A flow measurement device and method for a variable cross-section channel

Abstract

The present invention discloses a flow measurement device for a variable cross-section channel, comprising: a measurement module (1) for detecting flow information; a pressure sensor (2) for detecting pressure information; a control circuit (3) connecting the measurement module (1) and the pressure sensor (2) and for controlling the measurement module (1) to perform flow measurement according to the pressure information, and sending the flow information to a ground system via a communication cable (4); wherein the measurement module (1) comprises a switch valve plate (11). The flow measurement device for a variable cross-section channel provided by the present invention has the advantages of strong anti-fouling ability, large range ratio and adaptability to various well conditions.

Description

Technical Field

[0001] The invention belongs to the technical field of fluid measurement, and in particular relates to a flow measurement device and method for a variable cross-section channel. Background Art

[0002] With the continuous development of oil and gas fields, the pressure and oil content of the oil layer are constantly decreasing, and the output of oil wells is also continuously decreasing. In order to make up for the formation deficit caused by crude oil extraction, increase crude oil production and estimate the remaining oil reservoir content, it is necessary to inject water into the oil layer. Oil field water injection is an important means to replenish energy to the formation, maintain formation pressure, increase oil field recovery rate and maintain stable and high production of oil fields during oil field development. During the water injection process, it is necessary to accurately control the water injection volume and oil layer output of each layer, so that the oil layer situation can be effectively estimated, thereby achieving the purpose of increasing oil production.

[0003] At present, the commonly used flow measurement methods in the oil and gas field include orifice flow measurement, electromagnetic flow measurement, vortex flow measurement, ultrasonic flow measurement and volumetric flow measurement.

[0004] However, the orifice flow measurement method has a relatively small range and is greatly affected by electronic components; the electromagnetic flow measurement method has high requirements for well conditions and poor anti-pollution performance; the vortex flow measurement method has relatively high requirements for well conditions and liquid flow rate; the ultrasonic flow measurement method has high requirements for well conditions and poor anti-pollution performance; the volumetric flow measurement method requires large equipment size and is generally only suitable for ground equipment. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a flow measurement device and method for a variable cross-section channel.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] A flow measurement device for a variable cross-section channel, comprising:

[0008] A flow adjustment module, wherein a flow adjustment member is disposed inside the module, and the flow adjustment member is used to adjust the cross-sectional area of ​​the fluid flowing through the flow adjustment member;

[0009] A pressure measurement module, used to detect the pressure value of the fluid outside the flow measurement device;

[0010] A control module connected to the pressure measuring module and the flow regulating module, and configured to control the flow regulating member to stop regulating the cross-sectional area when it is detected that the pressure value of the external fluid is consistent with a preset pressure value;

[0011] The flow measurement module is used to obtain the current fluid cross-sectional area and the pressure difference on both sides of the flow adjustment component corresponding to the current fluid cross-sectional area when the flow adjustment component stops adjusting, and obtain the flow value according to the current fluid cross-sectional area and the pressure difference.

[0012] In one embodiment of the present invention, the flow adjustment module further includes a flow passage for installing the flow adjustment member.

[0013] In one embodiment of the present invention, the flow adjustment member includes a movable valve plate and a fixed valve plate that fit each other; and at least one flow hole is provided on the fixed valve plate.

[0014] In one embodiment of the present invention, the flow adjustment module further includes a driving mechanism, which is connected to the movable valve plate and is used to control the movement of the movable valve plate to adjust the cross-sectional area of ​​the fluid flowing through the flow channel.

[0015] In one embodiment of the present invention, the flow measurement module includes a pressure difference detector and a processor, the pressure difference detector is connected to the processor and is used to detect the pressure difference on both sides of the flow adjustment component corresponding to the current fluid cross-sectional area; the processor is used to obtain the current fluid cross-sectional area.

[0016] In one embodiment of the present invention, a communication module is further included, which connects the pressure measurement module, the control module and the flow measurement module and is used to send the external fluid pressure value to the control module and send the flow value to the ground equipment.

[0017] A flow measurement method for a variable cross-section channel comprises the following steps:

[0018] Adjust the cross-sectional area of ​​the flow passage to the maximum;

[0019] Detect the external fluid pressure value of the instrument;

[0020] adjusting the cross-sectional area of ​​the flow passage to a fixed value according to the pressure value of the fluid outside the instrument;

[0021] Obtain traffic information and upload it to the ground system.

[0022] In one embodiment of the present invention, adjusting the area of ​​the cross-section of the flow channel according to the pressure value of the fluid outside the instrument includes:

[0023] Real-time detection of the pressure value of the fluid outside the instrument and adjustment of the cross-sectional area of ​​the flow channel;

[0024] When it is detected that the external fluid pressure value is consistent with the preset pressure value, the adjustment of the cross-sectional area of ​​the flow passage is stopped.

[0025] In one embodiment of the present invention, the acquiring of flow information and uploading to a ground system includes:

[0026] Obtain the current flow channel cross-sectional area and the corresponding pressure difference before and after the flow channel cross-sectional area;

[0027] Obtaining current flow information according to the cross-sectional area of ​​the flow passage and the pressure difference;

[0028] The flow information is read and uploaded to the ground equipment.

[0029] Beneficial effects of the present invention:

[0030] 1. The flow measurement device of the variable cross-section channel provided by the present invention expands the range ratio of the entire instrument by expanding and superimposing multiple cross-sections, and can meet the measurement requirements of a large range ratio;

[0031] 2. The flow measurement device of the variable cross-section channel provided by the present invention uses moving parts to adjust the cross-sectional area of ​​the flow channel. Compared with the stationary parts, the moving parts are less likely to scale, deposit impurities and become blocked, and have good anti-fouling performance;

[0032] 3. The flow measurement device of the variable cross-section channel provided by the present invention has a simple structure and can meet the use requirements of different well conditions, especially the well conditions under different medium pressures and other conditions;

[0033] 4. The flow measurement device and method for the variable cross-section channel provided by the present invention have better control performance, and can make the instrument measurement and control more effective and accurate.

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of a flow measurement device for a variable cross-section channel provided by an embodiment of the present invention;

[0036] Figure 2 It is a schematic structural diagram of another flow measurement device for a variable cross-section channel provided by an embodiment of the present invention;

[0037] Figure 3 is a schematic diagram of the structure of a flow adjustment member provided by an embodiment of the present invention;

[0038] Figure 4 It is a schematic diagram of the structure of a flow adjustment module and a flow measurement module provided in an embodiment of the present invention;

[0039] Figure 5 is a schematic diagram of energy change of a fluid passing through a cross section provided by an embodiment of the present invention;

[0040] Figure 6 is a schematic diagram of flow rate changes of a fluid passing through different cross sections provided by an embodiment of the present invention;

[0041] Figure 7 1 is a graph of multiple cross-sectional characteristic curves provided by an embodiment of the present invention.

[0042] Description of the drawings: 1-flow adjustment module, 2-pressure measurement module, 3-control module, 4-flow measurement module, 5-communication module, 11-flow adjustment component, 12-flow channel, 13-driving mechanism, 41-differential pressure detector, 111-moving valve plate, 112-fixed valve plate. DETAILED DESCRIPTION

[0043] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0044] Embodiment 1

[0045] See also Figure 1 , Figure 1 1 is a schematic structural diagram of a flow measurement device for a variable cross-section channel provided by an embodiment of the present invention, comprising:

[0046] A flow adjustment module 1 is provided with a flow adjustment member 11 inside thereof, and the flow adjustment member 11 is used to adjust the cross-sectional area of ​​the fluid flowing through the flow adjustment member 11;

[0047] A pressure measuring module 2, used to detect the pressure value of the fluid outside the flow measuring device;

[0048] A control module 3, connected to the pressure measuring module 2 and the flow regulating module 1, for controlling the flow regulating member 11 to stop regulating the cross-sectional area when it is detected that the pressure value of the external fluid is consistent with the initial pressure value;

[0049] The flow measurement module 4 is used to obtain the current fluid cross-sectional area and the pressure difference on the side of the flow adjustment component 11 corresponding to the current fluid cross-sectional area when the flow adjustment component 11 stops adjusting, and obtain the flow value according to the current fluid cross-sectional area and the pressure difference.

[0050] In this embodiment, the flow adjustment module 1, under the control of the control module 3, adjusts the cross-sectional area of ​​the flow passage according to the external fluid pressure value measured by the pressure measurement module 2. The pressure measurement module 2 mainly measures the total pressure of the internal flow passage of the measuring device and the total pressure outside the measuring device, and the external total pressure is consistent with the internal pressure of the instrument under test.

[0051] The control module 3 is a circuit software integration for information exchange between the instrument and the ground. It is used to read the internal and external pressure information of the instrument measured by the pressure measurement module 2, and at the same time control the flow measurement module 4 to measure and calculate the flow, and read the measurement results and upload them to the ground system.

[0052] See also Figure 2 , Figure 2 It is a schematic structural diagram of another flow measurement device for a variable cross-section channel provided by an embodiment of the present invention;

[0053] In this embodiment, the flow adjustment module 1 further includes a flow passage 12 for installing the flow adjustment member 11 .

[0054] During measurement, the measuring device is placed inside the instrument to be measured. The liquid flows from the internal channel of the instrument through the flow channel 12 and the flow adjustment module 1, flows out of the measuring device, then flows into the instrument to be measured, and finally flows into the formation.

[0055] In this embodiment, the flow adjustment member 11 includes a movable valve plate 111 and a fixed valve plate 112 which are attached to each other; and at least one flow hole is provided on the fixed valve plate 112 .

[0056] See also Figure 3 , Figure 3 is a schematic diagram of the structure of a flow adjustment member provided by an embodiment of the present invention;

[0057] In this embodiment, the flow adjustment member is designed as a switch valve plate, wherein the moving valve plate 111 and the fixed valve plate 112 are provided with flow holes of the same shape and size. When the instrument is measuring, the switch valve plate 11 needs to be opened to the maximum, that is, fully open. At this time, the flow holes of the moving valve plate 111 and the fixed valve plate 112 completely overlap, so that the cross-sectional area changes from large to small, which is conducive to the regulation of the measurement process.

[0058] See also Figure 4 , Figure 4 It is a schematic diagram of the structure of a flow adjustment module and a flow measurement module provided in an embodiment of the present invention.

[0059] In this embodiment, the flow adjustment module 1 further includes a driving mechanism 13 , which is connected to the movable valve plate 111 and is used to control the movement of the movable valve plate 111 to adjust the cross-sectional area of ​​the fluid flowing through the flow channel 12 .

[0060] In this embodiment, the control module 3 controls the driving mechanism 13 to drive the movable valve plate 111 to generate relative displacement with the fixed valve plate 112, thereby changing the flow cross section between the movable valve plate 111 and the fixed valve plate 112, thereby changing the flow characteristics of the flow channel.

[0061] In this embodiment, the flow measurement module 4 includes a pressure difference detector 41 and a processor. The pressure difference detector 41 is connected to the processor and is used to detect the pressure difference on both sides of the flow adjustment component 11 corresponding to the current fluid cross-sectional area; the processor is used to obtain the current fluid cross-sectional area and calculate the flow value.

[0062] In this embodiment, the processor obtains the cross-sectional area by measuring the relative phase angle of the two valve plates and combining the inner and outer diameters of the flow passage of the valve plates.

[0063] In this embodiment, the flow measurement device also includes a communication module 5, which connects the pressure measurement module 2, the control module 3 and the flow measurement module 4, and is used to send the external fluid pressure value to the control module 3, and send the flow value to the ground equipment.

[0064] In this embodiment, the communication module 5 is designed as a communication cable to exchange information with the ground and control downhole equipment.

[0065] In this embodiment, the differential pressure detector 41 is first installed into the flow measurement module 4, and then the movable valve plate 111 and the fixed valve plate 112 are installed into the flow channel 12, and the flow channel 12 is connected to the flow adjustment module 1 and the driving mechanism 13. Then, the flow measurement module 4 is connected to the flow channel 12, and then the components are installed into the instrument cavity. Finally, the control module 3 and the communication module 5 are connected, and the pressure measurement module 2 and the control module 3 are installed into the instrument cavity.

[0066] The flow measurement device provided by the present invention adopts a sampling measurement method, and only requires a sampling pipeline with a very small structural size to achieve flow measurement of a large flow channel, which makes the instrument structure simple and can meet the use requirements of different well conditions.

[0067] The present invention uses moving parts to adjust the cross-sectional area of ​​the flow channel. Compared with stationary parts, moving parts are less likely to scale, deposit impurities and clog, and have good anti-fouling performance. In addition, the present invention expands the range ratio of the entire device by expanding and superimposing multiple different flow cross sections, which can meet the measurement requirements of a large range ratio and increase the scope of application of the instrument.

[0068] In this embodiment, the differential pressure detector 41 in the flow measurement module 1 measures the pressure difference before and after the switch valve plate 11, and the data processor obtains the current flow value passing through the flow channel based on the measured pressure difference and the current state of the switch valve plate 11, that is, the flow cross-sectional area.

[0069] Specifically, the measuring device is placed inside the instrument to be measured. First, the valve plate is opened to the maximum, and the internal and external pressures of the instrument are detected. At this time, the internal pressure of the device is Pn, that is, the nominal pressure, and the external pressure is Pw, which is used as the initial pressure value; then the injection pressure is increased, and then the control module 3 controls the driving mechanism 13 to drive the valve plate 111 to close. At this time, when the valve plate is closed, the external pressure of the measuring device is reduced. When it is detected that the external pressure value of the measuring device is consistent with the initial pressure value Pw, the driving mechanism 13 stops working. At this time, the flow through the flow channel 12 is the same as the flow through the instrument to be measured. Then the flow measurement module 4 reads the pressure difference before and after the valve plate, and then reads the state value of the valve plate, that is, the flow cross-sectional area, and obtains the current flow value through the built-in algorithm in the data processor. After the control module 3 reads the obtained flow, it returns it to the ground through the communication cable 5.

[0070] In this embodiment, the pressure measurement module 2, the control module 3 and the processor use high-precision, high-reliability devices and integrated circuits, so that the instrument measurement and control become more accurate and more effective.

[0071] The present invention also provides a flow measurement method for a variable cross-section channel, which is implemented based on the following principles:

[0072] After a fluid passes through a cross section, it will produce an energy loss, that is, kinetic energy loss. For incompressible fluids, the energy loss, that is, pressure loss, is manifested as a change in pressure before and after the cross section. By measuring this differential pressure, the flow rate of the fluid passing through this cross section can be obtained. When the cross section remains unchanged, the relationship characteristics between the flow rate and pressure loss of the fluid remain unchanged. In this way, after obtaining its relationship characteristics, the flow rate can be obtained through the pressure loss. Under the same pressure loss condition, when the cross section changes, the relationship characteristics will change accordingly. This change law may be linear or nonlinear. By obtaining the value of the relationship characteristics, the corresponding flow value can be obtained. See Figure 5 , Figure 5 This is a schematic diagram of the energy change of a fluid passing through a cross section provided by an embodiment of the present invention; in the figure, P1 is the pressure in front of the cross section; P2 is the pressure behind the cross section; and Q is the flow rate through the cross section. When an incompressible fluid flows through a cross section, there will be a pressure gradient before and after the cross section, where the pressure P1 in front of the cross section is greater than the pressure P2 behind the cross section.

[0073] When the area, shape, etc. of a cross section changes, the flow rate through the cross section will change if the pressure difference of the incompressible liquid before and after the cross section remains unchanged. Figure 6 , Figure 6It is a schematic diagram of the flow change of the fluid through different cross-sections provided by an embodiment of the present invention; in the figure, P1 is the pressure before the cross-section, P2, P2`, and P2`` are the pressures after the cross-section; A, A`, and A`` are three cross-sections with different areas, and Q2, Q2`, and Q2`` are the flow rates through the corresponding three cross-sections. For example, under the condition of equal pressure P1 before the cross-section and pressure P2 after the cross-section and P1>P2=P2`=P2``, when the cross-sectional area changes A>A`>A``, and the pressure difference before and after the cross-section is equal P1>P2=P2`=P2``, after the incompressible fluid flows through the cross-section, the flow rate before and after the cross-section changes to Q2>Q2`>Q2``.

[0074] By obtaining the pressure difference before and after the current section and the area of ​​the section, the flow rate through the section can be obtained. When the area of ​​the section and the pressure difference before and after the section change, the flow rate through the section also changes. In this way, the corresponding flow value can be obtained by obtaining the values ​​of the two variables related to the section through relevant equipment and methods. In this way, by reasonably changing the section, the flow ranges of each section can be superimposed, thereby obtaining a flow measurement range with a larger range ratio.

[0075] The present invention provides a flow measurement method for a variable cross-section channel, which mainly comprises the following steps:

[0076] Adjust the cross-sectional area of ​​the flow channel to the maximum, and detect the pressure value of the fluid outside the instrument to obtain the initial pressure value;

[0077] Increase the injection pressure and adjust the cross-sectional area of ​​the flow channel to change the external fluid pressure value;

[0078] After the injection pressure is increased, the external fluid pressure value will increase. According to the external fluid pressure value, the cross-sectional area of ​​the flow channel is adjusted to a fixed value;

[0079] In this embodiment, the pressure value of the fluid outside the measuring device needs to be detected in real time and compared with the external initial pressure value obtained by the previous measuring device, and the cross-sectional area of ​​the flow channel is adjusted at the same time;

[0080] When the valve disc is adjusted to change the area of ​​the flow passage, the external fluid pressure value will become smaller. When it is detected that the external fluid pressure value is reduced to the same value as the external pressure value obtained when the valve disc is not changed in the previous period, that is, the initial pressure value, the valve disc stops, that is, stops adjusting the area of ​​the cross section of the flow passage, and then keeps the area of ​​the cross section of the flow passage unchanged and starts measuring.

[0081] In this embodiment, the area of ​​the cross-section of the flow channel is controlled by the control module to control the driving mechanism to adjust the flow adjustment member. The internal and external pressures of the measuring device are measured by the internal pressure sensor and the external pressure sensor of the pressure detection module. The control module reads the measurement information of the pressure measurement module. When the control module detects that the external pressure of the measuring device is consistent with the initial external pressure obtained by the previous detection, the driving mechanism stops working and the area of ​​the cross-section of the flow channel remains unchanged. This can ensure that the flow rate through the flow channel is the same as the flow rate passing through the instrument in the previous period.

[0082] Obtain traffic information and upload it to the ground system.

[0083] In this embodiment, the differential pressure detector detects the pressure difference information before and after the cross section of the flow channel. At the same time, the data processor obtains the pressure difference information and the cross-sectional area information of the flow channel, and then calculates the flow rate.

[0084] In this embodiment, it is necessary to first draw different characteristic curves for multiple cross sections according to the flow characteristics of the cross section of the flow passage and save them in the processor. Figure 7 , Figure 7 1 is a diagram of multiple cross-sectional characteristic curves provided by an embodiment of the present invention, in which Q represents flow rate and ΔP represents the pressure difference before and after the valve plate M. Figure 7 It can be seen that the flow range of a single section is Q 11 ~Q 12 , ...Q j1 ~Q j2 , ...Q e1 ~Q e2 , but by combining and optimizing the flow ranges of multiple sections, the obtained flow range becomes Q 11 ~Q e2 This greatly broadens the flow measurement range of the equipment and improves the range ratio of the instrument.

[0085] Determine the characteristic curve N of the interface based on the obtained cross-sectional area information M , combined with the pressure difference information ΔP, the current flow information Q is obtained M .

[0086] The flow information is read and uploaded to the ground equipment.

[0087] In this embodiment, the flow information is read by the control module and transmitted to the ground system via the communication cable.

[0088] The present invention provides a flow measurement device and method with a large range ratio based on the principle of fluid pressure loss. The device and method have the advantages of strong anti-fouling ability, large range ratio and adaptability to various well conditions. Any device that uses pressure loss to measure the flow of incompressible fluid is applicable to this method.

[0089] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A flow measurement device for a variable cross-section channel, characterized in that: include: A flow adjustment module (1) is provided with a flow adjustment member (11) therein, wherein the flow adjustment member (11) is used to adjust the cross-sectional area of ​​a fluid flowing through the flow adjustment member (11); the flow adjustment module (1) also includes a flow passage (12) for installing the flow adjustment member (11); A pressure measurement module (2), used for detecting the pressure value of the fluid outside the flow measurement device; A control module (3) connected to the pressure measuring module (2) and the flow regulating module (1) and configured to control the flow regulating member (11) to stop regulating the cross-sectional area when detecting that the external fluid pressure value is consistent with the initial pressure value; A flow measurement module (4) is used to obtain the current fluid cross-sectional area and the pressure difference on both sides of the flow adjustment member (11) corresponding to the current fluid cross-sectional area when the flow adjustment member (11) stops adjusting, and obtain the flow value according to the current fluid cross-sectional area and the pressure difference; The flow measurement module (4) comprises a pressure difference detector (41) and a processor, wherein the pressure difference detector (41) is connected to the processor and is used to detect the pressure difference on both sides of the flow adjustment member (11) corresponding to the current fluid cross-sectional area; the processor is used to obtain the current fluid cross-sectional area and, based on the flow characteristics of the flow channel cross-section, draw different characteristic curves for multiple cross-sections, store them in the processor, determine the characteristic curve of the cross-section based on the obtained current fluid cross-section, and then combine the pressure difference to obtain the current flow value.

2. The flow measurement device of a variable cross-section channel according to claim 1, characterized in that: The flow adjustment member (11) comprises a movable valve plate (111) and a fixed valve plate (112) which fit each other; at least one flow hole is provided on the fixed valve plate (112).

3. The flow measurement device of a variable cross-section channel according to claim 2, characterized in that: The flow adjustment module (1) further comprises a driving mechanism (13), wherein the driving mechanism (13) is connected to the movable valve plate (111) and is used to control the movement of the movable valve plate (111) so as to adjust the cross-sectional area of ​​the fluid flowing through the flow channel (12).

4. The flow measurement device of a variable cross-section channel according to claim 1, characterized in that: It also includes a communication module (5), which is connected to the pressure measurement module (2), the control module (3) and the flow measurement module (4) and is used to send the external fluid pressure value to the control module (3) and send the flow value to the ground equipment.

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