Self-locking type multistage helical tooth reducing reamer while drilling

Abstract

The invention relates to the field of drilling equipment, and discloses a self-locking multistage helical tooth reducing reamer while drilling, which comprises an upper joint, a mandrel body, a lower joint and a shell, and further comprises a ball throwing seat arranged on one side, far away from the upper joint, of the mandrel body and movably arranged in the lower joint; the reaming unit is arranged on the mandrel body, penetrates through a moving groove formed in the shell, moves along with the mandrel body and is used for adjusting the reaming diameter of the reamer; and the control unit is arranged on the mandrel body and located in the shell, three-level size reaming can be achieved underground, the reaming difficulty is remarkably reduced, and the functions of blade reaming locking and autonomous reverse jam releasing are integrated; while the integration of multiple functions is realized, the uplink and downlink travel conflict of locking and unblocking is effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of drilling equipment, in particular to a self-locking multi-stage helical tooth variable diameter while drilling reamer. Background Art

[0002] The hole-while-drilling (LWD) reamer plays an important role in the energy drilling industry. As a typical innovative drilling tool, its development level reflects the country's energy drilling development level. In the field of oil, natural gas and other drilling projects, the hole-while-drilling (LWD) reamer is an important downhole tool. Its main function is to expand the wellbore diameter during the drilling process to meet the requirements of different geological conditions and drilling processes. Most of the hole-while-drilling (LWD) reamers on the market are mainly activated by the pressure difference between the ball injection and the hydraulic pressure of the drilling fluid, and are controlled through the flow channel.

[0003] Existing equipment suffers from the following drawbacks: Existing drilling equipment cannot flexibly adjust the hole diameter according to actual needs during the drilling process. Once the design is finalized, the hole size is relatively fixed. This makes it difficult to meet the diverse wellbore size requirements in complex and variable formations, increasing the difficulty and cost of drilling operations. For example, when encountering alternating soft and hard formations, a fixed-diameter reamer may not be able to effectively reame the hole in soft formations, while in hard formations, excessive reaming resistance may cause tool damage.

[0004] Therefore, the present application proposes a self-locking multi-stage helical tooth variable diameter reamer while drilling to solve the above-mentioned problems. Summary of the Invention

[0005] The object of the present invention is to provide a self-locking multi-stage helical tooth variable diameter reamer while drilling to solve the problem that the above-mentioned drilling device cannot flexibly adjust the reaming diameter according to actual needs during the drilling process.

[0006] To achieve the above object, the present invention provides the following technical solution: a self-locking multi-stage helical tooth variable diameter reamer while drilling, comprising an upper joint, a core shaft body, a lower joint and a housing, and further comprising:

[0007] a ball pitching seat, which is arranged on a side of the core shaft body away from the upper joint and movably arranged inside the lower joint, and is used to drive the core shaft body to move between the upper joint and the lower joint under the push of drilling fluid;

[0008] A hole-reaming unit, provided on the mandrel body and passing through a movable groove provided on the housing, moves along with the mandrel body and is used to adjust the hole diameter of the reamer;

[0009] The control unit is arranged on the core shaft body and located inside the shell, and is used to fix the reaming unit after the diameter change is completed.

[0010] Wherein, the hole expansion unit comprises:

[0011] An adjustment component is arranged at an equal angle on the core shaft body and connected to the blade provided on the housing, and is used to adjust the extension length of the blade on the housing;

[0012] The first elastic member is arranged on a side of the adjustment component close to the control unit and abuts against the second limiting ring on the core shaft body.

[0013] Wherein, the adjustment component includes:

[0014] A push block is provided on the core shaft body and is located on a side of the blade close to the upper joint, and is used to push the blade to expand toward the outside of the shell under the push of the core shaft body;

[0015] The pulling block is arranged on the core shaft body and is located on the side of the blade close to the lower joint and is internally abutted against the first limiting ring arranged on the core shaft body, and is used for pulling the blade to retract toward the inside of the shell under the push of drilling fluid.

[0016] Wherein, the adjustment component further includes:

[0017] A guide rail is arranged on one side where the push block and the pull block are connected to the blade wing and is slidably arranged in the guide groove on the blade wing.

[0018] Wherein, the control unit includes:

[0019] a limiting assembly, disposed on the housing and threadedly connected to the upper joint;

[0020] A guide assembly, disposed inside the limit assembly, for limiting the telescopic travel of the blade;

[0021] A propulsion assembly, disposed on the core shaft body and movably connected to the interior of the guide assembly, for transmitting the thrust generated by the drilling pressure difference on the pitching seat;

[0022] A control assembly is sleeved on the spindle body and cooperates with the propulsion assembly to convert the axial movement of the spindle body into rotational movement, and is used to control the state switching of the blade wing between "extending and locking" and "retracting and unlocking";

[0023] The second elastic member is sleeved on the core shaft body and located between the control assembly and the push block, and is used for providing a restoring force for the blade.

[0024] Wherein, the limiting component includes:

[0025] a fixed shell, which is threadedly connected to the upper joint and has a positioning block on the outer side thereof that cooperates with the shell;

[0026] A fixing ring is arranged on a side of the fixing shell away from the upper joint and is connected to the control component, and is used to limit the control component after adjustment.

[0027] Wherein, the guide assembly includes:

[0028] a guide ring, disposed inside the fixed shell and fixedly connected to the fixed shell via a positioning bar;

[0029] A guide bevel ring, arranged on a side of the guide ring away from the upper joint;

[0030] The guide bevel teeth are arranged on the guide bevel ring and are used to guide the rotation of the control component.

[0031] Wherein, the propulsion assembly comprises:

[0032] a propulsion ring fixed to the mandrel body and moving laterally with the mandrel body;

[0033] A limit block is provided on the propulsion ring at equal angles and is slidably connected to a slide groove provided on the guide ring;

[0034] A positioning groove is provided on the propulsion ring at an equal angle and cooperates with the control assembly for positioning the control assembly.

[0035] Wherein, the control component includes:

[0036] a control ring, sleeved on the core shaft body and abutting against a third limiting ring on the core shaft body;

[0037] A guide bar is provided on one side of the control ring close to the guide bevel teeth and is plugged and fixed to the positioning groove and adjusts the extension length of the blade under the push of the propulsion ring;

[0038] The locking protrusions are arranged at equal angles on the guide strip and connected to the fixing ring, and are used to fix the control ring after adjustment.

[0039] Among them, the fixing ring is provided with a first limiting groove, a second limiting groove and a third limiting groove; the guide bevel teeth are provided with a first tooth groove, a second tooth groove and a third tooth groove corresponding to the positions of the first limiting groove, the second limiting groove and the third limiting groove, and the locking protrusions are respectively clamped in the first limiting groove, the second limiting groove and the third limiting groove.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The present invention is implemented through the structure of the control unit. When the reaming blade needs to change diameter, the pressure differential force formed at the ball seat continuously changes due to the change in drilling fluid flow rate. That is, the ball seat at the lower part of the mandrel body is affected by the pressure of the drilling fluid, converting the drilling fluid pressure into thrust. The ball seat cooperates with the control unit in the reamer to reduce the flow rate after a certain period of time. The control unit can lock the blade, thereby completing the multi-stage diameter change of the blade.

[0042] 2. The present invention is able to realize three-level reaming in the well by designing a helical-tooth multi-level control mechanism, significantly reducing the difficulty of reaming, and integrating the blade wing reaming locking and autonomous reverse release functions: by designing a convex groove rotation locking mechanism and a pressure-holding reverse downward release structure, while realizing multi-functional integration, it effectively avoids the conflict between the locking and release in the up and down strokes. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of the main structure of an embodiment of the present invention;

[0044] Figure 2 This is a schematic diagram of the structure of blade adjustment in one embodiment of the present invention;

[0045] Figure 3 This is a schematic side view of the structure of one embodiment of the present invention;

[0046] Figure 4 A schematic diagram of a partially sectional structure of an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of the external structure of an embodiment of the present invention;

[0048] Figure 6 This is a schematic diagram of the structure of the connection between the core shaft body and the adjustment assembly in one embodiment of the present invention;

[0049] Figure 7 This is a schematic structural diagram of a housing in one embodiment of the present invention;

[0050] Figure 8 Schematic diagram of the structure of the explosion of the hole expansion unit in one embodiment of the present invention;

[0051] Figure 9 A schematic structural diagram of a hole expansion mechanism in one embodiment of the present invention;

[0052] Figure 10 This is a schematic structural diagram of a control unit in one embodiment of the present invention;

[0053] Figure 11 This is a schematic diagram of the structure of the connection between the propulsion assembly and the control assembly in one embodiment of the present invention;

[0054] Figure 12This is a schematic diagram of the structure of the connection of control unit components in one embodiment of the present invention;

[0055] Figure 13 This is a schematic structural diagram of a core shaft body according to an embodiment of the present invention;

[0056] Figure 14 This is a schematic diagram of the structure of the blade when it is unblocked in one embodiment of the present invention;

[0057] Figure 15 This is a schematic structural diagram of a position limiting assembly in one embodiment of the present invention;

[0058] Figure 16 This is a schematic structural diagram of a guide assembly in one embodiment of the present invention;

[0059] Figure 17 This is a schematic structural diagram of a propulsion assembly in one embodiment of the present invention;

[0060] Figure 18 This is a schematic diagram of the structure of a control component in one embodiment of the present invention;

[0061] Figure 19 Schematic diagram of the structure of the propulsion component and the movement direction of the control component in one embodiment of the present invention.

[0062] In the figure: 1, shell; 101, movable groove; 2, spindle body; 21, upper spindle; 22, middle spindle; 23, lower spindle; 24, first limiting ring; 25, second limiting ring; 26, third limiting ring; 3, lower joint; 4, reaming unit; 41, push block; 4101, slot; 42, pull block; 43, guide rail; 44, fixing pin; 45, blade; 4501, guide groove; 46, first elastic member; 5, control unit; 51, limiting assembly; 511, fixed shell; 512, fixing ring; 51201, first limiting groove; 51202, second Limiting groove; 51203, third limiting groove; 513, positioning block; 52, guide assembly; 521, guide ring; 522, positioning strip; 52201, slide groove; 523, guide bevel ring; 52301, first tooth groove; 52302, second tooth groove; 52303, third tooth groove; 524, guide bevel tooth; 53, propulsion assembly; 531, propulsion ring; 532, limiting block; 533, positioning groove; 54, control assembly; 541, control ring; 542, guide strip; 543, locking protrusion; 55, second elastic member; 6, pitching seat; 7, upper joint. DETAILED DESCRIPTION

[0063] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0064] Example 1

[0065] See also Figure 1-19 The present invention provides a technical solution: a self-locking multi-stage helical tooth variable diameter reamer while drilling, comprising an upper joint 7 fixedly connected to a downhole drill string, a core shaft body 2 arranged on a side of the upper joint 7 away from the downhole drill pipe for conveying drilling fluid, a lower joint 3 arranged on a side of the core shaft body 2 away from the upper joint 7, and a shell 1 sleeved on the core shaft body 2 and located between the upper joint 7 and the lower joint 3 for protecting the core shaft body 2, and further comprising: a ball pitching seat 6, which is arranged on a side of the core shaft body 2 away from the upper joint 7 and movably arranged on the lower joint 3 , and is used to drive the core shaft body 2 to move between the upper joint 7 and the lower joint 3 under the push of the drilling fluid; the reaming unit 4 is provided on the core shaft body 2 and penetrates the movable groove 101 provided on the shell 1, and moves with the core shaft body 2 to adjust the reaming diameter of the reamer; the control unit 5 is provided on the core shaft body 2 and is located inside the shell 1, and is used to fix the reaming unit 4 after the diameter change is completed. The core shaft body 2 consists of an upper core shaft 21, a middle core shaft 22 and a lower core shaft 23, and the middle part is hollow.

[0066] It should be noted that, during operation, when the blade 45 can be normally extended and retracted in multiple stages, when the borehole diameter of the reaming unit 4 is adjusted, after the reamer moves to the well section where reaming is required, the drilling fluid flow rate is increased to the set threshold value and maintained for a certain period of time. During this period, the pressure differential force generated by the drilling fluid flow rate at the ball seat 6 increases. After the pressure differential force is greater than the supporting force of the control unit 5, the core shaft body 2 will follow the ball seat 6 downward and compress the control unit 5 and the reaming unit 4, and the blade 45 is extended from the inside of the shell 1; when the reaming blade 45 needs to be retracted, by increasing the drilling fluid flow rate to the set threshold value, the pressure differential force increases, causing the reaming unit 4 to follow the ball seat 6 downward and compress the control unit 5 and the reaming unit 4. The ball seat 6 moves downward and separates from the control unit 5, reducing the flow rate after a certain period of time, and then the control unit 5 drives the blade 45 to reset, so that it returns to the initial retracted position of the blade 45. The multi-stage diameter change of the blade 45 can be achieved through the structure of the control unit 5. When the reaming blade 45 needs to change its diameter, the pressure difference force formed at the ball seat 6 changes continuously due to the change in the drilling fluid flow rate, that is, the ball seat 6 at the lower part of the core shaft body 2 is affected by the pressure of the drilling fluid, and the drilling fluid pressure is converted into thrust, which cooperates with the control unit 5 in the reamer to reduce the flow rate after a certain period of time. The control unit 5 can lock the blade 45, thereby completing the multi-stage diameter change of the blade 45.

[0067] In one embodiment, the reaming unit 4 includes: an adjustment component, which is arranged at an equal angle on the core shaft body 2 and connected to the blade wing 45 provided on the shell 1, for adjusting the extension length of the blade wing 45 on the shell 1; a first elastic member 46, which is arranged on the side of the adjustment component close to the control unit 5 and abuts against the second limiting ring 25 on the core shaft body 2.

[0068] This design, see Figure 8 ,as well as Figure 9 When the core shaft body 2 moves downward in the shell 1, the blade wing 45 will be pushed to the side away from the core shaft body 2 through the adjustment component and then extend from the movable groove 101 opened on the shell 1 to complete the drilling reaming work, and the second limiting ring 25 can limit the stroke of the control unit 5 and the moving distance of the push block 41 to prevent the blade wing 45 from falling off the guide rail 43, that is, the blade wing 45 extends outward to the maximum point. Due to the action of the third limiting ring 26, the push block 41 no longer pushes the blade wing 45. Subsequently, the middle core shaft 22 moves downward, and the second limiting ring 25 compresses the first elastic member 46 for buffering until the control mechanism ends its downward movement, thereby controlling the maximum displacement of the control unit 5 to prevent the blade wing 45 from falling off the adjustment component. The outer diameter of the first elastic member 46 buffer sleeve is 80mm, and it slides with the shell 1. A step is provided at the place where the first elastic member 46 is installed. The upper surface of the internal step provides support for the first elastic member 46 and slides with the core shaft body 2. The lower end of the internal step is provided with a thread connected to the push block 41.

[0069] In one embodiment, the adjustment component includes: a push block 41, which is arranged on the core shaft body 2 and is located on the side of the blade wing 45 close to the upper joint 7, and is used to push the blade wing 45 to expand toward the outside of the shell 1 under the push of the core shaft body 2. Under normal working conditions, under the interaction of the core shaft body 2 and the first elastic member 46, the push block 41 can pull the blade wing 45 for recovery; a pull block 42, which is arranged on the core shaft body 2 and is located on the side of the blade wing 45 close to the lower joint 3 and is internally abutted against the first limiting ring 24 provided on the core shaft body 2, and is used to pull the blade wing 45 toward the inside of the shell 1 under the push of drilling fluid when the blade wing 45 is stuck and the push block 41 cannot be recovered normally. A slot 4101 for fixing the guide rail 43 is provided on both the push block 41 and the pull block 42.

[0070] This design, see Figure 1-4 ,as well as Figure 8 When it is necessary to adjust the length of the blade 45 extending out of the shell 1, the drilling fluid flow is increased to the set threshold value and the reamer is moved to the well section where the hole needs to be reamed and maintained for a certain period of time. During this period, the pressure difference force generated by the drilling fluid flow at the ball seat 6 increases. When the pressure is greater than the set value, the core shaft body 2 will be pushed axially inside the shell 1, thereby driving the push block 41 to push the side close to the pull block 42, and then the blade 45 will slide outward from the push block 41 and the pull block 42, thereby extending outward from the inside of the shell 1, changing the drilling diameter of the blade 45, and then reaming the well wall after drilling. The extension distance of the blade 45 can be changed by changing the pressure of the drilling fluid on the ball seat 6, thereby meeting the multi-level adjustment of the reaming diameter.

[0071] The pressure drop calculation formula generated at the diameter change of the inclined surface of the pitching seat 6 is:

[0072]

[0073] in, Indicates the voltage drop, represents the local resistance coefficient, and ,in represents the flow velocity of the fluid before the slope, where Indicates the flow rate of the fluid behind the inclined plane, represents the drilling fluid density, Indicates the average flow rate of the liquid.

[0074] The calculation formula for the thrust generated by the pressure drop of the drilling fluid on the pressure-bearing surface of the ball-dropping seat 6 is:

[0075]

[0076] in, Indicates the thrust generated by the pressure-bearing surface of the pitching seat 6, Indicates the pressure drop generated at the inclined diameter change point, Indicates the major diameter of the pressure-bearing surface of the pitching seat 6, Indicates the minor diameter of the pressure surface of the pitching seat.

[0077] In one embodiment, the adjustment assembly further includes: a guide rail 43 , which is disposed on one side where the push block 41 and the pull block 42 are connected to the blade wing 45 and is slidably disposed in the guide groove 4501 on the blade wing 45 .

[0078] This design, see Figure 8 ,as well as Figure 9 The cooperation between the guide rail 43 and the guide groove 4501 provides precise guidance for the relative movement between the push block 41, the pull block 42 and the blade wing 45. When the push block 41 pushes the blade wing 45 to expand outward or the pull block 42 pulls the blade wing 45 to retract inward, the guide rail 43 can ensure that the blade wing 45 moves along a predetermined straight line trajectory, avoiding the blade wing 45 from deflecting, shaking or tilting during movement, thereby ensuring the accuracy of the expansion and contraction position of the blade wing 45, so that the reamer can accurately control the wellbore size.

[0079] In one embodiment, the control unit 5 includes: a limit assembly 51, which is arranged on the shell 1 and threadedly connected to the upper joint 7; a guide assembly 52, which is arranged inside the limit assembly 51, for limiting the telescopic stroke of the blade 45; a propulsion assembly 53, which is arranged on the core shaft body 2 and movably connected to the inside of the guide assembly 52, for transmitting the thrust generated by the drilling pressure difference on the pitching seat 6; a control assembly 54, which is sleeved on the core shaft body 2 and cooperates with the propulsion assembly 53 to convert the axial movement of the core shaft body 2 into rotational movement, for controlling the state switching of the blade 45 between "extending and locking" and "retracting and unlocking"; a second elastic member 55, which is sleeved on the core shaft body 2 and located between the control assembly 54 and the push block 41, for providing a restoring force for the blade 45.

[0080] This design, see Figure 6-18The limiting component 51 is arranged on the shell 1 and is threadedly connected to the upper joint 7, so that the connection between the limiting component 51 and the shell 1 is more stable. The guide component 52 is located inside the limiting component 51. The cooperation of the two can provide precise guidance and strict stroke limit for the telescopic movement of the blade 45. During the telescopic process of the blade 45, the guide component 52 ensures that the blade 45 moves along a predetermined straight line trajectory. The propulsion component 53 is arranged on the core shaft body 2 and movably connected inside the guide component 52. When the thrust generated by the drilling hydraulic pressure difference on the pitching seat 6 pushes the core shaft body 2 to move, the propulsion component 53 moves axially with the core shaft body 2, and then contacts the control component 54 and pushes the control component 54 to move, so that the control component 54 is separated from the guide component 52, and at this time the second elastic member 55 will push the push block 41 in the core shaft The shaft body 2 moves axially to change the extended position of the blade 45, and under the action of the second elastic member 55, the control component 54 rotates on the core shaft body 2. When the drilling hydraulic pressure difference becomes smaller, the control component 54 moves closer to the side of the guide component 52 under the action of the second elastic member 55, and is clamped at different positions on the guide component 52, thereby changing the distance between the control component 54 and the push block 41, so that the extended length of the blade 45 is changed, ensuring that the reamer can adjust the wellbore size in time to meet the requirements of the drilling operation. The second elastic member 55 is selected from a cylindrical helical compression spring with a nominal diameter of 8 mm, a mean diameter of 65 mm, and an effective number of turns of 8.5. Its working limit load is 1794.2 N, the maximum deformation is 100 mm, and the free height is 190 mm.

[0081] In one embodiment, the limiting assembly 51 includes: a fixed shell 511, which is threadedly connected to the upper joint 7 and has a positioning block 513 on the outside that cooperates with the shell 1; a fixed ring 512, which is arranged on the side of the fixed shell 511 away from the upper joint 7 and is connected to the control assembly 54, and is used to limit the control assembly 54 after adjustment.

[0082] This design, see Figure 15 The positioning block 513 arranged on the outside of the fixed shell 511 cooperates with the shell 1. When installing the limit assembly 51, the positioning block 513 can quickly and accurately find the corresponding position with the shell 1, ensuring that the installation position of the limit assembly 51 on the shell 1 is accurate. The fixing ring 512 is arranged on the side of the fixed shell 511 away from the upper joint 7 and is connected to the control assembly 54. Its main function is to accurately limit the adjusted control assembly 54. During the drilling operation, the control assembly 54 and the second elastic member 55 are responsible for converting the axial movement of the core shaft body 2 into rotational movement to control the state switching of the blade 45 to "extend and lock" and "retract and unlock". The fixing ring 512 is like a "precise locator", which can ensure that the control assembly 54 always remains in the adjusted position during operation, and ensures that the blade 45 is automatically locked after the extension length adjustment is completed.

[0083] In one embodiment, the guide assembly 52 includes: a guide ring 521, which is arranged inside the fixed shell 511 and fixedly connected to the fixed shell 511 through a positioning bar 522; a guide bevel ring 523, which is arranged on the side of the guide ring 521 away from the upper joint 7; and a guide bevel tooth 524, which is arranged on the guide bevel ring 523 and is used to guide the rotation of the control assembly 54.

[0084] This design, see Figure 16 The guide ring 521 is arranged inside the fixed shell 511 and is fixedly connected to the fixed shell 511 through the positioning bar 522. The guidance of the subsequent blade wing 45 components provides a stable foundation, ensuring that the blade wing 45 can move along a predetermined straight line trajectory during the extension and retraction process, thereby ensuring the precise control of the wellbore size during the drilling operation. The guide bevel teeth 524 are arranged on the guide bevel ring 523 to guide the rotation of the control component 54. Its unique bevel tooth shape design can provide clear direction guidance for the rotation of the control component 54, so that the control component 54 can only rotate at a specific angle and direction. In the process of "extending and locking" the blade wing 45, the guide bevel teeth 524 can ensure that the control component 54 accurately converts the axial movement of the core shaft body 2 into rotational movement, thereby realizing precise control of the state of the blade wing 45.

[0085] In one embodiment, the propulsion assembly 53 includes: a propulsion ring 531, which is fixed on the core shaft body 2 and moves laterally with the core shaft body 2; a limit block 532, which is set at an equal angle on the propulsion ring 531 and is slidably connected to the slide groove 52201 opened on the guide ring 521; a positioning groove 533, which is opened at an equal angle on the propulsion ring 531 and cooperates with the control assembly 54 for positioning the control assembly 54.

[0086] This design, see Figure 17 The propulsion ring 531 is fixed on the core shaft body 2 and moves laterally with the core shaft body 2. When the pitching seat 6 is thrust by the drilling fluid and moves axially inside the shell 1, the core shaft body 2 performs precise axial movement according to the drilling diameter parameters and operation requirements, and the propulsion ring 531 moves synchronously therewith, providing accurate power input for the subsequent extension and retraction of the blade 45, ensuring the precise matching of the blade 45 movement with the drilling operation. The limit block 532 is set at an equal angle on the propulsion ring 531 and is slidably connected to the slide groove 52201 opened in the guide ring 521. The slide groove 52201 provides a precise track for the sliding of the limit block 532, which can limit the movement direction of the propulsion ring 531 so that it can only move along a specific axial direction, avoiding the propulsion ring 531 from deflecting or shaking during the movement. The positioning groove 533 is set at an equal angle on the propulsion ring 531 and cooperates with the control component 54 to push the control component 54 to move axially, thereby facilitating the subsequent adjustment of the extension length of the blade 45.

[0087] In one embodiment, the control component 54 includes: a control ring 541, which is sleeved on the core shaft body 2 and abuts against the third limit ring 26 on the core shaft body 2; a guide bar 542, which is arranged on the side of the control ring 541 close to the guide bevel tooth 524 and is plugged and fixed with the positioning groove 533 and adjusts the extension length of the blade 45 under the push of the propulsion ring 531; a locking protrusion 543, which is arranged at an equal angle on the guide bar 542 and is connected to the fixing ring 512, and is used to fix the control ring 541 after the adjustment is completed.

[0088] This design, see Figure 18 The control ring 541 is sleeved on the core shaft body 2 and abuts against the third limiting ring 26 on the core shaft body 2. The third limiting ring 26 provides a clear reference for the axial position of the control ring 541 on the core shaft body 2. The guide bar 542 is set on the side of the control ring 541 close to the guide bevel gear 524 and is plugged and fixed with the positioning groove 533. When the propulsion ring 531 moves laterally with the core shaft body 2, when the propulsion ring 531 moves toward the side close to the control ring 541, the guide bar 542 is plugged into the positioning groove 533, and the guide bar 542 is plugged into the guide bevel gear 524, and the positioning groove 533 is fixed. The guide bar 542 is driven out of the tooth groove of the guide bevel tooth 524, releasing the restriction of the guide bar 542 on the guide bevel ring 523, thereby facilitating the subsequent adjustment of the extension length of the blade wing 45. When the extension length of the blade wing 45 is adjusted, the thrust of the drilling fluid on the pitching seat 6 is reduced, and the second elastic member 55 pushes the control ring 541 to move toward the side close to the guide bevel tooth 524, so that the guide bar 542 is inserted and fixed at the set position on the guide bevel tooth 524, thereby achieving precise adjustment of the extension length of the blade wing 45 to meet the requirements of wellbore size for different formations and drilling processes.

[0089] In one embodiment, a first limiting groove 51201, a second limiting groove 51202 and a third limiting groove 51203 are provided on the fixing ring 512; a first tooth groove 52301, a second tooth groove 52302 and a third tooth groove 52303 corresponding to the positions of the first limiting groove 51201, the second limiting groove 51202 and the third limiting groove 51203 are provided on the guide bevel tooth 524, and the locking protrusion 543 is respectively engaged in the first limiting groove 51201, the second limiting groove 51202 and the third limiting groove 51203.

[0090] This design, see Figure 7-8 ,as well as Figure 19The first limiting groove 51201, the second limiting groove 51202 and the third limiting groove 51203 provided on the fixing ring 512, and the first limiting groove 51201, the second limiting groove 51202 and the third limiting groove 51203 provided on the guide bevel gear 524 form a set of precise guide positioning system. When the guide bar 542 is inserted into the first limiting groove 51201, the locking protrusion 543 is snap-fitted and fixed in the first limiting groove 51201. This positioning method provides a precise positioning system for the subsequent movement of the blade 45 component. An accurate foundation is laid, so that the blade 45 can move along a predetermined trajectory during the extension and retraction process, avoiding movement jamming or trajectory deviation caused by component installation position deviation, and improving the accuracy of drilling operations. The first limit groove 51201, the second limit groove 51202 and the third limit groove 51203 are provided in three groups evenly distributed on the fixed ring 512, and the groove depths are 31 mm, 21 mm and 11 mm respectively. The design of multiple groups of limit grooves and tooth grooves can facilitate the graded adjustment of the extended length of the blade 45.

[0091] Example 2

[0092] A fixing pin 44 is provided between the pull block 42 and the housing 1 , and the pull block 42 and the housing 1 are fixed by the fixing pin 44 .

[0093] See Figure 9

[0094] When the reaming blade 45 fails and cannot be retracted normally, a steel ball is dropped into the core shaft body 2, and the steel ball moves to the ball seat 6 and blocks the ball seat nozzle of the ball seat 6. When the flow channel is blocked, pressure is generated to increase the pressure. Under the action of pressure, the ball seat 6 is separated from the sleeve installed inside the lower core shaft 23, and then the fluid channel between the lower core shaft 23 and the middle core shaft 22 is opened, and the drilling fluid enters the fixed pull block 42 of the lower blade 45. As the pressure increases, when the pressure is greater than the shear force of the fixing pin 44, the drilling fluid enters the fixed pull block 42. When the cutting force is applied, the fixing pin 44 will be cut off. At this time, the pulling block 42 will move downward, increasing the distance between the pulling block 42 and the pushing block 41. Under the action of the guide rail 43, the blocked blade wing 45 will shrink and reset to the inside of the shell 1 under the action of the hydraulic pressure, completing the forced retraction of the blade. The pulling block 42 will only force the blade wing 45 to be retracted by throwing the ball when the pushing block 41 cannot normally retract the blade wing 45 and the blade wing 45 is stuck. Under normal working conditions, the pulling block 42 is fixed to the shell 1 by the fixing pin 44 and has no effect.

[0095] In addition, if there are descriptions of "first," "second," etc. in the embodiments, such descriptions are for descriptive purposes only and should not be understood as indicating or implying the relative importance of the description or implicitly indicating the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include at least one of such features.

Claims

1. A self-locking multi-stage helical tooth variable diameter drilling reamer, comprising an upper joint (7), a core shaft body (2), a lower joint (3) and a housing (1), characterized in that: Also includes: A ball pitching seat (6) is arranged on a side of the core shaft body (2) away from the upper joint (7) and is movably arranged inside the lower joint (3), and is used to drive the core shaft body (2) to move between the upper joint (7) and the lower joint (3) under the push of drilling fluid; A hole reaming unit (4) is provided on the mandrel body (2) and is inserted into a movable groove (101) provided on the housing (1), and moves along with the mandrel body (2) to adjust the hole reaming diameter of the reamer; A control unit (5) is provided on the core shaft body (2) and located inside the housing (1), and is used to fix the reaming unit (4) after the diameter change is completed.

2. The self-locking multi-stage helical tooth variable diameter reamer according to claim 1, characterized in that: The hole expansion unit (4) comprises: An adjustment component, arranged at an equal angle on the core shaft body (2) and connected to the blade (45) provided on the housing (1), for adjusting the extension length of the blade (45) on the housing (1); The first elastic member (46) is arranged on a side of the adjustment component close to the control unit (5) and abuts against the second limiting ring (25) on the core shaft body (2).

3. The self-locking multi-stage helical tooth variable diameter reamer according to claim 2, characterized in that: The adjustment component includes: A push block (41) is provided on the core shaft body (2) and is located on a side of the blade (45) close to the upper joint (7), and is used to push the blade (45) to expand toward the outside of the housing (1) under the push of the core shaft body (2); A pulling block (42) is provided on the core shaft body (2) and is located on a side of the blade (45) close to the lower joint (3) and is internally in contact with a first limiting ring (24) provided on the core shaft body (2), and is used for pulling the blade (45) to retract toward the inner side of the shell (1) under the push of drilling fluid.

4. The self-locking multi-stage helical tooth variable diameter reamer according to claim 3, characterized in that: The adjustment component also includes: The guide rail (43) is arranged on one side where the push block (41) and the pull block (42) are connected to the blade (45) and is slidably arranged in the guide groove (4501) on the blade (45).

5. The self-locking multi-stage helical tooth variable diameter reamer according to claim 3, characterized in that: The control unit (5) comprises: A limiting assembly (51), disposed on the housing (1) and threadedly connected to the upper joint (7); A guide assembly (52) is arranged inside the limiting assembly (51) and is used to limit the telescopic stroke of the blade (45); A propulsion assembly (53) is provided on the core shaft body (2) and is movably connected to the interior of the guide assembly (52), and is used to transmit the thrust generated by the drilling pressure difference on the pitching seat (6); A control assembly (54) is sleeved on the spindle body (2) and cooperates with the propulsion assembly (53) to convert the axial movement of the spindle body (2) into rotational movement, and is used to control the state switching of the blade (45) between "extending and locking" and "retracting and unlocking"; The second elastic member (55) is sleeved on the spindle body (2) and located between the control assembly (54) and the push block (41), and is used to provide a restoring force for the blade (45).

6. The self-locking multi-stage helical tooth variable diameter reamer according to claim 5, characterized in that: The limiting component (51) includes: A fixed shell (511) is threadedly connected to the upper joint (7) and has a positioning block (513) on the outside thereof that cooperates with the shell (1); A fixing ring (512) is provided on a side of the fixing shell (511) away from the upper joint (7) and is connected to the control component (54), and is used to limit the control component (54) after adjustment.

7. The self-locking multi-stage helical tooth variable diameter reamer according to claim 6, characterized in that: The guide assembly (52) includes: A guide ring (521) is arranged inside the fixed shell (511) and fixedly connected to the fixed shell (511) via a positioning strip (522); A guide bevel ring (523) is provided on a side of the guide ring (521) away from the upper joint (7); The guiding bevel teeth (524) are provided on the guiding bevel ring (523) and are used to guide the rotation of the control component (54).

8. The self-locking multi-stage helical tooth variable diameter reamer according to claim 7, characterized in that: The propulsion assembly (53) comprises: A propulsion ring (531) is fixed on the core shaft body (2) and moves laterally with the core shaft body (2); A limit block (532) is arranged at an equal angle on the propulsion ring (531) and is slidably connected to a sliding groove (52201) provided on the guide ring (521); The positioning groove (533) is provided on the propulsion ring (531) at an equal angle and cooperates with the control component (54) to position the control component (54).

9. The self-locking multi-stage helical tooth variable diameter reamer according to claim 8, characterized in that: The control component (54) includes: a control ring (541) sleeved on the core shaft body (2) and abutting against a third limiting ring (26) on the core shaft body (2); A guide bar (542) is provided on a side of the control ring (541) close to the guide bevel tooth (524), is plugged and fixed to the positioning groove (533), and adjusts the extension length of the blade (45) under the push of the propulsion ring (531); The locking protrusion (543) is arranged at an equal angle on the guide bar (542) and is connected to the fixing ring (512), and is used to fix the adjusted control ring (541).

10. The self-locking multi-stage helical tooth variable diameter reamer according to claim 9, characterized in that: The fixing ring (512) is provided with a first limiting groove (51201), a second limiting groove (51202) and a third limiting groove (51203); the guiding bevel teeth (524) are provided with a first tooth groove (52301), a second tooth groove (52302) and a third tooth groove (52303) arranged corresponding to the positions of the first limiting groove (51201), the second limiting groove (51202) and the third limiting groove (51203); the locking protrusion (543) is respectively engaged in the first limiting groove (51201), the second limiting groove (51202) and the third limiting groove (51203).

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