Fracture-vug type carbonate reservoir integrated acid fracturing productivity prediction method and device

Abstract

The invention relates to the technical field of carbonate reservoir development, and particularly discloses a fracture-vug type carbonate reservoir integrated acid fracturing productivity prediction method and device, and the method comprises the following steps: S1, obtaining reservoir physical property parameters, natural fracture distribution conditions and karst cave development conditions of a reservoir; s2, respectively constructing a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model and a three-dimensional karst cave development condition model; s3, on the basis of the three-dimensional reservoir physical property model, the three-dimensional natural fracture model and the three-dimensional karst cave development condition model, acid fracturing construction pump injection program parameters are combined, and an acid fracturing artificial fracture model is obtained through fitting between simulated injection pressure and actual injection pressure; and S4, carrying out productivity prediction by utilizing the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional karst cave development condition model and the acid fracturing artificial fracture model. According to the method, the geological parameters, the engineering parameters and the acid fracturing artificial fracture construction model are comprehensively considered for productivity prediction, and the productivity prediction accuracy is improved.

Description

Technical Field

[0001] The invention relates to the technical field of carbonate reservoir development, and in particular to a method and device for predicting the integrated acid fracturing production capacity of fracture-cavity carbonate reservoirs. Background Art

[0002] Fracture-cavity carbonate reservoirs usually include pores, caves, and natural fractures, with diverse oil and gas storage spaces and complex reservoir types. Acid fracturing is the main technical means to achieve efficient development of carbonate oil and gas reservoirs. Acid fracturing refers to the use of fracturing fluid to press open an artificial fracture in the oil and gas reservoir through high pressure, and then inject acid to etch the fracture surface. The grooves formed by etching serve as oil and gas flow channels.

[0003] The prediction of carbonate reservoir capacity after acid fracturing is an important part of the optimization of acid fracturing construction parameters. From the perspective of the development of carbonate reservoir acid fracturing capacity prediction methods, most of the existing carbonate reservoir capacity prediction methods are based on machine learning methods and numerical simulation methods. Among them, machine learning methods require a large number of samples for training, and the number of oil and gas wells in the same reservoir is limited, making it difficult to provide the necessary data. In addition, due to the complexity of the carbonate reservoir storage space, the conditions of each oil and gas well are quite different, and the application of machine learning methods is limited; while the numerical simulation method does not consider the influence of the heterogeneity of reservoir porosity and permeability, nor the influence of the development degree of pores, caves, and natural fractures on capacity, and lacks consideration of the influence of artificial fractures formed by acid fracturing on capacity.

[0004] Therefore, it is necessary to provide a new productivity prediction method for fracture-vuggy carbonate reservoirs to improve the prediction accuracy of productivity. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for predicting the production capacity of fracture-cavity carbonate reservoirs by acid fracturing, which comprehensively considers geological parameters, engineering parameters and an acid fracturing artificial fracture construction model to predict production capacity, so as to improve the prediction accuracy of production capacity.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing, comprising the following steps:

[0008] S1. Data acquisition: The reservoir physical property parameters of the reservoir are obtained by testing and analyzing the cores obtained from the reservoir; the distribution of natural fractures and the development of karst caves in the reservoir are obtained by using core analysis and seismic exploration data;

[0009] S2, data processing: pre-processing the reservoir physical property parameters, natural fracture distribution, and cave development obtained in step S1, respectively, to obtain a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model;

[0010] S3, establishing an acid fracturing artificial fracture model: based on the three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model obtained in step S2, combined with the acid fracturing construction pump injection program parameters, the acid fracturing artificial fracture model is obtained by fitting the simulated injection pressure with the actual injection pressure;

[0011] S4. Use the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model obtained in step S2, and the acid fracturing artificial fracture model obtained in step S3 to predict production capacity.

[0012] The three-dimensional reservoir physical property model constructed by the present invention can reflect the influence of heterogeneity of physical property parameters such as porosity and permeability of the reservoir; the three-dimensional natural fracture model and three-dimensional cave development model constructed can reflect the influence of natural fractures and cave development degree on production capacity; the constructed acid fracturing artificial fracture model reflects the influence of artificial fractures formed by acid fracturing on production capacity.

[0013] The invention comprehensively considers the influence of geological parameters (porosity, permeability, geostress, degree of development of pores, caves, natural fractures, etc.), engineering parameters (injection displacement, injection fluid volume, acid fracturing alternation stage, pre-fluid / acid fluid ratio, etc.), and acid fracturing artificial fractures (length, height, number, distribution form), and predicts the production capacity of acid fracturing wells in fracture-cavity carbonate reservoirs, realizes integrated acid fracturing production capacity prediction, and improves the prediction accuracy of production capacity.

[0014] Furthermore, the method further comprises the following steps:

[0015] S5. Compare the predicted capacity in step S4 with the actual capacity. If the difference between the predicted capacity and the actual capacity is less than a threshold value, there is no need to correct the capacity prediction. If the difference between the predicted capacity and the actual capacity is greater than or equal to the threshold value, correct the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model; use the corrected three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model to predict the capacity.

[0016] Furthermore, the capacity forecast correction process is:

[0017] Redo steps S2-S4, reset the interpolation method when establishing the physical property model, reconstruct the continuous three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model; re-simulate the injection pressure and the actual injection pressure to construct the acid fracturing artificial fracture model.

[0018] Furthermore, in step S1, the reservoir physical property parameters include reservoir porosity, permeability, oil and gas saturation, rock Poisson's ratio, rock Young's modulus, vertical stress, horizontal maximum principal stress, horizontal minimum principal stress and pore fluid pressure.

[0019] Furthermore, in step S1, the distribution of natural fractures includes the density, length, height, strike, dip and filling conditions of the natural fractures.

[0020] Furthermore, in step S1, the cave development conditions include the number, size and filling conditions of the caves.

[0021] Furthermore, in step S2, the process of constructing the continuous three-dimensional reservoir physical property model is as follows:

[0022] Discrete reservoir physical property parameters are input into the Petrel software to establish a continuous three-dimensional reservoir physical property model.

[0023] Furthermore, in step S2, the process of constructing the continuous three-dimensional natural fracture model is as follows:

[0024] The distribution of discrete natural fractures is input into the Petrel software, and a continuous three-dimensional natural fracture model is established using the interpolation method.

[0025] Furthermore, in step S2, the process of constructing the continuous three-dimensional cave development model is as follows:

[0026] The discrete karst cave development conditions were input into the Petrel software, and a continuous three-dimensional karst cave development model was established using the interpolation method.

[0027] Furthermore, in step S3, the specific construction process of the acid fracturing artificial fracture model is as follows:

[0028] The three-dimensional reservoir property model, three-dimensional natural fracture model, and three-dimensional cave development model obtained in step S2 are imported into the commercial software Gopher, and the acid fracturing pumping program parameters of the well for which production capacity prediction is required are input. The acid fracturing artificial fracture model is obtained by fitting the simulated injection pressure with the actual injection pressure.

[0029] Furthermore, in step S3, the acid fracturing artificial fracture model includes the length, height, width and number of artificial fractures.

[0030] Furthermore, in step S3, the parameters of the acid fracturing pumping program include injection displacement, injection liquid volume, acid fracturing alternating stages and pre-fluid / acid liquid ratio.

[0031] An integrated acid fracturing capacity prediction device for fracture-cavity carbonate reservoirs, comprising:

[0032] Data acquisition module, used to collect and store reservoir physical parameters, natural fracture distribution and cave development of reservoir;

[0033] The first data processing module is used to pre-process the reservoir physical property parameters, the distribution of natural fractures, and the development of karst caves, and respectively construct a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional karst cave development model;

[0034] The second data processing module is used to construct an acid fracturing artificial fracture model by fitting the simulated injection pressure with the actual injection pressure based on the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model, and the acid fracturing pump injection program parameters;

[0035] The capacity prediction module is used to predict the capacity based on the imported three-dimensional reservoir physical property model, three-dimensional natural fracture model, three-dimensional cave development model and acid fracturing artificial fracture model.

[0036] Furthermore, it also includes:

[0037] A capacity data acquisition module, electrically connected to the capacity prediction module, for collecting and storing the predicted differential capacity and the actual capacity;

[0038] A comparison module, electrically connected to the capacity data acquisition module, for calculating the difference between the predicted capacity difference and the actual capacity;

[0039] The control module determines whether to perform capacity forecast correction by comparing and analyzing the difference calculated by the comparison module and the threshold value; the control module is electrically connected to the comparison module, the first data processing module, the second data processing module and the capacity forecast module. When it is determined that the capacity forecast correction is needed, the control module issues an instruction to redo steps S2-S4, resets the interpolation method when establishing the physical property model, reconstructs a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model; and re-simulates the injection pressure and the actual injection pressure to construct an acid fracturing artificial fracture model.

[0040] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0041] 1. Aiming at the strong heterogeneity of the porosity and permeability of carbonate reservoirs, as well as the actual situation of different development degrees of pores, caves and natural fractures, the prediction method proposed in the present invention realizes the integrated acid fracturing capacity prediction. The so-called integration means comprehensively considering the influence of geological parameters (porosity, permeability, ground stress, development degree of pores, caves and natural fractures, etc.), engineering parameters (injection displacement, injection fluid volume, acid fracturing alternation level, pre-fluid / acid fluid ratio, etc.), and acid fracturing artificial fractures (length, height, number, distribution form), and predicting the capacity of acid fracturing wells in carbonate reservoirs, thereby improving the prediction accuracy of capacity.

[0042] 2. The present invention corrects the capacity prediction model by fitting the injection pressure in the commercial software Gopher with the actual injection pressure, and the difference between the predicted capacity and the actual capacity is within 5%. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0044] Figure 1 A schematic diagram of a three-dimensional porosity model established in an embodiment of the present invention;

[0045] Figure 2 A schematic diagram of a three-dimensional model of Poisson's ratio of reservoir rocks established in an embodiment of the present invention;

[0046] Figure 3 It is a schematic diagram of a three-dimensional model of natural fracture density, length, height, strike, and dip angle established in an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of an acid fracturing artificial fracture model established in an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of a production capacity prediction result according to an embodiment of the present invention;

[0049] Figure 6 The schematic diagram of the integrated acid fracturing capacity prediction device for fracture-cavity carbonate reservoirs of the present invention is shown in FIG. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0051] Embodiment 1:

[0052] A method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing, comprising the following steps:

[0053] S1. Data acquisition: The reservoir physical property parameters of the reservoir are obtained by testing and analyzing the cores obtained from the reservoir; the distribution of natural fractures and the development of karst caves in the reservoir are obtained by using core analysis and seismic exploration data;

[0054] Reservoir physical parameters include reservoir porosity, permeability, oil and gas saturation, rock Poisson's ratio, rock Young's modulus, vertical stress, horizontal maximum principal stress, horizontal minimum principal stress and pore fluid pressure; natural fracture distribution includes density, length, height, strike, dip and filling condition of natural fractures; cave development includes number, size and filling condition of caves.

[0055] S2. Data processing: Preprocess the reservoir physical property parameters, natural fracture distribution, and cave development obtained in step S1 to obtain a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model:

[0056] Constructing a three-dimensional reservoir physical property model:

[0057] The reservoir physical property parameters obtained in step S1 are data from discrete points of a certain well or several wells, and cannot be used directly. It is necessary to use the data on the discrete points to establish a three-dimensional physical property model of the reservoir. In the commercial software Petrel, the reservoir physical property parameters collected in step S1 are input to establish a continuous three-dimensional reservoir physical property model.

[0058] Constructing a 3D natural fracture model:

[0059] The natural fracture distribution information obtained in step S1 is data from discrete points of a certain well, several wells, or a certain area, and cannot be used directly. It is necessary to use the data on the discrete points to establish a three-dimensional natural fracture model. In the commercial software Petrel, the natural fracture distribution information collected in step S1 is input, and a continuous three-dimensional natural fracture model is established using the interpolation method.

[0060] Constructing a three-dimensional cave development model:

[0061] The karst cave development conditions obtained in step S1 are data from discrete points of a certain well, several wells, or a certain area, and cannot be used directly. It is necessary to use the data on the discrete points to establish a three-dimensional karst cave development model. In the commercial software Petrel, the karst cave development conditions collected in step S1 are input, and a continuous three-dimensional karst cave development model is established using the interpolation method.

[0062] S3, establishing an acid fracturing artificial fracture model: based on the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, and the three-dimensional cave development model obtained in step S2, combined with the acid fracturing construction pump injection program parameters, the acid fracturing construction pump injection program parameters include injection displacement, injection liquid volume, acid fracturing alternating series, and pre-fluid / acid liquid ratio, the acid fracturing artificial fracture model is obtained by fitting between the simulated injection pressure and the actual injection pressure;

[0063] The three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model obtained in step S2 are imported into the commercial software Gopher, and the acid fracturing construction pumping program parameters of the well for which production capacity prediction is required are input. The acid fracturing artificial fracture model is obtained by fitting the simulated injection pressure with the actual injection pressure. The acid fracturing artificial fracture model includes the length, height, width, and number of artificial fractures.

[0064] S4, using the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model obtained in step S2, and the acid fracturing artificial fracture model obtained in step S3 to predict production capacity:

[0065] The three-dimensional reservoir physical property model, three-dimensional natural fracture model, three-dimensional cave development model obtained in step S2 and the acid fracturing artificial fracture model obtained in step S3 are imported into the commercial software CMG to predict the production capacity.

[0066] In view of the strong heterogeneity of the porosity and permeability of carbonate reservoirs, as well as the actual situation of different development degrees of pores, caves and natural fractures, the prediction method proposed in this embodiment realizes integrated acid fracturing capacity prediction. The so-called integration means comprehensively considering the influence of geological parameters (porosity, permeability, ground stress, development degree of pores, caves, natural fractures, etc.), engineering parameters (injection displacement, injection fluid volume, acid fracturing alternation level, pre-fluid / acid fluid ratio, etc.), and acid fracturing artificial fractures (length, height, number, distribution form), and predicting the capacity of acid fracturing wells in carbonate reservoirs, thereby improving the prediction accuracy of capacity.

[0067] In a preferred embodiment, the integrated acid fracturing capacity prediction method for fracture-cavity carbonate reservoirs further includes the following steps:

[0068] S5. Compare the predicted capacity in step S4 with the actual capacity. If the difference between the predicted capacity and the actual capacity is less than a threshold value, there is no need to correct the capacity prediction. If the difference between the predicted capacity and the actual capacity is greater than or equal to the threshold value, correct the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model; use the corrected three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model to predict the capacity.

[0069] The process of revising the capacity forecast is as follows:

[0070] Redo steps S2-S4, reset the interpolation method when establishing the physical property model, reconstruct the continuous three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model; re-simulate the injection pressure and the actual injection pressure to construct the acid fracturing artificial fracture model.

[0071] Specifically:

[0072] Capacity forecast model revision:

[0073] After the predicted well has been producing for a period of time, observe the difference between the predicted capacity in step S4 and the actual capacity. If the difference is within 5%, there is no need to correct the capacity forecast, and the result at this time is the final capacity forecast result; if the difference is greater than 5%, the capacity forecast needs to be corrected; the correction method is: redo steps S2-S4, reset the interpolation method when establishing the physical property model in the commercial software Petrel, and re-fit the injection pressure in the commercial software Gopher with the actual injection pressure, until the difference between the predicted capacity and the actual capacity is within 5%.

[0074] Production capacity forecast again:

[0075] When the gap between the predicted capacity and the actual capacity is greater than 5%, the capacity is predicted again using the latest interpolation method used when establishing the physical property model and the fitting parameters between the injection pressure and the actual injection pressure. The result at this time is the final capacity prediction result.

[0076] In this embodiment, the capacity prediction model is corrected by fitting the injection pressure in the commercial software Gopher with the actual injection pressure, and the difference between the predicted capacity and the actual capacity is within 5%.

[0077] In a specific implementation case:

[0078] A method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing, comprising the following steps:

[0079] (1) Obtaining reservoir physical parameters, natural fracture distribution, and cave development

[0080] The physical parameters such as reservoir porosity are obtained, and core analysis and seismic exploration data are used to obtain the distribution of natural fractures and the development of caves in the reservoir, including the density, length, height, strike, dip, and filling of natural fractures, as well as the number, size, and filling of caves. The collected data show that the density of natural fractures is 0.5 / m, the length is between 10-20m, the height is between 8-10m, the strike is between 130°-145°, the dip is between 50-75°, and the natural fractures are partially filled; the number of caves is 10 / m, the size is between 1-3mm, and the caves are partially filled.

[0081] The reservoir physical properties are shown in Table 1:

[0082] Table 1

[0083]

[0084]

[0085] (2) Establishing a three-dimensional reservoir physical property model

[0086] The reservoir physical property parameters obtained in step (1) are data from discrete points of a certain well or several wells and cannot be used directly. It is necessary to use the data from the discrete points to establish a three-dimensional reservoir physical property model. In the commercial software Petrel, the reservoir physical property parameters collected in step (1) are input to establish a continuous three-dimensional reservoir physical property model. The established three-dimensional porosity model and three-dimensional Poisson's ratio model of reservoir rock are as follows: Figure 1 , Figure 2 shown.

[0087] (3) Establish a 3D natural fracture model and a 3D cave development model

[0088] The natural fracture distribution and cave development obtained in step (1) are data from discrete points of a certain well, several wells, or a certain area, and cannot be used directly. It is necessary to use the data from the discrete points to establish a three-dimensional natural fracture model and a three-dimensional cave development model of the reservoir. In the commercial software Petrel, the natural fracture distribution and cave development collected in step (1) are input, and the interpolation method is used to establish a continuous three-dimensional natural fracture model and a three-dimensional cave development model. The established three-dimensional model of natural fracture density, length, height, direction, and inclination is as follows: Figure 3 shown.

[0089] (4) Establishing an acid fracturing artificial fracture model

[0090] The three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model established in steps (2) and (3) are imported into the commercial software Gopher, and the acid fracturing pumping program of the well for which production capacity prediction is required is input. By fitting the simulated injection pressure with the actual injection pressure, the acid fracturing artificial fracture model is obtained, including the length, height, width, and number of artificial fractures. The artificial fracture model is as follows: Figure 4 shown.

[0091] (5) Capacity forecast

[0092] The three-dimensional reservoir physical property model, three-dimensional natural fracture and cave model established in steps (2) and (3), and the acid fracturing artificial fracture model obtained in step (4) are imported into the commercial software CMG to predict the production capacity. The prediction results are as follows: Figure 5 shown.

[0093] (6) Modification of capacity forecast model

[0094] After the predicted well has been producing for a period of time, the gap between the predicted production capacity in step (5) and the actual production capacity is observed, such as Figure 5 As shown in the figure, the first capacity forecast result is significantly different from the actual capacity from January to April 2021. Therefore, the capacity forecast is revised again, that is, steps (2) to (5) are redone, and the interpolation method for establishing the physical property model in the commercial software Petrel is reset, and the injection pressure in the commercial software Gopher is refitted with the actual injection pressure until the gap between the predicted capacity from January to April 2021 and the actual capacity is within 5%.

[0095] (7) Re-forecast of production capacity

[0096] Using the latest interpolation method used to establish the physical property model in step (7) and the fitting parameters between the injection pressure and the actual injection pressure, the production capacity after April 2021 is predicted again, and the second production capacity prediction curve is the final production capacity prediction curve.

[0097] Embodiment 2:

[0098] like Figure 6 As shown, an integrated acid fracturing capacity prediction device for fracture-cavity carbonate reservoirs comprises:

[0099] Data acquisition module, used to collect and store reservoir physical parameters, natural fracture distribution and cave development of reservoir;

[0100] The first data processing module is used to pre-process the reservoir physical property parameters, the distribution of natural fractures, and the development of karst caves, and respectively construct a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional karst cave development model;

[0101] The second data processing module is used to construct an acid fracturing artificial fracture model by fitting the simulated injection pressure with the actual injection pressure based on the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model, and the acid fracturing pump injection program parameters;

[0102] The capacity prediction module is used to predict the capacity based on the imported three-dimensional reservoir physical property model, three-dimensional natural fracture model, three-dimensional cave development model and acid fracturing artificial fracture model.

[0103] In a preferred embodiment, it also includes:

[0104] A capacity data acquisition module, electrically connected to the capacity prediction module, for collecting and storing the predicted differential capacity and the actual capacity;

[0105] A comparison module, electrically connected to the capacity data acquisition module, for calculating the difference between the predicted capacity difference and the actual capacity;

[0106] The control module determines whether to perform capacity forecast correction by comparing and analyzing the difference calculated by the comparison module and the threshold value; the control module is electrically connected to the comparison module, the first data processing module, the second data processing module and the capacity forecast module. When it is determined that the capacity forecast correction is needed, the control module issues an instruction to redo steps S2-S4, resets the interpolation method when establishing the physical property model, reconstructs a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model; and re-simulates the injection pressure and the actual injection pressure to construct an acid fracturing artificial fracture model.

[0107] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing, characterized in that: The following steps are involved: S1. Data acquisition: The reservoir physical property parameters of the reservoir are obtained by testing and analyzing the cores obtained from the reservoir; the distribution of natural fractures and the development of karst caves in the reservoir are obtained by using core analysis and seismic exploration data; S2, data processing: pre-processing the reservoir physical property parameters, natural fracture distribution, and cave development obtained in step S1, respectively, to obtain a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model; S3, establishing an acid fracturing artificial fracture model: based on the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, and the three-dimensional cave development model obtained in step S2, combined with the acid fracturing construction pump injection program parameters, the acid fracturing artificial fracture model is obtained by fitting the simulated injection pressure with the actual injection pressure; S4. Use the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model obtained in step S2, and the acid fracturing artificial fracture model obtained in step S3 to predict production capacity.

2. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: The following steps are also included: S5. Compare the predicted capacity in step S4 with the actual capacity. If the difference between the predicted capacity and the actual capacity is less than a threshold value, there is no need to correct the capacity prediction. If the difference between the predicted capacity and the actual capacity is greater than or equal to the threshold value, correct the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model; use the corrected three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model and the acid-fracturing artificial fracture model to predict the capacity.

3. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 2, characterized in that: The process of revising the capacity forecast is as follows: Redo steps S2-S4, reset the interpolation method when establishing the physical property model, reconstruct the continuous three-dimensional reservoir physical property model, three-dimensional natural fracture model, and three-dimensional cave development model; re-simulate the injection pressure and the actual injection pressure to construct the acid fracturing artificial fracture model.

4. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S1, the reservoir physical property parameters include the reservoir's porosity, permeability, oil and gas saturation, rock Poisson's ratio, rock Young's modulus, vertical stress, horizontal maximum principal stress, horizontal minimum principal stress and pore fluid pressure.

5. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S1, the distribution of natural fractures includes the density, length, height, strike, dip and filling conditions of the natural fractures.

6. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S1, the cave development conditions include the number, size and filling conditions of the caves.

7. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S2, the process of constructing a continuous three-dimensional reservoir property model is as follows: Discrete reservoir physical property parameters are input into the Petrel software to establish a continuous three-dimensional reservoir physical property model.

8. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S2, the process of constructing a continuous three-dimensional natural fracture model is as follows: The distribution of discrete natural fractures is input into the Petrel software, and a continuous three-dimensional natural fracture model is established using the interpolation method.

9. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S2, the process of constructing the continuous three-dimensional cave development model is as follows: The discrete karst cave development conditions were input into the Petrel software, and a continuous three-dimensional karst cave development model was established using the interpolation method.

10. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S3, the specific construction process of the acid fracturing artificial fracture model is as follows: The three-dimensional reservoir property model, three-dimensional natural fracture model, and three-dimensional cave development model obtained in step S2 are imported into the commercial software Gopher, and the acid fracturing pumping program parameters of the well for which production capacity prediction is required are input. The acid fracturing artificial fracture model is obtained by fitting the simulated injection pressure with the actual injection pressure.

11. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S3, the acid fracturing artificial fracture model includes the length, height, width and number of artificial fractures.

12. The method for predicting the production capacity of fracture-cavity carbonate reservoirs by integrated acid fracturing according to claim 1, characterized in that: In step S3, the parameters of the acid fracturing pumping program include injection displacement, injection liquid volume, acid fracturing alternating stages and pre-fluid / acid liquid ratio.

13. An integrated acid fracturing capacity prediction device for fracture-cavity carbonate reservoirs, characterized in that: include: Data acquisition module, used to collect and store reservoir physical parameters, natural fracture distribution and cave development of reservoir; The first data processing module is used to pre-process the reservoir physical property parameters, the distribution of natural fractures, and the development of karst caves, and respectively construct a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional karst cave development model; The second data processing module is used to construct an acid fracturing artificial fracture model by fitting the simulated injection pressure with the actual injection pressure based on the three-dimensional reservoir physical property model, the three-dimensional natural fracture model, the three-dimensional cave development model, and the acid fracturing pump injection program parameters; The capacity prediction module is used to predict the capacity based on the imported three-dimensional reservoir physical property model, three-dimensional natural fracture model, three-dimensional cave development model and acid fracturing artificial fracture model.

14. The integrated acid fracturing production capacity prediction device for fracture-cavity carbonate reservoirs according to claim 13, characterized in that: Also includes: A capacity data acquisition module, electrically connected to the capacity prediction module, for collecting and storing the predicted differential capacity and the actual capacity; A comparison module, electrically connected to the capacity data acquisition module, for calculating the difference between the predicted capacity difference and the actual capacity; The control module determines whether to perform capacity forecast correction by comparing and analyzing the difference calculated by the comparison module and the threshold value; the control module is electrically connected to the comparison module, the first data processing module, the second data processing module and the capacity forecast module. When it is determined that the capacity forecast correction is needed, the control module issues an instruction to redo steps S2-S4, resets the interpolation method when establishing the physical property model, reconstructs a continuous three-dimensional reservoir physical property model, a three-dimensional natural fracture model, and a three-dimensional cave development model; and re-simulates the injection pressure and the actual injection pressure to construct an acid fracturing artificial fracture model.

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