in MPa. p i The original formation pressure of the constant-volume gas-driven gas reservoir is expressed in MPa. p wfi The initial bottom hole flowing pressure is given in MPa.

[0019] Due to the daily gas production during the stable production phase of gas wells q Assuming the gas well production capacity remains constant during the production process, according to the gas well production capacity equation, the pressure squared difference Δ p 2 It will remain constant.

[0020] There are generally two types of gas well productivity equations: one is the binomial productivity equation, and the other is the exponential productivity equation. The binomial productivity equation and the exponential productivity equation for gas wells are shown in equation (2) and equation (3), respectively.

[0021] (2); (3); In the formula, p The mean formation pressure of a constant-volume gas-driven gas reservoir is expressed in MPa. p wf The bottom-hole flowing pressure of the gas well is in MPa. q To ensure a stable daily gas production from the gas well, 10 8 m 3 / d; A Darcy's coefficient in the binomial productivity equation for gas wells, in MPa 2 / (10 8 m 3 / d); B The non-Darcy coefficients of the binomial productivity equation for gas wells, in MPa 2 / (10 8 m3 / d) 2 ; C The coefficients of the exponential productivity equation for gas wells are 10. 8 m 3 / d / (MPa 2n ); n This is the exponent of the gas well index production capacity equation, and it is dimensionless.

[0022] The mass balance equation for a constant-volume gas-driven gas reservoir is shown in equation (4): (4); In the formula, p The mean formation pressure of a constant-volume gas-driven gas reservoir is expressed in MPa. Z is the gas deviation coefficient under mean formation pressure, dimensionless; p i The original formation pressure of the constant-volume gas-driven gas reservoir is expressed in MPa. Z i This is the gas deviation coefficient under the original formation pressure, which is dimensionless; G p This represents the cumulative gas production extracted from a gas well from a constant-volume gas-driven reservoir, 10 8 m 3 ; G For the reserves of constant volume gas drive gas reservoirs, 10 8 m 3 .

[0023] For the production time, the left and right sides of equation (4) are respectively... t Taking the derivative, we get: (5); In the formula, t d represents the number of days the gas well is producing.

[0024] Due to gas deviation coefficient Z It's 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 Equation (5) can be further simplified to: (6); Equation (6) can also be written as: (7); For equation (2) or equation (3) regarding production time t Differentiate, since the pressure squared difference Δ during the production process p 2 Since it remains constant, therefore: (8); Substituting equation (8) into equation (7), we get: (9); Taking the reciprocals of both sides of equation (9) and rearranging, we get: (10); Assuming the gas deviation coefficient does not change significantly with pressure, within the pressure drop range Z and d Z / d p Take the average value respectively Z a and (d) Z / d p ) a The average formation pressure is calculated according to equation (1), equation (2) or equation (3). p Substituting into equation (10), the mathematical model for calculating gas reservoir reserves can be obtained as follows: (11); Equation (11) can be written in the following form: (12); In the formula: (13); (14); (15); (16); In the formula, Y for Y Function value, d / MPa 2 ; X for X Function value, MPa -1 ; m for Y ~ X The slope of a linear function, d / MPa; b for Y ~ X The negative value of the y-intercept of a linear function, d / MPa 2 .

[0025] Bottom flow pressure p wf Dynamic data and △ p 2 Substituting the numerical value into formula (14), we can calculate... X The dynamic data is supplemented in Table 2, as shown in Table 3.

[0026] The -d value for the current day is obtained by subtracting the bottom-hole flowing pressure of the next day from the bottom-hole flowing pressure of the current day. p wf / d t The value, and the bottom hole flowing pressure for that day. p wf and the -d of that day p wf / d t Substitute the value into equation (13) to calculate the value for that day. Y The value is calculated using this method to determine the number of days. Y Value, get Y The dynamic data is supplemented in Table 2, as shown in Table 3.

[0027] Table 3. Gas wells in the stable production stage X and Y Calculation Results Table

[0028] by Y With the vertical axis as the ordinate, X Plot a scatter plot in a rectangular coordinate system with the horizontal axis as the x-axis, selecting the later stages of production. Y and X Dynamic data, such as these scattered points are fitted with a linear function. Figure 4 As shown, determine the slope of the straight line. m The value.

[0029] Furthermore, the calculation of the gas deviation coefficient under the original formation pressure includes: Based on any one of the DAK method, the Standing-Katz lookup method, or the HY method, calculate the gas deviation coefficient under the original formation pressure according to the reservoir temperature and the relative density of natural gas.

[0030] Furthermore, the calculation of the gas deviation coefficient under the average formation pressure during the stable production stage includes: Calculate the pressure descriptive value on the last day of stable production; Based on the average pressure calculation formula, the average pressure during the production stabilization process is calculated according to the pressure description value on the last day of the production stabilization process. Based on any one of the DAK method, the Standing-Katz lookup method, or the HY method, calculate the gas deviation coefficient of the average pressure during the stable production process according to the reservoir temperature and the relative density of natural gas.

[0031] Specifically, according to the reservoir temperature in Table 1 T Relative density of natural gas γ gThe original formation pressure was calculated using the DRANCHUK-ABOU-KASSEM (DAK) method, the Standing-Katz map lookup method, the Hall-Yarborough (HY) method, or the method proposed by Li Xiangfang et al. p i Gas deviation coefficient Z i .

[0032] Find the last day of stable production in Table 3. X Calculate the last day of stable production X -1 The value was calculated, and the average pressure during the stable production process was determined. p a The calculation formula is: p a =( p i + X -1 ) / 2. Based on reservoir temperature T Relative density of natural gas γ g The average pressure during the stable production process can be calculated using methods such as the DAK method, the Standing-Katz chart lookup method, the HY method, or methods proposed by Li Xiangfang et al. p a Gas deviation coefficient Z a .

[0033] Based on equation (15), the formula for calculating the controlled reserves of a single well can be derived, as shown in equation (17).

[0034] (17); slope of the line m The numerical value, the gas deviation coefficient under the original formation pressure Z i Average pressure during stable production p a Gas deviation coefficient Z a and the original formation pressure in Table 1 p i Stable daily gas production from the gas well q Substituting the numerical values ​​into equation (17), the controlled reserves of a single well are calculated. G The value of .

[0035] Furthermore, in a certain gas-carrying reservoir, a well can produce a certain amount of gas per day. q Stable production for 2000 days, known original formation pressure of the gas reservoir. p i reservoir temperatureT Relative density of natural gas γ g Record 2000 days of bottom hole flowing pressure dynamic data to calculate the well-controlled reserves of the well. G .

[0036] Compile and analyze the basic parameters of constant-volume gas-driven gas reservoirs and the dynamic data of bottomhole flowing pressure during the stable production stage of gas wells: Compile and statistically analyze the basic parameters of constant-volume gas drive reservoirs, including: original formation pressure. p i reservoir temperature T Natural gas relative density γ g Stable daily gas production from the gas well q As shown in Table 4.

[0037] Table 4. Statistical Table of Basic Parameters of Constant Volume Gas Driven Gas Reservoirs

[0038] Bottomhole flowing pressure during the stable production phase of a gas well p wf Dynamic data of production days ， See Table 5 and Figure 5 As shown.

[0039] Table 5. Statistical Table of Bottomhole Flow Pressure Dynamics During the Stable Production Stage of Gas Wells

[0040] Calculate the pressure squared difference Δ during gas well production. p 2 : Plot the bottom hole flowing pressure in Table 5 for the first 300 days. p wf and t A scatter plot of -1, using a linear function. p wf =- a ·( t -1)+ p wfi Fit these bottom hole flowing pressure data, such as Figure 6 As shown, the determined linear function is: p wf =-0.0058·( t -1)+18.768, the ordinate of the linear function is determined to be 18.768, which is the initial bottom hole flowing pressure. p wfi The value is 18.768 MPa.

[0041] Apply formula (1) to calculate the pressure square difference Δ during the gas well production process. p2 47.76218 (MPa) 2 ).

[0042] ; Due to the daily gas production during the stable production phase of gas wells q Assuming the gas well production capacity remains constant during the production process, according to the gas well production capacity equation, the pressure squared difference Δ p 2 It will remain constant.

[0043] Derivation of the mathematical model for calculating gas reservoir reserves: The mathematical model for calculating gas reservoir reserves is Equation (11) or Equation (12), respectively: ; ; calculate X and Y Dynamic data: Bottom flow pressure p wf Dynamic data and △ p 2 Substituting the numerical value into formula (14), we can calculate... X The dynamic data is supplemented in Table 5, as shown in Table 6 and Figure 7 As shown.

[0044] Taking the second day as an example, the bottom hole flowing pressure on the second day p wf The pressure difference Δ during gas well production is 18.76603 MPa. p 2 47.76218 (MPa) 2 ), calculate the second day X 0.050005 (MPa) -1 ).

[0045] ; The -d value for the current day is obtained by subtracting the bottom-hole flowing pressure of the next day from the bottom-hole flowing pressure of the current day. p wf / d t The value, and the bottom hole flowing pressure for that day. p wf and the -d of that day p wf / d t Substitute the value into equation (13) to calculate the value for that day. Y The value is calculated using this method to determine the number of days. Y Value, get YThe dynamic data is supplemented in Table 5, as shown in Table 6 and Figure 7 As shown.

[0046] Taking the second day as an example, the bottom hole flowing pressure on the second day p wf The bottom hole flowing pressure was 18.76603 MPa on the third day. p wf The pressure is 18.76018 (MPa). The -d value for day 2 is obtained by subtracting the bottom-hole flowing pressure on day 3 from the bottom-hole flowing pressure on day 2. p wf / d t The value is 0.00585 (MPa / d). Calculate the value for the second day. Y The value is 9.115581 (d / MPa) 2 ).

[0047] ; Table 6. Gas wells in the stable production stage X and Y Calculation Results Table

[0048] draw Y ~ X Scatter plots are generated by fitting a linear function to the scatter points to determine the slope of the linear function. m : by Y With the vertical axis as the ordinate, X Plot a scatter plot in a rectangular coordinate system with the horizontal axis as the x-axis, selecting the later stages of production (days 1700 to 2000). Y and X Dynamic data, such as these scattered points are fitted with a linear function. Figure 8 As shown, determine the slope of the straight line. m The value is 199.84 (d / MPa).

[0049] Calculate the gas deviation coefficient under the original formation pressure Z i and the stable production stage Z a : According to the reservoir temperature in Table 4 T Relative density of natural gas γ g The original formation pressure was calculated using the DRANCHUK-ABOU-KASSEM (DAK) method. p i Gas deviation coefficient Z i It is 0.885826.

[0050] Find the last day of stable production in Table 6, i.e., day 2000. X The value is 0.099852 (MPa). -1 ), calculate the last day of stable production X -1 The value is 10.014779 (MPa), and the average pressure during the stable production process is calculated. p a =( p i + X -1 ) / 2 = (20 + 10.014779) / 2 = 15.00739 (MPa). Based on reservoir temperature T Relative density of natural gas γ g The DAK method was applied to calculate the average pressure during the stable production process. p a Gas deviation coefficient Z a It is 0.880513.

[0051] Calculate the controlled reserves of a single well G : slope of the line m =199.84 (d / MPa), original formation pressure p i Gas deviation coefficient Z i =0.885826, average pressure during stable production p a Gas deviation coefficient Z a =0.880513 and the original formation pressure in Table 4 p i =20 (MPa) and stable daily gas production of the gas well q =0.00033 (10 8 m 3 Substituting / d) into equation (17), the single-well controlled reserves of the gas well are calculated. G 1.311033 (10 8 m 3 ).

[0052] .

[0053] 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.

[0054] 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 single well controlled reserve calculation method based on bottom hole pressure data, characterized by, The method comprises the following steps: obtaining the well bottom flowing pressure dynamic data of the stable production stage of the gas well and the original formation pressure, reservoir temperature, relative density of natural gas and stable daily gas production related to the gas well; determining the initial well bottom flowing pressure according to the early well bottom flowing pressure data in the well bottom flowing pressure dynamic data of the stable production stage of the gas well and calculating the pressure square difference according to the original formation pressure and the initial well bottom flowing pressure; substituting the well bottom flowing pressure dynamic data and the pressure square difference into the pressure description function and the pressure change rate description function respectively to calculate the dynamic data of the pressure description function value and the pressure change rate description function value corresponding to each production time; plotting a scatter plot with the pressure change rate description function value as the vertical axis and the pressure description function value as the horizontal axis and fitting the late production dynamic data in the scatter plot with a linear function to determine the slope of the linear function; calculating the gas deviation factor under the original formation pressure according to the reservoir temperature and the relative density of natural gas and calculating the gas deviation factor under the average formation pressure of the stable production stage; calculating the single-well controlled reserves based on the slope of the linear function, the gas deviation factor under the original formation pressure, the gas deviation factor under the average formation pressure, the original formation pressure and the stable daily gas production.

2. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 1, wherein, The method for determining the initial well bottom flowing pressure comprises: plotting a scatter plot of the early well bottom flowing pressure and the production time reaching number; fitting the scatter plot with a linear function to determine the vertical axis intercept of the linear function, wherein the value of the vertical axis intercept is the initial well bottom flowing pressure; the expression of the linear function is: p wf =- a ·( t -1)+ p wfi ； wherein, p wf is the bottom hole flowing pressure, a is the linear function slope, t is the production time, p wfi is the initial bottom hole flowing pressure.

3. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 2, wherein, the calculation expression of the pressure square difference is: ； Among them, △ p 2 The difference in squared pressure; p The mean formation pressure of a constant-volume gas-driven gas reservoir; p wf This refers to the bottom flow pressure of the gas well. p i The original formation pressure of a constant-volume gas-driven gas reservoir; p wfi This represents the initial bottom hole flowing pressure.

4. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 3, wherein, the expressions of the pressure description function and the pressure change rate description function are respectively: ； 。 5. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 3, wherein, The method for calculating the gas deviation factor under the original formation pressure comprises: determining the reservoir temperature and the relative density of natural gas; calculating the gas deviation factor under the original formation pressure according to the reservoir temperature and the relative density of natural gas based on any one of the DAK method, the Standing-Katz chart method and the HY method.

6. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 3, wherein, The method for calculating the gas deviation factor under the average formation pressure of the stable production stage comprises: calculating the pressure description value of the last day of stable production; calculating the average pressure in the stable production process according to the pressure description value of the last day of stable production based on the average pressure calculation formula; calculating the gas deviation factor of the average pressure in the stable production process based on any one of the DAK method, the Standing-Katz chart method and the HY method.

7. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 6, wherein, The expression of the average pressure calculation formula is: p a =( p i + X -1 ) / 2。 8. The single well controlled reserve calculation method based on bottom hole pressure data according to claim 6, wherein, The expression of the single-well controlled reserves is: ； wherein m is the value of the straight line slope, Z i is the gas deviation factor at the initial reservoir pressure, Z a is the gas deviation factor at the average pressure during the stable production, p i is the initial reservoir pressure, q is the daily gas production rate at which the gas well is stable.

Images