A gas overflow control type oil well online metering device, method, equipment and medium

Abstract

The present invention provides an overflow-controlled oil well online metering device, method, equipment, and medium. The device measures flow rate by combining a coaxial line phase-method water-cut meter with a related flowmeter. When fluid enters the device, it flows sequentially through two coaxial line phase-method water-cut meters, generating two water-cut signals. The changes in these two signals are similar, and there is a certain time delay. By calculating the time delay of the two water-cut signals and combining it with the pipeline dimensions and the spacing between the two water-cut meters, the flow rate can be calculated. This achieves integrated online real-time measurement of water cut and flow rate, improving measurement reliability. Furthermore, the present invention achieves gas-liquid separation by adjusting the overflow control valve, reducing the impact of gas on measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of crude oil production, and in particular to an on-line metering device, method, equipment and medium for a gas overflow control oil well. Background Art

[0002] Measuring oil well production is a crucial task in oilfield production management. Accurate and timely measurement of well production plays a crucial role in understanding reservoir conditions and formulating production plans. Oil well production measurement is categorized into metering in a metering room and wellhead measurement, based on the location of the metering equipment. Metering in a metering room primarily measures oil, water, and gas production, while water cut is still determined by sampling and testing at the wellhead. Domestic oilfields still rely on traditional metering in a metering room, which accounts for over 90% of all wells. Common methods for measuring oil in a metering room are gas measurement using a separator orifice plate and a tipping bucket orifice plate. Separator oil measurement relies on the principle of liquid level equilibrium and utilizes a fixed container method. When the liquid level in the container rises to a certain height, the oil is measured using a glass tube or a tipping plate. During periods of high water cut, especially extremely high water cut, draining wells with low gas-to-liquid ratios after measurement is extremely difficult, significantly complicating metering operations. A tipping bucket oil metering system primarily consists of an oil meter and a counter. When one bucket is full, it is tipped over to drain the oil, and the other bucket is filled. This cycle is repeated to accumulate oil. This technology requires simple equipment and low investment, but the use of intermittent oil metering to convert production leads to a system error of approximately 10%-20%. Wellhead metering typically uses volumetric flowmeters, gravimetric flowmeters, and mass flowmeters. Software-based oil metering, such as dynamometer charts, is also available. This method, based on the relationship between the operating conditions of a deep-well pump and the changes in well fluid production, establishes a three-dimensional mathematical model of the sucker rod, tubing, and fluid column. By calculating the effective stroke of the plunger and combining it with reservoir properties and production data, the well production is determined. However, this method's measurement accuracy is significantly affected by factors such as the calculation model and wax deposition in the wellbore.

[0003] The above analysis reveals that the current oil well metering methods used in oil fields each have their own advantages and disadvantages, and none of them can achieve convenient, fast, direct, and accurate online measurement of wellhead fluid production under various operating conditions. Furthermore, current oil well metering methods require sampling and testing to measure water content, which is time-consuming and subject to significant errors from manual sampling. Crude oil water content is also a critical parameter that reflects the specific conditions of an oil well. Therefore, there is a need to improve the automation level and measurement accuracy of crude oil water content measurement.

[0004] The coaxial line phase-based water-cut meter is a well logging instrument for measuring the water content of crude oil. It can dynamically and continuously measure the water content from 0 to 100% with consistent and high accuracy. Its operating principle primarily uses a coaxial line as a sensor, with the instrument housing as an outer conductor. As the oil-water mixture flows between the inner and outer conductors of the coaxial line sensor, it acts as a carrier for electromagnetic waves. Mixtures with varying oil-water ratios cause the phase of these electromagnetic waves to shift. By measuring the phase characteristics of the electromagnetic wave propagating through the sensor, the dielectric properties of the oil-water mixture are determined. Using a water-cut measurement model, the water content of the oil-water mixture can be determined. This instrument has been tested in numerous simulated wells and has proven its stable performance, high sensitivity, and strong resolution, leading to its widespread use in oil well sites.

[0005] With technological advancements, oilfields are increasingly in need of powerful, accurate oil well metering equipment to improve production efficiency and oilfield management. Applying coaxial line phase-method water cut meters to oil well metering equipment can better address current problems in oil well metering. Summary of the Invention

[0006] In response to the technical problems mentioned in the above background technology, a gas overflow-controlled oil well online metering device is provided. The flow rate is measured by forming a related flow meter with a coaxial line phase method water cut meter. When the fluid enters the device, it will flow through two coaxial line phase method water cut meters in succession, generating two water cut signals. The changes in these two signals are similar and there is a certain time delay. By calculating the time delay value of the two water cut signals, combined with the size of the pipeline and the distance between the two water cut meters, the flow rate can be calculated, thereby realizing integrated online real-time measurement of water cut and flow rate, and improving measurement reliability. At the same time, the present invention achieves gas-liquid separation by adjusting the gas overflow control valve, reducing the impact of gas on measurement.

[0007] The technical means adopted in the present invention are as follows:

[0008] A gas overflow control type oil well online metering device includes: a gas-liquid separation unit and a flow-water content measurement unit; the gas-liquid separation unit performs gas-liquid separation via a multiphase flow buffer chamber and a gas overflow control valve; the flow-water content measurement unit includes: an upstream coaxial line phase method water content meter and a downstream coaxial line phase method water content meter; the coaxial line phase method water content meter directly measures the water content of the oil well output fluid; the online metering device includes the combined upstream coaxial line phase method water content meter and the downstream coaxial line phase method water content meter.

[0009] Furthermore, the device comprises: a device liquid inlet, an upstream pipeline, a downstream pipeline connected to the upstream pipeline and having the same structure as the upstream pipeline, and a device liquid outlet; the upstream pipeline comprises: an upstream oil-water-gas multiphase flow buffer chamber, an upstream flow-water content measurement chamber, and an upstream confluence chamber; the upstream oil-water-gas multiphase flow buffer chamber and the upstream confluence chamber are separated by an upstream baffle;

[0010] An upstream overflow control valve is also provided at the top of the upstream oil-water-gas multiphase flow buffer chamber; the upstream baffle is coaxially arranged with the upstream overflow control valve, and an opening is provided at the center of the upstream baffle; the upstream coaxial line phase method water content meter passes horizontally through the central opening provided on the upstream baffle; the upstream flow-water content measurement chamber is provided inside the upstream coaxial line phase method water content meter; the upstream flow-water content measurement chamber of the upstream coaxial line phase method water content meter is provided with a liquid inlet; the upstream flow-water content measurement chamber is also provided with an upstream flow-water content measurement chamber liquid outlet, and the upstream flow-water content measurement chamber liquid outlet is provided in the upstream converging chamber; the upstream converging chamber is connected to the downstream pipeline through a connecting pipe; the metering device also has an upstream inclined baffle provided in the upstream oil-water-gas multiphase flow buffer chamber and at the liquid inlet of the device.

[0011] Furthermore, the upstream coaxial line phase method moisture meter is fixed to the tail end of the upstream pipeline through a flange. At the same time, a spring passes through the interior of the upstream coaxial line phase method moisture meter, and the spring is compressed to fix the packing to achieve sealing.

[0012] Furthermore, when the upstream air overflow control valve is opened, the gas phase flows from the upstream air overflow control valve into the upstream merging chamber; the liquid phase enters the upstream flow-water content measurement chamber through the liquid inlet of the upstream flow-water content measurement chamber to measure the water content, and the measured liquid phase enters the upstream merging chamber through the liquid outlet of the upstream flow-water content measurement chamber and merges with the gas phase; when the upstream air overflow control valve is closed, the gas phase and the liquid phase enter the upstream flow-water content measurement chamber together, and flow into the upstream merging chamber after being measured by the upstream coaxial line phase method water content meter.

[0013] The present invention also provides an overflow-controlled oil well online metering method, which uses a coaxial line phase method water cut meter to achieve integrated measurement of the water cut and flow rate of the oil well output fluid, including the following steps:

[0014] The fluid to be measured is separated into gas and liquid by a gas-liquid separation unit, and the gas phase is controlled by an overflow control unit to prevent it from entering a flow-water content measurement unit. The liquid phase sequentially enters a plurality of flow-water content measurement units with a certain distance therebetween. The flow-water content measurement units then measure the water content signals of the multiple branches respectively. A data acquisition unit acquires the water content signals of the multiple branches and transmits the acquired signals to a computer unit. Furthermore, a cross-correlation operation of the water content signals of the multiple branches is obtained by a computing unit to obtain a cross-correlation function of the multiple branch signals. The flow information of the oil well produced fluid is obtained based on the cross-correlation function, pipeline information, and the distances between upstream and downstream sensors.

[0015] Furthermore, the overflow control unit controls the fluid channel of the gas phase through the overflow control valve; when the overflow control valve is opened, the gas phase does not pass through the flow-water content measurement unit; when the overflow control valve is closed, the gas phase and the liquid phase enter the flow-water content measurement unit together.

[0016] Furthermore, in the gas-liquid separation unit, gas-liquid separation is performed by gravity; wherein the gas phase is in the upper layer and the liquid phase is in the lower layer.

[0017] Furthermore, the flow-water content measurement unit adopts a coaxial line phase method water content meter to measure the water content, and obtains the water content of the fluid to be measured by detecting the change in the phase of the electromagnetic wave propagating in the coaxial line.

[0018] The present invention also provides a device for online metering of overflow-controlled oil wells, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can: output a start signal to the overflow control unit to open the overflow valve; receive water content signals of multiple branches acquired by a data acquisition unit; perform cross-correlation operations under the control of a first built-in program based on the acquired water content signals of the multiple branches to obtain a cross-correlation function; and obtain flow information of the oil well produced fluid based on the cross-correlation function, pipeline information, and the distance between the upstream and downstream sensors under the control of a second built-in program.

[0019] The present invention also provides a medium for online metering of overflow-controlled oil wells, which stores computer-executable instructions, and is characterized in that the computer-executable instructions are configured to: output a start signal to the overflow control unit to open the overflow valve; receive water content signals of multiple branches acquired by a data acquisition unit; perform cross-correlation operations under the control of a first built-in program based on the acquired water content signals of the multiple branches to obtain a cross-correlation function; and obtain flow information of the oil well produced fluid based on the cross-correlation function, pipeline information, and the distance between the upstream and downstream sensors under the control of a second built-in program.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The present invention measures water cut using a coaxial line phase-method water cut meter, eliminating the need for manual sampling and measurement, reducing water cut measurement errors, and enabling continuous, real-time, and accurate measurement. Furthermore, the coaxial line phase-method water cut meter is used to form a related flow meter, achieving integrated measurement of water cut and flow. The flow signal and the water cut signal are synchronously measured and transmitted, providing a strong guarantee for the synchronous interpretation of dynamically changing flow and water cut. Furthermore, because the coaxial line phase-method water cut meter has no moving parts, the sanding phenomenon encountered when measuring flow by a turbine flowmeter is avoided, thereby improving the success rate and stability of flow measurement. The present invention also controls the gas phase fluid channel through an overflow control valve, thereby addressing the impact of the gas phase on metering in low-yield oil wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 Schematic diagram of the structure of the device of the present invention.

[0024] Figure 2 Schematic diagram of the structure of the overflow control valve of the present invention; wherein (a) is the valve closed state; (b) is the valve open state.

[0025] Figure 3 The figure is a schematic diagram of the structure of an optimized and improved device of the present invention.

[0026] Figure 4 Schematic diagram of the data acquisition unit of the present invention

[0027] Figure 5 Schematic diagram of the measurement principle of the flow meter related to the present invention.

[0028] Figure 6 This is a curve chart of field test data.

[0029] In the figure: 1. Liquid inlet of the device; 2. Upstream inclined baffle; 3. Upstream oil-water-gas multiphase flow buffer chamber; 4. Liquid inlet of upstream flow-water content measurement chamber; 5. Upstream overflow control valve; 6. Upstream baffle; 7. Spring; 8. Upstream flow-water content measurement chamber; 9. Liquid outlet of upstream flow-water content measurement chamber; 10. Upstream confluence chamber; 11. Flange; 12. Upstream coaxial line phase method water content meter; 13. Connecting pipe; 14. Downstream inclined baffle; 15. Downstream oil-water-gas multiphase flow buffer chamber; 16. Downstream flow- Liquid inlet of moisture content measurement chamber; 17. Downstream overflow control valve; 18. Downstream baffle; 19. Spring; 20. Downstream flow-water content measurement chamber; 21. Downstream flow-water content measurement chamber liquid outlet; 22. Downstream confluence chamber; 23. Flange; 24. Downstream coaxial line phase method moisture meter; 25. Device liquid outlet; 26. Overflow control valve body; 27. Overflow control valve spool; 28. Valve handle; 29. ​​Universal overflow control valve; 30. Gas phase fluid channel; 31. Data acquisition card; 32. Computer. DETAILED DESCRIPTION

[0030] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] The present invention provides an overflow-controlled online metering device for oil wells, comprising: a gas-liquid separation unit and a flow-water-cut measurement unit. The gas-liquid separation unit performs gas-liquid separation via a multiphase flow buffer chamber and an overflow control valve; the flow-water-cut measurement unit comprises: an upstream coaxial line phase-method water-cut meter and a downstream coaxial line phase-method water-cut meter; the coaxial line phase-method water-cut meter directly measures the water cut of the oil well's produced fluid; and the online metering device comprises the combined upstream coaxial line phase-method water-cut meter and the downstream coaxial line phase-method water-cut meter. This device can utilize the coaxial line phase-method water-cut meter to achieve integrated measurement of the water cut and flow of the oil well's produced fluid, and can be comprehensively applied to various types of oil wells, thereby improving measurement accuracy and metering range.

[0033] As a preferred embodiment, in this application, a coaxial line phase method water content meter is used as a sensor. This instrument is based on electromagnetic wave theory and uses a coaxial line sensor as a sensitive element for oil and water detection. When the oil-water multiphase flow is inside the sensor, it will become a carrier for the electromagnetic wave to propagate in the coaxial line. The dielectric properties of the multiphase flow are related to the dielectric constant and conductivity of the oil and water phases, that is, they are related to the content of each phase. Since the dielectric constant and conductivity of formation water are much greater than those of oil and gas, the dielectric properties of the multiphase fluid are mainly determined by the water content of the mixed medium. When a multiphase fluid with different dielectric properties flows through the inside of the sensor, the change in the dielectric properties of the multiphase fluid will cause the phase of the electromagnetic wave propagating in the coaxial line to change. Therefore, the water content can be measured by measuring the phase change of the electromagnetic wave propagating in the coaxial line.

[0034] Coaxial line sensors offer several advantages over waveguide sensors. First, according to electromagnetic field theory, electromagnetic waves can only propagate in waveguide sensors in TE or TM modes. In coaxial line sensors, electromagnetic waves can propagate not only in TE and TM modes but also in TEM mode. The TEM mode is the simplest propagation mode, and choosing TEM mode for propagation within the coaxial line facilitates accurate measurement of the phase shift produced by electromagnetic wave propagation. Furthermore, coaxial line sensors operate at a frequency of 75 MHz, while waveguide sensors operate at 300 MHz. High-frequency measurement systems have more stringent requirements for the electromagnetic environment and are susceptible to electromagnetic interference from the surrounding environment. Furthermore, the higher the sensor's operating frequency, the more complex the corresponding circuitry becomes, increasing costs.

[0035] At the same time, the present invention also provides an overflow-controlled oil well online metering method, which realizes integrated measurement of the water content and flow rate of the oil well production fluid through a coaxial line phase method water content meter, including the following steps: the fluid to be measured is passed through a gas-liquid separation unit to realize gas-liquid separation, and the gas phase is controlled not to enter the flow-water content measurement unit through the overflow control unit, and the liquid phase enters multiple flow-water content measurement units with a certain distance in turn, and then the flow-water content measurement units respectively measure the water content signals of multiple branches; the data acquisition unit collects the water content signals of the multiple branches and transmits the collected signals to the computer unit; then, the cross-correlation operation of the water content signals of the multiple branches is obtained through the operation unit to obtain the cross-correlation function of the multiple branch signals; the flow information of the oil well production fluid is obtained according to the cross-correlation function, pipeline information and the distance between the upstream and downstream sensors.

[0036] Example 1

[0037] As an embodiment of the present application, Figure 1 As shown, an overflow control type oil well online metering device, the device includes a device liquid inlet, an upstream pipeline, a downstream pipeline connected to the upstream pipeline and having the same structure as the upstream pipeline, and a device liquid outlet. The upstream pipeline includes an upstream oil-water-gas multiphase flow buffer chamber 3, an upstream overflow control valve 5, an upstream flow-water content measurement chamber 8 and an upstream confluence chamber 10. The upstream oil-water-gas multiphase flow buffer chamber 3 is provided with a device liquid inlet 1 at one end, and an upstream inclined baffle 2 is provided at the device liquid inlet 1. The upstream overflow control valve 5 is provided at the top of the upstream oil-water-gas multiphase flow buffer chamber 3. Inside the upstream oil-water-gas multiphase flow buffer chamber 3, an upstream baffle 6 is provided at the corresponding position of the upstream overflow control valve 5. The center of the upstream baffle 6 is A circular hole is formed. An upstream coaxial line phase-based moisture meter 12 passes horizontally through the central circular hole of the upstream baffle 6. The upstream flow-water-content measurement chamber 8 is located within the upstream coaxial line phase-based moisture meter 12. The upstream flow-water-content measurement chamber's liquid inlet 4 is located within the upstream oil-water-gas multiphase flow buffer chamber 3. The upstream coaxial line phase-based moisture meter 12 is fixed to the tail end of the upstream pipeline via a flange 11. A spring 7 passes through the upstream coaxial line phase-based moisture meter, which compresses the packing to achieve a seal. The upstream confluence chamber 10 is located on the other side of the upstream baffle 6. The upstream flow-water-content measurement chamber's liquid outlet 9 is located within the upstream confluence chamber 10. The upstream confluence chamber 10 is connected to the downstream pipeline via a connecting pipe 13.

[0038] like Figure 2As shown, the overflow control valve comprises an overflow control valve body 26, an overflow control valve core 27, and a valve handle 28. During use, the overflow control valve body 26 must be installed on top of the oil-water-gas multiphase flow buffer chamber and connected to the chamber. A baffle is installed directly below the valve within the oil-water-gas multiphase flow buffer chamber. The baffle has a circular hole in its center, through which a coaxial line phase-based moisture meter is inserted, positioning the meter's inlet within the oil-water-gas multiphase flow buffer chamber. The overflow control valve core 27 is a cylindrical structure that fits snugly within the overflow control valve body. It has a notch at its bottom. Rotating the valve handle 28 changes the valve state. When the valve is closed, multiphase fluid flows only to the coaxial line phase-based moisture meter. When the valve is open, gas in the upper layer can flow through the overflow control valve to the other side of the baffle, bypassing the coaxial line phase-based moisture meter, thereby achieving gas-liquid separation.

[0039] The oil well production fluid first enters the device from the device liquid inlet 1, flows through the upstream inclined baffle 2, the function of the inclined baffle is to make the gas and liquid more easily separated, and then enters the upstream oil-water-gas multiphase flow buffer chamber 3, where the gas and liquid are further separated by gravity. The gas phase fluid channel is controlled by adjusting the overflow control valve. When the overflow control valve is open, the gas phase flows into the upstream merging chamber 10 from the channel of the upstream overflow control valve 5. The liquid phase enters the upstream flow-water content measurement chamber 8 through the upstream flow-water content measurement chamber liquid inlet 4 to measure the water content. The measured liquid phase enters the upstream merging chamber 10 through the upstream flow-water content measurement chamber liquid outlet 9 to merge with the gas phase. The merged fluid flows into the downstream pipeline with the same structure through the connecting pipe 13, and the water content is measured again. The flow rate of the oil well production fluid is measured by a related flow meter composed of two coaxial line phase method water content meters.

[0040] Example 2

[0041] like Figure 3 As shown, it is a schematic diagram of an optimized and improved device of the present invention. Figure 1On the basis of this, the volume of the device is reduced. Structurally, the device liquid inlet 1 and the device liquid outlet 25 are adjusted to the same side, which is convenient for installation and debugging in actual applications. In addition, the upstream oil-water-gas multiphase flow buffer chamber 3 and the downstream oil-water-gas multiphase flow buffer chamber 15 are connected through the gas phase fluid channel 30. When the oil well production liquid flows into the device from the device liquid inlet 1, it will first be collected in the upstream oil-water-gas multiphase flow buffer chamber 3, and the gas-liquid separation will be achieved by gravity. The universal overflow control valve 29 will be opened, and the upper layer of gas will flow from the gas phase fluid channel 30 into the downstream oil-water-gas multiphase flow buffer chamber 15, and after merging with the liquid phase, it will flow out of the device through the device liquid outlet 25. The liquid phase enters the upstream flow-water content measurement chamber 8 through the liquid inlet of the upstream flow-water content measurement chamber 4 for measurement, flows out of the upstream coaxial line phase method water content meter 12 from the liquid outlet 9 of the upstream flow-water content measurement chamber, flows into the downstream flow-water content measurement chamber 20 for measurement through the connecting pipe 13, flows into the downstream oil-water-gas multiphase flow buffer chamber 15 through the liquid outlet 21 of the downstream flow-water content measurement chamber to merge with the gas phase, and finally flows out of the device through the liquid outlet 25 of the device to complete the measurement.

[0042] Example 3

[0043] As an embodiment of the present application, the present application includes an on-line measurement method for a gas overflow-controlled oil well, which uses a coaxial line phase method water cut meter to achieve integrated measurement of the water cut and flow rate of the oil well output fluid, including the following steps:

[0044] Step 1: The oil well production fluid flows into the upstream oil-water-gas multiphase flow buffer chamber through the liquid inlet of the device. In the upstream oil-water-gas multiphase flow buffer chamber, gas-liquid separation is carried out by gravity, with the gas phase in the upper layer and the liquid phase in the lower layer.

[0045] Step 2: Adjust the upstream overflow control valve. When the valve is open, the gas phase enters the upstream confluence chamber through the upstream overflow control valve, bypassing the upstream flow-water content measurement chamber. When the valve is closed, the gas phase and liquid phase enter the upstream flow-water content measurement chamber together, are measured by the upstream coaxial line phase method water content meter, and then flow into the upstream confluence chamber.

[0046] Step 3: The oil well production fluid flows into the upstream flow-water content measurement chamber, and the water content is measured using the upstream coaxial line phase method water content meter. This instrument is based on electromagnetic wave theory and uses the coaxial line as a sensitive element. When the mixed fluid is inside the sensor, it becomes a carrier for the electromagnetic wave to propagate in the coaxial line. The dielectric properties of the mixed fluid are related to the dielectric constant and conductivity of the oil and water phases, that is, the content of each phase. Since the dielectric constant and conductivity of formation water are much greater than those of oil and gas, the dielectric properties of the mixed fluid are mainly determined by the water content of the mixed medium. When a mixed fluid with different dielectric properties flows through the sensor, the change in the dielectric properties of the mixed fluid will cause the phase of the electromagnetic wave propagating in the coaxial line to change. Therefore, the water content can be measured by measuring the phase change of the electromagnetic wave propagating in the coaxial line.

[0047] Step 4: The oil well production fluid flowing out of the upstream flow-water-cut measurement chamber is combined in the upstream merging chamber and flows into the downstream pipeline, which has the same flow path as the upstream pipeline. The oil well production fluid will be measured for water cut again in the downstream pipeline before finally flowing out of the device.

[0048] Step 5: According to the structure of the device, after the oil well production fluid is measured in the upstream flow-water content measurement chamber, it takes a period of time to flow into the downstream flow-water content measurement chamber for re-measurement. The two water content signals are similar in terms of fluctuation changes, but there is a time difference in time. The data acquisition system collects the two water content signals and transmits the data to the computer for dynamic display and measurement. By performing a cross-correlation operation on the two water content signals, the cross-correlation function of the two signals can be obtained (in essence, it is to compare the similarity of the waveforms of the two water content signals under different delay values). When the waveforms of the two water content signals are the most similar, the cross-correlation function reaches its maximum value, and the delay value at this time is the time difference. Based on the calculated time difference, combined with the size of the pipeline and the distance between the upstream and downstream coaxial phase method water content meters, the flow rate of the oil well production fluid can be calculated.

[0049] Example 4:

[0050] As an embodiment of the present application, the present application includes a device for online metering of overflow-controlled oil wells, the device comprising: at least one processor; and a memory communicatively connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor so that the at least one processor can: output a start signal to the overflow control unit to open the overflow valve; receive water content signals of multiple branches acquired by a data acquisition unit; perform cross-correlation operations under the control of a first built-in program based on the acquired water content signals of the multiple branches to obtain a cross-correlation function; and obtain flow information of the oil well produced fluid based on the cross-correlation function, pipeline information, and the distance between the upstream and downstream sensors under the control of a second built-in program.

[0051] like Figure 4 The data acquisition unit is shown in Figure 1. The frequency signals output by the upstream coaxial line phase-method moisture meter 12 and the downstream coaxial line phase-method moisture meter 24 are transmitted via cables to the data acquisition card 31. The data acquisition card then transmits the data to the computer software for flow rate and moisture content calculation, while also dynamically displaying the real-time data.

[0052] Example 5

[0053] As an embodiment of the present application, the present application includes a medium for online metering of overflow-controlled oil wells, which stores computer-executable instructions, and the computer-executable instructions are configured to: output a start signal to the overflow control unit to open the overflow valve; receive water content signals of multiple branches acquired by a data acquisition unit; perform cross-correlation operations under the control of a first built-in program based on the acquired water content signals of the multiple branches to obtain a cross-correlation function; and obtain flow information of the oil well produced fluid based on the cross-correlation function, pipeline information, and the distance between the upstream and downstream sensors under the control of a second built-in program.

[0054] Example 6:

[0055] The present invention combines two coaxial phase-method water content meters to form a correlation flowmeter to measure flow. The measurement principle of the correlation flowmeter is as follows: Figure 5As shown, when the measured fluid flows steadily in the device, it will flow through the upstream and downstream coaxial line phase method moisture meters in sequence, and the upstream and downstream will generate moisture content measurement signals in sequence. The system consisting of the upstream and downstream coaxial line phase method moisture meters, the device and the measured fluid is regarded as a signal system. Let the moisture content signal generated by the upstream coaxial line phase method moisture meter be x(t), which is the input of the system; let the moisture content signal generated by the downstream coaxial line phase method moisture meter be y(t), which is the output of the system. Therefore, the problem of determining the time required for the fluid to travel from the upstream measurement section to the downstream measurement section can be reduced to the problem of the time required for a random signal to pass through a given system. The output signal y(t) of the system is cross-correlated with the input signal x(t) according to formula (1) to obtain the cross-correlation function R xy (τ), where τ is the time delay.

[0056]

[0057] Where T is the time interval.

[0058] Cross-correlation function R xy (τ) should be obtained under infinite time averaging. However, to meet the requirements of real-time measurement, the calculation of the cross-correlation function is only allowed to be performed within a limited time interval. In actual production, the flow rate of oil well production fluid is related to the pumping frequency. Affected by the pumping frequency, the coaxial line phase method water content meter signal changes periodically. In order to ensure the accuracy of the related flow calculation, the time interval T is approximately 3 times the signal period. The result of each calculation is the cross-correlation function R xy Estimated value of (τ)

[0059]

[0060] Cross-correlation function R xy (τ) represents the similarity of the waveforms of the two signals under different time delays. xy When (τ) reaches its maximum value, it means that the similarity between the two signals is the greatest. At this time, the corresponding time delay value τ0 is the transmission time of the signal x(t) in the system. The propagation speed of the signal x(t) in the system is v c It can be expressed as:

[0061]

[0062] Where, v c is the relevant speed; L is the sensor distance.

[0063] In specific implementation, the distribution of each phase in the oil-water two-phase flow or oil-water-gas three-phase flow in the pipeline changes during the flow process. Since the distance between the upstream and downstream sensors is very short, it can be approximately considered that the distribution of each phase is constant. Under ideal flow conditions, the flow velocity of the fluid at each point on the cross section of the pipeline is equal, and the volume average flow velocity v of the measured fluid is cp The relevant speed v c express:

[0064]

[0065] Therefore, the volume flow rate Q of the measured fluid can be expressed as:

[0066]

[0067] Where K is the velocity deviation coefficient; A is the cross-sectional area of ​​the pipe.

[0068] The numerator in formula (5) is a fixed value. According to the test data, the numerator is finally determined to be a constant. Therefore, the volume flow rate Q of the measured fluid can be expressed as:

[0069]

[0070] Example 7:

[0071] Based on the device and method of the present invention, experiments were carried out at an oil field production site. Figure 6 is the field test data curve, from Figure 6 As can be seen in the figure, the signals from the upstream and downstream coaxial line phase-based moisture meter exhibit a certain delay. Therefore, the method of the present invention can be used to measure flow, demonstrating its feasibility. Field tests using a turbine flowmeter and the device of the present invention were performed to measure flow. The test results are shown in Table 1.

[0072] Table 1 Field test results

[0073]

[0074] Compared to traditional metering methods, this present invention utilizes the correlation between two water-cut signals to determine the flow rate of oil well production fluid. This method has the advantages of no moving parts, reducing the possibility of mechanical failure, high stability, and independence from the fluid's inherent conditions, making it widely applicable. The present invention is applicable to both oil-water two-phase flow and oil-water-gas three-phase flow, making it suitable for surface metering in oil wells.

[0075] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0076] In the above embodiments of the present invention, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0077] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only exemplary. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0078] The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0079] In addition, the functional units in the various embodiments of the present invention may be integrated into a single processing unit, each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or software functional units.

[0080] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, magnetic disk or optical disk, etc. Various media that can store program codes.

[0081] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A gas overflow control type oil well online metering device, comprising: A gas-liquid separation unit and a flow-water-cut measurement unit; characterized in that the gas-liquid separation unit performs gas-liquid separation via a multiphase flow buffer chamber and an overflow control valve; the flow-water-cut measurement unit comprises: an upstream coaxial line phase-method water-cut meter and a downstream coaxial line phase-method water-cut meter; the coaxial line phase-method water-cut meter directly measures the water cut of the oil well output fluid; the online metering device comprises the combined upstream coaxial line phase-method water-cut meter and the downstream coaxial line phase-method water-cut meter; the device comprises: a device liquid inlet, an upstream pipeline, a downstream pipeline connected to the upstream pipeline and having the same structure as the upstream pipeline, and a device liquid outlet; The upstream pipeline includes: an upstream oil-water-gas multiphase flow buffer chamber, an upstream flow-water content measurement chamber, and an upstream merging chamber; the upstream oil-water-gas multiphase flow buffer chamber and the upstream merging chamber are separated by an upstream baffle; An upstream overflow control valve is also provided at the top of the upstream oil-water-gas multiphase flow buffer chamber; the upstream baffle is coaxially arranged with the upstream overflow control valve, and an opening is provided at the center of the upstream baffle; an upstream coaxial line phase method water content meter passes horizontally through the central opening provided on the upstream baffle; The upstream coaxial line phase method moisture meter is provided with the upstream flow-water content measurement chamber; the upstream oil-water-gas multiphase flow buffer chamber is provided with the upstream flow-water content measurement chamber liquid inlet of the upstream coaxial line phase method moisture content meter; the upstream flow-water content measurement chamber is also provided with an upstream flow-water content measurement chamber liquid outlet, and the upstream flow-water content measurement chamber liquid outlet is provided in the upstream confluence chamber; the upstream confluence chamber is connected to the downstream pipeline through a connecting pipe; The metering device further comprises an upstream inclined baffle which is arranged in the upstream oil-water-gas multiphase flow buffer chamber and at the liquid inlet of the device.

2. The gas overflow control type oil well online metering device according to claim 1, characterized in that: The upstream coaxial line phase method moisture meter is fixed to the tail end of the upstream pipeline through a flange. At the same time, a spring passes through the interior of the upstream coaxial line phase method moisture meter, and the spring is compressed by force to fix the packing to achieve sealing.

3. The gas overflow control type oil well online metering device according to claim 1, characterized in that: When the upstream overflow control valve is opened, the gas phase flows from the upstream overflow control valve into the upstream confluence chamber; The liquid phase enters the upstream flow-water content measurement chamber through the liquid inlet of the upstream flow-water content measurement chamber to measure the water content. The measured liquid phase enters the upstream merging chamber through the liquid outlet of the upstream flow-water content measurement chamber and merges with the gas phase. When the upstream overflow control valve is closed, the gas phase and the liquid phase enter the upstream flow-water content measurement chamber together, and flow into the upstream merging chamber after being measured by the upstream coaxial line phase method water content meter.

4. An on-line measurement method for gas overflow control oil wells, using the device according to any one of claims 1 to 3, to achieve integrated measurement of the water content and flow rate of the oil well output fluid using a coaxial line phase method water content meter, characterized in that: The following steps are involved: The fluid to be measured is separated into gas and liquid by a gas-liquid separation unit, and the gas phase is controlled by an overflow control unit to prevent it from entering the flow-water content measurement unit, and the liquid phase sequentially enters multiple flow-water content measurement units with a certain distance therebetween, and then the flow-water content measurement units respectively measure the water content signals of the multiple branches; the data acquisition unit acquires the water content signals of the multiple branches and transmits the acquired signals to the computer unit; further, the calculation unit obtains the cross-correlation operation of the water content signals of the multiple branches to obtain the cross-correlation function of the multiple branch signals; the flow information of the oil well produced liquid is obtained based on the cross-correlation function, pipeline information, and the distance between the upstream coaxial line phase method water content meter and the downstream coaxial line phase method water content meter; the overflow control unit controls the fluid channel of the gas phase by an overflow control valve; when the overflow control valve is opened, the gas phase does not pass through the flow-water content measurement unit; when the overflow control valve is closed, the gas phase and the liquid phase enter the flow-water content measurement unit together.

5. The on-line metering method for gas overflow control oil wells according to claim 4, characterized in that: In the gas-liquid separation unit, gas-liquid separation is performed by gravity; wherein the gas phase is in the upper layer and the liquid phase is in the lower layer.

6. The on-line metering method for gas overflow control oil wells according to claim 4, characterized in that: The flow-water content measurement unit adopts a coaxial line phase method water content meter to measure the water content, and obtains the water content of the fluid to be measured by detecting the change in the phase of the electromagnetic wave propagating in the coaxial line.

7. An equipment for online metering of gas overflow control oil wells, using the device according to any one of claims 1 to 3, characterized in that: The device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to: Outputting a start signal to the overflow control unit to open the overflow valve; Receiving multi-branch moisture content signals acquired by a data acquisition unit; According to the obtained multi-branch moisture content signals, a cross-correlation operation is performed under the control of a first built-in program to obtain a cross-correlation function; Under the control of the second built-in program, the flow rate information of the oil well produced fluid is obtained according to the cross-correlation function, pipeline information, and the distance between the upstream coaxial line phase method water cut meter and the downstream coaxial line phase method water cut meter.

8. A medium for online metering of a gas overflow control oil well, storing computer-executable instructions, and applying the device according to any one of claims 1 to 3, characterized in that: The computer executable instructions are configured to: Outputting a start signal to the overflow control unit to open the overflow valve; Receiving multi-branch moisture content signals acquired by a data acquisition unit; Based on the acquired multi-branch water cut signals, a cross-correlation operation is performed under the control of a first built-in program to obtain a cross-correlation function; under the control of a second built-in program, flow information of the oil well produced fluid is obtained based on the cross-correlation function, pipeline information, and the distance between the upstream coaxial line phase method water cut meter and the downstream coaxial line phase method water cut meter.

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