A detection device for electromagnetic flaw detection on the inner wall of oil casing

Abstract

The present invention discloses a detection device for electromagnetic flaw detection on the inner wall of an oil casing, belonging to the field of electromagnetic flaw detection technology. The device comprises: a base, a probe, multiple moving components, and multiple scraping strips. During oil and gas production, oil and gas can pass through the gap between the base and the inner wall of the oil casing without shutting down the wellhead, ensuring that flaw detection operations can be performed on the oil casing during normal use. The base is driven by the moving component to move along the inner wall of the oil casing. During the movement, multiple scraping strips cooperate with each other to scrape off adhesion layers such as scale, wax, and corrosion products adhering to the inner wall of the oil casing. The probe then performs flaw detection, thus realizing a working process of first scraping off the adhesion layer and then flaw detection. This can avoid blocking the probe's signal transmission and reception due to the adhesion layer.

Description

Technical Field

[0001] The present invention relates to the technical field of electromagnetic flaw detection, in particular to a detection device for electromagnetic flaw detection of the inner wall of an oil casing. Background Art

[0002] During oil and gas production, casing and tubing are key components connecting the surface to the reservoir. Their integrity and sealing directly impact the safety and continuity of production. To ensure the working condition of casing and tubing, regular nondestructive testing is required to identify potential cracks, corrosion, or other structural defects. Currently, electromagnetic flaw detection technology is widely used for defect detection of casing and tubing due to its non-contact and high sensitivity.

[0003] However, after long-term use, the oil casing will form layers of scale, wax and corrosion products, which will block the effective electromagnetic coupling between the probe and the metal body. Secondly, the high-speed flow of multiphase fluid (oil, gas, water, solid) in the pipe will distort the electromagnetic field distribution and drown out the defect signal. This leads to a significant limitation of the existing flaw detection equipment, that is, the flaw detection operation can only be carried out before the oil casing is put into use or after the production is stopped. Summary of the Invention

[0004] The purpose of the present invention is to provide a detection device for electromagnetic flaw detection of the inner wall of oil casing, so as to solve the problem that the detection device in the prior art can only perform flaw detection operation before the oil casing is put into use or after mining is stopped.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A detection device for electromagnetic flaw detection of the inner wall of an oil casing, comprising:

[0007] A base is provided with a gap between it and the inner wall of the oil casing for oil and gas circulation;

[0008] A probe, provided at one end of the base, for electromagnetic flaw detection;

[0009] A plurality of moving components are evenly distributed along the circumference of the base and drive the base to move;

[0010] A plurality of scraping strips are evenly arranged along the circumference of the base and in sliding contact with the inner wall of the oil casing.

[0011] A further technical solution is that the plurality of movable components are arranged in a circular array with the axis of the oil casing as the center;

[0012] A plurality of fixing grooves are provided on the periphery of the base;

[0013] Each movable component is disposed in a fixed slot and includes:

[0014] External parts;

[0015] The moving part is pushed by the outer abutment to contact the inner wall of the oil casing.

[0016] A further technical solution is that the moving part includes:

[0017] The movable bar has one end which is rotatably connected to the fixed groove with a direction perpendicular to the axis of the oil casing as the axis;

[0018] A first roller is provided at the other end of the moving bar;

[0019] The power part drives the first roller to rotate.

[0020] A further technical solution is that the outer abutment member has:

[0021] A retractable outer abutment shaft, the free end of which is hinged to the moving bar;

[0022] One end of the outer abutment member away from the outer abutment shaft is hinged in the fixing groove; when the outer abutment shaft is extended, it pushes the moving bar to rotate so that the first roller contacts the inner wall of the oil casing.

[0023] A further technical solution is that balancing pieces are evenly arranged radially around the circumference of the base, which include:

[0024] retractable balance shaft;

[0025] The second roller is provided at the free end of the balancing shaft and contacts the inner wall of the oil casing.

[0026] A further technical solution is that a guide block is provided at one end of the base away from the probe.

[0027] A further technical solution is that a gear ring is rotatably provided between the guide block and the base, and is coaxial with the oil casing;

[0028] A half gear is rotatably provided at one end of the base close to the guide block, and is located inside the gear ring and is meshed with the gear ring for transmission;

[0029] The plurality of scraper strips are evenly distributed along the circumference of the gear ring.

[0030] A further technical solution is that radially arranged protrusions are evenly arranged on the circumferential side of the gear ring, which include:

[0031] retractable extension shaft;

[0032] The scraper strip is connected to the free end of the extended shaft;

[0033] A detection groove is provided on one side of the scraper bar close to the probe, and pressure sensors are evenly distributed in the detection groove.

[0034] A further technical solution is that the guide block is a hemispherical structure facing away from the probe;

[0035] The top of the guide block is provided with a sliding groove coaxial with the oil casing;

[0036] A slide rod is provided in the slide groove through a spring; and a guide ball is provided at the outer end of the slide rod.

[0037] A further technical solution is that a scraper ring is slidably provided on the outer side wall of the probe;

[0038] A retaining ring groove is provided on one side of the base close to the scraper ring for sliding connection of the scraper ring;

[0039] A telescopic member arranged along the axis of the oil casing is provided in the retaining ring groove, and the free end of the telescopic shaft is connected to the scraper ring.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] During oil and gas production, oil and gas can pass through the gap between the base and the inner wall of the casing, eliminating the need to shut down the wellhead. This ensures that flaw detection can be performed during normal use of the casing. The base is driven by a moving assembly to move along the inner wall of the casing. During this movement, multiple scraping strips work together to scrape off layers of scale, wax, and corrosion products adhering to the inner wall of the casing. The probe then performs flaw detection, achieving a process of scraping off the adhesion layer before flaw detection. This prevents the adhesion layer from blocking the probe's signal transmission and reception. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention provides the following drawings for illustration:

[0043] Figure 1 It is a longitudinal sectional view of the detection device of the present invention in application state.

[0044] Figure 2 This is a top view of the detection device of the present invention in application state.

[0045] Figure 3 It is a three-dimensional diagram of the detection device of the present invention.

[0046] Figure 4 A three-dimensional diagram of the mobile assembly of the present invention.

[0047] Figure 5 It is a three-dimensional diagram of the local structure of the detection equipment of the present invention.

[0048] Figure 6 It is a three-dimensional diagram of the base of the present invention.

[0049] Figure 7It is a three-dimensional diagram of the structure on the scraper strip of the present invention.

[0050] Figure 8 It is a three-dimensional diagram of the scraper ring of the present invention.

[0051] Icons: 1-base, 2-casing and tubing, 3-gap, 4-probe, 5-moving assembly, 6-fixed groove, 7-moving bar, 8-rotating shaft, 9-first roller, 10-power part, 11-outer shaft, 12-balancing part, 13-second roller, 14-guide block, 15-gear ring, 16-limiting ring, 17-limiting groove, 18 rotating motor, 19-half gear, 20-protruding part, 21-detection groove, 22-pressure sensor, 23-slide rod, 24-scraper ring, 25-retaining ring groove, 26-telescopic part, 27-scraper bar. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0053] Example:

[0054] like Figures 1 to 8 As shown, the present invention provides an inspection device for electromagnetic flaw detection on the inner wall of an oil casing, comprising a cylindrical base 1; a gap 3 is provided between the base 1 and the inner wall of the oil casing 2, allowing oil and gas to pass through during oil and gas production to ensure normal production; a probe 4 for flaw detection on the oil casing 2 is provided at one end of the base 1; the probe 4 can perform flaw detection on the oil casing in conjunction with a multi-frequency eddy current detector; a plurality of moving assemblies 5 are evenly provided on the circumference of the base 1 (four are used as an example in this embodiment); the base 1 moves along the inner wall of the oil casing 2 via the moving assemblies 5; a plurality of scraping strips 27 are evenly provided on the circumference of the base 1 (four are used as an example in this embodiment); the plurality of scraping strips 27 are arranged in a circular array on the circumference of the base 1 with the axis of the oil casing 2 as the center; the scraping strips 27 are in sliding contact with the inner wall of the oil casing 2.

[0055] The principle and beneficial effects of the above technical solution:

[0056] During oil and gas production, oil and gas can pass through the gap 3 between the base 1 and the inner wall of the oil casing 2, eliminating the need to shut down the wellhead. This ensures that flaw detection can be performed on the oil casing 2 during normal use. The base 1 is driven by the moving assembly 5 to move along the inner wall of the oil casing 2. During this movement, multiple scraping strips 27 cooperate to scrape off layers of scale, wax, and corrosion products adhering to the inner wall of the oil casing 2. The probe 4 then performs flaw detection, achieving a process of scraping off the adhering layer first and then performing flaw detection. This prevents the adhering layer from blocking signal transmission and reception from the probe 4.

[0057] In this embodiment, multiple moving components 5 are arranged in a circular array on the circumference of the base 1 with the axis of the oil casing 2 as the center; a number of fixed grooves 6 are opened on the circumference of the base 1; each moving component 5 is arranged in a corresponding fixed groove 6; the moving components 5 include an outer resistance member and a moving member; the outer resistance member is located in the fixed groove 6 and is used to push the moving member to contact the inner wall of the oil casing 2.

[0058] The principle and beneficial effects of the above technical solution:

[0059] By pushing the moving member outwards through the outer abutment member, it is ensured that the moving member moves firmly in contact with the inner wall of the oil casing 2, thereby effectively avoiding poor contact or deviation in contact.

[0060] In this embodiment, the moving part includes a moving bar 7; one end of the moving bar 7 is rotatably arranged in a fixed groove 6 with a direction perpendicular to the axis of the oil casing 2 as the axis; a rotating shaft 8 is rotatably provided in the fixed groove 6; the rotating shaft 8 is arranged in a direction perpendicular to the axis of the oil casing 2; the moving bar 7 is rotatably sleeved on the rotating shaft 8 through a rotating hole; the other end of the moving bar 7 is provided with a first roller 9 and a power member 10 for driving the first roller 9 to rotate; the power member 10 is a servo motor.

[0061] The principle and beneficial effects of the above technical solution:

[0062] The first roller 9 is driven by a servo motor to realize active rotation, which not only enhances the fit and relative sliding control between the roller and the inner wall of the oil casing 2, but also can accurately adjust the rolling speed and pressure, thereby improving the sensitivity and stability of the equipment during operation.

[0063] In this embodiment, the external resistance member has a retractable external resistance shaft 11; the free end of the external resistance shaft 11 is hinged to the movable bar 7; the end of the external resistance member away from the external resistance shaft 11 is hinged in the fixed groove 6; the external resistance shaft 11 extends, thereby driving the movable bar 7 to rotate, so that the first roller 9 contacts the inner wall of the oil casing 2; the external resistance member is an electric cylinder.

[0064] The principle and beneficial effects of the above technical solution:

[0065] By controlling the extension or retraction of the outer shaft 11, the movable bar 7 can be driven to rotate about the rotating shaft 8, so that the first roller 9 at the end of the movable bar 7 can be expanded and retracted in the radial direction, ensuring that the first roller 9 always stably contacts the inner wall.

[0066] In this embodiment, the circumferential side of the base 1 is evenly provided with balancing members 12 arranged in a circular array along the radial direction; the balancing member 12 is an electric cylinder; the balancing member 12 has a retractable balancing shaft; the free end of the balancing shaft is provided with a second roller 13; the second roller 13 is in contact with the inner wall of the oil pipe sleeve.

[0067] The principle and beneficial effects of the above technical solution:

[0068] By controlling the extension or retraction of the balancing shaft of the balancing member 12, the second roller 13 can be brought into contact with the inner wall of the oil casing 2. The multiple balancing members 12 work together to provide support and position limiting, effectively suppressing radial oscillation or deviation of the flaw detection equipment during operation. They also dynamically adjust the contact pressure to accommodate local tolerance fluctuations on the inner wall of the oil casing 2, thereby improving the balance and stability of the equipment's operation. The synergistic effect of the multiple balancing members 12 further enhances the reliability of the equipment's long-term operation in harsh downhole environments and the consistency of the flaw detection signals.

[0069] In this embodiment, a guide block 14 is provided at one end of the base 1 away from the probe 4 .

[0070] The principle and beneficial effects of the above technical solution:

[0071] The guide block 14 can reduce resistance and guide the downhole liquid (such as crude oil, mud or well fluid) to flow in a set direction, reducing the fluid resistance and disturbance encountered by the equipment when operating in the wellbore, thereby improving the equipment's lowering efficiency and operating stability; in addition, the guide block 14 can also prevent impurities and mud from impacting the probe 4 area to a certain extent, effectively extending the service life of the probe 4 and ensuring the stability and accuracy of the flaw detection signal.

[0072] In this embodiment, a gear ring 15 coaxial with the oil casing 2 is rotatably provided between the guide block 14 and the base 1; coaxial limit rings 16 are provided on both sides of the gear ring 15; annular limit grooves 17 are provided on the corresponding side walls of the guide block 14 and the base 1; the limit ring 16 is rotatably provided in the corresponding limit groove 17; a rotating groove is provided at one end of the base 1 close to the guide block 14; a rotating motor 18 is provided in the rotating groove; a half gear 19 located on the inner side of the gear ring 15 is rotatably provided at the power end of the rotating motor 18; the half gear 19 is connected to the gear ring 15 through a gear; a plurality of scrapers 27 are evenly arranged on the circumference of the gear ring 15.

[0073] The principle and beneficial effects of the above technical solution:

[0074] By rotating the motor 18 to drive the half gear 19, the gear ring 15 can be driven to rotate intermittently, thereby driving multiple scraping strips 27 evenly distributed on the circumference of the gear ring 15 to rotate around the axis of the oil casing 2, thereby continuously scraping and cleaning the inner wall of the oil casing 2, thereby increasing the working area of ​​the scraping strips 27.

[0075] The gear connection between the half gear 19 and the ring gear 15 is an intermittent meshing structure. When the gears complete a rotation and re-enter the meshing zone, a brief secondary contact impact occurs. This vibration is transmitted through the ring gear 15 to the scraper strips 27 evenly arranged around its circumference, causing the scraper strips 27 to oscillate or bounce slightly, effectively overcoming the adhesion between the attached objects and the scraper strips 27. This allows foreign matter such as sand, grease, etc. to be shaken off the scraper strips 27, preventing a decrease in cleaning efficiency or clogging of the scraper strips 27.

[0076] In this embodiment, radially arranged extension members 20 are evenly arranged on the circumferential side of the gear ring 15; the extension members 20 are electric cylinders; the extension members 20 have a retractable extension shaft; a scraper 27 is connected to the corresponding extension shaft; a detection groove 21 is formed on the side of the scraper 27 close to the electromagnetic flaw detection member; and pressure sensors 22 that contact the inner wall of the oil casing 2 are evenly arranged in the detection grooves 21.

[0077] The principle and beneficial effects of the above technical solution:

[0078] After the scraper 27 scrapes off the attachments on the inner wall of the oil casing 2, the pressure sensor 22 can feedback the pressure of the inner wall of the oil casing 2. Since multiple scraper bars 27 are evenly distributed around the gear ring 15, the pressure sensors 22 on each scraper bar 27 form a distributed array, which can synchronously collect contact pressure data at different positions of the oil casing 2, thereby establishing an inner wall stress distribution map to assist in judging local abnormal areas. The possibility of cracking of the oil casing 2 can be judged by the numerical change of stress. When microcracks or deformation occur locally in the oil casing 2, the stiffness and contact characteristics of this area will be different from those of the surrounding areas. The pressure sensor 22 can reflect this as abnormal stress fluctuations. Through data fusion and analysis, the system can identify potential cracks or weakened areas and achieve early warning.

[0079] The contact information provided by the pressure sensor 22 can be used as an auxiliary basis for determining the working status of the electromagnetic flaw detection probe 4. When an abnormal flaw detection signal appears in a certain area and the pressure sensor 22 synchronously feedbacks stress changes, the accuracy of fault identification can be improved, avoiding false alarms or missed alarms caused by poor contact or errors.

[0080] In this embodiment, the guide block 14 is a hemispherical structure arranged away from the electromagnetic detection component; a slide groove coaxial with the axis of the oil casing 2 is opened at the top of the guide block 14; a slide rod 23 is provided in the slide groove through a spring sliding; and a guide ball is provided at the outer end of the slide rod 23.

[0081] The principle and beneficial effects of the above technical solution:

[0082] The guide ball, a sliding component, can be axially adjusted within the chute to accommodate varying flow rates and pressures, effectively dividing and redirecting the oil and gas flow. Combined with the wrapping and curved guiding properties of the hemispherical guide block 14, the oil and gas flow is effectively diverted and concentrated toward the area where the scraper strip 27 is located.

[0083] Through the flow field control of the guide ball, the oil and gas form a strong local flushing effect when flowing through the scraper 27 area, which helps to flush and remove impurities such as sludge and sand attached to the scraper 27, thereby improving the cleaning ability of the scraper 27 and maintaining its working efficiency.

[0084] The synergistic effect of the guide ball and the hemispherical structure not only reduces the interference of fluid disturbance on the detection path of the probe 4, but also avoids signal interference by guiding oil and gas to bypass the electromagnetic flaw detection parts, thereby improving the stability of the electromagnetic wave propagation path and enhancing the accuracy of the flaw detection results.

[0085] In this embodiment, a scraper ring 24 is slidably provided on the outer wall of the probe 4; a retaining ring groove 25 for sliding connection of the scraper ring 24 is opened on the side of the base 1 close to the scraper ring 24; a telescopic part 26 arranged along the axis of the oil casing 2 is provided in the retaining ring groove 25; the telescopic part 26 is an electric cylinder; the telescopic part 26 has a telescopic shaft; the scraper ring 24 is connected to the free end of the telescopic shaft.

[0086] The principle and beneficial effects of the above technical solution:

[0087] Driven by the electric cylinder, the scraper ring 24 actively cleans the outer wall of the probe 4, effectively removing oil stains, impurities or bubbles that may adhere to the surface of the probe 4 during the rising process of oil and gas, preventing stray objects from interfering with the electromagnetic signal transmission and reception paths, and improving the detection accuracy and data quality from the source.

[0088] Although the present invention has been described herein with reference to a number of illustrative embodiments thereof, it will be understood that numerous other modifications and implementations may be devised by those skilled in the art that fall within the scope and spirit of the principles disclosed herein. More specifically, within the scope of the present disclosure, the drawings, and the claims, numerous variations and modifications may be made to the components and / or layout of the subject combination arrangement. In addition to variations and modifications to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A detection device for electromagnetic flaw detection of the inner wall of oil casing, characterized in that: include: A base is provided with a gap between it and the inner wall of the oil casing for oil and gas circulation; A probe, provided at one end of the base, for electromagnetic flaw detection; A plurality of moving components are evenly distributed along the circumference of the base and drive the base to move; A plurality of scraping strips are evenly arranged along the circumference of the base and in sliding contact with the inner wall of the oil casing; A guide block is provided at one end of the base away from the probe; The guide block is a hemispherical structure facing away from the probe; The top of the guide block is provided with a sliding groove coaxial with the oil casing; A slide rod is provided in the slide groove through a spring; and a guide ball is provided at the outer end of the slide rod.

2. The detection device for electromagnetic flaw detection of the inner wall of oil casing according to claim 1, characterized in that: The plurality of movable components are arranged in a circular array with the axis of the oil casing as the center; A plurality of fixing grooves are provided on the periphery of the base; Each movable component is disposed in a fixed slot and includes: External parts; The moving part is pushed by the outer abutment to contact the inner wall of the oil casing.

3. The detection device for electromagnetic flaw detection of the inner wall of oil casing according to claim 2, characterized in that: The moving part includes: The movable bar has one end which is rotatably connected to the fixed groove with a direction perpendicular to the axis of the oil casing as the axis; A first roller is provided at the other end of the moving bar; The power part drives the first roller to rotate.

4. The detection device for electromagnetic flaw detection of the inner wall of oil casing according to claim 3, characterized in that: The outer abutment has: A retractable outer abutment shaft, the free end of which is hinged to the moving bar; One end of the outer abutment member away from the outer abutment shaft is hinged in the fixing groove; when the outer abutment shaft is extended, it pushes the moving bar to rotate, so that the first roller contacts the inner wall of the oil casing.

5. The detection equipment for electromagnetic flaw detection of the inner wall of oil casing according to claim 1, characterized in that: The balancing members are evenly arranged radially around the circumference of the base, and include: retractable balance shaft; The second roller is provided at the free end of the balancing shaft and contacts the inner wall of the oil casing.

6. The detection equipment for electromagnetic flaw detection of the inner wall of oil casing according to claim 1, characterized in that: A gear ring is rotatably provided between the guide block and the base, and is coaxial with the oil casing; A half gear is rotatably provided at one end of the base close to the guide block, and is located inside the gear ring and is meshed with the gear ring for transmission; The plurality of scraper strips are evenly distributed along the circumference of the gear ring.

7. The detection equipment for electromagnetic flaw detection of the inner wall of oil casing according to claim 6, characterized in that: The circumferential side of the gear ring is evenly provided with radially arranged protrusions, which include: retractable extension shaft; The scraper strip is connected to the free end of the extended shaft; A detection groove is provided on one side of the scraper bar close to the probe, and pressure sensors are evenly distributed in the detection groove.

8. The detection equipment for electromagnetic flaw detection of the inner wall of oil casing according to claim 1, characterized in that: A scraper ring is slidably provided on the outer side wall of the probe; A retaining ring groove is provided on one side of the base close to the scraper ring for sliding connection of the scraper ring; A telescopic member arranged along the axis of the oil casing is provided in the retaining ring groove, and the free end of the telescopic shaft is connected to the scraper ring.

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