Rotary driving device with eccentric drill stem

Abstract

The invention belongs to the technical field of drilling engineering, and discloses a rotary driving device with an eccentric drill string, which can synchronously realize eccentric and rotary compound motion. Comprising a square tube rack, the drill stem rotating motor is fixed on the base; one end of the universal coupling is connected with the drill stem rotating motor, and the other end is connected with the eccentric rotator; the eccentric rotator is connected with the first short section drill column, the first short section drill column is connected with the second short section drill column through the sliding connector, and the second short section drill column is connected with the main drill column. The vertical guide mechanism is fixed on the square tube rack, is in sliding guide connection with the sliding joint, and allows the first short-section drill column to slide in the vertical direction while transmitting the rotating torque; and the lifting speed reducer assembly is used for driving the eccentric rotator to move in the vertical direction so as to drive the first short-section drill column to move up and down, so that the sliding connector is driven to slide up and down along the vertical guide mechanism, and the second short-section drill column, the first short-section drill column and an output shaft of the drill column rotating motor are always kept coaxial with the main drill column.

Description

Technical Field

[0001] The invention relates to the technical field of drilling engineering, and in particular to a rotary driving device with eccentricity for a drill string. Background Art

[0002] In the field of oil drilling, the efficiency of cuttings transport in extended-reach wells directly impacts drilling safety. The Drilling Rock Carrying Simulation Experimental Platform is a currently available experimental device used to study cuttings transport during drilling. Using this platform for drillstring eccentricity research can more conveniently and intuitively demonstrate the impact of drillstring eccentricity on rock transport during drilling.

[0003] However, existing drilling rock-carrying simulation test platforms can only simulate a single operating condition: drill string eccentricity or rotation; they cannot simultaneously achieve a combination of eccentricity and rotation. For example, existing drilling rock-carrying simulation test platforms simulate static eccentricity using a fixed eccentric block, but the drill string cannot rotate, or they can only rotate the drill string without dynamically adjusting the eccentricity. This results in significant deviations between experimental data and actual operating conditions, making it particularly difficult to study the behavior of cuttings transport under the coupled effects of drill string rotation and eccentricity. Furthermore, existing drilling rock-carrying simulation test platforms lack dynamic sealing designs when simulating eccentric motion, making leakage prone during drilling fluid circulation. Summary of the Invention

[0004] In order to enable the existing drilling rock-carrying simulation experimental platform to synchronously realize eccentric and rotational composite motion, the present invention proposes a rotary drive device capable of eccentrically driving a drill string.

[0005] The eccentric rotation drive device of the drill string according to the present invention comprises: a square tube frame; a drill string rotating motor fixed on the square tube frame; a universal joint, one end of which is connected to the output shaft of the drill string rotating motor and the other end is connected to the upper end of the eccentric rotator; the eccentric rotator, the lower end of which is connected to the first short section drill string, the first short section drill string is connected to the second short section drill string through a sliding joint, and the second short section drill string is connected to the main drill string; a vertical guide mechanism fixed on the square tube frame, the sliding joint is slidingly connected to the vertical guide mechanism to allow the first short section drill string to slide up and down in the vertical direction while transmitting rotational torque; and a lifting reducer assembly for driving the eccentric rotator to move up and down in the vertical direction to drive the first short section drill string to move up and down, thereby driving the sliding joint to slide up and down along the vertical guide mechanism, so that the second short section drill string, the first short section drill string and the output shaft of the drill string rotating motor always remain coaxial with the main drill string.

[0006] Furthermore, the vertical guide mechanism includes a guide rail section hoop fixed on the square tube bracket and formed with a central through hole, and a vertical guide rail fixed in the central through hole, and the sliding joint is in sliding cooperation with the vertical guide rail.

[0007] Furthermore, the sliding joint includes a shaft collar sleeved on the first short section drill string and a slider connected to the outer circumference of the shaft collar, and the slider is in sliding engagement with the vertical guide rail.

[0008] Furthermore, the eccentrically rotating drive device of the drill string also includes a sealing assembly, which includes a first flange connected to the guide rail section hoop and a second flange connected to the eccentric rotator, and a transparent silicone tube that is sealed between the first flange and the second flange and in which the first short section of the drill string is sleeved.

[0009] Furthermore, the lifting reducer assembly includes a lifting reducer connected to the bottom of the eccentric rotator, the output shaft of the lifting reducer is fixedly connected to the bottom of the eccentric rotator, a lifting drive motor connected to the input shaft of the lifting reducer, and a plurality of lifting optical shafts evenly distributed around the lifting reducer, the upper end of the lifting optical shaft passes through the housing of the eccentric rotator and forms a sliding pair for guiding and supporting the eccentric rotator.

[0010] Furthermore, the eccentric rotator includes an axial hole passing through the top of its shell, a rotating shaft rotatably connected in the axial hole, one end of the rotating shaft is connected to the universal joint, and the other end is connected to the first short section drill string. The circumferential side of the shell is evenly distributed with a plurality of guide hole groups for sliding cooperation with the lifting optical axis.

[0011] Furthermore, a drill string eccentric device is provided at the connection between the second short drill string and the main drill string, and the drill string eccentric device is used to adjust the axis of the main drill string and allow the main drill string and the second short drill string to rotate synchronously.

[0012] Furthermore, the drill string eccentric device includes a lifting eccentric structure, which includes a screw motor, a universal coupling, a plunger rod and an eccentric shaft ring. The eccentric shaft ring is sleeved at the connection between the second short section drill string and the main drill string. The second short section drill string and the main drill string can rotate in the eccentric shaft ring. One end of the plunger rod is connected to the eccentric shaft ring, and the other end is connected to the screw motor through the universal coupling. The screw motor drives the plunger rod to rise and fall vertically through the universal coupling to drive the eccentric shaft ring to rise and fall vertically, thereby driving the eccentric adjustment of the second short section drill string and the main drill string.

[0013] Furthermore, a transparent wellbore assembly is provided on the outside of the second short section drill string and the main drill string. The transparent wellbore assembly includes multiple transparent wellbores. Adjacent transparent wellbores are connected by wellbore joint collars. The plunger rod seal passes through the wellbore joint collar and is connected to the screw motor through a universal coupling. A discharge outlet tee is provided at the bottom of the transparent wellbore connected between the guide rail joint collar and the wellbore joint collar.

[0014] Furthermore, the main drill string includes multiple drill strings located in the transparent wellbore assembly, adjacent drill strings are threadedly connected, and the connection points of adjacent drill strings are all provided with lifting eccentric structures.

[0015] Compared with the prior art, the eccentric rotary drive device of the drill string of the present invention realizes high-precision, stepless, and online adjustable eccentricity control while the drill string rotates through four major innovations: independent drive of "rotation-eccentricity" dual motors, precise guidance of sliding joints and guide rails, flexible sealing of transparent silicone tubes, and stepless adjustment of external screw rods and plunger rods. It has zero leakage and visualization throughout the process, and can be expanded to multi-drill string and multi-point eccentricity experiments. Under the premise of maintaining high-pressure drilling fluid circulation, it can accurately reproduce the cuttings migration environment of large-displacement wells, solve the long-standing technical problem of unreliable dynamic eccentricity simulation in the drilling engineering field, and provide a revolutionary experimental platform for optimizing wellbore cleaning efficiency. The integrated design of the guide rail section hoop and the lifting optical axis increases the overall stiffness by several times and greatly reduces vibration. Maintenance only requires external adjustment of the screw motor without disassembly of the wellbore, which greatly improves maintenance efficiency, covers a wide range of experimental conditions, and the experimental data is closer to real drilling. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 2. It is a schematic diagram of the three-dimensional structure of the eccentric rotary driving device of the drill string according to an embodiment of the present invention;

[0017] Figure 2 A schematic front view of the structure of a rotary drive device for an eccentric drill string according to an embodiment of the present invention;

[0018] Figure 3 for Figure 1 The structural diagram of the guide rail hoop shown;

[0019] Figure 4 for Figure 1 The structural diagram of the eccentric rotator shown;

[0020] Figure 5 2. A diagram showing the working principle of a rotary drive device for an eccentric drill string according to an embodiment of the present invention;

[0021] Figure 6 for Figure 1 The structural diagram of the drill string eccentric device shown;

[0022] Figure 7 for Figure 6 The installation diagram of the drill string eccentric device is shown. DETAILED DESCRIPTION

[0023] In order to better understand the purpose, structure and function of the present invention, the present invention is further described in detail below with reference to the accompanying drawings.

[0024] Figure 1 and Figure 2 FIG. 1 shows the structure of a rotary driving device 100 for eccentrically rotating a drill string according to an embodiment of the present invention. Figure 1 and Figure 2As shown, the drill string eccentric rotation drive device 100 may include: a square tube frame 10; a drill string rotating motor 20 fixed to the square tube frame 10, and the drill string rotating motor 20 can be fixed to the square tube frame 10 through a rotating motor bracket 21; a universal joint 30, one end of which is connected to the output shaft of the drill string rotating motor 20, and the other end is connected to the upper end of the eccentric rotator 40; the lower end of the eccentric rotator 40 is connected to the first short drill string 70, the first short drill string 70 is connected to the second short drill string 80 through a sliding joint 62, and the second short drill string 80 is connected to the main drill string 3; fixed The vertical guide mechanism 60 on the square tube frame 10, the sliding joint 62 is connected to the vertical guide mechanism 60 in a sliding guide manner to allow the first short section drill string 70 to slide up and down in the vertical direction while transmitting the rotational torque; and the lifting reducer assembly 9 is used to drive the eccentric rotator 40 to move up and down in the vertical direction to drive the first short section drill string 70 to move up and down, thereby driving the sliding joint 62 to slide up and down along the vertical guide mechanism, so that the second short section drill string 80, the first short section drill string 70 and the output shaft of the drill string rotation motor 20 always remain coaxial with the main drill string 3.

[0025] The eccentric rotary drive device 100 of the drill string of the embodiment of the present invention is combined with the Figure 5 As shown, the torque of the drill string rotation motor 20 is transmitted to the eccentric rotator 40 through the universal joint 30, driving the first short section drill string 70 to rotate; at the same time, the lifting reducer assembly 9 pushes the eccentric rotator 40 to lift vertically, driving the first short section drill string 70 to move up and down. At this time, the sliding joint 62 is constrained by the vertical guide mechanism 60 to slide along the preset trajectory, forcing the second short section drill string 80 to lift vertically, thereby achieving drill string rotation and dynamic eccentric motion synchronously while maintaining the coaxiality of the entire drill string system.

[0026] In the drill string eccentric rotation drive device 100 of the embodiment of the present invention, the rotational torque is transmitted through the universal joint 30, while the eccentric rotator 40 is allowed to rise and fall, realizing the synchronous operation of the drill string rotation and eccentric motion. The universal joint 30 compensates for the axis deviation caused by the lifting displacement, breaking through the technical bottleneck of the interference between rotation and eccentric motion. The sliding joint 62 cooperates with the vertical guide mechanism 60, and the vertical guide mechanism 60 accurately constrains the trajectory of the sliding joint 62, ensuring that the entire drill string system always maintains coaxiality during eccentric motion, avoiding motion interference, thereby ensuring the continuity of power transmission and experimental reliability. The drill string eccentric rotation drive device 100 of the embodiment of the present invention is the first to reproduce the combined motion of drill string rotation and eccentricity under drilling fluid circulation conditions, providing a high-fidelity experimental platform for real-world working condition simulation for cuttings transport research.

[0027] In such Figure 3In the preferred embodiment shown, the vertical guide mechanism 60 may include a guide rail collar fixed to the square tube support 10 and having a central through-hole formed therein. The guide rail collar may be secured to the square tube support 10 via a guide rail collar fixture 61, and a vertical guide rail 63 secured within the central through-hole. A sliding joint 62 slidably engages with the vertical guide rail 63. In this embodiment, the vertical guide rail 63 within the guide rail collar provides a precise linear constraint for the sliding joint 62, eliminating lateral offset errors. The central through-hole design facilitates the passage of the drill string system and helps enhance the guide rail collar's ability to resist deformation, adapting to high-frequency lifting conditions.

[0028] Further, if Figure 3 As shown, the sliding joint 62 may include a collar 621 mounted on the first drill string sub 70 and a slider 622 connected to the outer periphery of the collar 621. The slider 622 slides with the vertical guide rail 63. The collar 621 is designed to facilitate the transmission of rotational torque, while the slider 622 independently performs the vertical guidance function to avoid mutual interference.

[0029] Preferably, if Figure 3 As shown, the vertical guide rail 63 may include two guide rails fixed in parallel and spaced apart in the central through hole, and the sliding joint 62 may include two opposing sliders 622 connected to the outer periphery of the shaft ring 621. The symmetrical design of the double sliders helps to balance the side load, reduce guide rail wear, and improve movement smoothness.

[0030] In such Figure 1 In the preferred embodiment shown, the eccentrically rotatable drill string drive device 100 may further include a sealing assembly 50. The sealing assembly 50 may include a first flange connected to the guide rail collar, a second flange connected to the eccentric rotator 40, and a transparent silicone tube 501 sealingly connected between the first and second flanges and housing the first short drill string section 70. The transparent silicone tube 501 (preferably a deformable flexible tube) is capable of adaptively expanding and contracting during eccentric lifting to maintain sealing, isolating the drilling fluid and allowing eccentric movement of the first short drill string section 70.

[0031] In a preferred embodiment, Figure 3As shown, two parallel guide rails divide the central through hole into a middle moving area and empty areas on both sides. A sealing plate assembly may also be provided in the central through hole in the guide rail section hoop. The sealing plate assembly may include a sealing baffle sealed and fixed in the empty areas on both sides, and a telescopic baffle assembly located in the middle moving area. The telescopic baffle assembly is constructed so that the sliding joint 62 always keeps the middle moving area blocked when it moves up and down along the vertical guide rail 63. In a preferred embodiment, the telescopic baffle assembly may include an upper telescopic baffle and a lower telescopic baffle connected to the upper and lower opposite sides of the shaft ring 621. The upper and lower ends of the inner peripheral wall of the guide rail section hoop are respectively provided with an upper groove and a lower groove. An upper spring member is fixed in the upper groove, and a lower spring member is fixed in the lower groove. The upper telescopic baffle and the lower telescopic baffle are fixedly connected to the upper spring member and the lower spring member respectively. When the sliding joint 62 slides upward along the vertical guide rail 63, the lower telescopic baffle stretches the lower spring member to move upward, and the upper telescopic baffle compresses the upper spring member to move upward in the groove. The sliding joint 62 can be moved up and down along the vertical guide rail 63, and the telescopic baffle assembly can always block the middle moving area of ​​the central through hole. At the same time, the sealing baffle can block the vacant areas on both sides of the central through hole, thereby preventing the fluid on the side of the second short section drill string 80 from entering the transparent silicone tube 501 through the central through hole of the guide rail joint hoop. On the one hand, this arrangement allows the fluid on the side of the second short section drill string 80 to flow out directly through the discharge outlet tee 101 described below, and on the other hand, it can also protect the structure of the first short section drill string 70 and the transparent silicone tube 501.

[0032] In such Figure 1 and Figure 2 In the preferred embodiment shown, the lifting reducer assembly 9 may include a lifting reducer 91 connected to the bottom of the eccentric rotator 40, the output shaft of the lifting reducer 91 being fixedly connected to the bottom of the eccentric rotator 40, a lifting drive motor 92 connected to the input shaft of the lifting reducer 91, and a plurality of lifting optical shafts 404 evenly distributed around the lifting reducer 91. The upper ends of the lifting optical shafts 404 penetrate the housing of the eccentric rotator 40 and form a sliding pair for guiding and supporting the eccentric rotator 40. The multiple evenly distributed lifting optical shafts 404 (preferably four) constitute a redundant guide system to prevent the eccentric rotator 40 from tilting and to ensure smoother lifting.

[0033] In such Figure 4In the preferred embodiment shown, the eccentric rotator 40 may include an axial hole 402 extending through the top of its housing 401, and a rotating shaft 403 rotatably connected within the axial hole 402. One end of the rotating shaft 403 is connected to the universal joint 30, and the other end is connected to the first drill string sub 70. Multiple guide hole groups are uniformly distributed around the circumference of the housing 401 for sliding engagement with the lifting shaft 404. In this embodiment, the rotating shaft 403 can be isolated from the housing 401 by bearings, independently transmitting torque and performing lifting motion. The guide hole groups and the lifting shaft 404 form a multiple sliding pair to resist drilling fluid impact loads.

[0034] According to the present invention, Figure 1 and Figure 2 In the preferred embodiment shown, a drill string eccentric device 4 is provided at the connection between the second drill string sub 80 and the main drill string 3. The drill string eccentric device 4 is used to adjust the axis of the main drill string 3 and allow the main drill string 3 and the second drill string sub 80 to rotate synchronously. The provision of the drill string eccentric device 4 is used to achieve dynamic adjustment of the axis of the main drill string 3 to simulate different drill pipe eccentricity conditions.

[0035] In such Figure 6 In the preferred embodiment shown, the drill string eccentric device 4 may include a screw motor 41, a universal coupling 42, a plunger rod 43 and an eccentric shaft ring 44. The eccentric shaft ring 44 is sleeved at the connection between the second short section drill string 80 and the main drill string 3. The second short section drill string 80 and the main drill string 3 can rotate in the eccentric shaft ring 44. One end of the plunger rod 43 is connected to the eccentric shaft ring 44, and the other end is connected to the screw motor 41 through the universal coupling 42. The screw motor 41 drives the plunger rod 43 to rise and fall vertically through the universal coupling 42, so as to drive the eccentric shaft ring 44 to rise and fall vertically, thereby driving the eccentric adjustment of the second short section drill string 80 and the main drill string 3. In this embodiment, the screw motor 41 drives the plunger rod 43 to rise and fall vertically through the universal coupling 42, driving the eccentric shaft ring 44 and the drill string to achieve 0-100% eccentricity, thereby realizing continuous, stepless, and precisely quantifiable eccentricity adjustment of the drill string to cover all working conditions. The universal coupling 42 only allows the plunger rod 43 to rise and fall vertically, eliminating lateral bending moment, so that the plunger rod 43 can rise and fall more smoothly.

[0036] Further, if Figure 6As shown, the lifting eccentric structure 4 may further include a base 48 having a through hole and the above-mentioned motor bracket 45 fixedly connected to the top of the base 48, the screw motor 41 is fixed to the top of the motor bracket 45, and a plunger sealing shaft hole member 49 sealedly connected to the through hole is installed in the base 48. The bottom end of the plunger rod 43 passes through the motor bracket 45 and enters the shaft hole of the plunger sealing shaft hole member 49 and is sealed and slidably connected thereto. The top end of the plunger rod 43 is connected to the screw of the screw motor 41 through the universal coupling 42. This embodiment enables the plunger rod 43 to be stably lifted and lowered in the vertical direction by adding a modular sealing unit of the base 48 and the plunger sealing shaft hole member 49 located therein, and the plunger sealing shaft hole member 49 can be quickly replaced, thereby improving maintenance efficiency.

[0037] Preferably, if Figure 6 As shown, a plunger seal ring 431 may be provided between the plunger rod 43 and the shaft hole, a seal ring 491 may be provided between the base 48 and the plunger sealing shaft hole member 49, and a dust ring 492 may be provided at the bottom of the inner wall of the shaft hole of the plunger sealing shaft hole member 49. The plunger seal ring 431 and the dust ring 492 form a first seal between the plunger rod 43 and the shaft hole, and the seal ring 491 forms a second seal between the base 48 and the plunger sealing shaft hole member 49. This double seal can prevent rock debris from intruding into the base 48, prevent the plunger rod 43 from getting stuck, and extend the life of the device.

[0038] In such Figure 6 In the preferred embodiment shown, the lifting eccentric structure 4 may further include a lifting ring 40 connected between the plunger rod 43 and the eccentric shaft ring 44. The provision of the lifting ring 40 can reduce the contact area with the drilling fluid, avoid collision damage of rock cuttings, and maintain the authenticity of fluid flow.

[0039] In such Figure 6 In the preferred embodiment shown, the connection between the second drill string sub 80 and the main drill string 3 can be mounted within the eccentric collar 44 via a bearing assembly. A mounting groove for the bearing assembly can be formed on the outer peripheral wall of the connection between the second drill string sub 80 and the main drill string 3. The bearing assembly can include a first bearing 81 located at the center of the mounting groove, second bearings 82 located at either end of the mounting groove 31, and a retaining ring 83 mounted between the first and second bearings 81 and 82. The eccentric collar 44 can be formed with a first annular groove for engaging the first bearing 81, a second annular groove for engaging the second bearing 82, and a third annular groove for engaging the retaining ring 83. This embodiment, through the design of a composite positioning structure of "dual bearings + retaining ring + three-way annular groove," not only ensures that the drill string does not move axially even at high rotational speeds, but also provides distributed load-bearing support, preventing the drill string from tilting or jamming during eccentric lifting and lowering, ensuring smooth movement. Furthermore, it ensures assembly coaxiality, avoiding the wobble associated with a single-bearing cantilever structure.

[0040] In such Figure 7 In the preferred embodiment shown, the wellbore joint hoop 2 may include a joint hoop adjustment base plate 71 connected to the bottom of the wellbore joint hoop 2 and a joint hoop mounting base plate 72 located below the joint hoop adjustment base plate 71, and an adjusting screw assembly 73 connected between the joint hoop adjustment base plate 71 and the joint hoop mounting base plate 72. The adjusting screw assembly 73 is used to adjust the height of the wellbore joint hoop 2 by adjusting the height of the joint hoop adjustment base plate 71 relative to the joint hoop mounting base plate 72, so as to adjust the concentricity of the multi-section transparent wellbore 1, and to solve the problem of axial deviation of the splicing of multiple sections of transparent wellbore 1, and ensure that the inner wall forms a continuous concentric cylinder.

[0041] In such Figure 1 and Figure 7 In the preferred embodiment shown, a transparent wellbore assembly is sheathed around the exterior of the second short drill string 80 and the main drill string 3. The transparent wellbore assembly may include multiple transparent wellbores 1. Adjacent transparent wellbores 1 may be connected via wellbore collars 2. A plunger rod 43 sealably passes through the wellbore collar 2 and is connected to a lead screw motor 41 via a universal coupling 42. A discharge tee 101 is provided at the bottom of the transparent wellbore 1, connected between the guide collar and the wellbore collar. The transparent wellbore assembly is designed to recreate the actual wellhead and wellbore structure. The discharge tee 101 allows cuttings to be discharged from the test section, collected, and then reinjected for reuse.

[0042] Furthermore, the main drill string 3 may include multiple drill strings located in the transparent wellbore assembly, adjacent drill strings are threadedly connected, and the connection points of adjacent drill strings are all provided with the above-mentioned lifting eccentric structure 4 for realizing the rotational eccentricity simulation of the long drill string.

[0043] like Figure 5 As shown, the operating principles of the drill string eccentric rotation drive device 100 of the present invention include the following four aspects: 1) Rotational drive: The torque transmission chain is drill string rotation motor 20 → universal joint 30 → eccentric rotator 40 → first drill string short section 70 → sliding joint 62 → second drill string short section 80 → main drill string 3. 2) Eccentricity adjustment: The lifting reducer 91 drives the eccentric rotator 40 to move up and down as a whole, and the sliding joint 62 slides along the vertical guide rail within the guide rail section clamp of the vertical guide mechanism 60. Simultaneously, the screw motor 41 at the connection of each drill string section drives the eccentric shaft ring 44 to rise and fall synchronously through the universal joint 42 and plunger rod 43, achieving eccentricity adjustment of the entire drill string system. 3) Sealing and circulation: The transparent silicone tube 501 adaptively expands and contracts with the eccentric movement, isolating the drilling fluid; rock cuttings flow downward along the transparent wellbore assembly and return to the pumping system through the outlet tee 101. The entire experimental process is visualized. 4) Multi-point expansion: The lifting eccentric structure 4 is repeatedly installed at each connection of the long drill string, and any spatial eccentricity curve can be programmed to simulate the complex wellbore trajectory of horizontal wells and extended reach wells.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A rotary drive device for a drill string capable of eccentric rotation, characterized in that: include: Square tube rack; A drill string rotating motor fixed on the square tube frame; A universal joint, one end of which is connected to the output shaft of the drill string rotating motor and the other end of which is connected to the upper end of the eccentric rotator; The eccentric rotator has a lower end connected to a first short drill string, the first short drill string is connected to a second short drill string via a sliding joint, and the second short drill string is connected to the main drill string; A vertical guide mechanism fixed to the square tube frame, wherein the sliding joint is slidably and guidely connected to the vertical guide mechanism to allow the first short drill string to slide up and down in the vertical direction while transmitting rotational torque; as well as The lifting reducer assembly is used to drive the eccentric rotator to move up and down in the vertical direction, so as to drive the first short-section drill string to move up and down, thereby driving the sliding joint to slide up and down along the vertical guide mechanism, so that the output shaft of the second short-section drill string, the first short-section drill string and the drill string rotation motor always remains coaxial with the main drill string.

2. The eccentric rotary drive device for a drill string according to claim 1, characterized in that: The vertical guide mechanism includes a guide rail section hoop fixed on the square tube bracket and formed with a central through hole, and a vertical guide rail fixed in the central through hole, and the sliding joint is in sliding cooperation with the vertical guide rail.

3. The eccentrically rotatable driving device for a drill string according to claim 2, characterized in that: The sliding joint includes a shaft collar sleeved on the first short section drill string and a sliding block connected to the outer periphery of the shaft collar, and the sliding block is in sliding cooperation with the vertical guide rail.

4. The eccentric rotary drive device for a drill string according to claim 2, characterized in that: The eccentrically rotating drive device of the drill string also includes a sealing assembly, which includes a first flange connected to the guide rail section collar and a second flange connected to the eccentric rotator, and a transparent silicone tube that is sealed between the first flange and the second flange and in which the first short section drill string is sleeved.

5. The eccentric rotary driving device for a drill string according to any one of claims 1 to 4, characterized in that: The lifting reducer assembly includes a lifting reducer connected to the bottom of the eccentric rotator, the output shaft of the lifting reducer is fixedly connected to the bottom of the eccentric rotator, a lifting drive motor connected to the input shaft of the lifting reducer, and a plurality of lifting optical shafts evenly distributed around the lifting reducer, the upper ends of the lifting optical shafts pass through the housing of the eccentric rotator and form a sliding pair for guiding and supporting the eccentric rotator.

6. The eccentrically rotatable driving device for a drill string according to claim 5, characterized in that: The eccentric rotator includes an axial hole passing through the top of its shell, a rotating shaft rotatably connected to the axial hole, one end of the rotating shaft is connected to the universal joint, and the other end is connected to the first short-section drill string. The circumference of the shell is evenly distributed with a plurality of guide hole groups for sliding cooperation with the lifting optical axis.

7. The eccentrically rotatable driving device for a drill string according to any one of claims 2 to 4, characterized in that: A drill string eccentric device is provided at the connection between the second short drill string and the main drill string. The drill string eccentric device is used to adjust the axis of the main drill string and allow the main drill string and the second short drill string to rotate synchronously.

8. The eccentrically rotatable driving device for a drill string according to claim 7, wherein: The drill string eccentric device includes a lifting eccentric structure, which includes a screw motor, a universal coupling, a plunger rod and an eccentric shaft ring. The eccentric shaft ring is sleeved at the connection between the second short section drill string and the main drill string. The second short section drill string and the main drill string can rotate in the eccentric shaft ring. One end of the plunger rod is connected to the eccentric shaft ring, and the other end is connected to the screw motor through the universal coupling. The screw motor drives the plunger rod to rise and fall vertically through the universal coupling, so as to drive the eccentric shaft ring to rise and fall vertically, thereby driving the eccentric adjustment of the second short section drill string and the main drill string.

9. The eccentrically rotatable driving device for a drill string according to claim 8, characterized in that: A transparent wellbore assembly is provided on the outside of the second short-section drill string and the main drill string. The transparent wellbore assembly includes multiple transparent wellbores. Adjacent transparent wellbores are connected by wellbore joint collars. The plunger rod seal passes through the wellbore joint collar and is connected to the screw motor through the universal coupling. A discharge outlet tee is provided at the bottom of the transparent wellbore connected between the guide rail joint collar and the wellbore joint collar.

10. The eccentrically rotatable driving device for a drill string according to claim 9, characterized in that: The main drill string includes a plurality of drill strings located in the transparent wellbore assembly. Adjacent drill strings are threadedly connected, and the connection points of adjacent drill strings are all provided with the lifting eccentric structure.

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