Anti-impact borehole enlarging device

Abstract

The anti-impact borehole expanding device comprises a pipe body, a cutter wing capable of sliding up and down is arranged on the side wall of the pipe body, a hydraulic cylinder body is arranged below the cutter wing, and a hydraulic cavity is formed in the inner side of the hydraulic cylinder body; the central pipe is fixedly arranged in the pipe body; the second fixing seat is located below the hydraulic cylinder body, a first passing opening is formed in the second fixing seat, the first passing opening is located in the hydraulic cavity, and the communication state of the central pipe and the hydraulic cavity is adjusted by controlling the first passing opening to be opened and closed; when the central pipe and the hydraulic cavity are in a communicating state, drilling fluid in the central pipe can enter the hydraulic cavity and push the hydraulic cylinder body to move upwards so as to control the blades to move upwards and move towards the outer side of the pipe body at the same time, and the blades are unfolded. Compared with the prior art, the hole expanding device has better hole expanding stability, the vibration condition of a downhole drilling tool during hole expanding operation can be effectively improved, the hole diameter expanding rate is increased, and the well cementation quality and the operation safety are improved.

Description

Technical Field

[0001] This invention relates to the field of petroleum and geological drilling technology, and more particularly to an anti-impact wellbore enlargement device. Background Technology

[0002] Deep onshore formations are a crucial energy reserve, with 39% of the remaining oil and 57% of the remaining natural gas located there. Deep and ultra-deep oil and gas resources have become key strategic areas for oil and gas development. However, deep and ultra-deep wells present challenges such as complex well depth structures, small casing clearances, and difficulties in ensuring cementing quality. Reaming while drilling can effectively increase the casing annulus clearance and improve cementing quality. Furthermore, in some areas (such as the Tarim Basin), where creep in salt-gypsum layers causes stuck pipe and reduced diameter, reaming while drilling can enlarge the wellbore in these layers, prevent stuck pipe, and increase the cement sheath thickness, enhancing the casing-cement sheath system's resistance to formation creep. However, current reaming operations commonly suffer from severe vibrations in the downhole drilling assembly, leading to tool breakage, disconnection, and cutter wing damage, seriously hindering the widespread use of reaming tools.

[0003] Therefore, based on years of experience and practice in related industries, the inventor proposes an anti-impact wellbore enlargement device to overcome the shortcomings of existing technologies. Summary of the Invention

[0004] The purpose of this invention is to provide an anti-impact wellbore enlargement device for use in oil exploration drilling operations during borehole enlargement. It effectively improves the vibration condition of downhole drilling tools during enlargement operations, increases the wellbore enlargement rate, prevents necking and stuck pipe, improves the clearance between the casing and the wellbore annulus, and improves cementing quality and operational safety.

[0005] The objective of this invention can be achieved through the following methods:

[0006] This invention provides an anti-impact wellbore enlargement device, the anti-impact wellbore enlargement device comprising:

[0007] The tube body has multiple blade grooves formed on its side wall along its length, and the multiple blade grooves are distributed at intervals along the circumference of the tube body;

[0008] A central tube is fixedly installed inside the tube body and is used to supply drilling fluid.

[0009] Multiple blades, wherein the multiple blades are slidably disposed within corresponding blade grooves;

[0010] A sleeve is disposed inside the tube, the sleeve is located above the blade and sleeved on the outside of the central tube, the sleeve is connected to the tube through a first fixing seat, and a spring is disposed inside the sleeve and on the outer periphery of the central tube, the two ends of the spring abutting against the top inner wall of the sleeve and the top of the blade respectively.

[0011] A hydraulic cylinder body is disposed inside the tube. The hydraulic cylinder body is located below the blade and is slidably sleeved on the outside of the central tube. A hydraulic chamber is formed on the inner side of the hydraulic cylinder body.

[0012] The second fixing seat is disposed inside the pipe body and located below the hydraulic cylinder body. The second fixing seat is connected to the bottom of the central pipe and has at least one first through port. The second fixing seat extends into the hydraulic cavity at the location of the first through port. By controlling the opening and closing of the first through port, the communication state between the central pipe and the hydraulic cavity is adjusted. When the central pipe and the hydraulic cavity are in a communication state, the drilling fluid can push the hydraulic cylinder body upward to control the multiple cutter wings to move upward and outward to the outside of the pipe body.

[0013] In a preferred embodiment of the present invention, the anti-impact wellbore enlargement device further includes an activation sleeve and a closing sleeve, wherein the activation sleeve and the closing sleeve are respectively fixed in the second fixing seat by a first shear pin and a second shear pin, and the activation sleeve is located below the closing sleeve.

[0014] The anti-impact wellbore enlargement device has an initial state, an activated state, and a closed state.

[0015] When the anti-impact wellbore enlargement device is in its initial state, the activation sleeve blocks the first passage, and the drilling fluid can flow through the inside of the first fixed seat, the central tube, and the second fixed seat.

[0016] When the anti-impact wellbore enlargement device is activated, an activation ball is inserted into the activation sleeve to block the flow of drilling fluid. The pressure in the central tube cuts off the first shear pin, the activation sleeve falls, and the central tube communicates with the hydraulic chamber through the first through port. The drilling fluid enters the hydraulic chamber to push the hydraulic cylinder upward. The hydraulic cylinder pushes the cutter blade upward along the cutter blade groove while moving outward to control the deployment of multiple cutter blades.

[0017] When the anti-impact wellbore enlargement device is in the closed state, a closing ball is inserted into the closing sleeve to block the drilling fluid from flowing into the hydraulic chamber. The pressure in the central tube cuts off the second shear pin, and the closing sleeve falls to the position to block the first passage. The spring pushes the cutter blade down along the cutter blade groove and moves towards the inside of the pipe body to control the multiple cutter blades to retract into the pipe body.

[0018] In a preferred embodiment of the present invention, the anti-impact wellbore enlargement device further includes an upper connector and a first anti-reverse ring. The upper connector is connected to the top end of the pipe body and is used to connect to the upper drilling tool. The first anti-reverse ring is disposed in the pipe body and pressed between the upper connector and the first fixed seat. The outer wall of the first anti-reverse ring is sealed to the inner wall of the pipe body.

[0019] In a preferred embodiment of the present invention, the blade slide groove is an elongated slot hole opened along the extension direction of the tube body, and the two opposite inner walls of the blade slide groove each have a guide groove that gradually slopes upward from the inside to the outside.

[0020] The blade has guide ribs on its two opposite outer walls that cooperate with the guide groove. The blade is located in the blade groove, and the guide ribs are slidably embedded in the corresponding guide grooves to guide the blade to move upward along the blade groove while moving outward to the outside of the tube.

[0021] In a preferred embodiment of the present invention, the first fixing seat is cylindrical, the outer wall of the first fixing seat is sealed to the inner wall of the tube, the top of the central tube extends into the inner side of the first fixing seat, and the outer wall of the central tube is sealed to the inner wall of the first fixing seat.

[0022] In a preferred embodiment of the present invention, the sleeve is located below the first fixed seat, and the top of the sleeve is connected to the bottom of the first fixed seat. The spring is sleeved on the outer periphery of the central tube, and the top of the spring abuts against the top inner wall of the sleeve.

[0023] A first retaining ring is provided above the blade wing, which can slide along the blade wing groove, and the bottom of the spring abuts against the top of the first retaining ring.

[0024] In a preferred embodiment of the present invention, a plurality of first support arms are provided on the outer wall of the first retaining ring, extending in a direction away from the center of the first retaining ring. The plurality of first support arms are distributed at intervals along the circumference of the first retaining ring and correspond one-to-one with the plurality of blade wing grooves. The plurality of first support arms are slidably embedded in the corresponding blade wing groove.

[0025] In a preferred embodiment of the present invention, the bottom of the first support arm has a first inclined surface at a first preset angle to the horizontal direction, and the top of the blade has a second inclined surface in the opposite direction to the first inclined surface, and the first inclined surface abuts against the second inclined surface.

[0026] In a preferred embodiment of the present invention, a second retaining ring is provided below the blade wing, which can slide along the blade wing groove, and the second retaining ring is connected to the top of the second fixing seat;

[0027] The outer wall of the second retaining ring is provided with a plurality of second support arms extending away from the center of the second retaining ring. The plurality of second support arms are distributed at intervals along the circumference of the second retaining ring and correspond one-to-one with the plurality of blade wing grooves. The plurality of second support arms are slidably embedded in the corresponding blade wing grooves.

[0028] The spring presses the first retaining ring, the blade, and the second retaining ring together.

[0029] In a preferred embodiment of the present invention, the top of the second support arm has a third inclined surface that forms a second preset angle with the horizontal direction, and the bottom of the blade has a fourth inclined surface that is in the opposite direction to the third inclined surface, and the third inclined surface abuts against the fourth inclined surface.

[0030] In a preferred embodiment of the present invention, an annular first shoulder is formed on the lower inner wall of the activation sleeve, which gradually narrows from top to bottom. The diameter of the activation ball is larger than the inner diameter of at least a portion of the first shoulder, so that the activated ball can be seated on the first shoulder when inserted.

[0031] In a preferred embodiment of the present invention, an annular second shoulder is formed on the lower inner wall of the closing sleeve, which gradually narrows from top to bottom, and the diameter of the closing ball is larger than the inner diameter of at least a portion of the second shoulder, so that the inserted closing ball can sit and seal on the second shoulder.

[0032] The diameter of the activation ball is smaller than the inner diameter of the second shoulder, so that the activation ball can pass through the closing sleeve and fall into the activation sleeve.

[0033] In a preferred embodiment of the present invention, the second fixing seat is a cylindrical shape arranged along the extension direction of the pipe body. A cavity is formed inside the second fixing seat. The first through port is located above the cavity. A second through port is arranged on the second fixing seat and below the cavity. The cavity is connected to the pipe body through the second through port and the annular space between the second fixing seat and the pipe body. A flow channel is opened on the pipe wall of the pipe body at a position opposite to the second fixing seat. The drilling fluid in the cavity can be discharged outward in sequence through the second through port and the flow channel.

[0034] The flow channel is equipped with a water nozzle to control its on / off state.

[0035] In a preferred embodiment of the present invention, the anti-impact wellbore enlargement device further includes a connecting cylinder disposed within the pipe body, the top of the connecting cylinder being connected to the bottom of the central pipe, and the bottom of the connecting cylinder being connected to the top of the second fixing seat.

[0036] In a preferred embodiment of the present invention, the anti-impact wellbore enlargement device further includes a lower connector and a second anti-reverse ring. The lower connector is connected to the bottom end of the pipe body and is used to connect to the lower drilling tool. The second anti-reverse ring is disposed in the pipe body and pressed between the lower connector and the second fixed seat. The outer wall of the second anti-reverse ring is sealed to the inner wall of the pipe body.

[0037] As described above, the features and advantages of the anti-impact wellbore enlargement device of the present invention are as follows: By controlling the on / off state of the first passage located between the central pipe and the hydraulic chamber of the hydraulic cylinder, the drilling fluid in the central pipe is controlled to enter the hydraulic chamber. When the central pipe and the hydraulic chamber are disconnected (i.e., the first passage is closed), the drilling fluid can flow normally through the central pipe into the well; when the central pipe and the hydraulic chamber are connected (i.e., the first passage is open), the lower part of the central pipe is blocked, and the continuously flowing drilling fluid will enter the hydraulic chamber through the first passage, thereby pushing the hydraulic cylinder upward, and the upward movement of the hydraulic cylinder will push the wellbore above it. Guided by the wing groove, the cutter wings move upwards and outwards from the casing, thus unfolding the wings. This unfolded wings allow for wellbore enlargement operations. The wellbore enlargement device of this invention can be lowered into a preset position within the wellbore along with the drill string, enabling simultaneous reaming operations during exploratory drilling, increasing the wellbore enlargement rate, preventing necking and stuck pipe, and improving the clearance between the casing and the annulus. Because the wing unfolding is hydraulically driven, it offers better stability compared to other electric or mechanical drives, effectively reducing downhole drill string vibration during reaming operations, improving cementing quality and operational safety. Attached Figure Description

[0038] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0039] in:

[0040] Figure 1 This is a schematic diagram of the anti-impact wellbore enlargement device of the present invention in its initial state;

[0041] Figure 2 This is a schematic diagram of the anti-impact wellbore enlargement device of the present invention in the activated state;

[0042] Figure 3 This is a schematic diagram of the anti-impact wellbore enlargement device of the present invention in the closed state;

[0043] Figure 4 This is a schematic diagram of the pipe body in the anti-impact wellbore enlargement device of the present invention;

[0044] Figure 5 This is a schematic diagram of the structure of the first anti-reverse ring in the anti-impact wellbore enlargement device of the present invention;

[0045] Figure 6 This is a schematic diagram of the structure of the first fixed seat in the anti-impact wellbore enlargement device of the present invention;

[0046] Figure 7 This is one of the perspective views of the first retaining ring in the anti-impact wellbore enlargement device of the present invention;

[0047] Figure 8 This is a second perspective view of the first retaining ring in the anti-impact wellbore enlargement device of the present invention;

[0048] Figure 9 This is a perspective view of the cutter blade in the anti-impact wellbore enlargement device of the present invention;

[0049] Figure 10 This is a front view of the cutter blade in the anti-impact wellbore enlargement device of the present invention;

[0050] Figure 11 This is a perspective view of the guide component in the anti-impact wellbore enlargement device of the present invention;

[0051] Figure 12 This is one of the perspective views of the second retaining ring in the anti-impact wellbore enlargement device of the present invention;

[0052] Figure 13 This is a second perspective view of the second retaining ring in the anti-impact wellbore enlargement device of the present invention;

[0053] Figure 14 This is a schematic diagram of the hydraulic cylinder body in the anti-impact wellbore enlargement device of the present invention;

[0054] Figure 15 This is a schematic diagram of the closed sliding sleeve in the anti-impact wellbore enlargement device of the present invention;

[0055] Figure 16 This is a schematic diagram of the structure of the second fixing seat in the anti-impact wellbore enlargement device of the present invention;

[0056] Figure 17 This is a schematic cross-sectional view of the location of the second through-hole on the second fixed seat in the anti-impact wellbore enlargement device of the present invention;

[0057] Figure 18This is a schematic diagram of the structure of the second anti-reverse ring in the anti-impact wellbore enlargement device of the present invention;

[0058] Figure 19 This is a schematic diagram of the activated sliding sleeve in the anti-impact wellbore enlargement device of the present invention.

[0059] The reference numerals in the accompanying drawings of this invention are:

[0060] 1. Upper connector; 2. Pipe body;

[0061] 201. Blade slide groove; 2011. Guide groove;

[0062] 202. Flow channel; 203. Eighth sealing groove;

[0063] 3. First anti-reverse ring; 301. Fourth sealing groove;

[0064] 302. First tooling hole; 4. First fixing seat;

[0065] 401. Sixth sealing groove; 402. Seventh sealing groove;

[0066] 403. First tooling groove; 5. Central tube;

[0067] 6. Sleeve; 7. Spring;

[0068] 8. Baffle; 9. Fixing bolts;

[0069] 10. First retaining ring; 1001. First support arm;

[0070] 1002, First groove; 1003, First threaded hole;

[0071] 1004. First inclined plane; 11. Blade wing;

[0072] 1101. Guide rib; 1102. Cutting teeth;

[0073] 1103. Maintain diameter tooth; 1104. Reverse expansion tooth;

[0074] 1105. Second inclined plane; 1106. Fourth inclined plane;

[0075] 12. Second retaining ring; 1201. Second support arm;

[0076] 1202, Third inclined plane; 1203, Second groove;

[0077] 1204. Third threaded hole; 13. Guide component;

[0078] 1301. Concave part; 1302. Flat key;

[0079] 1303, Second threaded hole; 1304, Protrusion;

[0080] 14. Water tap; 15. Connecting tube;

[0081] 16. Hydraulic cylinder body; 1601. Ninth sealing groove;

[0082] 1602, Card slot; 1603, Second tooling slot;

[0083] 17. Close the slide; 1701. Second shoulder;

[0084] 1702. Second connecting groove; 1703. Second sealing groove;

[0085] 18. Second fixing seat; 1801. First passageway;

[0086] 1802. Second passageway; 1803. Third sealing groove;

[0087] 1804, Boss; 1805, First connecting hole;

[0088] 1806. Second connecting hole; 1807. Chamber;

[0089] 19. Activate the sliding sleeve; 1901. First sealing groove;

[0090] 1902, First shoulder; 1903, First connecting groove;

[0091] 20. Second anti-reverse ring; 2001. Fifth sealing groove;

[0092] 2002, Second tooling hole; 21, Lower connector;

[0093] 22. Activate the ball; 23. Deactivate the ball;

[0094] 24. Hydraulic chamber. Detailed Implementation

[0095] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0096] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intervening element. Furthermore, the directional terms such as "upper," "lower," "top," "bottom," "inner," and "outer" used in this invention are all used to indicate direction. Figures 1 to 3The directions such as "up", "down", "top", "bottom", "inner", and "outer" are used as a reference to clearly and explicitly define the connection and positional relationships between the components, but do not limit the actual direction. This is explained here.

[0097] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0098] This invention provides an anti-impact wellbore enlargement device for use during drilling reaming in oil exploration operations. It can increase the wellbore enlargement rate, prevent necking and stuck pipe, improve the clearance between the casing and the annulus, effectively reduce the vibration of downhole drilling tools during reaming operations, and improve cementing quality and operational safety. Furthermore, this anti-impact wellbore enlargement device offers advantages such as simple operation, safety and reliability, and reduced tripping time during reaming operations, making it suitable for drilling fields such as petroleum and geology.

[0099] like Figures 1 to 19As shown, the present invention provides an anti-impact wellbore enlargement device, which includes: a pipe body 2, which is arranged vertically, and a plurality of blade grooves 201 are formed on the side wall of the pipe body 2 along its length, the plurality of blade grooves 201 being spaced apart and evenly distributed along the circumference of the pipe body 2; a central pipe 5, which is fixedly arranged inside the pipe body 2 and is coaxially arranged with the pipe body 2, and is used for drilling fluid to pass through; a plurality of blades 11, the plurality of blades 11 corresponding one-to-one with the plurality of blade grooves 201, the plurality of blades 11 being slidably arranged in the corresponding blade grooves 201; a sleeve 6, which is arranged inside the pipe body 2, located above each blade 11 and sleeved on the outside of the central pipe 5, the sleeve 6 being connected to the pipe body 2 through a cylindrical first fixing seat 4, and a spring 7 being arranged inside the sleeve 6 and on the outer periphery of the central pipe 5, the two ends of the spring 7 being respectively connected to the sleeve 6. The top inner wall of the central tube 5 abuts against the top of the blade 11; a hydraulic cylinder 16 is disposed inside the tube 2, located below the blade 11 and slidably fitted onto the outside of the central tube 5, with a hydraulic cavity 24 formed on the inner side of the hydraulic cylinder 16; a cylindrical second fixing seat 18 is disposed inside the tube 2 and located below the hydraulic cylinder 16, connected to the bottom of the central tube 5, and having at least one first through port 1801, the second fixing seat 18 extends into the hydraulic cavity 24 at the location of the first through port 1801, and the connection between the central tube 5 and the hydraulic cavity 24 is adjusted by controlling the opening and closing of the first through port 1801; when the central tube 5 and the hydraulic cavity 24 are in a connected state, the drilling fluid can push the hydraulic cylinder 16 upward to control the upward movement of multiple blades 11 while moving them to the outside of the tube 2.

[0100] In this invention, the drilling fluid in the central pipe 5 is controlled to enter the hydraulic chamber 24 by controlling the opening and closing state of the first passage 1801 located between the central pipe 5 and the hydraulic chamber 24 of the hydraulic cylinder 16. When the central pipe 5 and the hydraulic chamber 24 are disconnected (i.e., the first passage 1801 is closed), the drilling fluid can flow normally through the central pipe 5 into the well. When the central pipe 5 and the hydraulic chamber 24 are connected (i.e., the first passage 1801 is open), the lower part of the central pipe 5 is blocked (by the activation ball 22 described below), and the drilling fluid continuously flowing into the central pipe 5 will enter the hydraulic chamber 24 through the first passage 1801, thereby pushing the hydraulic cylinder 16 upward. The upward movement of the hydraulic cylinder 16... The device pushes multiple blades 11 located above it. Under the guidance of the blade groove 201, the multiple blades 11 move upward and outward to the outside of the pipe body 2, thereby unfolding the blades 11. The unfolded blades 11 can be used for wellbore enlargement operations. The wellbore enlargement device of the present invention can be lowered into the wellbore to a preset position with the drill string. It can carry out wellbore enlargement operations while conducting exploration drilling, improve the wellbore enlargement rate, prevent necking and stuck drill, and improve the clearance between the casing and the well wall annulus. Since the unfolding of the blades 11 is driven by hydraulically, it has better stability than other electric or mechanical drive methods. It can effectively improve the vibration of the downhole drill string during wellbore enlargement operations, improve cementing quality and operational safety.

[0101] In an optional embodiment of the present invention, such as Figures 1 to 3 As shown, the anti-impact wellbore enlargement device also includes an activation sleeve 19 and a closing sleeve 17. The activation sleeve 19 is fixed to the second fixing base 18 by a first shear pin, and the closing sleeve 17 is fixed to the second fixing base 18 by a second shear pin, with the activation sleeve 19 located below the closing sleeve 17. The anti-impact wellbore enlargement device of the present invention has an initial state, an activated state, and a closed state. When the anti-impact wellbore enlargement device is in the initial state, such as... Figure 1 As shown, the fixed position of the activated sliding sleeve 19 precisely seals the first passage 1801, allowing drilling fluid to flow into the well through the inner sides of the first fixed seat 4, the central pipe 5, and the second fixed seat 18; when the anti-impact wellbore enlargement device is activated, as... Figure 2As shown, an activation ball 22 (which can be deployed from the wellhead) is inserted into the activation sleeve 19. The activation ball 22 blocks the flow of drilling fluid into the well, creating a pressure-blocking zone above it. As drilling fluid continues to flow in, the pressure above the activation ball 22 increases until the pressure in the central tube 5 cuts the first shear pin, causing the activation sleeve 19 to fall and the central tube 5 to connect to the hydraulic chamber 24 through the first through-port 1801. At this time, the drilling fluid in the central tube 5 can enter the hydraulic chamber 24 through the first through-port 1801 to push the hydraulic cylinder 16 upward. The hydraulic cylinder 16 pushes the cutter wings 11 upward along the cutter wing groove 201 while moving them outward from the tube body 2 to control the deployment of multiple cutter wings 11. When the anti-impact wellbore enlargement device is in the closed state, as... Figure 3 As shown, a closing ball 23 (which can be deployed from the wellhead) is inserted into the closing sleeve 17. Since the closing sleeve 17 is located above the first access port 1801, the closing ball 23 can block the drilling fluid from flowing into the hydraulic chamber 24. A pressure-stabilized area is formed above the closing ball 23. The pressure in the central tube 5 cuts off the second shear pin, and the closing sleeve 17 falls to the position to seal the first access port 1801. The closing sleeve 17 plays the same role as the original activating sleeve 19, that is, to seal the first access port 1801. Under the action of the spring force of the spring 7, the cutter wing 11 moves down along the cutter wing groove 201 and moves towards the inside of the tube body 2, and retracts into the tube body 2.

[0102] In an optional embodiment of the present invention, such as Figure 19 As shown, the activation sleeve 19 is a vertically arranged cylindrical shape. A first annular shoulder 1902 that gradually narrows from top to bottom is formed on the lower inner wall of the activation sleeve 19. The diameter of the activation ball 22 is larger than the inner diameter of at least part of the first shoulder 1902, so that the activated ball 22 can be seated on the first shoulder 1902 when it is inserted.

[0103] Furthermore, such as Figure 19 As shown, a plurality of annular first sealing grooves 1901 are provided circumferentially on the outer wall of the activation sleeve 19. A sealing ring can be embedded in the first sealing groove 1901 to ensure a sealed connection between the activation sleeve 19 and the inner wall of the second fixed seat 18. In addition, a first connecting groove 1903 is also provided on the outer wall of the activation sleeve 19. A first shear pin can be set at the location of the first connecting groove 1903 to connect the activation sleeve 19 and the second fixed seat 18.

[0104] In an optional embodiment of the present invention, such as Figure 15As shown, the closing sleeve 17 is a vertically arranged cylindrical shape. A gradually tapering annular second shoulder 1701 is formed on the lower inner wall of the closing sleeve 17. The diameter of the closing ball 23 is larger than the inner diameter of at least a portion of the second shoulder 1701, so that the inserted closing ball 23 can be seated within the second shoulder 1701. Additionally, it is necessary to ensure that the diameter of the activation ball 22 is smaller than the inner diameter of the second shoulder 1701, so that when the activation ball 22 is inserted, it can pass through the closing sleeve 17 and fall into the activation sleeve 19.

[0105] Furthermore, such as Figure 15 As shown, a plurality of annular second sealing grooves 1703 are provided circumferentially on the outer wall of the closing slide sleeve 17. A sealing ring can be embedded in the second sealing groove 1703 to ensure a sealed connection between the closing slide sleeve 17 and the inner wall of the second fixed seat 18. In addition, a second connecting groove 1702 is also provided on the outer wall of the closing slide sleeve 17. A second shear pin can be installed at the location of the second connecting groove 1702 to connect the closing slide sleeve 17 and the second fixed seat 18.

[0106] In an optional embodiment of the present invention, such as Figures 1 to 4 , Figure 16 , Figure 17 As shown, the second fixing seat 18 is a cylindrical shape arranged along the extension direction of the pipe body 2. The second fixing seat 18 is divided into an upper section, a middle section and a lower section from top to bottom. The diameter of the middle section is larger than the diameter of the upper section and the lower section, and a chamber 1807 is formed inside the middle section. The first through port 1801 is located above the chamber 1807 (the first through port 1801 is located in the upper section). A second through port 1802 is arranged on the second fixing seat 18 and below the chamber 1807. The chamber 1807 is connected to the annulus between the second fixing seat 18 and the pipe body 2 through the second through port 1802 and the second fixing seat 18. A flow channel 202 is opened on the pipe wall of the pipe body 2 at a position opposite to the second fixing seat 18. The drilling fluid in the chamber 1807 can be discharged outward through the second through port 1802 and the flow channel 202 in sequence. When the anti-impact wellbore enlargement device is in the closed state, the drilling fluid in the central pipe 5 can no longer enter the well through the original path due to the sealing of the closing ball 23. At this time, the drilling fluid can be discharged through the second outlet 1802 and the flow channel 202 in sequence to achieve normal circulation of the drilling fluid.

[0107] Furthermore, such as Figures 1 to 4 As shown, a water nozzle 14 is provided on the flow channel 202 to control its opening and closing. When the anti-impact wellbore enlargement device is in the closed state, the water nozzle 14 can be controlled to close; and when the anti-impact wellbore enlargement device is in the closed state, the water nozzle 14 can be controlled to open so that the drilling fluid can pass through smoothly.

[0108] Furthermore, there are multiple first access ports 1801 and multiple second access ports 1802, which are spaced apart and evenly arranged along the circumference of the second fixing seat 18. The specific number and spacing of the first access ports 1801 and the second access ports 1802 can be set according to the actual situation and are not specifically limited here.

[0109] Furthermore, such as Figure 2 , Figure 3 , Figure 16 As shown, the bottom inner wall of the lower section of the second fixed seat 18 is provided with an annular boss 1804. The boss 1804 serves to support the activation sleeve 19. When the first shear pin is sheared and the activation sleeve 19 falls, it will abut against the boss 1804 and limit the movement, preventing the activation sleeve 19 from falling into the well.

[0110] Furthermore, such as Figure 2 , Figure 3 , Figure 16 As shown, a plurality of first connecting holes 1805 are spaced apart along the circumference of the upper section of the second fixed base 18. Second shear pins can be connected to the first connecting holes 1805 to close the connection between the sliding sleeve 17 and the second fixed base 18. A plurality of second connecting holes 1806 are spaced apart along the circumference of the lower section of the second fixed base 18. First shear pins can be connected to the second connecting holes 1806 to activate the connection between the sliding sleeve 19 and the second fixed base 18. Additionally, a plurality of annular third sealing grooves 1803 are provided along the circumference of the outer wall of the second fixed base 18. Sealing rings can be embedded in the third sealing grooves 1803 to ensure the sealing of the installation position of the second fixed base 18.

[0111] In an optional embodiment of the present invention, such as Figures 1 to 5 As shown, the anti-impact wellbore enlargement device also includes a cylindrical upper connector 1 and a first anti-reverse ring 3. The upper connector 1 is threadedly connected to the top end of the pipe body 2. The upper connector 1 is used to connect to the upper drilling tool, thereby allowing the anti-impact wellbore enlargement device of the present invention to be lowered to a preset position in the well. The first anti-reverse ring 3 is disposed inside the pipe body 2 and pressed between the upper connector 1 and the first fixing seat 4. The outer wall of the first anti-reverse ring 3 is sealed to the inner wall of the pipe body 2. By setting the first anti-reverse ring 3, the threaded connection between the first fixing seat 4 and the pipe body 2 is prevented from back-threading, increasing the stability and diameter retention capacity of the tool.

[0112] Furthermore, such as Figure 5As shown, a plurality of annular fourth sealing grooves 301 are provided circumferentially on the outer wall of the first anti-reverse ring 3. A sealing ring can be embedded in the fourth sealing groove 301 to ensure a sealed connection between the first anti-reverse ring 3 and the inner wall of the pipe body 2. In addition, a first tooling hole 302 is provided on the first anti-reverse ring 3 to facilitate the assembly of the first anti-reverse ring 3.

[0113] In an optional embodiment of the present invention, such as Figures 1 to 3 As shown, the anti-impact wellbore enlargement device also includes a connecting cylinder 15 disposed inside the pipe body 2. The connecting cylinder 15 is a cylindrical shape disposed along the extension direction of the pipe body 2. The connecting cylinder 15 serves as a transitional connector between the central pipe 5 and the second fixed seat 18. The top of the connecting cylinder 15 is threadedly connected to the bottom of the central pipe 5, and the bottom of the connecting cylinder 15 is connected to the top of the second fixed seat 18 (i.e., at least part of the upper section of the second fixed seat 18 extends into the connecting cylinder 15 and is threadedly connected to the inner wall of the connecting cylinder 15).

[0114] In an optional embodiment of the present invention, such as Figures 1 to 3 , Figure 18 As shown, the anti-impact wellbore enlargement device also includes a cylindrical lower connector 21 and a second anti-reverse ring 20. The lower connector 21 is connected to the bottom end of the pipe body 2 by a thread. The lower connector 21 is used to connect with the lower drilling tool for drilling operations. The second anti-reverse ring 20 is disposed inside the pipe body 2 and pressed between the lower connector 21 and the second fixed seat 18. The outer wall of the second anti-reverse ring 20 is sealed to the inner wall of the pipe body 2.

[0115] Furthermore, such as Figure 18 As shown, a plurality of annular fifth sealing grooves 2001 are provided circumferentially on the outer wall of the second anti-reverse ring 20. A sealing ring can be embedded in the fifth sealing groove 2001 to ensure a sealed connection between the second anti-reverse ring 20 and the inner wall of the pipe body 2. In addition, a second tooling hole 2002 is provided on the second anti-reverse ring 20 for assembly of the second anti-reverse ring 20.

[0116] In an optional embodiment of the present invention, such as Figures 1 to 4 , Figure 9 , Figure 10As shown, the blade groove 201 is an elongated slot opened along the extension direction of the pipe body 2. The two opposite inner walls of the blade groove 201 each have multiple guide grooves 2011 that gradually slope upwards from the inside to the outside. The two opposite outer walls of the blade 11 each have multiple guide ribs 1101 that cooperate with the guide grooves 2011. The blade 11 is located within the blade groove 201, and the multiple guide ribs 1101 are slidably embedded in the multiple guide grooves 2011 in a one-to-one correspondence. Through the cooperation of the guide ribs 1101 and the guide grooves 2011, the blade 11 is guided to move upwards along the blade groove 201 while simultaneously moving outwards from the outside of the pipe body 2, thereby controlling the upward unfolding of the blade 11. In a specific embodiment of the present invention, the number of blade grooves 201 is three, and the three blade grooves 201 are spaced apart and evenly distributed along the circumference of the pipe body 2. The number of blades 11 is also three, to achieve stable cutting and diameter expansion of the wellbore.

[0117] Furthermore, such as Figure 9 , Figure 10 As shown, the cutter wing 11, facing outwards towards the pipe body 2, is provided with, from top to bottom, inverted reaming teeth 1104, diameter-maintaining teeth 1103, and cutting teeth 1102. The cutting teeth 1102 and inverted reaming teeth 1104 enable cutting operations on the wellbore inner wall in both forward and reverse rotation, achieving wellbore diameter enlargement. The end of the diameter-maintaining teeth 1103 abuts against the wellbore inner wall, providing stability and support. The specific structures of the inverted reaming teeth 1104, diameter-maintaining teeth 1103, and cutting teeth 1102 are existing technologies and are not specifically limited here. Of course, other arrangements or tooth shapes can also be used, as long as the preset diameter enlargement requirements are met.

[0118] In an optional embodiment of the present invention, such as Figures 1 to 3 , Figure 6 As shown, the first fixing seat 4 is cylindrical, and the outer wall of the first fixing seat 4 is threadedly connected to the inner wall of the tube body 2. The outer wall of the first fixing seat 4 and the inner wall of the tube body 2 are sealed together. The top of the central tube 5 extends into the inner side of the first fixing seat 4, and the outer wall of the central tube 5 and the inner wall of the first fixing seat 4 are threadedly connected. The outer wall of the central tube 5 and the inner wall of the first fixing seat 4 are sealed together.

[0119] Furthermore, such as Figure 6As shown, the outer wall of the first fixing seat 4 is provided with a plurality of annular sixth sealing grooves 401 along its circumference. Sealing rings can be embedded in the sixth sealing grooves 401 to ensure a sealed connection between the outer wall of the first fixing seat 4 and the inner wall of the tube body 2. The inner wall of the first fixing seat 4 is provided with a plurality of annular seventh sealing grooves 402 along its circumference. Sealing rings can be embedded in the seventh sealing grooves 402 to ensure a sealed connection between the inner wall of the first fixing seat 4 and the outer wall of the central tube 5. In addition, a first tooling groove 403 is provided on the top of the first fixing seat 4 for assembly.

[0120] Furthermore, such as Figures 1 to 3 As shown, the sleeve 6 is located below the first fixed base 4, and the top of the sleeve 6 is fixedly connected to the bottom of the first fixed base 4 by screws. The spring 7 is sleeved on the outer periphery of the central tube 5, and the top of the spring 7 abuts against the inner wall of the top of the sleeve 6. A first retaining ring 10 that can slide along the cutter blade groove 201 is provided above the cutter blade 11, and the bottom of the spring 7 abuts against the top of the first retaining ring 10. By setting the spring 7, a downward elastic force can be applied to the cutter blade 11, so that after the sliding sleeve 17 is closed to block the first passage 1801 and the drilling fluid can flow smoothly back into the well, the spring 7 can push the cutter blade 11 down and complete the retraction operation.

[0121] In an optional embodiment of the present invention, such as Figures 1 to 3 , Figures 7 to 10 As shown, a plurality of first support arms 1001 extending away from the center of the first retaining ring 10 are provided on the outer wall of the first retaining ring 10. The plurality of first support arms 1001 are spaced apart and evenly distributed along the circumference of the first retaining ring 10. The plurality of first support arms 1001 correspond one-to-one with a plurality of blade wing grooves 201, and the plurality of first support arms 1001 are slidably embedded in the corresponding blade wing grooves 201. The bottom of the first support arm 1001 has a first inclined surface 1004 at a first preset angle to the horizontal direction, and the top of the blade wing 11 has a second inclined surface 1105 (the second inclined surface 1105 at an angle α to the horizontal direction) opposite to the inclination direction of the first inclined surface 1004. The first inclined surface 1004 and the second inclined surface 1105 abut against each other. In a specific embodiment of the present invention, the first preset angle (i.e., the angle α between the second inclined surface 1105 and the horizontal direction) may be, but is not limited to, 5°. By setting the inclined surface, the blade 11 abuts against the first retaining ring 10 and the blade 11 is in the unfolded state. On the pushing surface of the blade 11 (i.e. the second inclined surface 1105), the blade 11 will be subjected to radial and axial components respectively, so as to improve the stability of the blade 11 during rock breaking.

[0122] Furthermore, the top of the first support arm 1001 has a first groove 1002, and the bottom wall of the first groove 1002 has a first threaded hole 1003. A baffle 8 is provided above the first support arm 1001. The bottom of the baffle 8 is embedded in the first groove 1002 and is fixed to the first threaded hole 1003 by screwing on the fixing bolt 9. The inner side wall of the baffle 8 is in contact with the outer wall of the sleeve 6. By cooperating with the baffles 8 on the multiple first support arms 1001 to hold the sleeve 6, the sleeve 6 and the first retaining ring 10 can be radially limited, ensuring that the spring 7 can apply force stably in the axial direction, and the elastic force of the spring 7 can be stably transmitted to the blade 11 through the first retaining ring 10.

[0123] In an optional embodiment of the present invention, such as Figures 9 to 13 As shown, a second retaining ring 12 is provided below the blade wing 11, which can slide along the blade wing groove 201. The second retaining ring 12 is threadedly connected to the top of the second fixed seat 18. A plurality of second support arms 1201 extending away from the center of the second retaining ring 12 are provided on the outer wall of the second retaining ring 12. The plurality of second support arms 1201 are spaced apart and evenly distributed along the circumference of the second retaining ring 12. The plurality of second support arms 1201 correspond one-to-one with the plurality of blade wing grooves 201. The plurality of second support arms 1201 are slidably embedded in the corresponding blade wing grooves 201. The first retaining ring 10, the blade wing 11 and the second retaining ring 12 are pressed together by the spring 7.

[0124] Furthermore, such as Figures 9 to 13 As shown, the top of the second support arm 1201 has a third inclined surface 1202 at a second preset angle to the horizontal direction, and the bottom of the blade 11 has a fourth inclined surface 1106 (the angle β between the fourth inclined surface 1106 and the horizontal direction is opposite to the inclination direction of the third inclined surface 1202) and the third inclined surface 1202 and the fourth inclined surface 1106 abut against each other. In a specific embodiment of the present invention, the second preset angle (i.e., the angle β between the fourth inclined surface 1106 and the horizontal direction) may be, but is not limited to, 5°. By setting the inclined surfaces (i.e., the cooperation between the first inclined surface 1004, the second inclined surface 1105, the third inclined surface 1202 and the fourth inclined surface 1106), the blade 11 abuts against the first retaining ring 10 and the second retaining ring 12 respectively, and the blade 11 in the deployed state can improve the stability of the blade 11 during rock breaking.

[0125] Furthermore, such as Figures 1 to 3 , Figures 11 to 13 As shown, a guide member 13 is sleeved on the outer side of the second support arm 1201, and the second support arm 1201 can be slidably embedded in the blade wing groove 201 through the guide member 13. Specifically, as shown... Figures 11 to 13As shown, the guide member 13 has a recess 1301, and flat keys 1302 are respectively provided on the two opposite inner walls of the recess 1301. Second grooves 1203 are respectively provided on the two opposite outer walls of the second support arm 1201. The second support arm 1201 is embedded in the recess 1301 and is engaged with the second grooves 1203 by the flat keys 1302. The guide member 13 serves to fill the gap between the second support arm 1201 and the blade slide groove 201, ensuring the stable sliding of the second retaining ring 12 within the blade slide groove 201. Of course, the thickness of the guide member 13 can be adjusted or the guide member 13 can be omitted depending on the actual gap size. In addition, a second threaded hole 1303 is provided on the guide member 13, and a third threaded hole 1204 is provided at the corresponding position on the second support arm 1201. Bolts are screwed into the second threaded hole 1303 and the corresponding third threaded hole 1204 to ensure a stable connection between the guide member 13 and the second support arm 1201.

[0126] Furthermore, such as Figures 1 to 3 As shown, the hydraulic cylinder body 16 has a vertically arranged cylindrical structure. The top outer wall of the hydraulic cylinder body 16 is threadedly connected to the inner wall of the second retaining ring 12, and the top outer wall of the hydraulic cylinder body 16 is sealed to the inner wall of the second retaining ring 12. This allows the upward movement of the hydraulic cylinder body 16 to push the second retaining ring 12, thereby pushing the blade 11 upward. The connecting cylinder 15, or at least the connecting cylinder 15, is located inside the hydraulic cylinder body 16.

[0127] Among them, such as Figures 1 to 3 , Figure 11 , Figure 14 As shown, the upper outer wall of the hydraulic cylinder body 16 has an annular groove 1602 along its circumference, and the guide member 13 has an arc-shaped protrusion 1304 on the side close to the hydraulic cylinder body 16. When the second retaining ring 12 is connected to the hydraulic cylinder body 16, the protrusion 1304 is precisely inserted into the groove 1602, thereby preventing the hydraulic cylinder body 16 from disengaging.

[0128] In an optional embodiment of the present invention, such as Figures 1 to 4 As shown, an annular eighth sealing groove 203 is provided on the inner wall of the tube body 2 below the blade slide groove 201, along the circumference of the tube body 2. A sealing ring is embedded in the eighth sealing groove 203, thereby ensuring a sliding sealing connection between the outer wall of the hydraulic cylinder body 16 and the inner wall of the tube body 2.

[0129] In an optional embodiment of the present invention, such as Figure 14As shown, a ninth sealing groove 1601 is formed on the upper inner wall of the hydraulic cylinder body 16 and circumferentially around the hydraulic cylinder body 16. A sealing ring is embedded in the ninth sealing groove 1601. The lower part of the central tube 5 passes through the hydraulic cylinder body 16 to ensure a sealed connection between the outer wall of the central tube 5 and the inner wall of the hydraulic cylinder body 16. In addition, a second tooling groove 1603 is formed at the bottom of the hydraulic cylinder body 16 to facilitate the assembly of the hydraulic cylinder body 16.

[0130] During operation, the anti-impact wellbore enlargement device of the present invention allows for independent drilling via the drill bit of the lower drilling tool before activation. After activation, the lower drilling tool can drill independently or simultaneously with the cutter wing 11, with the drill bit drilling while the cutter wing 11 enlarges the wellbore. Even after the anti-impact wellbore enlargement device is closed, independent drilling can still be performed via the drill bit of the lower drilling tool.

[0131] The working process of the anti-impact wellbore enlargement device of the present invention is as follows:

[0132] First, determine the drill string assembly and water nozzle 14 configuration based on the site conditions. Connect the assembled tools into the well in one go according to the drill string assembly. Before the anti-impact wellbore enlargement device is activated, the drilling fluid can be circulated normally. The lower drill string (lead drill bit) can be drilled independently. When reaming is required, an activation ball 22 is inserted into the central tube 5. The activation ball 22 sets and activates the sleeve 19, blocking the drilling fluid from flowing into the well. A pressure-stabilized area is formed above the activation ball 22. As the drilling fluid continues to flow in, the pressure above the activation ball 22 increases until the pressure in the central tube 5 cuts the first shear pin, causing the sleeve 19 to fall and the central tube 5 to connect with the hydraulic chamber 24 through the first port 1801. At this time, the drilling fluid in the central tube 5 can enter the hydraulic chamber 24 through the first port 1801 to push the hydraulic cylinder 16 upward. The hydraulic cylinder 16 pushes the cutter blade 11 upward along the cutter blade groove 201 and moves to the outside of the tube 2 to control the unfolding of multiple cutter blades 11. While keeping the cutter blades 11 in the unfolded position, the tube 2 is moved at a low speed to start reaming. It can be judged from the torque situation that after the cutter blades are fully opened, low-speed drilling begins to start reaming. Then, the rotation speed and drilling speed are gradually increased, and the drilling parameters are adjusted in real time. After drilling to the predetermined depth, a shut-off ball 23 is inserted into the central tube 5. Since the shut-off sleeve 17 is located above the first access port 1801, the shut-off ball 23 blocks the flow of drilling fluid into the hydraulic chamber 24. A pressure-stabilized area is formed above the shut-off ball 23, and the pressure inside the central tube 5 cuts off the second shear pin. The shut-off sleeve 17 falls to the position to seal the first access port 1801. The shut-off sleeve 17 performs the same function as the original activating sleeve 19, that is, to seal the first access port 1801. Under the action of the spring force 7, the cutter blade 11 moves down along the cutter blade groove 201 and moves towards the inside of the tube body 2, retracting into the tube body 2, completing the reaming operation, and the drill string is pulled out. The drilling fluid can circulate normally, and the cutter blade 11 no longer opens.

[0133] The features and advantages of the anti-impact wellbore enlargement device of the present invention are as follows:

[0134] I. This anti-impact wellbore enlargement device can be lowered into the wellbore to a preset position along with the drill string, and can carry out well enlargement operations while conducting exploratory drilling, thereby increasing the wellbore enlargement rate, preventing necking and stuck drill bits, and improving the annular clearance between the casing and the well wall.

[0135] Second, the anti-impact wellbore enlargement device uses a hydraulic drive for the deployment of the blade 11. Compared with other electric or mechanical drive methods, it has better stability and can effectively improve the vibration of the downhole drilling tools during well enlargement operations, thereby improving cementing quality and operational safety.

[0136] It should be noted that in the description of this application, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0137] The various embodiments described in this specification are presented in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0138] The above are merely a few embodiments of the present invention. Although the embodiments disclosed in the present invention are as described above, the content is only for the purpose of facilitating understanding of the present invention and is not intended to limit the present invention. Any person skilled in the art to which this invention pertains may make any modifications and changes in the form and details of the embodiments without departing from the spirit and scope disclosed in the present invention. However, the patent protection scope of the present invention shall still be determined by the scope defined in the appended claims.

Claims

1. An anti-impact wellbore enlargement device, characterized in that, The anti-impact wellbore enlargement device includes: The tube body has multiple blade grooves formed on its side wall along its length, and the multiple blade grooves are distributed at intervals along the circumference of the tube body; A central tube is fixedly installed inside the tube body and is used to supply drilling fluid. Multiple blades, wherein the multiple blades are slidably disposed within corresponding blade grooves; A sleeve is disposed inside the tube, the sleeve is located above the blade and sleeved on the outside of the central tube, the sleeve is connected to the tube through a first fixing seat, and a spring is disposed inside the sleeve and on the outer periphery of the central tube, the two ends of the spring abutting against the top inner wall of the sleeve and the top of the blade respectively. A hydraulic cylinder body is disposed inside the tube. The hydraulic cylinder body is located below the blade and is slidably sleeved on the outside of the central tube. A hydraulic chamber is formed on the inner side of the hydraulic cylinder body. The second fixing seat is disposed inside the pipe body and located below the hydraulic cylinder body. The second fixing seat is connected to the bottom of the central pipe and has at least one first through port. The second fixing seat extends into the hydraulic cavity at the location of the first through port. By controlling the opening and closing of the first through port, the communication state between the central pipe and the hydraulic cavity is adjusted. When the central pipe and the hydraulic cavity are in a communication state, the drilling fluid can push the hydraulic cylinder body upward to control the multiple cutter wings to move upward and outward to the outside of the pipe body.

2. The anti-impact wellbore enlargement device as described in claim 1, characterized in that, The anti-impact wellbore enlargement device further includes an activation sleeve and a closing sleeve, wherein the activation sleeve and the closing sleeve are respectively fixed in the second fixing seat by a first shear pin and a second shear pin, and the activation sleeve is located below the closing sleeve; The anti-impact wellbore enlargement device has an initial state, an activated state, and a closed state. When the anti-impact wellbore enlargement device is in its initial state, the activation sleeve blocks the first passage, and the drilling fluid can flow through the inside of the first fixed seat, the central tube, and the second fixed seat. When the anti-impact wellbore enlargement device is activated, an activation ball is inserted into the activation sleeve to block the flow of drilling fluid. The pressure in the central tube cuts off the first shear pin, the activation sleeve falls, and the central tube communicates with the hydraulic chamber through the first through port. The drilling fluid enters the hydraulic chamber to push the hydraulic cylinder upward. The hydraulic cylinder pushes the cutter blade upward along the cutter blade groove while moving outward to control the deployment of multiple cutter blades. When the anti-impact wellbore enlargement device is in the closed state, a closing ball is inserted into the closing sleeve to block the drilling fluid from flowing into the hydraulic chamber. The pressure in the central tube cuts off the second shear pin, and the closing sleeve falls to the position to block the first passage. The spring pushes the cutter blade down along the cutter blade groove and moves towards the inside of the pipe body to control the multiple cutter blades to retract into the pipe body.

3. The anti-impact wellbore enlargement device as described in claim 1 or 2, characterized in that, The anti-impact wellbore enlargement device also includes an upper connector and a first anti-reverse ring. The upper connector is connected to the top end of the pipe body and is used to connect to the upper drilling tool. The first anti-reverse ring is disposed in the pipe body and pressed between the upper connector and the first fixed seat. The outer wall of the first anti-reverse ring is sealed to the inner wall of the pipe body.

4. The anti-impact wellbore enlargement device as described in claim 1 or 2, characterized in that, The blade slide groove is an elongated slot opened along the extension direction of the tube body, and the two opposite inner walls of the blade slide groove each have a guide groove that gradually slopes upward from the inside to the outside. The blade has guide ribs on its two opposite outer walls that cooperate with the guide groove. The blade is located in the blade groove, and the guide ribs are slidably embedded in the corresponding guide grooves to guide the blade to move upward along the blade groove while moving outward to the outside of the tube.

5. The anti-impact wellbore enlargement device as described in claim 4, characterized in that, The first fixing seat is cylindrical, and the outer wall of the first fixing seat is sealed to the inner wall of the tube. The top of the central tube extends into the inner side of the first fixing seat, and the outer wall of the central tube is sealed to the inner wall of the first fixing seat.

6. The anti-impact wellbore enlargement device as described in claim 5, characterized in that, The sleeve is located below the first fixed base, and the top of the sleeve is connected to the bottom of the first fixed base. The spring is sleeved on the outer periphery of the central tube, and the top of the spring abuts against the inner wall of the top of the sleeve. A first retaining ring is provided above the blade wing, which can slide along the blade wing groove, and the bottom of the spring abuts against the top of the first retaining ring.

7. The anti-impact wellbore enlargement device as described in claim 6, characterized in that, The outer wall of the first retaining ring is provided with a plurality of first support arms extending away from the center of the first retaining ring. The plurality of first support arms are distributed at intervals along the circumference of the first retaining ring and correspond one-to-one with the plurality of blade wing grooves. The plurality of first support arms are slidably embedded in the corresponding blade wing grooves.

8. The anti-impact wellbore enlargement device as described in claim 7, characterized in that, The bottom of the first support arm has a first inclined surface at a first preset angle to the horizontal direction, and the top of the blade has a second inclined surface in the opposite direction to the first inclined surface, with the first inclined surface abutting against the second inclined surface.

9. The anti-impact wellbore enlargement device as described in claim 6, characterized in that, A second retaining ring is provided below the blade wing, which can slide along the blade wing groove, and the second retaining ring is connected to the top of the second fixing seat; The outer wall of the second retaining ring is provided with a plurality of second support arms extending away from the center of the second retaining ring. The plurality of second support arms are distributed at intervals along the circumference of the second retaining ring and correspond one-to-one with the plurality of blade wing grooves. The plurality of second support arms are slidably embedded in the corresponding blade wing grooves. The spring presses the first retaining ring, the blade, and the second retaining ring together.

10. The anti-impact wellbore enlargement device as described in claim 9, characterized in that, The top of the second support arm has a third inclined surface that forms a second preset angle with the horizontal direction, and the bottom of the blade has a fourth inclined surface that is in the opposite direction to the third inclined surface. The third inclined surface and the fourth inclined surface abut against each other.

11. The anti-impact wellbore enlargement device as described in claim 2, characterized in that, The lower inner wall of the activation sleeve has a ring-shaped first shoulder that tapers from top to bottom. The diameter of the activation ball is larger than the inner diameter of at least part of the first shoulder, so that the activated ball can be seated on the first shoulder when it is inserted.

12. The anti-impact wellbore enlargement device as described in claim 11, characterized in that, The lower inner wall of the closing sleeve is formed with a ring-shaped second shoulder that gradually narrows from top to bottom. The diameter of the closing ball is larger than the inner diameter of at least part of the second shoulder, so that the inserted closing ball can sit and seal on the second shoulder. The diameter of the activation ball is smaller than the inner diameter of the second shoulder, so that the activation ball can pass through the closing sleeve and fall into the activation sleeve.

13. The anti-impact wellbore enlargement device as described in claim 11, characterized in that, The second fixing seat is a cylindrical shape arranged along the extension direction of the pipe body. A cavity is formed inside the second fixing seat. The first through port is located above the cavity. A second through port is arranged on the second fixing seat and below the cavity. The cavity is connected to the pipe body through the second through port and the annular space between the second fixing seat and the pipe body. A flow channel is opened on the pipe wall of the pipe body at a position opposite to the second fixing seat. The drilling fluid in the cavity can be discharged outward in sequence through the second through port and the flow channel. The flow channel is equipped with a water nozzle to control its on / off state.

14. The anti-impact wellbore enlargement device as described in claim 1 or 2, characterized in that, The anti-impact wellbore enlargement device also includes a connecting cylinder disposed inside the pipe body, the top of the connecting cylinder being connected to the bottom of the central pipe, and the bottom of the connecting cylinder being connected to the top of the second fixing seat.

15. The anti-impact wellbore enlargement device as described in claim 1 or 2, characterized in that, The anti-impact wellbore enlargement device also includes a lower connector and a second anti-reverse ring. The lower connector is connected to the bottom end of the pipe body and is used to connect with the lower drilling tool. The second anti-reverse ring is disposed in the pipe body and pressed between the lower connector and the second fixed seat. The outer wall of the second anti-reverse ring is sealed to the inner wall of the pipe body.

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