A downhole flow rate testing system, method and device

Abstract

The present invention discloses a downhole flow testing system, method and device. The testing system includes a downhole flow testing device and a ground control terminal; the downhole flow testing device is used to collect and send to the control terminal the echo signal required to determine the first flow using the time difference method and the echo signal required to determine the second flow using the frequency difference method in each test cycle; the control terminal is used to determine the first flow and the second flow, and for the same test cycle, according to the relative size of the second flow and the set flow threshold and the difference amplitude between the first flow and the second flow, determine the solid particle content level, determine the weights of the first flow and the second flow, and obtain the weighted average flow as the fluid flow at the corresponding time. The system can improve the adaptability of downhole flow testing to the purity of fluid media and ensure the accuracy and reliability of downhole flow testing.

Description

Technical Field

[0001] The invention relates to the technical field of ultrasonic measurement of oilfield water injection wells, and in particular to a downhole flow rate testing system, method and device. Background Art

[0002] As oil fields are continuously developed, formation energy is continuously consumed. At present, most oil fields have entered the middle and late stages of water injection development. Oil field water injection and production technology can maintain oil layer pressure and reduce the decline rate of crude oil production. It is the most economical and effective technical means to achieve long-term high and stable production of oil fields. In the stratified water injection process, how to accurately measure the flow rate of injected fluids in each layer of the well is the key to achieving precise injection and oil recovery. Due to the uneven management level of major oil fields, there are large differences in the purity of the injected fluid medium. The ultrasonic measurement method based on the time difference method or the phase difference method has good test accuracy for the case where the fluid contains less solid particle impurities. However, when the content of solid particle impurities in the fluid exceeds a certain range, the accuracy of the single-channel ultrasonic flow measurement drops rapidly, and the test results cannot meet the application requirements of precise water injection in oil fields, which has an adverse effect on the effect of water injection and oil recovery. In addition, when there are certain solid particle impurities in the injected fluid, in order to prevent sand accumulation from blocking the water injection channel of the downhole dispenser, the ground control system needs to regularly regulate the downhole injection according to the sand cleaning control logic. However, current downhole ultrasonic flowmeters usually use monophonic ultrasound for flow testing, which has relatively strict requirements for the purity of the test fluid medium, has certain deficiencies in environmental adaptability, and cannot effectively monitor the solid particle impurity content of the fluid medium injected downhole. 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 specific implementation methods, provide a downhole flow testing system, method and device, which can improve the adaptability of downhole flow testing to the purity of fluid media and ensure the accuracy and reliability of downhole flow testing.

[0004] In a first aspect, an embodiment of the present invention provides a downhole flow rate testing system, including a downhole flow rate testing device and a ground control terminal;

[0005] The downhole flow rate testing device is used to collect and send to the control terminal an echo signal required to determine the first flow rate using the time difference method and an echo signal required to determine the second flow rate using the frequency difference method in each test cycle;

[0006] The control terminal is used to determine the first flow rate and the second flow rate. 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 rate threshold 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 a weighted average flow rate as the fluid flow rate at the corresponding time.

[0007] 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:

[0008] 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;

[0009] 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.

[0010] Optionally, the traffic threshold is 1 cubic meter per day.

[0011] Optionally, the downhole flow testing device comprises a test flow guide tube and first, second and third ultrasonic transducers arranged on the test flow guide tube, the first ultrasonic transducer and the second ultrasonic transducer are arranged axially symmetrically, and the first ultrasonic transducer and the third ultrasonic transducer are arranged centrally symmetrically;

[0012] The first ultrasonic transducer and the third ultrasonic transducer are used to alternately and cyclically transmit ultrasonic signals; when the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive a first echo signal, and the third ultrasonic transducer is used to receive a second echo signal; when the third ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive a third echo signal. The second echo signal and the third echo signal are used to determine a first flow rate using a time difference method, and the first echo signal is used to determine a second flow rate using a frequency difference method.

[0013] Optionally, the first flow difference threshold is 0.05 to 0.1 times the system range, and the second flow difference threshold is 0.15 to 0.2 times the system range.

[0014] Optionally, the first ultrasonic transducer and the third ultrasonic transducer have the same resonant frequency, and are both used to emit ultrasonic signals using their own resonant frequencies as excitation frequencies;

[0015] The first, second and third ultrasonic transducers are all used to collect echo signals at a sampling frequency greater than twice the resonance frequency.

[0016] Optionally, the first, second and third ultrasonic transducers are all used to collect echo signals with a sampling frequency of 15 to 25 times the resonant frequency.

[0017] Optionally, the first ultrasonic transducer and the third ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering it;

[0018] The second 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.

[0019] Optionally, the first, second and third ultrasonic transducers are arranged in the same plane.

[0020] In a second aspect, an embodiment of the present invention provides a downhole flow rate testing method, comprising:

[0021] The flow rate testing device of any of the above-mentioned downhole flow rate testing systems is lowered into the target position of the oil pipe of the target water injection well, and the flow rate sequence of the fluid at the target position is obtained based on the output data of its control terminal.

[0022] Optionally, obtaining the flow sequence of the fluid at the target position further includes:

[0023] The solid particle content level in the fluid corresponding to each time point included in the flow sequence is determined.

[0024] In a third aspect, an embodiment of the present invention provides a downhole flow rate testing method, comprising:

[0025] Acquire a first flow rate of a fluid at a target position of an oil pipe of a target water injection well determined according to a time difference method, and a second flow rate of the fluid at the target position determined according to a frequency difference method;

[0026] According to the relative size of the second flow rate and the set flow threshold and the difference 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.

[0027] In a fourth aspect, an embodiment of the present invention provides a downhole flow rate testing device, comprising a communication module and a flow rate determination module;

[0028] The communication module is used to obtain a first flow rate of the fluid at a target position of the oil pipe of the target water injection well determined according to the time difference method, and a second flow rate of the fluid at the target position determined according to the frequency difference method;

[0029] The flow determination module is used to determine the solid particle content level according to the relative size of the second flow and the set flow threshold and the difference between the first flow and the second flow, determine the weight of the first flow and the second flow, and obtain the weighted average flow as the fluid flow at the corresponding time.

[0030] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0031] (1) In the downhole flow rate testing system provided by the embodiment of the present invention, the ground control terminal uses the echo signal sent by the downhole flow rate testing device to determine the first flow rate by the time difference method and the second flow rate by the frequency difference method. 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 rate threshold and the difference amplitude 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. 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 rate testing.

[0032] (2) The downhole 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.

[0033] (3) In the downhole flow rate testing system provided by the embodiment of the present invention, the first ultrasonic transducer and the second ultrasonic transducer are axially symmetrically arranged to transmit ultrasonic signals alternately and cyclically, and the first ultrasonic transducer and the third ultrasonic transducer are centrally symmetrically arranged. The three axially symmetrically and centrally symmetrically arranged ultrasonic transducers realize multi-channel downhole flow rate testing, and the first flow rate is determined by the time difference method, and the second flow rate is determined by the frequency difference method. Then, the analysis results of the two flow rates are combined to determine the solid particle content level and obtain the weighted average flow rate.

[0034] 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.

[0035] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] 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:

[0037] Figure 1 It is a schematic diagram of the structure of a downhole flow rate testing device of a downhole flow rate testing system in an embodiment of the present invention. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] In order to solve the problem of low flow test accuracy caused by high solid particle impurity content in the fluid during stratified water injection flow test and the problem of monitoring the solid particle impurity content in the fluid medium injected downhole, an embodiment of the present invention provides a downhole flow test system, method and device.

[0043] Example

[0044] An embodiment of the present invention provides a downhole flow rate testing system, comprising a downhole flow rate testing device and a ground control terminal.

[0045] The downhole flow testing device is used to collect and send to the control terminal the echo signal required to determine the first flow using the time difference method and the echo signal required to determine the second flow using the frequency difference method in each test cycle.

[0046] See also Figure 1 As shown, it is a structural schematic diagram of the flow testing device, including a test flow guide tube 4 and a first ultrasonic transducer 1, a second ultrasonic transducer 2 and a third ultrasonic transducer 3 arranged on the test flow guide tube 4, the first ultrasonic transducer 1 and the second ultrasonic transducer 2 are axially symmetrically arranged, and the first ultrasonic transducer 1 and the third ultrasonic transducer 3 are centrally symmetrically arranged.

[0047] 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.

[0048] Figure 1 The arrow in the figure indicates the direction of fluid flow, and the position setting of the three ultrasonic transducers is only an example. Optionally, the first ultrasonic transducer may be located upstream, the third ultrasonic transducer may be located downstream, the second ultrasonic transducer may be axially symmetrical with the first ultrasonic transducer, or axially symmetrical with the third ultrasonic transducer, and so on, as long as the two ultrasonic transducers are axially symmetrical and centrally symmetrical.

[0049] The first ultrasonic transducer and the third ultrasonic transducer are used for emitting ultrasonic signals of a certain frequency in an alternating cycle.

[0050] When the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive the first echo signal and send it to the control terminal, and the third ultrasonic transducer is used to receive the second echo signal and send it to the control terminal; when the third ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive the third echo signal and send it to the control terminal, the second echo signal and the third echo signal are used to determine the first flow rate using the time difference method, and the first echo signal is used to determine the second flow rate using the frequency difference method.

[0051] by Figure 1 The positions of the three ultrasonic transducers shown in the figure are set as an example for explanation. The specific working principles of the three ultrasonic transducers are as follows:

[0052] 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 signals and convert them into voltage signals recognizable by the circuit, wherein the third ultrasonic transducer at the central symmetrical position obtains a countercurrent echo signal (second echo signal), and the second ultrasonic transducer at the axially symmetrical position obtains a reflected or scattered echo signal (first echo signal); the third ultrasonic transducer at the central symmetrical position is driven to emit an ultrasonic wave, and the first ultrasonic transducer on the other side receives the echo waveform signal to obtain a downstream echo signal (third echo signal).

[0053] In some embodiments, the first ultrasonic transducer and the third ultrasonic transducer have the same resonant frequency f, and are both used to emit ultrasonic signals with their own resonant frequency f as the excitation frequency. In order to ensure that the sampled signal has the original signal and the characteristics are not distorted, the first, second and third ultrasonic transducers are all used to collect echo signals with a sampling frequency greater than 2×f. At the same time, in order to improve the flow test accuracy, the sampling frequency is selected to be (15 to 25)×f.

[0054] The first ultrasonic transducer and the third ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering it through the hardware circuit; the second 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.

[0055] The control terminal is used to determine the first flow rate by using the time difference method based on the second echo signal and the third echo signal within the same period, and to determine the second flow rate by using the frequency difference method based on the first echo signal; for the same test period, the solid particle content level is determined 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, 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.

[0056] Specifically, the following steps may be included:

[0057] 1. Perform filtering and noise reduction preprocessing on the upstream and downstream echo signals (the second echo signal and the third 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.

[0058] 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.

[0059] 2. Perform filtering and noise reduction preprocessing on the obtained reflected and / or scattered echo signal (first 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.

[0060] The collected first 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 then 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.

[0061] 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.

[0062] The implementation of step 3 above, as shown in Table 1, includes the following situations:

[0063] Table 1 Statistics of solid particle content levels

[0064]

[0065] (1) When the second flow rate Q2 is not less than the set flow rate threshold S1

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] (2) When the second flow rate is less than the flow threshold S1

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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. In other words, the flow rate measured by the time difference method is also small, which is obviously inconsistent with reality, indicating the possibility of machine failure.

[0077] In some embodiments, the first flow difference threshold is determined to be 0.05 to 0.1 times of the system range, and the second flow difference threshold is determined to be 0.15 to 0.2 times of the system range; the flow threshold is determined to be 1 cubic meter / day.

[0078] In the downhole flow rate testing system provided by the embodiment of the present invention, the ground control terminal uses the echo signal sent by the downhole flow rate testing device to determine the first flow rate by the time difference method, and determines the second flow rate by the frequency difference method. 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 rate threshold and the difference amplitude 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. 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 rate testing.

[0079] The downhole flow testing system provided in the embodiment of the present invention can effectively monitor the solid particle content level of the downhole injected 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.

[0080] In the downhole flow testing system provided by the embodiment of the present invention, the first ultrasonic transducer and the second ultrasonic transducer are axially symmetrically arranged to transmit ultrasonic signals alternately and cyclically, and the first ultrasonic transducer and the third ultrasonic transducer are centrally symmetrically arranged; the three axially symmetrically and centrally symmetrically arranged ultrasonic transducers realize multi-channel downhole flow testing, and the first flow is determined by the time difference method, and the second flow is determined by the frequency difference method; then, the analysis results of the two flow rates are combined to determine the solid particle content level and obtain the weighted average flow.

[0081] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a downhole flow rate testing method, comprising:

[0082] The flow rate testing device of any of the above-mentioned downhole flow rate testing systems is lowered into the target position of the oil pipe of the target water injection well, and the flow rate sequence of the fluid at the target position is obtained based on the output data of its control terminal.

[0083] Optionally, obtaining the flow sequence of the fluid at the target position further includes:

[0084] The solid particle content level in the fluid corresponding to each time point included in the flow sequence is determined.

[0085] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a downhole flow rate testing method, comprising:

[0086] Acquire a first flow rate of a fluid at a target position of an oil pipe of a target water injection well determined according to a time difference method, and a second flow rate of the fluid at the target position determined according to a frequency difference method;

[0087] According to the relative size of the second flow rate and the set flow threshold and the difference 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.

[0088] The specific execution steps of the above method are described above and will not be repeated here.

[0089] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a downhole flow rate testing device, including a communication module and a flow rate determination module;

[0090] The communication module is used to obtain a first flow rate of the fluid at a target position of the oil pipe of the target water injection well determined according to the time difference method, and a second flow rate of the fluid at the target position determined according to the frequency difference method;

[0091] The flow determination module is used to determine the solid particle content level according to the relative size of the second flow and the set flow threshold and the difference between the first flow and the second flow, determine the weight of the first flow and the second flow, and obtain the weighted average flow as the fluid flow at the corresponding time.

[0092] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0093] 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.

[0094] 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.

[0095] 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 downhole flow testing system, characterized in that: Includes downhole flow testing equipment and ground control terminal; The downhole flow rate testing device is used to collect and send to the control terminal an echo signal required to determine the first flow rate using the time difference method and an echo signal required to determine the second flow rate using the frequency difference method in each test cycle; The control terminal is used to determine the first flow rate and the second flow rate. For the same test period, 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, the solid particle content level and the weights of the first flow rate and the second flow rate are determined through the following steps to obtain a weighted average flow rate as the fluid flow rate at the corresponding time: 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 rate threshold, if the absolute difference between the first flow rate and the second flow rate is not less than the first flow rate difference threshold, it is determined that the solid particle content is very small, and the first flow rate weight is determined to be 1 and the second flow rate weight is determined to be 0.

2. The system according to claim 1, characterized in that When the second flow rate is less than the flow rate threshold, if the absolute difference between the first flow rate and the second flow rate is less than the first flow rate difference threshold, the control terminal is further used to: Issues an alarm message indicating a possible equipment failure.

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

4. The system according to claim 1, characterized in that The downhole flow testing device comprises a test flow guide tube and first, second and third ultrasonic transducers arranged on the test flow guide tube, wherein the first ultrasonic transducer is axially symmetrically arranged with the second ultrasonic transducer, and the first ultrasonic transducer is centrally symmetrically arranged with the third ultrasonic transducer; The first ultrasonic transducer and the third ultrasonic transducer are used to alternately and cyclically transmit ultrasonic signals; when the first ultrasonic transducer transmits an ultrasonic signal, the second ultrasonic transducer is used to receive a first echo signal, and the third ultrasonic transducer is used to receive a second echo signal; when the third ultrasonic transducer transmits an ultrasonic signal, the first ultrasonic transducer is used to receive a third echo signal, the second echo signal and the third echo signal are used to determine a first flow rate using a time difference method, and the first echo signal is used to determine a second flow rate using a frequency difference method.

5. The system according to claim 4, characterized in that The first flow difference threshold is 0.05 to 0.1 times of the system range, and the second flow difference threshold is 0.15 to 0.2 times of the system range.

6. The system according to claim 5, characterized in that The first ultrasonic transducer and the third ultrasonic transducer have the same resonant frequency, and are both used to emit ultrasonic signals using their own resonant frequency as the excitation frequency; The first, second and third ultrasonic transducers are all used to collect echo signals at a sampling frequency greater than twice the resonance frequency.

7. The system according to claim 6, characterized in that The first, second and third ultrasonic transducers are all used to collect echo signals at a sampling frequency of 15 to 25 times the resonance frequency.

8. The system according to claim 4, characterized in that The first ultrasonic transducer and the third ultrasonic transducer are both used to directly collect the echo signal after amplifying and filtering; The second 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.

9. The system according to claim 4, characterized in that The first, second and third ultrasonic transducers are arranged in the same plane.

10. A downhole flow rate testing method, characterized in that: include: The flow rate testing device of the downhole flow rate testing system according to any one of claims 1 to 9 is lowered into the target position of the oil pipe of the target water injection well, and the flow rate sequence of the fluid at the target position is obtained based on the output data of its control terminal.

11. The method according to claim 10, characterized in that The step of obtaining the flow rate sequence of the fluid at the target position further includes: The solid particle content level in the fluid corresponding to each time point included in the flow sequence is determined.

12. A downhole flow rate testing method, characterized in that: include: Acquire a first flow rate of a fluid at a target position of an oil pipe of a target water injection well determined according to a time difference method, and a second flow rate of the fluid at the target position determined according to a frequency difference method; 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, the solid particle content level and the weights of the first flow rate and the second flow rate are determined through the following steps to obtain a weighted average flow rate as the fluid flow rate at the corresponding time: 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 rate threshold, if the absolute difference between the first flow rate and the second flow rate is not less than the first flow rate difference threshold, it is determined that the solid particle content is very small, and the first flow rate weight is determined to be 1 and the second flow rate weight is determined to be 0.

13. A downhole flow testing device, characterized in that: including a communication module and a flow determination module; The communication module is used to obtain a first flow rate of the fluid at a target position of the oil pipe of the target water injection well determined according to the time difference method, and a second flow rate of the fluid at the target position determined according to the frequency difference method; The flow determination module is used to determine the solid particle content level and the weights of the first flow and the second flow according to the relative size of the second flow and the set flow threshold and the difference between the first flow and the second flow through the following steps to obtain a weighted average flow as the fluid flow at the corresponding time: 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 rate threshold, if the absolute difference between the first flow rate and the second flow rate is not less than the first flow rate difference threshold, it is determined that the solid particle content is very small, and the first flow rate weight is determined to be 1 and the second flow rate weight is determined to be 0.

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