A door opening type reamer while drilling wing

Abstract

The application discloses a door-opening type blade wing while-drilling reamer, and belongs to the technical field of downhole tools for oil and gas drilling. The reamer shell is provided with a blade wing bin, the upper and lower short shaft heads on one side of the blade wing are rotationally matched with two blade wing support sleeves fixed to the inner wall of the shell, and a fixed door-opening rotating shaft is formed; the inner side of the blade wing is provided with a follow-up roller through a short rocker arm, and the follow-up roller is matched with an arc-shaped guide groove on the cam sleeve. A first ball is thrown to move a lower ball seat and connect a piston cavity, high-pressure drilling fluid drives an annular driving piston and the cam sleeve to move axially, so that the blade wing is unfolded outward around a fixed axis; a second ball is thrown to move an upper ball seat and cut off a flow passage of the piston cavity, and a compression spring drives the blade wing to be retracted into the blade wing bin. The reamer can bear the cutting load of the blade wing through the support sleeve, can limit the opening and closing track through the cam roller pair, and can keep the blade wing retracted when the drilling fluid circulation is restored, so that the transmission jamming, the mis-unfolding of the blade wing and the risk of encountering resistance in the downhole can be reduced.

Description

Technical Field

[0001] This invention relates to the field of downhole tools technology for oil and gas drilling, specifically to a drilling reamer that utilizes a fixed hinge support and cam roller drive to achieve fixed-axis opening and closing of the cutter blades, and uses a two-stage ball dropping mechanism to switch the hydraulic activation state. Background Technology

[0002] During the drilling of deep wells, ultra-deep wells, horizontal wells, and wells with complex structures, it is often necessary to enlarge the wellbore diameter in the target section to improve casing installation, cementing, and wellbore cleaning conditions. A reamer can be run into the well with the drill string and deploy its blades in the target section to complete the reaming, reducing the tripping and tripping operations required for dedicated reaming.

[0003] Some existing hydraulic reamers use pistons to directly radially push the blade, wedges to extend the blade, or movable connecting rods to drive the blade. When the blade lacks a fixed pivot constraint, the driving component and the blade are prone to a coupled motion of translation and oscillation. The blade's unfolding radius and opening / closing trajectory are greatly affected by assembly clearance, cutting reaction force, and impact vibration. The transmission pair may also bear the cutting load that should be borne by the support structure.

[0004] Some drilling reamers rely on stopping the pump to depressurize the drive chamber and retract the cutter wings. If the high-pressure flow channel reconnects with the drive chamber after drilling fluid circulation is restored, the cutter wings may re-deploy, making it difficult for the tool to continue circulating in the retracted state or to pass through narrow-diameter well sections. If the retracted cutter wings protrude significantly from the outer casing, it also increases the risk of obstruction during lowering and retrieval.

[0005] Therefore, there is a need for a drilling reamer that can clearly separate the blade support bearing path from the cam drive path, enable the blade to open and close along a predetermined trajectory, and maintain a deactivated state while maintaining the main circulation of drilling fluid. Summary of the Invention

[0006] The purpose of this invention is to provide an open-type cutter wing drilling reamer to solve the problems of the cutter wing opening and closing trajectory being easily affected by load disturbance, excessive load on the drive pair, the possibility of the cutter wing re-expanding after retraction and recovery of the cycle, and the retracted shape being unfavorable for tool passage.

[0007] To achieve the above objectives, the present invention provides an open-type reamer with a cutting edge during drilling, comprising a reamer housing, a cutting edge, a cutting edge support sleeve, a cam sleeve, a follower roller, a short rocker arm for the cutting edge, an annular drive piston, an integral mandrel, a compression spring, a drive ring, an upper ball seat, a lower ball seat, an upper cap, and a lower cap. The reamer housing is provided with a cutting edge compartment corresponding to the cutting edge.

[0008] The blade assembly includes a blade, a short blade rocker arm, and a follower roller. Two short shaft ends are coaxially positioned near one edge of the blade. Two blade support sleeves, located at opposite ends of the blade compartment's axial direction, are fixed to the inner wall of the expander housing. The two short shaft ends rotatably engage with the two blade support sleeves, thus forming a fixed-position blade shaft supported by the housing.

[0009] A short rocker arm is connected to the inner side of the blade wing, and a follower roller is rotatably mounted on the free end of the short rocker arm. A cam sleeve is fitted around the integral spindle and is axially movable. The cam sleeve has an arc-shaped guide groove to accommodate the follower roller. The drive mechanism drives the cam sleeve to move axially, and the arc-shaped guide groove applies torque to the blade wing through the follower roller and the short rocker arm, causing the blade wing to rotate around a fixed blade wing axis between a retracted position and an extended position.

[0010] Preferably, the arc-shaped guide groove is a closed guide groove that constrains the follower roller from both sides, and includes a retraction holding section, a transition drive section, and an expansion holding section; the transition drive section is determined according to the position of the blade shaft, the effective length of the blade short rocker arm, and the predetermined expansion angle, so that the axial displacement of the cam sleeve matches the arc motion of the follower roller.

[0011] Preferably, the drive mechanism includes an annular drive piston, and the elastic reset mechanism includes a compression spring and a drive ring. The annular drive piston is drivenly connected to the cam sleeve, and the compression spring is sleeved outside the integral mandrel and applies a reset force to the cam sleeve through the drive ring. When the annular drive piston is compressed, it drives the blade to unfold; when the annular drive piston is decompressed, the compression spring drives the blade to retract.

[0012] Preferably, the borehole reamer further includes a ball-launching hydraulic control mechanism. The ball-launching hydraulic control mechanism includes an upper ball seat and a lower ball seat, which are arranged along the drilling fluid flow direction and held in their initial positions by a shearable limiting member. A first ball-launcher can pass through the upper ball seat and seal with the lower ball seat, causing the lower ball seat to move to an activated position that connects the piston chamber by pressurization; a second ball-launcher can seal with the upper ball seat, causing the upper ball seat to move to a deactivated position that cuts off the high-pressure flow path of the piston chamber by pressurization.

[0013] Preferably, the integral mandrel has a central drilling fluid channel leading to the drill bit. When the upper ball seat moves to the deactivated position, the piston chamber is isolated from the high-pressure drilling fluid, while the central drilling fluid channel is opened or remains connected, allowing the cutter blades to continue circulating drilling fluid in the retracted state.

[0014] Compared with the prior art, the present invention has at least the following beneficial effects:

[0015] First, the two blade support sleeves and the upper and lower short shaft ends of the blade form a fixed hinged support, which allows the main cutting reaction force and impact load to be transmitted to the expander housing through the blade support sleeves; the cam groove-roller pair mainly undertakes the opening and closing drive function, thereby reducing the interference of cutting load on the drive trajectory and reducing the possibility of overload, misalignment and jamming of the transmission pair.

[0016] Second, the fixed blade shaft and the arc-shaped guide groove designed according to the motion relationship together limit the opening and closing trajectory of the blade, so that the blade can repeat the action according to the predetermined unfolding angle and the enlargement radius; the closed guide groove forms a reverse traction on the follower roller when resetting, which is conducive to the blade actively retracting along the original path, thereby improving the controllability of the enlargement size and the reliability of the mechanism reset.

[0017] Third, the first ball drop establishes the reaming activation state, and the second ball drop establishes the reaming deactivation state. After the second ball drop is completed, even if drilling fluid circulation is restored, the piston chamber remains isolated from the high-pressure drilling fluid, and the cutter blades remain retracted, reducing the risk of accidental deployment in non-reaming sections and the resulting obstruction or jamming, while maintaining drilling fluid delivery to the drill bit.

[0018] Fourth, after the cutter wing retracts, it is embedded in the cutter wing compartment that matches its shape. The outer side is basically flush with the outer arc surface of the reamer housing, which can reduce the resistance during the tool's entry and exit. The cam sleeve, annular drive piston, and return spring are arranged around the overall spindle, which is beneficial for utilizing the limited downhole radial space.

[0019] Fifth, the rolling engagement between the follower roller and the arc-shaped guide groove can reduce sliding friction during the opening and closing process; the roller shaft end is equipped with a retaining ring, shoulder or locking structure to reduce the risk of the follower roller axially dislodging under high-speed rotation and vibration conditions. Attached Figure Description

[0020] Figure 1 This is a schematic cross-sectional view of the overall structure of the door-type cutter wing drilling reamer of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal transmission structure of the eye expander of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the blade, the short rocker arm of the blade, and the follower roller of the present invention;

[0023] Figure 4 This is a schematic diagram of the outer shell, blade compartment, and blade support structure of the eye expander of the present invention;

[0024] Figure 5 This is a schematic diagram of the structure of the cam sleeve and arc-shaped guide groove of the present invention;

[0025] Explanation of reference numerals in the attached diagram: 1. Upper cap; 2. Compression spring; 3. Drive ring; 4. Cam sleeve; 5. Blade; 6. Follower roller; 7. Annular drive piston; 8. Upper ball seat; 9. Integral spindle; 10. Lower ball seat; 11. Lower cap; 12. Roller shaft end retaining ring; 13. Blade short rocker arm; 14. Upper and lower short shaft ends of the blade; 15. Arc-shaped guide groove; 16. Expander housing; 17. Nozzle mounting hole and countersunk seat; 18. Blade support sleeve; 19. Blade compartment. Detailed Implementation

[0026] The structure and operation of the present invention will be further described below with reference to the accompanying drawings. The embodiments described are for illustrative purposes only and are not intended to limit the scope of protection of the present invention; where there is no conflict, the technical features of the various embodiments can be combined with each other.

[0027] like Figures 1 to 5 As shown, the expander in this embodiment includes an upper cap 1, a compression spring 2, a drive ring 3, a cam sleeve 4, a blade 5, a follower roller 6, an annular drive piston 7, an upper ball seat 8, an integral spindle 9, a lower ball seat 10, a lower cap 11, a roller shaft end retaining ring 12, a blade short rocker arm 13, upper and lower short shaft heads of the blade 14, an arc-shaped guide groove 15, an expander housing 16, a nozzle mounting hole and countersunk seat 17, a blade support sleeve 18, and a blade compartment 19.

[0028] like Figure 1 As shown, the reamer housing 16 is a hollow cylindrical structure, with the integral mandrel 9 running through it along the central axis of the reamer housing 16. The upper cap 1 and lower cap 11 are located at opposite axial ends of the tool, used for axial positioning of the internal mechanism. The compression spring 2, drive ring 3, cam sleeve 4, annular drive piston 7, upper ball seat 8, and lower ball seat 10 are arranged sequentially around the integral mandrel 9, forming a central drilling fluid channel inside the integral mandrel 9. The cutter wing 5 is located on one side of the reamer housing 16, with the upper and lower short shaft ends 14 forming the fixed rotating shaft of the cutter wing. The follower roller 6 and the arc-shaped guide groove 15 on the cam sleeve 4 form a transmission engagement. Figure 1 The overall assembly relationship of the above components in the reamer in the axial and radial directions is shown; when the reamer is in an inactive, active or deactivated state, drilling fluid can be supplied to the drill bit according to the flow channel position of the control section.

[0029] The eye expander housing 16 has a blade compartment 19 in the middle. The blade compartment 19 includes a curved surface fitting area adapted to the outer side of the blade 5 and a movement window communicating with the inner cavity of the housing. When the blade 5 is in the retracted position, it is embedded in the blade compartment 19, and the height difference between the outer side of the blade 5 and the outer circle of the eye expander housing 16 is controlled within a range that does not affect the passage of the tool.

[0030] The blade wing 5 has two coaxial short shaft heads 14 near one edge. The two short shaft heads 14 are preferably machined integrally with the blade wing 5, but they can also be manufactured separately and then fixedly connected. Two blade wing support sleeves 18 are fixed to the inner wall of the expander housing 16 and are located at the two axial ends of the blade wing compartment 19, respectively; the two short shaft heads 14 are respectively inserted into the inner holes of the corresponding blade wing support sleeves 18 to form a rotating pair.

[0031] The aforementioned revolute joint limits the motion freedom of the cutter blade 5 to rotation around a single fixed axis. During reaming, the radial cutting reaction force, impact load, and axial lateral force acting on the cutter blade 5 from the well wall are mainly transmitted to the reamer housing 16 through the short shaft head 14 and the cutter blade support sleeve 18. This allows the follower roller 6 and the arc-shaped guide groove 15 to primarily generate opening and closing torque, rather than serving as the sole load-bearing support point of the cutter blade 5.

[0032] The short rocker arm 13 of the blade wing is connected to the inner side of the blade wing 5. The short rocker arm 13 can be integrally formed, welded, tenoned, or fixed with fasteners. The free end of the short rocker arm 13 is provided with a roller shaft, and the follower roller 6 is sleeved on the roller shaft and can rotate around the roller shaft, which can greatly reduce the friction of the follower roller and prevent its axial movement. A roller shaft end retaining ring 12 is provided at the outer end of the roller shaft; in other embodiments, a shaft shoulder, a lock nut, a cotter pin, or a combination thereof can also be used to restrict the axial movement of the follower roller 6.

[0033] The cam sleeve 4 is coaxially sleeved outside the integral spindle 9 and can move axially within the eye expander housing 16. The cam sleeve 4 is provided with an arc-shaped guide groove 15, and the follower roller 6 is located within the arc-shaped guide groove 15. The arc-shaped guide groove 15 is preferably a closed groove, so that the two side walls of the groove can apply force to the follower roller 6 during the unfolding stroke and the retracting stroke, respectively.

[0034] The arc-shaped guide groove 15 includes a retraction holding section, a transition drive section, and an expansion holding section. The spatial trajectory of the transition drive section is determined according to the position of the blade shaft, the effective length of the blade short rocker arm 13, the diameter of the follower roller 6, and the predetermined expansion angle of the blade 5, so that the axial displacement of the cam sleeve 4 is coordinated with the arc motion of the follower roller 6 around the fixed blade shaft. The retraction holding section and the expansion holding section can be set as gradually changing sections that are relatively insensitive to axial displacement, so as to improve the stability of the end position.

[0035] The annular drive piston 7 is located at one end of the cam sleeve 4 and is directly connected to, abuts against, or is connected to the cam sleeve 4 through an intermediate force transmission component. The compression spring 2 is sleeved on the outside of the integral spindle 9. One end of the compression spring 2 is positioned by the upper cap 1 or the fixed spring seat, and the other end applies a preload force to the cam sleeve 4 in the retraction direction through the drive ring 3.

[0036] The ball-throwing hydraulic control mechanism is located downstream of the annular drive piston 7 and includes an upper ball seat 8 and a lower ball seat 10. Both the upper ball seat 8 and the lower ball seat 10 can move axially within the control section and are held in their initial positions by a shear pin and a shear ring, respectively. The control section includes a pressure supply channel communicating with the piston chamber and a main circulation channel communicating with the central channel of the integral spindle 9.

[0037] The outer diameter of the first ball is smaller than the ball hole of the upper ball seat 8, allowing it to pass through the upper ball seat 8 and seal with the lower ball seat 10. When the mud pump continues to supply liquid, a pressure difference is established upstream of the first ball; after the pressure difference reaches the first set value, the shearable limiting member of the lower ball seat 10 is disconnected, and the lower ball seat 10 moves to the activated position, connecting the pressure supply channel with the piston chamber.

[0038] High-pressure drilling fluid enters the piston chamber through the pressure supply channel, forming axial hydraulic pressure on the effective pressure-bearing area of ​​the annular drive piston 7. This hydraulic pressure overcomes the preload of the compression spring 2 and the sealing friction, pushing the annular drive piston 7 and the cam sleeve 4 to move in the activation direction. The groove wall of the arc-shaped guide groove 15 pushes the follower roller 6, which applies torque to the cutter wing 5 via the cutter wing short rocker arm 13, causing the cutter wing 5 to unfold outward from the cutter wing chamber 19 around the fixed axis defined by the two cutter wing support sleeves 18.

[0039] After the follower roller 6 enters the deployment holding section, the cutter wing 5 reaches the predetermined deployment angle. Maintaining the mud pump discharge and piston chamber pressure, the annular drive piston 7 remains at the active stroke end, and the cutter wing 5 rotates with the reamer housing 16 in the deployed state, cutting the well wall. The cutter wing support sleeve 18 bears the main cutting load, and the arc-shaped guide groove 15 maintains the deployed position of the cutter wing 5.

[0040] When it is necessary to temporarily retract the blade wing 5, the mud pump can be stopped or the pump pressure reduced, causing the piston chamber pressure to decrease. The compression spring 2 releases its elastic potential energy and pushes the cam sleeve 4 to move in the reset direction through the drive ring 3. The closed arc-shaped guide groove 15 pulls the follower roller 6 in the opposite direction, the blade short rocker arm 13 swings in the opposite direction, and the blade wing 5 retracts into the blade wing compartment 19 around the same fixed axis.

[0041] The outer diameter of the second ball is larger than the ball passage of the upper ball seat 8, and it can seal with the upper ball seat 8. After the hole is enlarged, the second ball is inserted and pumping continues, and a pressure difference is established upstream of the second ball. After the pressure difference reaches the second set value, the shearable limiter of the upper ball seat 8 is disconnected, and the upper ball seat 8 moves to the deactivation position, blocking or offsetting the pressure supply channel, so that the piston chamber is isolated from the high-pressure drilling fluid.

[0042] When the upper ball seat 8 reaches the deactivation position, the main circulation channel of the integral mandrel 9 is simultaneously opened or kept open. This compresses the spring 2, keeping the cutter blades 5 retracted, while drilling fluid can still flow to the drill bit via the integral mandrel 9. This configuration prevents the cutter blades 5 from re-deploying due to renewed pressure in the piston chamber when full-flow circulation is resumed in non-reamed sections.

[0043] The reamer housing 16 may also be provided with a nozzle mounting hole and a countersunk hole seat 17. The nozzle mounting hole is positioned to avoid the cutter wing compartment 19, the cutter wing support sleeve 18, and the motion envelope of the cutter wing 5 from the retracted position to the deployed position. After the nozzle is installed, some drilling fluid can be directed to the cutter wing cutting area and the well wall for cooling the cutter wing, cleaning the cutting surface, and assisting in carrying away rock cuttings.

[0044] The fixed connection in this invention can be achieved through welding, threaded connection, interference fit, retaining ring, or detachable gland, depending on manufacturing, assembly, and maintenance needs. The arc-shaped guide groove 15 can be directly machined from the cam sleeve 4, or it can be formed from a groove plate fixed to the cam sleeve 4. Any equivalent substitutions based on the fixed blade shaft, the cam groove driving roller, and the two-stage ball-throwing switching piston pressure state do not depart from the technical concept of this invention.

[0045] To facilitate the explanation of the functional division of each key structure in the opening-type blade movement, Table 1 lists the main structures and their functions in this embodiment.

[0046] Table 1. Correspondence between key structures and functions

[0047] 1 Cutter wing upper and lower short shaft heads 14, cutter wing support sleeve 18 It forms a fixed rotating shaft, restricting the blade to rotate only around a single axis, and transmitting the cutting reaction force and impact load to the expander housing. 2 Blade 5, Blade short rocker arm 13 The door opening actuator is formed, which converts the driving force at the follower roller into the torque of the blade rotating around a fixed axis. 3 Follower roller 6, roller shaft end retaining ring 12 It rolls into contact with the arc-shaped guide groove to reduce friction; the retaining ring is used to prevent the follower roller from axially disengaging. 4 Cam sleeve 4, arc-shaped guide groove 15 The axial displacement of the cam sleeve is converted into the fixed-axis rotation of the blade, and the closing, driving and unfolding holding sections are defined. 5 7. Ring-shaped drive piston, 8. Upper ball seat, 10. The first shot activates the piston chamber to drive deployment, and the second shot disconnects the piston chamber to deactivate it. 6 Compression spring 2, drive ring 3 After the piston chamber loses pressure, a restoring force is provided, causing the cam sleeve and the blade to return along the opposite path. 7 integral spindle 9 It forms a central drilling fluid channel, delivering drilling fluid to the drill bit during activation, deactivation, and reset processes. 8 Eye expander housing 16, blade compartment 19, nozzle mounting hole 17 It accommodates and protects the transmission mechanism, ensuring that the cutter blade is basically flush with the outer circle after closing, and delivers drilling fluid to the cutting area.

[0048] Table 2 lists the flow channel status, mechanism actions, and blade status for each stage: inactive, activated, temporarily reclaimed, and deactivated.

[0049] Table 2 Throwing Control Status and Results

[0050] Initial entry No ball was thrown; the central drilling fluid channel remained connected. The compression spring remains preloaded, and the cam sleeve is at the retracted end. Retrieved from the bladed warehouse Start eye expansion The first pitch passes through the upper saddle and lands on the lower saddle; the lower saddle shifts, connecting the piston chamber. The ring-driven piston pushes the cam sleeve to move axially. Expand outward around a fixed axis Keep your eyes open Continuous pumping and high-pressure drilling fluid maintain piston chamber pressure The follower roller is located in the unfolding and holding section of the arc-shaped guide groove. Keep unfolded and cut the well wall Temporary recycling Stopping the pump or reducing the pump pressure causes the piston chamber to lose pressure. The compression spring pushes the cam sleeve back. Temporarily withdrawn End eye dilation and restore circulation The second ball rests on the upper ball seat; the upper ball seat shifts and cuts off the piston chamber flow path, while the central drilling fluid passage opens or remains connected. The reset mechanism drives the cam sleeve, follower roller, and short rocker arm to reset, while the drive mechanism remains deactivated. Keep it retracted and do not unfold it again.

Claims

1. A door-opening type reamer for drilling, characterized in that, include: The eye expander housing (16), blade (5), blade support assembly, cam sleeve (4), follower roller (6), blade short rocker arm (13) and drive mechanism; The outer shell (16) of the eye expander is provided with a blade wing compartment (19). The outer side of the blade wing (5) is adapted to the outer arc surface of the outer shell (16) of the eye expander. The blade wing (5) is provided with a coaxial first short shaft head and a second short shaft head near one side edge. The blade wing support assembly includes a first blade wing support sleeve and a second blade wing support sleeve fixed to the inner wall of the outer shell (16) of the eye expander. The first short shaft head and the second short shaft head are respectively rotatably engaged with the first blade wing support sleeve and the second blade wing support sleeve to limit the rotation of the blade wing (5) around a fixed axis. The inner side of the blade wing (5) is connected to the blade wing short rocker arm (13), and the end of the blade wing short rocker arm (13) is equipped with the follower roller (6); the cam sleeve (4) can move along the axial direction of the eye expander and is provided with an arc-shaped guide groove (15) to accommodate the follower roller (6); the drive mechanism is connected to the cam sleeve (4) for driving the cam sleeve (4) to move axially, so that the arc-shaped guide groove (15) pushes the follower roller (6) and the blade wing short rocker arm (13) to swing, thereby causing the blade wing (5) to rotate outward from the blade wing compartment (19) around the fixed axis.

2. The open-type cutter wing drilling reamer according to claim 1, characterized in that: The first short shaft head and the second short shaft head together constitute the upper and lower short shaft heads (14) of the blade wing and are integral with the blade wing (5); the first blade wing support sleeve and the second blade wing support sleeve together constitute the blade wing support sleeve (18). The inner holes of the two blade wing support sleeves (18) are coaxially arranged and located on the outer sides of the axial ends of the blade wing compartment (19) respectively, so as to jointly bear the radial load, impact load and axial force when the blade wing (5) is cutting; when the blade wing (5) is in the retracted position, it is embedded in the blade wing compartment (19), and the outer side of the blade wing (5) is basically flush with the outer arc surface of the eye expander housing (16).

3. The open-type cutter wing drilling reamer according to claim 1, characterized in that: The arc-shaped guide groove (15) is a closed guide groove that can constrain the follower roller (6) from both sides. The arc-shaped guide groove (15) includes a closed holding section, a transition driving section and an unfolding holding section. The trajectory of the transition driving section is determined according to the position of the fixed axis, the length of the blade short rocker arm (13) and the motion arc of the follower roller (6). The follower roller (6) is mounted on the end of the blade short rocker arm (13) through a roller shaft and can rotate around the roller shaft. The outer end of the roller shaft is provided with a roller shaft end retaining ring (12), a shoulder, a nut or a combination thereof.

4. The open-type cutter wing drilling reamer according to claim 1, characterized in that, The device includes an integral spindle (9) and an elastic reset mechanism. The drive mechanism includes an annular drive piston (7) that is connected to the cam sleeve (4) for transmission. The elastic reset mechanism includes a compression spring (2) sleeved on the outside of the integral spindle (9) and a drive ring (3) that abuts against the compression spring (2). When the annular drive piston (7) is pressed, it drives the cam sleeve (4) to move and causes the blade (5) to unfold. When the annular drive piston (7) is depressurized, the compression spring (2) pushes the cam sleeve (4) back through the drive ring (3), causing the arc-shaped guide groove (15) to reverse and drive the follower roller (6), the blade short rocker arm (13) and the blade (5) back to the retracted position.

5. The open-type cutter wing reamer according to claim 4, characterized in that: The system includes a ball-throwing hydraulic control mechanism, comprising an upper ball seat (8) and a lower ball seat (10) arranged along the drilling fluid flow direction. The upper ball seat (8) and the lower ball seat (10) are respectively held in their initial positions by shearable limiting members. A first ball can pass through the upper ball seat (8) and seal with the lower ball seat (10) to move the lower ball seat (10) after pressure buildup and connect to the piston chamber leading to the annular drive piston (7). After the lower ball seat (10) moves, high-pressure drilling fluid enters the piston chamber and forms a pressure difference at both ends of the annular drive piston (7). A second ball can seal with the upper ball seat (8) to move the upper ball seat (8) after pressure buildup and close the flow channel leading to the piston chamber.

6. The open-type cutter wing reamer according to claim 5, characterized in that: It also includes an upper cap (1) and a lower cap (11). The integral mandrel (9) passes through the upper cap (1), compression spring (2), drive ring (3), cam sleeve (4), annular drive piston (7), upper ball seat (8) and lower ball seat (10) to form a continuous central drilling fluid channel. After the upper ball seat (8) moves, it isolates the piston chamber from the high-pressure drilling fluid and opens or maintains the central drilling fluid channel. The reamer housing (16) is also provided with a nozzle mounting hole and a countersunk hole seat (17) that avoid the cutter wing chamber (19), cutter wing support sleeve (18) and cutter wing motion envelope.

7. A method for reaming holes using the open-type cutter wing reamer as described in claim 5 or 6, characterized in that, include: The open-type reamer is lowered into the target well section, and the reamer (5) is kept retracted in the reamer compartment (19). The first ball is dropped, and the first ball passes through the upper ball seat (8) and seals with the lower ball seat (10). The mud pump continues to supply fluid to establish a pressure difference, causing the shearable limiting element of the lower ball seat (10) to disconnect and the lower ball seat (10) to move, connecting the piston chamber. The high-pressure drilling fluid entering the piston chamber pushes the annular drive piston (7) and cam sleeve (4) to move axially, and the arc-shaped guide groove (15) pushes the follower roller (6) and the reamer short rocker arm (13) to make the reamer (5) rotate outward around the fixed axis defined by the two reamer support sleeves (18). The drilling fluid pressure is maintained so that the reamer (5) remains deployed and the reaming is completed. After the eye expansion is completed, the second ball is thrown, so that the second ball is sealed and fitted with the upper ball seat (8) and a pressure difference is established, so that the shearable limiting member of the upper ball seat (8) is disconnected and moved, closing the flow channel to the piston chamber, and the cam sleeve (4), follower roller (6), blade short rocker arm (13) and blade (5) are reset in sequence by using the compression spring (2).

8. The working method according to claim 7, characterized in that: Before the second ball is dropped, the piston chamber pressure is reduced by stopping the pump, and the blade (5) is temporarily retracted under the action of the compression spring (2). After the second ball is dropped, the piston chamber is kept isolated from the high-pressure drilling fluid when the drilling fluid circulation is restored, so that the blade (5) remains in the retracted state and the drilling fluid continues to flow to the drill bit through the central drilling fluid channel of the integral mandrel (9).

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