A new type of pectinate reamer bit structure

Abstract

A new type of valve reamer bit structure is connected with drill pipe through threaded section, which is composed of threaded section, shaft seat, cutter disc unit, cutter body unit and disc core. Cutter body unit corresponds to cutter disc unit layer by layer; under the traction of block unit of cutter disc unit, the valve of each layer of cutter body unit makes radial expansion or radial contraction movement; the magnetic control rotation operation between shaft seat and disc core low limit core block and the rotation operation between cutter disc units can form the relative dislocation between inner and outer layer of valve, so that the groove with changed depth and width is formed on the outer surface of the cutter head. The radial disintegration and radial convergence operation of block unit of cutter disc unit, the axial operation of block unit of cutter disc unit corresponding to each level of limit core block of disc core and the relative dislocation operation of inner and outer layer of valve can eliminate the problem of sticking to a certain extent by using the principles of activity, vibration, friction, scraping and variable diameter, which has high engineering practical value.

Description

Technical Field

[0001] This invention relates to a novel lobe-type reaming drill bit structure, namely a drill bit type reaming tool structure, belonging to the field of petroleum engineering drilling tool design, manufacturing and technical technology. Background Technology

[0002] Reaming technology, also known as borehole reamering, is a drilling technique that uses a freestanding reamer in conjunction with a conventional drill bit or directly with a drill bit-type reamer to enlarge the open hole size while drilling through the entire borehole, making it larger than the inner diameter of the upper casing string. This technology reduces the number of tripping operations, is highly efficient, and is widely used in deep wells, ultra-deep wells, wells with small gaps, sidetracking wells, and complex well conditions. New freestanding reamers and drill bit-type reamers, as reaming equipment for oil, gas, and unconventional oil and gas drilling, have unparalleled advantages over conventional fixed-wing reamers. The innovation and development of drilling reamers have driven the rapid development of reaming-while-drilling technology.

[0003] While independent reamers have been widely used in complex wells such as ultra-deep wells, small-diameter wells, and sidetracked wells abroad, the extension and retraction of their reamer blades are along the designed inclined or vertical plane. The retraction of the blades requires a reduction in internal tool pressure and the assistance of internal springs to provide the retraction force. Therefore, the development and research of drill bit-type reamers that integrate reaming functionality is one of the mainstream development directions for solving the problems of reamers while drilling. Summary of the Invention

[0004] Considering the operating principle and direction of movement of the traction component for drill bit diameter expansion, and in light of the stuck drill bit problem, this invention provides an anti-sticking drill bit structure with a variable cutter groove on the surface and a hole-expanding function. It can adapt well to soft, medium and heavy formations, and can effectively avoid the problem of difficult-to-guarantee diameter reduction recovery caused by bottom hole pressure.

[0005] The technical solution adopted by this invention to solve its technical problem is:

[0006] A drill bit with an anti-jamming function is installed at the drill pipe head. This drill bit structure includes a threaded section, a shaft seat, a multi-stage cutterhead composed of inner and outer cutterhead units, a cutter head composed of inner and outer multi-stage cutter body units, and a multi-stage disc core. The cutter body units correspond to the cutterhead units layer by layer. Under the traction of the block units of the cutterhead unit, the cutter blades of each stage of the cutter body unit undergo radial expansion or contraction movement with the multi-stage telescopic disc core located at the center of the cutterhead unit. Through the magnetically controlled rotation operation between the shaft seat and the lower limit block of the disc core, and the rotation operation of the guide rail between the cutterhead units, the inner and outer cutter blades of the inner and outer cutterhead units and cutter body units can be relatively misaligned, causing grooves of varying depth and width to form on the outer surface of the cutter head. When reaming is required during drilling, the cutterhead unit is positioned and unlocked against the limiting or lower limiting core block in the core. Under the control of the external controller, the tie rod of the shaft seat traction assembly retracts around the telescopic shaft, pulling the block unit of the cutterhead unit, along with the corresponding cutter disc, radially dissociates, and the cutterhead unit's expansion flaps are in an extended and stretched state. Under the control of the external controller, the core retracts or extends the corresponding core block according to the diameter expansion requirements. The tie rod of the shaft seat traction assembly pulls the cutterhead unit close to and corresponds to the high or middle limiting core block of the core, and the cutterhead unit is positioned and locked with the high or middle limiting core block of the core, thus completing the cutterhead diameter expansion operation. When the drill bit needs to be reduced in diameter after reaming, drilling fluid is used to flush the expansion flaps of the cutterhead unit, while the reverse reaming control operation process is performed, and the expansion flaps of the cutterhead unit are in a compressed and retracted state. During the diameter reduction process, the direction of gravity is consistent with the core block conversion direction, which is more conducive to the radial retraction of the block unit's moving cutterhead unit, thus completing the cutterhead diameter reduction operation. The radial dissociation and radial retraction of the cutterhead unit blocks, the axial movement of the corresponding limit blocks of each level of the cutterhead unit blocks, and the relative misalignment of the inner and outer cutter blades utilize the principles of movement, vibration, friction, scraping, and diameter change to eliminate problems such as stuck drill bits due to sand accumulation, stuck drill bits due to well collapse, stuck drill bits due to falling objects, stuck drill bits due to sand bridges, and stuck drill bits due to mud, thus achieving effective unblocking.

[0007] The aforementioned threaded section is a circular cylindrical body with a hollow interior and a circular shape on its vertical projection surface. One end of the threaded section's circular cylindrical body is connected to the drill rod component via a thread, while the other end is coaxially and integrally formed with the disk surface of the shaft seat facing away from the cutter head.

[0008] The aforementioned bearing consists of a bearing plate, a shaft, and a traction assembly. Both the bearing plate and the shaft are cylindrical or, depending on the control assembly requirements, an annular cylindrical shape. The hollow areas inside the cylindrical or annular shaft are used to install control elements and control lines. The cylindrical or annular bearing plate and shaft are coaxial with the threaded section. The interior of the bearing plate has uniformly distributed through-holes parallel to the central axis, which serve as channels for drilling fluid to enter the cutter head via the threaded section. The cross-section of these holes is circular, square, or irregular. The bearing plate surface facing away from the cutter head is coaxially and integrally formed with one end of the threaded section. The bearing plate surface facing the cutter head is coaxially and integrally formed with the end face of the bearing shaft facing away from the cutter head and the end face of the largest core block facing the threaded section. The column height of the shaft column is equal to the sum of the central axis height of the disk core height limit block and the central axis height of the outermost cutter body unit; along the central axis direction, there is a magnetic transfer component embedded area in the wall of the shaft column, corresponding to the multi-level core blocks of the disk core in the fully extended state, and the magnetic transfer component is equipped with conventional magnetic levitation control elements.The traction assembly consists of four sets, each set including a pull rod, a telescopic shaft, and a connecting point. The telescopic shafts are evenly distributed on the bottom circumferential sidewall of the axle seat plate. The telescopic shaft is a component composed of several circular shaft pieces that can slide radially. On the same side of the shaft piece, a groove is arranged radially from the center of the disc surface. Taking one end of the shaft piece as the starting point, this end shaft piece is designated as shaft piece 1, and its center is fixed to the bottom circumferential sidewall of the axle seat plate column. The shaft piece adjacent to shaft piece 1 is designated as shaft piece 2, and the disc core locking point at the center of shaft piece 2 is unlocked. In this state, the shaft acts as a mover, sliding within the groove of shaft 1. Any disc locking point within the groove can be braked and locked under the control of an external controller. The sliding drive employs conventional electric, magnetic, and point magnetic control. The groove components, mover, and locking buckles are all standard accessories that meet structural requirements. Based on the same structure and operating principle, when the disc locking point at the center of each shaft in the assembly drives the shaft to slide a certain distance within the adjacent shaft groove, even sliding to the circumferential edge of the adjacent shaft groove, all shafts will move from their initial position... The coaxial stacked cylindrical shape transforms into a linear stacked shape extending in a single line, meaning the relative distance between the shaft pieces at both ends of the assembly is equal to the extension length of the telescopic shaft. A pull rod capable of rotating around a certain angle is located at the center of each shaft piece; the shape of the pull rod is unrestricted, and the plane containing both pull rods is parallel to the central axis of the base plate. The length of one pull rod is equal to the height of the base plate cylinder. One end of the pull rod is coaxially connected to the center of one end of the telescopic shaft shaft, and the other end is coaxially connected to the circumference of the end face of the base plate facing the threaded section. The other pull rod… One end of the rod is coaxially connected to the center of the shaft plate at the other end of the telescopic shaft, and the other end is coaxially connected to a point on the tail surface of the outermost cutter head unit. The length of the rod needs to ensure that when the shaft plate of the telescopic shaft is fully stretched and the two rods are at their maximum angle, the cutter head unit can accommodate the core block with the largest vertical projection area in the multi-level disc core. That is, it ensures that the outermost cutter head unit forms a side wrap around the largest core block in the disc core, and that the end face of the core block facing the threaded section is coplanar with the end face of the cutter head unit facing the threaded section.

[0009] The number of multi-stage cutterheads composed of the aforementioned inner and outer layer cutterhead units is greater than or equal to 2. The outermost cutterhead unit is adjacent to the bearing plate of the shaft seat. The distance between the cutterhead unit and the bearing plate of each subsequent layer increases sequentially from the outermost layer inwards, and each layer of cutterhead units forms an enclosing state from the outside inwards. Each layer of cutterhead unit consists of four block units. When the block units are closed, the overall shape is a frustum with a regular square prism through-hole at the central axis. The four prism side edges of the prism and the central axis form a coplanar shape, dividing the frustum into four blocks, i.e., four block units. Each block unit is the same size and consists of six faces. Among them, two parallel scallop-shaped planes, one large and one small, face away from and towards the threaded section, respectively; two radial planes that are roughly right-angled trapezoids with curved hypotenuses, which can be extended to intersect the central axis of the cutterhead unit; a square plane parallel to the central axis and facing the central axis; and a curved surface, i.e., a quarter-wall surface of the frustum. Four square planes form the center hole of the frustum, four arc surfaces form the entire sidewall of the frustum, four small scallop-shaped planes form a small end face of the frustum facing the threaded section, and four large fan-shaped planes form the large end face of the frustum facing away from the threaded section. The radial surfaces of two adjacent block units fit together. At the midpoint of the radial side edge of the square plane, parallel to the central axis of the cutter head unit, square expansion and contraction holes are distributed in the depth direction inside the block unit. The radial projection of these holes is square, and the radial projection of the expansion holes is similar to that of the expansion holes. The shapes remain consistent; a corrugated expansion plate is fitted between the expansion holes of two adjacent block units, with each end of the corrugated plate integrally connected to one of the two expansion holes. In the fully retracted state, the corrugated expansion plate is completely hidden within the expansion holes. When the block units of the cutter head unit disintegrate under the operation of the traction assembly, the corrugated expansion plate provides circumferential connection and allows the disintegrated block units to meet the drill bit's diameter expansion or contraction requirements, thus achieving the encapsulation of core blocks of different sizes in the multi-stage core. The height of the truncated cones of each cutter head unit along their central axis is equal; the outer arc surface of each block unit of the cutter head unit is integrally connected to the inner arc surface of the corresponding cutter body unit's blade. The radius of curvature at each point on the arc surface is consistent with the radius of curvature at each point on the corresponding cutter body unit's blade, meaning that the operation of the cutter head unit synchronously drives the operation of the cutter body unit, and vice versa.

[0010] Each block unit of the outermost cutter head unit has cylindrical positioning holes distributed from the centroid of its square plane inwards. The radial projection of these holes is circular, square, or irregular, consistent with the shape of the positioning holes at the centroid of the corresponding sidewall of the multi-level disc core. An integrated telescopic column is connected inside the positioning holes of the cutter head unit. The telescopic column can be equipped with optional conventional telescopic elements depending on structural requirements. The telescopic control system uses external electrical, magnetic, or electromagnetic control, with control elements and control lines laid inside the block unit as needed. Regardless of whether the block unit of the cutter head unit is in a dissociated radial expansion state or a retracted radial contraction state, when the square sidewall of the block unit is fully fitted with the sidewall of the multi-level disc core, the telescopic column, controlled by the external controller, extends radially inside the block unit and penetrates into the positioning holes on the sidewall of the multi-level disc core. The ends are locked by the optional locking unit, achieving the corresponding connection between the block unit of the outer cutter head unit and the disc core core.

[0011] Each block unit of the outermost cutter head unit has a magnetic levitation track assembly laid in the large scallop-shaped plane, which is concentric with the diameter of the cutter head unit when the block unit is closed. The track is circular when the block unit is closed, and the circular track is the same as the magnetic levitation track assembly laid in the small scallop-shaped plane of the block unit of the adjacent inner cutter head unit. The magnetic levitation track and control elements are selected from conventional magnetic levitation components as needed. The large scallop-shaped plane is uniformly distributed with locking holes. The radial projection of the holes is circular, square, or irregular, and the shape of the locking holes distributed in the small scallop-shaped plane of the adjacent inner cutter head unit is consistent with that of the locking holes in the small scallop-shaped plane of the adjacent inner cutter head unit. The locking holes are integrally connected with telescopic columns. The telescopic columns are equipped with conventional telescopic elements according to structural requirements. The telescopic control system adopts external electrical control, magnetic control, or electromagnetic control. The control elements and control lines are laid inside the block unit as needed. Regardless of whether the block unit of the cutter head unit is in the dissociated radial expansion state or the retracted radial contraction state, when the large scallop-shaped plane of the outer cutter head unit block unit and the small scallop-shaped plane of the adjacent inner cutter head unit block unit form an alignment hole fit, the telescopic column extends parallel to the axial direction inside the block unit of the outer cutter head unit under the control of the external controller and penetrates into the locking hole of the block unit of the adjacent inner cutter head unit. The end is locked under the operation of the additional optional locking unit, realizing the fixed connection between the outer cutter head unit and its adjacent inner cutter head unit.

[0012] When adjacent cutter head units need to rotate relative to each other, the locking components between the cutter head units are unlocked first under the control of the external controller, and the telescopic shaft inside the locking hole retracts inward. During the operation of the magnetic levitation component that is paired with the adjacent outer cutter head unit, the inner cutter head unit will drive the corresponding cutter body unit to rotate at a certain angle, and at the same time, the regular square prism hole located at its center will also rotate, and this rotation is consistent with the rotation state of the corresponding core block of the disc core around the shaft of the bearing seat.

[0013] The cutter head is not limited to a two-layer structure with only one outermost cutter head unit and one inner cutter head unit. When the number of inner cutter head unit layers is greater than or equal to 2, the structures of two adjacent inner cutter head units are respectively regarded as the outermost and innermost layers, and operate based on the same principle.

[0014] The cutter head composed of the aforementioned inner and outer layer cutter body units has the same number of cutter body unit levels as the cutter disc unit levels, that is, each cutter body unit level corresponds to one cutter disc unit level, and each cutter body unit level is composed of four petal-shaped blocks. The four petal-shaped blocks combined together form a spherical frustum with an ultra-high ring surface on the outer side wall and a hollow interior. The cutter body unit level is N, and N is greater than or equal to 2. The outermost cutter body unit is denoted as the first level, and the innermost cutter body unit is denoted as the Nth level. From the outermost first level to the innermost Nth level, the outer side wall of each level of spherical frustum-shaped cutter body unit has a raised equal-height ring along the circumference. The generatrix length of this part of the ring is consistent with the generatrix length of the arc surface of the corresponding cutter disc unit block unit. The inner side wall of the ring matches the outer side wall of the arc surface of the cutter disc unit block unit and is integrally formed and connected. In practical applications, the axial height of the first-level cutter body unit's spherical platform meets the assembly requirements and strength requirements between other components of the drill string system and the drill bit. For the second to Nth level cutter body units, the axial height of the spherical platform is equal to the difference between the axial height of the frustum of the adjacent outer-level cutter body unit and the axial height of the cutterhead unit at the same level. For the first to N-1 level cutter body units, the hollow area inside the spherical platform formed by the cutter blades is also frustum-shaped, and the radial thickness of the cutter blades, i.e., the wall thickness of the cutter blade spherical platform, meets the strength requirements during drill bit operation. For the Nth level cutter body unit, the hollow area inside the spherical platform formed by the cutter blades is cylindrical, and its cross-sectional radius is consistent with the cross-sectional radius of the shaft of the bearing seat. That is, the sidewall of the hollow area of ​​the Nth level cutter body unit forms a sidewall wrap around the shaft of the bearing seat.

[0015] The outermost first-stage cutter unit has uniformly distributed conventional teeth on its outer wall surface, which are integrally formed and connected to the cutter unit. Near the large-aperture end of the cutter unit's ball joint, a strap is laid between the inner and outer walls of the cutter unit. This strap includes a tube, a core, a telescopic section, a locking assembly, and teeth. There is one tube, composed of four hollow tube units with equal radii of curvature and arc length. This tube serves as a separation layer between the core, telescopic section, locking assembly, teeth, and the cutter unit. The projection of the tube perpendicular to the cutter unit's axis is circular. The cross-section of the tube is either circular or irregularly shaped, consisting of parallel double brackets and parallel straight lines, with the parallel double brackets parallel to the arc surfaces of the inner and outer walls of the cutter unit. The core and telescopic section are concentric circles and exist within the hollow area of ​​the tube. The cross-sectional shapes of the core and expansion joints are similar to those of the tube, and are arranged in descending order of cross-sectional area as the tube, expansion joint, and core. The core is also composed of four hollow core units with equal radii of curvature and arc length, and the four core unit joints of the core correspond radially to the four tube unit joints of the tube. There are four expansion joints with equal radii of curvature and arc length, and they are hollow. The center of each expansion joint is located at one of the four core unit joints. The geometric center of the cross-section of the expansion joint corresponds to the geometric center of the cross-section of the core and tube at the corresponding positions. The core is a common point; the expansion joint wraps around the outer surface of the core unit joint and is evenly distributed around the core diameter at equal arc length intervals. The inner wall surfaces at both ends of the expansion joint have equally spaced grooves that match the locking points on the outer wall surfaces of the core unit ends. That is, when two adjacent core units are stretched and separated along the arc direction, the expansion joint wrapped around the core unit joint, as a connecting section between the two adjacent core sections, will fill the blank section that appears when the core is separated. The outer wall surface of the expansion joint is evenly distributed with teeth and has a diamond coating to reduce the abrasive effect of downhole cuttings on the core of the belt.The extension or retraction of the telescopic section, as well as the assembly of the locking points and slots, are all controlled by an external controller. When the cutter head wraps around the lower limit core block of the disc core, the blades of the cutter head are aligned and fitted together, and the adjacent core units are aligned and fitted together. The slots on the inner wall of the telescopic section near the midpoint are aligned and locked with the locking points at the joints of the two adjacent core segments being wrapped. In this state, the telescopic section does not extend the core, and the cutter head, cutter head, core, and tube are all in a retracted state. When the cutter head wraps around the non-lower limit core block of the disc core, the blades of the cutter body unit will be synchronously disassembled as the block unit of the cutter head unit disassembles. The adjacent core units are stretched in opposite directions along their respective circumferences. The slots on the inner wall of the telescopic section, not near the midpoint, function and assemble with the locking points at the joints of the two adjacent core sections. In this state, the telescopic section extends the circumference of the core. At this time, the cutter head, cutter, core, and tube are all in a disassembled state of the constituent units. With the slots of the telescopic section assembled and locked, the outermost first-level cutter body unit is secured. When the cutter head wraps the high-limit core block of the core, the slots near both ends of the telescopic section function, and the extension of the core circumference by the telescopic section reaches its maximum value. The distance between the slots at the two ends of the telescopic section is equal to the maximum dimension of the cutter head diameter expansion, and the ends of the telescopic section are always inside the tube. An additional plug is installed between the outer wall of the telescopic section end and the inner wall of the tubing to prevent external rock cuttings from entering the tubing. At the same time, the separation of the cutterhead unit block and the cutter body unit blades helps the drilling fluid to scour the outer wall of the telescopic section, further ensuring the smooth operation of the telescopic section from the joint end of the adjacent two tubing units to the exposed or concealed retraction operation.

[0016] The aforementioned multi-stage core is a drill bit component assembled from multiple limiting core blocks using optional telescopic components. Each limiting core block is a polygonal prism, with the prisms coaxial and having the same height. When each core block is fully extended, they are arranged in descending order of cross-sectional area perpendicular to the axis, with the core block having the largest cross-sectional area facing the threaded section and the smallest core block facing away from the threaded section. The smallest core block is a regular square prism, and its shape matches the hollow square prism hole at the central axis of each stage of the cutterhead in the fully retracted state. The other core blocks are octagonal prisms, with the length of the spaced edges in the octagonal cross-section equal to the side length of the regular square cross-section of the smallest core block. Additionally, the side length of the spaced edges is equal to the length of the separation line segment formed on the cross-section by the prism side edges of the cutterhead unit block in the disassembled state. When the cutter head and the smallest core block are fully fitted together, the drill bit is at its minimum drill diameter; when the cutter head and the largest core block are fully fitted together, the drill bit is at its maximum drill diameter; when the drill bit is fully fitted together with a core block that is neither the largest nor the smallest, the drill bit is at a size between the maximum and minimum drill diameter.

[0017] Each level of the core block in the disc core has a cylindrical positioning hole distributed along the depth direction at the centroid of the four spaced sidewalls that share the same side with the smallest core block in the disc core. The cross-sectional shape of the hole is circular, square, or irregular, and it is consistent with the shape of the positioning hole at the centroid of the square plane of the block unit of the outermost cutter disc unit of the multi-level cutter disc. Furthermore, the corresponding connection between the block unit of the outermost cutter disc unit and the core blocks of each level of the disc core is achieved through the telescopic column integrally formed and connected with the positioning hole of the cutter disc unit and the optional locking unit at the end. The smallest core block is a regular square prism with a cylindrical hollow interior. The inner wall of the cylindrical hole matches the outer wall of the cylindrical shaft of the bearing seat. Magnetic rotating components, which assemble with the shaft shaft wall, are distributed along the depth of the smallest core block's cylindrical hole. These components are equipped with conventional magnetic levitation control elements. All core blocks except the largest core block are locked in place by merging smaller core blocks into their hollow interiors. Rotation at a certain angle is achieved by assembling the magnetic rotating components inside the innermost smallest core block with the bearing seat shaft. All other core blocks are hollow, and their hollow interiors perfectly match the octagonal prisms of the adjacent smaller cross-sectional layers. When the telescopic assembly is fully retracted, all other core blocks are merged into the hollow interior of the largest core block, forming a nested configuration of multiple octagonal prisms sharing a central axis with a single square prism.

[0018] Compared with existing technologies, the drill bit structure of this invention employs a traction assembly to provide bidirectional axial and radial traction to the cutterhead. This is achieved through a fixed axial connection between the shaft seat and the largest core block of the cutterhead, a radial dynamic connection between the core block and the cutterhead, magnetic rotation between cutterhead units, and a magnetic rotation connection between the core block and the shaft seat. The drill bit's diameter expansion or contraction is realized through the extension, dissociation, or retraction of the cutterhead unit blocks and the cutter body unit's blades. The direction of gravity aligns with the core block conversion direction, further facilitating the radial retraction of the moving cutterhead unit blocks. Simultaneously, the radial movement of the cutterhead unit blocks and the cutter body unit's blades, the axial movement of the core blocks at each level, and the relative misalignment of the inner and outer blade layers, all utilize the principles of movement, vibration, friction, scraping, and diameter variation to effectively unblock the drill bit, demonstrating strong practical engineering applicability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of a flap-type reamer in the high-limit reaming state.

[0020] Figure 2 This is a schematic diagram of the bearing structure.

[0021] Figure 3 This is a schematic diagram of the telescopic shaft structure.

[0022] Figure 4 These are schematic diagrams of the outer cutter head unit structure in the low limit unexpanded state and the high limit expanded state, respectively.

[0023] Figure 5 These are schematic diagrams of the external two-blade disc unit structure in the low-limit unexpanded and high-limit expanded states, respectively.

[0024] Figure 6 This is a schematic diagram of the outer one unit and the outer two units.

[0025] Figure 7 These are schematic diagrams of the outer blade unit structure in the low-limit unexpanded and high-limit expanded states, respectively.

[0026] Figure 8 This is a magnified view of the structure at section A—the stretching section of the belt.

[0027] Figure 9 These are schematic diagrams of the external two-blade unit structure in the low-limit unexpanded and high-limit expanded states, respectively.

[0028] Figure 10 These are schematic diagrams of the disk core structure in its extended and fully retracted states, respectively.

[0029] Figure 11 These are schematic diagrams of the high, medium, and low limit core block structures.

[0030] Figure 12 This is a schematic diagram of the structure of a flap-type reamer in the low-limit, unreamed state.

[0031] Figure 13 It is an axial section of the combined structure of the outer first cutter body unit and the outer second cutter body unit.

[0032] Figure 14 This is a schematic diagram of the combined configuration of the outer first cutter head unit and the outer second cutter head unit.

[0033] Figure 15 It is a schematic diagram of the combination of disc core, cutter head and cutter head.

[0034] Figure 16 This is a schematic diagram of the disk core shape.

[0035] In the diagram: 1. Threaded section, 2. Shaft seat, 3. Outer first cutter head unit, 4. Outer second cutter head unit, 5. Outer first cutter body unit, 6. Outer second cutter body unit, 7. Disc core, 21. Seat plate, 22. Shaft, 23. Guide hole, 24. Tie rod, 25. Telescopic shaft, 26. Connecting point, 27. Magnetic rotating section, 31. Outer first unit, 32. Outer first rotating rail assembly, 33. Outer first locking assembly, 34. Outer first flap, 35. Disc positioning area, 41. Outer second unit, 42. 43. Outer second transfer rail assembly, 44. Outer second locking assembly, 51. Outer second flap expansion, 52. Outer first blade, 53. Blade tooth, 54. Strap, 65. Outer second blade, 71. High limit core block, 72. Middle limit core block, 73. Low limit core block, 74. Limiting assembly, 75. Core positioning area, 251. Slot, 252. Disc core locking point, 253. Moving locking point, 254. Shaft piece, 311. Outer first head face, 312. Outer first outer side face, 313. Outer first tail 314. Outer inner side panel, 315. Outer flap expansion hole, 316. Outer locking hole, 317. Outer positioning hole, 411. Outer head panel, 412. Outer outer side panel, 413. Outer tail panel, 414. Outer inner side panel, 415. Outer flap expansion hole, 416. Outer locking hole, 531. With tube, 532. With core, 533. Telescopic section, 534. Locking element, 535. With teeth, 711. High inner side panel, 7 12. High outer surface, 713. High head surface, 714. High tail surface, 715. High positioning hole, 716. High telescopic assembly, 721. Middle inner surface, 722. Middle outer surface, 723. Middle head surface, 724. Middle tail surface, 725. Middle positioning hole, 726. Middle telescopic assembly, 731. Low inner surface, 732. Low outer surface, 733. Low head surface, 734. Low tail surface, 735. Low positioning hole, 736. Low telescopic assembly, 737. Core magnetic transition section Detailed Implementation

[0036] In this embodiment of the invention, the drill bit with a petal-shaped reaming structure consists of a threaded section, a shaft seat, a cutter head, a cutter tip, and a core. The cutter head is mainly composed of cutter head units, the cutter tip is mainly composed of cutter body units, and the core is mainly composed of limiting core blocks.

[0037] In this embodiment of the invention, the threaded section is a hollow annular cylinder with a circular projection surface.

[0038] In this embodiment of the invention, both the seat plate and the shaft of the bearing are cylindrical, or can be configured as an annular cylinder as required by the control components. The hollow area inside the annular cylinder is used to install control elements and control lines. The cross-section of the guide hole of the seat plate is circular, square, or irregular. The column height of the shaft is equal to the sum of the height of the disk core high limit block in the direction of the central axis and the height of the outer blade unit in the direction of the central axis. Along the central axis, a magnetic transfer component pre-embedded area, i.e., a magnetic transfer section, is provided in the column wall of the shaft, corresponding to each level of the disk core in the fully extended state. The magnetic transfer component is equipped with a conventional magnetic levitation control element.

[0039] In this embodiment of the invention, the number of traction components for the shaft seat is 4 sets. In each traction component, the telescopic shaft is a component composed of several circular shaft pieces that can slide radially. The disc core locking point at the center of the shaft piece, in the unlocked state, acts as a mover and slides within the groove of the adjacent shaft piece. At any position within the groove, the disc core locking point can be braked and locked under the control of an external controller. The sliding drive adopts conventional electric control, magnetic control, and point magnetic control. The groove element, the mover of the disc core locking point, and the locking buckle of the moving locking point are selected with conventional accessories that meet the structural requirements. The shape of the pull rod is not limited, and the number is 2. The plane of the two pull rods is parallel to the central axis of the base plate. The length of one pull rod is equal to the height of the column of the base plate. The length of the other pull rod needs to ensure that when the telescopic shaft piece is fully stretched and the two pull rods are at their maximum angle, the cutter head unit block can accommodate the high limit core block of the disc core. That is, it ensures that the outer cutter head unit surrounds and wraps the high limit core block, and that the end face of the core block facing the threaded section is coplanar with the end face of the cutter head unit facing the threaded section.

[0040] In this embodiment of the invention, the number of cutter head unit stages is greater than or equal to 2. Each cutter head unit stage consists of four block units. When the block unit is in its folded state, it is a frustum with a through hole of a regular square prism at its central axis. The four prism side edges of the prism form a coplanar plane with the central axis, dividing the frustum into four blocks, i.e., four block units. Each block unit is the same size and consists of six faces. Among them, two parallel scallop-shaped planes, one large and one small, face away from and towards the threaded section, respectively; two radial planes that are roughly right-angled trapezoids with curved hypotenuses, which can be extended to intersect the central axis of the cutter head unit; a square plane parallel to the central axis and facing the central axis; and a curved surface, which is one-quarter side wall of the frustum. The four square planes form the regular square prism hole at the center of the frustum, the four curved surfaces form the entire side wall of the frustum, the four small scallop-shaped planes form a small end face of the frustum and face towards the threaded section, and the four large scallop-shaped planes form the large end face of the frustum and face away from the threaded section. The expansion and retraction hole of the block unit is a square, and its radial projection is square, consistent with the radial projection shape of the expansion. The height of the frustum of the cutter head unit at each level is equal or unequal along the central axis, and the radius of curvature of each point on the arc surface of the block unit at each level is consistent with the radius of curvature of each point on the blade of the corresponding cutter body unit.

[0041] In this embodiment of the invention, the outermost cutter head unit, i.e., the outermost cutter head unit, has a positioning hole whose radial projection is circular, square, or irregular, consistent with the shape of the positioning hole at the centroid of the corresponding core block sidewall of the multi-level core. The telescopic column at the positioning hole is equipped with conventional telescopic elements according to structural requirements. The telescopic control system adopts external electrical control, magnetic control, or electromagnetic control, and the control elements and control lines are laid inside the block unit as needed. The magnetic levitation track and control elements laid in the large scallop-shaped plane are all equipped with conventional magnetic levitation system components as needed. The locking hole in the large scallop-shaped plane has a radial projection that is circular, square, or irregular, consistent with the shape of the locking hole distributed in the small scallop-shaped plane of the adjacent inner cutter head unit. The telescopic column at the locking hole is equipped with conventional telescopic elements according to structural requirements. The telescopic control system adopts external electrical control, magnetic control, or electromagnetic control, and the control elements and control lines are laid inside the block unit as needed.

[0042] In this embodiment of the invention, the number of cutter body unit levels is consistent with the number of cutter head unit levels, that is, each cutter body unit level corresponds to one cutter head unit level, and each level of cutter body unit is composed of four petal-shaped blocks. The four petal-shaped blocks, when combined, form a spherical frustum with a high outer ring surface on the outer wall and a hollow interior. The number of cutter body unit levels is N, and N is greater than or equal to 2. The outermost layer is the outermost cutter body unit, and the innermost layer is the outermost Nth cutter body unit. The length of the generatrix of the outer ring surface along the circumference of the outer wall of each level of spherical frustum-shaped cutter body unit is consistent with the length of the generatrix of the arc surface of the cutter head unit block. In practical applications, the axial height of the spherical frustum of the outermost cutter body unit meets the assembly requirements and strength requirements between other components of the drill string system and the drill bit. From the outermost second cutter body unit to the outermost Nth cutter body unit, the axial height of the spherical frustum is equal to the difference between the axial height of the frustum of the cutter body unit of the adjacent outer level and the axial height of the cutter head unit of the corresponding level. From the outer N-1 cutter body unit to the outer N-1 cutter body unit, the hollow area inside the spherical platform formed by the cutter blades is also spherical. The radial thickness of the cutter blades, i.e. the wall thickness of the spherical platform, meets the strength requirements during drill bit operation. In the outer N cutter body unit, the hollow area inside the spherical platform formed by the cutter blades is cylindrical. The radius of its cross-sectional circle is consistent with the radius of the cross-sectional circle of the shaft of the bearing seat. That is, the sidewall of the hollow area of ​​the outer N cutter body unit forms a sidewall wrap around the shaft of the bearing seat.

[0043] In this embodiment of the invention, the strap of the cutter body unit includes a tube, a core, a telescopic section, a locking element, and teeth. The locking element is selected from conventional locking components as needed. There is one tube, composed of four hollow tube units with equal radii of curvature and arc length. The projection of the tube perpendicular to the axial direction of the cutter body unit is circular. The cross-sectional radius of the tube is either circular or irregularly shaped, consisting of parallel double brackets and parallel straight lines spaced apart. The parallel double brackets are parallel to the arc surfaces of the inner and outer walls of the cutter body unit, respectively. The cross-sectional shapes of the core and telescopic section are similar to those of the tube, and are arranged from largest to smallest cross-sectional area as tube, telescopic section, and core. The core also consists of four hollow core units with equal radii of curvature and arc length. There are four telescopic sections with equal radii of curvature and arc length, and they are hollow. Teeth are evenly distributed on the outer wall surface of the telescopic sections, and the surface has a diamond abrasive coating to reduce the abrasive effect of downhole cuttings on the core of the strap. An additional plug is installed between the outer wall of the telescopic section end and the inner wall of the tubing to prevent external rock cuttings from entering the tubing. At the same time, the separation of the cutterhead unit block and the cutter body unit blades helps the drilling fluid to scour the outer wall of the telescopic section, further ensuring the smooth operation of the telescopic section from the joint end of the adjacent two tubing units to the exposed or concealed retraction operation.

[0044] In this embodiment of the invention, the core is a drill bit component assembled from multiple limiting core blocks by selecting conventional telescopic components and limiting components. The telescopic components include a high telescopic component located on the surface of the high limiting core block, a medium telescopic component located on the surface of the medium limiting core block, and a low telescopic component located on the surface of the low limiting core block. The limiting components are conventional positioning and locking components. Each level of limiting core block is a polygonal prism, with the prisms coaxial and having the same height. Each level of limiting core block consists of an inner surface, an outer surface, a head surface, a tail surface, a positioning hole, and a telescopic component. When each level of core block is fully stretched along the telescopic components installed on the core block surface, they are arranged in descending order of cross-sectional area perpendicular to the axis. The smallest core block, i.e. the lowest limit core block, is a regular square prism. The shape of the prism matches the shape of the hollow square prism hole at the central axis of each level of the cutter head in the fully retracted state. All other core blocks are octagonal prisms. The length of the four sides that are spaced apart in the octagonal cross section is equal to the side length of the regular square cross section of the smallest core block. In addition, the side length of the spaced four sides is the length of the separation line segment formed on the cross section by the prism side edge of the cutter head unit block in the dissociated state.

[0045] In this embodiment of the invention, the core positioning area of ​​the disk core block is the area where the cylindrical positioning hole is located. The positioning hole includes a high positioning hole located on the side of the high limit core block, a middle positioning hole located on the side of the middle limit core block, and a low positioning hole located on the side of the low limit core block. The cross-sectional shape of the positioning hole is circular, square, or irregular, and is consistent with the shape of the positioning hole at the centroid of the square plane of the block unit of the multi-stage cutter head unit. The low limit core block of the disk core is a regular square prism with a cylindrical internal hollow area. The inner sidewall of the cylindrical hole matches the outer wall shape of the cylindrical core rod. The magnetic rotation component on the sidewall of the core magnetic rotation section of the low limit core block's cylindrical hole is equipped with a conventional magnetic levitation control element. All other core blocks at each level are internally hollow, and the hollow area completely matches the octagonal prism of the core block at the adjacent small-sized cross-sectional level.

[0046] The number of layers in the cutter head is not limited to the two-layer structure of the outer second cutter head unit and the outer first cutter head unit. When the number of layers in the internal cutter head unit is greater than or equal to 2, the structures of two adjacent inner cutter head units are respectively regarded as the outer and inner layers, and operate based on the same principle.

[0047] Embodiments of the present invention:

[0048] This is a structure of a lobed reamer drill bit that changes its drill diameter by controlling the axial and radial movement of the cutterhead via an external controller, the radial movement between the core block and the cutterhead, the magnetic rotation of the cutterhead unit driven by the rotating rail assembly between cutterhead units, and the magnetic rotation between the core block's magnetic rotating section and the shaft's magnetic rotating section. The schematic diagrams of the lobed reamer drill bit structure in its high-limit reaming state and low-limit unreaming state are shown below. Figure 1 and Figure 12 As shown, the schematic diagrams of the bearing seat and telescopic shaft structure are as follows: Figure 2 and Figure 3 As shown, the structural schematic diagrams of the outer first cutter head unit and the outer second cutter head unit in the low limit unexpanded state and the high limit expanded state, respectively, are as follows: Figure 4 and Figure 5 As shown, the structural diagrams of the outer one unit and the outer two units are as follows: Figure 6 As shown, the structural schematic diagrams of the outer first cutter body unit and the outer second cutter body unit in the low-limit un-enlarged and high-limit enlarged states, respectively, are as follows: Figure 7 and Figure 9 As shown, a partial enlarged view of the structure at section A—the stretching section of the belt—is as follows. Figure 8 As shown, schematic diagrams of the disk core structure in its extended and fully retracted states are respectively. Figure 10 As shown in the diagram, the high, medium, and low limiting core block structures are as follows: Figure 11 As shown, the axial cross-section of the combined structure of the outer first cutter body unit and the outer second cutter body unit is as follows. Figure 13 As shown in the diagram, the combined configuration of the outer first cutter head unit and the outer second cutter head unit is as follows: Figure 14As shown in the diagram, the combination of the disc core, cutter head, and cutter head is as follows: Figure 15 As shown in the diagram, the disk core shape is as follows: Figure 16As shown. From the connection end with the drill pipe component to the cutter head where the drill bit contacts the cuttings, the structure of the reaming drill bit consists of a threaded section (1), a bearing seat (2) composed of a seat plate (21) and a shaft (22), and a disc core (7) consisting of an outer cutter body unit (5) integrally connected to the outer cutter head unit (3), an outer second cutter body unit (6) integrally connected to the outer second cutter head unit (4), and a disc core (7) consisting of a high limit core block (71), a middle limit core block (72), and a low limit core block (73). Specifically, one end of the annular cylinder of the threaded section (1) is connected to the drill pipe component by a thread, and the other end is coaxially integrally formed with the disc surface of the seat plate (21) of the bearing seat (2) facing away from the cutter head. The bearing seat (2) consists of a bearing plate (21), a shaft (22), and a traction assembly. The cylindrical or annular bearing plate (21) and the shaft (22) are coaxial with the threaded section (1). The interior of the bearing plate (21) has uniformly distributed through cylindrical guide holes (23) parallel to the central axis, which are the channels for drilling fluid to enter the cutter head through the threaded section (1). The bearing plate (21) facing away from the cutter head is coaxially and integrally formed with one end of the threaded section (1). The bearing plate (21) facing the cutter head is coaxially and integrally formed with the end face of the shaft (22) of the bearing seat (2) facing away from the cutter head and the end face of the high limit core block (71) of the bearing core (7) facing the threaded section (1). The traction assembly consists of a pull rod (24), a telescopic shaft (25), and a connecting point (26). The telescopic shaft (25), which is composed of a set of shaft pieces (254), is evenly distributed on the bottom circumferential side wall of the bearing seat (21). On the same side of the shaft piece (254), a groove (251) is arranged radially from the center of the disc surface. Starting from one end of the shaft piece (254), the center of the shaft piece (254) is fixed to the bottom circumferential side wall of the bearing seat (21) column with a shaft. When the disc core locking point (252) at the center of each shaft piece (254) drives the shaft piece (254) to slide a certain distance in the groove (251) of the adjacent shaft piece (254), or even slide to the radial edge of the groove (251) of the adjacent shaft piece (254), all shaft pieces (254) 4) The initial coaxial stacked cylindrical shape will be transformed into a linear stacked shape that extends in a line. At this time, the relative distance between the two ends of the sleeve (254) is the extension length of the telescopic shaft (25). A pull rod (24) that can rotate around a certain angle is provided at the center of the two ends of the sleeve (254). One end of the pull rod (24) is coaxially connected to the center of one end of the telescopic shaft (25) sleeve (254), and the other end is coaxially connected to the circumferential connection point (26) of the end face of the seat plate (21) of the shaft seat (2) facing the threaded section (1). One end of the other pull rod (24) is coaxially connected to the center of the other end of the telescopic shaft (25) sleeve (254), and the other end is coaxially connected to the connection point (26) on the tail surface of the outer unit (31).The outer cutter head unit (3) is adjacent to the seat plate (21) of the shaft seat (2) and is located between the outer second cutter head unit (4) and the seat plate (21). The outer first cutter head unit (3) forms a wrapping state with the outer second cutter head unit (4). The cutter head unit includes an outer single unit (31) or an outer second unit (41). The radial surfaces of two adjacent units are in contact with each other. At the middle position of the column side edge of the radial surface that is close to the square plane and parallel to the central axis of the cutter head unit, there are square expansion holes distributed in the depth direction inside the unit, including the outer single expansion hole. The outer expansion holes (315) or two outer expansion holes (415) are fitted together. An expansion corrugated plate is installed between the outer expansion holes (315) or two outer expansion holes (415) of two adjacent block units. The two ends of the corrugated plate are integrally formed and connected to the two outer expansion holes (315) or two outer expansion holes (415) respectively. When the blade disc unit is running under the traction component, the expansion corrugated plate will be completely hidden in the outer expansion hole (315) or the two outer expansion holes (415). During disassembly, the corrugated plate will play a circumferential connecting role, and can enable the disassembled block units to meet the needs of drill bit diameter expansion or contraction, so as to form a wrapping of the core blocks of different sizes of the multi-stage core (7); the outer surface of the cutter head unit block unit is composed of the head face, tail face, inner side face, outer side face and radial face. The large scallop plane, small scallop plane, square plane and arc surface of the outer unit (31) are respectively the outer head face (311), outer tail face (313), outer inner side face (314) and outer... The outer side (312), the large scallop plane, small scallop plane, square plane and arc surface of the outer two units (41) are respectively the head surface (411), tail surface (413), inner side surface (414) and outer side surface (412) of the outer two units; the outer arc surface of the block unit is integrally formed and connected with the inner arc surface of the corresponding blade unit blade, that is, the operation of the blade disc unit and the blade unit is interconnected; the square plane of the block unit is connected to the outer side of the core block of the disc core (7) through the telescopic column of the positioning hole. Each outer unit (31) of the outer cutter disc unit (3) has a positioning hole (317) on its square planar centroid extending into the depth of the positioning area (35) of the outer unit (31). The hole is integrally formed with a telescopic column. Regardless of whether the outer unit (31) is in a dissociated radial expansion state or a retracted radial contraction state, when the square side wall of the outer unit (31) and the core block side wall of the multi-level disc core (7) are fully fitted, the telescopic column will extend radially from the inside of the outer unit (31) of the cutter disc and penetrate into the positioning hole of the core block side wall of the multi-level disc core (7) under the control of the external controller. The end is locked under the operation of the optional locking unit, realizing the corresponding connection between the outer unit (31) and the limiting core block of the disc core (7). The core positioning hole includes a high positioning hole (715), a medium positioning hole (725) and a low positioning hole (735). The telescopic column and the optional locking unit are the positioning components.Each outer unit (31) of the outer cutter head unit (3) has an outer locking hole (316) evenly distributed in its large scallop-shaped plane, and an extension column is integrally formed and connected inside the hole; regardless of whether the outer unit (31) of the cutter head is in the dissociated radial expansion state or the retracted radial contraction state, when the large scallop-shaped plane of the outer unit (31) and the small scallop-shaped plane of the outer second cutter head unit block form a matching hole and fit together, under the control of the external controller, the extension column will extend from the inside of the outer unit (31) in a direction parallel to the central axis and penetrate into the outer second locking hole (416), and the end is locked under the operation of the additional optional locking unit, so as to realize the fixed connection between the outer cutter head unit (3) and the outer second cutter head unit (4); the extension column and the additional optional locking unit include the outer locking assembly (33) and the outer second locking assembly (43). The outer blade unit (3) has a magnetic levitation track assembly with concentric circles around its circumference in the large scallop-shaped plane, which is the same as the outer blade unit (31) in its folded state. The tracks of the four outer blade units (31) in the folded state are circular, and the circular tracks are the same as the magnetic levitation track assembly laid in the small scallop-shaped plane of the outer second blade unit (41). The outer walls of the spherical outer blade unit (5) and the outer second blade unit (6) have raised equal-height rings along their circumference. The inner sidewall of the rings matches the outer arc surface of the blade unit block unit and is integrally formed and connected. The outer sidewall of the outer blade unit (5) has conventional teeth evenly distributed, i.e., the blade teeth (52) are integrally formed and connected with the blade unit. On the side near the large opening of the spherical end of the blade unit, a strip of material is laid between the inner and outer walls of the blade unit. The belt consists of a tube (531), a core (532), a telescopic section (533), a locking element (534), and teeth (535); the tube (531) is an isolation layer between the core (532), the telescopic section (533), the locking element (534), and the teeth (535) and the blade unit; the core (532) and the telescopic section (533) are concentric and exist in the hollow area of ​​the tube (531); the four core units of the core (532) are... The joints of the four tube units of the tube (531) are radially corresponding; the center of the expansion section (533) is located at the joints of the four core units respectively. The geometric center of the cross section of the expansion section (533) is the same as the geometric center of the cross section of the core (532) and the tube (531) at the corresponding positions. The expansion section (533) wraps around the outer surface of the core unit joint and is evenly distributed around the circumference of the core (532) at equal arc length intervals. The inner wall of the two ends of the expansion section (533) has equally spaced slots that match the locking points of the outer wall of the core unit end. That is, when two adjacent core units are stretched and separated along the arc direction, the expansion section (533) wraps around the joint of the core unit and fills the blank section that appears when the core (532) is separated. The slots of the expansion section (533) cooperate with the locking points of the core unit to form a locking piece (534).The limiting core blocks of the disc core (7) include a high limiting core block (71), a middle limiting core block (72), and a low limiting core block (73). The high limiting core block (71) faces the threaded section (1), and the low limiting core block (73) faces away from the threaded section (1). Each limiting core block has a head surface, a tail surface, an inner surface, and an outer surface. The inner surface is the side wall of the hollow area of ​​the core block. The head surface and the tail surface face away from and towards the threaded section, respectively. The outer surface is connected to the square plane of the cutter head unit block through the telescopic post of the positioning hole. The high limiting core block (71) is divided into a high head surface (713) and a high tail surface (714). The high inner surface (711) and high outer surface (712) of the middle limiting core block (72) are divided into a middle head surface (723), a middle tail surface (724), a middle inner surface (721) and a middle outer surface (722), and a low limiting core block (73) is divided into a low head surface (733), a low tail surface (734), a low inner surface (731) and a low outer surface (732). The core positioning area (75) at the centroid of the four spaced sidewalls with the same side as the smallest core block of the disk core (7) is provided with column positioning holes distributed in the longitudinal direction inside the core block, which are integrally formed and connected with the positioning holes. The telescopic column and the optional locking unit at the end realize the corresponding connection between the outer unit (31) and the core blocks at each level; the core magnetic rotating section (737) side wall of the cylindrical hole of the low limit core block (73) has magnetic rotating elements that are matched with the wall surface of the cylindrical magnetic rotating section (27) of the shaft seat (2) and the shaft rod (22) in the longitudinal direction inside the core block. The middle limit core block (72) locks itself by retracting the low limit core block (73) into its internal hollow area and using the limiting component (74). The magnetic rotating elements inside the core magnetic rotating section (737) of the low limit core block (73) and the core seat shaft rod are used to lock it. (22) The magnetic rotating elements inside the magnetic rotating section (27) are assembled to achieve a certain angle of rotation. The magnetic rotating elements of both are magnetic rotating components. When the telescopic component is in a fully retracted state, the low limit core block (73) and the middle limit core block (72) are both incorporated into the hollow area of ​​the high limit core block (71) to form a set of two-level octagonal prisms and one-level quadrangular prisms with a common central axis. The magnetic rotating elements inside the core magnetic rotating section (737) and the magnetic rotating components inside the magnetic rotating section (27) are magnetic rotating components between the low limit core block (73) of the disk core (7) and the shaft rod (22) of the bearing seat (2).

[0049] When the drill bit is in the constricted state, the middle limiting core block (72) of the core (7) is incorporated into the hollow area of ​​the middle limiting core block (72) that already exists inside the high limiting core block (71), and the low limiting core block (73) of the core (7) extends outside the high head surface (713) of the high limiting core block (71). At this time, the outer inner side surface (314) of the outer first cutter head unit (3) and the outer inner side surface (414) of the outer second cutter head unit (4) are fully fitted with the low outer side surface (732) of the low limiting core block (73) of the core (7), the radial planes between the cutter head unit blocks are fully fitted, and the cutter blades of the cutter body unit, including the mutual docking between the outer first cutter blades (51) and the mutual docking between the outer second cutter blades (61), the mutual docking between the sections of the core (532) of the outer first cutter body unit (5) and the mutual docking between the sections of the tube (531). When a diameter expansion operation is required, the first step is to select whether to perform a misalignment operation of the cutter head unit blocks based on the required groove width and diameter depth on the cutter head surface. To complete the misalignment operation, it is necessary to unlock the outer locking components (33) and the outer locking components (43) between the outer first cutter head unit (3) and the outer second cutter head unit (4), as well as the limiting components (74) between the low extension component (736) of the low limit core block (73) of the disc core (7) and the middle extension component (726) of the middle limit core block (72). The external controller is used to complete the matching of the cutter head unit rotation components, including the outer first rotation component (32) and the outer second rotation component (42). The control and the magnetic rotation assembly between the lower limit core block (73) of the disc core (7) and the shaft rod (22) of the shaft seat (2) are coordinated to achieve the radial angle deflection of the joint between the two outer units (41) and the joint between the outer unit (31). Under the linkage of the cutter head unit, the radial angle of the joint between the two outer blades (61) and the joint between the outer blade (51) is deflected. After the drill bit diameter expansion operation is completed, the two outer blades (61) are positioned in different proportions to separate the blank area between the outer blades (51), thereby changing the misalignment state, width and depth of the cutter head surface groove, so as to adjust the cutting and grinding effect of the drill bit. After the misalignment operation is determined, the outer locking assembly (33) and the outer locking assembly (43) between the outer blade unit (3) and the outer blade unit (4) are locked.The second step involves an unlocking operation. The outer blade unit (5) strap lock (534) and outer flap (34) locking assembly, the positioning assembly between the outer blade disc unit (3) and the disc core (7) low positioning hole (735), and the moving lock point (253) of the traction assembly of the shaft seat (2) are all unlocked. The second step involves a disassembly operation. The disc core lock point (252) at the center of the telescopic shaft (25) of the shaft plate (254) of the traction assembly of the shaft seat (2) is unlocked and acts as a mover to slide towards the circumferential edge in the groove (251) of its adjacent shaft plate (254). All shaft plates (254) will change from the initial coaxial stacked cylindrical shape to a straight extended row. The linear stacked shape is opened, and the angle between the two pull rods (24) is controlled by the external controller. The pull rod (24) is used as the arm to pull the outer unit (31) of the cutter head to make radial extension and axial movement in the direction of the thread section (1). The outer first expansion plate (34) and outer second expansion plate (44) in the cutter head unit and the strap (53) telescopic section (533) in the cutter body unit play a role. At the same time, under the coordinated control of the external controller between the low telescopic component (736) and the middle telescopic component (726), the low limit core block (73) of the disc core (7) is completely folded and incorporated into the hollow area of ​​the middle limit core block (72). The third step is to position the drill bit according to the required diameter expansion. Select the core block of the core (7) according to the required diameter expansion. When the shaft seat (2) traction assembly pulls the cutter head unit and cutter body unit in the disassembled state to the corresponding position of the selected core block, adjust the telescopic shaft (25), the pull rod (24) and the high telescopic assembly (716) or the middle telescopic assembly (726) of the core (7) so that the square plane of the outer unit (31) of the cutter head is in corresponding contact with the middle outer side (722) or the high outer side (712) of the selected core block. Control the positioning assembly between the outer cutter head unit (3) and the middle positioning hole (725) or the high positioning hole (715) of the core (7), the moving locking point (253) of the shaft seat (2) traction assembly, and the locking piece (534) of the outer cutter body unit (5) to complete the locking operation.

[0050] When the drill bit needs to be reduced in diameter, the three steps, the unlocking and locking nodes are the same as those for the diameter expansion adjustment. Only the diameter reduction requirement needs to be selected and operated in reverse on the component unit. During the diameter expansion and reduction operation of the drill bit, the radial separation and radial retraction of the cutter head unit block unit and the cutter body unit cutter flakes, the axial movement of the limit core blocks of each level of the cutter head unit block unit corresponding to the core (7), the relative misalignment of the inner and outer layer cutter flakes, and the scouring of the drilling fluid, by utilizing the movement, vibration, friction, scraping and diameter change principle of each component unit in the drill bit structure, it is possible to eliminate problems such as stuck drill bit due to sand, stuck drill bit due to well collapse, stuck drill bit due to falling objects, stuck drill bit due to sand bridge and stuck drill bit due to mud to a certain extent.

Claims

1. A novel petal-type reaming drill bit structure, comprising a threaded section, a bearing seat, a multi-stage cutter head unit consisting of a cutter head, inner and outer multi-stage cutter body units consisting of cutter heads, and a multi-stage limiting core block consisting of a disc core. The bearing seat consists of a base plate, a shaft, and a traction assembly. The traction assembly includes a pull rod, a telescopic shaft, and a connecting point. The cutter head unit is composed of block units, and the cutter body unit is composed of cutter petals. The outermost cutter body unit is provided with a strap. The dynamic connection component between the cutter head units is a locking component between them. The dynamic connection component between the cutter head and the disc core is a positioning component between them. The relative rotation component between the cutter head units is a rotating rail component between them and a magnetic rotation component between the lower limiting core block of the disc core and the shaft of the bearing seat. The dynamic connection component between each level of limiting core block of the disc core is a telescopic component. The dynamic connection component between the block units of the cutter head unit is an expanding corrugated plate. The dynamic connection component between the cutter petals of the outermost cutter body unit is a strap and a traction component between the bearing seat and the outermost cutter head unit. Its characteristic is: One end of the threaded section's annular cylinder is threadedly connected to the drill rod assembly, while the other end is coaxially and integrally formed with the bearing seat's face away from the cutter head. The bearing seat and shaft of the cylindrical or annular cylinder are coaxial with the threaded section. The interior of the bearing seat cylinder has uniformly distributed through-holes parallel to the central axis. The face of the bearing seat facing away from the cutter head is coaxially and integrally formed with one end of the threaded section. The face of the bearing seat facing the cutter head is coaxially and integrally formed with the end face of the bearing seat shaft facing away from the cutter head and the end face of the largest core block facing the threaded section. In the traction assembly, the telescopic shaft, composed of shaft sleeves, is evenly distributed on the bottom circumferential sidewall of the bearing seat. On the same side of the shaft sleeves, grooves are radially arranged from the center of the bearing seat. Starting from one end of the shaft sleeve, the center of the shaft sleeve is fixed to the bearing seat by the shaft. At the bottom circumferential sidewall of the base plate; at the center of the shaft pieces at both ends of the sleeve, there is a tie rod that can rotate around it by a certain angle. One end of the tie rod is coaxially connected to the center of the shaft piece at one end of the telescopic shaft, and the other end is coaxially connected to the circumferential connection point of the end face of the base plate facing the threaded section. One end of the other tie rod is coaxially connected to the center of the shaft piece at the other end of the telescopic shaft, and the other end is coaxially connected to the connection point on the tail face of the outer unit. The outermost cutter head unit is adjacent to the base plate of the shaft and is located between the cutter head unit and the base plate inwardly adjacent to it. The outermost cutter head unit forms a wrapping state with the cutter head unit inwardly adjacent to it. In the cutter head unit, the radial surfaces of two adjacent block units are in contact with each other, and the middle of the radial cylindrical edge line of the square plane parallel to the central axis of the cutter head unit is close to the square plane. The block unit has square-shaped expansion holes distributed along its depth. Between the expansion holes of two adjacent block units, expansion corrugated plates are fitted, with each end of the corrugated plate integrally formed and connected to one of the two expansion holes. When fully retracted, the expansion corrugated plates are completely hidden within the expansion holes. The outer surface of the cutter head unit block unit consists of a head face, tail face, inner face, outer face, and radial face. The arc-shaped outer wall of the block unit is integrally formed and connected to the arc-shaped inner wall of the corresponding cutter body unit's blade, meaning the cutter head unit and the cutter body unit operate in tandem. The outer wall of the frustum-shaped cutter body unit has raised, level rings along its circumference. The inner wall of these rings matches and is integrally formed with the arc-shaped outer wall of the cutter head unit block unit. The outer wall surface of the outermost cutter body unit... The blade teeth are evenly distributed and integrally formed with the blade body unit. On one side near the large opening end of the blade body unit, a strap consisting of a tube, a core, a telescopic section, a locking device, and teeth is laid between the inner and outer walls of the blade body unit. The tube, composed of tube units, is an isolation layer between the core, telescopic section, locking device, and teeth and the blade body unit. The core and telescopic section are concentric and exist in the hollow area of ​​the tube. The four core unit joint seams of the core are radially corresponding to the four tube unit joint seams of the tube. The center of the telescopic section is located at the joint seams of the four core units. The geometric center of the cross section of the telescopic section is the same as the geometric center of the cross section of the core and the tube at the corresponding position. The telescopic section wraps around the outer surface of the core unit joint seam and is evenly distributed around the core diameter at equal arc length intervals.The high-limit core block of the disc core faces the threaded section, while the low-limit core block faces away from the threaded section. Each limit core block has a head face, a tail face, an inner face, and an outer face. The inner face is the sidewall of the hollow area of ​​the core block. The head face and tail face face away from and towards the threaded section, respectively. The outer face connects with the square plane of the cutter head unit block via a telescopic post with a positioning hole.

2. According to claim 1, the novel petal-type reamer structure, the bearing plate and shaft of the bearing seat are both cylindrical or, as required by the control components, an annular cylinder. The hollow area inside the annular cylinder is used to install control elements and control lines. The cross-section of the bearing plate guide hole is circular, square, or irregular. The column height of the shaft is equal to the sum of the height of the disk core height limit block along the central axis and the height of the outer tool body unit along the central axis. Along the central axis, a magnetic rotating section is provided in the wall of the shaft column, corresponding to the multi-stage core block of the disk core in the fully extended state. The magnetic rotating component is equipped with a conventional magnetic levitation control element. The bearing seat has four traction components. The telescopic shaft of the traction component is a component composed of several circular shaft pieces that can slide radially. The disk core locking point at the center of the shaft piece slides in the groove of the adjacent shaft piece as a moving part in the unlocked state. An external controller controls the moving point at any position in the groove to be braked and locked. The sliding drive adopts conventional electronic control. Magnetic control, point magnetic control, sliding groove elements, disc core locking points, and locking buckles are selected to meet the conventional accessories required for the structure. When the disc core locking point at the center of each shaft piece drives the shaft piece to slide a certain distance along the sliding groove of the adjacent shaft piece, or even slide to the circumferential edge of the sliding groove of the adjacent shaft piece, all shaft pieces will change from the initial coaxial stacked cylindrical shape to a linear stacked shape that extends in a line. That is, at this time, the relative distance between the shaft pieces at both ends of the sleeve is the extension length of the telescopic shaft. The shape of the pull rod of the traction component is not limited, and the number is 2. The plane where the two pull rods are located is parallel to the central axis of the base plate. The length of one pull rod is equal to the height of the cylinder of the base plate. The length of the other pull rod needs to ensure that when the telescopic shaft shaft piece is fully stretched and the two pull rods are at the maximum angle, the block units of the cutter head unit can accommodate the high limit core block with the largest vertical projection area in the multi-level disc core. That is, it ensures that the outer cutter head unit surrounds and wraps the high limit core block, and makes the end face of the core block facing the threaded section coplanar with the end face of the cutter head unit facing the threaded section.

3. According to claim 1, the novel petal-type reaming drill bit structure, wherein the cutter head unit has a number of stages greater than or equal to 2, and each stage of the cutter head unit consists of four block units. When the block unit is folded, it is a frustum of a cone with a regular square prism through-hole at the central axis. The four prism side edges of the prism, coplanar with the central axis, divide the frustum into four blocks, i.e., four block units. Each block unit is the same size and consists of six faces, including two parallel scallop-shaped planes, one large and one small, facing away from and towards the threaded section, respectively. The planes facing the central axis of the cutter head unit are extended to intersect the central axis, and the hypotenuse is an arc. The outermost cutter head unit has two radial planes: a square plane parallel to the central axis and facing the central axis, and an arc surface, which is a quarter-circular side wall. The square plane of the outermost cutter head unit connects to the outer side of the core block through the telescopic column of the positioning hole. The centroid of the square plane of the unit is located in the depth direction of the unit, where the column positioning holes are integrally formed and connected to the telescopic column. Regardless of whether the outermost cutter head unit is in the dissociated radial expansion state or the retracted radial contraction state, when the square side wall of the outermost cutter head unit is completely fitted with the side wall of the multi-level core block, the external controller... Under control, the telescopic column extends radially from the innermost cutter head unit block and penetrates into the positioning holes on the side wall of the multi-level disc core block. Its end is locked by the optional locking unit, achieving a corresponding connection between the block unit and the disc core limiting block. The outer cutter head unit block unit has evenly distributed locking holes in its large scallop-shaped plane, with an integrated telescopic column connected inside each hole. Regardless of whether the outer cutter head unit block unit is in a disengaged radial expansion state or a retracted radial contraction state, when the large scallop-shaped plane of the block unit aligns with the small scallop-shaped plane of its adjacent inner cutter head unit block unit, the connection is achieved under the control of an external controller. Below, the telescopic column extends parallel to the axial direction from the inside of the outer cutter head unit block and penetrates into the locking hole of the adjacent cutter head unit block. The end is locked by the additional optional locking unit to achieve a fixed connection between the outer cutter head unit and its adjacent cutter head unit. The large scallop-shaped plane of the outer cutter head unit block is laid with a magnetic levitation track assembly that is concentric with the diameter of the cutter head unit when the block is closed. The tracks of the four outer cutter head unit blocks are circular as a whole, and the circular track is the same as the magnetic levitation track assembly laid in the small scallop-shaped plane of the adjacent cutter head unit block.

4. According to claim 1, the novel petal-type reaming drill bit structure comprises four block units in the cutter head unit. The square plane of each block unit forms a regular square prism hole, four arc surfaces form the entire sidewall of a frustum, four small scallop-shaped planes form a small end face of the frustum facing the threaded section, and four large fan-shaped planes form the large end face of the frustum facing away from the threaded section. The radial projection of the expansion and retraction hole of the block unit is square, consistent with the radial projection shape of the expansion. The height of the frustum's central axis in each level of the cutter head unit is equal, and the radius of curvature of each point on the arc surface of each block unit in each level of the cutter head unit is consistent with the radius of curvature of each point on the corresponding cutter body unit's blade. When the unit blocks of the cutter head unit disintegrate under the operation of the traction assembly, the expansion corrugated plate will play a circumferential connecting role, enabling the disintegrated unit blocks to meet the drill bit's diameter expansion or contraction requirements, thereby achieving the processing of core blocks of different sizes in multiple levels of the core. The outermost cutter head unit has a positioning hole whose radial projection is circular, square, or irregular, consistent with the positioning hole shape at the centroid of the corresponding side wall of the multi-stage disc core. The telescopic columns at the positioning holes are selected from conventional telescopic elements according to structural requirements. The telescopic control system adopts external electrical, magnetic, or electromagnetic control, and the control elements and control lines are laid inside the block unit as needed. The magnetic levitation track and control elements added to the large scallop-shaped plane of the outer cutter head unit are all selected from conventional magnetic levitation system components as needed. The locking hole of the large scallop-shaped plane has a radial projection that is circular, square, or irregular, consistent with the locking hole shape distributed in the small scallop-shaped plane of the adjacent inner cutter head unit. The telescopic columns at the locking holes are selected from conventional telescopic elements according to structural requirements. The telescopic control system adopts external electrical, magnetic, or electromagnetic control, and the control elements and control lines are laid inside the block unit as needed.

5. According to claim 1, the novel petal-shaped reaming drill bit structure, the number of cutter body unit levels is consistent with the number of cutter head unit levels, i.e., each cutter body unit level corresponds to one cutter head unit level, and each cutter body unit level is composed of four petal-shaped blocks; the four petal-shaped blocks combined together form a spherical frustum with an ultra-high annular band surface on the outer side wall and a hollow interior; the cutter body unit level is N, and N is greater than or equal to 2, with the outermost layer being the outermost cutter body unit and the innermost layer being the outermost N cutter body unit; the length of the annular band generatrix along the circumference of the outer side wall of each level of spherical frustum-shaped cutter body unit is consistent with the length of the arc surface generatrix of the cutter head unit block; in practical applications, the axial height of the spherical frustum of the outermost cutter body unit satisfies... For the assembly requirements and strength requirements between other components of the drill string system and the drill bit, from the outer second cutter body unit to the outer N cutter body unit, the axial height of the spherical platform is equal to the difference between the axial height of the frustum of the cutter body unit of the adjacent outer layer and the axial height of the cutter head unit of the same layer; from the outer first cutter body unit to the outer N-1 cutter body unit, the hollow area inside the spherical platform formed by the cutter blades is also spherical, and the radial thickness of the cutter blades, i.e., the wall thickness of the cutter blade spherical platform, meets the strength requirements during drill bit operation; in the outer N cutter body unit, the hollow area inside the spherical platform formed by the cutter blades is cylindrical, and its cross-sectional radius is consistent with the cross-sectional radius of the shaft of the bearing seat, i.e., the outer N cutter body unit forms a sidewall wrapping around the shaft of the bearing seat.

6. A novel lobe-type reaming drill bit structure according to claim 1, wherein the feed band of the cutter body unit includes a tube, a core, a telescopic section, a locking element, and a tooth, and the locking element is selected as needed from conventional locking components; the tube is one in number, composed of four hollow tube units with equal radii of curvature and equal arc lengths; the projection of the tube in the direction perpendicular to the axial direction of the cutter body unit is circular, and the cross-section of the tube is a circular or irregular shape composed of parallel double brackets and parallel straight lines, wherein the parallel double brackets are parallel to the arc surfaces of the inner and outer walls of the cutter body unit respectively; the cross-sectional shapes of the core and the telescopic section are similar to those of the tube, and are respectively tube, telescopic section, and core in descending order of cross-sectional area; the core is also composed of four hollow core units with equal radii of curvature and equal arc lengths; the telescopic section has four segments with equal radii of curvature and equal arc lengths and is hollow inside; the telescopic section has two... The inner wall of the end has equally spaced grooves that match the locking points on the outer wall of the core unit end. That is, when two adjacent core units are stretched and separated along the arc direction, the expansion section, which is wrapped around the core unit joint, will fill the gap in the core separation as a connecting section between the two adjacent core units. The grooves of the expansion section and the locking points of the core unit are locked together. The outer wall surface of the expansion section has evenly distributed teeth and a diamond coating to reduce the abrasive effect of downhole cuttings on the core of the belt. A plug is added between the outer wall of the expansion section end and the inner wall of the belt tube to shield external cuttings from entering the belt tube. At the same time, due to the separation of the cutterhead unit block and the cutter body unit blade, the drilling fluid helps to flush the outer wall of the expansion section, further ensuring the smooth extension or concealment of the expansion section from the joint end of the two adjacent tube units.

7. A novel reaming drill bit structure according to claim 1, wherein the core is a drill bit component assembled from multiple limiting core blocks by optional conventional telescopic components and limiting components. The telescopic components include a high telescopic component located on the surface of the high limiting core block, a low telescopic component located on the surface of the low limiting core block, and corresponding telescopic components located on the surfaces of other limiting core blocks at various levels; the limiting components are conventional positioning and locking components; each level of the limiting core block is a multi-faceted prism, the prisms are coaxial and have the same height, and each limiting core block consists of an inner surface, an outer surface, a head face, a tail face, a positioning hole, and a telescopic component. The components consist of a shrinking assembly; each level of core blocks is arranged in descending order of cross-sectional area when fully stretched along the telescopic assembly installed on the surface of the core block; the lowest limit core block is a regular square prism, and the shape of the prism matches the hollow square prism hole at the central axis of each level of cutter head unit in the fully retracted state; the other levels of core blocks are all octagonal prisms, and the length of the four sides that are spaced apart in the octagonal cross-section is equal to the side length of the regular square cross-section of the smallest core block. In addition, the side length of the spaced four sides is equal to the length of the separation line segment formed on the cross-section by the column side edge of the cutter head unit block unit in the dissociated state.

8. According to claim 1, the core positioning area of ​​the disc core block, i.e., the area where the cylindrical positioning hole is located, has positioning holes on the side of each limiting core block. The cross-sectional shape of the holes is circular, square, or irregular, consistent with the shape of the positioning hole at the centroid of the square plane of the outermost unit block of the multi-stage cutter head. The lower limiting core block of the disc core is a regular square prism with a cylindrical hollow area inside. The inner wall of the cylindrical hole fits against the outer wall of the cylindrical core rod of the shaft seat. The magnetic rotation component inside the magnetic rotation section of the cylindrical hole of the lower limiting core block is equipped with a conventional magnetic levitation control element. All other core blocks at each level are hollow inside, and the hollow area completely matches the octagonal prism of the core block at the adjacent small-sized cross-sectional level. The non-lower limiting core blocks of the disc core have four spaces with the same side as the lower limiting core block. At the centroid of each sidewall, a core positioning area is provided. Columnar positioning holes are distributed along the depth of the core block. Telescopic columns, integrally formed with these positioning holes, and optional locking units at the ends, connect the outermost cutter head unit's block units to the corresponding core blocks of the disc core. The cylindrical hole sidewall of the low-limit core block has magnetic rotating elements distributed along its depth, which assemble with the columnar wall of the shaft seat. Non-low-limit core blocks are locked in place by retracting the low-limit core block into its internal hollow area and using a limiting assembly. Rotation at a certain angle is achieved by assembling the magnetic rotating elements inside the core magnetic rotating section of the low-limit core block with those inside the magnetic rotating section of the core seat shaft. These magnetic rotating elements constitute the magnetic rotating assembly. When the telescopic assembly is fully retracted, the hollow area of ​​the high-limit core block sequentially incorporates other core blocks of various levels. A set of multi-level octagonal prisms and single-level quadrangular prisms forming a common central axis; magnetic rotating elements inside the core magnetic rotating section and magnetic rotating elements inside the magnetic rotating section, namely the magnetic rotating assembly between the lower limit core block of the disk core and the shaft seat.

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