Shale oil well staged fracturing soluble bridge plug delivery device

Abstract

The invention discloses a delivery device for a shale oil well staged fracturing soluble bridge plug, and relates to the technical field of shale oil exploitation. The device comprises lifting equipment, a cable is wound on the surface of the lifting equipment, the other end of the cable is fixedly connected with a setting tool, and the surface of the setting tool is sleeved with a fixing ring; a driving assembly is arranged on the surface of the fixing ring and comprises a sealing ring fixedly connected to the bottom of the fixing ring. A single servo motor is matched with a planetary gear and bevel gear transmission system, strict synchronous rotation of the three driving wheels is achieved, thrust consistency is kept, the problem of asynchronism existing in multi-motor driving is solved, the driving wheels have the radial displacement capacity through a worm and spring self-adaption system, and when a borehole diameter changes or a protruding obstacle occurs, the driving wheels can be driven by the worm and spring self-adaption system. The spring adjusts the contact pressure of the driving wheel in real time and is matched with axial sliding of the worm in the sliding groove, it is ensured that the driving wheel always keeps the best contact state with the well wall, and the propelling efficiency is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of shale oil extraction, and particularly relates to a soluble bridge plug delivery device for staged fracturing of shale oil wells. Background Art

[0002] During the process of shale oil extraction, the staged fracturing technology is the core process to improve the recovery rate, and the precise delivery of soluble bridge plugs is the key link. A soluble bridge plug is a downhole tool made of degradable materials (such as magnesium alloy, special polymer), which is used to temporarily seal the wellbore. Its characteristic is that after completing the sealing task, it can dissolve itself under the action of formation temperature, pressure or specific fluid, without mechanical drilling, saving operation time and cost.

[0003] Existing delivery devices mostly adopt the method of cable traction combined with mechanical pushing, but problems such as uneven pushing force and poor adaptability often occur under complex well conditions. Especially in the horizontal well section or areas with large changes in well diameter, when the well diameter changes or there are protrusions on the wellbore wall, it will cause the contact pressure of the pushing device to be unbalanced, resulting in a decrease in the delivery efficiency. Moreover, existing equipment is prone to jamming and pushing failure, seriously affecting the fracturing operation efficiency.

[0004] Therefore, we provide a soluble bridge plug delivery device for staged fracturing of shale oil wells to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a soluble bridge plug delivery device for staged fracturing of shale oil wells, which solves the problems of uneven thrust and poor well condition adaptability of the soluble bridge plug delivery device for staged fracturing of shale oil wells in the prior art through the cooperation of a driving component and an adaptive component.

[0006] To solve the above technical problems, the present invention is realized through the following technical solutions.

[0007] The present invention is a soluble bridge plug delivery device for staged fracturing of shale oil wells, including a hoisting device. A cable is wound around the surface of the hoisting device, and the other end of the cable is fixedly connected to a setting tool. A fixing ring is sleeved on the surface of the setting tool; a driving component is arranged on the surface of the fixing ring. The driving component includes a sealing ring fixedly connected to the bottom of the fixing ring, a fixing cylinder fixedly connected to the top of the sealing ring, a driving cylinder movably connected to the surface of the fixing ring through a bearing seat, a through hole opened on the surface of the fixing cylinder, a protective cylinder arranged in the inner cavity of the through hole, and a driving wheel movably connected to the inner wall of the protective cylinder through a bearing seat; an adaptive component is arranged on the surface of the fixing cylinder. The adaptive component includes a spring sleeved on the surface of the protective cylinder, a retaining ring fixedly connected to the surface of the protective cylinder, a worm movably connected to the inner wall of the protective cylinder through a bearing seat, and a movable sleeve sleeved on one end of the worm.

[0008] The present invention is further configured such that a servo motor is fixedly connected to the surface of the fixed cylinder through a mounting block. The output shaft of the servo motor is fixedly connected to a first gear. A second gear is engaged with one side of the first gear. The center of the second gear is fixedly connected to the surface of the drive cylinder. The servo motor is mounted on the stiffening rib plate of the fixed cylinder through a flange. The end of its output shaft is fixedly installed with a first gear. The first gear and the second gear are engaged with each other. The center of the second gear is fixedly connected to the drive cylinder, forming a planetary gear transmission structure, which is convenient for providing power to the three drive wheels.

[0009] The present invention is further configured such that a first bevel gear is fixedly connected to the surface of the drive cylinder. A second bevel gear is engaged with the surface of the first bevel gear. The center of the second bevel gear is fixedly connected to the surface of the movable sleeve. The center of the second bevel gear is fixedly connected to the movable sleeve. The inner wall of the movable sleeve is slidably connected to the worm through a chute and slider structure. The end of the worm is engaged with a worm gear. The worm gear is coaxially arranged with the drive wheel. The first bevel gear and the second bevel gear convert the rotational motion into the power output in the vertical direction.

[0010] The present invention is further configured such that a chute is provided in the inner cavity of the movable sleeve. A slider is fixedly connected to the surface of the worm. The slider is slidably connected in the inner cavity of the chute. The chute on the inner wall of the movable sleeve allows the worm to freely slide within the axial displacement range, while restricting the circumferential rotation.

[0011] The present invention is further configured such that a worm gear is engaged with the surface of the worm. The center of the worm gear is fixedly connected to the surface of the drive wheel. The worm and the worm gear have a self-locking structure. When the power supply is stopped, the drive wheel can be immediately locked to prevent the device from sliding down in the inclined well section.

[0012] The present invention is further configured such that one end of the spring is fixedly connected to the surface of the fixed cylinder, and the other end of the spring is fixedly connected to one side of the retaining ring. The spring can provide a continuous pre-tightening force to the protective sleeve, making it closely adhere to the inner wall of the wellbore to ensure the stable operation of the device in the wellbore.

[0013] The present invention is further configured such that a threaded hole is provided on the surface of the fixed ring, and a clamping bolt is threadedly connected to the inner cavity of the threaded hole. The clamping bolt adopts an internal hexagonal countersunk head design, and the threaded part is coated with high-temperature anaerobic glue. The three-point clamping structure can generate a radial clamping force to ensure that the setting tool does not undergo axial displacement, and at the same time, it is convenient to temporarily fix the setting tool to the fixed ring for facilitating the transportation of the setting tool.

[0014] The present invention is further configured such that a ball bearing is fixedly connected to the surface of the movable sleeve. The outer ring of the ball bearing is fixedly connected to an L-shaped block. The other end of the L-shaped block is fixedly connected to the inner surface of the fixed cylinder. The cooperation of the L-shaped block and the ball bearing realizes the axial positioning of the movable sleeve to ensure the accuracy of the axial movement of the worm.

[0015] The present invention is further configured such that the number of driving wheels is three, and friction blocks are provided on the surfaces of all three driving wheels. The friction blocks on the driving wheel surfaces are arranged in a diamond grid pattern, and the friction blocks protrude from the driving wheel surfaces to generate a controllable micro-cutting effect when contacting the wellbore wall, ensuring the traction force.

[0016] The present invention is further configured such that a perforating device is provided at the bottom of the setting tool, and a soluble bridge plug body is provided at the other end of the perforating device.

[0017] The present invention has the following beneficial effects.

[0018] 1. Through the cooperation of a single servo motor with a planetary gear and bevel gear transmission system, the present invention realizes the strictly synchronous rotation of three driving wheels, maintains the consistency of the thrust, and solves the problem of asynchronism existing in multi-motor drive. The worm and spring adaptive system enables the driving wheels to have the ability of radial displacement. When encountering changes in well diameter or convex obstacles, the spring adjusts the contact pressure of the driving wheels in real time, and cooperates with the axial sliding of the worm in the chute to ensure that the driving wheels always maintain the best contact state with the wellbore wall and maintain the propulsion efficiency.

[0019] 2. Through the design of the circumferential uniform distribution of three driving wheels at 120 degrees and diamond friction blocks, the present invention forms a stable three-point support structure. When operating in the inclined well section, the self-locking characteristics of the worm and worm gear can withstand the downward sliding force generated by the well inclination angle within the allowable range, and cooperate with the redundant cable winding system to ensure the operation stability of the device under complex well conditions.

[0020] 3. Through the design of the sealing ring and protective cylinder, the present invention achieves high protection performance. The movable sleeve is internally provided with a ball bearing structure, which reduces the wear rate of transmission components, extends the continuous operation time of the device, and the worm and worm gear transmission design realizes the self-locking function of the driving wheels, and can withstand a certain wellbore impact load in the state of the stopped motor.

[0021] Of course, it is not necessary for any product implementing the present invention to achieve all the above-mentioned advantages simultaneously. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below.

[0023] Figure 1 It is a three-dimensional view of a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0024] Figure 2 It is a mating diagram of a fixing ring and a fixing cylinder in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0025] Figure 3 It is a top view of a fixing ring in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0026] Figure 4 It is a mating diagram of a first gear and a second gear in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0027] Figure 5 It is a mating diagram of a first bevel gear and a second bevel gear in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0028] Figure 6 It is a mating diagram of a worm and a movable sleeve in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0029] Figure 7 It is a mating diagram of a chute and a slider in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0030] Figure 8 It is a mating diagram of a worm and a worm gear in a soluble bridge plug delivery device for staged fracturing of shale oil wells.

[0031] In the attached drawings: 1, lifting equipment; 2, cable; 3, setting tool; 4, fixing ring; 5, sealing ring; 6, fixing cylinder; 7, driving cylinder; 8, through hole; 9, protective cylinder; 10, driving wheel; 11, spring; 12, retaining ring; 13, worm; 14, movable sleeve; 15, servo motor; 16, first gear; 17, second gear; 18, first bevel gear; 19, second bevel gear; 20, chute; 21, slider; 22, worm gear; 23, clamping bolt; 24, ball bearing; 25, L-shaped block; 26, friction block; 27, perforating equipment; 28, soluble bridge plug body. Detailed implementation manners

[0032] Next, the technical solutions in the embodiments of the present invention will be described in conjunction with the accompanying drawings in the embodiments of the present invention. The described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments.

[0033] Embodiment 1

[0034] Please refer to Figures 1 - 8, the present invention is a soluble bridge plug delivery device for staged fracturing of shale oil wells, including a hoisting device 1. A cable 2 is wound around the surface of the hoisting device 1. The other end of the cable 2 is fixedly connected to a setting tool 3, and a fixing ring 4 is sleeved on the surface of the setting tool 3; a driving assembly is arranged on the surface of the fixing ring 4. The driving assembly includes a sealing ring 5 fixedly connected to the bottom of the fixing ring 4, a fixing cylinder 6 fixedly connected to the top of the sealing ring 5, a driving cylinder 7 movably connected to the surface of the fixing ring 4 through a bearing seat, a through hole 8 opened on the surface of the fixing cylinder 6, a protective cylinder 9 arranged in the inner cavity of the through hole 8, and a driving wheel 10 movably connected to the inner wall of the protective cylinder 9 through a bearing seat; an adaptive assembly is arranged on the surface of the fixing cylinder 6. The adaptive assembly includes a spring 11 sleeved on the surface of the protective cylinder 9, a retaining ring 12 fixedly connected to the surface of the protective cylinder 9, a worm 13 movably connected to the inner wall of the protective cylinder 9 through a bearing seat, and a movable sleeve 14 sleeved on one end of the worm 13.

[0035] Further supplement, the cable 2 is wound around the drum in two strands to form a redundant traction system, and the cable 2 is wound in a symmetric spiral manner to ensure torque balance during the lowering process. This design enables the device to maintain a low-angle attitude deviation during high-depth well operations. The three driving wheels 10 are circumferentially evenly distributed at 120 degrees on the outside of the fixing cylinder 6. This layout enables the device to generate sufficient propulsion force in the wellbore and at the same time ensures its adaptive ability under wellbore deviation. The driving cylinder 7 and the fixing cylinder 6 are coaxially arranged, and the surface of the driving cylinder 7 is linked with the movable sleeve 14 through a transmission mechanism of a first bevel gear 18 and a second bevel gear 19. Each driving wheel 10 is connected to the movable sleeve 14 through the second bevel gear 19. The movable sleeve 14 rotates synchronously with the driving cylinder 7 through a worm gear 22 and a worm 13, realizing coaxial and same-speed rotation of the three driving wheels 10. The power transmission system adopts a combined transmission of planetary gears and bevel gears, with a small thrust consistency error, ensuring the stable operation of the device.

[0036] Embodiment 2

[0037] Please refer to Figures 1 - 8 , on the basis of Embodiment 1, a servo motor 15 is fixedly connected to the surface of the fixing cylinder 6 through a mounting block. The output shaft of the servo motor 15 is fixedly connected to a first gear 16. A second gear 17 is meshed on one side of the first gear 16. The center of the second gear 17 is fixedly connected to the surface of the driving cylinder 7. A first bevel gear 18 is fixedly connected to the surface of the driving cylinder 7. A second bevel gear 19 is meshed on the surface of the first bevel gear 18. The center of the second bevel gear 19 is fixedly connected to the surface of the movable sleeve 14. A chute 20 is arranged in the inner cavity of the movable sleeve 14. A slider 21 is fixedly connected to the surface of the worm 13. The slider 21 is slidably connected in the inner cavity of the chute 20. A worm gear 22 is meshed on the surface of the worm 13. The center of the worm gear 22 is fixedly connected to the surface of the driving wheel 10.

[0038] Further supplement, the servo motor 15 is mounted on the reinforcing rib plate of the fixed cylinder 6 through a flange, and a first gear 16 is fixedly installed at the end of its output shaft. The first gear 16 meshes with the second gear 17, and the center of the second gear 17 is fixedly connected to the driving cylinder 7, forming a planetary gear transmission structure, which is convenient for providing power to the three driving wheels 10. The center of the second bevel gear 19 is fixedly connected to the movable sleeve 14. The inner wall of the movable sleeve 14 is slidably connected to the worm 13 through a chute 20 and a slider 21 structure. The end of the worm 13 meshes with a worm gear 22, and the worm gear 22 is coaxially arranged with the driving wheel 10. The first bevel gear 18 and the second bevel gear 19 convert the rotational motion into power output in the vertical direction. The chute 20 on the inner wall of the movable sleeve 14 allows the worm 13 to freely slide within the axial displacement range while restricting circumferential rotation. The worm gear 22 and the worm 13 have a self-locking structure, which can immediately lock the driving wheel 10 when the power supply is stopped, preventing the device from sliding down in the inclined well section.

[0039] Embodiment 3

[0040] Please refer to Figures 1 - 8 , on the basis of Embodiment 1 and Embodiment 2, one end of the spring 11 is fixedly connected to the surface of the fixed cylinder 6, and the other end of the spring 11 is fixedly connected to one side of the retaining ring 12. Threaded holes are formed on the surface of the fixing ring 4, and a clamping bolt 23 is threadedly connected to the inner cavity of the threaded hole. A ball bearing 24 is fixedly connected to the surface of the movable sleeve 14, and an L-shaped block 25 is fixedly connected to the outer ring of the ball bearing 24. The other end of the L-shaped block 25 is fixedly connected to the inner surface of the fixed cylinder 6. The number of driving wheels 10 is three, and friction blocks 26 are arranged on the surfaces of the three driving wheels 10. A perforating device 27 is arranged at the bottom of the setting tool 3, and a soluble bridge plug body 28 is arranged at the other end of the perforating device 27.

[0041] Further supplement; when the well diameter changes, the spring 11 pushes the protective cylinder 9 to displace radially, and the worm 13 slides axially through the chute 20, so that the driving wheel 10 always clings to the well wall. The spring 11 can provide a continuous pre-tightening force to the protective sleeve, making it cling to the inner wall of the wellbore, ensuring the stable operation of the device in the wellbore, and avoiding damaging the soluble bridge plug body 28 due to violent vibration or collision with the well wall. The clamping bolt 23 adopts an internal hexagonal countersunk head design, and the threaded part is coated with high-temperature anaerobic glue. The three-point clamping structure can generate a radial clamping force, ensuring that the setting tool 3 does not undergo axial displacement, and at the same time facilitating the temporary fixation of the setting tool 3 and the fixing ring 4, which is convenient for transporting the setting tool 3. The cooperation of the L-shaped block 25 and the ball bearing 24 realizes the axial positioning of the movable sleeve 14, ensuring the accuracy of the axial movement of the worm 13. The friction blocks 26 on the surface of the driving wheel 10 are arranged in a diamond grid pattern, and the friction blocks 26 protrude from the surface of the driving wheel 10, generating a controllable micro-cutting effect when contacting the well wall to ensure the traction force. The setting tool 3, the perforating device 27, and the soluble bridge plug body 28 (all of which are existing technologies in the field of shale oil exploitation and are well-known technologies to those skilled in the art, so they will not be elaborated in detail).

[0042] The working principle of the present invention is as follows: The hoisting device 1 lowers the assembled setting tool 3 and the soluble bridge plug body 28 into the target wellbore through the cable 2, fixes the setting tool 3 to the fixing ring 4 through the clamping bolt 23, and starts the servo motor 15 through an external controller (prior art). The output shaft of the servo motor 15 drives the driving cylinder 7 to rotate through the first gear 16 and the second gear 17, and the driving cylinder 7 drives the worm 13 to rotate through the first bevel gear 18 and the second bevel gear 19.

[0043] The rotational motion of the worm 13 is converted into the rotation of the driving wheel 10 through the worm gear 22. The three driving wheels 10 are always in close contact with the wellbore wall under the action of the spring 11. When encountering an enlarged section of the wellbore, the spring 11 pushes the protective cylinder 9 to extend outward to maintain the contact pressure of the driving wheel 10. When encountering a convex obstacle, the corresponding driving wheel 10 is compressed and retracted, and the worm 13 axially displaces along the chute 20 of the movable sleeve 14. At this time, the output torque of the other three groups of driving wheels 10 remains unchanged, ensuring that a static friction is generated between the propulsion friction block 26 and the wellbore wall to form a continuous propulsion force. Moreover, the three driving wheels 10 are driven by a single power source, enabling the three groups of driving wheels 10 to maintain strict synchronization, and its stability is higher compared with the traditional multi-motor solution. The self-locking characteristic of the worm gear 22 and the worm 13 is combined with the spring 11 adaptive system to ensure stable propulsion in an inclined well.

[0044] When reaching the target position: The soluble bridge plug body 28 is driven by the hydraulic system on the inner wall of the perforating device 27 to complete the setting device of the soluble bridge plug body 28. Then, the perforating device 27 is separated from the soluble bridge plug body 28, and the internal explosion device of the perforating device 27 is detonated to form a perforation channel. When retrieving, the driving wheel 10 and the hoisting device rotate in reverse together to achieve stable extraction.

[0045] Only some exemplary embodiments of the present invention have been described by way of illustration above. Undoubtedly, for those of ordinary skill in the art, without departing from the spirit and scope of the present invention, the described embodiments can be modified in various different ways. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A soluble bridge plug delivery device for staged fracturing of shale oil wells, comprising a hoisting device (1), characterized in that: The surface of the hoisting device (1) is wound with a cable (2), the other end of the cable (2) is fixedly connected with a setting tool (3), and a fixing ring (4) is sleeved on the surface of the setting tool (3); A driving assembly is arranged on the surface of the fixing ring (4). The driving assembly includes a sealing ring (5) fixedly connected to the bottom of the fixing ring (4), a fixing cylinder (6) fixedly connected to the top of the sealing ring (5), a driving cylinder (7) movably connected to the surface of the fixing ring (4) through a bearing seat, a through hole (8) opened on the surface of the fixing cylinder (6), a protective cylinder (9) arranged in the inner cavity of the through hole (8), and a driving wheel (10) movably connected to the inner wall of the protective cylinder (9) through a bearing seat; An adaptive assembly is arranged on the surface of the fixing cylinder (6). The adaptive assembly includes a spring (11) sleeved on the surface of the protective cylinder (9), a retaining ring (12) fixedly connected to the surface of the protective cylinder (9), a worm (13) movably connected to the inner wall of the protective cylinder (9) through a bearing seat, and a movable sleeve (14) sleeved on one end of the worm (13).

2. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: A servo motor (15) is fixedly connected to the surface of the fixing cylinder (6) through a mounting block. The output shaft of the servo motor (15) is fixedly connected with a first gear (16). A second gear (17) is meshed with one side of the first gear (16), and the center of the second gear (17) is fixedly connected to the surface of the driving cylinder (7).

3. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: A first bevel gear (18) is fixedly connected to the surface of the driving cylinder (7). A second bevel gear (19) is meshed with the surface of the first bevel gear (18), and the center of the second bevel gear (19) is fixedly connected to the surface of the movable sleeve (14).

4. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: A chute (20) is arranged in the inner cavity of the movable sleeve (14). A slider (21) is fixedly connected to the surface of the worm (13), and the slider (21) is slidably connected in the inner cavity of the chute (20).

5. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: A worm gear (22) is meshed with the surface of the worm (13), and the center of the worm gear (22) is fixedly connected to the surface of the driving wheel (10).

6. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: One end of the spring (11) is fixedly connected to the surface of the fixing cylinder (6), and the other end of the spring (11) is fixedly connected to one side of the retaining ring (12).

7. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: Threaded holes are opened on the surface of the fixing ring (4), and clamping bolts (23) are threadedly connected in the inner cavities of the threaded holes.

8. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: A ball bearing (24) is fixedly connected to the surface of the movable sleeve (14). The outer ring of the ball bearing (24) is fixedly connected with an L-shaped block (25), and the other end of the L-shaped block (25) is fixedly connected to the inner side surface of the fixing cylinder (6).

9. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, characterized in that: The number of the driving wheels (10) is three, and friction blocks (26) are arranged on the surfaces of the three driving wheels (10).

10. The soluble bridge plug delivery device for staged fracturing of shale oil wells according to claim 1, wherein: A perforating device (27) is arranged at the bottom of the setting tool (3), and a soluble bridge plug body (28) is arranged at the other end of the perforating device (27).

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