Method, system, storage medium and terminal for predicting high-pressure natural gas compression factor

Abstract

This invention provides a method, system, storage medium, and terminal for predicting the compressibility factor of high-pressure natural gas, comprising the following steps: acquiring the composition information, actual pressure, and actual temperature of high-pressure natural gas; calculating the critical pressure and critical temperature of the high-pressure natural gas based on the composition information; calculating the relative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure; calculating the relative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature; and applying the high-pressure natural gas compressibility factor regression formula Z = P r (A·T r +B)+C·T r +D calculates the compressibility factor of the high-pressure natural gas, where Z represents the compressibility factor, and P r T represents the comparative pressure. r The comparison temperature is represented by A, B, C, and D, which are variable coefficients that vary with the comparison pressure. The method, system, storage medium, and terminal for predicting the high-pressure natural gas compressibility factor of this invention solve the problems of inconvenient calculation, unclear applicable conditions, and large deviations in the existing GaPal formula for high-pressure natural gas compressibility factor.

Description

Technical Field

[0001] This invention relates to the technical fields of natural gas development, pipeline transportation and metering, and in particular to a method, system, storage medium and terminal for predicting the compressibility factor of high-pressure natural gas. Background Technology

[0002] The compressibility factor represents the degree of deviation between the actual gas and the ideal gas. It is one of the important fundamental physical property parameters in the design and research of gas reservoir engineering, gas production engineering, and surface engineering, and has a significant impact on the accuracy of calculations such as mass balance, gas reservoir reserves, processing technology, and pipeline metering. Currently, experimental testing is the most direct and reliable way to obtain the compressibility factor of natural gas. However, due to the limitations of experimental testing conditions, the following three methods are generally used in practice to calculate the compressibility factor:

[0003] (1) The drawing method, the most commonly used is the Standing-Katz drawing, which has the advantages of being fast and convenient, but has the disadvantage of having large errors, and is rarely used in engineering design;

[0004] (2) Software calculation method based on state equations. Commonly used state equations include BWRS, SRK, PR, LKP, etc. The calculation accuracy and applicable scope of each state equation are not the same. They need to be compared and evaluated. Furthermore, improper selection of state equations can lead to large errors.

[0005] (3) Empirical formula method, commonly used ones include HTP, HY, DPR, DAK, CRANMER, PAPAY, Zhang Guodong method, Li Xiangfang improved method, etc. These empirical formulas usually require iterative calculation and have high accuracy only within a certain pressure and temperature range.

[0006] Considering the simplicity and convenience of using empirical formulas, GaPal proposed a formula for predicting the compressibility factor of natural gas: Z = P r (A·T r +B)+C·T r +D. Where Z represents the natural gas compressibility factor, which is dimensionless; P r T represents the relative pressure of natural gas, dimensionless; r The relative temperature of natural gas is dimensionless; A, B, C, and D represent variable coefficients, which are also dimensionless.

[0007] The above formula is a general formula derived from fitting the Standin compressibility factor diagram. Within the range of 0.2–5.4 relative pressures, it is divided into 12 ranges based on different relative pressures and temperatures, each corresponding to a different set of coefficients. For natural gas with relative pressures in the range of 5.4–15.0, GaPal provides the formula Z = P for predicting the compressibility factor. r (3.66T r+0.711) -1.4667 -1.637 / (0.319T r +0.522)+2.071; Natural gas with a relative pressure greater than 5.4 generally exceeds 20 MPa. According to the pressure pipeline classification system, "Nominal pressure of high-pressure pipeline is 10-100 MPa", natural gas with a relative pressure in the range of 5.4 to 15.0 is classified as high-pressure natural gas.

[0008] Since its introduction, the GaPal natural gas compressibility factor prediction formula has been widely used due to its convenience and practicality. However, the calculation of the compressibility factor prediction formula for high-pressure natural gas is not simple, and it does not have the same detailed application range as for medium and low-pressure natural gas, resulting in certain limitations of the formula.

[0009] Therefore, simplifying the prediction and calculation process of high-pressure natural gas compressibility factor and refining the applicable scope of the formula to reduce deviations have become current hot issues. Summary of the Invention

[0010] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a method, system, storage medium and terminal for predicting the compressibility factor of high-pressure natural gas, which solves the problems of inconvenience in calculating the compressibility factor of high-pressure natural gas, unclear applicable conditions and large deviations in the existing GaPal formula.

[0011] To achieve the above and other related objectives, this invention provides a method for predicting the compressibility factor of high-pressure natural gas, comprising the following steps: obtaining the composition information, actual pressure, and actual temperature of high-pressure natural gas; calculating the critical pressure and critical temperature of the high-pressure natural gas based on the composition information; calculating the relative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure; calculating the relative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature; and applying the high-pressure natural gas compressibility factor regression formula Z = P r (A·T r +B)+C·T r +D calculates the compressibility factor of the high-pressure natural gas, where Z represents the compressibility factor, and P r T represents the comparative pressure. r The reference temperature is represented by A, B, C, and D, which are variable coefficients that vary with the reference pressure.

[0012] In one embodiment of the present invention, the component information includes the number of components in high-pressure natural gas, the mole fraction of a single component in the natural gas, and the critical pressure and critical temperature of the single component.

[0013] Calculating the critical pressure and critical temperature of the high-pressure natural gas based on the component information includes the following steps:

[0014] according to Calculate the critical pressure; where y i P represents the mole fraction of a single component in the natural gas, n represents the number of components in the high-pressure natural gas, and P represents the number of components in the natural gas. c P represents the critical pressure. ci This represents the critical pressure of component i;

[0015] according to Calculate the critical temperature, where T c T represents the critical temperature. ci This represents the critical temperature of component i.

[0016] In one embodiment of the present invention, according to P r =P / P c Calculate the comparative pressure, based on T r =T / T c Calculate the contrast temperature

[0017] Degree, where P r P represents the comparative pressure, and P represents the actual pressure. c T represents the critical pressure. r T represents the comparison temperature, and T represents the actual temperature. c This indicates the critical temperature.

[0018] In one embodiment of the present invention, when 5.4 < P r When ≤7.7, A=0.04842, B=-0.03494, C=-0.12493, D=0.86134, where P r This indicates the comparative pressure.

[0019] In one embodiment of the present invention, when 7.7 < P r When ≤10.0, A=-0.07087, B=0.16140, C=0.75344, D=-0.58920, where P r This indicates the comparative pressure.

[0020] In one embodiment of the present invention, when 10.0 < P r When ≤12.1, A=-0.06447, B=0.16244, C=0.70931, D=-0.63938, where P r This indicates the comparative pressure.

[0021] In one embodiment of the present invention, when 12.1 < P r When ≤15.0, A=-0.07715, B=0.20533, C=0.86557, D=-1.16558, where P rThis indicates the comparative pressure.

[0022] This invention provides a system for predicting the compressibility factor of high-pressure natural gas, comprising an acquisition module, a first calculation module, a second calculation module, and a prediction module;

[0023] The acquisition module is used to acquire the composition information, actual pressure, and actual temperature of high-pressure natural gas;

[0024] The first calculation module is used to calculate the critical pressure and critical temperature of the high-pressure natural gas based on the component information;

[0025] The second calculation module is used to calculate the comparative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure, and to calculate the comparative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature.

[0026] The prediction module is used to predict based on the high-pressure natural gas compressibility factor regression formula Z=P. r (A·T r +B)+C·T r +D calculates the compressibility factor of the high-pressure natural gas, where Z represents the compressibility factor, and P r T represents the comparative pressure. r The reference temperature is represented by A, B, C, and D, which are variable coefficients that vary with the reference pressure.

[0027] The present invention provides a storage medium storing a computer program that, when executed by a processor, implements the above-described method for predicting the compressibility factor of high-pressure natural gas.

[0028] This invention provides a terminal for predicting the compressibility factor of high-pressure natural gas, comprising: a processor and a memory;

[0029] The memory is used to store computer programs;

[0030] The processor is used to execute the computer program stored in the memory, so that the high-pressure natural gas compressibility factor prediction terminal performs the above-described high-pressure natural gas compressibility factor prediction method.

[0031] As described above, the method, system, storage medium, and terminal for predicting the compressibility factor of high-pressure natural gas of the present invention have the following beneficial effects:

[0032] (1) The high-pressure natural gas compressibility factor regression formula adopted uses a variable coefficient, which changes according to the change of the natural gas comparative pressure, effectively expanding the scope of application;

[0033] (2) Compared with the existing GaPal formula, the calculation process is simpler and the prediction results are closer to the actual compressibility factor of high-pressure natural gas. It can better fit and predict the change law of high-pressure natural gas compressibility factor with pressure and temperature, and solve the problems of inconvenient calculation, unclear applicable conditions and large deviation of high-pressure natural gas compressibility factor of existing GaPal formula. Attached Figure Description

[0034] Figure 1 The flowchart shown is an embodiment of the method for predicting the compressibility factor of high-pressure natural gas according to the present invention;

[0035] Figure 2 The diagram shown is a structural schematic of the high-pressure natural gas compressibility factor prediction system of the present invention in one embodiment;

[0036] Figure 3 The diagram shown is a structural schematic of a high-pressure natural gas compressibility factor prediction terminal according to an embodiment of the present invention.

[0037] Component designation explanation

[0038] 21 Acquisition Module

[0039] 22 First Calculation Module

[0040] 23 Second Calculation Module

[0041] 24 Prediction Module

[0042] 31 processors

[0043] 32 Memory Detailed Implementation

[0044] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0045] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0046] The method, system, storage medium, and terminal for predicting the high-pressure natural gas compressibility factor of the present invention predict the high-pressure natural gas compressibility factor by using a high-pressure natural gas compressibility factor regression formula containing variable coefficients. This solves the problems of inconvenient calculation, unclear applicable conditions, and large deviations of the existing GaPal formula for high-pressure natural gas compressibility factor, and is highly practical.

[0047] like Figure 1 As shown, in one embodiment, the method for predicting the compressibility factor of high-pressure natural gas according to the present invention includes the following steps:

[0048] Step S1: Obtain the composition information, actual pressure, and actual temperature of the high-pressure natural gas.

[0049] Specifically, the high-pressure natural gas contains multiple components, and information about each component needs to be obtained. In one embodiment of the present invention, the component information includes the quantity of each component in the high-pressure natural gas, the mole fraction of each component in the natural gas, and the critical pressure and critical temperature of each component.

[0050] Step S2: Calculate the critical pressure and critical temperature of the high-pressure natural gas based on the component information.

[0051] Specifically, calculating the critical pressure and critical temperature of the high-pressure natural gas based on the component information includes the following steps:

[0052] 21) According to Calculate the critical pressure; where y i P represents the mole fraction of a single component in the natural gas, n represents the number of components in the high-pressure natural gas, and P represents the number of components in the natural gas. c P represents the critical pressure. ci This represents the critical pressure of component i.

[0053] 22) According to Calculate the critical temperature, where T c T represents the critical temperature. ci This represents the critical temperature of component i.

[0054] Step S3: Calculate the comparative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure, and calculate the comparative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature.

[0055] Specifically, according to P r =P / P c Calculate the comparative pressure, based on T r =T / T c Calculate the comparison temperature, where P r P represents the comparative pressure, and P represents the actual pressure. c T represents the critical pressure.r T represents the comparison temperature, and T represents the actual temperature. c This indicates the critical temperature.

[0056] Step S4: According to the high-pressure natural gas compressibility factor regression formula Z = P r (A·T r +B)+C·T r +D calculates the compressibility factor of the high-pressure natural gas, where Z represents the compressibility factor, and P r The relative pressure is dimensionless; T r The reference temperature is dimensionless; A, B, C, and D represent variable coefficients that vary with the reference pressure.

[0057] Specifically, A, B, C, and D represent the way in which the relative pressure changes as described below:

[0058] When 5.4 < P r When ≤7.7, A=0.04842, B=-0.03494, C=-0.12493, D=0.86134.

[0059] When 7.7 < P r When ≤10.0, A=-0.07087, B=0.16140, C=0.75344, D=-0.58920.

[0060] When 10.0 < P r When ≤12.1, A=-0.06447, B=0.16244, C=0.70931, D=-0.63938.

[0061] When 12.1 < P r When ≤15.0, A=-0.07715, B=0.20533, C=0.86557, D=-1.16558.

[0062] The following specific embodiments further illustrate the method for predicting the compressibility factor of high-pressure natural gas according to the present invention.

[0063] It should be noted that the measured values ​​of natural gas compressibility factor involved in the following embodiments are taken from laboratory data or calculated by the Sour PR model of Aspen HYSYS software.

[0064] Example 1

[0065] Taking four groups of high-pressure natural gas samples tested in the laboratory as examples, the composition of these high-pressure natural gas samples is shown in Table 1.

[0066] Table 1. Composition information of high-pressure natural gas samples

[0067]

[0068] Based on the calculation formulas for the critical pressure and critical temperature of high-pressure natural gas and n is set to 13. Therefore, the critical pressure P of the four natural gas streams is calculated. c The critical pressures are 4.2379 MPa, 4.3461 MPa, 4.3456 MPa, and 4.1258 MPa, respectively; the critical temperature T0 c The values ​​are 277.0169K, 230.64534K, 253.1083K, and 274.1507K, respectively.

[0069] The actual pressure P tested ranged from 24 to 32 MPa, and the actual temperature T ranged from 382.62 to 412.39 K. Correspondingly, the comparative pressure P of the high-pressure natural gas... r The range is 5.4 to 7.7, with a comparison temperature T. r If the range is 1.38 to 1.49, then the values ​​of the variable coefficients are A = 0.04842, B = -0.03494, C = -0.12493, and D = 0.86134. The specific comparative pressure P under the test conditions... r and comparison temperature T r The comparison of relevant information is shown in Table 2.

[0070] Table 2. High-Pressure Natural Gas Compressibility Factor and Related Information

[0071]

[0072] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0073] Example 2

[0074] Taking the four groups of natural gas calculated by the Sour PR model of Aspen HYSYS software as an example, the composition of the high-pressure natural gas sample is shown in Table 3.

[0075] Table 3. Composition information of high-pressure natural gas samples

[0076]

[0077] The critical pressure P of the four natural gas streams was calculated using the same method as in Example 1. c The critical temperatures are 4.4750 MPa, 4.2600 MPa, 4.4182 MPa, and 4.4050 MPa, respectively; the critical temperature T0 c The corresponding values ​​are 241.0508K, 268.4968K, 234.4875K, and 235.0801K.

[0078] The software simulates the actual pressure P, the actual temperature T, and the corresponding natural gas comparative pressure P. r Comparison temperature T r The range is the same as in Example 1, so the values ​​of the variable coefficients are A = 0.04842, B = -0.03494, C = -0.12493, and D = 0.86134. The specific comparative pressure P under the simulated working condition... r and comparison temperature T r The relevant information is shown in Table 4.

[0079] Table 4. High-Pressure Natural Gas Compressibility Factor and Related Information

[0080]

[0081] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0082] Example 3

[0083] Taking the four groups of natural gas tested in the laboratory in Example 1 as an example, the calculated critical pressure and critical temperature values ​​of the four natural gas streams are consistent with those in the Example 1.

[0084] The actual pressure P tested ranged from 33 to 43 MPa, and the actual temperature T tested ranged from 382.62 to 412.39 K; the corresponding comparative pressure P of the natural gas was... r The range is 7.7–10.0, with a comparison temperature T. r If the range is 1.38 to 1.49, then the variable coefficients are A = -0.07087, B = 0.16140, C = 0.75344, and D = -0.58920. The comparative pressure P under the test conditions... r and comparison temperature T r The relevant information is shown in Table 5.

[0085] Table 5. High-Pressure Natural Gas Compressibility Factor and Related Information

[0086]

[0087]

[0088] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0089] Example 4

[0090] Taking the four groups of natural gas calculated using the Sour PR model of the Aspen HYSYS software in Example 2 as examples, the critical pressure P of the four natural gas streams was calculated. c With critical temperature T c The value is consistent with that of Example 2.

[0091] The software simulates the actual pressure P, the actual temperature T, and the corresponding natural gas comparative pressure P. r Comparison temperature T r The range is the same as in Example 3, so the variable coefficients are A = -0.07087, B = 0.16140, C = 0.75344, and D = -0.58920. The specific comparative pressure P under the simulated working condition... r and comparison temperature T r The relevant information is shown in Table 6.

[0092] Table 6. High-Pressure Natural Gas Compressibility Factor and Related Information

[0093]

[0094] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0095] Example 5

[0096] Taking the four groups of natural gas tested in the laboratory in Example 1 as examples, the critical pressure P of the four natural gas streams was calculated. c With critical temperature T c The value is consistent with that of Example 1.

[0097] The actual pressure P tested ranged from 43 to 54 MPa, and the actual temperature T tested ranged from 382.62 to 412.39 K; the corresponding comparative pressure P of the natural gas was... r The range is 10.0 to 12.1, with a comparison temperature T. r If the range is 1.38 to 1.49, then the variable coefficients are A = -0.06447, B = 0.16244, C = 0.70931, and D = -0.63938. The specific comparative pressure P under the test conditions... r and comparison temperature T r The relevant information is shown in Table 7.

[0098] Table 7. High-Pressure Natural Gas Compressibility Factor and Related Information

[0099]

[0100] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0101] Example 6

[0102] Taking the four groups of natural gas calculated using the Sour PR model of the Aspen HYSYS software in Example 2 as examples, the critical pressure P of the four natural gas streams was calculated. c With critical temperature T c The value is consistent with that of Example 2.

[0103] The software simulates the actual pressure P, the actual temperature T, and the corresponding natural gas comparative pressure P. r Comparison temperature T r The range is the same as in Example 5, so the variable coefficients are A = -0.06447, B = 0.16244, C = 0.70931, and D = -0.63938. The specific comparative pressure P under the simulated working condition... r and comparison temperature T r The relevant information is shown in Table 8.

[0104] Table 8. High-Pressure Natural Gas Compressibility Factor and Related Information

[0105]

[0106]

[0107] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0108] Example 7

[0109] Taking the four groups of natural gas tested in the laboratory in Example 1 as examples, the critical pressure P of the four natural gas streams was calculated. c With critical temperature T c The value is consistent with that of Example 1.

[0110] The actual pressure P tested ranged from 54 to 61 MPa, and the actual temperature T tested ranged from 382.62 to 412.39 K; the corresponding comparative pressure P of the natural gas was... r The range is 12.1–14.5, with a comparison temperature T. r If the range is 1.38 to 1.49, then the values ​​of the variable coefficients are A = -0.07715, B = 0.20533, C = 0.86557, and D = -1.16558. The specific comparative pressure P under the test conditions... r and comparison temperature T r The relevant information is shown in Table 9.

[0111] Table 9. High-Pressure Natural Gas Compressibility Factor and Related Information

[0112]

[0113] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0114] Example 8

[0115] Taking the four groups of natural gas calculated using the Sour PR model of the Aspen HYSYS software in Example 2 as examples, the critical pressure P of the four natural gas streams was calculated. c With critical temperature T c The value is consistent with that of Example 2.

[0116] The software simulates the actual pressure P, the actual temperature T, and the corresponding natural gas comparative pressure P. r Comparison temperature T r The range is the same as in Example 7, so the variable coefficients are A = -0.07715, B = 0.20533, C = 0.86557, and D = -1.16558. The specific comparative pressure P under the simulated working condition... r and comparison temperature T r The relevant information is shown in Table 10.

[0117] Table 10. High-Pressure Natural Gas Compressibility Factor and Related Information

[0118]

[0119] Therefore, as can be seen from the table above, the calculation results of the method of the present invention are significantly better than those of the GaPal formula and are closer to the measured values.

[0120] like Figure 2 As shown, in one embodiment, the high-pressure natural gas compressibility factor prediction system of the present invention includes an acquisition module 21, a first calculation module 22, a second calculation module 23, and a prediction module 24.

[0121] The acquisition module 21 is used to acquire the composition information, actual pressure, and actual temperature of high-pressure natural gas.

[0122] The first calculation module 22 is connected to the acquisition module 21 and is used to calculate the critical pressure and critical temperature of the high-pressure natural gas based on the component information.

[0123] The second calculation module 23 is connected to the acquisition module 21 and the first calculation module 22, and is used to calculate the comparative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure, and to calculate the comparative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature.

[0124] The prediction module 24 is connected to the second calculation module 23 and is used to calculate the high-pressure natural gas compressibility factor regression formula Z = P. r (A·T r +B)+C·T r +D calculates the compressibility factor of the high-pressure natural gas, where Z represents the compressibility factor, and P r T represents the comparative pressure. r The reference temperature is represented by A, B, C, and D, which are variable coefficients that vary with the reference pressure.

[0125] The structure and principle of the acquisition module 21, the first calculation module 22, the second calculation module 23 and the prediction module 24 correspond one-to-one with the steps in the above-mentioned high-pressure natural gas compressibility factor prediction method, so they will not be described again here.

[0126] It should be noted that the division of the various modules in the above device is merely a logical functional division. In actual implementation, they can be fully or partially integrated into a single physical entity, or they can be physically separated. Furthermore, these modules can be implemented entirely in software via processing element calls; they can be fully implemented in hardware; or some modules can be implemented by processing element calls to software, while others are implemented in hardware. For example, module x can be a separate processing element, or it can be integrated into a chip in the above device. Alternatively, it can be stored as program code in the memory of the above device, and its function can be called and executed by a processing element of the device. The implementation of other modules is similar. Moreover, these modules can be fully or partially integrated together, or they can be implemented independently. The processing element mentioned here can be an integrated circuit with signal processing capabilities. In the implementation process, each step of the above method or each of the above modules can be completed through the integrated logic circuits in the hardware of the processor element or through software instructions.

[0127] For example, these modules can be one or more integrated circuits configured to implement the above methods, such as one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), or one or more Field Programmable Gate Arrays (FPGAs). As another example, when a module is implemented using processing element scheduler code, the processing element can be a general-purpose processor, such as a Central Processing Unit (CPU) or other processor capable of calling program code. Furthermore, these modules can be integrated together to form a system-on-a-chip (SOC).

[0128] The storage medium of this invention stores a computer program, which, when executed by a processor, implements the aforementioned method for predicting the compressibility factor of high-pressure natural gas. The storage medium includes various media capable of storing program code, such as ROM, RAM, magnetic disk, USB flash drive, memory card, or optical disk.

[0129] like Figure 3 As shown, in one embodiment, the high-pressure natural gas compressibility factor prediction terminal of the present invention includes a processor 31 and a memory 32.

[0130] The memory 32 is used to store computer programs.

[0131] The memory 32 includes various media capable of storing program code, such as ROM, RAM, magnetic disk, USB flash drive, memory card, or optical disk.

[0132] The processor 31 is connected to the memory 32 and is used to execute the computer program stored in the memory 32 so that the high-pressure natural gas compressibility factor prediction terminal performs the above-described high-pressure natural gas compressibility factor prediction method.

[0133] Preferably, the processor 31 can be a general-purpose processor, including a central processing unit (CPU), a network processor (NP), etc.; it can also be a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0134] In summary, the high-pressure natural gas compressibility factor prediction method, system, storage medium, and terminal of this invention employ a variable coefficient in their high-pressure natural gas compressibility factor regression formula. This variable coefficient changes according to the relative pressure of the natural gas, effectively expanding the applicability. Compared to the existing GaPal formula, the calculation process is simpler, and the prediction results are closer to the actual high-pressure natural gas compressibility factor. It can better fit and predict the variation of the high-pressure natural gas compressibility factor with pressure and temperature, solving the problems of inconvenient calculation, unclear applicable conditions, and large deviations in the existing GaPal formula. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0135] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A method for predicting the compressibility factor of high-pressure natural gas, characterized in that: Includes the following steps: Obtain information on the composition, actual pressure, and actual temperature of high-pressure natural gas; The critical pressure and critical temperature of the high-pressure natural gas are calculated based on the component information. The comparative pressure of the high-pressure natural gas is calculated based on the actual pressure and the critical pressure, and the comparative temperature of the high-pressure natural gas is calculated based on the actual temperature and the critical temperature. According to the regression formula of high-pressure natural gas compressibility factor Calculate the compressibility factor of the high-pressure natural gas, where This represents the compression factor. This indicates the comparative pressure. This indicates the comparison temperature. This represents a variable coefficient that varies with the aforementioned comparative pressure; When 5.4 < When ≤7.7, A=0.04842, B=-0.03494, C=-0.12493, D=0.86134; When 7.7 < When ≤10.0, A=-0.07087, B=0.16140, C=0.75344, D=-0.58920; When 10.0 < When ≤12.1, A=-0.06447, B=0.16244, C=0.70931, D=-0.63938; When 12.1 < When ≤15.0, A=-0.07715, B=0.20533, C=0.86557, D=-1.16558.

2. The method for predicting the compressibility factor of high-pressure natural gas according to claim 1, characterized in that: The component information includes the number of components in the high-pressure natural gas, the mole fraction of each component in the natural gas, and the critical pressure and critical temperature of each component. Calculating the critical pressure and critical temperature of the high-pressure natural gas based on the component information includes the following steps: according to Calculate the critical pressure; where This indicates the mole fraction of a single component within the natural gas. This indicates the quantity of components in the high-pressure natural gas. This represents the critical pressure. This represents the critical pressure of component i; according to Calculate the critical temperature, where This indicates the critical temperature. This represents the critical temperature of component i.

3. The method for predicting the compressibility factor of high-pressure natural gas according to claim 1, characterized in that: according to Calculate the comparative pressure, based on Calculate the comparison temperature, where This indicates the comparative pressure. Indicates the actual pressure, This represents the critical pressure. This indicates the comparison temperature. This indicates the actual temperature. This indicates the critical temperature.

4. A system for predicting the compressibility factor of high-pressure natural gas, characterized in that: It includes an acquisition module, a first calculation module, a second calculation module, and a prediction module; The acquisition module is used to acquire the composition information, actual pressure, and actual temperature of high-pressure natural gas; The first calculation module is used to calculate the critical pressure and critical temperature of the high-pressure natural gas based on the component information; The second calculation module is used to calculate the comparative pressure of the high-pressure natural gas based on the actual pressure and the critical pressure, and to calculate the comparative temperature of the high-pressure natural gas based on the actual temperature and the critical temperature. The prediction module is used to calculate the high-pressure natural gas compressibility factor regression formula. Calculate the compressibility factor of the high-pressure natural gas, where This represents the compression factor. This indicates the comparative pressure. This indicates the comparison temperature. This represents a variable coefficient that varies with the aforementioned comparative pressure; When 5.4 < When ≤7.7, A=0.04842, B=-0.03494, C=-0.12493, D=0.86134; When 7.7 < When ≤10.0, A=-0.07087, B=0.16140, C=0.75344, D=-0.58920; When 10.0 < When ≤12.1, A=-0.06447, B=0.16244, C=0.70931, D=-0.63938; When 12.1 < When ≤15.0, A=-0.07715, B=0.20533, C=0.86557, D=-1.16558.

5. A storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the program implements the method for predicting the compressibility factor of high-pressure natural gas as described in any one of claims 1 to 3.

6. A terminal for predicting the compressibility factor of high-pressure natural gas, characterized in that, include: Processor and memory; The memory is used to store computer programs; The processor is used to execute the computer program stored in the memory to cause the high-pressure natural gas compressibility factor prediction terminal to perform the high-pressure natural gas compressibility factor prediction method according to any one of claims 1 to 3.

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