Downhole pipe electric cutting execution system

Abstract

The present invention discloses an electric cutting execution system for downhole tubulars, which can perform downhole electric cutting on the wellbore wall of oil casing of different sizes under high temperature and high pressure environment by applying a set of execution systems. The present invention includes a cutting head revolution system, a cutting head rotation system, and a cutting head deflection system. After passing through the planetary gears on the main transmission shaft, the auxiliary transmission shaft, and the blade main shaft, the motor finally applies the same torque to the blade, ensuring that the blade torque can achieve the same torque as the high-speed rotation torque; the electric cutting execution system can rotate by itself, achieving the purpose of circular cutting along the center line of the pipe; the deflection cutting system of the blade itself causes the cutting head to deflect. Under the joint cooperation of the high-speed cutting head system, the cutting head rotation system, and the cutting head deflection system, the downhole tubular cutting execution system can accurately control the cutting angle and position of the blade, achieving the purpose of cutting oil casing of different sizes with the same downhole cutting execution system.

Description

Technical Field

[0001] The invention relates to a downhole pipe string electric cutting execution system in the field of oil casing cutting tools used in well repair and completion operations. Background Art

[0002] Cutting technology is now widely used for cutting oil casing in well repair operations, cutting casing or riser pipe in offshore drilling and abandonment operations, and cutting stuck drill pipe. Existing pipe cutting methods mainly include hydraulic cutting and explosive cutting. Hydraulic cutting relies on circulating mud flow to control the cutting motion. During this process, the circulating pump pressure must be maintained stable. Large pressure fluctuations can easily cause the blade to break. Furthermore, hydraulic cutters are non-retractable, requiring strict adherence to operating procedures before and during the run. This technology is complex, requires significant human intervention, and has a relatively cumbersome operation procedure. Explosive cutting involves lowering a shaped charge cutting projectile above the stuck point and detonating it to sever the pipe string. Shaped charge cutting projects are explosive materials and pose a certain risk. Transportation and handling procedures for flammable, explosive, and hazardous materials require strict adherence to procedures. This makes it difficult to fully implement in regions such as Xinjiang and Qinghai. Furthermore, the outer end of the cut end protrudes outward, which can easily encounter resistance when lifted upward. Summary: Both traditional downhole pipe cutting technologies require positioning of the problematic pipe set by a locator before the above operations can be performed.

[0003] During downhole oil operations, the system tools are required to be able to output stably in a high-temperature, high-pressure environment. Therefore, the motor cutting execution system needs to solve the following major problems: (1) The structure of the system is limited by the diameter of the downhole tubing, and the structure is extremely compact, requiring a high degree of integration in design; (2) The displacement coefficient design of the sun gear and planetary gear of the transmission system must meet its output requirements; (3) In order to adapt to cutting tubing of different sizes and wall thicknesses, the rotary cutting head subsystem and the cutter head deflection system need to be optimized and matched in terms of software and hardware. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention provides a highly integrated downhole tubular electric cutting execution system that operates in a high temperature and high pressure environment and integrates sounding, positioning, anchoring and cutting.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] The downhole tubular electric cutting execution system includes a fastening shell and a cutting head rotation system, a cutting head revolution system, and a cutting head deflection system; the cutting head rotation system includes a main transmission shaft, a secondary transmission shaft, a blade main shaft and a blade, and a cutter head seat. The main transmission shaft, the secondary transmission shaft and the blade main shaft constitute a gear transmission in sequence. The blade is installed on the cutter head seat, and the cutter head seat is installed on the blade main shaft; the cutting head revolution system includes an input shaft, a reducer and a rotating seat, and a rotating shell. The input shaft is sleeved outside the main transmission shaft and is fixedly connected to the main transmission shaft. The input shaft is connected to the rotating seat and the rotating shell in sequence through the reducer. The secondary transmission shaft is installed under the rotating seat and can rotate relative to the rotating seat; the cutting head deflection system includes a transmission rod, a slider, a screw rod and a tool holder swivel seat. The slider and the screw rod constitute a spiral transmission. The rotation of the slider drives the screw rod to move eccentrically. The tool holder swivel seat is fixedly connected to the screw rod. The blade main shaft is installed on the tool holder swivel seat, and the secondary transmission shaft, the slider and the screw rod are installed in the rotating shell.

[0007] The above scheme further includes:

[0008] The slider is connected to a transmission rod, which is extended and retracted by a motor connected thereto. The slider is provided with a track that matches the spiral rod. The tool holder swivel seat is fixed in relative position to the spiral rod by a fixed key.

[0009] The reducer is a multi-stage planetary reducer; the input shaft is connected to the first-stage planetary reducer and then to the subsequent planetary reducers in sequence, and the last-stage planetary reducer is connected to the rotating seat through fastening screws.

[0010] The planetary reducer is a four-stage reducer including: a planetary carrier with three planetary gears, the rear end of the planetary carrier is connected to an identical planetary carrier with three planetary gears, the rear end of the planetary carrier is connected to a planetary carrier with three planetary gears of a speed reduction stage, the planetary carrier is further connected to a speed reduction planetary carrier with three planetary gears, and the speed reduction planetary carrier is connected to the rotating seat by fastening screws.

[0011] The reduction ratio of the planetary reducer is:-.

[0012] A reducer housing is sleeved on the outer side of the input shaft above the fastening housing, and a ball bearing is provided between the input shaft and the reducer housing.

[0013] A rotating head is also fixedly connected to the bottom of the rotating shell. A groove is provided in the rotating head. The blade spindle, the tool holder swivel seat and the blade are all installed in the groove of the rotating head.

[0014] A driving gear is arranged between the secondary transmission shaft and the blade main shaft.

[0015] The rotating seat is connected to the fastening housing through the centering bearing A and the centering bearing B; a centering bearing C is provided between the main transmission shaft and the rotating seat, and a centering bearing D is provided between the rotating seat and the auxiliary transmission shaft; a centering bearing is provided between the blade main shaft and the tool holder rotating seat.

[0016] The rotating shell fixes the axial position of the rotating seat, the rotating shell and the rotating head by fastening bolts.

[0017] The downhole tubular string cutting execution system of the present invention is divided into a cutting head revolution system, a cutting head rotation system, and a cutting head deflection system. The high-speed motor, after transmitting torque through the main drive shaft, auxiliary drive shaft, and planetary gears on the blade main shaft, ultimately applies the same torque to the blade. This ensures that the blade torque is equal to the high-speed rotation torque, achieving optimal torque transmission for the blade cutting the wellbore. The high-torque motor first applies torque to the input shaft through a coupling. After the rear end of the input shaft is reduced by a four-stage reducer, the torque is ultimately transmitted from high to low and applied to the main body of the electric cutting actuator, enabling the electric cutting actuator to rotate and achieve circular cutting along the centerline of the pipe. The blade's deflection cutting system is implemented by the interaction of a slider connected to the drive shaft. When the slider is subjected to a torque pull, the interaction between the slider surface and the spiral grooves on the spiral shaft causes the spiral shaft to produce a certain deflection angle, causing the cutting head to deflect. The motor speed is precisely controlled by a Hall effect detection system with numerous DC servo points on the front end. This is geometrically converted into the cutting head's deflection angle, achieving precise control of the cutting radius. With the coordinated effects of the high-speed cutting head system, the cutting head rotation system, and the cutting head deflection system, the downhole tubular cutting execution system can precisely control the cutting angle and position of the cutter head, achieving the goal of using the same downhole cutting execution system to cut oil casing of different sizes.

[0018] The electric cutting technology system of the present invention mainly solves the shortcomings of the two existing cutting technologies, such as complex operation, low cutting success rate, and low integration rate, and has the following advantages: (1) compact structure, reliable performance, and high cutting success rate; (2) accurate cutting depth and smooth incision; (3) it solves the technical problem of a set of electric cutting systems being able to cut the inner walls of oil casings of different sizes; (4) the construction process is simple; and (5) it can efficiently, quickly, and perfectly solve the problem of cutting downhole tubulars. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is the overall structural diagram of the downhole tubular electric cutting execution system of the present invention;

[0020] Figure 2 This is a distribution diagram of the cutter head rotation system of the downhole tubular electric cutting execution system of the present invention;

[0021] Figure 3 for Figure 2 Cross-sectional view along K1-K1 section;

[0022] Figure 4 for Figure 2 Cross-sectional view along K2-K2 section;

[0023] Figure 5 for Figure 2 Cross-sectional view along K3-K3 section;

[0024] Figure 6 for Figure 2 Cross-sectional view along K4-K4 section;

[0025] Figure 7 for Figure 2 Cross-sectional view along J-YJCD section;

[0026] Figure 8 for Figure 2 Cross-sectional view along G-EJCD section.

[0027] In the figure: 1. Coupling, 2. Key A, 3. Main drive shaft, 4. Ball bearing, 5. Input shaft, 6. Reducer housing, 7. Planet gear A, 8. Planet carrier A, 9. Planet gear B, 10. Planet carrier B, 11. Planet gear C, 12. Planet carrier C, 13. Speed ​​reduction planet gear, 14. Speed ​​reduction planet carrier, 15. Fastening screw, 16. Fastening housing, 17. Rotating seat, 18. Centering bearing A, 19. Centering bearing B, 20. Bolt, 21. Rotating housing, 22. Centering bearing C, 23. Centering bearing D, 24. Auxiliary drive shaft, 25. Slider, 26. Screw rod, 27. Key B, 28. Rotating head, 29. Tool holder swivel seat, 30. Centering bearing E, 31. Blade spindle, 32 Drive gear, 33. Centering bearing F, 34. Centering bearing G, 35. Centering bearing H, 36. Centering bearing I, 37. Cutter head seat, 38. Blade, 39. Skeleton oil seal, 40. Cutter cap, 41. Drive motor, 42. Transmission rod, 43. Connecting fixing key. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific implementation methods.

[0029] Example 1:

[0030] The downhole tubular electric cutting execution system includes a fastening shell 16 and a cutting head rotation system, a cutting head revolution system, and a cutting head deflection system; the cutting head rotation system includes a main transmission shaft 3, a secondary transmission shaft 24, a blade main shaft 31 and a blade 38, a cutter head seat 31, the main transmission shaft 3, the secondary transmission shaft 24 and the blade main shaft 31 constitute a gear transmission in sequence, the blade 38 is installed on the cutter head seat 31, and the cutter head seat 31 is installed on the blade main shaft 37; the cutting head revolution system includes an input shaft 5, a reducer and a rotating seat 17, a rotating shell 21, the input shaft 5 is sleeved outside the main transmission shaft 3 and is connected to the main transmission shaft 3 is fixedly connected, the input shaft 5 is sequentially connected to the rotating base 17 and the rotating housing 21 through a reducer, and the auxiliary transmission shaft 24 is installed below the rotating base 17 and can rotate relative to the rotating base 17; the cutting head deflection system includes a transmission rod 42, a slider 25, a screw rod 26 and a tool holder rotating base 29. The slider 25 and the screw rod 26 form a spiral transmission cooperation. The rotation of the slider 25 drives the screw rod 26 to move eccentrically. The tool holder rotating base 29 is fixedly connected to the screw rod 26. The blade spindle 31 is installed on the tool holder rotating base 29. The auxiliary transmission shaft 24, the slider 25 and the screw rod 26 are installed in the rotating housing 21.

[0031] Example 2:

[0032] Based on the above embodiment 1, further comprising:

[0033] The slider 25 is internally connected to a transmission rod, which is extended and retracted by a motor connected thereto. The slider 25 is externally provided with a track that matches the screw rod 26 , and the tool holder swivel seat 29 is fixed relative to the screw rod 26 by a fixed key.

[0034] The reducer is a multi-stage planetary reducer; the input shaft 5 is connected to the first-stage planetary reducer and then to the subsequent planetary reducers in sequence, and the last-stage planetary reducer is connected to the rotating seat 17 via a fastening screw 15.

[0035] The planetary reducer is a four-stage reducer including: a planet carrier 8 with three planetary gears 7, the rear end of the planet carrier 8 is connected to an identical planet carrier 10 with three planetary gears 9, the rear end of the planet carrier 10 is connected to a planet carrier 12 with three planetary gears 11 of a speed reduction stage, the planet carrier 12 is further connected to a speed reduction planet carrier 14 with three planetary gears 13, and the speed reduction planet carrier 14 is connected to a rotating seat 17 via fastening screws 15.

[0036] The reduction ratio of the planetary reducer is 1:100-200.

[0037] A reducer housing 6 is mounted on the outside of the input shaft 5 above the fastening housing 16 , and a ball bearing 4 is provided between the input shaft 5 and the reducer housing 6 .

[0038] A rotating head 28 is also fixedly connected to the bottom of the rotating shell 21 . A groove is provided in the rotating head 28 . The blade spindle 31 , the blade holder swivel seat 29 , and the blade 38 are all installed in the groove of the rotating head 28 .

[0039] A driving gear 32 is provided between the secondary transmission shaft 24 and the blade main shaft 31 .

[0040] The rotating seat 17 is connected to the fastening shell 16 through the centering bearing A18 and the centering bearing B19; a centering bearing C22 is provided between the main transmission shaft 3 and the rotating seat 17, and a centering bearing D23 is provided between the rotating seat 17 and the auxiliary transmission shaft 24; a centering bearing E30 is provided between the blade main shaft 31 and the tool holder swivel seat 29, a centering bearing H35 and a centering bearing I 36 are provided between the blade main shaft 31 and the cutter head seat 37, and a centering bearing F33 and a centering bearing G34 are provided between the auxiliary transmission shaft 24 and the tool holder swivel seat 29.

[0041] A blade cap 40 is provided between the blade spindle 31 and the blade 38, and a skeleton oil seal 39 is provided between the blade spindle 31 and the cutter head seat 37.

[0042] The rotating housing 21 fixes the axial position of the rotating base 17 , the rotating housing 21 , and the rotating head 28 by fastening bolts 20 .

[0043] Typical embodiment 3:

[0044] Refer to the attached Figure 1 The downhole tubular electric cutting execution system is mainly divided into three parts: high-speed cutting head revolution system, cutting head rotation system, and cutting head deflection system. Figure 2 This is the structural diagram of the cutter head rotation system, Figure 3 、 4 , 5 and 6 are the structural cross-sectional views of the sun gear and planetary gear of the four-stage planetary gear reducer. Figure 7 It shows the cross-sectional structure of the main transmission shaft and the auxiliary transmission shaft transmission mechanism. Figure 8 The transmission cross-section structure of the auxiliary transmission shaft and the blade main shaft is shown.

[0045] The power of the high-speed cutting head system comes from the torque transmitted by the drive motor 41 driving the coupling 1. The main transmission shaft 3 connected to the coupling 1 is fixed in the axial direction by the key 2 in the keyway. The gear at the end of the main transmission shaft 3 transmits the torque to the secondary transmission shaft 24 through the gear. The secondary transmission shaft 24 transmits the torque to the blade main shaft 31 with the same-level gear through the drive gear 32. The fixation between the two is axially fixed by the fixed key in the keyway. The blade main shaft 31 is connected to the cutter head seat 37 through a thread. The blade 38 is located on the cutter head seat 37. Through the transmission of multi-stage gears, the torque on the high-speed rotating coupling 1 is finally applied to the blade of the cutting knife 38, realizing the function of the high-speed cutting head to cut the inner wall of the pipe at high speed.

[0046] The cutting head's rotation system also draws power from coupling 1. The input shaft 5, connected to coupling 1, is axially secured by a key in a keyway. The torque from coupling 1 is applied to the input shaft 5. A ball bearing 4 is installed between the input shaft 5 and the reducer housing 6, preventing the reducer housing 6 from increasing with the torque on the input shaft 5. Gears at the rear end of input shaft 5 transmit the torque in stages to planetary carrier A8, which carries three planetary gears A7, achieving a uniform torque transmission. Planetary carrier A8 is connected to a similar planetary carrier B10, which carries three planetary gears B9. Planetary carrier B10 is connected to a reduction stage, planetary carrier C12, which carries three planetary gears C11, reducing the torque to 1:5. Planetary carrier C12 is further connected to a reduction stage, planetary carrier 14, which carries three reduction planetary gears 13. Compared to the initial torque transmission, this planetary gear system achieves a reduction ratio of 1:200. The deceleration planetary carrier 14 is connected to the rotating seat 17 via three fastening screws 15, thus achieving the deceleration transmission of the coupling 1 and applying torque to the rotating seat 17. The rotating seat 17 is connected to the fastening housing 16 via the stabilizing bearing A18 and the stabilizing bearing B19, ultimately forming a torque separation, so that the fastening housing 16 does not rotate with the transmission of the rotating seat 17. A stabilizing bearing C22 is provided between the main transmission shaft 3 and the rotating seat 17, and a stabilizing bearing D23 is provided between the rotating seat 17 and the secondary transmission shaft 24. Therefore, the torque of the rotating seat 17 does not act on the main transmission shaft 3 and the secondary transmission shaft 24, and therefore does not affect the torque transmission of the high-speed cutting head system. The five slender fastening screws located in the rotating shell 21 fix the axial position of the rotating seat 17, the rotating shell 21, and the rotating head 28, so that the torque of the three is the same, and the rotating shell 21 and the rotating head 28 rotate together with the rotating seat 17. This process ultimately achieves multi-stage speed reduction of the coupling 1 of the overall cutter head part, and finally transmits the torque to the cutting head part. While the blade 38 rotates at high speed for cutting, the cutting head itself will also revolve relative to the reducer housing 6 with the main transmission shaft 3 as the center, achieving the purpose of circular cutting along the center line of the tube.

[0047] The cutting head's deflection system is achieved through the movement of the track that cooperates between the slider 25 and the transmission rod 42. When the transmission rod 42 generates torque under the action of the drive motor 41, the slider 25 at the lowest end of the transmission rod 42, driven by the thread, exerts a leftward pulling force on the slider 25. The slider 25 at the lowest end of the transmission rod 42 is connected and fixed by a connecting key 43. Due to the spiral track that cooperates with the outer surface of the slider 25 and the spiral rod 26, the spiral rod 26 ultimately produces an axial deflection angle. The blade 38 is mounted on the cutter head holder 37, which is mounted on the blade spindle 31. The blade spindle 31 is mounted on the blade holder swivel 29, which is fixed relative to the spiral rod 26 by a fixing key. When the spiral rod 26 produces a radial deflection angle, the blade holder swivel 29 connected to it also produces a similar deflection angle. The torque that produces this deflection angle acts on the blade 38, causing the blade 38 to produce an axial deflection angle relative to its original position. This deflection process of the cutting head deflection system ultimately changes the radial extension of blade 38 out of reducer housing 6, enabling the cutting of various pipe wall thicknesses. To ensure downhole safety, the tool contains no nuts or slender fastening screws; the outer housing is threaded.

Claims

1. Downhole pipe electric cutting execution system, characterized by: The invention comprises a fastening housing (16) and a cutting head self-rotation system, a cutting head revolution system, and a cutting head deflection system; the cutting head self-rotation system comprises a main transmission shaft (3), a secondary transmission shaft (24), a blade spindle (31), a blade (38), and a cutter head seat (37); the main transmission shaft (3), the secondary transmission shaft (24), and the blade spindle (31) sequentially form a gear transmission; the blade (38) is mounted on the cutter head seat (37), and the cutter head seat (37) is mounted on the blade spindle (31); the cutting head revolution system comprises The invention comprises an input shaft (5), a reducer and a rotating seat (17), and a rotating shell (21), wherein the input shaft (5) is sleeved outside the main transmission shaft (3) and is fixedly connected to the main transmission shaft (3), the input shaft (5) is connected to the rotating seat (17) and the rotating shell (21) in sequence through the reducer, and the auxiliary transmission shaft (24) is installed below the rotating seat (17) and can rotate relative to the rotating seat (17); the cutting head deflection system comprises a transmission rod (42), a slider (25), a spiral rod (26) and a knife holder rotating seat (2 9), the slider (25) and the screw rod (26) form a spiral transmission cooperation, the rotation of the slider (25) drives the screw rod (26) to move eccentrically, the tool holder swivel seat (29) is fixedly connected to the screw rod (26), the blade spindle (31) is installed on the tool holder swivel seat (29), the auxiliary transmission shaft (24), the slider (25) and the screw rod (26) are installed in the rotating shell (21); the rotating shell (21) is also fixedly connected to a rotating head (28), and a groove is provided in the rotating head (28), and the tool holder is fixedly connected to the rotating head (28). The wing spindle (31), the knife holder swivel seat (29), and the blade (38) are all installed in the groove of the rotating head (28); the rotating seat (17) is connected to the fastening housing (16) through the centering bearing A (18) and the centering bearing B (19); a centering bearing C (22) is provided between the main transmission shaft (3) and the rotating seat (17), and a centering bearing D (23) is provided between the rotating seat (17) and the auxiliary transmission shaft (24); and a centering bearing is provided between the blade wing spindle (31) and the knife holder swivel seat (29).

2. The downhole tubular electric cutting execution system according to claim 1, characterized in that: The slider (25) is internally connected to a transmission rod, which is extended and retracted by a motor connected thereto. The slider (25) is provided with a track matched with the spiral rod (26). The knife holder swivel seat (29) is fixed relative to the spiral rod (26) by a fixing key.

3. The downhole pipe electric cutting execution system according to claim 1 or 2, characterized in that The reducer is a multi-stage planetary reducer; the input shaft (5) is connected to the first-stage planetary reducer and then sequentially connected to the subsequent planetary reducers, and the final-stage planetary reducer is connected to the rotating seat (17) via a fastening screw (15).

4. The downhole pipe electric cutting execution system according to claim 3, characterized in that The planetary reducer is a four-stage reducer comprising: a planet carrier A (8) with three planetary gears A (7); the rear end of the planet carrier A (8) is connected to an identical planet carrier B (10) with three planetary gears B (9); the rear end of the planet carrier B (10) is connected to a planet carrier C (12) with three planetary gears C (11) of a speed reduction stage; the planet carrier C (12) is connected to a speed reduction planet carrier (14) with three speed reduction planetary gears (13); the speed reduction planet carrier (14) is connected to a rotating seat (17) via a fastening screw (15).

5. The downhole tubular electric cutting execution system according to claim 4, characterized in that: The reduction ratio of the planetary reducer is 1:100-200.

6. The downhole tubular electric cutting execution system according to claim 1 or 2, characterized in that: A reducer housing (6) is also sleeved on the outside of the input shaft (5) above the fastening housing (16), and a ball bearing (4) is provided between the input shaft (5) and the reducer housing (6).

7. The downhole tubular electric cutting execution system according to claim 1 or 2, characterized in that: A driving gear (32) is arranged between the secondary transmission shaft (24) and the blade main shaft (31).

8. The downhole tubular electric cutting execution system according to claim 1 or 2, characterized in that: The rotating shell (21) fixes the axial position of the rotating seat (17), the rotating shell (21), and the rotating head (28) by means of fastening bolts (20).

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