A downhole acoustic imaging logging mechanism for safety detection

Abstract

This invention relates to the field of downhole safety detection equipment technology, and discloses an acoustic imaging logging mechanism for downhole safety detection, including a logging device, a processing shaft, and a detection shaft. An annular sleeve is provided on the detection shaft, and a movable shaft is installed inside the annular sleeve. A detection frame is provided at the end of the movable shaft, and a monitoring rod is provided inside the detection frame. A roller is provided at the end of the monitoring rod, and a disassembly frame is provided on one side of the monitoring rod. An annular disc is provided inside the disassembly frame, and a sliding block is installed on the annular disc. An arc-shaped panel is installed at the end of the sliding block, and a button is installed on the inner wall of the disassembly frame. This acoustic imaging logging mechanism for downhole safety detection senses the presence of mud cake by the change in the rotational speed of the roller as it rolls on the well wall surface. When the roller passes over the mud cake, the rotational speed decreases, the centrifugal force on the sliding block decreases, causing the arc-shaped panel to separate from the button, triggering the scraper to extend and scrape off the mud cake, thus avoiding the absorption and scattering of acoustic signals by the mud cake.

Description

Technical Field

[0001] This invention relates to the field of downhole safety detection equipment technology, specifically to an acoustic imaging logging mechanism for downhole safety detection. Background Technology

[0002] Acoustic imaging logging is an important method for obtaining wellbore geological information in downhole safety inspection. By transmitting high-frequency acoustic pulses into the wellbore and receiving the echo signals, an acoustic image of the wellbore can be generated. This image can then be used to identify geological structures such as fractures, pores, and bedding, and to evaluate the wellbore geometry and wellbore stability. In downhole safety inspection operations, the quality of acoustic imaging logging data is directly related to the accurate assessment of potential wellbore safety hazards.

[0003] During drilling, to prevent blowouts, the static pressure of the drilling fluid column is usually slightly higher than the formation pressure. This pressure drives the drilling fluid to permeate into the reservoir. As the drilling fluid continuously permeates into the reservoir, solid particles gradually settle on the wellbore, forming a mud cake. The mud cake has very poor permeability and, once formed, prevents further penetration of the drilling fluid into the formation. However, the presence of the mud cake poses a significant interference to acoustic detection. On one hand, the mud cake reduces the ultrasonic energy reflected from the wellbore. When the mud cake layer is thick, estimating formation parameters using acoustic amplitude attenuation will result in… Incorrect results; on the other hand, the formation of mud cakes due to mud filtration in the permeable section will cause wellbore reduction, affecting sonic transit time logging. Furthermore, when the mud cake layer is thick, it will also generate so-called "mud cake sliding waves" and "mud cake refracted sliding waves." These additional sonic signals will be superimposed on the real formation echo, further interfering with the accuracy of sonic imaging. Since sonic imaging logging relies on the accurate measurement of echo amplitude and propagation time, the presence of mud cakes directly affects the ability of sonic detection data to reflect real formation information. Therefore, we propose a sonic imaging logging mechanism for downhole safety detection. Summary of the Invention

[0004] The purpose of this invention is to provide an acoustic imaging logging mechanism for downhole safety inspection, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a downhole safety detection acoustic imaging logging mechanism, comprising a logging device, a processing shaft installed at the bottom of the logging device, and a detection shaft fixedly installed at the bottom of the processing shaft. Multiple annular sleeves are fixedly installed on the outer wall of the detection shaft. A movable shaft is slidably installed inside each annular sleeve, and one end of the movable shaft penetrates through the inner wall of the annular sleeve and extends to the outside. A detection frame is also provided at the end of the movable shaft located outside the annular sleeve. A limiting shaft is fixedly installed at one end of the movable shaft. The detection frame is rotatably connected to the limiting shaft. A monitoring rod frame is provided inside the detection frame.

[0006] One end of the monitoring rod extends through the inner wall of the detection frame and outwards. A roller is also installed at the outer end of the monitoring rod, on which a main shaft rotatably connects to the inner wall of the detection frame is fixedly mounted. A disassembly frame is fixedly mounted on one side of the monitoring rod, and an annular disc frame is installed inside the disassembly frame. Multiple guide grooves are also provided on the annular disc frame, and a sliding block is slidably installed inside each guide groove. A spring connects the sliding block to the inner wall of the guide groove. One end of the sliding block is located outside the guide groove and has an arc-shaped panel fixedly mounted on it. A button is fixedly mounted on the inner wall of the disassembly frame, located on the movement trajectory of the arc-shaped panel. The annular disc frame and the main shaft are connected via a drive unit. A processing sleeve is fixedly mounted on the processing shaft, and multiple scraper sections are provided on the outer wall of the processing sleeve. A processing unit for driving the scrapers to remove mud cake from the well wall is located inside the processing sleeve.

[0007] Preferably, the drive unit includes a drive gear disposed inside the disassembly frame, the drive gear being fixedly mounted on the main shaft, and a driven gear disposed inside the disassembly frame, the driven gear meshing with the drive gear, a transmission shaft being fixedly mounted on the driven gear, the transmission shaft being rotatably connected to the inner wall of the disassembly frame, and an annular disc being fixedly mounted at the end of the transmission shaft.

[0008] Preferably, a spring mechanism is connected between the monitoring rod and the inner wall of the detection frame, and a touch rod is fixedly installed on the top of the monitoring rod. A second button is embedded in the inner wall of the top of the detection frame. The second button is located on the movement trajectory of the touch rod, and a response light is installed on the outer wall of the detection frame. When the second button is triggered, the response light is constantly lit, and the second button is electrically connected to the logging device.

[0009] Preferably, the detection shaft has an internal cavity, and a rotating shaft is installed inside the cavity. A cover plate is fixedly installed at the bottom of the detection shaft, and the rotating shaft is rotatably connected to the cover plate. Multiple arc-shaped protrusions are fixedly installed on the rotating shaft, and each arc-shaped protrusion corresponds to an annular sleeve. A force-bearing shaft is also fixedly installed at one end of the moving shaft inside the annular sleeve, and a spring body is connected between the force-bearing shaft and the inner wall of the annular sleeve. One end of the force-bearing shaft penetrates the inner wall of the annular sleeve and extends into the cavity, and the force-bearing shaft is located on the movement trajectory of the arc-shaped protrusions.

[0010] Preferably, a limiting groove is provided on the detection shaft, and a knob is rotatably installed on the outer wall of the detection shaft. A connecting slider is fixedly installed on the inner wall of the knob. The connecting slider slides within the limiting groove. The connecting slider is fixedly connected to the rotating shaft by bolts, and a nut that is threadedly connected to the detection shaft is provided above the connecting slider.

[0011] Preferably, positioning sleeves are symmetrically installed on the outer wall of the limiting shaft, baffles are fixedly installed on the positioning sleeves, and steel columns are fixedly installed on the outer wall of the detection frame. The baffles contact the steel columns to limit the rotation direction of the detection frame.

[0012] Preferably, multiple steel sleeves are fixedly installed on the outer wall of the processing sleeve, and an extension shaft is fixedly installed on the scraper section. One end of the extension shaft passes through the outer wall of the steel sleeve and extends into its interior. A return spring is installed on the inner wall of the steel sleeve. The extension shaft is in contact with the return spring. A ball is embedded in the outer wall of the extension shaft, and an arc-shaped groove is opened on the inner wall of the steel sleeve. The ball slides within the arc-shaped groove.

[0013] Preferably, the processing unit includes an electromagnet disposed at the bottom of the processing sleeve, and a magnetic plate frame disposed above the electromagnet, and an arc-shaped guide plate is fixedly mounted on the magnetic plate frame. One end of the extension shaft contacts the surface of the arc-shaped guide plate, and a constant force spring is connected between the arc-shaped guide plate and the inner wall of the top of the processing sleeve.

[0014] Preferably, a torsion spring is connected between the detection frame and the moving shaft, and the torsion spring is sleeved on the limiting shaft.

[0015] Preferably, the diameter and number of teeth of the driven gear are both smaller than those of the driving gear.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] 1. This invention utilizes a roller, main shaft, driving gear, driven gear, transmission shaft, annular disc frame, sliding block, arc-shaped panel, and button 1. When the roller rolls on the well wall surface, the change in the main shaft speed is transmitted to the annular disc frame through transmission. The sliding block slides along the guide groove under the action of centrifugal force, so that the contact state between the arc-shaped panel and button 1 changes in real time with the roller speed. This enables reliable sensing of well wall deposits such as mud cake. After detecting mud cake, subsequent processing actions can be triggered in a timely manner, avoiding the absorption and scattering of acoustic signals by mud cake, and effectively improving the data quality of acoustic imaging detection.

[0018] 2. This invention monitors the interaction between the touch rod on the monitoring rod and the button two embedded in the inner wall of the top of the detection frame, as well as the electrical connection between the response light and the logging device. When the roller is displaced due to changes in well diameter or encountering pits in the well wall, the contact state between the touch rod and the button two changes, triggering the button two to send an electrical signal to the logging device. This enables real-time monitoring of changes in the geometric shape of the well wall, allowing the logging device to simultaneously acquire well wall status information. This provides a basis for the correction and interpretation of subsequent acoustic detection data, further ensuring the accuracy and reliability of acoustic imaging detection.

[0019] 3. This invention utilizes the coordinated operation of an electromagnet, magnetic plate frame, arc-shaped guide plate, extension shaft, ball bearings, and arc-shaped groove inside the processing sleeve. When the roller detects mud cake and the button is disconnected for more than a set threshold, the electromagnet is energized to drive the arc-shaped guide plate upward. The arc-shaped guide plate pushes the extension shaft towards the well wall and forces the ball bearings to slide along the arc-shaped groove, causing the scraper section to rotate from a near-vertical state to a near-horizontal state. Multiple scraper sections move closer to each other in the circumferential direction to form a complete annular coverage, achieving comprehensive scraping of mud cake from the well wall. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the measuring device of the present invention within the well body;

[0022] Figure 3 This is a schematic diagram of the shaft processing and detection structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the internal structure of the shaft tested according to the present invention;

[0024] Figure 5 This is a schematic diagram showing the separation of the knob and rotating shaft structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the internal structure of the annular sleeve of the present invention;

[0026] Figure 7 This is a schematic diagram of the moving shaft and detection frame structure of the present invention;

[0027] Figure 8 This is a schematic diagram of the internal structure of the detection frame of the present invention;

[0028] Figure 9 This is a schematic diagram of the detection frame and monitoring pole structure of the present invention;

[0029] Figure 10 This is a schematic diagram of the disassembly and assembly frame structure of the present invention;

[0030] Figure 11 This is a schematic diagram of the drive unit structure of the present invention;

[0031] Figure 12 This is a schematic diagram of the annular disk frame structure of the present invention;

[0032] Figure 13 This is a schematic diagram of the sleeve structure of the present invention;

[0033] Figure 14 This is a schematic diagram of the internal structure of the sleeve of the present invention;

[0034] Figure 15This is a schematic diagram of a partial internal structure of the steel sleeve of the present invention.

[0035] In the diagram: 1. Logging device; 2. Processing shaft; 3. Detection shaft; 31. Cavity; 32. Rotating shaft; 33. Cover plate; 34. Arc-shaped protrusion; 35. Limiting groove; 36. Knob; 37. Connecting slider; 38. Bolt; 39. Nut; 4. Annular sleeve; 5. Moving shaft; 51. Detection frame; 511. Spring mechanism; 512. Button 2; 513. Response light; 514. Steel column; 515. Torsion spring; 52. Limiting shaft; 521. Positioning sleeve; 522. Baffle; 53. Monitoring rod frame; 531. Contact rod frame; 54. Roller; 55. 56. Spindle; 57. Assembly / Disassembly Frame; 58. Annular Disc Frame; 59. Guide Groove; 50. Sliding Block; 51. Spring Unit; 52. Arc-shaped Panel; 53. Button 1; 54. Force-bearing Shaft; 55. Spring Body; 6. Drive Unit; 66. Drive Gear; 67. Driven Gear; 68. Transmission Shaft; 79. Processing Sleeve; 70. Steel Sleeve; 71. Return Spring; 72. Arc-shaped Groove; 80. Scraper Unit; 81. Extension Shaft; 82. Ball Bearing; 91. Processing Unit; 92. Electromagnet; 93. Magnetic Plate Frame; 94. Arc-shaped Guide Plate; 95. Constant Force Spring. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Please see Figure 1-15 This invention provides a technical solution: a downhole safety detection acoustic imaging logging mechanism, including a logging device 1, which is used to perform acoustic imaging detection operations downhole. A processing shaft 2 is fixedly installed at the bottom of the logging device 1, and a detection shaft 3 is fixedly installed at the bottom of the processing shaft 2. Multiple annular sleeves 4 are fixedly installed on the outer wall of the detection shaft 3. The multiple annular sleeves 4 are evenly distributed along the axial direction of the detection shaft 3. A movable shaft 5 is slidably installed inside each annular sleeve 4. One end of the movable shaft 5 passes through the inner wall of the annular sleeve 4 and extends to the outside of the annular sleeve 4. A detection frame 51 is provided at the end of the movable shaft 5 located outside the annular sleeve 4. A limiting shaft 52 is fixedly installed at one end of the movable shaft 5. The detection frame 51 is rotatably connected to the limiting shaft 52. A monitoring rod 53 is provided inside the detection frame 51. One end of the monitoring rod 53 passes through the inner wall of the detection frame 51 and extends to the outside of the detection frame 51.

[0038] A roller 54 is provided at one end of the monitoring rod 53 located outside the detection frame 51. The roller 54 is used to directly contact the well wall downhole and roll along the well wall. A main shaft 55 is fixedly installed on the roller 54, and the main shaft 55 is rotatably connected to the inner wall of the detection frame 51. A spring mechanism 511 is connected between the monitoring rod 53 and the inner wall of the detection frame 51. The spring mechanism 511 is used to provide elastic support force to the monitoring rod 53, so that the roller 54 can maintain close contact with the well wall under normal working conditions. A contact rod 531 is fixedly installed on the top of the monitoring rod 53. Button 2 512 is embedded in the inner wall of the top. Button 2 512 is located on the movement trajectory of the touch rod 531. Response light 513 is installed on the outer wall of the detection frame 51. When button 2 512 is triggered, response light 513 is constantly lit. Response light 513 is used to indicate on the ground or downhole whether the roller 54 has established a stable contact with the well wall, so that the staff can confirm that the instrument is in normal working condition. Button 2 512 is electrically connected to logging device 1. When the touch rod 531 is separated from button 2 512, button 2 512 transmits information to logging device 1 in the form of an electrical signal.

[0039] The detection shaft 3 has a cavity 31 inside, and a rotating shaft 32 is installed inside the cavity 31. A cover plate 33 is fixedly installed at the bottom of the detection shaft 3, and the rotating shaft 32 is rotatably connected to the cover plate 33. Multiple arc-shaped protrusions 34 are fixedly installed on the rotating shaft 32, and the arc-shaped protrusions 34 correspond one-to-one with the annular sleeve 4. A force-bearing shaft 59 is fixedly installed at one end of the movable shaft 5 inside the annular sleeve 4. A spring body 50 is connected between the force-bearing shaft 59 and the inner wall of the annular sleeve 4. One end of the force-bearing shaft 59 penetrates the inner wall of the annular sleeve 4 and extends into the cavity 31. 59 is located on the movement trajectory of the arc-shaped protrusion 34. A limit groove 35 is provided on the detection shaft 3. A knob 36 is rotatably installed on the outer wall of the detection shaft 3. A connecting slider 37 is fixedly installed on the inner wall of the knob 36. The connecting slider 37 slides within the limit groove 35. The connecting slider 37 is fixedly connected to the rotating shaft 32 by bolts 38. A nut 39 is provided above the connecting slider 37. The nut 39 is threadedly connected to the detection shaft 3. The nut 39 is used to lock the connecting slider 37 and the rotating shaft 32 to prevent the knob 36 from loosening after adjustment, which would cause the extension of the roller 54 to change.

[0040] A positioning sleeve 521 is symmetrically installed on the outer wall of the limiting shaft 52. A baffle 522 is fixedly installed on the positioning sleeve 521. A steel column 514 is fixedly installed on the outer wall of the detection frame 51. The baffle 522 contacts the steel column 514 to limit the rotation direction of the detection frame 51. By utilizing the contact between the baffle 522 and the steel column 514, it is ensured that the detection frame 51 can only rotate upward. This design facilitates the adjustment of the position of the roller 54 and avoids the roller 54 from being subjected to a large force and rotating downward, thereby affecting subsequent well wall detection. A torsion spring 515 is connected between the detection frame 51 and the moving shaft 5. The torsion spring 515 is sleeved on the limiting shaft 52.

[0041] A disassembly frame 56 is fixedly installed on one side of the monitoring rod frame 53. An annular disc frame 57 is set inside the disassembly frame 56. The main shaft 55 and the transmission shaft 63 are rotatably connected to the monitoring rod frame 53 through bearings. Multiple guide grooves 571 are provided on the annular disc frame 57. A sliding block 572 is slidably installed inside each guide groove 571. A spring part 573 is connected between the sliding block 572 and the inner wall of the guide groove 571. One end of the sliding block 572 is located outside the guide groove 571 and is fixedly installed with an arc-shaped panel 574. A button 58 is fixedly installed on the inner wall of the disassembly frame 56. The button 58 is located on the movement trajectory of the arc-shaped panel 574. The button 58 is an electronic component that records the disconnection time. When the disconnection time of the button 58 exceeds a certain threshold, the button 58 sends information to the logging device 1 in the form of an electrical signal. The logging device 1 controls subsequent actions according to the received signal. The annular disc frame 57 and the main shaft 55 are connected by a drive part 6.

[0042] Furthermore, the drive unit 6 includes a drive gear 61 and a driven gear 62 disposed inside the disassembly frame 56. The drive gear 61 is fixedly mounted on the main shaft 55, and the driven gear 62 meshes with the drive gear 61. The diameter and number of teeth of the driven gear 62 are smaller than those of the drive gear 61. A transmission shaft 63 is fixedly mounted on the driven gear 62. The transmission shaft 63 is rotatably connected to the inner wall of the disassembly frame 56, and the annular disc frame 57 is fixedly mounted on the end of the transmission shaft 63.

[0043] A processing sleeve 7 is fixedly mounted on the processing shaft 2. Multiple scraper sections 8 are provided on the outer wall of the processing sleeve 7. Multiple steel sleeves 71 are fixedly mounted on the outer wall of the processing sleeve 7, each corresponding to a scraper section 8. An extension shaft 81 is fixedly mounted on each scraper section 8. One end of the extension shaft 81 penetrates the outer wall of the steel sleeve 71 and extends into the interior of the steel sleeve 71. A return spring 72 is installed on the inner wall of the steel sleeve 71. The extension shaft 81 is in contact with the return spring 72. A ball bearing 82 is embedded in the outer wall of the extension shaft 81. An arc-shaped groove 73 is formed on the inner wall of the steel sleeve 71, and the ball bearing 82 rests in the arc-shaped groove. The inner limit sliding of the 73 is provided. The processing sleeve 7 is provided with a processing unit 9. The processing unit 9 is used to drive the scraper unit 8 to scrape off the mud cake on the well wall. The processing unit 9 includes an electromagnet 91 provided at the bottom of the processing sleeve 7. A magnetic plate frame 92 is provided above the electromagnet 91. An arc-shaped guide plate 93 is fixedly installed on the magnetic plate frame 92. One end of the extension shaft 81 is in contact with the surface of the arc-shaped guide plate 93. A constant force spring 94 is connected between the arc-shaped guide plate 93 and the inner wall of the top of the processing sleeve 7. The scraper on the scraper unit 8 is preferably made of silicone material to ensure that the scraper can undergo adaptive deformation when it comes into contact with the well wall, so as to fit tightly with the well wall.

[0044] Specifically, before conducting downhole safety inspections, the operator first rotates knob 36 at the wellhead. Since the connecting slider 37 on knob 36 is fixedly connected to the rotating shaft 32 via bolt 38, when knob 36 rotates, the connecting slider 37 slides within the limiting groove 35. The connecting slider 37 drives the rotating shaft 32 to rotate, and the arc-shaped protrusion 34 on the rotating shaft 32 applies force to the end of the force-bearing shaft 59. The force-bearing shaft 59 moves inside the annular sleeve 4 and compresses the spring body 50. The force-bearing shaft 59 drives the moving shaft 5 to move synchronously. The moving shaft 5, through the limiting shaft 52, drives the detection frame 51 to move synchronously. The monitoring rod 5 inside the detection frame 51... 3. Under the action of the spring mechanism 511, the detection frame 51 moves synchronously. The roller 54 at the end of the monitoring rod 53 contacts the well wall. Continue to rotate the knob 36 to make the detection frame 51 continue to move towards the well wall. After the roller 54 contacts the well wall, it is subjected to the reaction force of the well wall. The roller 54 controls the movement of the monitoring rod 53 inside the detection frame 51 and squeezes the spring mechanism 511 until the top of the monitoring rod 53 touches the button 531 and contacts the second button 512. At this time, the second button 512 is triggered and the response light 513 is constantly lit, indicating that the roller 54 has established a stable contact state with the well wall. Then, the logging device 1 is put into the well for acoustic imaging detection operation.

[0045] During the uniform descent of the logging device 1, the roller 54 remains in contact with the well wall and rolls along the well wall. Under the action of the spring mechanism 511, the monitoring rod 53 continuously presses the roller 54 against the well wall. When it encounters an area where the well diameter increases, under the elastic restoring force of the compressed spring mechanism 511, the monitoring rod 53 drives the roller 54 to extend towards the inner wall of the area where the well diameter increases. The roller 54 continues to maintain contact with the well wall, but the monitoring rod 53 moves outward relative to the detection frame 51. The contact rod 531 separates from the button 2 512, and the button 2 512 transmits information to the logging device 1 in the form of an electrical signal.

[0046] When encountering an area where the well diameter suddenly decreases, the reaction force of the well wall on the roller 54 increases, the monitoring rod 53 continues to drive the roller 54 to move into the detection frame 51, the spring mechanism 511 continues to compress, and the contact rod 531 also separates from the button 2 512. The button 2 512 transmits information to the logging device 1 in the form of an electrical signal.

[0047] When encountering an uneven well wall, the monitoring rod 53 repeatedly extends and retracts within the detection frame 51, and the rod 531 and button 512 intermittently contact and separate. Button 512 transmits information to the logging device 1 in the form of an electrical signal, thereby realizing real-time monitoring of changes in the geometry of the well wall.

[0048] When the roller 54 encounters a thick mud cake, due to the viscosity and high rolling resistance of the mud cake, the resistance experienced by the roller 54 when rolling on the surface of the mud cake is significantly greater than the resistance when rolling on the surface of the open hole well wall.

[0049] Under the condition that the logging device 1 is lowered at a constant speed and the driving force is constant, the roller 54 is subjected to increased rolling resistance, and its rolling speed decreases accordingly. The rotation speed of the main shaft 55 also decreases. At the same time, due to the thickness of the mud cake, the roller 54 will be displaced upward under the action of the mud cake. The roller 54 drives the detection frame 51 to rotate on the limiting shaft 52 through the monitoring rod 53. The torsion spring 515 is deformed and twisted. When the detection frame 51 rotates, the monitoring rod 53 will retract during the angle adjustment process. The contact rod 531 separates from the button 2 512. The button 2 512 transmits information to the logging device 1 in the form of an electrical signal.

[0050] When the main shaft 55 rotates, it drives the drive gear 61 to rotate synchronously. The drive gear 61 meshes with the driven gear 62 to rotate, and the driven gear 62 drives the transmission shaft 63 to rotate. The transmission shaft 63 drives the annular disc frame 57 to rotate synchronously. When the annular disc frame 57 rotates, the sliding block 572 in the guide groove 571 slides outward along the guide groove 571 under the action of centrifugal force. The spring part 573 is stretched, and the sliding block 572 drives the arc panel 574 to move towards the button 58. In the normal wellbore path, the button 58 will be triggered by the arc panel 574. When the roller 54 encounters a thick mud cake, the speed of the main shaft 55 decreases, the centrifugal force on the arc panel 574 decreases, and the button 58 will not be triggered and will be in the disconnected state. The button 58 is an electronic component that records the disconnection time. When the disconnection time of the button 58 exceeds a certain threshold, the button 58 sends the information to the logging device 1 in the form of an electrical signal. The logging device 1 controls the electromagnet 91 to be energized.

[0051] Specifically, when the mud cake is thick, the roller 54 slows down due to the mud cake's effect. Furthermore, the increased thickness of the mud cake causes the monitoring rod 53 to travel a greater distance into the detection frame 51, causing it to contact the button 531 and separate from the second button 512. Both buttons 58 and 512 are in the off state. At this time, the logging device 1 immediately controls the electromagnet 91 to be energized. When the mud cake is thin but long, although the thickness at a single point is thin, the long length means that the acoustic signal is continuously attenuated along a longer path. The cumulative effect will affect the imaging quality. The movement of the roller 54... When the moving distance is small, the contact rod 531 has not yet separated from the button 2 512, but the roller 54 is continuously subjected to increased rolling resistance on the longer mud cake section, and the rotation speed of the main shaft 55 remains low for a long time. After the disconnection time of the button 1 58 exceeds a certain threshold, the logging device 1 controls the electromagnet 91 to be energized to scrape off the mud cake. When the mud cake is thin and short, the rolling time of the roller 54 on the mud cake section is short, and the disconnection time of the button 1 58 is short, indicating that the mud cake has a limited degree of interference with the acoustic detection and no interference is required. The logging device 1 does not control the electromagnet 91 to be energized.

[0052] When the logging device 1 controls the electromagnet 91 to be energized, the electromagnet 91 generates a repulsive force on the magnetic plate frame 92. The magnetic plate frame 92 drives the arc-shaped guide plate 93 to move upward. The arc-shaped guide plate 93 compresses the constant force spring 94. During the upward movement, the arc-shaped guide plate 93 applies a force to the end of the extension shaft 81, causing the extension shaft 81 to drive the scraper part 8 to move towards the well wall. The extension shaft 81 compresses the return spring 72. When the extension shaft 81 moves towards the well wall, the ball bearings 82 on the outer wall of the extension shaft 81 slide along the trajectory of the arc-shaped groove 73. Since the arc-shaped groove 73 has an arc-shaped direction, when the ball bearings 82 slide in the arc-shaped groove 73, they cause the extension shaft 81 and the scraper part 8 to deflect at an angle.

[0053] Initially, the scraper section 8 is placed in a nearly vertical position. As the extension shaft 81 moves further toward the well wall, the ball bearing 82 slides along the arc-shaped groove 73, and the scraper section 8 rotates from a nearly vertical position to a nearly horizontal position. Since the angles of multiple scraper sections 8 are adjusted and they are evenly distributed around the circumference of the processing sleeve 7, when each scraper section 8 rotates to a nearly horizontal position, they move closer to each other in the circumferential direction, thus covering the entire circumferential surface of the well wall. This allows for a comprehensive removal of mud cake from the entire circumferential surface of the well wall. The scrapers on the scraper section 8 are preferably made of silicone material. When the silicone scraper comes into contact with the well wall, it can undergo adaptive deformation, ensuring that the scraper fits tightly against the well wall, improving the scraping effect while avoiding damage to the well wall.

[0054] After roller 54 passes through the mud cake area, the resistance from the mud cake disappears. Under the elastic restoring force of spring mechanism 511, monitoring rod 53 drives roller 54 back to its normal working position. The contact rod 531 re-engages with button 512, and button 512 returns to its triggered state. Simultaneously, under the elastic restoring force of torsion spring 515, detection frame 51 returns to its initial rotational position; the rotational speed of main shaft 55 returns to normal, the rotational speeds of drive gear 61 and driven gear 62 return to normal, the rotational speed of annular disc frame 57 returns to normal, and the sliding block 572, under centrifugal force... The device moves back towards button 58, triggering button 58 on the arc panel 574, which then returns to its closed state. After the electromagnet 91 is de-energized, the arc guide plate 93 drives the magnetic plate frame 92 to descend and reset under the elastic restoring force of the constant force spring 94. The extension shaft 81, under the elastic restoring force of the reset spring 72, drives the scraper section 8 to rotate from a near-horizontal state to a near-vertical state and retracts. The ball bearing 82 slides in the opposite direction along the arc groove 73, and the scraper section 8 returns to its initial near-vertical state. The entire mechanism completes its reset, preparing for the next section of well wall exploration.

[0055] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A downhole safety detection acoustic imaging logging mechanism, characterized in that, The device includes a logging device (1), a processing shaft (2) installed at the bottom of the logging device (1), and a detection shaft (3) fixedly installed at the bottom of the processing shaft (2). Multiple annular sleeves (4) are fixedly installed on the outer wall of the detection shaft (3). A movable shaft (5) is slidably installed inside each annular sleeve (4). One end of the movable shaft (5) passes through the inner wall of the annular sleeve (4) and extends to the outside. A detection frame (51) is also provided at the end of the movable shaft (5) located outside the annular sleeve (4). A limiting shaft (52) is fixedly installed at one end of the movable shaft (5). The detection frame (51) is rotatably connected to the limiting shaft (52). A monitoring rod frame (53) is provided inside the detection frame (51). One end of the monitoring rod (53) penetrates the inner wall of the detection frame (51) and extends to the outside. A roller (54) is also provided at the end of the monitoring rod (53) located outside the detection frame (51). A main shaft (55) that is rotatably connected to the inner wall of the detection frame (51) is fixedly installed on the roller (54). A disassembly frame (56) is fixedly installed on one side of the monitoring rod (53), and an annular disc frame (57) is provided inside the disassembly frame (56). Multiple guide grooves (571) are also provided on the annular disc frame (57). A sliding block (572) is slidably installed inside each guide groove (571). The sliding block (572) and the guide groove (571) are connected. 1) A spring part (573) is connected between the inner walls. One end of the sliding block (572) is located outside the guide groove (571) and is fixedly installed with an arc panel (574). A button (58) is fixedly installed on the inner wall of the disassembly frame (56). The button (58) is located on the movement trajectory of the arc panel (574). The annular disc frame (57) and the main shaft (55) are connected by a drive part (6). A processing sleeve (7) is fixedly installed on the processing shaft (2). Multiple scraper parts (8) are provided on the outer wall of the processing sleeve (7). A processing part (9) for driving the scraper to scrape the mud cake on the well wall is provided inside the processing sleeve (7).

2. The acoustic imaging logging mechanism for downhole safety detection according to claim 1, characterized in that: The drive unit (6) includes a drive gear (61) disposed inside the disassembly frame (56), the drive gear (61) being fixedly mounted on the main shaft (55), and a driven gear (62) disposed inside the disassembly frame (56), the driven gear (62) meshing with the drive gear (61), a transmission shaft (63) being fixedly mounted on the driven gear (62), the transmission shaft (63) being rotatably connected to the inner wall of the disassembly frame (56), and an annular disc frame (57) being fixedly mounted on the end of the transmission shaft (63).

3. The acoustic imaging logging mechanism for downhole safety detection according to claim 2, characterized in that: A spring mechanism (511) is connected between the monitoring rod (53) and the inner wall of the detection frame (51), and a touch rod (531) is fixedly installed on the top of the monitoring rod (53). A button (512) is embedded in the inner wall of the top of the detection frame (51). The button (512) is located on the movement trajectory of the touch rod (531), and a response light (513) is installed on the outer wall of the detection frame (51). When the button (512) is triggered, the response light (513) is constantly lit. The button (512) is electrically connected to the logging device (1).

4. The acoustic imaging logging mechanism for downhole safety detection according to claim 3, characterized in that: The detection shaft (3) has a cavity (31) inside, and a rotating shaft (32) is set inside the cavity (31). A cover plate (33) is fixedly installed at the bottom of the detection shaft (3). The rotating shaft (32) is rotatably connected to the cover plate (33). Multiple arc-shaped protrusions (34) are fixedly installed on the rotating shaft (32). The arc-shaped protrusions (34) correspond one-to-one with the annular sleeve (4). A force-bearing shaft (59) is also fixedly installed at one end of the moving shaft (5) inside the annular sleeve (4). A spring body (50) is connected between the force-bearing shaft (59) and the inner wall of the annular sleeve (4). One end of the force-bearing shaft (59) penetrates the inner wall of the annular sleeve (4) and extends into the cavity (31). The force-bearing shaft (59) is located on the movement trajectory of the arc-shaped protrusions (34).

5. The acoustic imaging logging mechanism for downhole safety detection according to claim 4, characterized in that: A limiting groove (35) is provided on the detection shaft (3), and a knob (36) is rotatably installed on the outer wall of the detection shaft (3). A connecting slider (37) is fixedly installed on the inner wall of the knob (36). The connecting slider (37) slides within the limiting groove (35). The connecting slider (37) is fixedly connected to the rotating shaft (32) by bolts (38), and a nut (39) that is threadedly connected to the detection shaft (3) is provided above the connecting slider (37).

6. The acoustic imaging logging mechanism for downhole safety detection according to claim 1, characterized in that: A positioning sleeve (521) is symmetrically installed on the outer wall of the limiting shaft (52). A baffle (522) is fixedly installed on the positioning sleeve (521), and a steel column (514) is fixedly installed on the outer wall of the detection frame (51). The baffle (522) contacts the steel column (514) to limit the rotation direction of the detection frame (51).

7. The acoustic imaging logging mechanism for downhole safety detection according to claim 1, characterized in that: Multiple steel sleeves (71) are fixedly installed on the outer wall of the processing sleeve (7). An extension shaft (81) is fixedly installed on the scraper part (8). One end of the extension shaft (81) passes through the outer wall of the steel sleeve (71) and extends into its interior. A return spring (72) is installed on the inner wall of the steel sleeve (71). The extension shaft (81) and the return spring (72) are in contact. A ball (82) is embedded in the outer wall of the extension shaft (81). An arc-shaped groove (73) is opened on the inner wall of the steel sleeve (71). The ball (82) slides within the arc-shaped groove (73).

8. The acoustic imaging logging mechanism for downhole safety detection according to claim 7, characterized in that: The processing unit (9) includes an electromagnet (91) disposed at the bottom of the processing sleeve (7), and a magnetic plate frame (92) disposed above the electromagnet (91). An arc-shaped guide plate (93) is fixedly mounted on the magnetic plate frame (92). One end of the extension shaft (81) contacts the surface of the arc-shaped guide plate (93). A constant force spring (94) is connected between the arc-shaped guide plate (93) and the inner wall of the top of the processing sleeve (7).

9. A downhole safety detection acoustic imaging logging mechanism according to claim 3, characterized in that: A torsion spring (515) is connected between the detection frame (51) and the moving shaft (5), and the torsion spring (515) is sleeved on the limiting shaft (52).

10. A downhole safety detection acoustic imaging logging mechanism according to claim 2, characterized in that: The diameter and number of teeth of the driven gear (62) are smaller than those of the driving gear (61).

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