A horizontal well wall perforating tool

Abstract

The application discloses a horizontal well pipe wall perforating tool, which comprises a differential gear differential crawling short section, an anchoring centering short section, a rotary connecting short section and an eccentric perforating short section. The differential gear differential crawling short section realizes differential walking and variable diameter folding functions through a first gear shifting driving mechanism. The anchoring centering short section adopts a telescopic multi-stage anchoring arm structure to ensure that the tool is stably centered and bears axial counterforce during perforation. The rotary connecting short section enables the modules to keep synchronous rotation in the circumferential direction. The eccentric perforating short section integrates a second gear shifting driving mechanism, a lower eccentric structure and a hydraulic perforating executing mechanism to realize radial extension of a drill bit, rotary cutting and control of a perforating position. The application adopts module cooperative matching to complete multi-section perforating tasks through differential propulsion, directional anchoring, eccentric control and hydraulic perforation and the like, and has the functions of jamming obstacle surmounting, self-adaptive posture adjustment and retraction protection. The application has the advantages of compact structure, flexible control and high perforating precision and is suitable for all-directional perforating operation of a horizontal well section pipe wall.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, specifically to a horizontal well casing perforation tool suitable for perforation operations in the horizontal well drilling section and horizontal section casing string. Background Technology

[0002] In the exploration and development of oil and gas, the widespread application of horizontal well technology has improved the efficiency of oil and gas resource extraction. In horizontal well development, especially in pressurized conditions such as wellbore maintenance and tubing string jamming, perforation is often required to release wellbore pressure to facilitate subsequent cutting and tubing pull-out operations. However, in horizontal wells, due to the long well sections and complex build-up sections, which are typically accompanied by large inclination angles and small radii of curvature, perforation tools are prone to jamming, increased friction, and difficulty in reaching the target location. Therefore, higher demands are placed on the adaptability and deployment performance of perforation tools.

[0003] Existing conventional drilling tools are mainly cable-driven drilling tools or pyrotechnic drilling devices. These tools are mostly suitable for vertical well sections or well sections with small inclination. Existing cable-driven drilling tools lack adaptability to complex well sections, and have problems such as poor passage in the build-up section, inaccurate positioning, and easy jamming. In addition, pyrotechnic drilling is limited by the transportation, storage, and safety control of pyrotechnic materials, which restricts its application in field emergency situations.

[0004] In summary, there is an urgent need to design a downhole pipe wall perforation tool and method suitable for complex build-up sections of horizontal wells, possessing good crawling and directional control capabilities. Summary of the Invention

[0005] This invention provides a horizontal well casing perforation tool and method with precise operation and strong adaptability, in order to solve the technical problems of existing technologies that cannot adapt to the complex working conditions of the horizontal well build-up section and horizontal section, and that there are problems such as jamming and inaccurate positioning, so as to achieve the purpose of stable lowering and precise positioning of the perforation tool in the horizontal well.

[0006] Therefore, the technical solution of the present invention is as follows:

[0007] A horizontal well casing perforation tool includes a shift differential creeping sub, an anchoring centering sub, a rotary connection sub, and an eccentric perforation sub;

[0008] The shift differential crawling section is used to drive the drilling tool along the pipe wall in the inclined and horizontal sections.

[0009] The anchoring centering short section is used to position, center, and anchor the drilling tool when it encounters resistance in the sloping section or during drilling operations.

[0010] The rotating connecting section is used to achieve a relative rotating connection between the anchoring centering section and the eccentric perforated section.

[0011] The eccentric perforated short section is used to achieve eccentricity of the perforated short section and to drill holes in the pipe wall while maintaining overall centering.

[0012] In this application, the drilling tool is lowered into the well via a cable. A differential speed crawling sub allows the tool to actively crawl and overcome obstacles in the vertical, directional, and horizontal sections. When encountering obstacles or needing attitude adjustment, an anchoring and centering sub is used to anchor and center the tool in place, and the differential speed crawling sub further adjusts the circumferential attitude of the crawling wheels to ensure smooth passage through complex well sections. After the tool reaches the predetermined drilling position, the anchoring and centering sub again provides stable anchoring and precise centering. Then, an eccentric drilling sub is used to achieve overall rotational positioning of the drilling assembly and eccentricity of the drilling sub, ultimately completing the drilling operation. After the drilling operation is completed, all subs are closed, and the tool is retrieved via cable, completing the drilling operation.

[0013] In this design, the shifting differential creeping section and the anchoring centering section work together to provide a rigid support base for the drilling tool when it encounters obstruction or needs to rotate to adjust its posture. This prevents displacement or eccentricity from affecting operational accuracy, making it particularly suitable for precise operations in the directional drilling and perforation sections. The rotary connecting section, as the core of the rotary connection between sections, has a compact structure and smooth rotation, ensuring efficient and stable relative rotation between adjacent sections and providing the necessary mechanism for circumferential positioning of the drill bit. The eccentric perforation section integrates an eccentric rotation mechanism, a perforating drill bit, and a hydraulic control system, enabling four functions: rotational positioning of the perforation assembly, eccentricity, drill bit rotation, and hydraulic telescopic control. It is suitable for various pipe wall structures.

[0014] Furthermore, the differential speed crawling sub includes a first shifting drive mechanism that drives the crawling wheels to rotate axially and realizes the circumferential rotation of the differential speed crawling sub, a differential mechanism that enables the crawling wheels to rotate at different speeds in the downhole directional drilling section, and a first diameter-changing mechanism that drives all the crawling wheels to extend or retract radially.

[0015] In this design, the first shifting mechanism drives the crawler wheels to roll axially, enabling stable advancement of the entire tool series within the wellbore. In complex situations such as encountering obstruction or failing to overcome obstacles, this drive mechanism switches to a circumferential drive mode. In conjunction with the anchoring center section, the short section first anchors and positions itself, then the differential speed crawler section slowly rotates around the tool axis, adjusting the crawler wheel's path. The differential mechanism allows the two crawler wheels to rotate at different speeds during crawling, adapting to curved or asymmetrical wellbore structures and improving wall adhesion and forward stability. The first diameter-changing mechanism controls the crawler wheels to extend or retract radially, enabling flexible contact or disengagement between the perforating tool and the wellbore wall.

[0016] Furthermore, the first shift drive mechanism includes a first drive device for driving a first transmission shaft. The first transmission shaft is fixedly connected to a first synchronous pulley and is rotatably but non-drivenly connected to a first spur gear and a second spur gear, respectively. The first synchronous cover rotates synchronously under the drive of the first synchronous pulley. A first lever can drive the first synchronous cover to slide axially along the first synchronous pulley. A first linear drive device drives the first lever to move circumferentially in a linear motion to control the engagement of the first spur gear and the second spur gear. The first spur gear drives the first bevel gear to rotate through a first intermediate transmission assembly. The first bevel gear transmits power to the differential mechanism. The second spur gear drives the first internal gear to rotate through a second intermediate transmission assembly. The first internal gear is fixedly connected to a first crawling housing and rotatably connected to a second crawling housing.

[0017] In this design, the connection method between the synchronizing cover and the synchronizing pulley is not limited; it can be achieved using a sliding key, spline, or other similar connection. The first linear drive unit preferably employs a high-precision linear drive to ensure smooth execution of gear shifting actions under complex well conditions, thereby effectively improving the stability and reliability of the gear shifting mechanism.

[0018] In addition, the first intermediate transmission assembly and the second intermediate transmission assembly can achieve torque or speed adjustment through multi-stage transmission according to actual working conditions, thereby improving the power adaptability of the drilling tool in downhole operations.

[0019] Furthermore, the differential mechanism includes a second bevel gear meshing with the first bevel gear, the second bevel gear being fixedly connected to the third bevel gear, the third bevel gear transmitting power to the fifth bevel gear through at least two sets of fourth bevel gears, the third bevel gear and the fifth bevel gear being fixedly connected to the second drive shaft and the third drive shaft respectively, and driving the crawler wheel to rotate through the third intermediate transmission assembly.

[0020] In this design, when the crawling wheels on both sides crawl synchronously at the same speed, the multiple sets of fourth bevel gears in the differential mechanism remain stationary, allowing power to be directly and stably transmitted to the crawling wheels on both sides for stable propulsion. However, when the drilling tool needs to adjust its attitude or perform obstacle-crossing maneuvers in the directional drilling section or under complex pipe wall conditions, the crawling wheels on both sides rotate at different speeds. At this time, the multiple sets of fourth bevel gears will rotate to automatically offset the speed difference, improving the tool's ability to adapt to the downhole environment.

[0021] In addition, to meet the crawling torque requirements in the high resistance environment of the downhole obstacle crossing or large-angle skewing section, the third intermediate transmission component connected to the output end of the differential mechanism adopts a multi-stage gear system design, which realizes torque amplification and output stability through the combination of gear stages.

[0022] Furthermore, the first diameter-changing mechanism includes a second driving device, which is fixedly connected to a first push rod. The first push rod is fixedly connected to a central support through a first elastic device. The central support and the fixed support are rotatably connected to the suspension arm, and the fixed support is fixedly connected to the crawling arm.

[0023] In this design, the suspension arm is equipped with a flexible suspension structure, which enables the crawling wheels to have a certain radial adaptive adjustment capability during forward movement, ensuring that the crawling wheels always maintain good contact with the pipe wall and improving obstacle crossing ability.

[0024] Furthermore, the anchoring center section includes a third driving device, which is fixedly connected to a second push rod. The second push rod is fixedly connected to an upper anchoring bracket via a second elastic device. The upper anchoring bracket is fixedly connected to an upper slider, which is rotatably connected to an upper anchoring arm. The upper anchoring arm is rotatably connected to a lower anchoring arm, which is rotatably connected to a lower slider. The lower slider is fixedly connected to a lower anchoring bracket. The second elastic device and the upper anchoring bracket are slidably connected to a central axis and can slide along the central axis axially.

[0025] In this design, the anchoring arm is radially extended via a slider driven by a third drive unit, achieving rapid centering and stable anchoring downhole. Working in conjunction with the differential shifting crawling sub and the eccentric perforating sub, it improves obstacle-crossing efficiency and perforation accuracy, adapting to complex well conditions.

[0026] In addition, a limit mechanism can be installed between the upper and lower anchoring arms to limit their maximum extension angle and prevent damage to the mechanism caused by excessive extension.

[0027] Furthermore, the rotary connecting section includes a rotary housing, which is fixedly connected to a first rotary bearing, a second rotary bearing, and a split threaded ring.

[0028] Furthermore, the eccentric perforated section includes a perforation mechanism for perforating the pipe wall, a second shifting drive mechanism for driving the perforation mechanism to be eccentric and the eccentric perforated section to rotate as a whole, and a lower eccentric mechanism for maintaining the force balance during perforation.

[0029] The second shift drive mechanism has the same structure as the first shift drive mechanism, including a fourth drive device, a fourth transmission shaft, a second synchronous pulley, a second synchronous cover, a second lever, a second linear drive device, and the fourth transmission shaft is rotatably but non-drivenly connected to the third spur gear and the fourth spur gear respectively. The second synchronous cover rotates synchronously under the drive of the second synchronous pulley and slides along the axial direction of the second synchronous pulley under the action of the second lever to control the engagement of the third spur gear and the fourth spur gear. The third spur gear is poweredly engaged with the fifth spur gear through the fourth intermediate transmission assembly. The fifth spur gear is fixedly connected to the anchoring center short section. The fourth spur gear is poweredly transmitted to the first perforated housing through the fifth intermediate transmission assembly.

[0030] The lower eccentric mechanism includes a fifth driving device that drives a sixth spur gear to rotate. The sixth spur gear transmits power to the first perforated housing through a sixth intermediate transmission assembly.

[0031] In this design, the eccentric perforation section, via a second shifting drive mechanism and a lower eccentric mechanism, is used to achieve positioning and eccentric movement of the perforation section. When the perforation tool reaches the predetermined position, the second shifting drive mechanism first switches to the rotary gear, causing the perforation section to rotate slowly, thereby achieving precise positioning in the perforation direction. After positioning, the shifting drive mechanism switches to the eccentric gear, cooperating synchronously with the lower eccentric mechanism to achieve radial eccentric movement of the perforation mechanism. The eccentric structure is symmetrically arranged, enabling balanced force distribution during perforation operations, significantly improving the stability and reliability of the perforation process, avoiding section swaying or structural damage caused by off-center loading, and ensuring perforation accuracy and operational safety.

[0032] Furthermore, the fourth and fifth intermediate transmission components can employ multi-stage transmission to achieve torque or speed adjustment according to actual working conditions. The second linear drive unit preferably uses a high-precision linear drive to ensure smooth gear shifting under complex well conditions.

[0033] Furthermore, the piercing mechanism includes a hydraulic telescopic control device for controlling the extension and retraction of the drill bit and a drill bit rotation control mechanism for rotating the drill bit. The piercing rotation control mechanism includes a sixth drive device that drives a sixth bevel gear to rotate. The sixth bevel gear is in dynamic mesh with a seventh bevel gear. The seventh bevel gear is fixedly connected to a rotating seat. The rotating seat is fixedly connected to the drill bit through an internal spline, and a third elastic device is provided between the two. The rotating seat is rotatably connected to a fixed cover through a third rotating bearing. The fixed cover is fixedly connected to the first piercing outer shell.

[0034] Furthermore, the hydraulic telescopic control device includes an oil tank, a hydraulic pump, a check valve, a two-position three-way directional valve, a pressure reducing valve, an accumulator, and a pilot-operated relief valve. The hydraulic pump is connected to the oil tank via an oil line to provide the system pressure oil source. The hydraulic pump is also connected to the two-position three-way directional valve via another oil line to form the drill bit extension oil path. The two-position three-way directional valve has two switching states, used to control the hydraulic oil entering the drill bit extension cavity and the hydraulic oil in the extension cavity flowing back to the oil tank through the two-position three-way directional valve. The hydraulic pump is connected to the check valve, the pressure reducing valve, the accumulator, and the pilot-operated relief valve sequentially via another oil line to form the drill bit retraction oil path. The drill bit retraction oil path is connected to the drill bit retraction cavity via a rotary sealing ring. The rotary sealing ring is rotatably connected to the rotary seat.

[0035] In this design, a hydraulic telescopic control device is used to drive the extension and retraction of the drill bit. The system's drill bit extension chamber is designed to operate at a pressure of 10 MPa, while the drill bit retraction chamber is pressure-limited to 5 MPa via a pressure-reducing valve. Under normal circumstances, the drill bit is held in its initial retracted state by a third elastic device. When the hydraulic pump starts, hydraulic oil enters the drill bit extension chamber via a two-position three-way directional valve, pushing the drill bit outward. Simultaneously, oil enters the retraction chamber, maintaining a pressure of only 5 MPa due to the pressure-reducing valve, creating a pressure difference that drives the drill bit to extend stably. After drilling is completed, the hydraulic pump shuts off, and the directional valve switches to connect the extension chamber to the oil tank. The retraction chamber releases pre-stored energy (at a pressure of 5 MPa) through an accumulator. Combined with the third elastic device, this achieves automatic drill bit retraction. This structure can retract the drill bit without relying on hydraulic pump pressure, ensuring smooth drill bit retraction even in the event of system failure, significantly improving operational safety and system reliability.

[0036] In addition, the retraction oil circuit is equipped with a pilot-operated relief valve to prevent overpressure in the hydraulic system during drill bit extension, providing pressure relief protection. The energy storage method of the accumulator is not limited and can be flexibly configured according to site conditions and structure. The working pressure of the drill bit extension oil chamber can be flexibly set according to site requirements, but it must always be ensured to be higher than the retraction circuit pressure to guarantee effective drill bit extension and control accuracy.

[0037] The specific layout of hydraulic components such as hydraulic pumps and check valves in the hydraulic telescopic device can be adjusted according to the downhole space layout and actual working conditions, as long as the hydraulic circuit function required by this solution can be achieved.

[0038] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0039] 1. A horizontal well casing wall perforation tool of the present invention achieves adaptive forward movement and obstacle crossing capability in complex downhole sections through a shift differential crawling sub. The crawling sub can flexibly select axial crawling or switch to circumferential differential rotation mode through the first shift drive mechanism to adapt to irregular well walls or obstruction situations.

[0040] 2. The present invention provides a horizontal well casing perforation tool, which achieves precise centering and stable positioning of the tool during downhole attitude adjustment and perforation process by anchoring a centering short section. The anchoring device is symmetrically arranged and can be automatically reset with the elastic buffer structure, improving operational safety. It can be linked with the crawling short section to adjust the attitude and reposition in the directional or horizontal section, ensuring accurate tool movement direction and balanced force.

[0041] 3. The horizontal well casing perforation tool of the present invention achieves angular coordination and relative rotation between the internal short sections of the perforation tool through rotating connecting short sections, which is particularly suitable for eccentric perforation positioning, improving overall maneuverability and downhole operation accuracy.

[0042] 4. The present invention provides a horizontal well casing perforation tool that achieves precise eccentric and directional perforation of the perforation section while maintaining overall centering through an eccentric perforation sub. The perforation section first undergoes rotational positioning and then eccentric action through a second shift drive mechanism and a lower eccentric mechanism, with the two-step positioning improving perforation accuracy. The eccentric structure adopts a symmetrical arrangement on both sides, resulting in more balanced force distribution and ensuring the stability of the perforation process and the life of the drill bit.

[0043] 5. The horizontal well casing perforation tool of the present invention achieves safe and controllable management of the drill bit extension and retraction process through a hydraulic drill bit extension and retraction control system. The hydraulic pump drives the drill bit extension and retraction in conjunction with a two-position three-way directional valve. An accumulator is provided in the retraction circuit, so that even if the hydraulic pump fails, the drill bit can be automatically retrieved under the action of the third elastic component and the accumulator mechanism to avoid the risk of jamming. The system is equipped with a pilot-operated relief valve to provide overpressure protection for the oil circuit during the drill bit extension process, thereby improving the overall reliability and safety of the system. Attached Figure Description

[0044] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0045] Figure 1 This is a front view of a specific embodiment of the present invention;

[0046] Figure 2 This is a schematic diagram of the differential crawling section in a specific embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the internal structure of the differential crawling section in a specific embodiment of the present invention;

[0048] Figure 4 for Figure 3 View from direction A;

[0049] Figure 5 for Figure 3 BB section view;

[0050] Figure 6 This is a schematic diagram of the structure of the anchoring centering short section in a specific embodiment of the present invention;

[0051] Figure 7 This is a schematic diagram of the internal structure of the anchoring center section in a specific embodiment of the present invention;

[0052] Figure 8 This is a schematic diagram of the structure of the rotary connecting short section in a specific embodiment of the present invention;

[0053] Figure 9 for Figure 8 CC section view;

[0054] Figure 10 This is a schematic diagram of the eccentric perforated short section in a specific embodiment of the present invention;

[0055] Figure 11 for Figure 10 DD section view;

[0056] Figure 12 for Figure 10 Remove the lower left isometric view of the outer shell at point G;

[0057] Figure 13 for Figure 10 The isometric view of point I with the outer shell removed;

[0058] Figure 14 for Figure 1 A magnified view of section J with the outer shell removed;

[0059] Figure 15 for Figure 10 A schematic diagram of the structure at point H;

[0060] Figure 16 for Figure 15 EE section view;

[0061] Figure 17 for Figure 15 The F-direction view.

[0062] Figure 18 Hydraulic schematic diagram of hydraulic telescopic control device

[0063] The attached diagram shows the markings and corresponding component names:

[0064] 1- Shift differential creeper section, 101- First drive unit, 102- First drive shaft, 103- First synchronizer pulley, 104- First spur gear, 105- Second spur gear, 106- First synchronizer cover, 107- First lever, 108- First linear drive unit, 109- First intermediate transmission assembly, 110- First bevel gear, 111- Second intermediate transmission assembly, 112- First internal gear, 113- First creeper housing, 114- Second creeper... 115-Second bevel gear, 116-Third bevel gear, 117-Fourth bevel gear, 118-Fifth bevel gear, 119-Second drive shaft, 120-Third drive shaft, 121-Third intermediate transmission assembly, 122-Crawling wheel, 123-Second drive unit, 124-First push rod, 125-First elastic device, 126-Center support, 127-Suspension arm, 128-Fixed support, 129-Crawling arm, 2-Anchoring center short section. 201-Third drive unit, 202-Second push rod, 203-Second elastic device, 204-Upper anchoring bracket, 205-Upper slider, 206-Upper anchoring arm, 207-Lower anchoring arm, 208-Lower slider, 209-Lower anchoring bracket, 210-Central shaft, 3-Rotary connecting section, 301-Rotary housing, 302-First rotary bearing, 303-Second rotary bearing, 304-Split threaded ring, 4-Eccentric perforated section, 401-Fourth drive unit, 402-Fourth transmission shaft, 403-Second synchronous pulley, 404-Second synchronous cover, 405-Second lever, 406-Second linear drive unit, 407-Third spur gear, 408-Fourth linear drive unit Gear, 409-Fourth intermediate transmission assembly, 410-Fifth spur gear, 411-Fifth intermediate transmission assembly, 412-First perforated housing, 413-Fifth drive unit, 414-Sixth spur gear, 415-Sixth intermediate transmission assembly, 416-Drill bit, 417-Sixth drive unit, 418-Sixth bevel gear, 419-Seventh bevel gear, 420-Rotating seat, 421-Third elastic device, 422-Third rotating bearing, 423-Fixed cover, 424-Oil tank, 425-Hydraulic pump, 426-One-way valve, 427-Two-position three-way directional valve, 428-Pressure reducing valve, 429-Accumulator, 430-Pilot-operated relief valve, 431-Rotary sealing ring. Detailed Implementation

[0065] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention. Example 1

[0066] A horizontal well casing wall perforation tool, the tool components are as follows Figure 1As shown, the perforation tool includes a shift differential crawling section 1, an anchoring centering section 2, a swivel connecting section 3, and an eccentric perforation section 4;

[0067] The shift differential crawling section 1 is used to drive the drilling tool to move along the pipe wall in the inclined section and the horizontal section.

[0068] The anchoring centering short section 2 is used to position, center and anchor the drilling tool when it encounters obstruction in the inclined section or during drilling operations.

[0069] The rotating connecting section 3 is used to realize the relative rotating connection between the anchoring centering section 2 and the eccentric perforated section 4;

[0070] The eccentric perforated short section 4 is used to achieve eccentricity of the perforated short section and to drill holes in the pipe wall while maintaining overall centering.

[0071] In this example, the components are, in order: differential creeping section 1, anchoring centering section 2, swivel connection section 3, eccentric perforated section 4, swivel connection section 3, anchoring centering section 2, and differential creeping section 1. The differential creeping section and the anchoring centering section are fixedly connected by their split threads. Example 2

[0072] A horizontal well casing perforation tool, based on Embodiment 1, wherein the shift differential creeping sub 1 is as follows: Figure 2 and Figure 3 As shown, it includes a first shift drive mechanism that drives the crawler wheel 122 to rotate in the axial direction and realizes the differential crawler sub 1 to rotate circumferentially around the tool axis, a differential mechanism for realizing the differential rotation of the left and right crawler wheels 122 in complex well sections such as downhole directional drilling sections, and a first variable diameter mechanism for controlling the retraction and extension of the crawler wheel 122 in the radial direction.

[0073] In this example, the first shift drive mechanism is as follows: Figure 5As shown, the system includes a first drive device 101 motor, which drives a first transmission shaft 102. The first transmission shaft 102 is fixedly connected to a first synchronous pulley 103 and is rotatably but non-drivenly connected to a first spur gear 104 and a second spur gear 105 respectively. A first synchronous cover 106 rotates synchronously under the drive of the first synchronous pulley 103. A first lever 107 can drive the first synchronous cover 106 to slide axially along the first synchronous pulley 103. A first linear drive device 108 drives the first lever 107 to move linearly in the circumferential direction to control the engagement of the first spur gear 104 and the second spur gear 105. The first spur gear 104 drives a first bevel gear 110 to rotate through a first intermediate transmission assembly 109. The first bevel gear 110 transmits power to the differential mechanism. The second spur gear 105 drives a first internal gear 112 to rotate through a second intermediate transmission assembly 111. The first internal gear 112 is fixedly connected to a first crawling shell 113 and rotatably connected to a second crawling shell 114.

[0074] In this embodiment, the differential mechanism is as follows: Figure 3 As shown, it includes a second bevel gear 115 that meshes with the first bevel gear 110. The second bevel gear 115 is fixedly connected to the third bevel gear 116. The third bevel gear 116 transmits power to the fifth bevel gear 118 through at least two sets of fourth bevel gears 117. Multiple sets of fourth bevel gears 117 can be provided to make the power transmission more stable. The third bevel gear 116 and the fifth bevel gear 118 are fixedly connected to the second drive shaft 119 and the third drive shaft 120, respectively, and rotate through the third intermediate transmission assembly 121 and the final crawling wheel 122.

[0075] In this embodiment, the first diameter changing mechanism is as follows: Figure 4 As shown, a hydraulic cylinder with a second drive device 123 is used to control the radial extension or retraction of the crawling wheel 122 to achieve contact or retraction with the well wall. The second drive device 123 is fixedly connected to a first push rod 124, and the first push rod 124 is fixedly connected to a central support 126 through a first elastic device 125 to maintain an initial elastic connection. The central support 126 and the fixed support 128 are hinged to the suspension arm 127. The crawling arm 129 extends or retracts in conjunction with the suspension arm 127, thereby realizing the automatic diameter change function of the entire crawling mechanism.

[0076] Preferably, the suspension arm 127 adopts an elastic suspension structure, which can adaptively adjust its inner diameter when encountering sudden changes in the well wall or local obstacles, thereby improving its obstacle-crossing ability. Example 3

[0077] A horizontal well casing perforation tool, based on embodiment 1 or 2, wherein the anchoring centering short section 2 is as follows: Figure 6 and Figure 7 As shown, the device includes a third driving device 201 hydraulic cylinder, which is fixedly connected to a second push rod 202 to provide a power source for the anchoring device. The second push rod 202 is connected to an upper anchoring bracket 204 through a second elastic device 203 to form an elastic buffer structure, which is beneficial for force buffering and return during the anchoring process. The upper anchoring bracket 204 is fixedly connected to an upper slider 205, which is rotatably connected to an upper anchoring arm 206. The upper anchoring arm 206 is rotatably connected to a lower anchoring arm 207, which is rotatably connected to a lower slider 208. The lower slider 208 is fixedly connected to a lower anchoring bracket 209 to form a linkage structure to realize the expansion and contraction of the anchoring arm. The second elastic device 203 and the upper anchoring bracket 204 are slidably connected to a central shaft 210 and can slide along the axial direction of the central shaft 210. Example 4

[0078] A horizontal well casing perforation tool, based on any of the above embodiments, wherein the rotary connecting section is as follows: Figure 8 and Figure 9 As shown, it includes a rotating housing 301, which is fixedly connected to a first rotating bearing 302, a second rotating bearing 303 and a split threaded ring 304.

[0079] In this embodiment, the rotary connecting section is used to achieve relative rotational positioning of the tool as a whole while maintaining axial stability, facilitating the adjustment of the piercing angle and multi-angle operation. To achieve reliable connection and detachable structure between modules, the rotary housing 301 is also fixedly connected to the split threaded ring 304, ensuring both high-strength connection of the rotary connecting part and facilitating subsequent modular maintenance, replacement, and assembly operations.

[0080] Preferably, to enhance the ability to withstand complex downhole working conditions, a sealing ring structure can be provided at the mating point between the rotating housing 301 and the bearing to prevent foreign objects such as mud and well fluid from entering the bearing and to ensure the reliability of long-term rotational operation. Example 5

[0081] A horizontal well casing perforation tool, based on any of the above embodiments, wherein the eccentric perforation sub 4 is as follows: Figures 10 to 18 As shown, it includes a perforation mechanism for realizing pipe wall perforation, a second shift drive mechanism for driving the perforation mechanism to be eccentric and the eccentric perforation section 4 to rotate as a whole, and a lower eccentric mechanism for maintaining the force balance of perforation.

[0082] In this embodiment, the structure of the second shift drive mechanism is the same as that of the first shift drive mechanism, including a fourth drive device 401 motor, a fourth transmission shaft 402, a second synchronous pulley 403, a second synchronous cover 404, a second lever 405, a second linear drive device 406, and the fourth transmission shaft 402 is rotatably but non-drivenly connected to the third spur gear 407 and the fourth spur gear 408 respectively. The second synchronous cover 404 rotates synchronously under the drive of the second synchronous pulley 403 and slides axially along the second synchronous pulley 403 under the action of the second lever 405 to control the engagement of the third spur gear 407 and the fourth spur gear 408. The third spur gear 407 is poweredly engaged with the fifth spur gear 410 through the fourth intermediate transmission assembly 409. The fifth spur gear 410 is fixedly connected to the anchoring centering short section 2. The fourth spur gear 408 transmits power to the first perforated housing 412 through the fifth intermediate transmission assembly 411.

[0083] In this embodiment, the lower eccentric mechanism includes a fifth drive device 413 motor, which drives a sixth spur gear 414 to rotate. The sixth spur gear 414 transmits power to the first perforated housing 412 through a sixth intermediate transmission assembly 415.

[0084] In this embodiment, the piercing mechanism includes a hydraulic telescopic control device for controlling the extension and retraction of the drill bit 416 and a drill bit rotation control mechanism for rotating the drill bit. The piercing rotation control mechanism includes a sixth drive device 417 motor that drives a sixth bevel gear 418 to rotate. The sixth bevel gear 418 is in dynamic mesh with a seventh bevel gear 419. The seventh bevel gear 419 is fixedly connected to a rotating seat 420. The rotating seat 420 is fixedly connected to the drill bit 416 via an internal spline, and a third elastic device 421 is provided between the two. The rotating seat 420 is rotatably connected to a fixed cover 423 via a third rotating bearing 422. The fixed cover 423 is fixedly connected to the first piercing outer shell 412.

[0085] In this embodiment, the hydraulic telescopic control device includes an oil tank 424, a hydraulic pump 425, a check valve 426, a two-position three-way directional valve 427, a pressure reducing valve 428, an accumulator 429, and a pilot-operated relief valve 430. The hydraulic pump 425 is connected to the oil tank 424 via an oil pipeline to provide the system pressure oil source. The hydraulic pump 425 is connected to the two-position three-way directional valve 427 via an oil pipeline to form the drill bit extension oil path. The two-position three-way directional valve 427 has... There are two switching states, used to control the hydraulic oil entering the extension cavity of the drill bit 416 and the hydraulic oil in the extension cavity flowing back to the oil tank through the two-position three-way directional valve 427. The hydraulic pump 425 is connected in sequence to the check valve 426, the pressure reducing valve 428, the accumulator 429, and the pilot-operated relief valve 430 through other oil lines, forming a drill bit retraction oil circuit. The drill bit retraction oil circuit is connected to the retraction cavity of the drill bit 416 through a rotary sealing ring 431. The rotary sealing ring 431 is rotatably connected to the rotary seat 420. Example 6

[0086] A horizontal well casing wall perforation tool, based on any of the above embodiments, the specific steps of horizontal well perforation operation are as follows:

[0087] S1: Connect all the short sections of the drilling tool on the ground and lower it into the well via cable. In the vertical section, it can be lowered according to the weight of the drilling itself or the shift differential short section 1 can be activated to assist in crawling.

[0088] S2: After entering the downhole directional section or horizontal section, start the shift differential short section 1 to drive the crawling wheels forward;

[0089] S3: When encountering an obstacle during crawling, activate the anchoring centering section 2 for temporary anchoring. Shift the differential crawling section 1 to the circumferential rotation gear, adjust the crawling wheel's attitude and orientation, and close the anchoring centering section 2 to continue crawling after overcoming the obstacle;

[0090] S4: Upon reaching the target perforation position, activate anchoring centering short section 2 for centering anchoring;

[0091] S5: Start the eccentric perforation section 4. First, drive the perforation mechanism to achieve circumferential rotation and complete the orientation of the perforation direction. Then, eccentrically deflect the perforation mechanism radially to start the perforation operation.

[0092] S6: After the perforation operation is completed, start all short section retraction devices, lift the cable to retrieve it, and complete the perforation operation.

[0093] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish different entities or operations, and do not necessarily require or imply any actual relationship or order between these entities or operations. Furthermore, the term "connection" as used herein, unless otherwise specified, can refer to a direct connection or an indirect connection via other components.

Claims

1. A horizontal well wall perforating tool characterized by, The perforating tool comprises a shift differential crawling sub (1), an anchoring centering sub (2), a rotary connecting sub (3) and an eccentric perforating sub (4); The shift differential crawling sub (1) is used for driving the perforating tool to move along the pipe wall in the build-up section and the horizontal section, and comprises a first shift driving mechanism, which is used for driving the crawling wheel (122) of the shift differential crawling sub (1) to rotate in the axial direction and realizing the circumferential rotation of the shift differential crawling sub (1), and comprises a first driving device (101), which is used for driving a first transmission shaft (102) to rotate, the first transmission shaft (102) is fixedly connected with a first synchronous wheel (103), and is rotatably but non-drivably sleeved with a first spur gear (104) and a second spur gear (105), a first synchronous cover (106) is slidably connected with the first synchronous wheel (103) and rotates synchronously, the first synchronous cover (106) is connected with a first shifting rod (107), a first linear driving device (108) is connected with the first shifting rod (107) and is used for driving the first shifting rod (107) to move linearly in the axial direction, the first synchronous cover (106) slides in the axial direction along the first synchronous wheel (103) under the pushing of the first shifting rod (107), the first linear driving device (108) drives the first shifting rod (107) to move linearly to control the engagement of the first spur gear (104) and the second spur gear (105), the first spur gear (104) drives a first bevel gear (110) to rotate through a first intermediate transmission assembly (109), the first bevel gear (110) is power-transmitted with a differential mechanism of the shift differential crawling sub (1), the second spur gear (105) drives a first internal gear (112) to rotate through a second intermediate transmission assembly (111), the first internal gear (112) is arranged in the shift differential crawling sub (1) and is fixedly connected with a first crawling shell (113) of the shift differential crawling sub (1), and the first internal gear (112) is rotatably connected with a second crawling shell (114) of the shift differential crawling sub (1); The anchoring centering sub (2) is used for realizing the positioning, centering and anchoring of the perforating tool when the perforating tool meets resistance in the build-up section or during the perforating operation; The rotary connecting sub (3) is used for realizing the relative rotary connection between the anchoring centering sub (2) and the eccentric perforating sub (4); The eccentric perforating sub (4) comprises a perforating mechanism for realizing the perforation of the pipe wall, a second shift driving mechanism for driving the perforating mechanism to be eccentric and the whole eccentric perforating sub (4) to rotate, and a lower eccentric mechanism for keeping the perforation force balanced; The eccentric perforating sub (4) is used for realizing the eccentricity of the perforating mechanism and perforating the pipe wall on the basis of the whole centering.

2. A horizontal well wall perforating tool according to claim 1, characterized in that, The shift differential crawling short section (1) further comprises crawling wheels (122), a differential mechanism for driving the crawling wheels (122) to rotate at different rotating speeds in the downhole build-up section, and a first variable-diameter mechanism for driving all the crawling wheels (122) to expand or retract in the radial direction.

3. A horizontal well wall perforating tool as defined in claim 2, wherein, The differential mechanism comprises a second bevel gear (115) engaged with the first bevel gear (110), the second bevel gear (115) is fixedly connected with a third bevel gear (116), the third bevel gear (116) transmits power to a fifth bevel gear (118) through at least two groups of fourth bevel gears (117), the third bevel gear (116) and the fifth bevel gear (118) are fixedly connected with a second transmission shaft (119) and a third transmission shaft (120) respectively, the second transmission shaft (119) and the third transmission shaft (120) drive the crawling wheels (122) to rotate through a third intermediate transmission assembly (121) respectively.

4. A horizontal well wall perforating tool as defined in claim 2, wherein, The first variable-diameter mechanism comprises a second driving device (123), the second driving device (123) is fixedly connected with a first push rod (124), the first push rod (124) is fixedly connected with a center support (126) through a first elastic device (125), the center support (126) is rotatably connected with a suspension arm (127), the suspension arm (127) and a fixed support (128) are rotatably connected, and the fixed support (128) is fixedly connected with a crawling arm (129).

5. A horizontal well wall perforating tool as defined in claim 1, wherein, The anchoring centering short section (2) comprises a center shaft (210) arranged inside the anchoring centering short section (2) and a third driving device (201), the third driving device (201) is fixedly connected with a second push rod (202), the second push rod (202) is fixedly connected with an upper anchoring support (204) through a second elastic device (203), the upper anchoring support (204) is fixedly connected with an upper sliding block (205), the upper sliding block (205) is rotatably connected with an upper anchoring arm (206), the upper anchoring arm (206) is rotatably connected with a lower anchoring arm (207), the lower anchoring arm (207) is rotatably connected with a lower sliding block (208), the lower sliding block (208) is fixedly connected with a lower anchoring support (209), and the second elastic device (203) and the upper anchoring support (204) are slidably connected with the center shaft (210) and can slide axially along the center shaft (210).

6. A horizontal well wall perforating tool as defined in claim 1, wherein, The rotary connection short section (3) comprises a rotary shell (301), the rotary shell (301) is fixedly connected with a first rotary bearing (302) and a second rotary bearing (303) respectively, the rotary shell (301) and a split screw ring (304) are fixedly connected, and the split screw ring (304) is used to realize detachable connection of the rotary connection short section (3) and an adjacent short section.

7. A horizontal well wall perforating tool as defined in claim 1, wherein, The second shift drive mechanism structure is the same as the first shift drive mechanism, comprising a fourth driving device (401), a fourth transmission shaft (402), a second synchronous wheel (403), a second synchronous cover (404), a second shifting rod (405) and a second linear driving device (406), the fourth driving device (401) drives the fourth transmission shaft (402) to rotate, the fourth transmission shaft (402) is connected with the second synchronous wheel (403) and is rotatable but non-drivingly sleeved with the third spur gear (407) and the fourth spur gear (408), the second synchronous cover (404) is slidably connected with the second synchronous wheel (403) and rotates synchronously, the second synchronous cover (404) is connected with the second shifting rod (405), the second linear driving device (406) is connected with the second shifting rod (405) and is used for driving the second shifting rod (405) to move linearly in the axial direction, the second synchronous cover (404) can slide in the axial direction of the second synchronous wheel (403) under the pushing of the second shifting rod (405) to control the engagement of the third spur gear (407) and the fourth spur gear (408), the third spur gear (407) is power meshed with the fifth spur gear (410) through a fourth intermediate transmission assembly (409), the fifth spur gear (410) is fixedly connected with the anchoring and centering short section (2), the fourth spur gear (408) is power transmitted to the first perforated shell (412) of the eccentric perforating short section (4) through a fifth intermediate transmission assembly (411); The lower eccentric mechanism comprises a fifth driving device (413), the fifth driving device (413) drives a sixth spur gear (414) to rotate, and the sixth spur gear (414) is power transmitted to the first perforated shell (412) through a sixth intermediate transmission assembly (415).

8. A horizontal well wall perforating tool as defined in claim 7, wherein, The perforating mechanism comprises a hydraulic telescopic control device for controlling the telescopic movement of a drill bit (416) and a drill bit rotation control mechanism for controlling the rotation of the drill bit, the drill bit rotation control mechanism comprises a sixth driving device (417) for driving a sixth bevel gear (418) to rotate, the sixth bevel gear (418) is power meshed with a seventh bevel gear (419), the seventh bevel gear (419) is fixedly connected with a rotating seat (420), the rotating seat (420) is fixedly connected with the drill bit (416) through internal splines and is provided with a third elastic device (421) between the rotating seat (420) and the drill bit (416), the rotating seat (420) is rotatably connected with a fixed cover (423) through a third rotating bearing (422), and the fixed cover (423) is fixedly connected with the first perforated shell (412).

9. A horizontal well wall perforating tool as defined in claim 8, wherein, The hydraulic telescopic control device comprises an oil tank (424), a hydraulic pump (425), a one-way valve (426), a two-position three-way reversing valve (427), a pressure reducing valve (428), an accumulator (429) and a pilot overflow valve (430), the hydraulic pump (425) is communicated with the oil tank (424) through an oil circuit pipeline, and is used for providing a system pressure oil source; the hydraulic pump (425) is connected with the two-position three-way reversing valve (427) through an oil circuit pipeline, and a drill bit extension oil circuit is formed; the two-position three-way reversing valve (427) has two switching states, and is respectively used for controlling hydraulic oil to enter an extension cavity opening of the drill bit (416) and hydraulic oil in the extension cavity opening to flow back to the oil tank through the two-position three-way reversing valve (427); the hydraulic pump (425) is sequentially connected with the one-way valve (426), the pressure reducing valve (428), the accumulator (429) and the pilot overflow valve (430) through oil circuit pipelines, and a drill bit retraction oil circuit is formed; the drill bit retraction oil circuit is communicated with a retraction cavity opening of the drill bit (416) through a rotary sealing ring (431); and the rotary sealing ring (431) is rotationally connected with the rotary seat (420).

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