Multi-phase metering modeling system and multi-phase metering method for oil well produced substances

Abstract

The invention discloses a multiphase metering modeling system and a multiphase metering method for oil well produced substances. An oil well multiphase medium extraction simulation device of the system is used for measuring throttling pressure difference signals and temperature drop amplitude before and after a gas phase and a liquid phase of different flow combinations are mixed and pass through a selected oil nozzle, and an experimental data set is obtained; the metering model building module is used for building an oil well multiphase produced medium metering model based on the experimental data set, and a gas phase mass content calculation model is used for representing the relation among the fluctuation standard deviation of the throttling pressure difference before and after the oil nozzle, the temperature drop amplitude and the gas phase mass content; the total mass flow calculation model is a linear function relation between the ratio of the arithmetic square root of the average value of the throttling pressure difference before and after the oil nozzle device to the total mass flow and the gas phase mass content. The model established by using the system can accurately and conveniently meter the oil well multiphase produced medium, is wide in application range, and is still suitable for complex working conditions such as high gas-liquid ratio; and the ground technological process is simple, and the metering cost is low.

Description

Technical Field

[0001] The invention relates to the technical field of oil well produced multiphase fluid metering, and in particular to an oil well produced multiphase metering modeling system and a multiphase metering method. Background Art

[0002] Wellhead measurement of oil well production media is an important task in reservoir dynamic analysis and production management. Accurate and timely measurement of oil well production is of great guiding significance for understanding reservoir conditions and formulating production plans, which directly affects the rational development and economic benefits of oil fields. Most of the oil well production media exist in multiphase fluids, and the measurement of multiphase media has always been the focus and difficulty of single well measurement in oil fields at home and abroad.

[0003] In the related technology, there are many ways to achieve the metering of multiphase produced media in oil wells, such as the traditional single-well separation metering method, the non-separation metering method of multiphase flowmeters, and modern software metering technology represented by power diagram metering. Summary of the invention

[0004] The inventors found that the traditional metering method of multiphase produced media in oil wells has problems such as complex ground process flow, high metering cost, and low measurement accuracy. The ground process flow of separation metering is complicated, which increases the construction investment and use cost. Although the non-separation metering of multiphase flowmeters shows superiority in terms of space occupation, the flow characteristics of the gas-liquid two-phase flow change significantly and are highly volatile, resulting in low measurement accuracy and a narrow range of applicable gas-liquid ratios; in addition, the non-separation metering device of the multiphase flowmeter generally uses microwave sensors and gamma densitometers to test the phase fraction, so the cost is relatively high. With the continuous advancement of digital construction of oil fields, there is an urgent need for an oil well metering method that simplifies the ground gathering and transportation process, has low operating costs, and can achieve continuous, automatic, accurate, and real-time measurement of production. Against this background, digital metering technology came into being, which played an important role in optimizing and simplifying the oil field gathering and transportation system, and has gradually become one of the important contents of intelligent oil field construction. In the production of single wells in conventional oil fields, software metering technology represented by power diagram metering has been widely used in pumping wells. The oil well liquid production is calculated by real-time collection and processing and analysis of oil well indicator diagram data, thereby realizing remote automatic metering of liquid production. However, the error of power diagram metering is large under high gas-liquid ratio conditions. In terms of liquid production metering of electric pump wells, considering the influence of temperature and pressure changes on the expansion coefficient of the throttling device, the conventional pressure difference method flow metering formula has been corrected based on the homogeneous flow theory to obtain higher metering accuracy. However, in the self-flowing production stage of single well production, the working conditions are complex, the gas production changes are unstable, the water content and production change rapidly and the change range is large, resulting in significant changes in flow characteristics. There is still a problem that the gas-liquid phase content after the change cannot be accurately known, resulting in large deviations in the calculation results, especially for high gas content conditions. The adaptability will be worse; and the lack of analysis of the change of the nozzle flow coefficient with the opening degree has further affected the adaptability accuracy and range of the actual single well metering.

[0005] Therefore, how to accurately and conveniently measure the multiphase produced medium of oil wells under complex working conditions such as high gas-liquid ratio is a technical problem that needs to be solved urgently.

[0006] In order to at least partially solve the technical problems existing in the prior art, the inventors have made the present invention, and through specific implementation methods, provide a multiphase metering modeling system and a multiphase metering method for oil well production, which can accurately and conveniently measure the multiphase production medium of oil wells.

[0007] In a first aspect, an embodiment of the present invention provides a multiphase metering modeling system for oil well production, including an oil well multiphase medium production simulation device and a metering model building module;

[0008] The oil well multiphase medium extraction simulation equipment includes a liquid phase supply device, a gas phase supply device, a mixer and a nozzle connection device, which is used to measure the throttling pressure difference signal and temperature drop amplitude before and after the nozzle when the gas phase and liquid phase of different flow combinations are mixed and pass through the selected nozzle to obtain an experimental data set;

[0009] The metering model establishment module is used to establish a gas phase mass content calculation model and a total mass flow calculation model for the multiphase produced medium of the oil well based on the experimental data set. The gas phase mass content calculation model is used to characterize the relationship between the standard deviation of the throttling pressure difference fluctuation before and after the nozzle, the temperature drop amplitude and the gas phase mass content of the multiphase medium; the total mass flow calculation model is a linear function between the ratio of the arithmetic square root of the mean value of the throttling pressure difference before and after the nozzle device to the total mass flow of the multiphase produced medium and the gas phase mass content of the multiphase produced medium.

[0010] In a second aspect, an embodiment of the present invention provides a multiphase metering method for oil well production, comprising:

[0011] According to the standard deviation of the throttling pressure difference fluctuation and the temperature drop amplitude before and after the oil nozzle set in the target oil well, the gas mass content calculation model is used to determine the gas mass content of the multiphase medium produced from the oil well;

[0012] According to the average value of the throttling pressure difference before and after the nozzle and the determined gas phase mass content, the total mass flow rate of the multiphase medium is obtained by using the total mass flow calculation model. The gas phase mass content calculation model and the total mass flow calculation model are both established through the above-mentioned oil well production multiphase metering modeling system.

[0013] In a third aspect, an embodiment of the present invention provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned multiphase metering method of oil well production is implemented.

[0014] In a fourth aspect, an embodiment of the present disclosure provides a server, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned multiphase metering method for oil well production when executing the program.

[0015] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0016] The multiphase metering modeling system for oil well production provided by the embodiment of the present invention includes an oil well multiphase medium production simulation device, which is used to measure the throttling pressure difference signal and temperature drop amplitude before and after the oil nozzle when the gas phase and liquid phase of different flow combinations are mixed and pass through the oil nozzle, and obtain an experimental data set; the metering model establishment module of the system is used to establish a gas phase mass content calculation model and a total mass flow calculation model for the oil well multiphase production medium based on the experimental data set. Through the model established by the system, on the basis of obtaining the average value, fluctuation standard deviation and temperature drop amplitude of the throttling pressure difference before and after the oil nozzle of the oil well, the multiphase production medium of the oil well can be accurately and conveniently metered; and the ground process flow is simple, the metering cost is low, and the measurement accuracy is high, and it is still applicable to the multiphase production medium of the oil well with a high gas-liquid ratio.

[0017] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0020] Figure 1 Schematic diagram of the structure of the multiphase measurement modeling system of oil well production in an embodiment of the present invention;

[0021] Figure 2 This is a graph showing the relationship between the nozzle flow coefficient and the opening degree in an embodiment of the present invention;

[0022] Figure 3 It is a schematic diagram of the pressure difference fluctuation over time in a throttling test of a multiphase production medium nozzle with a certain gas phase content in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the change of the nozzle throttling pressure difference fluctuation characteristics with the gas phase mass content in the embodiment of the present invention;

[0024] Figure 5 It is a schematic diagram showing the variation of the throttling temperature drop amplitude of the nozzle section with the gas phase mass content in an embodiment of the present invention;

[0025] Figure 6 Schematic diagram of the relationship between the ratio of the arithmetic square root of the nozzle throttling pressure difference to the total mass flow rate and the gas phase mass content in an embodiment of the present invention. DETAILED DESCRIPTION

[0026] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0027] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0028] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0029] In order to solve the problems of complex ground process flow, high metering cost and low measurement accuracy in the existing metering methods of multiphase produced media from oil wells, the embodiments of the present invention provide a multiphase metering modeling system and a multiphase metering method for oil well produced materials, which can accurately and conveniently meter the multiphase produced media from oil wells.

[0030] Embodiment 1

[0031] Embodiment 1 of the present invention provides a multiphase measurement modeling system for oil well production, the structure of which is shown in FIG. Figure 1 As shown, it includes an oil well multiphase medium production simulation device 1 and a metering model establishment module 2.

[0032] The oil well multiphase medium extraction simulation device 1 is used to measure the throttling pressure difference signal and temperature drop amplitude before and after the oil nozzle when the gas phase and liquid phase of different flow combinations are mixed and pass through the selected oil nozzle, so as to obtain the experimental data set.

[0033] The oil well multiphase medium production simulation device 1 comprises a liquid phase supply device 11, a gas phase supply device 12, a mixer 13 and an oil nozzle connection device 14.

[0034] The nozzle connecting device 14 is used to connect the nozzle of the selected specification. The upstream first node and the downstream second node of the nozzle connecting device 14 are respectively connected to the two ends of the differential pressure transmitter 141, and the upstream third node and the downstream fourth node of the nozzle connecting device 14 are respectively connected to the two ends of the differential temperature transmitter 142.

[0035] The upstream end of the mixer 13 is connected to the downstream ends of the liquid phase supply device 11 and the gas phase supply device 12 , and the downstream end of the mixer 13 is connected to the upstream end of the nozzle connection device 14 .

[0036] A gas phase flow meter 121 , a thermometer 122 , and a pressure gauge 123 are connected to the gas phase supply device 12 , and a liquid phase flow meter 111 is connected to the liquid phase supply device 11 .

[0037] In some embodiments, the oil well multiphase medium production simulation equipment 1 also includes a separator 15; the downstream end of the oil nozzle connecting device 14 is connected to the inlet of the separator 15; the gas phase outlet of the separator 15 is connected to the upstream end of the gas phase supply device 12, and the liquid phase outlet of the separator 15 is connected to the upstream end of the liquid phase supply device 11.

[0038] The metering model building module 2 is used to build a gas phase mass content calculation model and a total mass flow calculation model of the oil well multiphase production medium based on the experimental data set obtained by the oil well multiphase medium production simulation device 1.

[0039] Among them, the gas phase mass content calculation model is used to characterize the relationship between the standard deviation of the throttling pressure difference before and after the nozzle, the temperature drop amplitude and the gas phase mass content of the multiphase medium; the total mass flow calculation model is used to characterize the relationship between the mean value of the throttling pressure difference before and after the nozzle, the gas phase mass content of the multiphase medium and the total mass flow of the multiphase medium.

[0040] The metrology model building module 2 includes a data storage unit 21 , a metrology model building module 22 and a sampling frequency time optimization unit 23 .

[0041] The data storage unit 21 is used to configure the gas-liquid flow rate, record the hydraulic data set (differential pressure mean and fluctuation standard deviation data set matrix) and thermal data set (temperature drop value data set matrix) obtained by the test.

[0042] The metering model establishment module 22 is used to calculate the gas mass content based on the data set matrix obtained by the data storage unit 21, innovatively integrate the standard deviation of the nozzle throttling pressure difference fluctuation and the temperature drop characteristic inversion, calculate the total mass flow rate of the multiphase medium through the linear function relationship between the arithmetic square root of the mean value of the throttling pressure difference before and after the nozzle device and the total mass flow rate of the multiphase production medium and the gas mass content of the multiphase production medium, and output a multiphase production medium metering model suitable for a specific oil well (an oil well with a nozzle size consistent with the experimental nozzle size) to guide on-site metering.

[0043] The sampling frequency time optimization unit 23 is used to intelligently select and optimize the optimal pressure difference signal sampling frequency and sampling time.

[0044] An experiment to study the hydraulic and thermal characteristics of produced media under throttling conditions was carried out using an oil well multiphase medium production simulation device. The throttling pressure difference signal and the temperature drop amplitude before and after the experimental nozzle were measured when the multiphase medium with different gas mass contents was transported to the experimental nozzle, and an experimental data set was obtained. Each set of data in the experimental data set included the mass flow rate of the liquid medium and the mass flow rate of the gas medium in the multiphase medium in the experimental setting data, the gas mass content, and the corresponding experimental results. The average throttling pressure difference, the standard deviation of the throttling pressure difference and the temperature drop amplitude were also included.

[0045] 1. Description of the experimental process of hydraulic and thermal characteristics of multiphase produced fluid under nozzle throttling condition

[0046] 1. Pressure difference and temperature drop signal test

[0047] Step 1.1: Open the valve of the gas phase supply device and adjust the gas phase flow rate to a fixed value Q g1 After the gas fills the entire pipeline and the flow rate stabilizes for a period of time, the data acquisition unit records the average pressure difference signal before and after the nozzle. Pressure difference signal fluctuation standard deviation (σ ΔP ) g1,0 And the temperature drop ΔT g1,0 .

[0048] The standard deviation of pressure difference signal fluctuation σ ΔP Characterization experiment collects the fluctuation size of the pressure difference signal:

[0049]

[0050] In the formula, σ ΔP is the standard deviation of the pressure difference signal fluctuation collected during a certain set of experiments, Pa; n is the number of points of the pressure difference signal collected during a certain set of experiments, ΔP i is the pressure difference value at the i-th point collected during a certain set of experiments, Pa; The average value of the pressure difference signal collected during a group of experiments, Pa.

[0051] Step 1.2: Based on step 1.1, slowly open the valve of the liquid phase supply device and adjust the liquid phase flow rate to a fixed value M. l1 During the adjustment process, it is necessary to keep the gas phase flow rate at Q g1 After the flow rate stabilizes for a period of time, the data acquisition unit records the average pressure difference signal before and after the nozzle. Pressure difference signal fluctuation standard deviation (σ ΔP ) g+l1,1 And the temperature drop ΔTg+l1,1 .

[0052] Step 1.3: After the collection in step 1.2 is completed, continue to slowly adjust the valve of the liquid phase supply device to increase the liquid phase flow rate to M l2 During the adjustment process, it is still necessary to keep the gas phase flow rate at Q g1 After the flow rate stabilizes, record the average pressure difference signal before and after the nozzle Pressure difference signal fluctuation standard deviation (σ ΔP ) g+l1,2 And the temperature drop ΔT g+l1,2 .

[0053] Repeat the above acquisition process, and each subsequent adjustment will increase the liquid phase flow rate by a certain amount until the liquid phase flow rate is adjusted to the maximum value M. ln , record the average value of the pressure difference signal before and after the nozzle Pressure difference signal fluctuation standard deviation (σ ΔP ) g+l1,n And the temperature drop ΔT g+l1,n .

[0054] Step 1.4: Adjust the gas phase flow rate to Q g2 , record the average value of the pressure difference signal before and after the nozzle Pressure difference signal fluctuation standard deviation (σ ΔP ) g2,0 And the temperature drop ΔT g2,0 The valve of the liquid supply device was gradually adjusted to increase the liquid flow rate, and the second set of data was collected.

[0055] Step 1.5: Gradually adjust the gas phase flow rate to the maximum value Q gm , record the average value of the pressure difference signal before and after the nozzle Pressure difference signal fluctuation standard deviation (σ ΔP ) gm,0 And the temperature drop ΔT gm,0 . And gradually adjust the valve of the liquid phase supply device to increase the liquid phase flow until M ln Repeat the above acquisition process and record the average pressure difference signal before and after the nozzle device Pressure difference signal fluctuation standard deviation (σ ΔP ) g+lm,n And the temperature drop ΔT g+lm,n .

[0056] 2. Nozzle upstream pressure and temperature test

[0057] Read the temperature and pressure data of the thermometer and pressure gauge connected to the gas phase supply device for gas phase density calculation.

[0058]

[0059] In formula (3), P is the gas pressure upstream of the nozzle, Pa; M mol is the gas phase molar mass, g / mol; n is the molar number of the gas substance, mol; R is the gas state constant, J / (mol·K); T is the absolute temperature of the gas phase, K.

[0060] 3. Liquid phase density test

[0061] By using the densitometer method, place the densitometer into the liquid to be tested, read the density directly, and test the liquid phase density ρ in the extracted medium. l .

[0062] 4. Change opening adjustment experiment

[0063] The metering model building module is also used to change the opening D value of the nozzle throttling device, restart the above experimental test process, and obtain a fourth data set containing multiple nozzle opening and nozzle flow coefficient data pairs based on the experimental data set of the same size nozzle at different openings. The corresponding relationship between the nozzle flow coefficient and the opening is obtained by fitting, that is, the analytical coupling nozzle flow coefficient C v Value changes with opening curve C v (D), see Figure 2 shown.

[0064] The recommended opening D selections are: 20%, 40%, 60%, 80%, and 100% for research.

[0065] 2. Optimization of sampling frequency of the measurement model establishment module: Preliminary experiments optimize the selection of the best pressure difference signal sampling frequency and sampling time

[0066] 1. Necessity of setting up sampling frequency optimization module

[0067] When throttling occurs, the phase fraction will affect the energy exchange and flow state between the gas and liquid phases, which in turn affects the stability of the differential pressure signal. The differential pressure signal will fluctuate over time. In order to obtain the most stable and reliable differential pressure signal, a preliminary experiment is first conducted to select the optimal frequency and time for collecting the differential pressure signal.

[0068] See also Figure 3 As shown in the figure, it is a schematic diagram of the pressure difference fluctuation over time in the nozzle throttling test. If the acquisition frequency is too high and the acquisition time is too long, the amount of collected data will be too large and the processor will be overloaded. If the acquisition frequency is too low, the most comprehensive pressure difference signal cannot be obtained, and even the fluctuation of the pressure difference signal over time cannot be sensitively captured, resulting in the failure of the collected pressure difference data, or requiring too long an acquisition time series to supplement it. If the acquisition time is too short, the pressure difference signal fluctuation may not even reach a stable state and cannot be used for phase content prediction. Therefore, before the metering experiment begins, it is necessary to compare and select the optimal acquisition frequency and time of the nozzle throttling device through preliminary experiments to find the minimum frequency and time that meet the experimental requirements.

[0069] 2. Method for determining the optimal acquisition frequency and acquisition time

[0070] During the preliminary experiment, adjust the valve and select a set of liquid flow M li and gas phase flow rate Q gi Keep it constant. Gradually increase the frequency and time of pressure difference signal acquisition, and test the standard deviation of pressure difference signal fluctuation σ ΔP , until σ ΔP The value remains stable and no longer changes with the increase of the pressure difference signal acquisition frequency and the extension of the acquisition time. The acquisition frequency and acquisition time corresponding to this point are the optimal acquisition frequency and acquisition time.

[0071] By establishing a module through the metering model, the signal acquisition frequency and acquisition time of the differential pressure transmitter are increased in turn, and the differential pressure signal collected at the current signal acquisition frequency and acquisition time is obtained from the differential pressure transmitter of the oil well multiphase medium production simulation equipment in real time. According to the current differential pressure signal, it is judged whether the change amplitude of the standard deviation of the throttling differential pressure fluctuation before and after the oil nozzle is less than the set amplitude, and the differential pressure fluctuation signal reaches a stable, complete and continuous state; if so, the current signal acquisition frequency and acquisition time are determined as the optimal signal acquisition frequency and acquisition time.

[0072] Preferably, the recommended acquisition time settings for the preliminary experiment are: 10s, 20s, 40s, 70s, 110s, 160s...

[0073] Recommended acquisition frequency settings: 50Hz, 80Hz, 120Hz, 170Hz, 230Hz...

[0074] Recommended acquisition time range: 10 to 160 seconds; acquisition frequency range: 50 to 230 Hz.

[0075] 3. Optimization of sampling frequency and sampling time based on field instruments

[0076] If it meets the needs of the site, query the upper limit of the frequency f of the differential pressure transmitter instrument signal data that can be allowed by the site communication system. max After that, according to the upper frequency limit, the experiment can be carried out according to The frequency is used as the optimal frequency to conduct experiments and select the appropriate sampling time. During the experiment, the sampling time is gradually increased (it is recommended to increase from 10s upwards), and the extracted pressure difference fluctuation signal will become more and more complete and effective. Until the fluctuation signal is stable and the fluctuation standard deviation value meets the minimum time t required for analysis min sequence as the optimal sampling time.

[0077] If the minimum time series exceeds 160s, increase the sampling frequency to Restart the experiment until the lowest time series is tested to be within 160s.

[0078] The laboratory tests the pressure difference signal fluctuation standard deviation σ according to the above standards ( ΔP , until σ ΔP The value remains stable and no longer changes with the increase of pressure difference signal acquisition frequency and the extension of acquisition time). Experiments are carried out to select the best sampling time for field testing.

[0079] The specific plan is as follows:

[0080] Table 1 Optimal signal acquisition frequency and acquisition time determination experiment recommended signal acquisition frequency and acquisition time setting table

[0081]

[0082] 3. Experimental Dataset

[0083] 1. Experimental setup The gas-liquid flow matrix is ​​as follows:

[0084]

[0085] 2. Experimental setup The gas phase mass holdup matrix is ​​as follows:

[0086]

[0087] in:

[0088]

[0089] 3. Experimental test records of hydraulics (differential pressure mean value B1 and fluctuation value data set matrix B2) and thermals (temperature drop value data set matrix B3) are as follows:

[0090]

[0091]

[0092]

[0093] The data storage unit of the metering model building module obtains the above data set matrix and stores it for use in subsequent metering model building of multiphase media.

[0094] In addition, based on the experimental data set of the same size nozzle at different openings, a fourth data set including multiple nozzle opening and nozzle flow coefficient data pairs can be obtained, and the corresponding relationship between the nozzle flow coefficient and the opening can be obtained by fitting.

[0095] It should be noted that the specifications of the oil nozzles used in the experiment are consistent with the specifications of the oil nozzles in the oil wells to which the calculation model established in this embodiment is applicable.

[0096] 4. The metering model establishment module establishes the gas phase mass content calculation model.

[0097] The embodiment of the present invention innovatively integrates the nozzle throttling pressure difference fluctuation standard deviation and temperature drop characteristics to invert and calculate the phase mass content.

[0098] 1. The first functional relationship is established to characterize the relationship between gas mass content and the standard deviation of throttling pressure difference fluctuation.

[0099] When throttling occurs, the phase separation mass content will affect the energy exchange and flow state between the gas and liquid phases, and then affect the stability of the pressure difference signal. The pressure difference signal will fluctuate with time. Therefore, the characteristic value and fluctuation law of the pressure difference signal contain information on the gas-liquid two-phase flow parameters. By analyzing the characteristic value and fluctuation law of the pressure difference signal and establishing a correlation model, the gas phase mass content can be measured online.

[0100] Gas phase holdup x g When it is smaller, the liquid phase flow content is larger and belongs to the continuous phase in the two-phase flow, while the gas phase belongs to the dispersed phase. When the bubbles in the liquid flow pass through the nozzle, the bubbles break into small bubbles, causing pressure difference fluctuations. g The gas phase content gradually increases and becomes the continuous phase of the two-phase flow. The liquid phase will be blown by the airflow and transformed into tiny droplets, which are distributed more evenly in the gas phase. At this time, the pressure difference fluctuation through the nozzle becomes gentle.

[0101] Specifically, based on the experimental data set obtained from the hydraulic and thermodynamic characteristics experiment of the above-mentioned produced medium throttling condition, a first data set containing multiple pairs of throttling pressure difference standard deviation and gas phase mass content data is obtained, and a first functional relationship for characterizing the relationship between the gas phase mass content and the throttling pressure difference standard deviation is obtained by fitting.

[0102] Typically, a pressure difference signal fluctuation standard deviation σ ΔP and gas mass fraction x g For the corresponding relationship, see Figure 4 shown.

[0103] Therefore, based on the matrices A2 and B2 in the throttling experiment results, the standard deviation σ of the pressure difference signal fluctuation when reaching a stable state can be established. ΔP and gas mass fraction x g The functional relationship of .

[0104] σ ΔP =H(x g ) (10)

[0105] The standard deviation of pressure difference fluctuation σ ΔP Inverse calculation of gas phase mass fraction x g , the functional relationship is established as above g ) is the inverse function of:

[0106] x g =H -1 (σ ΔP ) (11)

[0107] 2. Establish a second functional relationship to characterize the relationship between gas mass content and temperature drop amplitude.

[0108] The relationship between the temperature drop characteristics and the phase separation fraction of the gas and liquid phases when throttling occurs is very complex. After the gas phase component in the produced liquid passes through the nozzle, the Joule-Thomson effect will cause a temperature drop. The higher the gas mass fraction, the more significant the Joule-Thomson effect, and the greater the temperature drop after the nozzle throttling.

[0109] Based on the above experimental data set, a second data set including multiple pairs of temperature drop amplitude and gas mass content is obtained, and a second functional relationship for characterizing the relationship between gas mass content and temperature drop amplitude is obtained by fitting.

[0110] Typically, the temperature drop amplitude ΔT of a nozzle throttling is related to the gas mass fraction x g For the corresponding relationship, see Figure 5 shown.

[0111] Therefore, based on the matrices A2 and B3 in the throttling experiment results in step 1, a functional relationship model between the temperature drop characteristics and the gas phase mass fraction can be established:

[0112] ΔT=h(x g ) (12)

[0113] Where ΔT is the nozzle throttling temperature drop value collected during a certain set of experiments, ℃.

[0114] The gas phase fraction x can be calculated by the nozzle throttling temperature drop ΔT g , the functional relationship is established as above g ) is the inverse function of:

[0115] x g =h -1 (ΔT) (13)

[0116] 3. Based on the first functional relationship and the second functional relationship, a gas phase mass content calculation model is established.

[0117] Typically, when the gas mass holdup is low, the fluctuation characteristics of the throttling pressure difference are more obvious, and the standard deviation of the fluctuation σ ΔP The value is large and σ ΔPValue for gas mass fraction x g The change of x is more sensitive. g The changes are significant.

[0118] When the gas mass fraction is high, the throttling temperature drop characteristics are more obvious, and the throttling temperature drop ΔT value is larger, and the ΔT value has a significant effect on the gas mass fraction x. g The change of x is more sensitive. g The changes are significant.

[0119] Therefore, it is recommended to comprehensively consider the hydraulic and thermal characteristics of the nozzle throttling, assign different weights to the inverse function relationship of the nozzle throttling pressure difference fluctuation and temperature drop characteristics to calculate the gas mass holdup according to the gas mass holdup, and inversely calculate the phase holdup.

[0120] x g =mH -1 (σ ΔP )+nh -1 (ΔT) (14)

[0121] When the gas mass holdup is low, H -1 (σ ΔP ) has a higher weight m than h -1 The weight n value of (ΔT) is lower than the weight n value when the gas mass content is high. The recommended values ​​of m and n are shown in Table 2:

[0122] Table 2 Recommended weights m and n for inverse function relationship of inverse calculation of gas mass holdup by comprehensive consideration of the hydraulic and thermal characteristics of nozzle throttling

[0123] Gas phase mass content range Recommended m weight value Recommended n weight value [0，25％) 0.8 0.2 [25％，50％) 0.6 0.4 [50％，75％) 0.4 0.6 [75％，100％] 0.2 0.8

[0124] In some embodiments, the first functional relationship is:

[0125]

[0126] The second functional relationship is:

[0127]

[0128] In formula (15) and formula (16), x g is the gas phase mass fraction; σ ΔP is the standard deviation of the throttling pressure difference, ΔT is the temperature drop amplitude, α, β, γ, p and q are all fitting parameters obtained by fitting.

[0129] The established gas phase mass holdup calculation model is:

[0130]

[0131] In formula (17), m is the first weight, n is the second weight, and m+n=1.

[0132] 5. The metering model building module establishes the metering model of the total mass flow rate and phase mass flow rate of multiphase produced medium in oil wells based on the Lockheed Martin phase flow pressure drop method.

[0133] Based on the experimental data set, the Lockhart-Martinelli parameter (Lockhart parameter X LM ) The multiphase flow pressure drop model expression is transformed and solved to obtain the full liquid phase medium conversion coefficient expression. The gas and liquid are considered as full liquid phases with the same mass flow rate. The total mass flow rate of the multiphase medium is calculated according to the full liquid phase medium conversion coefficient. The calculation model of the total mass flow rate of the multiphase medium is established through the following steps 1-3.

[0134] 1. According to the experimental data set, determine the conversion factor λ used to characterize the gas phase g With Loma parameter X LM The split-phase flow pressure drop model based on the relationship between them.

[0135] The split-phase flow pressure drop model is based on the theory that the gas and liquid phases pass through the nozzle separately. It is assumed that the gas-liquid mixture flows through the nozzle completely separately and has the same outflow coefficient in the same nozzle.

[0136] (1) Determine the Lockhart-Martinelli parameter X LM .

[0137] X LM It is a dimensionless number and is often used to summarize and organize data. LM It is determined by the following formula (18). In formula (18), the gas phase density ρ g Determined by formula (3).

[0138]

[0139] In formula (18), X LM is the Loma parameter, dimensionless; The mass flow rate is M l The average pressure difference generated when the liquid phase passes through the nozzle alone, Pa; The mass flow rate is M g The average pressure difference generated when the gas phase passes through the nozzle alone, Pa; Δl is the pipeline length, m; M l is the mass flow rate of liquid phase through the nozzle, kg / s; M g is the gas mass flow rate through the nozzle, kg / s; ρ l is the liquid density, kg / m 3 ρ g is the gas phase density, kg / m 3.

[0140] Furthermore, the liquid mass flow rate and gas mass flow rate (M g or Q g (represented) is obtained through the above matrix A1; the density of the liquid phase in the produced medium can be tested by placing the density meter into the liquid to be tested and directly reading the density; the gas phase density can be calculated using formula (3) based on the gas pressure and temperature upstream of the nozzle.

[0141] (2) Determine the gas phase conversion coefficient λ g .

[0142] Let the mass flow rate be M g+l The average pressure drop of the gas-liquid two-phase flow flowing through the Δl pipe section is related to the mass flow rate M g The square root of the ratio of the average pressure drop of the gas phase passing through the Δl long pipe section is calculated, and the result is defined as the gas phase conversion coefficient, which is expressed by the dimensionless number λ g express.

[0143] M g+l =M g +M l (19)

[0144]

[0145]

[0146] Where M g+l is the gas-liquid two-phase mass flow rate through the nozzle, kg / s; λ g is the gas phase conversion coefficient, dimensionless; The mass flow rate is M g+l The average pressure difference generated when the gas-liquid two phases pass through the oil nozzle, Pa.

[0147] (3) Determine the applicable expression of the phase separation flow pressure drop model.

[0148] The gas phase conversion coefficient λ obtained by converting the experimental pressure difference g With Loma parameter X LM The changing relationship is plotted, and based on the trend of the graph, an applicable pressure drop model is selected from the existing phase flow pressure drop models.

[0149] The model parameters are determined by data regression. Generally, the applicability of the phase separation flow pressure drop model expression is shown in the following functional relationship:

[0150] λ g =f(X LM ) (twenty two)

[0151]

[0152]

[0153] 2. Based on the phase flow pressure drop model, the conversion coefficient expression of the full liquid phase medium is established, that is, the ternary function expression of gas phase mass content, liquid phase density and gas phase density.

[0154] (1) Assume that the mass flow rate is M g+l The average pressure difference generated when the liquid phase passes through the nozzle is According to the single-phase fluid flow metering formula, With M g+l , With M l , With M g The relationships between them are shown in formulas (25) to (27):

[0155]

[0156]

[0157]

[0158] In the formula, The mass flow rate is M g+l The average pressure difference generated when the liquid phase passes through the nozzle, Pa; ξ is the throttling ratio, that is, the ratio of the cross-sectional diameter of the nozzle throat to the cross-sectional diameter of the pipe, dimensionless; C is the flow coefficient, dimensionless; A is the cross-sectional area of ​​the nozzle throat, m 2 ; ε is the dimensionless expansion coefficient of the measured medium, ε<1 for compressible fluid, ε=1 for incompressible fluid.

[0159] (2)M g 、M l and M g+l The relationship between them is expressed in terms of gas phase mass fraction x g Establish:

[0160] M g =M g+l x g (28)

[0161] M l =M g+l (1-x g ) (29)

[0162] (3) Let the mass flow rate be M g+l The average pressure drop of the gas-liquid two-phase flow through the Δl pipe section is equal to the pressure drop of the gas-liquid two-phase flow with the same mass flow rate M g+lThe square root of the ratio of the average pressure drop of the liquid phase passing through the Δl long pipe section is calculated, and the result is defined as the full liquid phase medium conversion coefficient, expressed as the dimensionless number λ l-Full express.

[0163] Multiply both sides of formula (23) by The total liquid phase medium conversion coefficient λ can be obtained l-Full for and The binary function of As shown in formula (30).

[0164]

[0165] In the formula, λ l-Full is the conversion factor of the full liquid medium, dimensionless.

[0166] (4) Based on the phase flow pressure drop model, the ternary function of gas mass fraction, liquid phase density and gas phase density is obtained:

[0167] Substitute equations (25) to (29) into the full liquid phase medium conversion coefficient λ l-Full The function formula (30) is further transformed and simplified to analyze the final full liquid phase medium conversion coefficient expression, which is a three-variable function of gas mass fraction, liquid density, and gas density. Let the function form be F(x g ,ρ l ,ρ g ), see formula (31) for details.

[0168]

[0169] 3. Based on the conversion coefficient expression of the full liquid phase medium, a calculation model for the total mass flow of multiphase medium is established.

[0170] (1) Assuming that the gas-liquid two-phase flow is uniformly mixed, there is no slip between the phases and the two phases have the same velocity, the mixture density is ρ m , the flow parameters of the two-phase flow are taken as pseudo-single-phase fluid. The pressure difference is the average value of the actual pressure difference when the two-phase nozzle is used for throttling. Calculate the total mass flow rate:

[0171]

[0172] In the formula, ρ m is the density of the mixed fluid upstream of the nozzle before throttling under working conditions, kg / m 3 .

[0173] Now consider the fluid as a full liquid phase and assume that the total mass flow rate is M g+l The pressure difference generated when the full liquid phase nozzle throttling occurs is The total mass flow rate of the entire liquid phase can be expressed as follows:

[0174]

[0175] (2) The gas and liquid are equal in mass flow rate M. g+l The density of the liquid phase is ρ l The pressure difference is the average value of the actual pressure difference when two-phase flow flows through the nozzle throttling. Calculate the mass flow rate M g+l , the full liquid phase medium conversion factor λ l-Full After conversion calculation, the total mass flow rate of multiphase medium is:

[0176]

[0177] Substituting the mass gas phase holdup method in formula (14) into formula (34), the total mass flow rate of the multiphase medium can be calculated:

[0178]

[0179] 4. Establish a mass flow measurement model for oil, gas and water phases in multiphase production media of oil wells.

[0180] (1) Based on the total mass flow rate and gas phase mass fraction calculation model, the gas phase mass flow rate M can be established g and liquid mass flow rate M l Computational model:

[0181]

[0182]

[0183] (2) According to the moisture content test result x of the moisture analyzer w , the mass flow rate M of the water phase in the liquid phase can be established w and oil phase mass flow rate M o :

[0184]

[0185]

[0186] Where M w is the mass flow rate of water phase, kg / s; M o is the oil phase mass flow rate, kg / s; x w is the mass moisture content.

[0187] 6. The metering model building module builds the total mass flow rate and phase mass flow rate calculation model of the oil well produced medium based on the multiphase fluid throttling linear function.

[0188] The metering model establishment module is specifically used to obtain a third data set including multiple throttling pressure difference, gas phase mass content and total mass flow data groups based on the experimental data set; the linear function between the ratio of the arithmetic square root of the throttling pressure difference before and after the nozzle device and the total mass flow of the multiphase produced medium and the gas phase mass content of the multiphase produced medium is obtained by fitting, and the total mass flow linear function is established. The specific establishment process is as follows:

[0189] 1. Derive and establish the linear function relationship of total mass flow rate.

[0190] Assume that the mass flow rate is M g+l The average pressure difference generated when the liquid phase passes through the nozzle is but The square root of the ratio of the gas mass fraction x g The following relationship is met:

[0191]

[0192] In the formula, The mass flow rate is M g+l The average pressure drop of the gas-liquid two-phase flow through the nozzle throttling, Pa; The mass flow rate is M g+l The average pressure difference generated when the single-phase liquid passes through the nozzle, Pa; ρ l Liquid density. The density value is read by placing the densitometer into the liquid to be tested, kg / m 3 ; ψ is the correction coefficient, which is related to the gas-liquid density ratio and is dimensionless.

[0193] According to the single-phase fluid flow metering formula, With M g+l The relationship between them conforms to the following formula:

[0194]

[0195] Where ξ is the throttling ratio, which is the ratio of the cross-sectional diameter of the nozzle throat to the cross-sectional diameter of the pipe, dimensionless; C v is the flow coefficient, dimensionless; A is the cross-sectional area of ​​the nozzle throat, m 2 ; ε is the dimensionless expansion coefficient of the measured medium, ε<1 for compressible fluid, ε=1 for incompressible fluid.

[0196] Calculate formula (40) Substituting into formula (41), we can get:

[0197]

[0198] It can be seen that the ratio of the mean square root of the throttling pressure difference to the total mass flow rate is and gas phase mass fraction x gThere is the above linear relationship between them.

[0199] 2. Based on the experimental data set, linear fitting is used to establish the total mass flow measurement function.

[0200] Specifically establish the total mass flow rate M g+l In the process of metering function, based on the differential pressure mean matrix B1, gas-liquid total mass flow matrix A3 and gas phase mass content matrix A2 of the experimental data set obtained in step 1, a third data set including multiple throttling pressure differences, gas phase mass content and total mass flow data sets is obtained; the data fitting method is adopted and the least squares method is used to obtain

[0201] and x g The linear relationship between them.

[0202]

[0203] Where M and N are dimensionless parameters obtained by fitting the experimental data set.

[0204] According to experiments, the recommended M value range is generally between 0.76 and 1.99; the recommended N value range is between 6.11 and 10.73. Figure 6 As shown, it is a schematic diagram of the relationship between the ratio of the arithmetic square root of the nozzle throttling pressure difference to the total mass flow rate and the gas phase mass content. It can be seen that the two are in a good linear relationship.

[0205] The total mass flow rate M g+l The measurement function is:

[0206]

[0207] Furthermore, the flow coefficient of the nozzle device can be determined according to the opening value of the nozzle device by using the corresponding relationship between the nozzle flow coefficient and the opening; and the linear function of the total mass flow can be corrected according to the flow coefficient of the nozzle device:

[0208]

[0209] Substituting the mass gas phase holdup function in formula (17) into formula (45), the total mass flow rate of the multiphase medium can be calculated:

[0210]

[0211] 3. Establish a phase-separated mass flow measurement model for multiphase produced media in oil wells based on the total mass flow linear function measurement model

[0212] (1) Based on the total mass flow linear metering function and the gas phase mass fraction calculation model, the gas phase mass flow rate M can be established g and liquid mass flow rate Ml Computational model:

[0213]

[0214]

[0215] (2) According to the moisture content test result x of the moisture analyzer w , the mass flow rate M of the water phase in the liquid phase can be established w and oil phase mass flow rate M o :

[0216]

[0217]

[0218] Where M w is the mass flow rate of water phase, kg / s; M o is the oil phase mass flow rate, kg / s; x w is the mass moisture content.

[0219] VII. Modification of the established metering model for multiphase oil well production media by the metering model building module

[0220] The phase flow values ​​calculated by the metering model are combined with the actual flow values ​​input by the input data set A1 to further modify the model to obtain a higher accuracy value.

[0221] The metering model establishment system for multiphase produced medium in oil wells provided by the embodiment of the present invention includes a multiphase produced medium in oil wells simulation device, which is used to simulate the throttling pressure difference signal and temperature drop amplitude before and after the oil nozzle when the gas phase and liquid phase of different flow combinations are mixed and pass through the oil nozzle, so as to obtain an experimental data set; the metering model establishment module of the system is used to establish a gas phase mass content calculation model and a total mass flow calculation model for the multiphase produced medium in oil wells based on the experimental data set. The model established by the system can accurately and conveniently meter the multiphase produced medium in oil wells on the basis of obtaining the average value, standard deviation and temperature drop amplitude of the throttling pressure difference before and after the oil nozzle of the oil well; and the ground process flow is simple, the metering cost is low, and the measurement accuracy is high, and it is still applicable to the multiphase produced medium in oil wells with a high gas-liquid ratio.

[0222] Embodiment 2

[0223] The embodiment of the present invention provides a corrected model of an oil well metering system, which can be widely used.

[0224] 1. Optimize and select the best pressure difference signal sampling frequency and sampling time

[0225] For a self-flowing oil well in an oil field, the wellhead is equipped with an oil nozzle and a pressure and temperature measuring device. The on-site ZigBee network transmission communication system can transmit the wellhead collected data to the data processing server. The upper limit of the permissible instrument signal data transmission and collection frequency is f max The frequency is 300Hz. The metering model of multiphase produced medium in oil wells is used to establish the system and carry out metering experiments.

[0226] Using the sampling frequency time series optimization module in the experimental system, preliminary test optimization was carried out to select the optimal pressure difference signal sampling frequency and sampling time. The pressure difference signal sampling frequency is The sampling time is 110s, which is applicable to the field. At this time, the pressure difference fluctuation signal extracted by the metering system is complete, effective and stable, and the acquisition time is within the required minimum time series range. The pressure difference fluctuation characteristics no longer change with the increase of the pressure difference signal acquisition frequency and the extension of the acquisition time.

[0227] 2. Establish a gas phase mass holdup calculation model

[0228] The internal data sets stored in the experimental data set matrix are analyzed, and the gas phase mass fraction function is used to establish the module. The first functional relationship is determined by the characteristic value of the pressure difference fluctuation:

[0229]

[0230] Through the nozzle throttling temperature drop value, the second functional relationship for calculating the gas mass fraction based on the temperature drop characteristics is established:

[0231]

[0232] By integrating the nozzle throttling pressure difference fluctuation and temperature drop characteristics, a gas phase mass holdup calculation model is established for gas phase mass holdup calculation:

[0233]

[0234] 3. Analytically calculate the total mass flow rate including the opening setting.

[0235] The opening D is selected in sequence: 20%, 40%, 60%, 80%, 100% for measurement test, and the C under different openings is obtained. v Value, fitting C v The relationship between the opening D and the opening C v (D) The expression is:

[0236] C v (D) = 3.17e 4.5D+1.62 +5.36 (54)

[0237] 4. Establish a linear metering function for the total mass flow rate of multiphase produced media

[0238] For example, through experimental fitting, a commonly used M value in the linear calculation function of the total mass flow of multiphase produced medium is 1.39, which is between the aforementioned recommended M value range of 0.76 and 1.99; a commonly used N value is 9.14, which is between the aforementioned recommended N value range of 6.11 and 10.73. Then the total mass flow linear function is:

[0239]

[0240] The gas phase mass holdup calculation model (33) and C v Substituting the relationship expression (54) with the opening D into (55) we get the total mass flow expression:

[0241]

[0242] Simplified to:

[0243]

[0244] 5. Establish a measurement model for oil, gas and water phase flow values

[0245] According to the total mass flow rate and gas phase mass fraction calculation model, the gas phase mass flow rate M can be established g and liquid mass flow rate M l Computational model:

[0246]

[0247]

[0248] According to the moisture content test result of the moisture analyzer x w , the mass flow rate M of the water phase in the liquid phase can be established w and oil phase mass flow rate M o :

[0249]

[0250]

[0251] In summary, the average throttling pressure difference of the known nozzle Throttling pressure difference fluctuation standard deviation σ ΔP , throttling temperature drop ΔT, test moisture content x w , and the nozzle opening D, are substituted into the above formulas (38) to (41), and the three-phase metering of oil, gas and water can be achieved.

[0252] 6. Measuring accuracy effect

[0253] Using formulas (58)-(61), the three-phase flow rates of oil, gas and water of the well were measured and compared with the actual data of on-site separation measurement. The average daily production of the single well was calculated, as shown in Table 3. It can be seen that the average deviation is within 4%, and the measurement effect meets the requirements.

[0254] Table 3 Comparison of metering effects

[0255]

[0256] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a multiphase metering method for oil well production, comprising:

[0257] According to the standard deviation of the throttling pressure difference fluctuation and the temperature drop amplitude before and after the oil nozzle set in the target oil well, the gas mass content calculation model is used to determine the gas mass content of the multiphase medium produced from the oil well;

[0258] According to the average value of the throttling pressure difference before and after the nozzle and the determined gas phase mass content, the total mass flow rate of the multiphase medium is obtained by using the total mass flow calculation model. The gas phase mass content calculation model and the total mass flow calculation model are established through the above-mentioned oil well production multiphase metering modeling system.

[0259] The size of the nozzle in the target oil well is consistent with the size of the nozzle selected when the multiphase metering modeling system of the oil well produced material establishes the metering model.

[0260] In some embodiments, after determining the total mass flow rate of the multiphase produced medium, the mass flow rate of the liquid phase medium and / or the mass flow rate of the gas phase medium in the multiphase produced medium can also be obtained based on the total mass flow rate of the multiphase produced medium and the gas phase mass content.

[0261] It is also possible to obtain the mass flow rate of water phase produced liquid and / or the mass flow rate of oil phase produced liquid in the multiphase produced medium according to the water content of the multiphase produced medium and the mass flow rate of the liquid phase medium. The water content of the multiphase produced medium is measured by a water content analyzer.

[0262] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned multiphase metering method for oil well production is implemented.

[0263] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a server, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-mentioned multiphase metering method for oil well production when executing the program.

[0264] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0265] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0266] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that an embodiment of the claimed subject matter requires more features than those set forth in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0267] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0268] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0269] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0270] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to represent "non-exclusive or". The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

Claims

1. A multiphase measurement modeling system for oil well production, characterized in that: Including oil well multiphase medium production simulation equipment and measurement model establishment module; The oil well multiphase medium extraction simulation equipment includes a liquid phase supply device, a gas phase supply device, a mixer and a nozzle connection device, which is used to measure the throttling pressure difference signal and temperature drop amplitude before and after the nozzle when the gas phase and liquid phase of different flow combinations are mixed and pass through the selected nozzle to obtain an experimental data set; The metering model establishment module is used to establish a gas phase mass content calculation model and a total mass flow calculation model for the multiphase produced medium of the oil well based on the experimental data set. The gas phase mass content calculation model is used to characterize the relationship between the standard deviation of the throttling pressure difference fluctuation before and after the nozzle, the temperature drop amplitude and the gas phase mass content of the multiphase medium; the total mass flow calculation model is a linear function relationship between the ratio of the arithmetic square root of the mean value of the throttling pressure difference before and after the nozzle device and the total mass flow of the multiphase produced medium and the gas phase mass content of the multiphase produced medium.

2. The system according to claim 1, characterized in that The measurement model establishment module is specifically used for: Based on the experimental data set, a first data set including a plurality of data pairs of throttling pressure difference fluctuation standard deviation and gas phase mass holdup is obtained, and a first functional relationship for characterizing the relationship between the gas phase mass holdup and the throttling pressure difference fluctuation standard deviation is obtained by fitting; Based on the experimental data set, a second data set including a plurality of temperature drop amplitude and gas phase mass content data pairs is obtained, and a second functional relationship for characterizing the relationship between the gas phase mass content and the temperature drop amplitude is obtained by fitting; Based on the first functional relationship and the second relationship, a gas phase mass content calculation model is established.

3. The system according to claim 2, characterized in that The first functional relationship is: The second functional relationship is: In formula (1) and formula (2), x g is the gas phase mass fraction; σ ΔP is the standard deviation of throttling pressure difference fluctuation, ΔT is the temperature drop amplitude, α, β, γ, p and q are fitting parameters obtained by fitting.

4. The system according to claim 3, characterized in that The gas phase mass holdup calculation model is: In formula (3), m is the first weight, n is the second weight, and m+n=1.

5. The system according to claim 1, characterized in that The measurement model establishment module is specifically used for: Based on the experimental data set, a third data set including a plurality of throttling pressure difference, gas phase mass fraction and total mass flow rate data sets is obtained; The linear function between the ratio of the arithmetic square root of the throttling pressure difference before and after the nozzle device and the total mass flow rate of the multiphase produced medium and the gas mass content of the multiphase produced medium is obtained by fitting, and the total mass flow rate linear function is established: In formula (4), M g+l is the total mass flow rate of multiphase produced medium, ΔP g+l The mass flow rate is M g+l When the gas-liquid two-phase medium flows through the nozzle device, the average throttling pressure difference before and after the nozzle device, x g is the gas mass content of the multiphase produced medium, M and N are fitting parameters obtained by fitting.

6. The system according to claim 5, characterized in that The measurement model building module is also used for: According to the opening value of the nozzle device, the flow coefficient of the nozzle device is determined by using the corresponding relationship between the nozzle flow coefficient and the opening; According to the flow coefficient of the nozzle device, the total mass flow linear function is corrected: In formula (5), C v is the flow coefficient of the nozzle device.

7. The system according to claim 6, characterized in that The metering model building module is also used to establish the corresponding relationship between the nozzle flow coefficient and the opening in the following manner: Based on the experimental data set of the nozzle of the same size at different openings, a fourth data set including multiple data pairs of nozzle openings and nozzle flow coefficients is obtained, and the corresponding relationship between the nozzle flow coefficient and the opening is obtained by fitting.

8. The system according to claim 1, characterized in that The nozzle connection device is used to connect the selected nozzle, the upstream first node and the downstream second node of the nozzle connection device are respectively connected to the two ends of the differential pressure transmitter, and the upstream third node and the downstream fourth node of the nozzle connection device are respectively connected to the two ends of the differential temperature transmitter; The upstream end of the mixer is connected to the liquid phase supply device and the gas phase supply device, and the downstream end is connected to the upstream end of the nozzle connection device; The gas phase supply device is connected to a gas phase flow meter, a thermometer and a pressure gauge, and the liquid phase supply device is connected to a liquid phase flow meter.

9. The system according to claim 8, characterized in that The oil well multiphase medium production simulation device also includes a separator; The downstream end of the oil nozzle connecting device is connected to the inlet of the separator; The gas phase outlet of the separator is connected to the upstream end of the gas phase supply device, and the liquid phase outlet of the separator is connected to the upstream end of the liquid phase supply device.

10. The system according to claim 9, characterized in that The measurement model building module is also used for: The signal acquisition frequency and acquisition time of the pressure differential transmitter are increased sequentially, and the pressure differential signal collected at the current signal acquisition frequency and acquisition time is obtained from the pressure differential transmitter of the oil well multiphase medium production simulation device in real time. It is determined based on the current pressure differential signal whether the change amplitude of the standard deviation of the throttling pressure differential fluctuation before and after the oil nozzle is less than the set amplitude; if so, the current signal acquisition frequency and acquisition time are determined as the optimal signal acquisition frequency and acquisition time.

11. A multiphase metering method for oil well production, characterized in that: include: According to the standard deviation of the throttling pressure difference fluctuation and the temperature drop amplitude before and after the oil nozzle set in the target oil well, the gas mass content calculation model is used to determine the gas mass content of the multiphase medium produced from the oil well; According to the average value of the throttling pressure difference before and after the nozzle and the determined gas phase mass content, the total mass flow rate of the multiphase medium is obtained by using the total mass flow calculation model. The gas phase mass content calculation model and the total mass flow calculation model are both established by the multiphase metering modeling system for oil well production as described in any one of claims 1 to 10.

12. The method according to claim 11, characterized in that Also includes: The mass flow rate of the liquid phase medium and / or the mass flow rate of the gas phase medium in the multiphase medium is obtained according to the total mass flow rate of the multiphase medium and the gas phase mass content.

13. The method according to claim 12, characterized in that Also includes: The mass flow rate of the water phase produced fluid and / or the mass flow rate of the oil phase produced fluid in the multiphase medium is obtained according to the water content of the multiphase medium and the mass flow rate of the liquid phase medium.

14. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by the processor, the multiphase metering method for oil well production products according to any one of claims 11 to 13 is implemented.

15. A server, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the multiphase metering method for oil well production according to any one of claims 11 to 13 is implemented.

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