An annular probe measurement system for measuring gas-liquid two-phase distribution parameters in an annulus

Abstract

The application provides a ring probe measurement processing system for measuring parameters of horizontal annular air-liquid two-phase flow, which comprises a detection module arranged at a corresponding position of parallel pipelines and used for detecting voltage when liquid passes through the parallel pipelines; the detection module comprises at least one group of detection electrodes; the detection electrodes comprise an inner ring probe arranged at the center of the parallel pipelines and an outer ring probe arranged at the outer ring of the parallel pipelines; and the detection electrodes are used for detecting voltage between the inner ring probe and the outer ring probe when liquid flows through. The application sets at least one group of detection electrodes in the parallel pipelines, sets one end of the detection electrodes on the inner wall of the parallel pipelines and sets the other end of the detection electrodes at a concentric circle position of the outer ring probe in the center of the parallel pipelines, detects conductivity when liquid flows through, and calculates water content in the parallel pipelines. The outer ring probe has the same inner diameter as the parallel pipelines, which can reduce the influence of the detection electrodes on the flow shape in the parallel pipelines, so that flow shape parameters close to real working conditions are obtained.

Description

Technical Field

[0001] This invention relates to the field of real-time dynamic monitoring of oil and gas wells, and specifically to a ring probe measurement system for measuring the gas-liquid two-phase distribution parameters in annulus pipes. Background Technology

[0002] Two-phase flow (BPCF) refers to the flow phenomenon in which substances exist in both gaseous and liquid states within a parallel pipe. BPCF is widely observed in nature and various industries. Due to the uncertainty of the interactions between different phases, BPCF exhibits more complex flow and heat transfer characteristics compared to single-phase flow. Given the complex characteristics of BPCF, accurately measuring parameters such as the cavitation fraction and interfacial velocity at high water content and low flow velocity is crucial for studying the two-phase structure and variation patterns of BPCF.

[0003] Existing detection probes for parallel flow pipes, when installed after the pipe, can cause deviations in detection data due to the influence of the flow pattern within the pipe. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem of detection data deviation in the existing technology.

[0005] To achieve the above objectives, the present invention provides an annular probe measurement system for measuring the gas-liquid two-phase distribution parameters in an annular pipe, comprising: a detection module disposed at a corresponding position in a parallel pipe for detecting the voltage when liquid flows through the parallel pipe; the detection module includes at least one set of detection electrodes; the detection electrodes include an inner ring probe disposed at the center of the parallel pipe and an outer ring probe disposed on the outer ring of the parallel pipe; the detection electrodes are used to detect the voltage between the inner ring probe and the outer ring probe when liquid flows through.

[0006] To further improve detection accuracy and reduce the impact on flowing substances, the present invention has made the following further design to the scheme.

[0007] As a further design of the present invention, the outer ring probe is a ring structure, and the inner ring probe is disposed inside the outer ring probe, with the inner ring probe and the outer ring probe arranged in concentric circles.

[0008] As a further design of the present invention, the detection module also includes: an insulating fluid conductor and a support rod, wherein the insulating fluid conductor is disposed inside the parallel pipe, and the support rod passes through the parallel pipe and is fixedly connected to the insulating fluid conductor inside the parallel pipe.

[0009] As a further design of the present invention, the outer ring probe is fixed inside the parallel pipe by a rubber flange, and the inner diameter of the outer ring probe is the same as the inner diameter of the parallel pipe.

[0010] As a further design of the present invention, the support rod has a hollow structure, and a connecting wire is provided inside the support rod to electrically connect the inner ring probe to the data processing module.

[0011] As a further design of the present invention, the rubber flange has a circular insertion hole, and a connecting wire is provided inside the circular insertion hole. The outer ring probe is electrically connected to the data processing module through the connecting wire.

[0012] As a further design of the present invention, the insulating fluid conductor has a rod-shaped structure with hemispherical protrusions at both ends; the insulating fluid conductor has a protective sleeve; the protective sleeve has an insulating layer.

[0013] As a further design of the present invention, the insulating fluid has the same outer diameter as the inner ring probe.

[0014] As a further design of the present invention, the measurement system also includes a signal processing module, which is connected to the control module and is used to perform signal data processing on the conductivity value detected by the detection module.

[0015] Through the above technical solution, the present invention sets at least one set of detection electrodes in a parallel pipe, with one end of the detection electrode set on the inner wall of the parallel pipe and the other end set at the center of the parallel pipe and the concentric circle position of the outer ring probe. The water content in the parallel pipe is calculated by detecting the voltage when liquid flows through it.

[0016] The outer ring probe of this invention has the same inner diameter as the parallel pipe, which can reduce the influence of the detection electrode on the flow pattern inside the parallel pipe and obtain flow pattern parameters that are closer to the actual working conditions.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a connection block diagram of the ring probe measurement system provided in an embodiment of the present invention;

[0020] Figure 2 A circuit diagram of the signal processing circuit of the ring probe measurement system provided in an embodiment of the present invention;

[0021] Figure 3A perspective view of the detection module and parallel pipe of the ring probe measurement system provided in an embodiment of the present invention;

[0022] Figure 4 This is a cross-sectional view of the detection module of the ring probe measurement system provided in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the rubber flange of the annular probe measurement system provided in an embodiment of the present invention.

[0024] Explanation of reference numerals in the attached figures

[0025] 1-Outer ring probe, 2-Inner ring probe, 3-Insulated fluid conductor, 4-Parallel pipe, 5-Rubber flange, 6-Support rod, 7-Protective sleeve, 8-Circular socket. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below with reference to specific examples and the accompanying drawings.

[0027] This embodiment proposes a ring probe measurement system for measuring the gas-liquid two-phase distribution parameters within an annular tube, such as... Figure 1 As shown, the device includes a detection module, which is installed at the location of the parallel pipe 4 to be tested, and at a corresponding position within the parallel pipe 4, to detect the conductivity when liquid flows within the parallel pipe 4. The detection module includes at least one set of detection electrodes, and the measuring electrodes include an outer ring probe 1 and an inner ring probe 2. By cooperating with the outer ring probe 1 and the inner ring probe 2, the voltage between the outer ring probe 1 and the inner ring probe 2 is measured when liquid flows through them.

[0028] In this embodiment, the outer ring probe 1 has a circular structure and is arranged inside the parallel pipe 4 to be tested. The inner ring probe 2 can also have a circular structure. The inner ring probe 2 and the outer ring probe 1 are placed concentrically perpendicular to the flow surface of the parallel pipe 4. To ensure that the inner ring probe 2 and the outer ring probe 1 are arranged concentrically and that the inner ring probe 2 is positioned at the center of the parallel pipe 4, the inner ring probe 2 is fitted onto the insulating guide 3. A notch is provided on the parallel pipe 4 to accommodate the support rod 6. The size of the notch is just large enough to accommodate the support rod 6. The support rod 6 passes through the notch on the parallel pipe 4 and connects to the insulating guide 3 at the center of the parallel pipe 4, fixing the insulating guide 3 at the center of the parallel pipe 4, ensuring that the inner ring probe 2 can be suspended and accurately fixed at the center of the parallel pipe 4. To facilitate the connection of the inner ring probe 2 at the center of the parallel pipe 4 to the data processing module, the support rod 6 is designed as a hollow structure. The hollow interior of the support rod 6 is used to arrange connecting wires, which electrically connect the inner ring probe 2 to the data processing module. To ensure that the insulating fluid conductor 3 can be more stably fixed in the corresponding position inside the parallel pipe 4, two support rods 6 arranged in the same manner as the upper part can be installed at the lower part of the insulating fluid conductor 3.

[0029] In this embodiment, considering the influence of the insulating fluid 3 on the measurement during the inner ring probe 2 and outer ring probe 1 measurements, a protective sleeve 7 is arranged on the insulating fluid 3. The protective sleeve 7 covers the connecting wire between the inner ring probe 2 and the data processing module, eliminating the influence of the fluid on the connecting wire. To avoid the influence of the insulating fluid 3 on the measurement during the measurement of the inner ring probe 2 and outer ring probe 1, an insulating layer is coated on the outside of the protective sleeve 7 covering the insulating fluid 3. The insulating layer should avoid affecting the external position of the inner ring probe 2.

[0030] In this embodiment, to facilitate the installation of the detection module, after the insulating fluid guide 3 and the inner ring probe 2 are placed into the parallel pipe 4, the parallel pipe 4 can be fixedly connected by a rubber flange 5. Considering that the contact between the fluid and the parallel pipe 4 should be smooth and the flow pattern should be consistent with that before reaching the detection position, the inner diameter of the rubber flange 5 is set to be the same as the outer diameter of the outer ring probe 1, and the inner diameter of the outer ring probe 1 is the same as the inner diameter of the parallel pipe 4. This can largely avoid detection deviations caused by the influence of the detection module on the fluid flow pattern. By optimizing the structure of the detection electrode, the influence of the embedded sensor on the flow pattern is greatly reduced, enabling it to obtain flow pattern parameters that are closer to the actual working conditions.

[0031] In this embodiment, the structure of the rubber flange 5 is as follows: Figure 5As shown, the rubber flange 5 has at least four holes for mounting bolts, which are used to connect the rubber flange 5 and the parallel pipe 4. Circular insertion holes 8 are also provided along the radius of the rubber flange 5 disc surface. These circular insertion holes 8 are used to install connecting wires, connecting the outer ring probe 1 to the data processing module. The outer ring probe 1, in addition to its corresponding position with the inner ring probe 2, is also coated with an insulating layer.

[0032] In this embodiment, to minimize the influence of the inner ring probe 2 on the manifold, the outer diameter of the inner ring probe 2 is the same as the outer diameter of the insulating fluid conductor 3. It should be noted that after the inner ring probe 2 is fitted onto the insulating fluid conductor 3, its outer diameter is the same as the outer diameter of the insulating fluid conductor 3 with the protective sleeve 7 and the insulating layer applied. Hemispherical protrusions are provided at both ends of the insulating fluid conductor 3 to reduce its influence on the manifold. However, the ends of the insulating fluid conductor 3 are not limited to hemispherical structures; other flow guiding structures applicable here can be used to minimize the influence on the manifold.

[0033] In this embodiment, the signal processing module is connected to the detection module. Since the liquid flow rate determines the conductivity, in order to obtain the relationship between the output voltage of the data processing module and the conductivity, such as... Figure 2 As shown, firstly, assume Rm is the equivalent resistance between the inner loop probe 2 and the outer loop probe 1, VA+ and VA- are equal to the input voltage signal, and measure the current I on the electrode. m for:

[0034]

[0035] According to the characteristics of the operational amplifier, the currents flowing through Rm and Rref are equal, and the voltage difference through Rref is Vref:

[0036]

[0037] In a coaxial probe, when the amplification factor of the differential amplifier is N, it is also because:

[0038]

[0039]

[0040] G is the conductivity of the probe measurement area, σ is the conductivity of the liquid, A is the area of ​​the probe facing each other, L is the axial length of the probe, R is the radius of the outer ring probe 1, and r is the radius of the inner ring probe 2. Therefore, the output signal Vout of the data processing module can be written as:

[0041]

[0042] In a parallel probe, when the differential amplifier has a gain of N, it is because:

[0043]

[0044] G = σA / S

[0045] G is the conductivity of the probe measurement area, σ is the conductivity of the liquid, A is the area of ​​the probes facing each other, and S is the axial length between the probes. Therefore, the output signal Vout can be written as:

[0046] V out =NR ref (2V A )σA / S

[0047] When the probe and circuit are determined With R ref (2V A Since A / S is a constant, the change in the output voltage signal is theoretically linearly proportional to the change in the conductivity σ of the solution. This means the detection module exhibits high resolution and linearity with respect to the solution's conductivity.

[0048] In this embodiment, the outer ring probe 1 can be used as the excitation electrode, and the inner ring probe 2 as the measurement electrode. By applying a high voltage to the outer ring probe 1 and a low voltage to the inner ring probe 2, the conductivity between the outer ring probe 1 and the inner ring probe 2 is detected, processed by the data processing module, and sent to the computer to calculate the water fraction flowing through the parallel pipe. The conductivity is calculated using the voltage between the inner ring probe 2 and the outer ring probe 1.

[0049] The specific principle is as follows: In a horizontal gas-liquid two-phase flow, due to the influence of gravity, air flows at the top of the parallel pipe 4, while water flows at the bottom, thus causing stratification. Air is a non-conductive medium; therefore, in the static calibration of stratified flow, the response voltage of the fluid is measured. This method is suitable for high-resolution measurement of water holdup in high-water-content, low-velocity gas-liquid two-phase flows within horizontal pipes. The annular coaxial sensor designed within a 50mm pipe diameter exhibits optimal electric field distribution characteristics at an excitation frequency of 20kHz, and at high water content, its sensor phase output shows a high-resolution linear relationship with the water holdup.

[0050] The computer calculates the water content during detection in the following way. For example, the relationship between the water content Hw and the dimensionless voltage U* in stratified flow calibration can be fitted as follows:

[0051] H w =U *

[0052] According to Maxwell's theory, for a uniformly distributed spherical droplet, the relationship between the water content Hw and the dimensionless voltage U* can be expressed as:

[0053]

[0054] Where the dimensionless U* is defined as

[0055] U * =U W / U

[0056] In the formula, Uw is the voltage value when the parallel pipe 4 is filled with water, and U is the voltage value of the gas-liquid mixture inside the parallel pipe 4, that is, the voltage value between the outer ring probe 1 and the inner ring probe 2. The gas-liquid bubble flow of the oil-water mixture, in which the movement of dispersed phase bubbles is a commonly observed phase distribution, can be simulated by placing many plastic balls of known diameter into the parallel pipe 4.

[0057] In this embodiment, the ring probe measurement system is equipped with a data acquisition card and a power supply. The signal processing module amplifies, filters, and rectifies the signal. The data acquisition card converts the analog signal output by the signal processing module into a digital signal and transmits it to the computer. The acquisition frequency of the data acquisition card can be set to achieve different measurement densities. The power supply provides power to the data processing module. To further reduce the impact on the signal in the measurement system, shielded twisted-pair cables are used for the connections between the inner ring probe 2 and the data processing module, the outer ring probe 1 and the data processing module, and the data acquisition card and the data processing module.

[0058] In this embodiment, while measuring the conductivity of the liquid flowing through the parallel pipe 4 using the outer ring probe 1 and inner ring probe 2 of a set of detection electrodes, an auxiliary detection electrode is set up. The auxiliary detection electrode consists of two outer ring probes 1. By measuring the voltage between the two outer ring probes 1, a set of conductivity data is obtained. Based on the comparison between these two data and the actual liquid holding capacity, the ratios of the liquid holding capacity measured by the set of detection electrodes and the liquid holding capacity measured by the auxiliary detection electrode to the actual liquid holding capacity are obtained. Therefore, a set of detection electrodes and auxiliary detection electrodes can be set up simultaneously, including four outer ring probes 1 and two inner ring probes 2, each connected to a data processing module. This data processing module is connected to... Figure 2 The circuit structure shown is the same. Four outer ring probes 1 are horizontally distributed. When current is applied to the two middle outer ring probes 1, a voltage difference is formed between them and the corresponding inner ring probes 2. Simultaneously, a voltage difference also exists between the outer ring probes 1 closest to the applied-current probes 1. The voltage between the outer ring probes 1 and the inner ring probes 2 is measured. Based on the ratio of the detection electrode and the auxiliary detection electrode to the true liquid holding capacity, different weights are assigned to the detection electrode and the auxiliary detection electrode. Finally, the detection results of the detection electrode and the auxiliary detection electrode are combined to obtain a more accurate liquid holding capacity. In this embodiment, the liquid holding capacity measured is the water content detected in the parallel pipe 4.

[0059] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0060] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples. Within the framework of the invention, technical features of the above embodiments or different embodiments can be combined, and many other variations of different aspects of the invention exist, which are not provided in the details for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the protection scope of the invention.

Claims

1. A ring probe measurement system for measuring gas-liquid two-phase distribution parameters in an annular tube, characterized in that, include: A detection module is set at a corresponding position in the parallel pipe (4) to detect the voltage when liquid flows through the parallel pipe (4). The detection module includes at least one set of detection electrodes. The detection electrodes include an inner ring probe (2) set at the center of the parallel pipe and an outer ring probe (1) set at the outer ring of the parallel pipe. The detection electrodes are used to detect the voltage between the inner ring probe (2) and the outer ring probe (1) when liquid flows through. The outer ring probe (1) has a ring structure, and the inner ring probe (2) is set inside the outer ring probe (1). The inner ring probe (2) and the outer ring probe (1) are arranged concentrically. The detection module also includes an insulating guide (3) and a support rod (6). (3) Set inside the parallel pipe (4), the support rod (6) passes through the parallel pipe (4) and is fixedly connected to the insulating fluid (3) inside the parallel pipe. The insulating fluid (3) is a rod-shaped structure with hemispherical protrusions at both ends. The insulating fluid (3) has a protective sleeve (7) outside. The protective sleeve (7) has an insulating layer. When the inner ring probe (2) is fitted on the insulating fluid (3), it has the same outer diameter as the insulating fluid (3) fitted with the protective sleeve (7) and coated with the insulating layer. The outer ring probe (1) is fixed inside the parallel pipe (4) by a rubber flange (5). The inner diameter of the outer ring probe (1) is the same as the inner diameter of the parallel pipe (4).

2. The annular probe measurement system for measuring gas-liquid two-phase distribution parameters in an annular tube according to claim 1, characterized in that, The support rod (6) is a hollow structure, and a connecting line is provided inside the support rod (6). The connecting line electrically connects the inner ring probe (2) to the data processing module.

3. The annular probe measurement system for measuring gas-liquid two-phase distribution parameters in an annular tube according to claim 2, characterized in that, The rubber flange (5) has a circular insertion hole (8), and a connecting wire is provided inside the circular insertion hole (8). The outer ring probe (1) is electrically connected to the data processing module through the connecting wire.

4. The annular probe measurement system for measuring gas-liquid two-phase distribution parameters in an annular tube according to claim 1, characterized in that, Also includes: The signal processing module is connected to the control module and is used to process the conductivity value detected by the detection module.

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