Wellhead water content measuring method based on dual-frequency microwave directional antenna sensor

Abstract

The invention discloses a wellhead water content measuring method based on a double-frequency microwave directional antenna sensor, and the double-frequency microwave directional antenna sensor comprises two first microwave directional antennas, two second microwave directional antennas, an annular disc and a pipe body, the annular disc is annular, the annular disc is sleeved outside the pipe body and is fixedly installed with the pipe body, and the pipe body is fixedly installed on the annular disc. The two first microwave directional antennas are located above the annular disc, and the two second microwave directional antennas are located below the annular disc; the two sides of the pipe body in the radial direction are each provided with one first microwave directional antenna, and the two sides of the pipe body in the radial direction are each provided with one second microwave directional antenna. Dielectric constants and dielectric losses of oil and water are remarkably different, so that phase deviation occurs when a high-frequency microwave signal is propagated in an oil-water mixed medium, and the water content in oil-water two-phase flow is obtained by analyzing phase voltage signals with different frequencies through a double-frequency microwave directional antenna sensor.

Description

Technical Field

[0001] The invention belongs to the field of oilfield exploitation and multiphase fluid content measurement, and in particular relates to a wellhead water content measurement method based on a dual-frequency microwave directional antenna sensor. Background Art

[0002] In oilfield production, accurate measurement of wellhead water cut is crucial for increasing production, optimizing oil-gas separation, and enabling real-time monitoring. In oilfields with high water cuts (e.g., above 70%), accurate water cut measurement plays a crucial role in oil-gas separation, pipeline monitoring, and oil production equipment optimization. Currently, wellhead water cut measurement technologies primarily include capacitance, conductivity, X-ray, and microwave-based methods. Conductivity and capacitance sensors have limited resolution when measuring high water cuts. Furthermore, conductivity sensors are significantly affected by salinity fluctuations. Gamma ray methods, however, are subject to high cost and radiation issues, limiting their widespread application.

[0003] Compared to traditional methods, microwave technology's advantages in measuring water content lie in its non-contact nature, strong penetration, and high sensitivity. Microwave signals can penetrate oil-water mixtures, and the water content is inferred based on the phase shift of the signal as it propagates through the medium. This provides high accuracy, particularly when the water content of the oil-water mixture is high, providing precise real-time monitoring results. Microwave technology enables continuous monitoring without disrupting the production process, effectively controlling and optimizing the state of the oil-water fluid.

[0004] However, despite the numerous advantages of microwave technology, existing microwave sensors still have some shortcomings, especially when dealing with oil-water two-phase flows with high water content, facing the following challenges:

[0005] 1. Single-frequency microwave sensors have limitations. Currently, most microwave sensors use a single-frequency microwave signal to measure water content. However, due to the complexity of oil-water mixtures, especially when the water content is close to or above 70%, a single-frequency signal cannot accurately distinguish small changes in water content. The relationship between the phase change of a single-frequency signal and the water content is usually nonlinear. In addition, other factors in the oil-water flow state (such as flow velocity, bubbles, solid impurities, etc.) may also interfere with the measurement results. Therefore, single-frequency microwave sensors have low accuracy and stability in such complex media.

[0006] 2. The frequency selection is relatively fixed. Existing microwave sensors are mostly based on fixed frequency design, with fixed frequency selection and poor adaptability to different media. Due to the differences in dielectric constant and dielectric loss between oil and water at different frequencies, selecting a single frequency signal cannot effectively cover all measurement ranges and complex working conditions. Especially in the dynamic changes of multiphase fluids, the adaptability and accuracy of existing sensors are easily limited.

[0007] 3. Existing sensors lack stability and interference resistance. In practical applications, factors such as temperature, pressure, pipeline structure, and flow rate in the wellhead environment can affect microwave signal propagation, leading to measurement errors. Furthermore, electromagnetic interference in the wellhead environment can cause fluctuations in measurement results, impacting sensor stability and reliability. Existing microwave sensors have a weak ability to suppress external interference, especially in oil-water mixtures with high water content. Sensors are susceptible to external interference, resulting in reduced data reliability. Summary of the Invention

[0008] In view of the deficiencies in the prior art, an object of the present invention is to provide a dual-frequency microwave directional antenna sensor.

[0009] Another object of the present invention is to provide a dual-frequency microwave directional antenna sensor for use in detecting liquids.

[0010] The present invention is achieved through the following technical solutions.

[0011] A dual-frequency microwave directional antenna sensor includes: two first microwave directional antennas, two second microwave directional antennas, an annular disk, and a tube body. The annular disk is annular and is sleeved on the tube body and fixed to the tube body. The two first microwave directional antennas are located above the annular disk, and the two second microwave directional antennas are located below the annular disk.

[0012] One first microwave directional antenna is provided on each side of the tube body along the radial direction, and the two first microwave directional antennas are symmetrically arranged along the axis of the tube body; one second microwave directional antenna is provided on each side of the tube body along the radial direction, and the two second microwave directional antennas are symmetrically arranged along the axis of the tube body;

[0013] The first microwave directional antenna includes a rectangular parallelepiped sheet, on which two identical first hollow areas are formed, and the two first hollow areas are arranged along the length direction of the rectangular parallelepiped sheet;

[0014] The second microwave directional antenna includes a rectangular parallelepiped sheet, on which two identical second hollow areas are formed, and the two second hollow areas are arranged along the length direction of the rectangular parallelepiped sheet;

[0015] In the above technical solution, each first hollow area / second hollow area is a rectangle and the four corners of the rectangle are rounded.

[0016] In the above technical solution, the longer sides of the first hollow area / the second hollow area are arranged parallel to the longer sides of the rectangular parallelepiped sheet.

[0017] In the above technical solution, each of the first microwave directional antenna and the second microwave directional antenna is respectively arranged horizontally, the length directions of the two first microwave directional antennas are parallel, and the length directions of the two second microwave directional antennas are parallel;

[0018] In the above technical solution, each rectangular sheet is fixed with a radio frequency connection port at the midpoint position on the side surface along its length direction, which is used to connect the radio frequency line; wherein, a first microwave directional antenna serves as a transmitting antenna, and another first microwave directional antenna serves as a receiving antenna; a second microwave directional antenna serves as a transmitting antenna, and another second microwave directional antenna serves as a receiving antenna; the radio frequency line connected to the transmitting antenna is used to transmit the high-frequency microwave signal to the transmitting antenna; and the radio frequency line connected to the receiving antenna is used to output the high-frequency microwave signal captured by the receiving antenna.

[0019] In the above technical solution, the two first microwave directional antennas are fixed to the tube body through two first support frames, the two first support frames form a ring and are fixed to each other, and the tube body is fixed within the ring formed by the two first support frames; the two second microwave directional antennas are fixed to the tube body through two second support frames, the two second support frames form a ring and are fixed to each other, and the tube body is fixed within the ring formed by the two second support frames.

[0020] In the above technical solution, a cavity for accommodating the first microwave directional antenna is provided in each first supporting frame, and a cavity for accommodating the second microwave directional antenna is provided in each second supporting frame.

[0021] In the above technical solution, a first opening is provided on the first support frame, which is connected to the inner cavity of the first support frame, and a first baffle is installed on the first opening; a second opening is provided on the second support frame, which is connected to the inner cavity of the second support frame, and a second baffle is installed on the second opening.

[0022] In the above technical solution, a first flange is fixedly mounted on the top of the tube body, and a second flange is fixedly mounted on the bottom of the tube body.

[0023] In the above technical solution, a first shielding cover is installed outside the tube body above the annular disk, and a second shielding cover is installed outside the tube body below the annular disk. The first shielding cover is used to shield the influence of interference signals on the first microwave directional antenna, and the second shielding cover is used to shield the influence of interference signals on the second microwave directional antenna.

[0024] The invention discloses an application of a dual-frequency microwave directional antenna sensor in detecting the water content in an oil-water mixture.

[0025] In the above technical solution, a dual-frequency microwave directional antenna sensor is used to obtain the relationship between the dual-frequency phase voltage signal and the water content in the oil-water mixture, wherein each group of dual-frequency phase voltage signals includes: the phase voltage values ​​of two first microwave directional antennas and the phase voltage values ​​of two second microwave directional antennas; each time the dual-frequency microwave directional antenna sensor collects the dual-frequency phase voltage signal of the oil-water mixture, the phase change of the two first microwave directional antennas is used as the phase voltage value of the two first microwave directional antennas, and the phase change of the two second microwave directional antennas is used as the phase voltage value of the two second microwave directional antennas.

[0026] The dual-frequency phase voltage signal of the liquid to be measured is collected by a dual-frequency microwave directional antenna sensor, and the dual-frequency phase voltage signal of the liquid to be measured is substituted into the relationship to obtain the water content of the liquid to be measured.

[0027] The present invention has the following advantages due to the adoption of the above technical solution:

[0028] The dual-frequency microwave directional antenna sensor is a non-contact sensor, eliminating direct contact between the first and second microwave directional antennas and the medium, reducing the risk of antenna wear and damage. The dual-frequency microwave directional antenna sensor has excellent anti-interference capabilities and stability, providing a foundation for subsequent moisture content prediction.

[0029] 2. The dual-frequency microwave directional antenna sensor used is particularly suitable for high water-cut wells that are common in China's onshore oil wells (Dakuang H. On concepts, strategies and techniques to the secondary development of China's high water-cut oilfields [J]. Petroleum Exploration and Development, 2010, 37 (5): 583-591.), and the error of the water cut prediction value is within 3%. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the structure of the first microwave directional antenna, wherein the upper part is a three-dimensional diagram and the lower part is a plan view;

[0031] Figure 2 Schematic diagram of the structure of the second microwave directional antenna, wherein the upper part is a three-dimensional diagram and the lower part is a plan view;

[0032] Figure 3 It is a right-angle cross-sectional view of a dual-frequency microwave directional antenna sensor (the first microwave directional antenna, the second microwave directional antenna, the first shielding cover, and the second shielding cover are not shown);

[0033] Figure 4 It is a partial enlarged view of a right-angle cross-sectional view of a dual-frequency microwave directional antenna sensor (showing the first microwave directional antenna and the second microwave directional antenna, but not showing the first shielding cover and the second shielding cover);

[0034] Figure 5 This is a side view of the dual-frequency microwave directional antenna sensor (the first shielding cover and the second shielding cover are transparent);

[0035] Figure 6 This is a front view of the dual-frequency microwave directional antenna sensor (the first shielding cover and the second shielding cover are transparent);

[0036] Figure 7 Result diagram of each set of dual-frequency phase voltage signals of the dual-frequency phase voltage data set;

[0037] Figure 8 Obtain a fitting curve diagram of dual-frequency phase voltage signal and moisture content for the dual-frequency microwave directional antenna sensor;

[0038] Figure 9 is a perspective view of two first support frames and two first microwave directional antennas embedded therein;

[0039] Figure 10 Schematic diagram of the three-dimensional structure of the dual-frequency microwave directional antenna sensor (the first shielding cover, the second shielding cover, the first flange and the second flange are not shown);

[0040] Figure 11 This is a structural diagram of a dual-frequency microwave directional antenna sensor (the first shielding cover and the second shielding cover are non-transparent).

[0041] Among them, 1: first microwave directional antenna, 2: second microwave directional antenna, 3: tube body, 4: first support frame, 5: second support frame, 6: first baffle, 7: second baffle, 8: wire outlet, 9: annular disk, 10: first shielding cover, 11: second shielding cover, 12: first flange, 13: second flange. DETAILED DESCRIPTION

[0042] A method for measuring water content at a wellhead based on a dual-frequency microwave directional antenna sensor of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0043] Example 1

[0044] like Figures 1 to 6 、 Figures 9 to 11As shown, a dual-frequency microwave directional antenna sensor includes: two first microwave directional antennas 1, two second microwave directional antennas 2, an annular disk 9, and a tube body 3. The annular disk 9 is annular and is sleeved outside the tube body and fixed to the tube body. The two first microwave directional antennas are located above the annular disk, and the two second microwave directional antennas are located below the annular disk. The annular disk 9 is used to prevent mutual interference between the first microwave directional antennas and the second microwave directional antennas.

[0045] A first microwave directional antenna is provided on each side of the tube body along the radial direction, and the two first microwave directional antennas are symmetrically arranged along the axis of the tube body; a second microwave directional antenna is provided on each side of the tube body along the radial direction, and the two second microwave directional antennas are symmetrically arranged along the axis of the tube body;

[0046] The first microwave directional antenna includes a rectangular sheet with two identical first hollow areas (through holes) formed therein. The first hollow areas of the two first microwave directional antennas are arranged along the length of the rectangular sheet, each first hollow area is rectangular, and the four corners of the rectangle are rounded. The second microwave directional antenna includes a rectangular sheet with two identical second hollow areas (through holes) formed therein. The two second hollow areas are arranged along the length of the rectangular sheet, each second hollow area is rectangular, and the four corners of the rectangle are rounded. The longer sides of the first hollow areas are parallel to the longer sides of the rectangular sheet of the first microwave directional antenna. The longer sides of the second hollow areas are parallel to the longer sides of the rectangular sheet of the second microwave directional antenna.

[0047] Each first microwave directional antenna and second microwave directional antenna are respectively arranged horizontally, with the length directions of the two first microwave directional antennas being parallel, and the length directions of the two second microwave directional antennas being parallel; a radio frequency connection port is fixed at the midpoint of the side surface along the length direction of each rectangular parallelepiped piece, for connecting a radio frequency line; wherein, one first microwave directional antenna 1 serves as a transmitting antenna, and another first microwave directional antenna 1 serves as a receiving antenna; one second microwave directional antenna 2 serves as a transmitting antenna, and another second microwave directional antenna 2 serves as a receiving antenna; the radio frequency line connected to the transmitting antenna is used to transmit the high-frequency microwave signal (input from the back-end data acquisition circuit) to the transmitting antenna; the radio frequency line connected to the receiving antenna is used to output the high-frequency microwave signal captured by the receiving antenna (i.e., transmitted to the back-end data acquisition circuit);

[0048] The two first microwave directional antennas are fixed to the tube body via two first support frames 4. The two first support frames 4 form a ring and are fixed to each other. The tube body is fixed within the ring formed by the two first support frames 4. The two second microwave directional antennas are fixed to the tube body via two second support frames 5. The two second support frames 5 form a ring and are fixed to each other. The tube body is fixed within the ring formed by the two second support frames 5.

[0049] Preferably, each first support frame 4 is provided with a cavity for placing a first microwave directional antenna, and each second support frame 4 is provided with a cavity for placing a second microwave directional antenna; Figure 3 As shown, for better installation, the first support frame is provided with a first opening, which is connected to the inner cavity of the first support frame, and a first baffle 6 is installed on the first opening; the second support frame is provided with a second opening, which is connected to the inner cavity of the second support frame, and a second baffle 7 is installed on the second opening. The first baffle is opened, and the first microwave directional antenna can be placed into the cavity of the first support frame through the first opening; the second baffle is opened, and the second microwave directional antenna can be placed into the cavity of the second support frame through the second opening; the perspective view of the two first microwave directional antennas after being installed in the two first support frames 4 is shown in FIG. Figure 9 shown.

[0050] A first flange 12 is fixedly mounted on the top of the tube body, and a second flange 13 is fixedly mounted on the bottom of the tube body;

[0051] A first shielding cover 10 is installed between the first flange and the annular disk, and a second shielding cover 11 is installed between the second flange and the annular disk. The first shielding cover 10 is threadedly connected to the first flange, and the second shielding cover is threadedly connected to the second flange. The first shielding cover 10 is used to shield the first microwave directional antenna from interference signals, while the second shielding cover is used to shield the second microwave directional antenna from interference signals, thereby enhancing signal stability and measurement accuracy. The annular disk 9 is provided with an outlet 8 for the radio frequency cable.

[0052] The optimal operating frequency of the first microwave directional antenna 1 is 1.345 GHz, which is suitable for the transmission of lower frequency signals and can effectively penetrate the oil-water mixed medium; the optimal operating frequency of the second microwave directional antenna 2 is 2.0666 GHz, which is suitable for the transmission of higher frequency signals, has higher resolution and sensitivity, and is suitable for more precise water content measurement.

[0053] Among them, a vector network analyzer (VNA) was used to perform response tests on the S21 parameter (transmission coefficient phase) of the antenna under full oil and full water conditions. The antenna was the first microwave directional antenna 1 or the second microwave directional antenna 2. According to the response tests, the first microwave directional antenna 1 and the second microwave directional antenna 2 had the highest phase sensitivity at frequencies of 1.325 GHz and 2.066 GHz, respectively, with a variation amplitude greater than 60°. Therefore, 1.325 GHz and 2.066 GHz were set as the optimal operating frequencies of the first microwave directional antenna 1 and the second microwave directional antenna 2, respectively.

[0054] The first and second microwave directional antennas are both made of FR-4 material. FR-4 material has low dielectric loss and a high dielectric constant, which facilitates efficient transmission of microwave signals and reduces signal attenuation caused by dielectric influences.

[0055] The tube body 3 is made of PEEK material;

[0056] The first support frame 4 and the second support frame 5 have the same size of 118 mm×65 mm×16 mm.

[0057] The rectangular plate of the first microwave directional antenna is 80 mm long, 40 mm wide, and 2 mm thick. Each first hollowed-out area of ​​the first microwave directional antenna measures 35 mm x 30 mm. The rectangular plate of the second microwave directional antenna is 70 mm long, 40 mm wide, and 2 mm thick. Each second hollowed-out area of ​​the second microwave directional antenna measures 30 mm x 25 mm. The annular disk 9 has an outer diameter of 210 mm and a thickness of 15 mm, and an inner diameter of 70 mm. The first and second shielding covers 10 and 11 each have an inner diameter of 190 mm, an outer diameter of 210 mm, and a length of 75 mm. The tube 3 has a length of 200 mm, an outer diameter of 70 mm, and an inner diameter of 50 mm. The first and second baffles 6 and 7 are made of 3D-printed photosensitive resin and are both 1 mm thick.

[0058] Example 2

[0059] A method for obtaining a dual-frequency phase voltage data set, comprising:

[0060] The tube body of the dual-frequency microwave directional antenna sensor of Example 1 is installed on a wellhead pipeline (it can be installed through the first flange or the second flange), and the wellhead water cut of the oil-water two-phase fluid in the wellhead pipeline is adjusted to 70% to 100%, so that the oil-water two-phase fluid in the wellhead pipeline flows through the tube body of the dual-frequency microwave directional antenna sensor. Within the wellhead water cut range of 70% to 100%, each integer wellhead water cut is used as an operating point, and the dual-frequency microwave directional antenna sensor collects five groups of original dual-frequency phase voltage signals at each operating point. When collecting each group of original dual-frequency phase voltage signals, the microwave source divides the high-frequency microwave signal into two paths through a power divider: a first high-frequency microwave signal and a second high-frequency microwave signal. The first high-frequency microwave signal transmits the high-frequency microwave signal to the transmitting antenna through a radio frequency line (connected to the transmitting antenna); the radio frequency line connected to the receiving antenna outputs the high-frequency microwave signal captured by the receiving antenna. The second high-frequency microwave signal (used as a reference) and the high-frequency microwave signal captured by the receiving antenna are used as a phase detector (Phase The phase detector converts the phase difference between the two input signals into a voltage signal. The obtained voltage signal is the phase voltage value / original phase voltage value. Each set of original dual-frequency phase voltage signals includes the original phase voltage values ​​of the two first microwave directional antennas and the original phase voltage values ​​of the two second microwave directional antennas. The average value of the original phase voltage values ​​of the two first microwave directional antennas and the average value of the original phase voltage values ​​of the two second microwave directional antennas in the five sets of original dual-frequency phase voltage signals are calculated.

[0061] The average value of the five "original phase voltage values ​​of the two first microwave directional antennas" is used as the phase voltage value V1 of the first microwave directional antenna, and the average value of the five "original phase voltage values ​​of the two second microwave directional antennas" is used as the phase voltage value V2 of the second microwave directional antenna. The phase voltage value V1 of the first microwave directional antenna and the phase voltage value V2 of the second microwave directional antenna at the same operating point constitute a set of dual-frequency phase voltage signals. The operating points with a wellhead water cut of 70% to 100% constitute a total of Figure 7 31 sets of dual-frequency phase voltage signals are shown as dual-frequency phase voltage data sets; according to Figure 7 From the error bars of each operating point, it can be seen that the standard deviation of the five groups of original dual-frequency phase voltage signals collected at each operating point is within 3%. Therefore, the dual-frequency microwave directional antenna sensor has high stability.

[0062] Among them, the method for the dual-frequency microwave directional antenna sensor to collect a set of original dual-frequency phase voltage signals is as follows: the two transmitting antennas of the dual-frequency microwave directional antenna sensor simultaneously transmit high-frequency microwave signals of different frequencies (the operating frequency of the first microwave directional antenna 1 is 1.345 GHz, and the operating frequency of the second microwave directional antenna 2 is 2.0666 GHz). The two high-frequency microwave signals of different frequencies are captured by the corresponding receiving antennas after passing through the oil-water two-phase fluid. The phase changes between the high-frequency microwave signals emitted by the transmitting antenna and the high-frequency microwave signals received by the receiving antenna are measured respectively. The phase changes of the two first microwave directional antennas are used as the original phase voltage values ​​of the two first microwave directional antennas, and the phase changes of the two second microwave directional antennas are used as the original phase voltage values ​​of the two second microwave directional antennas.

[0063] The dual-frequency microwave directional antenna sensor can be used to collect raw dual-frequency phase voltage signals based on the following: the dielectric constants and dielectric losses of oil and water are significantly different. Therefore, the propagation of high-frequency microwave signals in the oil-water mixture will cause phase shifts. The phase change reflects that the propagation speed of the high-frequency microwave signal in the medium is closely related to the oil-water ratio. By analyzing the phase voltage signals of different frequencies, the water content in the oil-water two-phase flow can be obtained.

[0064] Advantages of using a dual-frequency microwave directional antenna sensor: The dielectric constant and dielectric loss of oil and water vary significantly at different frequencies. Single-frequency measurement often cannot accurately reflect changes in water content, especially when the water content values ​​of adjacent operating points are relatively close, making it difficult for single-frequency measurement to distinguish similar water content values. The dual-frequency measurement of the dual-frequency microwave directional antenna sensor of the present invention can provide phase voltage signals at two different frequencies. By comparing the phase changes of the two frequencies, operating points with similar water content can be effectively distinguished, thereby improving the accuracy of the water content prediction value. The use of a dual-frequency microwave directional antenna sensor provides more information and constraints, effectively eliminating errors that may occur in single-frequency measurement.

[0065] Example 3

[0066] Based on Example 2, a method for constructing a water content bivariate quadratic polynomial model includes:

[0067] S1, construct a water content bivariate quadratic polynomial model, with water content WC(V1, V2) as the dependent variable. The water content bivariate quadratic polynomial model is specifically:

[0068]

[0069] Among them, a, b, c, d, e and f are coefficients to be solved, V1 is the average value of the five "original phase voltage values ​​of the two first microwave directional antennas", and V2 is the average value of the five "original phase voltage values ​​of the two second microwave directional antennas".

[0070] S2, using the dual-frequency phase voltage signal in the dual-frequency phase voltage data set, through the least squares method ( Least squares methods [J]. Handbook of numerical analysis, 1990, 1: 465-652.) Solve the coefficients (a, b, c, d, e and f) of the water content two-variable quadratic polynomial model and obtain a = -35.93, b = 20.53, c = 1.672, d = 96.48, e = -16.49, f = 10.69. Therefore, the water content two-variable quadratic polynomial model is specifically:

[0071]

[0072] like Figure 8 As shown in the above formula, the fitting curve of the phase voltage value V1, phase voltage value V2 and moisture content of the dual-frequency microwave directional antenna sensor can be obtained, which is obtained by Figure 8 It can be seen that the water content two-variable quadratic polynomial model can describe the nonlinear relationship between the phase voltage value V1, the phase voltage value V2 and the water content, reflecting the highly nonlinear characteristics of the dielectric properties and frequency dependence of water.

[0073] Calculate R for model evaluation 2 The values ​​were used to verify the fitting effect of the water content bivariate quadratic polynomial model, R 2 =99.69%. In summary, the fitting effect of the water content binary quadratic polynomial model is very good, which can accurately reflect the relationship between the dual-frequency phase voltage signal and the water content and has high prediction accuracy.

[0074] Example 4

[0075] A method for measuring water content at a wellhead based on a dual-frequency microwave directional antenna sensor, comprising:

[0076] S1, installing the tube of the dual-frequency microwave directional antenna sensor on the wellhead pipeline (so that the oil-water two-phase fluid in the wellhead pipeline passes through the tube), causing the dual-frequency microwave directional antenna sensor to collect multiple sets of original dual-frequency phase voltage signals, and simultaneously sampling the oil-water two-phase fluid in the wellhead pipeline, and obtaining the actual wellhead water content corresponding to each set of original dual-frequency phase voltage signals through analysis;

[0077] S2, substituting the "original phase voltage values ​​of the two first microwave directional antennas" in each set of collected original dual-frequency phase voltage signals into the phase voltage value V1 in the water cut binary quadratic polynomial model of Example 3, and substituting the "original phase voltage values ​​of the two second microwave directional antennas" into the phase voltage value V2 in the water cut binary quadratic polynomial model of Example 3, to obtain the wellhead water cut prediction value corresponding to the set of original dual-frequency phase voltage signals;

[0078] Comparing the actual wellhead water cut values ​​and the predicted wellhead water cut values ​​corresponding to each set of original dual-frequency phase voltage signals, it can be seen that the predicted wellhead water cut values ​​are very close to the actual wellhead water cut values, and the error of more than 95% of the wellhead water cut prediction values ​​is within 3%.

[0079] In summary, the prediction of wellhead water cut based on the dual-frequency microwave directional antenna sensor combined with the water cut binary quadratic polynomial model can significantly improve the prediction accuracy of water cut in high water cut wells. Compared with the single-frequency measurement method (single-frequency microwave directional antenna sensor), the wellhead water cut measurement method of the present invention not only improves the accuracy of the prediction, but also enhances the adaptability to complex water cut conditions.

[0080] The above is an exemplary description of the present invention. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by other skilled in the art without expending creative labor falls within the scope of protection of the present invention.

Claims

1. A dual-frequency microwave directional antenna sensor, characterized in that: include: Two first microwave directional antennas (1), two second microwave directional antennas (2), an annular disk (9) and a tube body (3), wherein the annular disk (9) is annular and is sleeved outside the tube body (3) and fixed to the tube body (3), the two first microwave directional antennas (1) are located above the annular disk (9), and the two second microwave directional antennas (2) are located below the annular disk (9); Wherein, one of the first microwave directional antennas (1) is provided on each of the two radial sides of the tube body (3), and the two first microwave directional antennas (1) are symmetrically arranged along the axis of the tube body (3); one of the second microwave directional antennas (2) is provided on each of the two radial sides of the tube body (3), and the two second microwave directional antennas (2) are symmetrically arranged along the axis of the tube body (3); The first microwave directional antenna (1) comprises a rectangular parallelepiped sheet, on which two identical first hollow areas are formed, and the two first hollow areas are arranged along the length direction of the rectangular parallelepiped sheet; The second microwave directional antenna (2) comprises a rectangular parallelepiped sheet. Two identical second hollow areas are formed on the rectangular parallelepiped sheet of the second microwave directional antenna (2). The two second hollow areas are arranged along the length direction of the rectangular parallelepiped sheet.

2. The dual-frequency microwave directional antenna sensor according to claim 1, characterized in that: Each rectangular sheet is fixed with a radio frequency connection port at a midpoint position on a side surface along its length direction, for connecting a radio frequency line; wherein a first microwave directional antenna (1) serves as a transmitting antenna, and another first microwave directional antenna (1) serves as a receiving antenna; a second microwave directional antenna (2) serves as a transmitting antenna, and another second microwave directional antenna (2) serves as a receiving antenna; the radio frequency line connected to the transmitting antenna is used to transmit a high-frequency microwave signal to the transmitting antenna; and the radio frequency line connected to the receiving antenna is used to output the high-frequency microwave signal captured by the receiving antenna.

3. The dual-frequency microwave directional antenna sensor according to claim 1, characterized in that: The two first microwave directional antennas (1) are fixedly mounted on the tube body (3) via two first support frames (4), the two first support frames (4) form a ring and are fixed to each other, and the tube body (3) is fixed within the ring formed by the two first support frames (4); the two second microwave directional antennas (2) are fixedly mounted on the tube body (3) via two second support frames (5), the two second support frames (5) form a ring and are fixed to each other, and the tube body (3) is fixed within the ring formed by the two second support frames (5).

4. The dual-frequency microwave directional antenna sensor according to claim 3, characterized in that: Each first support frame (4) is provided with a cavity for accommodating a first microwave directional antenna (1), and each second support frame (5) is provided with a cavity for accommodating a second microwave directional antenna (2).

5. The dual-frequency microwave directional antenna sensor according to claim 4, characterized in that: The first support frame (4) is provided with a first opening, the first opening being in communication with the inner cavity of the first support frame (4), and a first baffle (6) being mounted on the first opening; the second support frame (5) is provided with a second opening, the second opening being in communication with the inner cavity of the second support frame (5), and a second baffle (7) being mounted on the second opening.

6. The dual-frequency microwave directional antenna sensor according to claim 1, characterized in that: A first flange (12) is fixedly mounted on the top of the tube body (3), and a second flange (13) is fixedly mounted on the bottom of the tube body (3).

7. The dual-frequency microwave directional antenna sensor according to claim 1, characterized in that: Each first hollow area / second hollow area is a rectangle, and the four corners of the rectangle are rounded; the longer sides of the first hollow area / second hollow area are parallel to the longer sides of the rectangular sheet.

8. The dual-frequency microwave directional antenna sensor according to claim 7, characterized in that: Each first microwave directional antenna (1) and second microwave directional antenna (2) are respectively arranged horizontally, the length directions of the two first microwave directional antennas (1) are parallel, and the length directions of the two second microwave directional antennas (2) are parallel.

9. The dual-frequency microwave directional antenna sensor according to claim 1, characterized in that: A first shielding cover (10) is installed outside the tube body (3) above the annular disk (9), and a second shielding cover (11) is installed outside the tube body (3) below the annular disk (9). The first shielding cover (10) is used to shield the influence of interference signals on the first microwave directional antenna (1), and the second shielding cover (11) is used to shield the influence of interference signals on the second microwave directional antenna (2).

10. Use of the dual-frequency microwave directional antenna sensor according to any one of claims 1 to 9 in detecting the water content in an oil-water mixture.

Images