Underground distributed phased array ultrasonic casing detection device and method

Abstract

The invention relates to the technical field of oil and gas field development, in particular to an underground distributed phased array ultrasonic casing detection device and method. The underground distributed phased array ultrasonic casing detection device comprises a detection system and a control system connected with the detection system, and the detection system comprises a cylindrical sealing structure and a distributed transducer arranged in the cylindrical sealing structure. The distributed transducer comprises at least three phased array ultrasonic probes which are rotationally arranged along the inner circumferential surface of the cylindrical sealing structure, and each phased array ultrasonic probe is correspondingly connected with a circuit nipple; wherein each phased array ultrasonic probe is used for transmitting and receiving an acoustic beam through a delay rule, so that imaging scanning and detection of the inner circumferential surface of the sleeve are realized; the circuit nipple is used for exciting the phased array ultrasonic probe and collecting and processing detection data of the phased array ultrasonic probe; and the control system is used for receiving the detection data of the corresponding phased array ultrasonic probe processed by each circuit short section and splicing and imaging according to the sleeve size structure.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas field development, and particularly relates to a downhole distributed phased array ultrasonic casing detection device and method. Background Art

[0002] Downhole casings, as an important part of oil and gas production, play a key role in supporting the wellbore, preventing collapse, isolating strata, and protecting the oil and gas flow channels. However, due to long-term service in extremely complex environments such as high temperature and pressure, corrosion, and mechanical stress, casings are extremely prone to problems such as wall thickness reduction, corrosion, deformation, and damage. These damages will lead to a decline in wellbore integrity, seriously reducing the stability of the oilfield. At the lightest, it will cause well leakage and affect the production efficiency. At the worst, it will trigger catastrophic consequences such as blowouts, reservoir pollution, and formation losses, resulting in significant environmental pollution and economic losses. Therefore, regularly conducting non-destructive testing on downhole casings is of great significance for ensuring the safety and normal production of oil wells.

[0003] Currently, relatively mature applications for detecting tubular goods such as oilfield casings include ultrasonic testing, electromagnetic testing, magnetic flux leakage testing, downhole video inspection, and radioactive isotope testing. Although to a certain extent, they can meet the requirements of casing defect detection, there are still different limitations in their applications. Ultrasonic testing has high sensitivity to internal defects of casings and can accurately measure changes in casing wall thickness. However, it can only send a single-direction sound beam and cannot achieve area-type detection, resulting in low detection efficiency. Electromagnetic testing can quickly detect defects such as corrosion, holes, and cracks in casings and has a good detection effect on the overall condition of casings. However, it can only detect the approximate location and range of casing defects, and is not precise enough in determining the specific shape and size of casing defects, lacking a quantification method. Downhole video inspection can directly display the location and degree of casing damage through clear images. However, it can only see within the computer's field of view, and the imaging quality is poor under conditions of insufficient light or turbid downhole media, and it cannot detect internal defects of casings. Radioactive isotope testing can detect tiny cracks in casings, with high detection accuracy and is suitable for harsh downhole environments. However, this detection method has certain radioactivity, the operation process is complex, there are certain risks to personnel and the environment, and the detection cost is high, and strict protection regulations need to be followed. Phased array ultrasonic testing technology is a new technology developed on the basis of conventional ultrasonic testing. By using an array of ultrasonic sensors and a delay focusing excitation method, it can achieve a detection surface within a certain range and at a certain angle. The focusing of the sound beam improves the detection sensitivity, making this technology have higher detection accuracy in casing detection. However, with the detection requirements of deep wells and ultra-deep wells, using phased array ultrasonic technology for 360° full-angle detection of casings has problems of low detection efficiency and slow detection speed.

[0004] The Chinese invention patent application with the publication number CN110672719A discloses a phased array ultrasonic detection device for in-pipe detection. By combining a phased array ultrasonic probe and front-end electronics and connecting them in sequence using coaxial cables, volumetric inspection of the pipe to be measured can be achieved, effectively improving the detection resolution and sensitivity. However, due to structural limitations, it is difficult for this phased array ultrasonic detection device to adapt to the complex downhole environment of high temperature and high pressure. The probe is extremely prone to damage and failure, making it unable to be used for downhole operations. At the same time, when applied to the 360° full-coverage detection of downhole casing, this phased array ultrasonic detection device has low efficiency and poor detection accuracy. Summary of the Invention

[0005] The purpose of the present invention is to provide a downhole distributed phased array ultrasonic casing detection device to solve the problem that the phased array ultrasonic detection device in the prior art is difficult to adapt to complex working conditions such as high temperature and high pressure during downhole casing detection, resulting in extremely easy damage and failure of the ultrasonic probe.

[0006] To solve the above problems, the present invention proposes a downhole distributed phased array ultrasonic casing detection device, and the technical solution adopted is as follows: A downhole distributed phased array ultrasonic casing detection device includes a detection system and a control system connected thereto. The detection system includes a cylindrical sealed structure and a distributed transducer disposed inside the cylindrical sealed structure. The distributed transducer includes at least three phased array ultrasonic probes rotatably arranged along the inner circumferential surface of the cylindrical sealed structure, and each phased array ultrasonic probe is correspondingly connected to a circuit stub. Among them, each phased array ultrasonic probe completes the emission and reception of sound beams through the time delay rule, realizing the imaging scan and detection of the inner circumferential surface of the casing. The circuit stub is used to excite the phased array ultrasonic probe and collect and process the detection data of the phased array ultrasonic probe. The control system is used to receive the detection data of the corresponding phased array ultrasonic probe processed by each circuit stub and splice and image according to the size structure of the casing.

[0007] Further, the phased array ultrasonic probe includes 16 elements or 32 elements, and the 16 elements or 32 elements are convex arrays evenly arranged in an arc shape.

[0008] Further, the center frequency range of the phased array ultrasonic probe is 200 kHz to 5 MHz, the length of the element is 10 mm, the spacing range between adjacent elements is 0.5 to 0.6 mm, and the width range of the element is 0.3 to 0.4 mm. Further, the phased array ultrasonic probes are rotatably arranged at equal distances and evenly along the inner circumferential surface of the cylindrical sealed structure.

[0009] Further, the number of the phased array ultrasonic probes is 3 to 4.

[0010] Further, the cylindrical sealing structure includes a housing made of a temperature- and pressure-resistant composite material, and a corrosion-resistant coating is provided on the outer circumferential surface of the housing.

[0011] Further, the circuit sub-section includes a phased array ultrasonic emission module, a receiving module, and a data acquisition module; the phased array ultrasonic emission module is connected to the receiving module and is used to excite a phased array ultrasonic probe to generate a sound beam. The sound beam interacts with the defects on the inner wall of the casing to generate an ultrasonic echo signal, and transmits the ultrasonic echo signal to the receiving module; the receiving module is connected to the data acquisition module and is used to receive the ultrasonic echo signal, convert the ultrasonic echo signal into an electrical signal, and then transmit it to the data acquisition module; the data acquisition module is used to receive the electrical signal and perform sampling and real-time data processing on the electrical signal using a parallel algorithm.

[0012] Further, the detection system and the control system are connected by an optical and electrical composite cable.

[0013] The present invention also provides a downhole distributed phased array ultrasonic casing detection method, based on the above-mentioned downhole distributed phased array ultrasonic casing detection device, including the following steps: Step S1, coaxially place the cylindrical sealing structure inside the casing; Step S2, the circuit sub-section excites the phased array ultrasonic probe, and each phased array ultrasonic probe completes the emission and reception of the sound beam through the time delay rule, realizing the imaging scan and detection of the inner circumferential surface of the casing; Step S3, each circuit sub-section collects and processes the detection data of the corresponding phased array ultrasonic probe and transmits it to the control system; Step S4, the control system receives the detection data of the corresponding phased array ultrasonic probe processed by each circuit sub-section and splices and images according to the size structure of the casing to complete the detection.

[0014] Further, the specific process of each phased array ultrasonic probe completing the emission and reception of the sound beam through the time delay rule, realizing the imaging scan and detection of the inner circumferential surface of the casing includes: Taking the axis of the array element of each phased array ultrasonic probe as the 0° demarcation line, controlling the sound beam line to scan a set angular range to the left and right of the demarcation line, so that all phased array ultrasonic probes cover the 360° range of the inner circumferential surface of the casing, and completing the scan of one week of the inner circumferential surface of the casing.

[0015] Compared with the prior art, the present application has the following beneficial effects: The present invention is an improved invention. The present invention provides a downhole distributed phased array ultrasonic casing detection device, which uses multiple phased array ultrasonic probes and integrates them into a cylindrical sealed structure to form a distributed transducer. Its outer shape is a closed cylinder, achieving a high detection speed and meeting the requirements of fast and large-scale detection in the downhole; at the same time, each phased array ultrasonic probe completes the emission and reception of sound beams through the delay rule, completes the imaging scan of the inner circumferential surface of the casing, realizes the large-scale detection of the sound field coverage, significantly improves the detection range and efficiency, and has high efficiency and accuracy during the 360° full casing detection, can detect internal defects of the casing early, extend the service life of the casing, and avoid downhole accidents. Moreover, the detection device can adapt to the complex downhole environment of high temperature and high pressure, prevent it from being interfered by the downhole complex environment and electromagnetic fields, ensure the detection accuracy, improve the detection speed, and improve the safety of oilfield operations.

[0016] The downhole distributed phased array ultrasonic casing detection device of the present invention adopts the design of a distributed transducer. By reasonably configuring multiple phased array ultrasonic probes, it realizes the full circumferential coverage of the sound beam on the inner circumferential surface of the casing; at the same time, each phased array ultrasonic probe is correspondingly connected with a circuit short section, and the circuit short section is used to excite the phased array ultrasonic probe and collect and process the detection data of the phased array ultrasonic probe, enabling each phased array ultrasonic probe to perform independent data transmission, significantly improving the detection efficiency and accuracy; at the same time, the downhole distributed phased array ultrasonic casing detection device of the present invention adopts a precision-machined cylindrical sealed structure, which can operate stably in the complex downhole environment and perform casing damage detection, improving the reliability of the detection device.

[0017] The center frequency range of the phased array ultrasonic probe is 200 kHz to 5 MHz, the length of the array element is 10 mm, the spacing range between adjacent array elements is 0.5 to 0.6 mm, and the width range of the array element is 0.3 to 0.4 mm. At the same time, the sensitivity and lateral resolution of the array elements of the phased array ultrasonic probe are ensured to improve the detection ability of the phased array ultrasonic probe.

[0018] The phased array ultrasonic probes are arranged at equal distances and evenly rotated along the inner circumferential surface of the cylindrical sealed structure, which is convenient to simply and effectively realize the scanning detection of one week of the inner circumferential surface of the casing.

[0019] The number of the phased array ultrasonic probes is 3 to 4. The structure is simple and the volume is small. It can be placed inside the narrow downhole casing and can ensure the realization of the scanning detection of one week of the inner circumferential surface of the casing.

[0020] The cylindrical sealed structure includes a housing. The material of the housing is a composite material with temperature and pressure resistance. An anti-corrosion coating is provided on the outer circumferential surface of the housing to prevent it from being interfered by the downhole complex environment and electromagnetic fields and improve the detection accuracy.

[0021] The detection system and the control system are connected by an optical and electrical composite cable, enabling the device to operate stably in a complex downhole environment for casing damage detection and improving the system reliability. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram of the downhole distributed phased array ultrasonic casing detection device of the present application; Figure 2 is a schematic structural diagram of the detection system in the downhole distributed phased array ultrasonic casing detection device of the present application; Figure 3 is a schematic structural diagram of the distributed transducer in the downhole distributed phased array ultrasonic casing detection device of the present application; Figure 4 is a schematic structural diagram of the distribution of a phased array ultrasonic probe element in the downhole distributed phased array ultrasonic casing detection device of the present application.

[0023] In the figure, 1 is the wellbore wall, 2 is the annulus, 3 is the casing, 4 is the detection system, 5 is the optical and electrical composite cable, 6 is the computer, 7 is the circuit nipple, 8 is the distributed transducer, 9 is the phased array ultrasonic probe, and 10 is the element. Detailed Embodiment

[0024] As cited in the background art, phased array ultrasonic testing devices in the prior art are difficult to adapt to complex working conditions such as high temperature and high pressure during downhole casing testing, resulting in easy damage and failure of ultrasonic probes. Therefore, the present invention provides a downhole distributed phased array ultrasonic casing testing device, including: a detection system 4 and a control system connected thereto. The detection system 4 is used to detect the inner circumferential surface of the casing 3, and the control system is used to control the detection system 4 to perform detection and integrate the detection data. The detection system 4 includes a cylindrical sealing structure and a distributed transducer 8 disposed inside the cylindrical sealing structure. The distributed transducer 8 includes at least three phased array ultrasonic probes 9 rotatably arranged along the inner circumferential surface of the cylindrical sealing structure, and each phased array ultrasonic probe 9 is correspondingly connected to a circuit stub 7. Among them, each phased array ultrasonic probe 9 completes the emission and reception of sound beams through a delay rule, realizing the change of the focusing depth and the sound beam azimuth, so that all phased array ultrasonic probes 9 complete the imaging scan and detection of the inner circumferential surface of the casing 3. The circuit stub 7 is used to excite the phased array ultrasonic probe 9 and collect and process the detection data of the phased array ultrasonic probe 9. The control system is used to receive the detection data of the corresponding phased array ultrasonic probe 9 processed by each circuit stub 7 and splice and image according to the size structure of the casing 3. The downhole distributed phased array ultrasonic casing testing device of the present invention adopts the design of the distributed transducer 8. By reasonably configuring multiple phased array ultrasonic probes 9, it realizes full coverage of the circumferential detection of the inner peripheral surface of the casing 3 through acoustic focusing and sound beam deflection. At the same time, each phased array ultrasonic probe 9 is correspondingly connected to a circuit stub 7, and the circuit stub 7 is used to excite the phased array ultrasonic probe 9 and collect and process the detection data of the phased array ultrasonic probe 9, enabling each phased array ultrasonic probe 9 to perform independent data transmission, significantly improving the detection efficiency and accuracy. At the same time, the downhole distributed phased array ultrasonic casing testing device of the present invention adopts a precisely machined cylindrical sealing structure, which can operate stably in a complex downhole environment and perform casing damage detection, improving the reliability of the testing device.

[0025] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances, so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0026] Specific Embodiment 1 of the downhole distributed phased array ultrasonic casing testing device of the present invention: In this embodiment, as shown in Figure 1 , 2 , 3, and 4, the downhole distributed phased array ultrasonic casing detection device includes a detection system 4 and a control system connected thereto. The detection system 4 and the control system are connected through an optical and electrical composite cable 5. The detection system 4 includes a cylindrical sealing structure and a distributed transducer 8 disposed inside the cylindrical sealing structure. The distributed transducer 8 includes 4 phased array ultrasonic probes 9 rotatably arranged along the inner circumferential surface of the cylindrical sealing structure. Each phased array ultrasonic probe 9 corresponds to independent signal transmission data, and each phased array ultrasonic probe 9 is correspondingly connected to a circuit stub 7. At this time, the circuit stub 7 is connected to the phased array ultrasonic probe 9 through the optical and electrical composite cable 5 and is connected to the control system through the optical and electrical composite cable 5. Among them, the optical and electrical composite cable 5 is provided with a buffer layer and a protective layer, which can ensure the stability of data transmission.

[0027] Among them, each phased array ultrasonic probe 9 completes the emission and reception of the sound beam through the time delay rule, and realizes the imaging scan and detection of the inner circumferential surface of the casing 3. Specifically, the control system controls the phased array ultrasonic probe 9 to change the deflection azimuth of the sound beam of the phased array ultrasonic probe 9 through the time delay rule setting, controls the sound beam to be incident on the inner wall of the casing 3 at different angles respectively, and completes the 360° circumferential coverage scan; at the same time, the focusing depth is changed to detect the deep defects inside the casing 3. The circuit stub 7 is used to excite the phased array ultrasonic probe 9 and collect and process the detection data of the phased array ultrasonic probe 9; the control system is used to receive the detection data of the corresponding phased array ultrasonic probe 9 processed by each circuit stub 7 and splice and image according to the size structure of the casing 3. Here, the control system is a computer 6. During use, there is an annulus 2 between the casing 3 and the wellbore 1. The cylindrical sealing structure is placed inside the downhole casing 3, so that the center of the cylindrical sealing structure coincides with the axial center line of the casing 3, ensuring that the sound beam lines of the elements 10 of each phased array ultrasonic probe 9 of the distributed transducer 8 are vertically incident into the casing 3, and the cylindrical sealing structure can further prevent the annulus 2 from damaging the phased array ultrasonic probe 9; at the same time, the diameter size of the detection system 4 cannot exceed the inner diameter of the casing 3. Because it is necessary to detect downhole casings 3 with various inner diameter sizes, in this embodiment, the diameter of the detection system 4 is finally selected to be 80 mm.

[0028] When detecting the downhole casing 3, the more the number of elements 10 of the phased array ultrasonic probe 9, the stronger the focusing ability of the sound beam and the higher the lateral resolution. However, the size of the phased array ultrasonic probe 9 will also increase accordingly. Limited by the narrow downhole space, in this embodiment, the number of elements 10 of the phased array ultrasonic probe 9 is finally selected as 16 elements 10 or 32 elements 10, and the 16 elements 10 or 32 elements 10 are convex arrays arranged uniformly in an arc. Since the debris in the annulus 2 will affect the sound wave, it is not appropriate to choose a high-frequency probe. Therefore, the central frequency range of the phased array ultrasonic probe 9 is 200 kHz to 5 MHz, the length of the element 10 is 10 mm, the spacing range between adjacent elements 10 is 0.5 to 0.6 mm, and the width range of the element 10 is 0.3 to 0.4 mm. Here, each phased array ultrasonic probe 9 completes the emission and reception of the sound beam through the time delay law, specifically referring to: each phased array ultrasonic probe 9 controls the time delay of the excitation and reception pulses of each element 10 to change the phase relationship of the sound wave emitted (or received) by the element 10 to reach (or come from) a certain point in the casing 3. Among them, the material of the element 10 of the phased array ultrasonic probe 9 is selected as a modified piezoelectric composite material, which can optimize the acoustic impedance through proportioning, reduce the sound energy reflection, and is suitable for the high-precision detection and multi-angle scanning required in the detection of the downhole casing 3.

[0029] During detection, in order to cover a sufficiently large range of the inner wall of the casing 3, a relatively large fan scan angle is usually required. However, an excessive angle will lead to a decrease in detection resolution. Therefore, in this embodiment, with the axis of the element 10 of the phased array ultrasonic probe 9 as the 0° demarcation line, the sound beam line is controlled to scan 50° to the left and right of the demarcation line. Each phased array ultrasonic probe 9 can scan and cover a range of 100°, and 4 phased array ultrasonic probes 9 can cover a 360° range to complete the scanning of the entire circumferential surface of the casing 3.

[0030] In other embodiments, the distributed transducer 8 includes 3 phased array ultrasonic probes 9 arranged along the inner circumferential surface of the cylindrical sealing structure. During detection, with the axis of the element 10 of the phased array ultrasonic probe 9 as the 0° demarcation line, the sound beam line is controlled to scan 65° to the left and right of the demarcation line. Each phased array ultrasonic probe 9 can scan and cover 130°, and 3 phased array ultrasonic probes 9 can cover a 360° range to complete the scanning of the casing 3 for one week.

[0031] Specific embodiment 2 of the downhole distributed phased array ultrasonic casing detection device of the present invention: Based on the above technical concept of the present invention, or on the basis of the specific embodiments of the present invention introduced above, another embodiment is provided below.

[0032] The phased array ultrasonic probes 9 can be evenly arranged in rotation at unequal distances along the inner circumference of the cylindrical sealing structure. However, when the spacing between some adjacent phased array ultrasonic probes 9 is too large, a single phased array ultrasonic probe 9 may not be able to scan a position. When the spacing between some adjacent phased array ultrasonic probes 9 is too small, a large number of repeated scanning positions may exist. Therefore, in this embodiment, preferably, as Figure 3 As shown, the phased array ultrasonic probes 9 are evenly and evenly arranged in rotation along the inner circumference of the cylindrical sealing structure, so as to simply and effectively scan and detect the inner circumference of the casing 3.

[0033] In this embodiment, the cylindrical sealing structure includes a shell, the shell is made of heat-resistant and pressure-resistant material, and a corrosion-resistant coating is provided on the outer circumference of the shell. Due to the complex downhole environment, in order to protect the phased array ultrasonic probe 9, the shell is made of pressure-resistant and temperature-resistant material and is precisely processed to achieve sealed installation.

[0034] Specific embodiment 3 of the downhole distributed phased array ultrasonic casing detection device of the present invention: Based on the above technical concept of the present invention, or based on the above specific embodiment of the present invention, another embodiment is provided below.

[0035] In this embodiment, the circuit short section 7 includes a phased array ultrasonic transmitting module, a receiving module and a data acquisition module. The phased array ultrasonic transmitting module is connected to the receiving module, and is used to excite the phased array ultrasonic probe 9 to generate a sound beam. The sound beam interacts with the inner wall of the sleeve 3 to generate an ultrasonic echo signal, and the ultrasonic echo signal is transmitted to the receiving module; the receiving module is connected to the data acquisition module, and is used to receive the ultrasonic echo signal, and convert the ultrasonic echo signal into an electrical signal and transmit it to the data acquisition module; the data acquisition module is used to receive the electrical signal, and use a parallel algorithm to sample the electrical signal and perform real-time data processing; finally, the processed electrical signal is transmitted to the computer 6 through the optoelectronic composite cable 5 to complete signal analysis splicing and data processing.

[0036] Specific embodiment 1 of the downhole distributed phased array ultrasonic casing detection method of the present invention: The present application also provides a downhole distributed phased array ultrasonic casing detection method, based on the above-mentioned downhole distributed phased array ultrasonic casing detection device, comprising the following steps: First, a cylindrical sealing structure is coaxially placed inside the casing 3; Secondly, the circuit short section 7 excites the phased array ultrasonic probe 9, and each phased array ultrasonic probe 9 completes the emission and reception of the sound beam through the delay law, thereby realizing the imaging scanning and detection of the inner circumference of the casing 3; Then, the circuit short section 7 collects and processes the detection data of the phased array ultrasonic probe 9 and transmits it to the control system; Finally, the control system receives the detection data of each phased array ultrasonic probe 9 processed by the circuit sub-section 7 and splices and images according to the size and structure of the casing 3 to complete the detection.

[0037] Among them, each phased array ultrasonic probe 9 completes the emission and reception of sound beams through the time-delay rule, and the imaging scan and detection of the inner circumferential surface of the casing 3 specifically include: Taking the axis of the central element 10 of each phased array ultrasonic probe 9 as the 0° dividing line, the sound beam line is controlled to scan a set angular range to the left and right of the dividing line, so that all phased array ultrasonic probes 9 cover the 360° range of the inner circumferential surface of the casing 3, and the scan of one week of the inner circumferential surface of the casing 3 is completed.

[0038] Specifically, a downhole distributed phased array ultrasonic casing detection method includes the following steps: First, a cylindrical sealing structure is placed inside the casing 3 so that the center of the cylindrical sealing structure coincides with the central axis of the casing 3; Secondly, the computer 6 controls the circuit sub-section 7 to excite the phased array ultrasonic probe 9 through the phased array ultrasonic emission module, and each phased array ultrasonic probe 9 uses the time-delay rule to complete the emission and reception of sound beams, and realizes the imaging scan and detection of the inner circumferential surface of the casing 3; Then, the circuit sub-section 7 collects and processes the detection data of the phased array ultrasonic probe 9 through the receiving module and the data acquisition module, and transmits it to the computer 6; Finally, the computer 6 receives the detection data of each phased array ultrasonic probe 9 processed by the circuit sub-section 7 and splices and images according to the size and structure of the casing 3 to complete the detection of the casing 3.

[0039] As described above, it is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention is subject to the claims. Any equivalent structural changes made by using the description and drawings of the present invention should be included in the protection scope of the present invention by the same token.

Claims

1. An underground distributed phased array ultrasonic casing detection device, characterized in that Comprising: A detection system (4) and a control system connected thereto, the detection system (4) comprising a cylindrical sealing structure and a distributed transducer (8) disposed inside the cylindrical sealing structure, the distributed transducer (8) comprising at least three phased array ultrasonic probes (9) rotatably arranged along the inner circumferential surface of the cylindrical sealing structure, and each phased array ultrasonic probe (9) being correspondingly connected to a circuit stub (7); wherein, each phased array ultrasonic probe (9) completes the transmission and reception of sound beams through a delay rule to realize the imaging scan and detection of the inner circumferential surface of the casing (3); the circuit stub (7) is used to excite the phased array ultrasonic probe (9) and collect and process the detection data of the phased array ultrasonic probe (9); the control system is used to receive the detection data of the corresponding phased array ultrasonic probe (9) processed by each circuit stub (7) and splice and image according to the size structure of the casing (3).

2. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, wherein The phased array ultrasonic probe (9) comprises 16 array elements (10) or 32 array elements (10), and the 16 array elements (10) or 32 array elements (10) are convex arrays arranged uniformly in an arc shape.

3. The downhole distributed phased array ultrasonic casing inspection device according to claim 2, wherein, The center frequency range of the phased array ultrasonic probe (9) is 200 kHz to 5 MHz, the length of the array element (10) is 10 mm, the spacing range between adjacent array elements (10) is 0.5 to 0.6 mm, and the width range of the array element (10) is 0.3 to 0.4 mm.

4. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, characterized in that The phased array ultrasonic probes (9) are rotatably arranged equidistantly and uniformly along the inner circumferential surface of the cylindrical sealing structure.

5. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, characterized in that, The number of the phased array ultrasonic probes (9) is 3 to 4.

6. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, characterized in that, The cylindrical sealing structure comprises a housing, the material of the housing is a temperature and pressure resistant material, and a corrosion resistant coating is provided on the outer circumferential surface of the housing.

7. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, characterized in that The circuit stub (7) comprises a phased array ultrasonic transmitting module, a receiving module and a data acquisition module; the phased array ultrasonic transmitting module is connected to the receiving module and is used to excite the phased array ultrasonic probe (9) to generate a sound beam, the sound beam acts on the inner wall of the casing (3) to generate an ultrasonic echo signal, and transmits the ultrasonic echo signal to the receiving module; the receiving module is connected to the data acquisition module and is used to receive the ultrasonic echo signal, convert the ultrasonic echo signal into an electrical signal and then transmit it to the data acquisition module; the data acquisition module is used to receive the electrical signal and sample and perform real-time data processing on the electrical signal by using a parallel algorithm.

8. The downhole distributed phased array ultrasonic casing inspection device according to claim 1, characterized in that The detection system (4) and the control system are connected through an optical and electrical composite cable (5).

9. A downhole distributed phased array ultrasonic casing inspection method, characterized in that, Based on the downhole distributed phased array ultrasonic casing detection device according to any one of claims 1-8, comprising the following steps: Step S1, coaxially placing the cylindrical sealing structure inside the casing (3); Step S2, the circuit stub (7) excites the phased array ultrasonic probe (9), and each phased array ultrasonic probe (9) completes the transmission and reception of sound beams through a delay rule to realize the imaging scan and detection of the inner circumferential surface of the casing (3); Step S3, each circuit stub (7) collects and processes the detection data of the corresponding phased array ultrasonic probe (9) and transmits it to the control system; Step S4, the control system receives the detection data of the corresponding phased array ultrasonic probe (9) processed by each circuit stub (7) and performs stitching imaging according to the size and structure of the casing (3) to complete the detection.

10. The downhole distributed phased array ultrasonic casing inspection method according to claim 9, characterized in that, Each of the phased array ultrasonic probes (9) completes the emission and reception of sound beams through the time delay rule, and the imaging scan and detection of the inner circumferential surface of the casing (3) are specifically as follows: Taking the axis of the array element (10) of each phased array ultrasonic probe (9) as the 0° demarcation line, the sound beam line is controlled to scan a set angular range to the left and right of the demarcation line, so that all the phased array ultrasonic probes (9) cover the 360° range of the inner circumferential surface of the casing (3), and the scanning of one week of the inner circumferential surface of the casing (3) is completed.

Images