Method for calculating productivity of fractured buried hill gas reservoir

Abstract

The invention relates to the technical field of natural gas exploration and development, in particular to a fractured buried hill gas reservoir productivity calculation method which comprises the following steps: S1, collecting data; s2, performing weighting processing on the data; s3, obtaining a weighted fracture equivalent stratum coefficient through the thickness weighted average fracture width, the thickness weighted average fracture density and the thickness weighted average fracture inclination angle; s4, a first productivity calculation formula is introduced, the weighted fracture equivalent stratum coefficient and the total effective thickness of the reservoir are substituted into the first productivity calculation formula, and a second productivity calculation formula is obtained; and S5, regression is carried out on the second productivity calculation formula through the open flow capacity, and a fractured buried hill gas reservoir productivity calculation formula is obtained. According to the method, the fractured gas reservoir equivalent stratum coefficient is used for representing the gas well productivity, the influence of reservoir longitudinal heterogeneity is eliminated, and the productivity calculation result is more accurate.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas exploration and development, and more specifically, to a method for calculating the production capacity of a fractured buried-hill gas reservoir. Background Art

[0002] In recent years, with the continuous deepening of marine natural gas exploration, buried hill gas reservoirs have become a new direction for exploration and development. The lithology of some buried hill gas reservoirs is granite. Such buried hill gas reservoirs are generally full of fractures, with strong heterogeneity and complex gas reservoir development patterns. Since fractures are the main channels for gas seepage, the development morphology of fractures will directly affect the calculation results of gas well production capacity. Therefore, accurately calculating the production capacity of fractured gas reservoirs and guiding the reasonable allocation of gas wells are crucial to delaying water breakthrough in gas fields, improving stable production period and recovery rate.

[0003] At present, the methods for evaluating the productivity of fractured gas reservoirs mainly include analytical and semi-analytical methods, numerical simulation plate methods, and empirical formula methods. Among them, the comparative analysis of existing gas reservoir productivity evaluation methods shows that the analytical and semi-analytical method equations are too complex, and cannot reflect the influence of fracture parameters on productivity for reservoirs with strong heterogeneity; the numerical simulation plate method is limited in parameter characteristic values, and the productivity calculation results have large errors when calculating reservoirs with strong heterogeneity; and the empirical formula method is more sensitive to regression parameters and has poor calculation accuracy. In summary, due to the characteristics of strong reservoir heterogeneity and complex gas reservoir development patterns of fractured buried-hill gas reservoirs, the actual geological characteristics and test conditions of the gas reservoirs usually need to be considered when calculating productivity, while the existing productivity calculation methods are complex and greatly affected by fractures, and the calculation accuracy is poor. Therefore, a new productivity calculation method is needed to improve the accuracy of productivity calculation of fractured buried-hill gas reservoirs with strong heterogeneity. Summary of the invention

[0004] The purpose of the present invention is to overcome the deficiency of the prior art in inaccurate calculation of the production capacity of fractured buried-hill reservoirs with strong reservoir heterogeneity, and to provide a method for calculating the production capacity of fractured buried-hill gas reservoirs, which can accurately calculate the production capacity of fractured buried-hill gas reservoirs.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for calculating the productivity of a fractured buried-hill gas reservoir is provided, comprising the following steps:

[0007] S1. Collecting parameters of reservoir gas wells for capacity calculation, including fracture width, fracture density, fracture inclination, total effective thickness of the reservoir and open flow rate;

[0008] S2, performing weighted average processing on the crack width, the crack density and the crack inclination, to obtain thickness-weighted average crack width, thickness-weighted average crack density and thickness-weighted average crack inclination respectively;

[0009] S3, obtaining a fracture equivalent formation coefficient through the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture dip;

[0010] S4, citing a theoretical formula for gas well productivity as a first productivity calculation formula; substituting the fracture equivalent formation coefficient described in S3 and the total effective thickness of the reservoir described in S1 into the first productivity calculation formula, and obtaining a second productivity calculation formula through the fracture equivalent formation coefficient and the first productivity calculation formula;

[0011] S5. Regress the second capacity calculation formula through the open flow rate to obtain the capacity calculation formula of the fractured buried-hill gas reservoir.

[0012] Through this setting, the weighted fracture equivalent formation coefficient is obtained through the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture inclination to characterize the fracture permeability of the buried hill gas reservoir, thereby reducing the influence of the heterogeneous geological characteristics in the reservoir on the production capacity calculation. Then, the correction coefficient is obtained by regression through the unimpeded flow corresponding to the weighted equivalent bottom coefficient, and then a true and reliable fracture buried hill gas reservoir production capacity calculation formula is derived, which is conducive to improving the accuracy of the production capacity calculation and providing better guidance for production.

[0013] Preferably, in step S2, the first capacity calculation formula is:

[0014]

[0015] In the formula, q sc - surface production of gas wells;

[0016] k——formation permeability;

[0017] h——stratum thickness;

[0018] Z sc ——ground gas deviation factor;

[0019] T sc - ground temperature;

[0020] T——formation temperature;

[0021] p sc - ground pressure;

[0022] r e ——air supply radius;

[0023] r w ——Wellbore radius;

[0024] ψ w ——Pseudo-pressure of bottom hole flow pressure;

[0025] ψ e ——Pseudo-pressure of gas supply boundary.

[0026] Through this setting, for a single medium gas reservoir, we first assume that the bottom layer is a circular equal-thickness mean constant-pressure boundary stratum, ignore the rock compressibility and the gas well skin, and then based on Darcy's law and the mass conservation equation, we can obtain the first production capacity calculation formula when the gas well is in stable production.

[0027] Preferably, in S2, the thickness weighted average crack width calculation formula is:

[0028]

[0029] In the formula, w f ——thickness-weighted average crack width;

[0030] w fi ——Fracture width corresponding to different well depths;

[0031] h i ——Effective thickness of each sublayer.

[0032] Preferably, in S2, the thickness-weighted average crack dip calculation formula is:

[0033]

[0034] In the formula, θ f ——thickness-weighted average crack inclination, rad;

[0035] θ fi ——fracture inclination corresponding to different well depths, rad;

[0036] h i ——Effective thickness of each sublayer, m;

[0037] h——total effective thickness of reservoir, m.

[0038] Preferably, in S2, the thickness weighted average crack density calculation formula is:

[0039]

[0040] In the formula, ρ f ——thickness-weighted average crack density, cracks / m;

[0041] ρ fi ——Fracture density corresponding to different well depths, fractures / m;

[0042] hi——effective thickness of each small layer, m;

[0043] h——total effective thickness of reservoir, m.

[0044] Through this setting, the thickness-weighted average fracture width, the thickness-weighted average fracture density, and the thickness-weighted average fracture inclination can be used to characterize the fracture permeability in the heterogeneous bottom layer, which is beneficial to eliminate the influence of the longitudinal homogeneity of the reservoir and improve the accuracy of the calculation results.

[0045] Preferably, in S2, the weighted fracture equivalent formation coefficient is specifically:

[0046]

[0047] In the formula: (kh) f ——Weighted fracture equivalent formation coefficient, ×10 4 μm 3 ·strip;

[0048] w f ——thickness-weighted average crack width, μm;

[0049] ρ f ——thickness-weighted average crack density, cracks / m;

[0050] θ f ——thickness-weighted average crack inclination, rad;

[0051] h——total effective thickness of reservoir, m.

[0052] Through this setting, the equivalent formation coefficient is obtained based on the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture inclination, and the equivalent formation coefficient of the fractured gas reservoir is used to characterize the heterogeneous geological characteristics of the gas well, thereby eliminating the influence of the longitudinal heterogeneity of the reservoir, making the production capacity calculation formula of the fractured buried-hill gas reservoir more suitable for the production capacity calculation of the fractured buried-hill gas reservoir, and the calculation result is closer to the actual value.

[0053] Preferably, in step S4, the second capacity calculation formula is specifically:

[0054]

[0055] In the formula, q scf ——Surface production of gas wells in fractured gas reservoirs, m 3 / d;

[0056] B 1 - coefficient 1;

[0057] B 2 ——Coefficient 2.

[0058] Preferably, in step S5, the following steps are specifically included:

[0059] S5a, establish an unobstructed flow relationship chart through the unobstructed flow, perform coefficient regression based on the unobstructed flow relationship chart, and obtain B 1 and B 2 ,

[0060] S5b, respectively 1 and B 2 Substitute it into the second capacity calculation formula to obtain the capacity calculation formula for fractured buried-hill gas reservoirs.

[0061] Preferably, in S5a, specifically: statistically obtain the corresponding open flow rate of the fracture gas reservoir under different fracture widths, fracture densities, fracture inclinations, and total effective thickness of the reservoir, take the open flow rate as the ordinate, and the weighted fracture equivalent formation coefficient as the abscissa, establish the open flow rate relationship chart, and use the fitting equation y=B 1 x+B 2 Find coefficient 1 and coefficient 2.

[0062] Preferably, in step S5b, the productivity calculation formula of the fractured buried hill gas reservoir is specifically:

[0063]

[0064] Where q AOF ——Open flow rate of fractured gas reservoir, ×10 4 m 3 / d.

[0065] By adopting the production capacity calculation formula of fractured buried-hill gas reservoirs, the stable production capacity flow of the gas well can be accurately calculated, and the calculated result is not affected by the heterogeneous formation structure and is close to the actual production capacity, which is conducive to predicting the production of heterogeneous geological buried-hill gas reservoirs, thereby providing guidance for mining work.

[0066] Compared with the prior art, the present invention has the following beneficial effects:

[0067] Fractured buried-hill gas reservoir The present invention provides a method for calculating the productivity of a fractured buried-hill gas reservoir, which obtains a weighted fracture equivalent formation coefficient based on the thickness-weighted average fracture width, the thickness-weighted average fracture density, and the thickness-weighted average fracture inclination. It is a new method for calculating the productivity of a gas well by using a weighted fracture equivalent formation coefficient and a corresponding open-flow flow. The method for calculating the productivity of a fractured buried-hill gas reservoir solves the problem of inaccurate results caused by heterogeneous formations when calculating the productivity of a fractured buried-hill gas reservoir in the prior art. Compared with the calculation formula for fractured buried-hill gas reservoirs given in the current public literature, the formula proposed by the present invention uses a weighted fracture equivalent formation coefficient to characterize the productivity of a gas well, eliminates the influence of the longitudinal heterogeneity of the reservoir, is more suitable for the productivity calculation of a buried-hill gas reservoir with heterogeneous geological characteristics, and the calculation result is closer to the actual value. The calculation process of the present invention is clear, and the calculation result can accurately predict the productivity of a fractured buried-hill gas reservoir, providing a scientific and systematic calculation method for calculating the productivity of a gas well in a fractured buried-hill gas reservoir. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic diagram of a process for calculating the productivity of a fractured buried-hill gas reservoir according to the present invention;

[0069] Figure 2 The present invention provides an unobstructed flow relationship chart for a method for calculating the productivity of a fractured buried-hill gas reservoir. DETAILED DESCRIPTION

[0070] The present invention is further described below in conjunction with specific embodiments. The accompanying drawings are only used for exemplary descriptions and are only schematic diagrams rather than physical drawings, and should not be construed as limiting the present invention.

[0071] Example 1

[0072] like Figure 1 to Figure 2 The first embodiment of a method for calculating the productivity of a fractured buried-hill gas reservoir according to the present invention is shown, and includes the following steps:

[0073] S1. Collecting parameters of reservoir gas wells for capacity calculation, including fracture width, fracture density, fracture inclination, total effective thickness of the reservoir and open flow rate;

[0074] S2, performing weighted average processing on the crack width, the crack density and the crack inclination, to obtain thickness-weighted average crack width, thickness-weighted average crack density and thickness-weighted average crack inclination respectively;

[0075] S3, obtaining a fracture equivalent formation coefficient through the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture dip;

[0076] S4, citing a theoretical formula for gas well productivity as a first productivity calculation formula; substituting the fracture equivalent formation coefficient described in S3 and the total effective thickness of the reservoir described in S1 into the first productivity calculation formula, and obtaining a second productivity calculation formula through the fracture equivalent formation coefficient and the first productivity calculation formula;

[0077] S5. Regress the second capacity calculation formula through the open flow rate to obtain the capacity calculation formula of the fractured buried-hill gas reservoir.

[0078] Through this setting, the weighted fracture equivalent formation coefficient is obtained through the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture inclination to characterize the fracture permeability of the buried hill gas reservoir, thereby reducing the influence of the heterogeneous geological characteristics in the reservoir on the production capacity calculation. Then, the correction coefficient is obtained by regression through the unimpeded flow corresponding to the weighted equivalent bottom coefficient, and then a true and reliable fracture buried hill gas reservoir production capacity calculation formula is derived, which is conducive to improving the accuracy of the production capacity calculation and providing better guidance for production.

[0079] As an embodiment of the present invention, in step S4, the first capacity calculation formula is:

[0080]

[0081] In the formula, q sc ——Surface production of gas wells, in m 3 / d;

[0082] k——formation permeability, in μm 2 ;

[0083] h——stratum thickness, in m;

[0084] Z sc ——ground gas deviation factor;

[0085] T sc ——ground temperature, in K;

[0086] T——formation temperature, in K;

[0087] p sc ——ground pressure, in Pa;

[0088] r e ——air supply radius, in m;

[0089] r w ——wellbore radius, in m;

[0090] ψ w ——Pseudo-pressure of bottom hole flow pressure;

[0091] ψe ——Pseudo-pressure of gas supply boundary.

[0092] Through this setting, for a single medium gas reservoir, the bottom layer is first assumed to be a circular equal-thickness mean constant-pressure boundary stratum, and the rock compressibility and gas well skin are ignored. According to Darcy's law and the mass conservation equation, the first production capacity calculation formula for stable gas well production can be obtained.

[0093] As an embodiment of the present invention, in S2, the thickness weighted average crack width calculation formula is:

[0094]

[0095] In the formula, w f ——thickness-weighted average crack width, in μm;

[0096] w fi ——The fracture width corresponding to different well depths, in μm;

[0097] h i ——Effective thickness of each sublayer, in m.

[0098] As an embodiment of the present invention, in S2, the thickness-weighted average crack dip calculation formula is:

[0099]

[0100] In the formula, θ f ——thickness-weighted average crack inclination, in rad;

[0101] θ fi ——The fracture inclination angle corresponding to different well depths, in rad;

[0102] h i ——Effective thickness of each sublayer, in m;

[0103] h——total effective thickness of the reservoir, in m.

[0104] As an embodiment of the present invention, in S2, the thickness weighted average crack density calculation formula is:

[0105]

[0106] In the formula, ρ f ——thickness-weighted average crack density, in cracks / m;

[0107] ρ fi ——Fracture density corresponding to different well depths, in units of fractures / m;

[0108] hi——effective thickness of each sublayer, in m;

[0109] h——total effective thickness of the reservoir, in m.

[0110] Through this setting, the thickness-weighted average fracture width, thickness-weighted average fracture density, and thickness-weighted average fracture inclination angle that characterize fracture permeability can be used to characterize fracture permeability in heterogeneous bottom layers, which is beneficial to eliminating the influence of vertical homogeneity of the reservoir and improving the accuracy of the calculation results.

[0111] As an implementation mode of the present invention, in S3, the weighted fracture equivalent formation coefficient is specifically:

[0112]

[0113] In the formula: (kh) f ——Weighted fracture equivalent formation coefficient, unit is ×10 4 μm 3 ·strip;

[0114] w f ——thickness-weighted average crack width, in μm;

[0115] ρ f ——thickness-weighted average crack density, in cracks / m;

[0116] θ f ——thickness-weighted average crack inclination, in rad;

[0117] h——total effective thickness of the reservoir, in m.

[0118] Through this setting, the equivalent formation coefficient is obtained based on the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture inclination, and the equivalent formation coefficient of the fractured gas reservoir is used to characterize the heterogeneous geological characteristics of the gas well, thereby eliminating the influence of the longitudinal heterogeneity of the reservoir, making the production capacity calculation formula of the fractured buried-hill gas reservoir more suitable for the production capacity calculation of the fractured buried-hill gas reservoir, and the calculation result is closer to the actual value.

[0119] As an embodiment of the present invention, in step S4, the second capacity calculation formula is specifically:

[0120]

[0121] In the formula, q scf ——Surface production of gas wells in fractured gas reservoirs, in m 3 / d;

[0122] B 1 - coefficient 1;

[0123] B 2 ——Coefficient 2.

[0124] Example 2

[0125] The following is a second embodiment of a method for calculating the productivity of a fractured buried-hill gas reservoir according to the present invention. This embodiment is similar to the first embodiment, except that further limitations are imposed on step S5.

[0126] As an embodiment of the present invention, in step S5, the following steps are specifically included:

[0127] S5a, establish an unobstructed flow relationship chart through the unobstructed flow, perform coefficient regression based on the unobstructed flow relationship chart, and obtain B 1 and B 2 ,

[0128] S5b, respectively 1 and B 2 Substitute it into the second capacity calculation formula to obtain the capacity calculation formula for fractured buried-hill gas reservoirs.

[0129] As an embodiment of the present invention, in S5a, specifically: statistically obtain the corresponding open flow rate of the fracture gas reservoir under different fracture widths, fracture densities, fracture inclinations, and total effective thickness of the reservoir, take the open flow rate as the ordinate, and the weighted fracture equivalent formation coefficient as the abscissa, establish the open flow rate relationship chart, and use the fitting equation y=B 1 x+B 2 Find coefficient 1 and coefficient 2.

[0130] As an embodiment of the present invention, in step S6b, the production capacity calculation formula of the fractured buried hill gas reservoir is specifically:

[0131]

[0132] Where q AOF ——Open flow rate of fractured gas reservoir, unit is ×10 4 m 3 / d.

[0133] By adopting the production capacity calculation formula of fractured buried-hill gas reservoirs, the stable production capacity flow of the gas well can be accurately calculated, and the calculated result is not affected by the heterogeneous formation structure and is close to the actual production capacity, which is conducive to predicting the production of heterogeneous geological buried-hill gas reservoirs, thereby providing guidance for mining work.

[0134] Example 3

[0135] The following is a third embodiment of a method for calculating the production capacity of a fractured buried-hill gas reservoir of the present invention. This embodiment is similar to Embodiment 2, except that this embodiment substitutes specific production data of a certain sea area for production capacity calculation.

[0136] After exploration, the following data were obtained for a certain sea area: the directional well encountered a gas layer of 65.87 m in the Mesozoic, the permeability interpreted by the well test was 0.66 mD, the skin coefficient was 30.5, and the open flow relationship map calculated by the "one-point method" was 16.0 × 10 4 m 3 The fracture parameter information interpreted by imaging logging of this well is shown in Table 1, including fracture width, fracture density, and fracture inclination. The production capacity formula of fractured buried-hill gas reservoir is now used to calculate the production capacity of this well and recommend production allocation indicators.

[0137] Table 1 Fracture parameters interpreted by imaging logging of directional wells in a certain sea area

[0138]

[0139] According to the different small-layer crack density, crack width, and crack inclination statistically shown in Table 1, the thickness-weighted average crack density, thickness-weighted average crack width, and thickness-weighted average crack inclination are calculated respectively. The calculation results are shown in Table 2.

[0140] Table 2 Thickness weighted average fracture parameters of directional wells in a certain sea area

[0141]

[0142]

[0143] The open-flow rate of the directional well was calculated to be 17.2×10 4 m 3 / d, compared with the measured open-flow rate of 16.0×10 4 m 3 / d are close to each other, with a relative error of 7.5%.

[0144] q AOF =0.098×33.0 3 ×1.28×cos(1.01)×65.87+1.4558=17.2×10 4 m 3 / d

[0145] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for calculating the productivity of a fractured buried-hill gas reservoir, characterized in that: The following steps are involved: S1. Collecting parameters of reservoir gas wells for capacity calculation, including fracture width, fracture density, fracture inclination, total effective thickness of the reservoir and open flow rate; S2, performing weighted average processing on the crack width, the crack density and the crack inclination, to obtain thickness-weighted average crack width, thickness-weighted average crack density and thickness-weighted average crack inclination respectively; S3, obtaining a weighted fracture equivalent formation coefficient through the thickness-weighted average fracture width, the thickness-weighted average fracture density and the thickness-weighted average fracture dip; S4, citing a theoretical formula for gas well productivity as a first productivity calculation formula, substituting the weighted fracture equivalent formation coefficient described in S3 and the total effective thickness of the reservoir described in S1 into the first productivity calculation formula, to obtain a second productivity calculation formula; S5. Regress the second capacity calculation formula through the open flow rate to obtain the capacity calculation formula of the fractured buried-hill gas reservoir.

2. The method for calculating the productivity of fractured buried-hill gas reservoirs according to claim 1, characterized in that: In step S3, the first capacity calculation formula is: In the formula, q sc - surface production of gas wells; k——formation permeability; h——stratum thickness; Z sc ——ground gas deviation factor; T sc - ground temperature; T——formation temperature; p sc - ground pressure; r e ——air supply radius; r w ——Izutsu radius; ψ w ——Pseudo-pressure of bottom hole flow pressure; ψ e ——Pseudo-pressure of gas supply boundary.

3. The ball pass with a flow blocking portion according to claim 2, characterized in that: The method for calculating the productivity of a fractured buried-hill gas reservoir according to claim 1 is characterized in that, in S2, the thickness-weighted average fracture width calculation formula is: In the formula, w f ——thickness-weighted average crack width; w fi ——Fracture width corresponding to different well depths; h i ——Effective thickness of each sublayer.

4. The method for calculating the productivity of fractured buried-hill gas reservoirs according to claim 3, characterized in that: In S2, the thickness-weighted average crack inclination calculation formula is: In the formula, θ f ——thickness-weighted average crack inclination; θ fi ——Fracture inclination corresponding to different well depths; h i ——Effective thickness of each sub-layer; h——total effective thickness of the reservoir.

5. The method for calculating the productivity of fractured buried-hill gas reservoirs according to claim 4, characterized in that: In S2, the thickness weighted average crack density calculation formula is: In the formula, ρ f ——thickness-weighted average crack density; ρ fi ——Fracture density corresponding to different well depths; hi——effective thickness of each small layer; h——total effective thickness of the reservoir.

6. The method for calculating the productivity of fractured buried-hill gas reservoirs according to claim 5, characterized in that: In S3, the weighted fracture equivalent formation coefficient is specifically: In the formula: (kh) f ——weighted fracture equivalent formation coefficient; w f ——thickness-weighted average crack width; ρ f ——thickness-weighted average crack density; θ f ——thickness-weighted average crack inclination; h——total effective thickness of the reservoir.

7. The method for calculating the productivity of a fractured buried-hill gas reservoir according to claim 6, characterized in that: In step S4, the second capacity calculation formula is specifically: In the formula, q sc f——surface production of gas wells in fractured gas reservoirs; B1——coefficient 1; B2——Coefficient 2.

8. The method for calculating the productivity of a fractured buried-hill gas reservoir according to any one of claims 1 to 7, characterized in that: In step S5, the following steps are specifically included: S5a, establishing an unobstructed flow relationship chart through the unobstructed flow, performing coefficient regression based on the unobstructed flow relationship chart, and obtaining B1 and B2, S5b. Substitute B1 and B2 into the second capacity calculation formula respectively to obtain the capacity calculation formula for the fractured buried-hill gas reservoir.

9. The method for calculating the productivity of a fractured buried-hill gas reservoir according to claim 8, characterized in that: In S5a, specifically: statistically obtain the corresponding open-flow rate of the fractured gas reservoir under different fracture widths, fracture densities, fracture inclinations, and total effective thickness of the reservoir, take the open-flow rate as the vertical coordinate, and the weighted fracture equivalent formation coefficient as the horizontal coordinate, establish the open-flow rate relationship chart, and obtain coefficient 1 and coefficient 2 by fitting the equation y=B1x+B2.

10. The method for calculating the productivity of fractured buried-hill gas reservoirs according to claim 9, characterized in that: In step S5b, the calculation formula for the production capacity of the fractured buried-hill gas reservoir is specifically: Where q AOF : Unobstructed flow rate of fractured gas reservoirs.

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