A variable range ultrasonic flow rate testing system and testing method

Abstract

The present invention discloses a variable range ultrasonic flow test system and test method. The system includes an ultrasonic signal transceiver downhole device and a ground control terminal; the ultrasonic signal transceiver includes two first and second flow guide tubes that are movably sealed and connected, and a first ultrasonic transducer and a second ultrasonic transducer respectively arranged on the two, and also includes a screw and a transmission mechanism; the first and second flow guide tubes are respectively provided with a first and a second protrusion on the outside, the first protrusion is provided with a first through hole allowing the screw to pass through, and the second through hole of the second protrusion is provided with an internal thread matching the thread of the screw; the control terminal is used to determine the flow rate according to the echo signal collected by the ultrasonic signal transceiver, and if the flow rate is not within the predicted flow range, notify the transmission mechanism to drive the screw to rotate accordingly. The system can adapt to different flow tests by automatically changing the axial distance between the two ultrasonic transducers while keeping the diameter of the flow channel unchanged.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic flow measurement, and in particular to a variable-range ultrasonic flow test system and test method. Background Art

[0002] At present, downhole flow testing in oil fields is very common. Ultrasonic flow testing technology has gradually become the mainstream technology for downhole flow testing in oil fields with its advantages of good test stability, high test accuracy, no moving parts, and simple structure. However, as oil production in oil fields becomes more and more difficult, the formation pressure becomes smaller and smaller, and it is necessary to increase the injection of formation water. Large-displacement flow injection is becoming more and more common. However, due to the limitations of structure and principle, ultrasonic flow testing technology cannot take into account both small and large flow tests at the same time. When testing large flows with small-range ultrasonic flowmeters, its accuracy and stability will be significantly reduced. The large flow test can be adapted by increasing the diameter of the flow channel or changing the distance between the two ultrasonic sensors, but this requires changing the structure of the flowmeter and redesigning it. For downhole permanent instruments, it is necessary to re-construct the entire pipe string and replace the large-displacement flowmeter. This is not only time-consuming and labor-intensive, but also greatly increases the cost of the oil field. Summary of the invention

[0003] In order to at least partially solve the technical problems existing in the prior art, the inventors have made the present invention, and through a specific implementation method, provide a variable-range ultrasonic flow testing system and testing method, which can meet the variable-range flow testing requirements without changing the diameter of the flow channel, thereby improving the accuracy of the flow testing.

[0004] In a first aspect, an embodiment of the present invention provides a variable-range ultrasonic flow rate testing system, including a downhole ultrasonic signal transceiver and a ground control terminal;

[0005] The ultrasonic signal transceiver comprises a first flow guide tube and a second flow guide tube which are movably and hermetically connected, and a first ultrasonic transducer arranged on the first flow guide tube and a second ultrasonic transducer arranged on the second flow guide tube, wherein a cavity enclosed by the first flow guide tube and the second flow guide tube allows fluid to pass through;

[0006] The ultrasonic signal transceiver device also includes a screw and a transmission mechanism, a first protrusion is provided on the outer side of the first guide tube, a second protrusion is provided on the outer side of the second guide tube, the first protrusion is provided with a first through hole allowing the screw to pass through, the second protrusion is provided with a second through hole allowing the screw to pass through, and the second through hole is provided with an internal thread matching the thread of the screw;

[0007] The control terminal is used to determine a first flow rate based on the echo signal collected by the ultrasonic signal transceiver, and judge whether the first flow rate is within a predicted flow rate range. If not, notify the transmission mechanism to drive the screw to rotate accordingly to change the axial distance between the first ultrasonic transducer and the second ultrasonic transducer.

[0008] Optionally, an oil nut with an outer diameter matching the inner diameter of the first flow guide tube is disposed in the cavity of the first flow guide tube, and an outer thread matching the inner thread of the oil nut is disposed at the connecting end of the second flow guide tube and the first flow guide tube;

[0009] The inner wall of the connecting end of the first flow guiding tube and the second flow guiding tube is provided with at least one annular groove, and a sealing ring is provided in each groove.

[0010] Optionally, the first ultrasonic transducer is disposed in the cavity of the first flow guiding tube and is sealed and connected to the first flow guiding tube;

[0011] The second ultrasonic transducer is disposed in the cavity of the second flow guiding tube and is sealed and connected to the second flow guiding tube;

[0012] A third through hole is disposed on the side surface of the first flow guiding tube, and a fourth through hole is disposed on the side surface of the second flow guiding tube.

[0013] Optionally, the control terminal notifies the transmission mechanism to drive the screw to rotate accordingly, for:

[0014] Determine the distance according to the correspondence between the range and the distance and the predicted flow interval;

[0015] The difference between the distance and the current distance between the first ultrasonic transducer and the second ultrasonic transducer is determined, the rotation direction and rotation time of the screw are determined based on the difference, and the transmission mechanism is notified to drive the screw to rotate in the corresponding direction and time.

[0016] Optionally, the ultrasonic signal transceiver further includes a third ultrasonic transducer disposed on the first flow guide tube;

[0017] The third ultrasonic transducer is axially symmetrically arranged with respect to the first ultrasonic transducer, and is located on the same side as the second ultrasonic transducer;

[0018] The first ultrasonic transducer and the second ultrasonic transducer are used to transmit ultrasonic signals in an alternating cycle; when the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive a second echo signal, and the third ultrasonic transducer is used to receive a third echo signal; when the second ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive a first echo signal;

[0019] The control terminal is used to determine the time difference between the forward and reverse flow and the first flow rate based on the first echo signal and the second echo signal in the same test cycle; it is also used to determine the second flow rate based on the third echo signal using the frequency difference method; for the same test cycle, according to the relative size of the second flow rate and the set flow threshold and the difference amplitude between the first flow rate and the second flow rate, the solid particle content level is determined, the weights of the first flow rate and the second flow rate are determined, and the weighted average flow rate is obtained as the fluid flow rate at the corresponding time.

[0020] Optionally, the control terminal determines the solid particle content level according to the relative size of the second flow rate and the set flow rate threshold and the difference between the first flow rate and the second flow rate, determines the weights of the first flow rate and the second flow rate, and obtains a weighted average flow rate for:

[0021] When the second flow rate is not less than the set flow threshold, if the absolute difference between the first flow rate and the second flow rate is less than the first flow difference threshold, it is determined that the solid particle content is medium, and the weights of the first flow rate and the second flow rate are both determined to be 0.5; if the absolute difference between the first flow rate and the second flow rate is not less than the first flow difference threshold, and not greater than the second flow difference threshold, it is determined that the solid particle content is too little, and the first flow weight is determined to be 1, and the weight of the second flow is determined according to the first calibration result obtained in advance through experiments; if the absolute difference between the first flow rate and the second flow rate is greater than the second flow difference threshold, it is determined that the solid particle content is too much, and the second flow weight is determined to be 1, and the weight of the first flow is determined according to the second calibration result obtained in advance through experiments;

[0022] When the second flow rate is less than the flow threshold, if the absolute difference between the first flow rate and the second flow rate is not less than the first flow difference threshold, it is determined that the solid particle content is extremely small, and the first flow weight is determined to be 1, and the second flow weight is determined to be 0; if the absolute difference between the first flow rate and the second flow rate is less than the first flow difference threshold, an alarm message indicating possible equipment failure is issued.

[0023] Optionally, the traffic threshold is 1 cubic meter per day.

[0024] Optionally, the first flow difference threshold is 0.05 to 0.1 times of the current range, and the second flow difference threshold is 0.15 to 0.2 times of the current range.

[0025] Optionally, the first ultrasonic transducer and the second ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering it;

[0026] The third ultrasonic transducer is used to amplify and filter the echo signal, mix it with the excitation signal of the first ultrasonic transducer, and then collect it after low-pass filtering through a hardware circuit.

[0027] Optionally, the first, second and third ultrasonic transducers are arranged in the same plane.

[0028] In a second aspect, an embodiment of the present invention provides a variable range ultrasonic flow rate testing method, comprising:

[0029] The ultrasonic signal transceiver of any of the above variable-range ultrasonic flow test systems is lowered into the target position of the oil pipe of the target water injection well, and the flow rate of the fluid at the target position in each time period is obtained based on the output data of its control terminal.

[0030] Optionally, obtaining the flow rate of the fluid at the target position in each time period further includes:

[0031] The solid particle content level of the fluid at the target location at each time period is determined.

[0032] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0033] (1) The variable-range ultrasonic flow test system provided in the embodiment of the present invention replaces the traditional whole flow guide tube with two flow guide tubes that are movably sealed and connected. The control terminal automatically controls the axial distance between the two ultrasonic transducers through a transmission mechanism to adjust the appropriate range. Under the condition that the diameter of the flow channel remains unchanged, it can adapt to different flow tests and improve the test accuracy.

[0034] (2) The variable-range ultrasonic flow test system provided by the embodiment of the present invention has a first ultrasonic transducer and a second ultrasonic transducer arranged at a certain axial distance, which are used to transmit ultrasonic signals alternately and cyclically. The first ultrasonic transducer and the third ultrasonic transducer are arranged axially symmetrically, realizing multi-channel downhole flow test, and can determine the first flow by using the time difference method and the second flow by using the frequency difference method; for the same test cycle, the control terminal determines the solid particle content level according to the relative size of the second flow and the set flow threshold and the phase difference between the first flow and the second flow, determines the weight of the first flow and the second flow, and obtains the weighted average flow as the fluid flow at the corresponding time. The system effectively improves the adaptability of ultrasonic measurement to the purity of the fluid medium, and ensures the accuracy and reliability of downhole flow test.

[0035] (3) The variable-range ultrasonic flow rate testing system provided in the embodiment of the present invention can effectively monitor the solid particle content level of the downhole injection fluid through the flow rate results tested by the time difference method and the frequency difference method, thereby preventing the problem of the downhole dispenser water channel being blocked by solid particle impurities.

[0036] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0037] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0039] Figure 1 It is a schematic diagram of the structure of a downhole ultrasonic signal transceiver of a variable-range ultrasonic flow rate testing system in an embodiment of the present invention;

[0040] Figure 2 It is a structural schematic diagram of the downhole ultrasonic signal transceiver device after the second flow guide tube is displaced by the rotation of the screw in an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0042] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0043] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0044] In the description of the present invention, it should be noted that the terms "include", "including", "have", "contain" and the like are open terms, meaning including but not limited to.

[0045] In order to solve the problem that the ultrasonic flow test device has a relatively small range and cannot meet the application scenario of wide-range testing, an embodiment of the present invention provides a variable-range ultrasonic flow test system and a test method.

[0046] Embodiment 1

[0047] Embodiment 1 of the present invention provides a variable-range ultrasonic flow rate testing system, including a downhole ultrasonic signal transceiver and a ground control terminal.

[0048] Ultrasonic signal transceiver, see Figure 1 and Figure 2 As shown, it includes a first flow guide tube 1 and a second flow guide tube 2 that are movably sealed and connected, a first ultrasonic transducer 3 arranged on the first flow guide tube 1, and a second ultrasonic transducer 4 arranged on the second flow guide tube 2. The cavity surrounded by the first flow guide tube 1 and the second flow guide tube 2 allows fluid to pass through.

[0049] Specifically, the movable sealing connection between the first flow guide tube 1 and the second flow guide tube 2 may be achieved in the following manner:

[0050] (1) Removable connection

[0051] An oil nut 8 whose outer diameter matches its inner diameter is arranged in the cavity of the first flow guide pipe 1 , and an outer thread matching the inner thread of the oil nut 8 is arranged at the end of the connection between the second flow guide pipe 2 and the first flow guide pipe 1 .

[0052] Furthermore, after the second flow guide pipe 2 is fixedly connected to the oil nut 8 , the outer diameter of the end not connected to the oil nut is consistent with the outer diameter of the oil nut 8 .

[0053] (2) Sealed connection

[0054] The inner wall of the connecting end of the first flow guiding pipe 1 and the second flow guiding pipe 2 is provided with at least one annular groove, and a sealing ring 9 is provided in each groove.

[0055] The ultrasonic signal transceiver device also includes a screw 5 and a transmission mechanism (not shown in the figure), a first protrusion 6 is provided on the outside of the first guide tube 1, and a second protrusion 7 is provided on the outside of the second guide tube 2. The first protrusion 6 is provided with a first through hole allowing the screw 5 to pass through, and the second protrusion 7 is provided with a second through hole allowing the screw 5 to pass through, and the second through hole is provided with an internal thread matching the thread of the screw.

[0056] The control terminal is used to determine the first flow rate based on the echo signal collected by the ultrasonic signal transceiver, and judge whether the first flow rate is within the predicted flow rate range. If not, the transmission mechanism is notified to drive the screw to rotate accordingly to change the axial distance between the first ultrasonic transducer and the second ultrasonic transducer, so as to achieve a change in the range of the test system to match it with the predicted flow rate range, thereby performing accurate flow measurement.

[0057] Furthermore, the screw rod 5 includes two integrally formed sections, the section passing through the second through hole 7 is provided with external threads on the outside, and the section passing through the first through hole 6 is not provided with external threads. A bearing is provided between the screw rod 5 and the first through hole 6.

[0058] When the transmission mechanism controls the screw to rotate, the second flow guide tube 2 is displaced, driving the change in the position of the second ultrasonic transducer, thereby changing the axial distance between the first ultrasonic transducer and the second ultrasonic transducer, thereby changing the system range. Figure 2 , which is a schematic diagram of the ultrasonic signal transceiver after the second flow guiding tube 2 moves toward the first flow guiding tube 1 .

[0059] The variable-range ultrasonic flow testing system provided in the first embodiment of the present invention replaces the traditional whole flow guide tube with two flow guide tubes that are movably sealed and connected. The control terminal automatically controls the axial distance between the two ultrasonic transducers through a transmission mechanism to adjust the appropriate range. Under the condition that the diameter of the flow channel remains unchanged, it can adapt to different flow tests and improve the test accuracy.

[0060] In some embodiments, see Figure 1 and Figure 2 As shown, the first ultrasonic transducer 3 is disposed in the cavity of the first flow conduit 1 and is sealed and connected to the first flow conduit 1; the second ultrasonic transducer 4 is disposed in the cavity of the second flow conduit 2 and is sealed and connected to the second flow conduit 2. The side of the first flow conduit 1 is provided with a third through hole 10 for allowing fluid to pass through, and the side of the second flow conduit 2 is provided with a fourth through hole 11 for allowing fluid to pass through. At this time, the control terminal notifies the transmission mechanism to drive the screw to rotate accordingly, which is used to:

[0061] The distance is determined according to the correspondence between the range and the distance and the predicted flow interval; the difference between the distance and the current distance between the first ultrasonic transducer and the second ultrasonic transducer is determined, and the rotation direction and rotation time of the screw are determined based on the difference, and the transmission mechanism is notified to drive the screw to rotate in the corresponding direction and time. Among them, when the screw speed is constant, the rotation time and the moving distance are in a one-to-one correspondence.

[0062] Optionally, the ultrasonic transducer may be arranged on the side of the guide tube instead of inside the cavity of the guide tube. In this case, the determination of the screw rotation time is relatively complicated. In addition to considering the rotation speed, it is also necessary to combine the change in the angle between the two ultrasonic sensors to comprehensively determine the required screw movement distance.

[0063] Embodiment 2

[0064] The second embodiment of the present invention provides an ultrasonic flow rate testing system with a variable range, which is a further improvement on the ultrasonic flow rate testing system in the first embodiment in which the ultrasonic transducer is arranged on the side of the flow guide pipe.

[0065] The ultrasonic signal transceiver device in this embodiment further includes a third ultrasonic transducer disposed on the first flow guide tube; the third ultrasonic transducer is disposed axially symmetrically with the first ultrasonic transducer and is located on the same side as the second ultrasonic transducer. That is, in the cross-sectional view of the ultrasonic signal transceiver device, the third ultrasonic transducer is located on the same side as the second ultrasonic transducer, and the first ultrasonic transducer is located on the other side.

[0066] The first ultrasonic transducer and the second ultrasonic transducer are used to transmit ultrasonic signals in an alternating cycle; when the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive a second echo signal, and the third ultrasonic transducer is used to receive a third echo signal; when the second ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive the first echo signal.

[0067] Furthermore, the first, second and third ultrasonic transducers are arranged in the same plane and fixedly installed on both sides of the test flow guide tube by contact installation. Each ultrasonic transducer is provided with an acoustic wedge.

[0068] Taking the first ultrasonic transducer located upstream and the second ultrasonic transducer located downstream as an example, the specific working principles of the three ultrasonic transducers are as follows:

[0069] The first ultrasonic transducer is driven to emit an ultrasonic signal of a certain frequency, and the two ultrasonic transducers on the other side respectively receive the echo waveform signal and convert it into a voltage signal recognizable by the circuit, wherein the second ultrasonic transducer obtains a downstream echo signal, and the third ultrasonic transducer at the axially symmetrical position obtains a reflected or scattered echo signal; the second ultrasonic transducer is driven to emit an ultrasonic wave, and the first ultrasonic transducer on the other side receives the echo waveform signal to obtain an upstream echo signal.

[0070] The first ultrasonic transducer and the second ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering it through the hardware circuit; the third ultrasonic transducer is used to amplify and filter the echo signal through the hardware circuit, mix it with the excitation signal of the first ultrasonic transducer, and then collect it after low-pass filtering through the acquisition circuit.

[0071] The control terminal is used to determine the time difference between the forward and reverse flow and the first flow rate based on the first echo signal and the second echo signal within the same test cycle; it is also used to determine the second flow rate based on the third echo signal using the frequency difference method; for the same test cycle, according to the relative size of the second flow rate and the set flow threshold and the difference amplitude between the first flow rate and the second flow rate, the solid particle content level is determined, the weights of the first flow rate and the second flow rate are determined, and the weighted average flow rate is obtained as the fluid flow rate at the corresponding time.

[0072] Specifically, the following steps may be included:

[0073] 1. Perform filtering and noise reduction preprocessing on the upstream and downstream echo signals (the first echo signal and the second echo signal) in the same period, and use the adaptive threshold method to calculate the upstream and downstream time and the upstream and downstream time difference of the filtered signals, and then calculate the first flow rate Q1 of the fluid.

[0074] The original echo signals of both upstream and downstream are processed by sliding window mean filtering, with a sliding window size of N. The adaptive threshold method is used to find the first broadcast position of the echo signal after filtering, and the position of the mean value point after the first broadcast position is used as the characteristic point position for calculating the upstream and downstream transmission time of the sound wave, so as to calculate the upstream and downstream time. , Time difference between upstream and downstream , through the upstream and downstream time , , upstream and downstream time difference The first flow rate Q1 is obtained by calculating the installation structure parameters of the transducer guide tube.

[0075] 2. Perform filtering and noise reduction preprocessing on the obtained reflected and / or scattered echo signal (third echo signal), convert the filtered signal from the time domain to the frequency domain, obtain the frequency difference by analyzing its spectrum, and obtain the second flow Q2 by calculating the frequency difference.

[0076] The collected third echo signal, i.e. the frequency shift signal, is subjected to FIR filtering, noise reduction and smoothing processing, and the filtered signal is sampled to obtain the resampled signal, and a fast FFT frequency domain analysis is performed to obtain the final frequency difference. The second flow rate Q2 is calculated by combining the sound wedge sound velocity, the transducer installation structure parameters and the test guide tube structure.

[0077] 3. For the same test cycle, the solid particle content level is determined according to the relative size of the second flow rate and the set flow threshold value and the difference between the first flow rate and the second flow rate, and the weights of the first flow rate and the second flow rate are determined to obtain the weighted average flow rate as the fluid flow rate at the corresponding time.

[0078] The implementation of step 3 above, as shown in Table 1, includes the following situations:

[0079] Table 1 Statistics of solid particle content levels

[0080] (1) When the second flow rate Q2 is not less than the set flow rate threshold S1

[0081] ① If the absolute difference between the first flow rate Q1 and the second flow rate Q2 is less than the first flow rate difference threshold K1, it is determined that the solid particle content is medium, and the weight W1 of the first flow rate and the weight W2 of the second flow rate are both determined to be 0.5.

[0082] First, the second flow rate Q2 is not small enough, indicating that there are certain solid particles in the fluid. At this time, if It is small enough, indicating that the flow rates measured by the time difference method and the frequency difference method are similar, and the solid particle content is determined to be medium, so the weights of the two flow rates are determined to be 0.5.

[0083] ② If the absolute difference between the first flow rate and the second flow rate is not less than the first flow rate difference threshold K1 and not greater than the second flow rate difference threshold K2, it is determined that the solid particle content is too little, and the first flow rate weight W1 is determined to be 1. The second flow rate weight W2 is determined based on the first calibration result obtained in advance through experiments.

[0084] The second flow rate Q2 is not small enough, indicating that there are certain solid particles in the fluid. At this time, if It is neither small enough nor large enough, and it is determined that the solid particle content is too little. The flow rate measured by the time difference method is already close to the actual flow rate, but it is affected by certain solid particles. Therefore, the flow rate measured by the time difference method needs to be corrected using the flow rate measured by the frequency difference method.

[0085] ③ If the absolute difference between the first flow rate and the second flow rate is greater than the second flow rate difference threshold K2, it is determined that the solid particle content is too high, and the second flow rate weight W2 is determined to be 1. The weight W1 of the first flow rate is determined according to the second calibration result obtained in advance through experiments.

[0086] The second flow rate Q2 is not small enough, indicating that there are certain solid particles in the fluid. At this time, if It is large enough to determine that the solid particle content is too high. The flow rate measured by the frequency difference method is closer to the actual flow rate. Therefore, the flow rate measured by the frequency difference method needs to be corrected using the flow rate measured by the time difference method.

[0087] (2) When the second flow rate is less than the flow threshold S1

[0088] ① If the absolute difference between the first flow rate Q1 and the second flow rate Q2 is not less than a flow difference threshold K1, it is determined that the solid particle content is very small, and the first flow rate weight W1 is determined to be 1, and the second flow rate weight W2 is determined to be 0.

[0089] First, if the second flow rate Q2 is small enough, it means that there are fewer solid particles in the fluid, and the flow rate measured by the frequency difference method will be relatively small in theory. It is not too small, which means that the flow rates measured by the time difference method and the frequency difference method are not so close. The flow rate measured by the time difference method is more accurate, and the solid particle content is determined to be extremely small. The first flow weight W1 is determined to be 1, and the second flow weight W2 is determined to be 0.

[0090] ② If the absolute difference between the first flow rate Q1 and the second flow rate Q2 is less than the first flow difference threshold K1, an alarm message indicating a possible equipment failure is issued.

[0091] First, if the second flow rate Q2 is small enough, it means that there are fewer solid particles in the fluid, and the flow rate measured by the frequency difference method will be relatively small in theory. It is small enough, which means that the flow rates measured by the time difference method and the frequency difference method are similar. That is, the flow rate measured by the time difference method is also small, which is obviously inconsistent with the reality, indicating the possibility of machine failure.

[0092] In some embodiments, the first flow difference threshold is determined to be 0.05 to 0.1 times the current range of the system, and the second flow difference threshold is determined to be 0.15 to 0.2 times the current range of the system; the flow threshold is determined to be 1 cubic meter / day.

[0093] In the variable-range ultrasonic flow test system provided by the second embodiment of the present invention, the first ultrasonic transducer and the second ultrasonic transducer are arranged at a certain axial distance, and are used to transmit ultrasonic signals alternately and cyclically. The first ultrasonic transducer and the third ultrasonic transducer are arranged axially symmetrically, realizing multi-channel downhole flow test, and can determine the first flow by the time difference method, and determine the second flow by the frequency difference method; for the same test cycle, the control terminal determines the solid particle content level according to the relative size of the second flow and the set flow threshold and the phase difference amplitude between the first flow and the second flow, and determines the weight of the first flow and the second flow, and obtains the weighted average flow as the fluid flow at the corresponding time. The system effectively improves the adaptability of ultrasonic measurement to the purity of the fluid medium, and ensures the accuracy and reliability of downhole flow test.

[0094] The variable-range ultrasonic flow testing system provided in the second embodiment of the present invention can effectively monitor the solid particle content level of the downhole injection fluid through the flow results tested by the time difference method and the frequency difference method, thereby preventing the problem of the downhole dispenser water channel being blocked by solid particle impurities.

[0095] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a variable range ultrasonic flow rate testing method, comprising:

[0096] The ultrasonic signal transceiver of any of the above variable-range ultrasonic flow test systems is lowered into the target position of the oil pipe of the target water injection well, and the flow rate of the fluid at the target position in each time period is obtained based on the output data of its control terminal.

[0097] Optionally, obtaining the flow rate of the fluid at the target position in each time period further includes:

[0098] The solid particle content level of the fluid at the target location at each time period is determined.

[0099] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0100] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that the embodiments of the claimed subject matter require more features than are clearly stated in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0101] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to represent "non-exclusive or". The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

Claims

1. A variable range ultrasonic flow test system, characterized in that: It includes a downhole ultrasonic signal transceiver and a ground control terminal; The ultrasonic signal transceiver comprises a first flow guide tube and a second flow guide tube which are movably and hermetically connected, and a first ultrasonic transducer arranged on the first flow guide tube and a second ultrasonic transducer arranged on the second flow guide tube, wherein a cavity enclosed by the first flow guide tube and the second flow guide tube allows fluid to pass through; The ultrasonic signal transceiver device also includes a screw and a transmission mechanism, a first protrusion is provided on the outer side of the first guide tube, a second protrusion is provided on the outer side of the second guide tube, the first protrusion is provided with a first through hole allowing the screw to pass through, the second protrusion is provided with a second through hole allowing the screw to pass through, and the second through hole is provided with an internal thread matching the thread of the screw; The ultrasonic signal transceiver device further includes a third ultrasonic transducer disposed on the first flow guide tube; the third ultrasonic transducer is axially symmetrically disposed with the first ultrasonic transducer and is located on the same side as the second ultrasonic transducer; the first ultrasonic transducer and the second ultrasonic transducer are used to transmit ultrasonic signals in an alternating cycle; when the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive a second echo signal, and the third ultrasonic transducer is used to receive a third echo signal; when the second ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive a first echo signal; The control terminal is used to determine the first flow rate by using the time difference method and the second flow rate by using the frequency difference method according to the echo signals collected by the ultrasonic signal transceiver within the same test cycle; determine the solid particle content level according to the relative size of the second flow rate and the set flow rate threshold and the difference between the first flow rate and the second flow rate, determine the weights of the first flow rate and the second flow rate, and obtain the weighted average flow rate as the fluid flow rate at the corresponding time; determine whether the fluid flow rate is within the predicted flow range, and if not, notify the transmission mechanism to drive the screw to rotate accordingly to change the axial distance between the first ultrasonic transducer and the second ultrasonic transducer.

2. The system according to claim 1, characterized in that An oil nut with an outer diameter matching the inner diameter thereof is arranged in the cavity of the first flow guide pipe, and an outer thread matching the inner thread of the oil nut is arranged at the connecting end of the second flow guide pipe and the first flow guide pipe; The inner wall of the connecting end of the first flow guiding tube and the second flow guiding tube is provided with at least one annular groove, and a sealing ring is provided in each groove.

3. The system according to claim 1, characterized in that The first ultrasonic transducer is disposed in the cavity of the first flow guiding tube and is sealed and connected to the first flow guiding tube; The second ultrasonic transducer is disposed in the cavity of the second flow guide tube and is sealed and connected to the second flow guide tube; A third through hole is disposed on the side surface of the first flow guiding tube, and a fourth through hole is disposed on the side surface of the second flow guiding tube.

4. The system according to claim 3, characterized in that The control terminal notifies the transmission mechanism to drive the screw to rotate accordingly, and is used to: Determine the distance according to the correspondence between the range and the distance and the predicted flow interval; The difference between the distance and the current distance between the first ultrasonic transducer and the second ultrasonic transducer is determined, the rotation direction and rotation time of the screw are determined based on the difference, and the transmission mechanism is notified to drive the screw to rotate in the corresponding direction and time.

5. The system according to claim 1, wherein: The control terminal is used to determine the forward and reverse flow time difference and the first flow rate based on the first echo signal and the second echo signal in the same test cycle; and is also used to determine the second flow rate by using the frequency difference method based on the third echo signal.

6. The system according to claim 1, wherein: The control terminal determines the solid particle content level and the weights of the first flow rate and the second flow rate according to the relative size of the second flow rate and the set flow rate threshold and the difference between the first flow rate and the second flow rate, and obtains a weighted average flow rate for: When the second flow rate is not less than the set flow threshold, if the absolute difference between the first flow rate and the second flow rate is less than the first flow difference threshold, it is determined that the solid particle content is medium, and the weights of the first flow rate and the second flow rate are both determined to be 0.5; if the absolute difference between the first flow rate and the second flow rate is not less than the first flow difference threshold, and not greater than the second flow difference threshold, it is determined that the solid particle content is too little, and the first flow weight is determined to be 1, and the weight of the second flow is determined according to the first calibration result obtained in advance through experiments; if the absolute difference between the first flow rate and the second flow rate is greater than the second flow difference threshold, it is determined that the solid particle content is too much, and the second flow weight is determined to be 1, and the weight of the first flow is determined according to the second calibration result obtained in advance through experiments; When the second flow rate is less than the flow threshold, if the absolute difference between the first flow rate and the second flow rate is not less than the first flow difference threshold, it is determined that the solid particle content is extremely small, and the first flow weight is determined to be 1, and the second flow weight is determined to be 0; if the absolute difference between the first flow rate and the second flow rate is less than the first flow difference threshold, an alarm message indicating possible equipment failure is issued.

7. The system according to claim 6, characterized in that The traffic threshold is 1 cubic meter per day.

8. The system according to claim 6, characterized in that The first flow difference threshold is 0.05 to 0.1 times of the current range, and the second flow difference threshold is 0.15 to 0.2 times of the current range.

9. The system according to claim 1, characterized in that The first ultrasonic transducer and the second ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering; The third ultrasonic transducer is used to amplify and filter the echo signal, mix it with the excitation signal of the first ultrasonic transducer, and then collect it after low-pass filtering through a hardware circuit.

10. The system according to claim 1, wherein: The first, second and third ultrasonic transducers are arranged in the same plane.

11. A variable range ultrasonic flow rate testing method, characterized in that: include: The ultrasonic signal transceiver of the variable-range ultrasonic flow test system according to any one of claims 1 to 10 is lowered into the target position of the oil pipe of the target water injection well, and the flow rate of the fluid at the target position in each time period is obtained based on the output data of its control terminal.

12. The method according to claim 11, characterized in that The step of obtaining the flow rate of the fluid at the target position in each time period further includes: The solid particle content level of the fluid at the target location at each time period is determined.

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