Carbon dioxide fracturing optimization method based on real properties of post-combustion gas and related equipment

Abstract

The present application belongs to the field of carbon dioxide fracturing and computer technology, and provides a carbon dioxide fracturing optimization method based on the real physical properties of the mixed gas after combustion and related equipment, wherein the method comprises the following steps: based on the volume of the fracturing device, the mass of CO2 and the information of the heat releasing material, the components, mass, energy of the mixed gas and the initial energy of the fracturing device are calculated; the final state pressure after connection is obtained through a constant volume test system, and the combustion ratio and the actual released energy of the system are back calculated by combining the volume parameters of the fracturing device and the container, the components, mass and energy of the mixed gas after combustion of the heat releasing material; the working energy of the fracturing device is determined according to the actual released energy; and the regression model is constructed by taking the working energy and the combustion ratio as the target variables and combining the mass of CO2, the mass of the heat releasing material and the thickness of the energy releasing sheet, so as to realize the accurate optimization of the key parameters of the fracturing device. The present application can predict the working energy, reduces the preparation time of the carbon dioxide fracturing device and the consumption of the heat releasing material, and improves the working efficiency.

Description

Technical Field

[0001] This invention relates to the fields of carbon dioxide fracturing and computer technology, and in particular to an optimized method and related equipment for carbon dioxide fracturing based on the real physical properties of post-combustion mixed gases. Background Technology

[0002] Carbon dioxide fracturing technology, with its core characteristics of safety and environmental friendliness, is widely used in clean energy development and geotechnical engineering fields such as coal seam permeability enhancement, rock fracturing, and mineral extraction. This technology utilizes the instantaneous combustion of built-in exothermic materials to release heat, causing the filled liquid CO2 to rapidly undergo a phase transition to a supercritical state. When the system pressure exceeds the fracturing threshold of the fracturing disc, the high-pressure mixed gas is rapidly released, forming a shock wave that achieves controlled rock fracturing. The core of its fracturing effect depends on the energy released by the fracturing device; therefore, accurate calculation of the released energy is crucial for the engineering application of this technology.

[0003] Existing energy calculation models for carbon dioxide fracturing devices have significant flaws. They generally simplify the working fluid to pure CO2, neglecting the initial trapped air within the device, the actual incomplete combustion characteristics of the exothermic materials, and the influence of multi-component gaseous products such as CO2, H2O(g), and N2 generated during combustion. This leads to large discrepancies between the calculated results and actual engineering conditions. Furthermore, current research does not fully consider the true physical properties of multi-component gas mixtures, relying solely on the expansion energy of pure CO2 or empirical methods to assess the released energy. This fails to accurately reflect the thermodynamic processes within the fracturing device and thus cannot provide reliable theoretical support for engineering applications.

[0004] In addition, existing calculation models are mostly developed for fracturing agents of specific specifications, and have not formed a general thermodynamic calculation framework. They have poor scalability, and the model needs to be rebuilt after changing fracturing agents of different sizes, which increases the cost and complexity of engineering applications. Summary of the Invention

[0005] In order to at least solve one of the technical problems existing in the prior art, the present invention provides a carbon dioxide-induced cracking optimization method and related equipment based on the real physical properties of post-combustion mixed gas.

[0006] One aspect of the present invention provides a carbon dioxide fracturing optimization method based on the real physical properties of post-combustion gas mixtures, for use in a carbon dioxide fracturing device, comprising: Based on the blasting energy requirements of the target project, a regression model that considers the actual physical properties of the gas mixture after combustion is used to process the blasting energy requirements, and the optimal parameters of the carbon dioxide fracturing device are obtained. The regression model is obtained through the following steps: Based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and the information of the exothermic material, determine the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide fracturing device. Obtain the final pressure of the constant volume system when connected, and determine the combustion ratio of the exothermic material in the carbon dioxide cracker based on the second volume of the constant volume container, the first volume of the cracker, and the composition, mass, and energy information of the mixed gas after the combustion of the exothermic material. The actual energy released by the carbon dioxide fracturing device is determined based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant volume system. The working capacity of the carbon dioxide fracturing device is determined based on the actual energy released by the device. Based on the working capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center point experimental design with respect to the CO2 mass, the mass of the exothermic material, and the thickness of the energy release plate of the carbon dioxide fracturing device.

[0007] According to the aforementioned carbon dioxide fracturing optimization method based on the real physical properties of post-combustion mixed gases, the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide fracturing device are determined based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and the information of the exothermic material, including: Based on the first volume of the carbon dioxide fracturing device, determine the sum of the internal energies of the initial air and the CO2 injected into the carbon dioxide fracturing device. for:

[0008] in, The total mass of the initial gas mixture is given by the mass of CO2 injected into the carbon dioxide fracturing device. Compared with the original air quality The sum is obtained; The specific internal energy of the initial mixed gas is obtained by calling the thermodynamic parameter database after establishing the components of the first mixed gas. Determine the chemical energy of the exothermic material based on its information. for:

[0009] in, The initial loading mass of the exothermic material, The lower heating value of the exothermic material; Based on total internal energy and the chemical energy of exothermic materials Determine the initial energy of the carbon dioxide fracturing device for: .

[0010] According to the carbon dioxide-induced cracking optimization method based on the actual physical properties of post-combustion mixed gases, the lower heating value of the exothermic material is obtained through the following steps: The higher heating value of the exothermic material was determined by bomb calorimetry, and the lower heating value was obtained by subtracting the latent heat of condensation of water vapor. .

[0011] According to the aforementioned carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases, the method further includes: The initial air mass of the carbon dioxide fracturing device is determined based on the volume of the first volume and the volume of the exothermic material. for:

[0012] in, The initial amount of air matter is calculated using the first volume: , The gas phase volume of the carbon dioxide fracturing device, and the first volume inside the carbon dioxide fracturing device. Subtracting the volume occupied by the solid exothermic material get, This is the molar volume of air; Based on the gas phase volume of the carbon dioxide fracturing device The total mass of the initial mixed gas Determine the density of the gas mixture in the cracker. for:

[0013] Based on the industry-standard specifications for air, the mole fractions of CO2, N2, O2, and Ar in the initial gas mixture are calculated as follows:

[0014]

[0015]

[0016]

[0017] in, This refers to the mole fraction of carbon dioxide. This represents the mole fraction of nitrogen. This represents the mole fraction of oxygen. This represents the mole fraction of argon gas. After establishing the composition of the first mixed gas by the above mole fraction of carbon dioxide, the thermodynamic parameter database can be called to calculate physical properties such as specific internal energy.

[0018] According to the aforementioned carbon dioxide fracturing optimization method based on the real physical properties of the post-combustion mixture, the final pressure of the constant-volume system under connected conditions is obtained, and the combustion ratio of the exothermic material in the carbon dioxide fracturing device is determined based on the second volume of the constant-volume container, the first volume of the fracturing device, and the composition, mass, and energy information of the post-combustion mixture of the exothermic material, including: The initial air mass inside the fixed-volume container is determined based on its second volume. for:

[0019] in, This refers to the initial amount of air in the constant-volume container. , For the second volume; Obtain the mass of the mixed gas in the constant volume system after the carbon dioxide fracturing device and constant volume container are connected and released. for:

[0020] in, Combustion of exothermic materials λ The mass of the gaseous products generated later , It is determined by the properties and composition of the exothermic material; Based on the mass of the first mixed gas in the carbon dioxide fracturing device Mass of gaseous products generated by the combustion of exothermic materials and the initial air mass in the constant volume container Determine the total mass and total mass for:

[0021]

[0022] in, This refers to the total amount of gaseous products generated during combustion. Calculate the density of the gas mixture in a constant volume system. for:

[0023] Based on the properties of exothermic materials, combustion is established. The components of the second mixed gas are then generated. The second mixed gas includes the first mixed gas in the cracker, the original air in the constant volume container, and the gas produced after the combustion of the exothermic material. Establish the second gas mixture component, call the thermodynamic parameter database, and determine the gas mixture density. and final pressure PDetermine the specific internal energy of the gas mixture in a constant volume system. Thus, the final internal energy is obtained. for:

[0024]

[0025] in, Let be the initial internal energy of the air originally contained in the constant-volume container. , The initial specific internal energy of the air inside the constant-volume container is determined by the ambient temperature. To release energy from the exothermic material in the carbon dioxide fracturing device ,and ; Based on the final internal energy and release energy Back-calculation of combustion ratio Its formula is: .

[0026] According to the aforementioned carbon dioxide fracturing optimization method based on the actual physical properties of the post-combustion mixture, the actual energy released by the carbon dioxide fracturing device is equal to the work done by the carbon dioxide fracturing device. To increase functionality The calculation method is as follows: .

[0027] According to the aforementioned optimization method for carbon dioxide fracturing based on the real physical properties of the post-combustion gas mixture, a regression model is constructed based on the work output and combustion ratio of the carbon dioxide fracturing device, along with the CO2 mass, the mass of the exothermic material, and the thickness of the energy dissipation plate of the carbon dioxide fracturing device. This model includes: A two-level full factorial plus center point design was used to obtain multiple sets of experimental data, and the work efficiency was obtained through a computational model. E Analysis of variance was performed, and a Pareto chart of standardized effects was drawn to obtain the order of significant effects and key influencing factors. The relationship between the three parameters and the combustion ratio λ was established, and the functional quantities were calculated. E The regression model.

[0028] Another aspect of the present invention provides a carbon dioxide-induced cracking optimization device based on the real physical properties of post-combustion mixtures, comprising: The first module is used to process the blasting energy demand based on the target project's blasting energy demand using a regression model to obtain the optimal parameters of the carbon dioxide fracturing device. The regression model is obtained through the following modules: The second module is used to determine the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide cracker based on the first volume of the carbon dioxide cracker, the mass of CO2 injected into the carbon dioxide cracker, and the information of the exothermic material. The third module is used to obtain the final pressure of the constant volume system when connected, and to determine the combustion ratio of the exothermic material in the carbon dioxide cracker based on the second volume of the constant volume container, the first volume of the cracker, and information such as the composition, mass, and energy of the mixed gas after the combustion of the exothermic material. The fourth module is used to determine the actual energy released by the carbon dioxide fracturing device based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant volume system. The fifth module is used to determine the working capacity of the carbon dioxide fracturing device based on the actual energy released by the carbon dioxide fracturing device. Based on the working capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center point experimental design with respect to the CO2 mass, the mass of the exothermic material, and the thickness of the energy release plate of the carbon dioxide fracturing device.

[0029] Another aspect of the present invention provides an electronic device, including a processor and a memory; The memory is used to store programs; The processor executes the program to implement the method as described above.

[0030] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the methods described above.

[0031] The beneficial effects of this invention are: it improves computational accuracy and physical realism, overcomes the shortcomings of traditional models that simplify the working fluid to pure CO2, integrates the physical properties of the real mixture of CO2-air-combustion products (based on a thermodynamic parameter database), and introduces combustion ratios. The incomplete combustion characteristics of exothermic materials are quantitatively characterized; the influence of initial trapped air and combustion products on the thermodynamic process is fully considered, making the calculation results more consistent with engineering practice.

[0032] The model is versatile and easy to extend, and it has built a general adiabatic closed thermodynamic calculation framework. The core logic of the model is decoupled from the specifications of the fracturing device. By replacing basic data such as gas phase volume and filling amount, it can be adapted to fracturing devices of different specifications, which greatly reduces the model development cost for different product models.

[0033] The verification methods are scientific and reliable. A constant volume test system was built, and the combustion ratio and actual energy release were deduced by measuring the final pressure, which effectively verified the calculation model and overcame the limitation of traditional models lacking reliable experimental verification.

[0034] It has significant engineering guidance value. Based on a precise physical model, it proposes optimization methods for key parameters such as CO2 mass, exothermic material mass, and energy venting plate thickness. This provides accurate energy calculation basis for fracturing device design and rock crushing and coal seam permeability enhancement operations, and helps to improve fracturing efficiency. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the carbon dioxide-induced cracking optimization process based on the actual physical properties of the post-combustion mixed gas in an embodiment of the present invention.

[0036] Figure 2 This is the initial energy calculation process for the carbon dioxide fracturing device according to an embodiment of the present invention.

[0037] Figure 3 This is the calculation process for the combustion ratio and work output of the carbon dioxide cracker according to an embodiment of the present invention.

[0038] Figure 4 This is a schematic diagram of a carbon dioxide fracturing device according to an embodiment of the present invention.

[0039] Figure 5 This is a schematic diagram of the volume-regulating system according to an embodiment of the present invention.

[0040] Figure 6 This is a schematic diagram of the working process of the carbon dioxide fracturing device according to an embodiment of the present invention, wherein (a) is a schematic diagram of the initial state and combustion process of the carbon dioxide fracturing device; and (b) is a schematic diagram of the final combustion state of the constant volume system.

[0041] Figure 7 This is a diagram of the experimental conditions for a 2-level full factorial plus center point test according to an embodiment of the present invention.

[0042] Figure 8 This is the combustion ratio of an embodiment of the present invention. λ Pareto plot of standardization effect.

[0043] Figure 9 This is the functional quantity of the embodiment of the present invention. E Pareto plot of standardization effect.

[0044] Figure 10 This is the combustion ratio of an embodiment of the present invention. λ Main effect plot.

[0045] Figure 11 This is a functional quantity in an embodiment of the present invention. E Main effect plot.

[0046] Figure 12 This is a schematic diagram of a carbon dioxide-induced cracking optimization device based on the real physical properties of the post-combustion mixed gas according to an embodiment of the present invention.

[0047] Explanation of reference numerals in the attached diagram: 1-Ignition head, 2-Fracturing tube body, 3-Exothermic material, 4-Energy venting plate, 5-Carbon dioxide fracturing device, 6-Volume container, 7-Pressure sensor, 8-Pressure relief valve. Detailed Implementation

[0048] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. Throughout the description, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions. In the following description, suffixes such as "module," "part," or "unit" used to denote elements are used only for the purpose of illustrative purposes and have no specific meaning in themselves. Therefore, "module," "part," or "unit" can be used interchangeably. Terms such as "first," "second," etc., are used only to distinguish technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the sequential relationship of the indicated technical features. In the following description, the consecutive reference numerals for method steps are for ease of review and understanding. Adjusting the implementation order of steps, in conjunction with the overall technical solution of the present invention and the logical relationship between the various steps, will not affect the technical effect achieved by the technical solution of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0049] Combination Figures 1-3 , Figure 1 This is a schematic diagram of the optimized carbon dioxide fracturing process based on the actual physical properties of the post-combustion mixture, according to an embodiment of the present invention. It is used in a volumetric system including a carbon dioxide fracturing device and a volumetric container. The volumetric system references… Figure 4 and Figure 5 The structural diagram of the carbon dioxide cracker and constant volume system shown is referenced in the combustion process diagram. Figure 6 The diagram shows the working process of a carbon dioxide fracturing device, where (a) is a schematic diagram of the initial state and combustion process of the carbon dioxide fracturing device; and (b) is a schematic diagram of the final combustion state of the constant volume system. This is an embodiment of the invention. Figure 1 The process includes, but is not limited to, steps S100~S500: S100, based on the blasting energy requirements of the target project, uses a regression model to process the blasting energy requirements and obtains the optimal parameters of the carbon dioxide fracturing device.

[0050] In some embodiments, the optimal parameters of the carbon dioxide fracturing device can be determined based on actual needs, such as using the smallest fracturing device or materials (e.g., CO2 mass, exothermic material mass, and energy dissipation plate thickness) to meet the blasting energy requirements of the target project, or maximizing the energy output while maintaining a high combustion ratio to reduce the waste of exothermic materials.

[0051] The regression model is obtained through the following steps: S200, based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and the information of the exothermic material, determines the first mixed gas composition, mass, energy, and initial energy of the fracturing device.

[0052] In some embodiments, reference Figure 2 The initial energy calculation process for the carbon dioxide fracturing device shown includes: Based on the first volume of the carbon dioxide fracturing device, determine the sum of the internal energies of the initial air and the CO2 injected into the carbon dioxide fracturing device. for:

[0053] in, The total mass of the initial gas mixture is given by the mass of CO2 injected into the carbon dioxide fracturing device. Compared with the original air quality The sum is obtained; The specific internal energy of the initial mixed gas is obtained by calling the thermodynamic parameter database after establishing the components of the first mixed gas.

[0054] In some embodiments, calling a thermodynamic parameter database involves inputting any two states, such as density and pressure, to obtain other physical properties such as temperature, specific enthalpy, specific internal energy, etc. For example, the thermodynamic parameter database can be a database such as NIST or CoolProp.

[0055] Determine the chemical energy of the exothermic material based on its information. for:

[0056] in, The initial loading mass of the exothermic material, The lower heating value of the exothermic material; Based on total internal energy and the chemical energy of exothermic materials Determine the initial energy of the carbon dioxide fracturing device for:

[0057] Furthermore, the original air mass of the carbon dioxide fracturing device is determined based on the first volume and the volume of the exothermic material. for:

[0058] in, The initial amount of air matter is calculated using the first volume: , The gas phase volume of the carbon dioxide fracturing device, and the first volume inside the carbon dioxide fracturing device. Subtracting the volume occupied by the solid exothermic material get, This is the molar volume of air; Based on the gas phase volume of the carbon dioxide fracturing device The total mass of the initial mixed gas Determine the density of the gas mixture in the cracker. for:

[0059] Based on the industry-standard specifications for air, the mole fractions of CO2, N2, O2, and Ar in the initial gas mixture are calculated as follows:

[0060]

[0061]

[0062]

[0063] in, This refers to the mole fraction of carbon dioxide. This represents the mole fraction of nitrogen. This represents the mole fraction of oxygen. This represents the mole fraction of argon gas. Molar amount of carbon dioxide After establishing the composition of the first mixed gas using the above mole fractions, the thermodynamic parameter database can be called to calculate physical properties such as specific internal energy.

[0064] For example, a 38mm carbon dioxide fracturing device is selected, whose total internal volume is... When 0.06 kg of exothermic material is loaded, the solid-phase exothermic material occupies a volume of... Therefore, the gas phase volume of the fracturing device ; Under standard conditions, the molar volume of air is 24.05 L / mol, the molar mass of air is 28.97 g / mol, and the molar mass of CO2 is 44.01 g / mol. The exothermic material is a composite mixture of salicylic acid, potassium perchlorate, and ammonium oxalate, with the equivalent molecular formula C. 1.386 H 1.78 2N 0.189 O 3.671 Cl 0.695 K 0.695 Its higher heating value was determined to be 4500 kJ / kg by the bomb calorimeter method. After deducting the latent heat of condensation of water vapor, the lower heating value was... The total mass of gaseous products generated by the complete combustion of the exothermic material is 0.606 kg / kg (each kg of exothermic material produces 0.606 kg of gaseous products upon combustion). , n =0.606, and the mass percentages of each component are: CO2-76.4%, H2O(g)-20.1%, N2-3.3%, O2-0.2%.

[0065] For example, 0.36 kg of CO2 is injected into a 38 mm fracturing device, and the gas phase volume of the air trapped inside the device is... The calculated mass of stagnant air is 4.89 × 10⁻⁶. -4 kg, therefore the total initial mass of the mixed gas ; Initial gas mixture density Calculate the mole fractions of each component: CO₂ -0.99794, N₂ -0.00161, O₂ -0.00043, Ar -0.00002; Substitute the mole fractions, densities, and initial temperature of 298.15 K into the thermodynamic parameter database to obtain the specific internal energy of the initial gas mixture. Therefore, the total internal energy of the initial mixed gas ; Exothermic material chemical energy ; Initial energy of the fracturing device .

[0066] In some embodiments, the upper heating value of the exothermic material is determined by bomb calorimetry, and the lower heating value is obtained after subtracting the latent heat of condensation of water vapor. The equivalent molecular formula of the exothermic material in the examples is C 1.386 H 1.782 N 0.189 O 3.671 Cl 0.69 5K 0.695 For example, its higher heating value was measured to be 4500 kJ / kg using the bomb calorimetry method. After deducting the latent heat of condensation of water vapor, the lower heating value was... .

[0067] S300: Obtain the final pressure of the constant volume system when connected, and determine the combustion ratio of the exothermic material in the carbon dioxide cracker based on the second volume of the constant volume container, the first volume of the cracker, and information such as the composition, mass, and energy of the mixed gas after the combustion of the exothermic material.

[0068] In some embodiments, the original air mass inside the constant volume container is determined based on the second volume of the constant volume container. for:

[0069] in, This refers to the initial amount of air in the constant-volume container. , For the second volume; Obtain the mass of the mixed gas in the constant volume system after the carbon dioxide fracturing device and constant volume container are connected and released. for:

[0070] in, Combustion of exothermic materials λ The mass of the gaseous products generated later , n It is determined by the properties and composition of the exothermic material; Based on the mass of the first mixed gas in the carbon dioxide fracturing device Mass of gaseous products generated by the combustion of exothermic materials and the initial air mass in the constant volume container Determine the total mass and total mass for:

[0071]

[0072] in, This refers to the total amount of gaseous products generated during combustion. Calculate the density of the gas mixture in a constant volume system. for:

[0073] Based on the properties of exothermic materials, combustion is established. The components of the second mixed gas are then generated. The second mixed gas includes the first mixed gas in the cracker, the original air in the constant volume container, and the gas produced after the combustion of the exothermic material.

[0074] After establishing the second gas mixture components, the thermodynamic parameter database can be accessed, based on the density of the gas mixture. and final pressure PDetermine the specific internal energy of the gas mixture in a constant volume system. Thus, the final internal energy is obtained. for:

[0075]

[0076] in, Let be the initial internal energy of the air originally contained in the constant-volume container. , The initial specific internal energy of the air inside the constant-volume container is determined by the ambient temperature. To release energy from the exothermic material in the carbon dioxide fracturing device ,and ; Based on the final internal energy and release energy And reverse calculate the combustion ratio Its formula is:

[0077] For example, the calculations for combustion ratio, post-combustion gas mixture properties, and energy are shown below: The 38mm fracturing device is sealed and connected to the constant volume container to form an adiabatic closed thermodynamic system. After the fracturing device is ignited, the exothermic material is released and combusted to generate CO2, H2O(g), N2, and O2 gaseous products. These products are mixed with the initial CO2-air mixture and the initial air in the pressure tank to form a final multi-component mixed gas. Gases produced after combustion:

[0078] The constant volume container is a custom-made sealed pressure vessel with a specific internal volume. ; Air mass inside the constant volume container:

[0079] Density of the mixed gas in the constant volume system:

[0080] The gases produced by combustion include:

[0081]

[0082]

[0083]

[0084]

[0085] The mixed gases in the constant volume system include: , , , .

[0086] Mole fraction of carbon dioxide:

[0087] Mole fraction of nitrogen:

[0088] Mole fraction of oxygen:

[0089] Mole fraction of water vapor:

[0090] Mole fraction of argon:

[0091] A constant-volume system has energy conservation:

[0092] Measured pressure of constant volume system P =1.68MPa, the calculation model of the above equations only λ An unknown variable is obtained through iteration. λ =0.64.

[0093] Therefore, E = 243.61 kJ. , , , , , , .

[0094] S400 determines the actual released energy of the carbon dioxide fracturing device based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant volume system.

[0095] In some embodiments, the carbon dioxide fracturing device releases energy. The calculation method is as follows:

[0096] For example, E = 243.61 kJ.

[0097] S500: The working capacity of the carbon dioxide fracturing device is determined based on the actual energy released by the carbon dioxide fracturing device. Based on the working capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center point experimental design with respect to the mass of CO2, the mass of the exothermic material, and the thickness of the energy release plate of the carbon dioxide fracturing device.

[0098] In some embodiments, a two-level full factorial plus center point design is used to obtain multiple sets of experimental data, and the work-energy quantity is obtained through a computational model. E Analysis of variance was performed, and a Pareto chart of standardized effects was drawn to obtain the order of significant effects and key influencing factors. A relationship between the three parameters and the combustion ratio was established. λ , make functional quantity E The regression model.

[0099] The functional capacity of the fracturing device is determined by three key parameters: CO2 mass (factor A), exothermic material mass (factor B), and energy dissipation plate thickness (factor C). To systematically analyze their influence, a two-level full factorial plus center-point experimental design was adopted, with the experimental conditions as follows: Figure 7 As shown, the factor levels are set as follows: CO2 mass (A): 0.2 kg (low level, -1), 0.36 kg (high level, +1) Exothermic material mass (B): 0.05 kg (low level, -1), 0.07 kg (high level, +1) Energy drain plate thickness (C): 1.0mm (low level, -1), 1.6mm (high level, +1) The calculation results are shown in Table 1.

[0100] Table 1. Results of the 2-level full factorial plus center point experiment and calculations.

[0101] (1) Plot the Pareto chart of the normalized effect of combustion ratio λ, such as λ = λ. Figure 9 As shown, the order of significant influence is: AA > C > A > CC > B > BC > ABC > AB > BB > AC. The main influencing factors are: the interaction of AA, C, A, CC, B, and BC. Based on this, a regression model containing the above terms is established:

[0102] The model has strong explanatory power: residual standard deviation (RSD) = 0.023, R² = 91.99%, corrected R² = 87.18%, and predicted R² = 74.52%. The lack-of-fit term is not significant (P = 0.254), indicating that the model fits well and has moderate predictive power for λ.

[0103] (2) Calculate the work quantity E and draw a Pareto chart of the standardized effects of the work quantity E, such as... Figure 9 As shown, the order of significant effects is: B > A > AA > C > CC > ABC > BC > AB > AC > BB. The key factors are: B, A, AA, C, and CC. Based on this, a regression model containing the above terms is established:

[0104] According to embodiments of the present invention, the model performs excellently, with a residual standard deviation of 5.85, R² of 97.38%, corrected R² of 96.19%, and predicted R² of 93.11%. The lack-of-fit term is not significant (P = 0.246), indicating that the model fits extremely well, accurately captures influencing factors, and reliably predicts E.

[0105] The regression models for both the combustion ratio λ and the amount of work done E showed significant quadratic effects. By fixing the two factors at the central level (0) and the single factor within the coding interval (-1 to +1), the fitted response was calculated, and the main effect plot was obtained, as shown in the figure. Figure 10 , Figure 11 As shown: The combustion ratio λ has a significant inverted U-shaped relationship with the CO2 mass (A), indicating the existence of an optimal CO2 loading amount; the exothermic material mass (B) has a weak linear negative effect on the combustion ratio λ; the energy dissipation plate thickness (C) has a relatively weak U-shaped influence on the combustion ratio, with a curvature smaller than that of factor A.

[0106] The energy output E and the CO2 mass (A) have an inverted U-shaped relationship, indicating an optimal CO2 loading amount; the exothermic material mass (B) has a very strong linear positive effect on the energy output E; the energy dissipation plate thickness (C) has a weak U-shaped effect on the energy output E, with a curvature smaller than that of factor A.

[0107] The model shows that the optimal combinations of λ are: A=0.1313, B=-1, C=1; and the optimal combinations of E are: A=0.2929, B=1, C=1. From an engineering perspective, the goal is to maximize the amount of work done while maintaining a high combustion ratio to reduce waste of exothermic materials. Therefore, the recommended optimization strategy is: within the pressure limits of the device, increase the quality of the exothermic material and the thickness of the energy dissipation plates, while controlling the CO2 loading at a moderately high level.

[0108] The optimal parameters predicted by the regression model are: CO2 mass 0.28kg + exothermic material mass 0.07kg + rupture disc thickness 1.6mm, combustion ratio λ=0.808, and energy done E=309.82kJ.

[0109] Under these conditions, the measured pressure of the constant-volume system was 2.28 MPa. Based on the model calculations, the corresponding values ​​were E = 298.16 kJ and λ = 0.761. The predicted and measured values ​​showed good agreement, confirming the model's accuracy and reliability, and its applicability for performance optimization in practical engineering projects.

[0110] The method of this invention is not only applicable to 38mm CO2 fracturing devices, but can also be directly extended to CO2 fracturing devices of different specifications such as 50mm and 76mm. Only by replacing the basic data such as fracturing device volume, CO2 filling amount, and exothermic material loading amount, the energy released by fracturing devices of different specifications can be accurately calculated and the parameters optimized, which has broad engineering application prospects.

[0111] Figure 12 This is a schematic diagram of a carbon dioxide-induced cracking optimization device based on the actual physical properties of the post-combustion mixture, according to an embodiment of the present invention. The device includes a first module 1210, a second module 1220, a third module 1230, a fourth module 1240, and a fifth module 1250.

[0112] The system comprises five modules: The first module processes the blasting energy requirement of the target project using a regression model to obtain the optimal parameters of the carbon dioxide fracturing device (CO2 fracturing device). The regression model is derived through the following modules: The second module determines the first mixed gas composition, mass, energy, and initial energy of the CO2 fracturing device based on its first volume, the mass of CO2 injected into the device, and information on the exothermic material. The third module obtains the final pressure of the constant-volume system during connection and determines the combustion ratio of the exothermic material in the CO2 fracturing device based on the second volume of the constant-volume container, the first volume of the fracturing device, and the mixed gas composition, mass, and energy after the exothermic material combustion. The fourth module determines the actual released energy of the CO2 fracturing device based on its initial energy, the combustion ratio of the exothermic material, and the final pressure of the constant-volume system. The fifth module determines the work output of the CO2 fracturing device based on its actual released energy and, based on the work output and combustion ratio, constructs a regression model with respect to the mass of CO2, the mass of the exothermic material, and the thickness of the energy release plate of the CO2 fracturing device using a two-level full factorial plus center-point experimental design.

[0113] For example, with the cooperation of the first, second, third, fourth, and fifth modules in the device, the embodiment device can implement any of the aforementioned carbon dioxide fracturing optimization methods based on the real physical properties of the post-combustion mixture gas. Specifically, it obtains the optimal parameters of the carbon dioxide fracturing device by processing the blasting energy requirement according to the target project using a regression model. The regression model is obtained through the following steps: determining the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide fracturing device based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and the information of the exothermic material; obtaining the constant volume system during connection. The final pressure of the system is used to determine the combustion ratio of the exothermic material in the carbon dioxide fracturing device based on the second volume of the constant-volume container, the first volume of the fracturing device, and information such as the composition, mass, and energy of the gas mixture after the combustion of the exothermic material. The actual energy released by the carbon dioxide fracturing device is determined based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant-volume system. The work capacity of the carbon dioxide fracturing device is determined based on the actual energy released. Based on the work capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center-point experimental design, relating it to the mass of CO2, the mass of the exothermic material, and the thickness of the energy-dissipating plate of the carbon dioxide fracturing device. The beneficial effects of this invention are: improved computational accuracy and physical realism; elimination of the shortcomings of traditional models that simplify the working fluid to pure CO2; integration of the actual physical properties of the CO2-air-combustion product mixture (based on a thermodynamic parameter database); and introduction of the combustion ratio. λ This study quantitatively characterizes the incomplete combustion characteristics of exothermic materials. It fully considers the influence of initial trapped air and combustion products on the thermodynamic process, making the calculation results more consistent with engineering realities. The model is versatile and easily expandable, constructing a general adiabatic closed thermodynamic calculation framework, with the core logic of the model decoupled from the fracturing device specifications. By replacing basic data such as gas phase volume and filling amount, it can be adapted to fracturing devices of different specifications, significantly reducing the model development cost for different product models. The verification methods are scientific and reliable. A constant-volume testing system was built, and the combustion ratio and actual energy release were deduced from the measured final pressure, achieving effective verification of the calculation model and overcoming the limitation of traditional models lacking reliable experimental verification. It has significant engineering guidance value. Based on a precise physical model, optimization methods for key parameters such as CO2 mass, exothermic material mass, and energy dissipation plate thickness are proposed, providing accurate energy calculation basis for fracturing device design and rock fracturing and coal seam permeability enhancement operations, contributing to improved fracturing efficiency.

[0114] This invention also provides an electronic device, which includes a processor and a memory; The memory stores the program; The processor executes a program to perform the aforementioned carbon dioxide fracturing optimization method based on the real properties of post-combustion mixtures; the electronic device has the function of carrying and running the software system for carbon dioxide fracturing optimization based on the real properties of post-combustion mixtures provided in the embodiments of the present invention, such as a personal computer, minicomputer, mainframe, workstation, network or distributed computing environment, standalone or integrated computer platform, or communicating with charged particle tools or other imaging devices, etc.

[0115] This invention also provides a computer-readable storage medium storing a program that is executed by a processor to implement the carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases as described above.

[0116] In some alternative embodiments, the functions / operations mentioned in the block diagrams may not occur in the order shown in the operation diagrams. For example, depending on the functions / operations involved, two consecutively shown blocks may actually be executed substantially simultaneously, or the blocks may sometimes be executed in reverse order. Furthermore, the embodiments presented and described in the flowcharts of this invention are provided by way of example to provide a more comprehensive understanding of the technology. The disclosed methods are not limited to the operations and logic flows presented in the embodiments of this invention. Alternative embodiments are contemplated, in which the order of various operations is changed and sub-operations described as part of a larger operation are executed independently.

[0117] This invention also discloses a computer program product or computer program, which includes computer instructions stored in a computer-readable storage medium. A processor of a computer device can read the computer instructions from the computer-readable storage medium and execute the computer instructions, causing the computer device to perform the aforementioned carbon dioxide-induced cracking optimization method based on the actual physical properties of the post-combustion mixture.

[0118] Furthermore, although the invention has been described in the context of functional modules, it should be understood that, unless otherwise stated, one or more of the described functions and / or features may be integrated into a single physical device and / or software module, or one or more functions and / or features may be implemented in a separate physical device or software module. It is also understood that a detailed discussion of the actual implementation of each module is unnecessary for understanding the invention. Rather, considering the properties, functions, and internal relationships of the various functional modules in the apparatus disclosed in the embodiments of the invention, the actual implementation of the module will be understood within the scope of conventional skill of an engineer. Therefore, those skilled in the art can implement the invention as set forth in the claims using ordinary techniques without excessive experimentation. It is also understood that the specific concepts disclosed are merely illustrative and are not intended to limit the scope of the invention, which is determined by the full scope of the appended claims and their equivalents.

[0119] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, essentially, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0120] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can include, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device.

[0121] More specific examples of computer-readable media (a non-exhaustive list) include: electrical connections (electronic devices) having one or more wires, portable computer disk drives (magnetic devices), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Furthermore, computer-readable media can even be paper or other suitable media on which the program can be printed, because the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in computer memory.

[0122] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0123] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0124] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

[0125] The above is a detailed description of the preferred embodiments of the present invention, but the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalent modifications or substitutions are all included within the scope defined by the claims of this application.

Claims

1. A carbon dioxide fracturing optimization method based on the real physical properties of post-combustion gas mixtures, used in a carbon dioxide fracturing device, characterized in that, include: Based on the blasting energy requirements of the target project, a regression model that considers the actual physical properties of the gas mixture after combustion is used to process the blasting energy requirements, and the optimal parameters of the carbon dioxide fracturing device are obtained. The regression model is obtained through the following steps: Based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and the information of the exothermic material, determine the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide fracturing device. Obtain the final pressure of the constant volume system when connected, and determine the combustion ratio of the exothermic material in the carbon dioxide cracker based on the second volume of the constant volume container, the first volume of the cracker, and the composition, mass, and energy information of the mixed gas after the combustion of the exothermic material. The actual energy released by the carbon dioxide fracturing device is determined based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant volume system. The working capacity of the carbon dioxide fracturing device is determined based on the actual energy released by the device. Based on the working capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center point experimental design with respect to the CO2 mass, the mass of the exothermic material, and the thickness of the energy release plate of the carbon dioxide fracturing device.

2. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gas as described in claim 1, characterized in that, The determination of the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide fracturing device based on the first volume of the carbon dioxide fracturing device, the mass of CO2 injected into the carbon dioxide fracturing device, and information on the exothermic material includes: Based on the first volume of the carbon dioxide fracturing device, determine the sum of the internal energies of the initial air and the CO2 injected into the carbon dioxide fracturing device. for: in, The total mass of the initial gas mixture is given by the mass of CO2 injected into the carbon dioxide fracturing device. Compared with the original air quality The sum is obtained; The specific internal energy of the initial mixed gas is obtained by calling the thermodynamic parameter database after establishing the components of the first mixed gas. Determine the chemical energy of the exothermic material based on its information. for: in, The initial loading mass of the exothermic material, The lower heating value of the exothermic material; Based on total internal energy and the chemical energy of exothermic materials Determine the initial energy of the carbon dioxide fracturing device for: .

3. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gas as described in claim 2, characterized in that, The lower heating value of the exothermic material is obtained through the following steps: The higher heating value of the exothermic material was determined by bomb calorimetry, and the lower heating value was obtained by subtracting the latent heat of condensation of water vapor. .

4. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gas as described in claim 2, characterized in that, The method further includes: The initial air mass of the carbon dioxide fracturing device is determined based on the volume of the first volume and the volume of the exothermic material. for: in, The initial amount of air matter is calculated using the first volume: , The gas phase volume of the carbon dioxide fracturing device, and the first volume inside the carbon dioxide fracturing device. Subtracting the volume occupied by the solid exothermic material get, This represents the molar volume of air. Based on the gas phase volume of the carbon dioxide fracturing device The total mass of the initial mixed gas Determine the density of the gas mixture in the cracker. for: Based on the industry-standard specifications for air, the mole fractions of CO2, N2, O2, and Ar in the initial gas mixture are calculated as follows: in, This refers to the mole fraction of carbon dioxide. This represents the mole fraction of nitrogen. This represents the mole fraction of oxygen. This represents the mole fraction of argon gas. After establishing the composition of the first mixed gas by the above mole fraction of carbon dioxide, the thermodynamic parameter database can be called to calculate physical properties such as specific internal energy.

5. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases according to claim 1, characterized in that, The process of obtaining the final pressure of the constant-volume system during connection, and determining the combustion ratio of the exothermic material in the carbon dioxide fracturing device based on the second volume of the constant-volume container, the first volume of the fracturing device, and the composition, mass, and energy information of the mixed gas after the combustion of the exothermic material, includes: The initial air mass inside the fixed-volume container is determined based on its second volume. for: in, This represents the initial amount of air in the constant-volume container. , For the second volume; Obtain the mass of the mixed gas in the constant volume system after the carbon dioxide fracturing device and constant volume container are connected and released. for: in, Combustion of exothermic materials λ The mass of the gaseous products generated later , It is determined by the properties and composition of the exothermic material; Based on the mass of the first mixed gas in the carbon dioxide fracturing device Mass of gaseous products generated by the combustion of exothermic materials and the initial air mass in the constant volume container Determine the total mass and total mass for: in, This refers to the total amount of gaseous products generated during combustion. Calculate the density of the gas mixture in a constant volume system. for: Based on the properties of exothermic materials, combustion is established. The components of the second mixed gas are then generated. The second mixed gas includes the first mixed gas in the cracker, the original air in the constant volume container, and the gas produced after the combustion of the exothermic material. Establish the second gas mixture component, call the thermodynamic parameter database, and determine the gas mixture density. and final pressure P Determine the specific internal energy of the gas mixture in a constant volume system. Thus, the final internal energy is obtained. for: in, Let be the initial internal energy of the air inside the constant-volume container. , The initial specific internal energy of the air inside the constant-volume container is determined by the ambient temperature. To release energy from the exothermic material in the carbon dioxide fracturing device ,and ; Based on the final internal energy and release energy Back-calculation of combustion ratio Its formula is: .

6. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases according to claim 1, characterized in that, The actual energy released by the carbon dioxide fracturing device is equal to the work done by the carbon dioxide fracturing device. To make functional quantity The calculation method is as follows: .

7. The carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases according to claim 6, characterized in that, The regression model, constructed based on the working power and combustion ratio of the carbon dioxide fracturing device and its correlation with CO2 mass, exothermic material mass, and the thickness of the energy dissipation plate of the carbon dioxide fracturing device, includes: A two-level full factorial plus center point design was used to obtain multiple sets of experimental data, and the work efficiency was obtained through a computational model. E Analysis of variance was performed, and a Pareto chart of standardized effects was drawn to obtain the order of significant effects and key influencing factors. The relationship between the three parameters and the combustion ratio λ was established, and the functional quantities were calculated. E The regression model.

8. A carbon dioxide-induced fracturing optimization device based on the actual physical properties of post-combustion gas mixtures, characterized in that, include: The first module is used to process the blasting energy demand based on the target project's blasting energy demand using a regression model to obtain the optimal parameters of the carbon dioxide fracturing device. The regression model is obtained through the following modules: The second module is used to determine the first mixed gas composition, mass, energy, and initial energy of the carbon dioxide cracker based on the first volume of the carbon dioxide cracker, the mass of CO2 injected into the carbon dioxide cracker, and the information of the exothermic material. The third module is used to obtain the final pressure of the constant volume system when connected, and to determine the combustion ratio of the exothermic material in the carbon dioxide cracker based on the second volume of the constant volume container, the first volume of the cracker, and information such as the composition, mass, and energy of the mixed gas after the combustion of the exothermic material. The fourth module is used to determine the actual energy released by the carbon dioxide fracturing device based on the initial energy of the carbon dioxide fracturing device, the combustion ratio of the exothermic material, and the final pressure of the constant volume system. The fifth module is used to determine the working capacity of the carbon dioxide fracturing device based on the actual energy released by the carbon dioxide fracturing device. Based on the working capacity and combustion ratio of the carbon dioxide fracturing device, a regression model is constructed using a two-level full factorial plus center point experimental design with respect to the CO2 mass, the mass of the exothermic material, and the thickness of the energy release plate of the carbon dioxide fracturing device.

9. An electronic device, characterized in that, Including the processor and memory; The memory is used to store programs; The processor executes the program to implement the carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gas as described in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The storage medium stores a program that is executed by a processor to implement the carbon dioxide-induced cracking optimization method based on the real physical properties of post-combustion mixed gases as described in any one of claims 1-7.

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