A wet natural gas metering method based on a reduced sliding speed analogy

Abstract

This invention discloses a method for metering wet natural gas based on fitting a modified slip ratio. First, the relationship between the gas Froude number, Venturi differential pressure, and Venturi pressure loss is fitted using known data to obtain a formula for calculating the gas Froude number. Then, the known data is partitioned according to the magnitude of the gas Froude number, and segmented fitting is performed to obtain segmented formulas for calculating the modified slip ratio under different gas Froude number conditions. Next, formulas for calculating dryness fraction and modified slip ratio are fitted separately. Finally, based on the formulas for calculating the gas Froude number, modified slip ratio, artificial height factor, and dryness fraction, some necessary real-time data is collected to calculate the real-time flow rate of wet gas. The significant advantage of this invention is that it uses known data for fitting, collects necessary data based on Venturi sampling, and calculates the flow rate data of wet gas, eliminating reliance on X-ray flow meters; it has the advantages of accurate measurement, small error, and no radioactive pollution.

Description

Technical Field

[0001] This invention relates to natural gas extraction engineering, and more specifically to a flow measurement method during the natural gas extraction process. Background Technology

[0002] Compared to oil, natural gas has the advantages of being low-carbon and efficient, making it a cleaner energy source; it is also an important transitional resource for achieving carbon neutrality in the future. The world has already increased its efforts in natural gas extraction.

[0003] Moist gas flow meters are crucial equipment for natural gas extraction, providing vital real-time metering data for reservoir management and enhanced oil recovery. There are two main technologies for moist gas flow meters: one is the "Venturi + Gamma Ray" technology, and the other is the "V-cone + Gamma Ray" technology. Both technologies require the two metering methods to work together, combining their respective data to calculate the flow rate of moist gas (gas-liquid two-phase flow).

[0004] However, although the above two technologies have wide applications, the application of existing moisture flow meters is limited in some areas due to safety regulations on gamma radiation sources; therefore, there is a need to develop non-radiation moisture flow metering technologies.

[0005] As a mature existing technology, the basic principle of Venturi measurement technology is as follows: Figure 1 Pressure differences DP1 were measured at the upstream and throat (2, 3) of the Venturi, and pressure drops PL were measured at the upstream and downstream (2, 4) of the Venturi. When moisture flows within the Venturi tube, the pressure initially decreases and then recovers. Figure 2 As shown. Summary of the Invention

[0006] In view of the above reasons, the present invention provides a wet natural gas metering method based on the fitting of the converted slip ratio, which only uses a basic Venturi flow meter for virtual metering, thus eliminating the dependence on X-ray flow meters; in practical applications, it has the advantages of accurate metering, small error and no radioactive pollution, and has practical application value and significance.

[0007] The main technical solution adopted in this invention is carried out according to the following steps:

[0008] First, the relationship between the gas Froude number and the Venturi differential pressure and Venturi pressure drop is fitted using known data to obtain the formula for calculating the gas Froude number, as follows:

[0009] Step 1: Obtain the fitted array;

[0010] The fitted array includes several one-to-one corresponding gas Froude numbers Frg, Venturi pressure loss PL, Venturi differential pressure DP1, equivalent slip ratio SS, dryness fraction X, and artificial height factor OR.

[0011] Step 2: Fit the relationship between the gas Froude number Frg and the Venturi pressure drop PL and Venturi differential pressure DP1 according to the following formula (1);

[0012] Frg=F(DP3), formula (1);

[0013] Wherein, DP3 = ​​DP1 - PL;

[0014] The formula for calculating the gas Froude number was obtained through fitting.

[0015] The known data is then divided into sections according to the gas Froude number. The relationship between the slip ratio and the Venturi differential pressure and Venturi pressure loss is then fitted piecewise within each section of the known data. The piecewise calculation formulas for the slip ratio under different gas Froude numbers are as follows:

[0016] Step 3: According to the data size of the gas Frg, the fitting data group is divided into three segments: high Frg segment, medium Frg segment, and low Frg segment.

[0017] According to the segment to which the fitted data group belongs, the relationship between the slip ratio SS and the Venturi pressure loss PL and the Venturi differential pressure DP1 is calculated piecewise, as shown in the following formula group (2):

[0018]

[0019] in:

[0020] x1 and x2 are both natural numbers, and x1 < x2;

[0021] k = DP1 / DP3;

[0022] The formula for calculating the equivalent sliding speed in segments was obtained by fitting the data.

[0023] Then, by fitting the relationships between the virtual height factor (OR), dryness (X), and calculated slip ratio (SS) of the paper, the formulas for calculating dryness and calculated slip ratio are obtained:

[0024] Step 4: Fit the relationship between the artificial height factor OR and the reduced slip ratio SS according to the following formula (3):

[0025] OR=f4(SS), formula (3);

[0026] The formula for calculating the inflated factor is obtained;

[0027] The relationship between dryness fraction X and reduced slip ratio SS is fitted according to the following formula (4):

[0028] X = f5(SS), formula (4);

[0029] The formula for calculating dryness fraction is obtained;

[0030] Finally, based on the formulas for calculating the gas Froude number, the equivalent slip ratio, the virtual height factor, and the dryness fraction, some necessary real-time data are collected to calculate the real-time flow rate of the moisture, specifically:

[0031] Step 5: Obtain the calculation array for the moisture to be measured;

[0032] The computation array includes several one-to-one corresponding real-time Venturi pressure loss PLs. s Real-time Venturi differential pressure Real-time gas phase density ρ g ;

[0033] Calculate real-time k according to the following formula (5) s value:

[0034]

[0035] Calculate the real-time value according to the following formula (6) value:

[0036]

[0037] After obtaining the above data, first utilize real-time... The real-time gas Froude number is calculated from the data. Following the same rules, the range of the real-time data is defined based on the magnitude of the real-time gas Froude number. The relevant data is then substituted into the formula for calculating the reduced slip ratio to calculate the real-time reduced slip ratio. Based on the reduced slip ratio, the real-time virtual height factor and dryness fraction are calculated. Specifically:

[0038] Step 6: Calculate the real-time artificially inflated factor OR s and real-time dryness X s ;

[0039] The real time Substituting the value into the gas Froude number calculation formula obtained in step two, we obtain the real-time gas Froude number Frg. s Comparing Frg s The size of the three values, x1, x2, and x3, is used as the standard to determine the segment to which the calculation array belongs;

[0040] The real-time k s Substitute the value into the corresponding segment in the formula for calculating the converted slip ratio obtained in step three, and calculate the real-time converted slip ratio SS. s ;

[0041] Real-time converted slip ratio SS s Substituting the formula for calculating the artificially inflated factor obtained in step four, the real-time artificially inflated factor OR is calculated. s ;

[0042] Real-time converted slip ratio SS s Substituting the formula for calculating dryness obtained in step four, the real-time X is calculated. s ;

[0043] Finally, by overestimating the gas mass flow rate using the real-time calibrated gas phase density, the real-time gas and liquid phase mass flow rates are calculated:

[0044] Step 7: Calculate the overestimated gas mass flow rate M according to the following formula (7). tp ;

[0045]

[0046] Where: C and E are constants, and d is the diameter of the Venturi throat;

[0047] Step 8: Calculate the real-time gas phase mass flow rate M of the moisture to be measured according to the following formula (8). g :

[0048] M g =M tp / OR s , formula (8);

[0049] Step 9: Calculate the real-time liquid phase mass flow rate M of the moisture to be measured according to the following formula (9). l :

[0050] Attached Figure Description

[0051] Figure 1 A schematic diagram of the internal structure of a Venturi tube;

[0052] Figure 2 This is a schematic diagram showing the pressure changes as moisture flows inside a Venturi tube.

[0053] Figure 3 The Frg-DP3 curve is shown for the test case.

[0054] Figure 4 The SS-k curve obtained by fitting the high Frg segment corresponding to the experimental example;

[0055] Figure 5 The SS-k curve obtained by fitting the Frg segment corresponding to the experimental example;

[0056] Figure 6 The SS-k curve obtained by fitting the low Frg segment corresponding to the experimental example;

[0057] Figure 7 The OR-SS curve obtained by fitting the experimental cases;

[0058] Figure 8 The X-SS curve obtained by fitting the experimental example. Detailed Implementation

[0059] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0060] Example 1:

[0061] A wet natural gas metering method based on fitting the converted slip ratio is performed according to the following steps:

[0062] Step 1: Obtain the fitted array;

[0063] The fitted array includes several one-to-one corresponding gas Froude numbers Frg, Venturi pressure loss PL, Venturi differential pressure DP1, equivalent slip ratio SS, dryness fraction X, and artificial height factor OR.

[0064] Step 2: Fit the relationship between the gas Froude number Frg and the Venturi pressure drop PL and Venturi differential pressure DP1 according to the following formula (1);

[0065] Frg=F(DP3), formula (1);

[0066] Wherein, DP3 = ​​DP1 - PL;

[0067] The formula for calculating the gas Froude number was obtained through fitting.

[0068] Step 3: Based on the size of the gas Frg data, manually set the division range and divide the fitted data group into three segments: high Frg segment, medium Frg segment, and low Frg segment.

[0069] According to the segment to which the fitted data group belongs, the relationship between the slip ratio SS and the Venturi pressure loss PL and the Venturi differential pressure DP1 is calculated piecewise, as shown in the following formula group (2):

[0070]

[0071] in:

[0072] x1 and x2 are both natural numbers, and x1 < x2;

[0073] k = DP1 / DP3;

[0074] The formula for calculating the equivalent sliding speed in segments was obtained by fitting the data.

[0075] Step 4: Fit the relationship between the artificial height factor OR and the reduced slip ratio SS according to the following formula (3):

[0076] OR=f4(SS), formula (3);

[0077] The formula for calculating the inflated factor is obtained;

[0078] The relationship between dryness fraction X and reduced slip ratio SS is fitted according to the following formula (4):

[0079] X = f5(SS), formula (4);

[0080] The formula for calculating dryness fraction is obtained;

[0081] Step 5: Obtain the calculation array for the moisture to be measured;

[0082] The computation array includes several one-to-one corresponding real-time Venturi pressure loss PLs. s Real-time Venturi differential pressure Real-time gas phase density ρ g ;

[0083] Calculate real-time k according to the following formula (5) s value:

[0084]

[0085] Calculate the real-time value according to the following formula (6) value:

[0086]

[0087] Step 6: Calculate the real-time artificially inflated factor OR s and real-time dryness X s ;

[0088] The real time Substituting the value into the gas Froude number calculation formula obtained in step two, we obtain the real-time gas Froude number Frg. s Comparing Frg s The size of the three values, x1, x2, and x3, is used as the standard to determine the segment to which the calculation array belongs;

[0089] The real-time k s Substitute the value into the corresponding segment in the formula for calculating the converted slip ratio obtained in step three, and calculate the real-time converted slip ratio SS. s ;

[0090] Real-time converted slip ratio SS s Substituting the formula for calculating the artificially inflated factor obtained in step four, the real-time artificially inflated factor OR is calculated. s ;

[0091] Real-time converted slip ratio SS s Substituting the formula for calculating dryness obtained in step four, the real-time X is calculated. s ;

[0092] Step 7: Calculate the overestimated gas mass flow rate M according to the following formula (7). tp ;

[0093]

[0094] Where: C and E are constants, and d is the diameter of the Venturi throat;

[0095] Step 8: Calculate the real-time gas phase mass flow rate M of the moisture to be measured according to the following formula (8). g :

[0096] M g =M tp / OR s , formula (8);

[0097] Step 9: Calculate the real-time liquid phase mass flow rate M of the moisture to be measured according to the following formula (9). l :

[0098]

[0099] Example 2:

[0100] The only difference between this embodiment and embodiment 1 is that in step two, the fitting is performed according to the following formula (1):

[0101] Frg=F(DP3=a1*DP3 3 +b1*DP3 2 +c1*DP3+d1, formula (1);

[0102] Where a1, b1, c1, and d1 are all natural numbers, and can be fitted by substituting several Frg and DP3 values;

[0103] Example 3:

[0104] The only difference between this embodiment and embodiment 1 is that in step three, segmented fitting is performed according to the following formula group (2):

[0105]

[0106] Group (2);

[0107] Where a2, a3, a4, a5, b2, b3, b4, b5, c2, and c3 are all natural numbers, and the specific parameters can be obtained by fitting several converted slip ratios SS with Venturi pressure loss PL and Venturi differential pressure DP1.

[0108] Example 4:

[0109] The only difference between this embodiment and embodiment 1 is that in step four, the formula for calculating the artificially inflated factor is obtained by fitting the following formula (3):

[0110]

[0111] Among them, a6, b6, and c6 are all natural numbers, obtained by fitting the artificial height factor OR and the reduced slip ratio SS;

[0112] The formula for calculating dryness is obtained by fitting the following formula (4):

[0113]

[0114] Among them, a7, b7, and c7 are all natural numbers, obtained by fitting the dryness fraction X and the equivalent slip ratio SS.

[0115] Example 5:

[0116] A wet natural gas metering method based on fitting the converted slip ratio is carried out according to the following steps:

[0117] Step 1: Obtain the fitted array;

[0118] The fitted array includes several one-to-one corresponding gas Froude numbers Frg, Venturi pressure loss PL, Venturi differential pressure DP1, equivalent slip ratio SS, dryness fraction X, and artificial height factor OR.

[0119] Step 2: Fit the relationship between the gas Froude number Frg and the Venturi pressure drop PL and Venturi differential pressure DP1 according to the following formula (1);

[0120] Frg=F(DP3=a1*DP3 3 +b1*DP3 2 +c1*DP3+d1, formula (1);

[0121] Wherein, DP3 = ​​DP1 - PL;

[0122] a1, b1, c1, and d1 are all natural numbers. By substituting several Frg and DP3 values, the specific parameters can be obtained through fitting.

[0123] From this, the formula for calculating the gas Froude number can be obtained by fitting the formula.

[0124] Step 3: Based on the size of the gas Frg data, manually set the division range and divide the fitted data group into three segments: high Frg segment, medium Frg segment, and low Frg segment.

[0125] According to the segment to which the fitted data group belongs, the relationship between the slip ratio SS and the Venturi pressure loss PL and the Venturi differential pressure DP1 is calculated piecewise, as shown in the following formula group (2):

[0126]

[0127] in:

[0128] x1 and x2 are both natural numbers, and x1 < x2;

[0129] k = DP1 / DP3;

[0130] a2, a3, a4, a5, b2, b3, b4, b5, c2, and c3 are all natural numbers. The specific parameters can be obtained by fitting several converted slip ratios SS with Venturi pressure loss PL and Venturi differential pressure DP1.

[0131] This leads to the fitted formula for calculating the equivalent sliding speed in segments;

[0132] To further illustrate step three, consider an example with three sets of fitted arrays:

[0133] The first fitted array includes the gas Froude number Frg1, Venturi pressure drop PL1, and Venturi differential pressure DP. 1,1 1. Calculated slip ratio SS1;

[0134] The second fitted array includes the gas Froude number Frg2, Venturi pressure drop PL2, and Venturi differential pressure DP. 1,2 , Calculated slip ratio SS2;

[0135] The third fitted array includes the gas Froude number Frg3, Venturi pressure drop PL3, and Venturi differential pressure DP. 1,3 , Calculated slip ratio SS3;

[0136] After defining the range for Frg:

[0137] The first fitted array has Frg > x2, which belongs to the high Frg range;

[0138] The second fitted array has Frg≥x1 and Frg≤x2, which belongs to the middle Frg range;

[0139] The third fitted array has Frg < x1, which belongs to the low Frg range.

[0140] Then, during fitting:

[0141] The first fitted array should be according to the formula. Perform fitting;

[0142] The second fitted array should be according to the formula. Perform fitting;

[0143] The third fitted array should be according to the formula. Perform fitting;

[0144] Of course, when fitting the three segments separately, sufficient data is required to obtain the corresponding parameters;

[0145] Step 4: Fit the relationship between the artificial height factor OR and the reduced slip ratio SS according to the following formula (3):

[0146]

[0147] Among them, a6, b6, and c6 are all natural numbers, obtained by fitting the artificial height factor OR and the reduced slip ratio SS;

[0148] This leads to the formula for calculating the artificially inflated factor;

[0149] The relationship between dryness fraction X and reduced slip ratio SS is fitted according to the following formula (4):

[0150]

[0151] Where a7, b7, and c7 are all natural numbers, obtained by fitting the dryness fraction X and the equivalent slip ratio SS; the dryness fraction calculation formula is obtained from this fitting.

[0152] Step 5: Obtain the calculation array for the moisture to be measured;

[0153] The computation array includes several one-to-one corresponding real-time Venturi pressure loss PLs. s Real-time Venturi differential pressure Real-time gas phase density ρ g ;

[0154] Calculate real-time k according to the following formula (5) s value:

[0155]

[0156] Calculate the real-time value according to the following formula (6) value:

[0157]

[0158] Step 6: Calculate the real-time artificially inflated factor OR s and real-time dryness X s ;

[0159] The real time Substituting the value into the gas Froude number calculation formula obtained in step two, we obtain the real-time gas Froude number Frg. s Comparing Frg s The size of the three values, x1, x2, and x3, is used as the standard to determine the segment to which the calculation array belongs;

[0160] The real-time k s Substitute the value into the corresponding segment in the formula for calculating the converted slip ratio obtained in step three, and calculate the real-time converted slip ratio SS. s ,Right now:

[0161] When Frg s When x > 2, the calculation array it belongs to is within the high Frg range, and the relevant data (k) s ) should be substituted Calculate the real-time equivalent slip ratio (at this time, all parameters in the formula are known);

[0162] When Frg≥x1 and Frg≤x2, the calculation array it belongs to is within the range of the middle Frg interval, and the relevant data (k) s ) should be substituted Calculate the real-time equivalent slip ratio (at this time, all parameters in the formula are known);

[0163] When Frg < x1, the calculation array it belongs to is within the low Frg range, and the relevant data (k) s ) should be substituted Calculate the real-time equivalent slip ratio (at this time, all parameters in the formula are known);

[0164] The real-time converted slip ratio SS obtained through the above steps s Substituting the formula for calculating the artificially inflated factor obtained in step four, the real-time artificially inflated factor OR is calculated. s ;

[0165] Real-time converted slip ratio SS s Substituting the values ​​into the dryness calculation formula obtained in step four, the real-time dryness X is calculated. s ;

[0166] Step 7: Calculate the overestimated gas mass flow rate M according to the following formula (7). tp ;

[0167]

[0168] in:

[0169]

[0170] β = d / D;

[0171] C is the Venturi outflow coefficient;

[0172] d is the diameter of Venturi's throat;

[0173] D is the diameter of the straight section of the Venturi inlet pipe;

[0174] Step 8: Calculate the real-time gas phase mass flow rate M of the moisture to be measured according to the following formula (8). g :

[0175] M g =M tp / OR s , formula (8);

[0176] Step 9: Calculate the real-time liquid phase mass flow rate M of the moisture to be measured according to the following formula (9). l :

[0177]

[0178] Experimental example:

[0179] The experiment was conducted according to the method described in Example 5.

[0180] I. Fitting Frg to DP3;

[0181] Fit the values ​​of several gas Froude numbers Frg, Venturi pressure drop PL, and Venturi differential pressure DP1, and DP3 = ​​DP1 - PL;

[0182] We have several (Frg, DP3) coordinate points, distributed in a Cartesian coordinate system as follows: Figure 3 As shown, the relationship between the fitted Frg and DP3 is:

[0183] Frg=-5DP3 3 -0.002819DP3 2 +0.2341DP3+1.728+1.534e; its fit

[0184] Degree R 2 =0.996, where e is a natural number e.

[0185] II. Piecewise Fitting

[0186] Based on experience, if we set x1 = 3.500 and x2 = 9.170, then:

[0187] The standard for dividing high Frg sections is Frg > 9.170;

[0188] The standard for dividing the Frg interval is 3.500≤Frg≤9.170;

[0189] The criterion for dividing low Frg segments is Frg < 3.500;

[0190] Several (SS, k) coordinate points were calculated. The distribution of (SS, k) in the Cartesian coordinate system for the high, medium, and low Frg sections is as follows: Figure 4 , 5 As shown in Figure 6;

[0191] The following results were obtained by piecewise fitting of the (SS, k) coordinates of each of the above segments:

[0192]

[0193] Formula group (2);

[0194] The fit R of the above three equations 2 The values ​​are 0.990, 0.996, and 0.853 respectively.

[0195] III. Fitting the formulas for calculating the artificial height factor and dryness.

[0196] Scatter plots of several artificially high factors OR and the corresponding reduced slip ratio SS are shown below. Figure 7 The fitting yielded: goodness of fit R 2 =0.997.

[0197] Scatter plots of several dryness fractions X and corresponding equivalent slip ratios SS are shown below. Figure 8 The fitting yielded:

[0198] goodness of fit R 2 =0.997.

[0199] IV. Collect real-time data and calculate the real-time converted slip ratio SS sequentially. s Real-time artificially high factor OR s Real-time dryness X s Overestimating the gas mass flow rate M tp And calculate the real-time gas phase mass flow rate M. g and real-time liquid phase mass flow rate M l Meanwhile, using the actual gas and liquid phase mass flow rates as references, the relative error Err was calculated respectively. g and Err l The statistical results are shown in Tables 1-1, 1-2, and 1-3:

[0200] Table 1-1. Real-time gas and liquid phase mass flow rates and relative error statistics (high Frg section)

[0201]

[0202] Table 1-2. Real-time gas and liquid phase mass flow rates and relative error statistics (Frg section).

[0203]

[0204]

[0205] Table 1-3. Real-time gas and liquid phase mass flow rates and relative error statistics (low Frg range)

[0206]

[0207] As can be seen from Tables 1-1, 1-2, and 1-3, the relative error between the calculated gas phase mass flow rate and the actual value is small when using the method of Example 5, while the relative error of the liquid phase mass flow rate fluctuates more. However, for the measurement of wet gas (high gas content), the stable gas phase mass flow rate with smaller error is more practically instructive.

[0208] Beneficial effects: The method of this invention fits known data to obtain the calculation formulas for the reduced slip ratio, virtual height factor, and dryness fraction. Then, it combines the pressure data measured by the Venturi flow meter and the gas density parameters of the moisture to perform virtual measurement and calculate the flow rate data of the moisture, thus eliminating the dependence on X-ray flow meters. It has the advantages of accurate measurement, small error, and no radioactive pollution.

[0209] Finally, it should be noted that the above description is merely a preferred embodiment of the present invention. Those skilled in the art, under the guidance of the present invention, can make various similar representations without departing from the spirit and claims of the present invention, and such modifications all fall within the protection scope of the present invention.

Claims

1. A method for metering wet natural gas based on fitting a converted slip ratio, characterized in that... Follow these steps: Step 1: Obtain the fitted array; The fitting array includes several one-to-one corresponding gas Froude numbers. Venturi pressure loss Venturi differential pressure Calculated slip ratio Dryness Inflated factors ; The Venturi pressure difference was measured at the upstream and throat sections of the Venturi tube. The pressure loss of the Venturi tube was measured by taking pressure samples upstream and downstream of the tube. ; Step 2: Fit the gas Froude number according to the following formula (1) Venturi pressure loss Venturi differential pressure The relationship between them; Formula (1); in, ; The formula for calculating the gas Froude number was obtained through fitting. Step 3: According to the stated gas Froude number The data size is set to define the division range, and the fitted data group is divided into three segments, namely high... Section, Middle Section, low Section; Based on the segment to which the fitted data set belongs, the slip ratio is calculated piecewise. Venturi pressure loss Venturi differential pressure The relationship between them is shown in the following formula group (2): Formula group (2); in: All are natural numbers, and ; ； The formula for calculating the equivalent sliding speed in segments was obtained by fitting the data. Step 4: Fit the artificially inflated factor according to the following formula (3). and equivalent sliding speed ratio Relationship: Formula (3); The formula for calculating the inflated factor is obtained; The dryness is fitted according to the following formula (4). and equivalent sliding speed ratio Relationship: , formula (4); The formula for calculating dryness is obtained; Step 5: Obtain the calculation array for the moisture to be measured; The computation array includes several one-to-one corresponding real-time Venturi pressure loss calculations. Real-time Venturi differential pressure Real-time gas phase density ; Calculate the real-time value according to the following formula (5) value: , formula (5); Calculate the real-time value according to the following formula (6) value: Formula (6); Step 6: Calculate the real-time artificial inflation factor and real-time dryness ; The real time Substituting the value into the gas Froude number calculation formula obtained in step two, we obtain the real-time gas Froude number. ,Compare value, , The size of the three values ​​is used as the standard to determine the segment to which the calculation array belongs; The real time Substitute the value into the corresponding segment in the segmented calculation formula for the converted slip ratio obtained in step three to calculate the real-time converted slip ratio. ; Real-time calculation of slip ratio Substituting the formula for calculating the artificially inflated factor obtained in step four, the real-time artificially inflated factor is calculated. ; Real-time calculation of slip ratio Substituting the values ​​into the dryness calculation formula obtained in step four, the real-time dryness fraction is calculated. ; Step 7: Calculate the overestimated gas mass flow rate according to the following formula (7). ; , Official (7) in: , All are constants. The diameter of Venturi's throat; Step 8: Calculate the real-time gaseous mass flow rate of the moisture to be measured according to the following formula (8). : , formula (8); Step 9: Calculate the real-time liquid mass flow rate of the moisture to be measured according to the following formula (9). : , formula (9).

2. The wet natural gas metering method based on the fitting of the converted slip ratio according to claim 1, characterized in that: In step two, the fitting is performed according to the following formula (1): Formula (1); in, All are natural numbers, derived from the Froude number of gases. Venturi pressure loss Venturi differential pressure The results were obtained through fitting.

3. The wet natural gas metering method based on the fitting of the converted slip ratio according to claim 1, characterized in that: In step three, piecewise fitting is performed according to the following formula group (2): Formula group (2); in, , , All are natural numbers, derived from the converted slip ratio. Venturi pressure loss Venturi differential pressure The results were obtained through fitting.

4. The wet natural gas metering method based on the fitting of the converted slip ratio according to claim 1, characterized in that: In step four, the formula for calculating the artificially inflated factor is obtained by fitting the following formula (3): Formula (3); in, , , All are natural numbers, due to inflated factors. and equivalent sliding speed ratio The results were obtained through fitting. The formula for calculating dryness is obtained by fitting the following formula (4): , Official (4) in, , , All are natural numbers, determined by dryness. and equivalent sliding speed ratio The results were obtained through fitting.

5. The wet natural gas metering method based on the fitting of the converted slip ratio according to claim 1, characterized in that: In step three, the defined range is set manually.

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