Method, system and equipment for calculating natural gas compression factor and medium

Abstract

The invention provides a method, a system, equipment and a medium for calculating a natural gas compression factor. The method comprises the following steps: obtaining a critical temperature and a critical pressure of natural gas based on collected natural gas component data; obtaining natural gas comparison temperature and comparison pressure based on the critical temperature and the critical pressure of the natural gas; fitting the natural gas comparison temperature and the comparison pressure to obtain a compression factor of the natural gas; according to the method provided by the invention, the denominator is never zero in the calculation process, the method is a completely continuous calculation method in an available range, a solution-free state is avoided, and the continuity of numerical simulation calculation is ensured; the method is particularly suitable for continuous calculation or simulation of the process of oil and gas reservoir simulation, development dynamic analysis, oil and gas well testing, oil and gas well engineering and pipeline transportation, and has the advantages of being large in range, high in precision, high in speed and small in occupied computer memory.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and particularly to a method, system, device and medium for calculating the natural gas compressibility factor. Background Art

[0002] The natural gas compressibility factor, also known as the deviation coefficient, is essentially a deviation correction coefficient between natural gas and an ideal gas; in the process of oil and gas field development, it is very necessary to perform numerical simulations on the processes of oil and gas reservoir simulation, development dynamic analysis, oil and gas well testing, oil and gas well engineering, and pipeline transportation. The numerical simulation requires the natural gas compressibility factor to calculate the temperature and pressure of the medium within the finite element. The temperature and pressure change continuously and affect each other. Once a breakpoint appears in the compressibility factor, it may cause an infinite loop in the numerical simulation process, and all previous work will be in vain; with the in-depth development of oil fields, high-temperature and high-pressure oil and gas fields are continuously discovered. In recent years, more and more oil and gas reservoirs with formation pressures and temperatures exceeding 110 MPa and 150 °C have been found. The original calculation method for the natural gas compressibility factor fitted at a reduced pressure of 0.2 to 15 and a reduced temperature of 1.05 to 3 can no longer meet the needs of oil and gas field development.

[0003] In the existing technologies, the calculation methods for the natural gas compressibility factor include: The first type of technology mainly includes "Calculation Method of Compressibility Factor (CN110516794A)", "Calculation Method of Natural Gas Compressibility Factor (CN106525180A)", "Calculation Accuracy Method and Application of Compressibility Factor of Natural Gas Flow Computer (CN110738579A)", and "A Fast Calculation Method for High-Precision Natural Gas Compressibility Factor (CN115034063A)", etc. These calculation methods are all based on the virial equation of AGA8 and are recommended to be applicable within a range not exceeding 12 MPa in pressure, not exceeding 65 °C in temperature, and not exceeding 0.8 in natural gas relative density according to the ISO international standard. Obviously, these calculation methods cannot meet the requirements of oil field development.

[0004] The second type of technology mainly includes "A Calculation Method for Ultra-High Pressure Natural Gas Compressibility Factor (CN114372369A)" and "A Method for Obtaining Natural Gas Compressibility Factor (CN114186165A)", etc. The former regresses the high-pressure part of the Standing-Katz chart to form a calculation method, with an applicable temperature range of 347.70 - 437.65 K and a pressure range of 70 MPa - 120 MPa; the latter mainly focuses on heavy hydrocarbons (C7+) in natural gas and calculates the calculation method for the natural gas compressibility factor of ultra-high pressure gas reservoirs based on parameters such as the mole fraction, critical pressure, critical temperature, and acentric factor of each component, as well as the gravitational coefficient and repulsive coefficient of the natural gas mixture. Obviously, its disadvantages are that there are many input parameters, the calculation process is troublesome, there are continuity problems, and there are many unsolvable points.

[0005] The third type of technology is mainly the method of Shell Oil Company. This method is one of the most accurate methods for calculating the compression factor at present. However, its drawback is that when the reduced temperature exceeds 2 (about 400K), the error is very large, and the maximum is close to 300%.

[0006] Therefore, this application anticipates a method that can continuously and accurately collect the compression factor of natural gas. Summary of the Invention

[0007] In view of the problems existing in the prior art, the present invention provides a method, system, device and medium for calculating the compression factor of natural gas, which can continuously and accurately collect the compression factor of natural gas.

[0008] The present invention is realized through the following technical solutions:

[0009] A method for calculating the compression factor of natural gas includes the following steps:

[0010] Obtain the critical temperature and critical pressure of natural gas based on the collected natural gas component data;

[0011] Obtain the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas;

[0012] Fit the reduced temperature and reduced pressure of natural gas to obtain the compression factor of natural gas.

[0013] Further, the process of obtaining the critical temperature and critical pressure of natural gas based on the collected natural gas component data is as follows:

[0014]

[0015]

[0016] In the formula, P pc is the critical pressure of natural gas, MPa; T pc is the critical temperature of natural gas, K; y i is the molar content of the i-th component, %; P ci is the critical pressure of the i-th component, MPa; T ci is the critical temperature of the i-th component, K.

[0017] Further, if the collected natural gas contains acidic gas components and the content exceeds 3%, then first obtain the pseudo-critical pressure and pseudo-critical temperature, and then correct the pseudo-critical pressure and pseudo-critical temperature to the true critical pressure and critical temperature of natural gas.

[0018] Further, the acidic gas components include hydrogen sulfide and carbon dioxide.

[0019] Further, when the content of the carbonic acid component exceeds 3%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows:

[0020]

[0021]

[0022]

[0023]

[0024] In the formula, is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

[0025] Further, if the collected natural gas contains nitrogen and the molar content of nitrogen is greater than 5%, the pseudo-critical pressure and pseudo-critical temperature are obtained first, and then the pseudo-critical pressure and pseudo-critical temperature are corrected to the true critical pressure and critical temperature of natural gas.

[0026] Further, when the molar content of nitrogen is greater than 5%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows:

[0027]

[0028]

[0029]

[0030]

[0031] In the formula, is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

[0032] Further, the process of obtaining the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas is as follows:

[0033]

[0034]

[0035] In the formula, T pr is the reduced temperature, dimensionless; P pr is the reduced pressure, dimensionless; T is the absolute temperature of natural gas, K; T pc is the critical temperature of natural gas, K; P is the absolute temperature of natural gas, MPa; P pc _ is the critical temperature of natural gas, MPa.

[0036] Furthermore, the process of fitting the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas is as follows:

[0037]

[0038] The coefficients in the formula are respectively:

[0039] a = A1[ln(P pr )] + A2[ln(P pr )] 2 + A3[ln(P pr )] 3 + A4[ln(P pr )] 4 + A5[ln(P pr )] 5 ;

[0040] b = A6 + A7[ln(P pr )] + A8[ln(P pr )] 2 + A9[ln(P pr )] 3 + A 10 [ln(P pr )] 4 ;

[0041] c = A 11 + A 12 [ln(P pr )] + A 13 [ln(P pr )] 2 + A 14 [ln(P pr )] 3 ;

[0042] d = A 15 + A 16 [ln(P pr )] + A 17 [ln(P pr )] 2 ;

[0043] e = A 18 + A 19 [ln(P pr )];

[0044] f = A 20 ;

[0045] In the formula, Z is the compressibility factor, dimensionless; A1 - A 20 are all fitting coefficients.

[0046] A system for calculating the compressibility factor of natural gas, comprising:

[0047] A collection module configured to obtain the critical temperature and critical pressure of natural gas based on the collected natural gas composition data;

[0048] A processing module configured to obtain the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas;

[0049] An output module configured to fit the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas.

[0050] A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of a method for calculating the compressibility factor of natural gas are implemented.

[0051] A computer-readable storage medium storing a computer program, wherein when the computer program is executed by a processor, the steps of a method for calculating the compressibility factor of natural gas are implemented.

[0052] Compared with the prior art, the present invention has the following beneficial technical effects:

[0053] The present invention provides a method, system, device, and medium for calculating the compressibility factor of natural gas, comprising the following steps: obtaining the critical temperature and critical pressure of natural gas based on the collected natural gas composition data; obtaining the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas; fitting the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas; in the calculation process of the method provided by the present application, the denominator will never be zero, and it is a completely continuous calculation method within the available range, without the state of no solution, ensuring the continuity of numerical simulation calculation; this method is particularly suitable for continuous calculation or simulation in the processes of oil and gas reservoir simulation, development dynamic analysis, oil and gas well testing, oil and gas well engineering, and pipeline transportation, and has the advantages of a large range, high precision, fast speed, and less computer memory occupancy. Description of the Drawings

[0054] Figure 1 It is a flowchart of a method for calculating the compressibility factor of natural gas in an embodiment of the present invention;

[0055] Figure 2 It is a comparative diagram of the cumulative frequency distribution of the absolute error of 0-10% between the method in the embodiment of the present invention and the comparative method;

[0056] Figure 3Statistical chart of relative errors between the predicted values of the method in Example 1 and the Standing-Katz standard chart data at different reduced temperatures and pressures in the embodiments of the present invention;

[0057] Figure 4 Statistical chart of relative errors between the predicted values of the method in Comparative Example 1 and the Standing-Katz standard chart data at different reduced temperatures and pressures in the embodiments of the present invention. Detailed implementation manners

[0058] The following further describes the present invention in detail with specific embodiments, which are explanations of the present invention rather than limitations.

[0059] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0060] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those clearly listed steps or units, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0061] An embodiment of the present invention provides a method for calculating the compression factor of natural gas, as Figure 1 shown, including the following steps:

[0062] Obtain the critical temperature and critical pressure of natural gas based on the collected natural gas composition data;

[0063] Obtain the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas;

[0064] Fit the reduced temperature and reduced pressure of natural gas to obtain the compression factor of natural gas.

[0065] Preferably, in this embodiment, the process of obtaining the critical temperature and critical pressure of natural gas based on the collected natural gas component data is as follows:

[0066]

[0067]

[0068] where P pc is the critical pressure of natural gas, MPa; T pc is the critical temperature of natural gas, K; y i is the molar content of the i-th component, %; P ci is the critical pressure of the i-th component, MPa; T ci is the critical temperature of the i-th component, K.

[0069] It should be noted that in this embodiment, the critical temperature of natural gas refers to the temperature at which the gas and liquid phases cannot be distinguished under a certain pressure, and the critical pressure of natural gas refers to the pressure at which the gas and liquid phases cannot be distinguished when the pressure of the gas reaches a certain value.

[0070] Preferably, in this embodiment, if the collected natural gas contains acidic components and the content exceeds 3%, then the pseudo-critical pressure and pseudo-critical temperature are first obtained, and then the pseudo-critical pressure and pseudo-critical temperature are corrected to the true critical pressure and critical temperature of natural gas; specifically, the acidic components include hydrogen sulfide and carbon dioxide.

[0071] Specifically, when the content of acidic components exceeds 3%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows:

[0072]

[0073]

[0074]

[0075]

[0076] where is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

[0077] Preferably, in this embodiment, if the collected natural gas contains nitrogen and the nitrogen molar content is greater than 5%, then the pseudo-critical pressure and pseudo-critical temperature are first obtained, and then the pseudo-critical pressure and pseudo-critical temperature are corrected to the true critical pressure and critical temperature of natural gas.

[0078] Specifically, when the molar content of nitrogen is greater than 5%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows:

[0079]

[0080]

[0081]

[0082]

[0083] In the formula, is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

[0084] It should be noted that the pseudo-critical pressure of natural gas described in this embodiment refers to the pressure at which the density of the gas is close to the liquid density at a certain temperature. This pressure is usually higher than the true critical pressure of natural gas because the density of the gas at the pseudo-critical pressure is already close to the liquid density; the pseudo-critical temperature of natural gas refers to the temperature at which the density of the gas is close to the liquid density at a certain pressure. This temperature is usually higher than the true critical temperature of natural gas because the density of the gas at the pseudo-critical temperature is already close to the liquid density.

[0085] The process of converting the pseudo-critical pressure and pseudo-critical temperature of natural gas to the true critical temperature and critical pressure needs to be corrected and adjusted. Specifically, the conversion process can be calculated and fitted according to relevant physical property equations or experimental data to obtain more accurate physical property parameters; in the conversion process, various factors need to be considered, such as the compression factor of the gas, the correction coefficients of temperature and pressure, the molecular structure of the gas, etc. By introducing these correction factors, the physical behavior of the gas at high temperature and high pressure can be more accurately described, so as to obtain the critical temperature and critical pressure closer to the actual situation.

[0086] Preferably, in this embodiment, the process of obtaining the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas is as follows:

[0087]

[0088]

[0089] In the formula, T pr is the reduced temperature, dimensionless; P pr is the reduced pressure, dimensionless; T is the absolute temperature of natural gas, K; T pc is the critical temperature of natural gas, K; P is the absolute temperature of natural gas, MPa; P pc_ is the critical temperature of natural gas, MPa.

[0090] Preferably, in this embodiment, the process of fitting the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas is as follows:

[0091]

[0092] The coefficients in the formula are respectively:

[0093] a = A1[ln(P pr )] + A2[ln(P pr )] 2 + A3[ln(P pr )] 3 + A4[ln(P pr )] 4 + A5[ln(P pr )] 5 ;

[0094] b = A6 + A7[ln(P pr )] + A8[ln(P pr )] 2 + A9[ln(P pr )] 3 + A 10 [ln(P pr )] 4 ;

[0095] c = A 11 + A 12 [ln(P pr )] + A 13 [ln(P pr )] 2 + A 14 [ln(P pr )] 3 ;

[0096] d = A 15 + A 16 [ln(P pr )] + A 17 [ln(P pr )] 2 ;

[0097] e = A 18 + A 19 [ln(P pr )];

[0098] f = A 20 ;

[0099] In the formula, Z is the compressibility factor, dimensionless; A1 - A20 All are fitting coefficients.

[0100] An embodiment provided by the present invention is as follows:

[0101] After digitizing the comparison pressure of the Standing-Katz standard chart from 0.2 to 30, 8340 groups of data such as comparison pressure, comparison temperature, and chart standard compressibility factor are obtained, as shown in the second, third, and fourth columns of Table 1.

[0102] Substitute the comparison pressure and comparison temperature into the following formula:

[0103]

[0104] The coefficients in the above formula are respectively:

[0105] a = A1[ln(P pr )] + A2[ln(P pr )] 2 + A3[ln(P pr )] 3 + A4[ln(P pr )] 4 + A5[ln(P pr )] 5

[0106] b = A6 + A7[ln(P pr )] + A8[ln(P pr )] 2 + A9[ln(P pr )] 3 + A 10 [ln(P pr )] 4

[0107] c = A 11 + A 12 [ln(P pr )] + A 13 [ln(P pr )] 2 + A 14 [ln(P pr )] 3

[0108] d = A 15 + A 16 [ln(P pr )] + A 17 [ln(P pr )] 2

[0109] e = A 18 + A19 [ln(P pr )]

[0110] f = A 20

[0111] Obtain the calculated compressibility factor of this method, and calculate the absolute error R between the calculated compressibility factor and the chart compressibility factor according to the following formula.

[0112]

[0113] Specifically, the numerical values of the fitting coefficients are shown in Table 1:

[0114] Table 1. Numerical values of fitting coefficients

[0115]

[0116]

[0117] The average of the absolute errors statistically calculated according to the above formula is 1.044236%, and the distribution diagrams of different error frequencies are shown in Figure 2 as shown. It can be seen from Figure 2 that there are 8052 groups of prediction points with an average absolute error within 5%, and the cumulative frequency is 96.55%.

[0118] Comparative Example 1:

[0119] Using the compressibility factor calculation model of Shell, 8340 groups of data digitized from the Standing-Katz standard chart are calculated, and the calculated values and absolute errors of the compressibility factor are as shown in Figure 3 as shown. The maximum absolute error exceeds 260%, and the average absolute error is 8.59%. The distribution diagrams of different error frequencies are as shown in Figure 4 as shown. It can be seen from Figure 4 that there are 6175 groups of prediction points in the comparative example with an average absolute error within 5%, and the cumulative frequency is 74.03%.

[0120] The present invention provides a system for natural gas compressibility factor, including:

[0121] A collection module configured to obtain the critical temperature and critical pressure of natural gas based on the collected natural gas composition data;

[0122] A processing module configured to obtain the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas;

[0123] An output module configured to fit the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas.

[0124] In another embodiment of the present invention, a computer device is provided. The computer device includes a processor and a memory. The memory is used to store a computer program, and the computer program includes program instructions. The processor is used to execute the program instructions stored in the computer storage medium. The processor may be a Central Processing Unit (CPU), or may also be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. It is the computing core and control core of the terminal, and is suitable for implementing one or more instructions. Specifically, it is suitable for loading and executing one or more instructions in the computer storage medium to implement the corresponding method flow or corresponding function. The processor described in the embodiment of the present invention can be used for the operation of a method for calculating the natural gas compression factor.

[0125] In another embodiment of the present invention, a storage medium is also provided, specifically a computer-readable storage medium (Memory). The computer-readable storage medium is a memory device in a computer device and is used to store programs and data. It can be understood that the computer-readable storage medium here can include both the built-in storage medium in the computer device and, of course, the extended storage medium supported by the computer device. The computer-readable storage medium provides a storage space that stores the operating system of the terminal. And in this storage space, one or more instructions suitable for being loaded and executed by the processor are also stored. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory. One or more instructions stored in the computer-readable storage medium can be loaded and executed by the processor to implement the corresponding steps of the method for calculating the natural gas compression factor in the above embodiment.

[0126] Those skilled in the art should understand that the embodiments of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk memory, CD-ROM, optical memory, etc.) that contain computer-usable program code.

[0127] The present invention is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to embodiments of the present invention. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0128] These computer program instructions can also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, such that the instructions stored in the computer-readable memory generate a manufactured article including instruction means that implement the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0129] These computer program instructions can also be loaded onto a computer or other programmable data processing device, such that a series of operation steps are executed on the computer or other programmable device to generate a computer-implemented process, and thus the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0130] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the compressibility factor of natural gas, characterized in that, Including the following steps: Obtaining the critical temperature and critical pressure of natural gas based on the collected natural gas composition data; Obtaining the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas; Fitting the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas.

2. The method for calculating the natural gas compression factor according to claim 1, wherein The process of obtaining the critical temperature and critical pressure of natural gas based on the collected natural gas composition data is as follows: where P pc is the critical pressure of natural gas, MPa; T pc is the critical temperature of natural gas, K; y i is the molar content of the i-th component, %; P ci is the critical pressure of the i-th component, MPa; T ci is the critical temperature of the i-th component, K.

3. The method for calculating the natural gas compression factor according to claim 1, wherein If the collected natural gas contains acidic components and the content exceeds 3%, then first obtain the pseudo-critical pressure and pseudo-critical temperature, and then correct the pseudo-critical pressure and pseudo-critical temperature to the true critical pressure and critical temperature of natural gas.

4. The method for calculating the natural gas compression factor according to claim 3, wherein The acidic components include hydrogen sulfide and carbon dioxide.

5. The method for calculating the natural gas compression factor according to claim 3, wherein When the content of acidic components exceeds 3%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows: wherein, is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

6. The method for calculating the natural gas compression factor according to claim 1, wherein If the collected natural gas contains nitrogen and the molar content of nitrogen is greater than 5%, then first obtain the pseudo-critical pressure and pseudo-critical temperature, and then correct the pseudo-critical pressure and pseudo-critical temperature to the true critical pressure and critical temperature of natural gas.

7. The method for calculating the natural gas compression factor according to claim 6, characterized in that, When the molar content of nitrogen is greater than 5%, the process of obtaining the pseudo-critical pressure and pseudo-critical temperature is as follows: In the formula, is the pseudo-critical pressure of natural gas, MPa; is the pseudo-critical temperature of natural gas, K.

8. The method for calculating the natural gas compression factor according to claim 1, wherein The process of obtaining the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas is as follows: where T pr is the reduced temperature, dimensionless; P pr is the reduced pressure, dimensionless; T is the absolute temperature of natural gas, K; T pc is the critical temperature of natural gas, K; P is the absolute pressure of natural gas, MPa; P pc _ is the critical pressure of natural gas, MPa.

9. The method for calculating the natural gas compression factor according to claim 1, wherein The process of fitting the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas is as follows: The coefficients in the formula are respectively: a = A1[ln(P pr )] + A2[ln(P pr )] 2 + A3[ln(P pr )] 3 + A4[ln(P pr )] 4 + A5[ln(P pr )] 5 ; b = A6 + A7[ln(P pr )] + A8[ln(P pr )] 2 + A9[ln(P pr )] 3 + A 10 [ln(P pr )] 4 ; c = A 11 + A 12 [ln(P pr )] + A 13 [ln(P pr )] 2 + A 14 [ln(P pr )] 3 ; d = A 15 + A 16 [ln(P pr )] + A 17 [ln(P pr )] 2 ; e = A 18 + A 19 [ln(P pr )]; f = A 20 ; where Z is the compressibility factor, dimensionless; A1 - A 20 are all fitting coefficients.

10. A system for natural gas compression factor, characterized in that, Based on the method for calculating the compressibility factor of natural gas according to any one of claims 1-9, including: A collection module configured to obtain the critical temperature and critical pressure of natural gas based on the collected natural gas composition data; A processing module configured to obtain the reduced temperature and reduced pressure of natural gas based on the critical temperature and critical pressure of natural gas; An output module configured to fit the reduced temperature and reduced pressure of natural gas to obtain the compressibility factor of natural gas.

11. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, the steps of the method for calculating the compressibility factor of natural gas according to any one of claims 1-9 are implemented.

12. A computer-readable storage medium storing a computer program, characterized in that, When the computer program is executed by the processor, the steps of the method for calculating the compressibility factor of natural gas according to any one of claims 1-9 are implemented.

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