Underground visual electric control guiding method and device

Abstract

The invention discloses an underground visual electric control guiding method and device. The underground visual electric control guiding device comprises an imaging short section, a deflecting short section, a rotating short section, a flexible short section and a control short section which are sequentially connected. The imaging pup joint is used for collecting underground video images and coding and storing data collected by the imaging pup joint; the deflecting short section and the rotating short section are used for providing a rotating angle when the logging instrument is guided into a target branch well; the flexible short section is used for providing a bending angle of the logging instrument; and the control short section is used for controlling the rotating angles of the inclined short section and the rotating short section and transmitting a video acquired by the imaging short section to the ground so as to realize real-time observation. According to the method, the electronic control rotary guiding technology and the visual guiding technology are adopted, identification and guiding entering of the target branch well hole are achieved, a solution thought is provided for identification and guiding entering of the branch well, the success rate of the operation that a logging tool enters the target well hole is increased, and therefore the logging efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of downhole visual logging, and in particular to a downhole visual electric-controlled steering method and device. Background Art

[0002] In recent years, multi-branch well technology has been widely used in oil and gas field development, especially in complex geological conditions such as low permeability, tight oil reservoirs, heavy oil reservoirs, and fault block reservoirs. By drilling multiple branch wellbores in a well, the single well production can be significantly increased, achieving "fewer wells, higher production", thereby improving the ultimate recovery rate.

[0003] However, as a new drilling and completion technology, multilateral wellbore technology presents certain difficulties in re-entering the target branch wellbore during post-casing logging. This means that after the logging instrument is lowered into the well, traditional tools cannot observe the target wellbore and cannot accurately identify it. Furthermore, the casing windows in multilateral wells may have steps or deformations, making it difficult for the logging instrument to flexibly adjust its angle, resulting in logging instrument obstruction.

[0004] Publication No. CN108643838A describes a downhole adjustable steerable drilling tool that includes a device for adjusting the bending of a downhole drilling tool assembly. While this device can adjust the drilling tool angle within a small range, it cannot detect whether the logging tool has re-entered the target wellbore. This invention addresses the issue of logging tools re-entering the target branch wellbore. Summary of the Invention

[0005] In order to overcome the defects of the above-mentioned existing technologies, the purpose of the present invention is to provide a downhole visual electric-controlled guidance method and device. The device adopts electric-controlled rotary guidance technology and visual guidance technology to realize the identification and guidance of the target branch wellbore, providing a solution for the identification and introduction of branch wells, improving the success rate of logging tools entering the target wellbore, and thus improving logging efficiency.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A downhole visual electric-controlled steering device includes an imaging sub 1, a deflecting sub 2, a rotating sub 3, a flexible sub 4, and a control sub 5, which are connected in sequence.

[0008] The imaging sub 1 and the deflecting sub 2 are connected by threads, the deflecting sub 2 and the rotating sub 3 are connected by threads, the rotating sub 3 and the flexible sub 4 are connected by threads, and the flexible sub 4 and the control sub 5 are connected by threads.

[0009] The imaging subsection 1 is used to collect downhole video images and encode and store the collected data of the imaging subsection 1;

[0010] The deflecting sub 2 and the rotating sub 3 are used to provide the rotation angle of the logging instrument when it is introduced into the target branch wellbore;

[0011] The flexible sub 4 is used to provide a bending angle for the logging instrument;

[0012] The control subsection 5 is used to control the rotation angles of the deflecting subsection 2 and the rotating subsection 3, and transmit the video collected by the imaging subsection 1 to the ground to achieve real-time observation.

[0013] The imaging short section 1 includes a high-temperature resistant ultra-wide-angle high-definition camera 1-1 inside, which is used to collect video information. The rear end of the high-definition camera 1-1 is fixed on the camera seat 1-2, and the front end of the high-definition camera 1-1 is installed with an LED lighting system 1-3, which provides light for the high-definition camera. A perspective pressure-bearing component 1-4 is set at the front end of the high-definition camera 1-1, and a line skeleton 1-5 is installed at the rear end of the camera seat 1-2. A power module 1-6, a data acquisition coding board 1-7 and a main control unit 1-8 are installed on the line skeleton 1-5; the outer end of the line skeleton 1-5 is installed with an imaging short section shell 1-9.

[0014] The power modules 1-6 provide voltage for the LED lighting system, the data acquisition encoding board 1-7, and the main control unit 1-8;

[0015] The data acquisition coding board 1-7 has a video coding function, which encodes the video data collected by the high-definition camera 1-1 and outputs it through a network cable, forming an underground visual system.

[0016] The exterior of the deflecting sub 2 includes a spherical housing 1 2-1, a spherical housing 2-7 and a motor housing 2-9 which are connected in sequence;

[0017] The spherical shell 2-1 and the motor shell 2-9 are connected by threads. There is a motor 2-10 inside the motor shell 2-9. The motor 2-10 is installed on the motor bracket 2-11. The motor encoder 2-12 is installed on the motor bracket 2-11. The output shaft of the motor 2-10 is connected to one end of the universal coupling 2-8. The other end of the universal coupling 2-8 is connected to the transmission shaft 2-4. The transmission shaft 2-4 is equipped with a key 2-3. The key 2-3 is connected to the spherical shell 2-1. When the control short section 5 sends an instruction to control the rotation of the motor, the transmission shaft 2-4 drives the spherical shell 2-1 to rotate. The front end of the inclination short section 2 is connected to the imaging short section 1, so it drives the imaging short section 1 to rotate.

[0018] The external part of the rotating short section 3 has a motor housing 2 3-11, which is connected to the bearing seat 3-10 by a threaded connection. The internal part of the motor housing 2 3-11 has a motor 3-9. The output shaft of the motor 3-9 is connected to one end of the rotating shaft 3-5. The other end of the rotating shaft 3-5 is connected to the rotating body 3-2 and is locked with a locking nut 3-1. Deep groove balls 3-8 and deep groove balls 3-12 are installed on the rotating shaft 3-5. Thrust ball bearings 3-6 and thrust ball bearings 3-7 are installed on the rotating shaft 3-5. There is a circuit skeleton 3-13 inside the shell 3-11, and a high-precision IMU phase sensor 3-14 and a motor encoder 3-15 are installed on the circuit skeleton 3-13. The high-precision IMU phase sensor 3-14 is used to accurately measure the attitude, position and motion state of the instrument. The motor encoder 3-15 is used to control the rotation angle of the motor. When the control short section 5 receives an instruction from the ground, the control motor 3-9 rotates, thereby rotating the rotating shaft 3-5 and the rotating body 3-2, driving the deflection short section 2 and the front imaging short section 1 to rotate.

[0019] The flexible short section 4 has a flexible body 4-1, an upper joint 4-2 and a lower joint 4-3. One end of the flexible body 4-1 is connected to the upper joint 4-2 by a thread, and the other end of the flexible body 4-1 is connected to the lower joint 4-3 by a thread; there is a gap between the flexible sections 4-1-1 on the flexible body, and the flexible body 4-1 can adjust the bending angle.

[0020] A downhole visual electric-controlled guidance method comprises the following steps:

[0021] The rotating sub 3 has an integrated motor encoder 3-15 and a high-precision IMU phase sensor 3-14, and the deflecting sub 2 has an integrated motor encoder 2-12. The imaging sub 1 visual system and the ground horizontal line are used for attitude compensation and superposition, thereby guiding the tool string into the target wellbore.

[0022] The specific steps are as follows:

[0023] Step 1: Before going down the well, the instrument string completes the attitude calibration:

[0024] After the deflection sub 2 is returned to its original position, the instrument string is in an axially straight state. Before being lowered into the well, the instrument string undergoes attitude calibration: a high-precision IMU phase sensor 3-14 is installed on the fixed frame inside the rotating sub 3. After the deflection sub 2 is returned to its original position and the entire connection is completed, attitude compensation is performed with the ground horizontal line through the imaging sub 1 visual system. The calibration reference is the positive direction of the video image observed by the naked eye. At this time, the roll angle compensation value Ang0 is recorded relative to the horizontal plane. The gravity direction is defined as 0°. The clockwise angle increases, 360° coincides with 0°, and directly above is 180°.

[0025] Step 2: Lower the instrument to the branch wellbore:

[0026] When the tool string is lowered to the imaging sub and the target branch wellbore is observed (about 30 cm is the distance at which the downhole target can be observed more clearly), slowly advance the tool string until the front end is roughly flush with the upper edge of the target branch wellhead.

[0027] Step 3: Obtain branch well images and overlay them:

[0028] The downhole vision system acquires the branch well image PicX, and the high-precision IMU phase sensor acquires real-time roll angle data rollX. The video image information is uploaded to the surface host software. After superimposing rollX angle compensation on PicX, the surface software calculates the actual angle AngX of the branch wellhead relative to the gravity direction based on image feature analysis. The software then controls the rotation of the rotating sub to the corresponding angle to align the incline surface with the branch wellbore.

[0029] Step 4: Rotate the deflection sub 2 and guide it into the branch well:

[0030] From step three, we know that the bevel surface rotates to the branch well position. The motor 2-10 in the bevel sub drives the spherical housing 1 2-1 to rotate relative to the spherical housing 2 2-7 via the coupling 2-8. The bevel angle α is used to make the deflection angle β cover the range of 0–2α, so that the axis of the bevel surface is aligned with the branch wellhead. Finally, based on the geometric relationship between the length L of the imaging sub 1 and the deflection angle, D = L × tan(2α), the end rotation diameter trajectory is generated.

[0031] Step 5: Instrument adjustment after entering the branch well:

[0032] After the rotating sub 3 drives the deflecting direction to align with the target branch wellbore, the deflecting sub 2 fine-tunes the angle in conjunction with the real-time video to guide the front end of the instrument into the target branch wellbore. At the same time, the flexible sub 4 compensates for the change in wellbore curvature. After the deflecting sub 2 is fully inserted, the sub gradually rotates back to its original position, and finally the entire instrument string enters the target branch wellbore.

[0033] The calculation formula in step 3 is as follows:

[0034] AngX=Picx-rollX;

[0035] Taking the actual working condition as an example: when rollX = 30°, the current branch well image information PicX temporarily takes the gravity direction as 0°. The software calculates the branch wellhead angle of the image PicX to be 270°. After compensation, the actual angle is 240°, that is, 270°-30°.

[0036] At this time, the rotating short section is controlled to rotate clockwise 60°, 240°-180°. Specifically, the motor 3-9 drives the rotating shaft 3-4, driving the deflecting short section and the imaging short section to rotate as a whole; that is, the deflecting short section's deflecting surface rotates 60°.

[0037] In the step 4, the deflection angle covers the range of 0–2α;

[0038] When the spherical shell 1 2 - 1 and the spherical shell 2 - 7 are in a straight line, the deflection angle β = α - α, that is, 0°;

[0039] When the spherical shell 1 2 - 1 and the spherical shell 2 - 7 are at the maximum angle, the deflection angle β=α+α, that is, 2α.

[0040] Beneficial effects of the present invention:

[0041] After logging instruments are lowered into the well, traditional tools are unable to observe or accurately identify the target wellbore. Furthermore, the casing windows of multi-branch wells may have steps or deformations, preventing the logging instruments from flexibly adjusting their angles and causing them to encounter obstructions. This device integrates a downhole vision system within the imaging sub, and a motor control system and high-precision IMU phase sensors within the rotating and deflecting subs. By performing attitude compensation with the ground horizontal line using the downhole vision system and high-precision IMU phase sensors, the rotation angle of the rotating sub is calculated to control the tool's steering. This enables the identification and guidance of target branch wellbores downhole.

[0042] The device of this invention solves the problems of traditional downhole tools being invisible and uncontrollable, and addresses the issue of logging tools repeatedly attempting to re-enter multilateral wells but failing to do so. This reduces obstruction encountered by downhole tools, improving both the success rate and efficiency of operations. This device can also connect more logging instruments, acquiring more data. This device enables intelligent, motorized, and precise control of downhole instruments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a functional block diagram of the present invention.

[0044] Figure 2 This is a connection diagram of the instrument of the present invention.

[0045] Figure 3 This is a system block diagram of the present invention.

[0046] Figure 4 This is a structural diagram of the imaging short section of the present invention.

[0047] Figure 5 This is a structural diagram of the deflection short section of the present invention.

[0048] Figure 6 This is a structural diagram of the rotating short section of the present invention.

[0049] Figure 7 This is a structural diagram of the flexible short section of the present invention.

[0050] Figure 8 Schematic diagram of the relative position of the target branch wellbore of the present invention.

[0051] Figure 9 This is an enlarged schematic diagram of the relative position of the target branch wellbore of the present invention.

[0052] Figure 10 This is the maximum trajectory of the inclination short section of the present invention.

[0053] Figure 11 This is a diagram illustrating the deflection angle β of the present invention. DETAILED DESCRIPTION

[0054] The present invention will be described in further detail below with reference to the accompanying drawings.

[0055] like Figure 1 As shown, a downhole visual electric control steering device includes a host computer software, a ground control system and a visual electric control steering tool;

[0056] The host computer software and the ground control system are connected and transmitted using a network cable, and the ground control system and the visual electronic control guidance tool are transmitted using an armored cable.

[0057] like Figure 2 As shown, the visualized electronically controlled steering tool includes an imaging subsection 1, a deflecting subsection 2, a rotating subsection 3, a flexible subsection 4, and a control subsection 5, which are connected in sequence;

[0058] The imaging subsection 1 and the deflecting subsection 2 are connected by threads, the deflecting subsection 2 and the rotating subsection 3 are connected by threads, the rotating subsection 3 and the flexible subsection 4 are connected by threads, and the flexible subsection 4 and the control subsection 5 are connected by threads.

[0059] The imaging subsection 1 is used to collect downhole video images and encode and store the collected data of the imaging subsection 1;

[0060] The deflecting sub 2 and the rotating sub 3 are used to provide the rotation angle of the logging instrument when it is introduced into the target branch wellbore;

[0061] The flexible sub 4 is used to provide a bending angle for the logging instrument;

[0062] The control subsection 5 is used to control the rotation angles of the deflecting subsection 2 and the rotating subsection 3, and transmit the video collected by the imaging subsection 1 to the ground to achieve real-time observation.

[0063] like Figure 4As shown, the interior of the imaging subsection is provided with a high-temperature resistant ultra-wide-angle high-definition camera 1-1, which is used to collect video information and is fixed on a camera seat 1-2. An LED lighting system 1-3 is installed at the front end of the high-definition camera to provide light for the high-definition camera. The external front end of the high-definition camera has a perspective pressure-bearing component 1-4, and a line skeleton 1-5 is installed behind the camera seat. A power module 1-6, a data acquisition coding board 1-7, and a main control unit 1-8 are installed on the line skeleton. An imaging subsection shell 1-9 is installed at the outer end of the line skeleton. The power module provides voltage to the LED lighting system, the data acquisition coding board and the main control unit. The data acquisition coding board has a video coding function, which encodes the video data collected by the camera and outputs it through a network cable, forming an underground visual system;

[0064] like Figure 5 As shown, the deflection sub has a spherical housing 1 (2-1), a spherical housing 2 (2-7), and a motor housing 2-9. Spherical housing 1 (2-1) and motor housing 2-9 are connected by threads. Motor housing 2-9 houses a motor. Motor 2-10 is mounted on a motor bracket 2-11. A motor encoder 2-12 is mounted on motor bracket 2-11. The motor output shaft is connected to a universal joint 2-8. The other end of universal joint 2-8 is connected to a drive shaft 2-4. A key 2-3 is mounted on the drive shaft and connected to spherical housing 1 (2-1). When the control sub issues a command to control the motor's rotation, the drive shaft drives spherical housing 1 to rotate. The front end of the deflection sub is connected to the imaging sub, driving the imaging sub's rotation.

[0065] The rotating subsection has a motor housing 3-11 on the outside, which is threadedly connected to the bearing seat 3-10. The motor housing contains a motor 3-9. The motor output shaft is connected to the rotating shaft 3-5, and the other end of the rotating shaft is connected to the rotating body 3-2 and locked with a lock nut 3-1. Deep groove balls 3-8 and 3-12 are installed on the rotating shaft to support the rotating parts and reduce frictional resistance. Thrust ball bearings 3-6 and 3-7 are installed on the rotating shaft to withstand axial force, limit axial displacement, and reduce friction. The motor housing has a circuit skeleton 3-13 on the inside, and a high-precision IMU phase sensor 3-14 and a motor encoder 3-15 are installed on the circuit skeleton. The high-precision IMU phase sensor is used to accurately measure the instrument's attitude, position, and motion state, and the motor encoder is used to control the motor's rotation angle. When the control subsection receives a command from the ground, it controls the motor to rotate, thereby rotating the rotating shaft and rotating body, driving the deflection subsection and the front-end imaging subsection to rotate.

[0066] like Figure 7 The flexible short section shown in the figure adopts a scalene structure on the outside, has a large flexibility, provides a bending angle in the tool, and makes the device have better passability and flexibility in the branch well.

[0067] The control sub, which includes a signal transmission unit and power module, is responsible for collecting video data, encoding, modulating, transmitting, and controlling communications. It is key hardware for enabling real-time data exchange between the underground and surface areas. The control sub performs functions such as data acquisition and integration, signal modulation and encoding, and real-time data transmission. It uploads compressed data to the surface system via a cable and simultaneously receives commands transmitted from the surface.

[0068] like Figures 8-11 As shown, a downhole visual electric control guidance method includes the following steps:

[0069] The specific steps are as follows:

[0070] Step 1: Complete the attitude calibration of the instrument string before going down the well

[0071] After the deflection sub is returned to its original position, the instrument string is in an axially straight position. Before being lowered into the well, the instrument string undergoes attitude calibration: a high-precision IMU phase sensor is installed on the fixed frame inside the rotating sub. After the deflection sub is returned to its original position and the entire connection is completed, attitude compensation is performed with the ground horizontal line through the imaging sub's visual system. The calibration benchmark is based on the positive direction of the video image observed with the naked eye. At this time, the roll angle compensation value Ang0 is recorded. Relative to the horizontal plane, the direction of gravity is defined as 0°, and the angle increases clockwise, 360° coincides with 0°, and directly above is 180°. All subsequent downhole video images are subjected to real-time roll angle compensation using the instrument's internal algorithm to ensure that the image content accurately corresponds to the Earth's gravity coordinate system.

[0072] Step 2: Lower the instrument to the branch well

[0073] When the instrument string is lowered to the point where the forward-looking wide-angle system observes a branch wellhead about 30 cm in front, it is slowly advanced until the front end of the instrument string passes over the upper edge of the wellhead but has not completely passed through the lower edge.

[0074] Step 3: Obtain branch well images and overlay them

[0075] Synchronously acquire the branch well image PicX and the IMU's real-time roll angle data rollX, and upload the video image information to the ground host software. After superimposing rollX angle compensation on PicX, the ground software calculates the actual angle AngX of the branch wellhead relative to the gravity direction based on image feature analysis, providing a precise positioning benchmark for subsequent well logging. The formula is as follows:

[0076] AngX=Picx-rollX;

[0077] Taking the actual working condition as an example: when rollX = 30°, the current branch well image information PicX temporarily takes the gravity direction as 0°. The software calculates the branch wellhead angle of the image PicX to be 270°. After compensation, the actual angle is 240°, that is, 270°-30°.

[0078] At this time, the rotating sub is controlled to rotate clockwise 60°, 240°-180°. Specifically, the motor 3-9 drives the rotating shaft 3-4, driving the deflecting sub and the imaging sub to rotate as a whole; that is, the deflecting sub rotates 60°.

[0079] Step 4: Rotate the deflection sub and guide it into the branch well

[0080] From step 3, we can see that the bevel is rotated to the branch well position. The motor 2-10 in the bevel sub drives the spherical shell 1 2-1 to rotate relative to the spherical shell 2 2-7 through the coupling 2-8. The bevel angle α is used to make the deflection angle β cover the range of 0–2α, so that the axis of the bevel is aligned with the branch well head. Finally, according to the geometric relationship between the length L of the imaging sub and the deflection angle, D = L × tan (2α), the end rotation diameter trajectory is generated. Figure 8 shown.

[0081] like Figure 9 As shown, the deflection angle β covers the following range:

[0082] When the spherical shell 1 and the spherical shell 2 are in a straight line, the deflection angle β=α-α, that is, 0°.

[0083] When the spherical shell 1 and the spherical shell 2 are at the maximum angle, the deflection angle is β=α+α, that is, 2α.

[0084] Step 5: Instrument adjustment after entering the branch well:

[0085] After the rotating short sub drives the deflection direction to align with the target branch wellbore, the deflection short sub fine-tunes the angle in conjunction with the real-time video to guide the front end of the instrument to slide into the target branch wellbore. At the same time, the flexible short sub dynamically compensates for the change in wellbore curvature through the unicorn structure. After the deflection short sub is fully entered, the short sub gradually rotates back to its position, and finally the entire section of the instrument string enters the target branch wellbore.

[0086] The device of this invention combines a downhole vision system with an electronically controlled steering method. Using a high-precision attitude and phase sensor, it accurately controls the rotation angle, enabling the selection of target branch wellbores. This solves the problem of traditional downhole tools being invisible and uncontrollable, improving both operational success rates and efficiency. This device can also connect to more logging instruments, such as sonic and gamma logging tools, to obtain more data. This device enables intelligent, motorized, and precise control of downhole instruments.

[0087] The present invention combines the protection visualization sub with the deflection sub to achieve visual control and guide the operating tool to the target wellbore.

[0088] The design method of the protection deflection short section structure of the present invention is not limited to the method mentioned in the article.

[0089] The present invention protects a control method for a visualization vision system and an attitude phase sensor IMU unit.

[0090] The present invention protects the connection and combination relationship of each part of the device. Each part of the device is independently designed and can be freely combined. Related instruments can be connected according to actual needs to obtain more downhole data.

Claims

1. A downhole visual electric control guidance device, characterized in that: It includes an imaging short section (1), a deflecting short section (2), a rotating short section (3), a flexible short section (4), and a control short section (5) which are connected in sequence; The imaging subsection (1) is used to collect downhole video images, and the data collected by the imaging subsection (1) is encoded and stored; The deflection sub (2) and the rotation sub (3) are used to provide the rotation angle of the logging instrument when it is introduced into the target branch wellbore; The flexible sub (4) is used to provide a bending angle for the well logging instrument; The control short section (5) is used to control the rotation angles of the deflecting short section (2) and the rotating short section (3), and transmit the video collected by the imaging short section (1) to the ground to achieve real-time observation.

2. The downhole visual electric control guidance device according to claim 1, characterized in that: The imaging subsection (1) includes a high-temperature resistant ultra-wide-angle high-definition camera (1-1) inside, the high-definition camera (1-1) is used to collect video information, the rear end of the high-definition camera (1-1) is fixedly mounted on the camera seat (1-2), the front end of the high-definition camera (1-1) is equipped with an LED lighting system (1-3), the LED lighting system (1-3) provides light for the high-definition camera, the front end of the high-definition camera (1-1) is provided with a perspective pressure-bearing component (1-4), the rear end of the camera seat (1-2) is equipped with a circuit skeleton (1-5), the circuit skeleton (1-5) is equipped with a power module (1-6), a data acquisition encoding board (1-7) and a main control unit (1-8), and the outer end of the circuit skeleton (1-5) is equipped with an imaging subsection housing (1-9); The power module (1-6) provides voltage for the LED lighting system, the data acquisition encoding board (1-7) and the main control unit (1-8); The data acquisition coding board (1-7) also has a video coding function, which encodes the video data collected by the high-definition camera (1-1) and outputs it through a network cable, forming an underground visual system.

3. The downhole visual electric control guidance device according to claim 1, characterized in that: The exterior of the deflection short section (2) comprises a spherical shell 1 (2-1), a spherical shell 2 (2-7) and a motor shell (2-9) which are connected in sequence; The spherical shell (2-1) and the motor shell (2-9) are connected by threads. The motor shell (2-9) has a motor (2-10) inside. The motor (2-10) is installed on the motor bracket (2-11). The motor encoder (2-12) is installed on the motor bracket (2-11). The output shaft of the motor (2-10) is connected to one end of the universal joint (2-8). The other end of the universal joint (2-8) is connected to the transmission shaft (2-4). The transmission shaft (2-4) is equipped with a key (2-3). The key (2-3) is connected to the spherical shell (2-1). When the control short section (5) issues an instruction to control the rotation of the motor, the transmission shaft (2-4) drives the spherical shell (2-1) to rotate, and the front end of the deflection short section (2) is connected to the imaging short section (1).

4. The downhole visual electric control guidance device according to claim 1, characterized in that: The rotating short section (3) has a second motor housing (3-11) on the outside, the second motor housing (3-11) is connected to the bearing seat (3-10) through a thread, the second motor housing (3-11) has a motor (3-9) inside, the output shaft of the motor (3-9) is connected to one end of the rotating shaft (3-5), the other end of the rotating shaft (3-5) is connected to the rotating body (3-2), and is locked using a locking nut (3-1), the rotating shaft (3-5) is installed with a deep groove ball (3-8) and a deep groove ball (3-12), and the rotating shaft (3-5) is installed with a thrust ball bearing (3-6) and a thrust ball bearing (3-7) The motor housing (3-11) has a circuit skeleton (3-13) inside, and a high-precision IMU phase sensor (3-14) and a motor encoder (3-15) are installed on the circuit skeleton (3-13). The high-precision IMU phase sensor (3-14) is used to accurately measure the attitude, position and motion state of the instrument. The motor encoder (3-15) is used to control the rotation angle of the motor. When the control short section (5) receives an instruction from the ground, the control motor (3-9) rotates, thereby rotating the rotating shaft (3-5) and the rotating body (3-2), driving the deflection short section (2) and the front imaging short section (1) to rotate.

5. The downhole visual electric control guidance device according to claim 1, characterized in that: The flexible short section (4) comprises a flexible body (4-1), an upper joint (4-2) and a lower joint (4-3); one end of the flexible body (4-1) is connected to the upper joint (4-2) via a thread, and the other end of the flexible body (4-1) is connected to the lower joint (4-3) via a thread; gaps are provided between the flexible sections (4-1-1) on the flexible body, and the flexible body (4-1) can adjust its bending angle.

6. A guidance method for a downhole visual electric-controlled guidance device according to any one of claims 1 to 5, characterized in that: The following steps are involved: The rotating sub (3) is internally integrated with a motor encoder (3-15) and a high-precision IMU phase sensor (3-14), and the deflecting sub (2) is internally integrated with a motor encoder (2-12). The imaging sub (1) visual system and the ground horizontal line are used for attitude compensation and superposition, thereby guiding the tool string into the target wellbore. The specific steps are as follows: Step 1: Before going down the well, the instrument string completes the attitude calibration: After the deflection sub (2) is returned to its position, the instrument string is in an axially straight state, and the instrument string completes attitude calibration before going down the well: a high-precision IMU phase sensor (3-14) is installed on the fixed frame inside the rotating sub (3). After the deflection sub (2) is returned to its position and the overall connection is completed, attitude compensation is performed with the ground horizontal line through the imaging sub (1) visual system; the calibration benchmark is based on the positive direction of the video image observed by the naked eye, and the roll angle compensation value Ang0 (relative to the horizontal plane) is recorded at this time, and the gravity direction is defined as 0°, and the clockwise angle increases, 360° coincides with 0°, and 180° is directly above; all subsequent downhole video images are processed through the instrument's internal visual system and real-time roll angle compensation to ensure that the image content accurately corresponds to the earth's gravity coordinate system; Step 2: Lower the instrument to the branch wellbore: When the tool string is lowered to the imaging sub and the target branch wellbore is observed, it is slowly advanced until the front end of the tool string is flush with the upper edge of the target branch wellhead; Step 3: Obtain branch well images and overlay them: The branch well image PicX is acquired through the downhole vision system, and the real-time roll angle data rollX is acquired through the high-precision IMU phase sensor. The video image information is uploaded to the surface host computer software. After compensating for the PicX-superimposed rollX angle, the surface software calculates the actual angle AngX of the branch wellhead relative to the gravity direction based on image feature analysis. This controls the rotation of the rotating sub to the corresponding angle, aligning the sloped surface with the branch wellbore. Step 4: Rotate the deflection sub (2) and guide it into the branch well: From step 3, it can be seen that the bevel surface rotates to the branch well position, and the motor (2-10) in the bevel sub drives the spherical shell 1 (2-1) to rotate relative to the spherical shell 2 (2-7) through the coupling (2-8). The bevel angle α is used to make the deflection angle β cover the range of 0–2α, so that the axis of the bevel surface is aligned with the branch well head. Finally, according to the geometric relationship between the length L of the imaging sub (1) and the deflection angle, D = L × tan (2α), the end rotation diameter trajectory is generated; Step 5: Instrument adjustment after entering the branch well: After the rotating short section (3) drives the deflection direction to align with the target branch wellhead, the deflection short section (2) fine-tunes the angle in conjunction with the real-time video to guide the front end of the instrument to slide into the target branch wellbore. At the same time, the flexible short section (4) dynamically compensates for the change in wellbore curvature through the unicorn structure. After the deflection short section (2) is fully entered, the short section gradually rotates back to its original position, and finally the entire instrument string enters the target branch wellbore.

7. A downhole visual electric-controlled guidance method according to claim 6, characterized in that: The calculation formula in step 3 is as follows: AngX=Picx-rollX; When rollX=30°, the current branch well image information PicX temporarily assumes the gravity direction is 0°, and the downhole vision system and the horizontal plane are at an angle of 270°. The real-time roll angle data rollX(30°) is obtained based on the high-precision IMU phase sensor, and the actual angle of the branch well in the image PicX is calculated to be 240°, that is, 270°-30°. At this time, the rotating short section is controlled to rotate 60° clockwise, 240°-180°. Here, the inclined surface is a cross surface, and rotating 60° is the same as rotating 240°. Specifically, the motor (3-9) drives the rotating shaft (3-4), driving the deflecting short section and the imaging short section to rotate as a whole.

8. The downhole visual electric control guidance method according to claim 6, characterized in that: In the step 4, the deflection angle covers the range of 0–2α; When the spherical shell 1 (2-1) and the spherical shell 2 (2-7) are in a straight line, the deflection angle β = α-α, that is, 0°; When the spherical shell 1 (2-1) and the spherical shell 2 (2-7) are at the maximum angle, the deflection angle is β=α+α, that is, 2α.

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