Prediction method and device for volume scale of natural fracture

Abstract

The invention discloses a natural fracture volume scale prediction method and device. The method comprises the following steps: acquiring basic parameters of gas production of a plurality of developed gas reservoirs in a target area; calculating dynamic reserves of the plurality of developed gas reservoirs according to the basic parameters of the plurality of developed gas reservoirs; according to the dynamic reserves of the developed gas reservoirs, establishing a relation model between the dynamic reserves of the gas reservoirs in the target area and the fracture volume scale; and obtaining the natural fracture volume scale of the target gas reservoir according to the dynamic reserves of the target gas reservoir in the target area and the established relation model of the dynamic reserves of the target gas reservoir in the target area and the fracture volume scale. According to the method, on the basis of considering the correlation between the gas reservoir fracture volume and the dynamic reserves, the fracture volume can be obtained through geological and geophysical researches without consuming a large amount of cost, and the corresponding fracture volume scale can be accurately predicted, so that a good basis is provided for gas reservoir geological modeling, technical policy making and development scheme compiling.

Description

Technical Field

[0001] This invention relates to the field of oil and gas reservoir development technology, and in particular to a method and apparatus for predicting the volume and size of natural fractures. Background Technology

[0002] Natural gas is a mixture of gases, mainly composed of alkanes, that are naturally found in underground strata. Compared with energy sources such as coal and oil, natural gas has advantages such as safety, high calorific value, and cleanliness.

[0003] In recent years, with the rapid growth in natural gas demand and production, shallow, high-quality gas reservoirs have entered the middle and late stages of development, making the development of new natural gas reservoirs increasingly difficult. This is mainly due to the increasing depth of burial and the growing heterogeneity of the reservoirs. Natural fracture development is not only a crucial guarantee for natural gas production but also a significant cause of water intrusion into the reservoir later on. Predicting the volume and size of natural fractures has always been a challenge in gas reservoir development. Generally, geophysical techniques and geomechanical methods are used, which offer relatively high accuracy for shallow gas reservoirs but relatively poor reliability for deep gas reservoirs, and are also more expensive. Summary of the Invention

[0004] In view of the above problems, the present invention is proposed to provide a method and apparatus for predicting the volume scale of natural cracks that overcomes or at least partially solves the above problems.

[0005] In a first aspect, embodiments of the present invention provide a method for predicting the volume size of natural cracks, comprising:

[0006] Obtain basic parameters for gas production from multiple developed gas reservoirs in the target area;

[0007] Based on the basic parameters of the multiple developed gas reservoirs, calculate the dynamic reserves of the multiple developed gas reservoirs;

[0008] Based on the dynamic reserves of the multiple developed gas reservoirs, a model is established to show the relationship between the dynamic reserves of the gas reservoirs in the target area and the fracture volume scale.

[0009] Based on the dynamic reserves of the target gas reservoir in the target area, and the established model relating the dynamic reserves of the target gas reservoir to the fracture volume scale, the volume scale of the natural fractures in the target gas reservoir is obtained.

[0010] In one embodiment, obtaining basic parameters for gas production from multiple developed gas reservoirs in a target area includes:

[0011] The effective compressibility coefficient, cumulative pressure drop, cumulative gas production, gas compressibility factor, and fracture volume size of the multiple developed gas reservoirs are obtained.

[0012] In one embodiment, calculating the dynamic reserves of the plurality of developed gas reservoirs based on their fundamental parameters includes:

[0013] For each developed gas reservoir, plot in a Cartesian coordinate system with X and Y axes. The corresponding coordinates; where G p These are the coordinates on the X-axis. For the Y-axis and G p The corresponding coordinate values;

[0014] Through the Linear regression is performed on each coordinate point to fit the result. The relationship curve is used to determine the slope a and intercept b of the relationship curve;

[0015] Calculate b / a to obtain the dynamic reserves of the developed gas reservoir;

[0016] In the above formula:

[0017] C e The effective compression ratio is given in MPa. –1 ;

[0018] Gp represents the cumulative gas production at a preset time point, in units of 10. 8 m 3 ;

[0019] Δp is the cumulative pressure drop, calculated by subtracting the formation pressure at a certain time point from the original formation pressure, and the unit is MPa;

[0020] Z is the gas compressibility factor;

[0021] G represents dynamic reserves, in units of 10. 8 m 3 .

[0022] In one embodiment, for each developed gas reservoir, the formation pressure p, cumulative gas production Gp, and cumulative pressure drop Δp at multiple time points of the developed gas reservoir are obtained;

[0023] Draw in a Cartesian coordinate system with X and Y axes. The corresponding coordinates, through the Linear regression is performed on each coordinate point to fit the result. The relationship curves specifically include:

[0024] Calculate each time point The value of , and determine And the corresponding coordinates of Gp in a Cartesian coordinate system;

[0025] Linear regression is performed on the coordinates corresponding to multiple time points in a Cartesian coordinate system to fit the developed gas reservoir. The relationship curve.

[0026] In one embodiment, based on the dynamic reserves of the plurality of developed gas reservoirs, a model is established to show the relationship between the dynamic reserves of the gas reservoirs in the target area and the fracture volume size, including:

[0027] Linear regression formula for determining the regression relationship between dynamic gas reservoir reserves and fracture volume in a target area;

[0028] Based on the dynamic reserves of the multiple developed gas reservoirs and the corresponding fracture volume scale of the developed gas reservoirs, the values ​​of the regression parameters in the linear regression formula are determined.

[0029] Based on the calculated values ​​of the regression parameters, the regression relationship model between the dynamic reserves of the gas reservoir in the target area and the fracture volume scale is obtained by substituting them into the linear regression formula.

[0030] In one embodiment, the regression model for the dynamic reserves of the gas reservoir in the target area and the fracture volume size is as follows: G i =f(V i )=αV i +β;

[0031] G i The dynamic reserves of the i-th gas reservoir are expressed in units of 10. 8 m 3 ;

[0032] α is the regression parameter;

[0033] β is the regression parameter;

[0034] V i Let m be the fracture volume of the i-th gas reservoir. 3 .

[0035] In one embodiment, the natural fracture volume of the target gas reservoir is obtained based on the dynamic reserves of the target gas reservoir in the target area and the established model relating the dynamic reserves of the target gas reservoir to the fracture volume size. Specifically, this includes:

[0036] Using the dynamic reserves of the target gas reservoir as a known parameter, and substituting it into the formula of the regression relationship model between the dynamic reserves of the target gas reservoir and the fracture volume scale, the natural fracture volume scale of the target gas reservoir is calculated.

[0037] Secondly, embodiments of the present invention provide a device for predicting the volume scale of natural cracks, comprising:

[0038] The basic parameter acquisition module is used to obtain the basic parameters of gas production from multiple developed gas reservoirs in the target area;

[0039] The dynamic reserves calculation module is used to calculate the dynamic reserves of the multiple developed gas reservoirs based on the basic parameters of the multiple developed gas reservoirs.

[0040] The relational model building module is used to establish a relational model between the dynamic reserves of the gas reservoirs in the target area and the fracture volume scale based on the dynamic reserves of the multiple developed gas reservoirs.

[0041] The natural fracture volume scale calculation module is used to obtain the natural fracture volume scale of the target gas reservoir based on the dynamic reserves of the target gas reservoir in the target area and the established relationship model between the dynamic reserves of the target gas reservoir and the fracture volume scale.

[0042] Thirdly, embodiments of the present invention provide a computing device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for predicting the volume scale of natural cracks as described above.

[0043] Fourthly, embodiments of the present invention provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the aforementioned method for predicting the volume scale of natural cracks.

[0044] Fifthly, embodiments of the present invention provide a computer program product, the computer program product including a computer program, which, when executed by a processor, implements the aforementioned method for predicting the volume scale of natural cracks.

[0045] The beneficial effects of the above-described technical solutions provided in the embodiments of the present invention include at least the following:

[0046] The present invention provides a method and apparatus for predicting the volume and size of natural fractures. This method and apparatus can establish a model of the relationship between the dynamic reserves and fracture volume and size of a target area gas reservoir based on the production data and fracture data of an already operational gas reservoir, taking into account the correlation between the fracture volume and dynamic reserves of the gas reservoir. This eliminates the need to spend a lot of money to obtain the fracture volume through geological and geophysical research. The corresponding fracture volume and size can be accurately predicted based solely on the dynamic reserves of the target gas reservoir, thereby providing a good basis for gas reservoir geological modeling, technology policy formulation, and development plan preparation.

[0047] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0048] 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

[0049] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 This is a flowchart of a method for predicting the volume size of natural cracks in an embodiment of the present invention.

[0051] Figure 2 This is a flowchart of an example from an embodiment of the present invention;

[0052] Figure 3 This is a schematic diagram of the regression relationship curve between dynamic gas reservoir reserves and fracture volume in an embodiment of the present invention;

[0053] Figure 4 This is a schematic diagram of the device for predicting the volume scale of natural cracks in an embodiment of the present invention. Detailed Implementation

[0054] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0055] The inventors of this invention have discovered that accurately predicting the size of natural fractures during the development of deep and ultra-deep gas reservoirs is a common technical challenge, and it is also a key issue in gas reservoir geological modeling and technical policy adjustments.

[0056] This invention provides a method for predicting the volume size of natural cracks, referring to... Figure 1 As shown, it includes:;

[0057] S11. Obtain basic parameters for gas production from multiple developed gas reservoirs in the target area;

[0058] S12. Calculate the dynamic reserves of the multiple developed gas reservoirs based on their basic parameters.

[0059] S13. Based on the dynamic reserves of multiple developed gas reservoirs, establish a model relating dynamic reserves of gas reservoirs in the target area to fracture volume scale.

[0060] S14. Based on the dynamic reserves of the target gas reservoir in the target area and the established model relating the dynamic reserves of the target gas reservoir to the fracture volume scale, the volume scale of the natural fractures in the target gas reservoir is obtained.

[0061] In one embodiment, in step S11 above, there are multiple developed gas reservoirs in the target area. For each developed gas reservoir, basic parameters are collected, including but not limited to the effective compressibility coefficient, cumulative pressure drop, cumulative gas production, gas compressibility factor, and fracture volume size of the multiple developed gas reservoirs.

[0062] The volume of fractures in gas reservoirs can be obtained through geological and geophysical studies.

[0063] In one embodiment, in step S12 above, the dynamic reserves of the multiple developed gas reservoirs are calculated based on the basic parameters of the multiple developed gas reservoirs; specifically, the dynamic reserves of each of the multiple gas reservoirs can be calculated separately using the mass balance equation method, that is, plotting in a Cartesian coordinate system. The slope and intercept of the curve are obtained through curve fitting and linear regression, and the dynamic reserves are calculated using the slope and intercept.

[0064] Specifically, the dynamic reserves of each developed gas reservoir can be calculated using the following method:

[0065] S21. For each developed gas reservoir, draw a diagram in a Cartesian coordinate system with X and Y axes. The corresponding coordinates; where G p These are the coordinates on the X-axis. For the Y-axis and G p The corresponding coordinate values;

[0066] S22, through the Linear regression is performed on each coordinate point to fit the result. The relationship curve is used to determine the slope 'a' and the intercept 'b' of the relationship curve.

[0067] S23. Calculate the value of b / a to obtain the dynamic reserves of the developed gas reservoir.

[0068] In the above formula, the meanings of each parameter are as follows:

[0069] C e The effective compression ratio is given in MPa. –1 ;

[0070] Gp represents the cumulative gas production at a preset time point, in units of 10. 8 m 3 ;

[0071] Δp is the cumulative pressure drop, calculated by subtracting the formation pressure at a certain time point from the original formation pressure, and the unit is MPa;

[0072] Z is the gas compressibility factor;

[0073] G represents dynamic reserves, in units of 10. 8 m 3 .

[0074] In one embodiment, in steps S21 and S22 above, for each developed gas reservoir, formation pressure p, cumulative gas production Gp, and cumulative pressure drop Δp are typically collected at multiple time points. It can be understood that the cumulative gas production gradually increases over time; the more time points of data available, the better the final fitted data will be. The closer the relationship curve is to the actual situation, the better. Of course, with limited data, a curve can also be fitted using data from a small number of time points.

[0075] Specifically, for each developed gas reservoir, the formation pressure p and cumulative gas production Gp at multiple time points are fitted to... The relationship curve can be obtained through the following steps:

[0076] Calculate each time point The value of , and determine And the corresponding coordinates of Gp in a Cartesian coordinate system;

[0077] Linear regression was performed on the coordinates of multiple time points in a Cartesian coordinate system to fit the data of the developed gas reservoir. The relationship curve.

[0078] Through fitting By analyzing the slope and intercept of the relationship curve, the dynamic reserves corresponding to the developed gas reservoir can be calculated.

[0079] In one embodiment, in step S13 above, a model relating the dynamic reserves of the target area gas reservoirs to fracture volume is established based on the dynamic reserves of the plurality of developed gas reservoirs. This can be achieved in the following way:

[0080] 1) Determine the linear regression formula for the regression relationship model between the dynamic reserves of gas reservoirs and the fracture volume scale in the target area;

[0081] Specifically, the regression model for the dynamic reserves of gas reservoirs in the target area and the fracture volume size can be represented by the following formula: G i =f(V i )=αV i +β;

[0082] G i The dynamic reserves of the i-th gas reservoir are expressed in units of 10.8 m 3 ;

[0083] α is the regression parameter;

[0084] β is the regression parameter;

[0085] V i Let m be the fracture volume of the i-th gas reservoir. 3 .

[0086] 2) Based on the dynamic reserves of the multiple developed gas reservoirs and the corresponding fracture volume scale of the developed gas reservoirs, determine the values ​​of the regression parameters in the linear regression formula;

[0087] Based on the dynamic reserves of multiple developed gas reservoirs obtained from the aforementioned steps, and the fracture volume scale corresponding to the developed gas reservoirs in the acquired basic parameters, the values ​​of the regression parameters in step 1 above are determined by linear regression.

[0088] 3) Based on the calculated values ​​of the regression parameters, substitute them into the linear regression formula to obtain the regression relationship model between the dynamic reserves of the gas reservoir in the target area and the fracture volume scale.

[0089] Substituting the values ​​of the linear parameters α and β calculated in step 2) into the linear regression formula, we obtain a regression model of the dynamic reserves of gas reservoirs in the target area and the fracture volume scale.

[0090] With the regression model of the dynamic reserves of the target gas reservoir and the fracture volume scale, in step S14 above, the obtained dynamic reserves of the target gas reservoir are used as known parameters and substituted into the formula of the regression model of the dynamic reserves of the target gas reservoir and the fracture volume scale to calculate the natural fracture volume scale of the target gas reservoir.

[0091] The specific implementation method of the above-mentioned method for predicting the volume scale of a natural crack is illustrated with an example.

[0092] For a fractured gas field in a certain basin, the fracture volume sizes of nine gas reservoirs were obtained through geological and geophysical studies. Based on production and fracture data, the fracture volume size of target gas reservoir A was determined. The specific implementation process is described in [reference needed]. Figure 2 As shown, the specific explanation is as follows:

[0093] Step S101: Determine the basic parameters of the gas reservoir.

[0094] In one embodiment, determining the basic parameters of the gas reservoirs includes determining the effective compressibility coefficient, cumulative pressure drop, cumulative gas production, gas compressibility factor, and fracture volume size of the nine gas reservoirs.

[0095] Step S102: Calculate the dynamic reserves of the gas reservoir.

[0096] Specifically, the dynamic reserves of nine gas reservoirs were calculated using the mass balance equation method. The results were plotted in a Cartesian coordinate system with X and Y axes. Relationship curve, G p These are the coordinates on the X-axis. Given the coordinates on the Y-axis, the slope a and intercept b are obtained through curve fitting and linear regression, and the dynamic reserves are calculated using b / a.

[0097] Specifically, step S102 includes the following steps:

[0098] Obtain the formation pressure p, cumulative gas production Gp, and cumulative pressure drop Δp at n (n > 2) time points;

[0099] There are n time points t1, t2, t3...t n .

[0100] Based on the formation pressure p, cumulative gas production Gp, and cumulative pressure drop Δp at n (n > 2) time points, calculate the values ​​at each of the n time points. Based on multiple time points And cumulative gas production Gp, fit the results Relationship curve;

[0101] Step S103: The dynamic reserves of the nine developed gas reservoirs are obtained by calculating the ratio of intercept to slope, i.e., b / a.

[0102] Specifically, the dynamic reserves of the nine gas reservoirs are 21.5 billion cubic meters, 23.6 billion cubic meters, 45.2 billion cubic meters, 55.6 billion cubic meters, 18.6 billion cubic meters, 23 billion cubic meters, 72 billion cubic meters, 36.6 billion cubic meters and 42.8 billion cubic meters, respectively.

[0103] Step S104: Establish a model for the relationship between dynamic gas reservoir reserves and fracture volume scale, and regress key parameters.

[0104] In one implementation, the determination of the key regression parameters is based on the dynamic reserves and fracture volume data of multiple gas reservoirs, and the parameters α and β are calculated by linear regression.

[0105] Specifically, geological and geophysical studies have yielded fracture volumes of 98,000 cubic meters, 102,000 cubic meters, 242,000 cubic meters, 286,000 cubic meters, 71,000 cubic meters, 92,000 cubic meters, 412,000 cubic meters, 235,000 cubic meters, and 255,000 cubic meters for the nine gas reservoirs.

[0106] Specifically, the dynamic reserves and fracture volumes of the nine gas reservoirs were substituted into G. i =f(V i )=αV iBased on the dynamic reserves and fracture volume data of multiple gas reservoirs, the parameters α and β were calculated by linear regression, and the values ​​of α and β were 0.0627 and -3.7026, respectively.

[0107] Reference Figure 3 This is a scenario example applying the regression curve of dynamic gas reservoir reserves and fracture volume provided by the implementation method of this application for predicting the volume scale of natural fractures based on dynamic gas reservoir reserves.

[0108] Specifically, a model is established to show the relationship between dynamic gas reservoir reserves and fracture volume, as shown in the following mathematical expression:

[0109] G i =f(V i ) = 0.0627V i -3.7026;

[0110] Step S105: Determine the fracture volume size of the target gas reservoir.

[0111] Specifically, based on the basic parameters of the target gas reservoir, the dynamic reserves of the target gas reservoir are calculated to be 29.6 billion cubic meters. By substituting the dynamic reserves of the target gas reservoir into the mathematical expression of the relationship between dynamic reserves and fracture volume, the fracture volume of the target gas reservoir is calculated to be 148,600 cubic meters. This data can provide a good basis for gas reservoir geological modeling, technical policy formulation and adjustment.

[0112] Based on the same inventive concept, embodiments of the present invention also provide an apparatus for predicting the volume size of natural fissures, as described in the following embodiments. Since the principle by which the apparatus solves the problem is similar to that of a method for predicting the volume size of natural fissures, the implementation of an apparatus for predicting the volume size of natural fissures can refer to the implementation of a method for predicting the volume size of natural fissures, and will not be repeated. As used below, the terms "unit" or "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0113] This invention provides an apparatus for predicting the volume size of natural cracks, referring to... Figure 4 As shown, it includes:

[0114] The basic parameter acquisition module 41 is used to obtain the basic parameters of gas production from multiple developed gas reservoirs in the target area.

[0115] The dynamic reserves calculation module 42 is used to calculate the dynamic reserves of the multiple developed gas reservoirs based on the basic parameters of the multiple developed gas reservoirs.

[0116] The relational model establishment module 43 is used to establish a relational model between the dynamic reserves of the gas reservoirs in the target area and the fracture volume scale based on the dynamic reserves of the multiple developed gas reservoirs.

[0117] The natural fracture volume scale calculation module 44 is used to obtain the natural fracture volume scale of the target gas reservoir based on the dynamic reserves of the target gas reservoir in the target area and the established relationship model between the dynamic reserves of the target gas reservoir and the fracture volume scale.

[0118] The above scenario examples verify the method and apparatus for predicting the volume scale of natural fractures provided in this embodiment of the invention. This method and apparatus can establish a model of the relationship between the dynamic reserves and fracture volume scale of a target gas reservoir based on production data and fracture data from already operational gas reservoirs, considering the correlation between fracture volume and dynamic reserves. This eliminates the need for costly geological and geophysical studies to obtain fracture volume; instead, it accurately predicts the corresponding fracture volume scale based solely on the dynamic reserves of the target gas reservoir. This provides a sound basis for gas reservoir geological modeling, technical policy formulation, and development plan development.

[0119] According to an embodiment of the present invention, a computing device is also provided, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the method for predicting the volume scale of natural cracks as described above.

[0120] This invention also provides a computer program product, which includes a computer program that, when executed by a processor, implements the method for predicting the volume scale of natural cracks as described above.

[0121] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage and optical storage) containing computer-usable program code.

[0122] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0123] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0124] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0125] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method of predicting natural fracture volume scale, characterized by, The method comprises the following steps: ； obtaining basic parameters of gas production of a plurality of developed gas reservoirs in a target area; calculating dynamic reserves of the plurality of developed gas reservoirs according to the basic parameters of the plurality of developed gas reservoirs; establishing a relationship model of dynamic reserves and fracture volume scale of gas reservoirs in the target area according to the dynamic reserves of the plurality of developed gas reservoirs; obtaining the natural fracture volume scale of a target gas reservoir in the target area according to the dynamic reserve of the target gas reservoir in the target area and the established relationship model of dynamic reserves and fracture volume scale of gas reservoirs in the target area.

2. The method of claim 1, wherein, The method comprises the following steps: obtaining basic parameters of gas production of a plurality of developed gas reservoirs in a target area, comprising:

3. The method of claim 1, wherein, obtaining the effective compressibility coefficient, cumulative pressure drop, cumulative gas production, gas compressibility factor and fracture volume scale of the plurality of developed gas reservoirs. For each developed gas reservoir, a plane rectangular coordinate system with X, Y as coordinate axes is drawn The corresponding coordinate point; wherein, G p is the coordinate value on the X axis, is the coordinate value on the Y axis corresponding to G p ​ By linear regression on each coordinate point of , a relationship curve of is fitted, and the slope a and the intercept b of the relationship curve are determined. The method comprises the following steps: calculating the dynamic reserves of the developed gas reservoirs by calculating b / a; C e Ceff is the effective compression coefficient in MPa –1 ; Gp is the cumulative gas production at the preset time point, in units of 10 8 m 3 ; In the above formula: Δp is the cumulative pressure drop, which is calculated by subtracting the formation pressure at a certain time point from the original formation pressure, and the unit is MPa; G is the dynamic reserve in units of 10 8 m 3 .

4. The method of claim 3, wherein, Z is the gas compressibility factor; In the plane rectangular coordinate system with X, Y as coordinate axes, the relationship between the X, Y and the corresponding coordinate points is plotted The relationship curve between the X, Y and the corresponding coordinate points is fitted by linear regression on the coordinate points of the X, Y , specifically including:​ The value of each time point is calculated and the corresponding Gp coordinate point in the plane rectangular coordinate system is determined and the corresponding Gp coordinate point in the plane rectangular coordinate system is determined Linear regression is performed on the coordinate points corresponding to the multiple time points in the plane rectangular coordinate system to fit a relationship curve of the developed gas reservoir .

5. The method of claim 1, wherein, For each developed gas reservoir, the formation pressure p, the cumulative gas production Gp and the cumulative pressure drop Δp corresponding to a plurality of time points of the developed gas reservoir are obtained; The method comprises the following steps: determining the linear regression formula of the regression relationship model of the dynamic reserves and the fracture volume scale of the gas reservoirs in the target area; determining the value of the regression parameter in the linear regression formula according to the corresponding relationship between the dynamic reserves of the plurality of developed gas reservoirs and the fracture volume scale corresponding to the developed gas reservoirs; 6. The method of claim 5, wherein, The regression model for the dynamic reserves of gas reservoirs in the target area and the fracture volume scale is given by the following formula: G i =f(V i )=αV i +β; G i Np(i) is the dynamic reserve of the ith gas reservoir, in 10 8 m 3 ; According to the calculated value of the regression parameter, the linear regression formula is substituted to obtain the regression relationship model of the dynamic reserves and the fracture volume scale of the gas reservoirs in the target area. α is the regression parameter; V i Vfi is the fracture volume for the ith gas reservoir, in m 3 .

7. The method of claim 6, wherein, β is the regression parameter; The method comprises the following steps:

8. An apparatus for predicting natural fracture volume scale, comprising: obtaining the natural fracture volume scale of the target gas reservoir in the target area by substituting the obtained dynamic reserve of the target gas reservoir into the formula of the regression relationship model of the dynamic reserves and the fracture volume scale of the gas reservoirs in the target area and calculating. The method comprises the following steps: a basic parameter acquisition module for obtaining basic parameters of gas production of a plurality of developed gas reservoirs in a target area; a dynamic reserve calculation module for calculating dynamic reserves of the plurality of developed gas reservoirs according to the basic parameters of the plurality of developed gas reservoirs; a relationship model establishing module for establishing a relationship model of dynamic reserves and fracture volume scale of gas reservoirs in the target area according to the dynamic reserves of the plurality of developed gas reservoirs; 9. A computing device, comprising: a natural fracture volume scale calculation module for obtaining the natural fracture volume scale of a target gas reservoir in the target area according to the dynamic reserve of the target gas reservoir in the target area and the established relationship model of dynamic reserves and fracture volume scale of gas reservoirs in the target area. The method comprises the following steps: A memory, a processor, and a computer program stored on the memory and executable on the processor, the processor implementing the method for predicting the volume of natural fractures according to any one of claims 1-7 when executing the program.

10. A computer-readable storage medium, characterized in that, The computer readable storage medium stores a computer program, the computer program being executed by the processor to implement the method for predicting the volume of natural fractures according to any one of claims 1-7.

11. A computer program product, characterised in that, The computer program product comprises a computer program, the computer program being executed by the processor to implement the method for predicting the volume of natural fractures according to any one of claims 1-7.

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