A PDC drill bit having ring pack blades

Abstract

This invention relates to the field of PDC drill bit structure technology, specifically to a PDC drill bit with annular cutter wings, comprising a drill bit body, wherein at least two annular cutter wings are provided on the drill bit body, the circumferential length of the annular cutter wings is greater than or equal to three times the radial width, and the annular cutter wings include cutter wing bodies and a plurality of first cutting teeth disposed on the cutter wing bodies. By adjusting the cutter wing structure, using annular cutter wings to form an annular cutter wing structure, extending circumferentially and forming a circumferential cutting area, the scraping action of the drill bit cutting teeth on the rock is more concentrated during drilling, which is conducive to the formation of rock ridges at the bottom of the well, promoting the volumetric fracturing of the rock, reducing rock breaking energy consumption, improving the cutting effect in complex environments such as high-hardness rock formations, and making it easier for the drill bit to achieve efficient drilling. At the same time, it can also reduce the wear of PDC teeth during the cutting process, effectively improving the service life of the drill bit.

Description

Technical Field

[0001] This invention relates to the field of PDC drill bit structure technology, and specifically to a PDC drill bit with ring-shaped cutter wings. Background Technology

[0002] Drill bits are rock-breaking tools used in drilling engineering to break rocks and form wellbores. Based on their cutting elements, they are mainly classified into roller cone bits, PDC bits, impregnated diamond bits, and composite bits. PDC bits rely on high-hardness, wear-resistant, self-sharpening polycrystalline diamond composite plates (PDC teeth, cutting teeth, or simply teeth) as cutting elements to shear and break rocks. PDC bits offer high mechanical drilling speeds, long service life, and low drilling costs in soft to medium-hard formations, making them widely used in oil and gas well drilling.

[0003] In field use, due to the high aggression of PDC drill bits and the heterogeneity of rock properties in the formation, the depth of penetration of PDC drill bits into the formation cannot be accurately controlled. Sometimes, the drill bit's cutting blades directly scrape, which greatly increases the torque borne by the cutting blades and is very likely to result in the drill bit breaking. The cutting blades fall to the bottom of the well, requiring retrieval, increasing the amount of drilling work, and seriously affecting the drilling cycle and progress. Although PDC teeth have high hardness, due to limitations in impact resistance and thermal wear resistance, PDC drill bits are prone to rapid wear failure of composite plates when drilling in hard formations, highly abrasive formations, and severely heterogeneous formations (interlayers of soft and hard materials, conglomerate layers, etc.). One of the most typical failure modes is impact chipping of the diamond layer of the composite plate. The chipping of the composite plate greatly reduces the cutting efficiency and service life of the drill bit. The main reason for the chipping of the composite plate is the impact force from the rock at the bottom of the well. In addition to the impact from the heterogeneity of the rock, in many cases, the impact force borne by the cutting teeth comes from the vibration of the drill bit, especially lateral vibration and oscillation. The complex vibrations of the drill bit make the working process of the cutting teeth extremely unstable. Not only does it significantly increase the unevenness of the force, but it is also frequently subjected to impact loads, which leads to accelerated failure of the cutting teeth, shortens the life of the drill bit, and affects the drilling speed and footage of the drill bit.

[0004] Suppose the drill bit has a cutting plane passing through its axis and a point on the drill bit (called the axial plane or axial surface passing through that point). When the drill bit rotates around its own axis at zero drilling speed, the contour lines of the cutting elements intersect the cutting plane or axial surface to form an intersection line. This intersection line is the axial contour line of the cutting elements. Gathering the axial contour lines of all cutting elements together forms the bottom-hole cover map of the drill bit. In the bottom-hole cover map, an envelope curve tangent to the axial contour lines of all cutting elements can be drawn; this is called the drill bit cutting contour line. The drill bit cutting contour line reflects the basic shape characteristics of the bottom of the well drilled by the drill bit. The drill bit body contour line is the position curve of the drill bit body reflected in the bottom-hole cover map; it is an important characteristic curve of a fixed-cutting structure drill bit. The drill bit tooth distribution surface refers to the curved surface formed by rotating around the drill bit axis as the center of rotation and the drill bit body contour line as the radius of rotation, intersecting with the drill bit body.

[0005] In a drill bit with a fixed cutting structure, the contour lines of the cutting elements intersect with the cutting plane or axial plane to form an intersection line. This intersection line is the axial contour line of the cutting element. By combining the axial contour lines of all the cutting elements, a bottom-hole overlay diagram of the fixed-cutting-structure drill bit is formed. An envelope curve tangent to the axial contour lines of all the cutting elements is the cutting contour line of the fixed-cutting-structure drill bit. If the drill bit rotates around its own axis while maintaining its axial position, then for a certain blade base, the intersection line of its tooth distribution surfaces sweeps with the drill bit's central axis, forming a surface of revolution. The intersection line of this surface of revolution with the axial plane is the body contour line of the blade.

[0006] In existing technologies, the structure of PDC drill bits still has room for improvement. Current PDC drill bit structures have limitations in dealing with complex geological environments and impact loads, and should be optimized and improved to enhance their actual working performance under these conditions, ensuring the stability, reliability, and operational effectiveness of the PDC drill bit itself. Therefore, a more reasonable technical solution is needed to address the problems existing in the current technology. Summary of the Invention

[0007] This invention aims to provide a PDC drill bit with ring-shaped cutter wings. By improving the cutter wing structure on the PDC drill bit, the cutter wings are arranged circumferentially. The ring-shaped structure enhances the concentration of the cutting action of the drill bit's cutting teeth on the rock, forming a rock ridge at the bottom of the well. During drilling and cutting, this can better disrupt the rock structure, promote volumetric rock fracturing, reduce rock breaking energy consumption, improve drilling efficiency, improve drill bit stability, reduce drill bit tooth wear, and thus effectively extend the service life of the drill bit.

[0008] To achieve the above objectives, the PDC drill bit with ring-shaped blades disclosed in this invention can adopt the following solution: A PDC drill bit with annular cutter wings includes a drill bit body, on which at least two annular cutter wings are provided. The circumferential length of the annular cutter wings is greater than or equal to three times the radial width. The annular cutter wings include a cutter wing body and a plurality of first cutting teeth provided on the cutter wing body.

[0009] The aforementioned disclosed PDC drill bit features multiple annular cutter wings forming an annular cutter wing structure. During the drill bit's rotation, these spaced annular cutter wings perform cutting, concentrating and damaging the corresponding cutting positions. This facilitates the formation of rock ridges at the bottom of the well, promoting volumetric rock destruction and effectively addressing complex geological conditions with high strength and hardness. Simultaneously, the annular cutter wings maintain circumferential extension, ensuring not only high strength but also enabling cutting through multiple first cutting teeth. The resulting rock ridges enhance the drill bit's stability and reduce the likelihood of impact damage to the cutting teeth.

[0010] Furthermore, the drill bit body is provided with at least two annular cutter wings. The circumferential length of the annular cutter wings is greater than or equal to four or five times the radial width. Each annular cutter wing includes a cutter wing body and a plurality of first cutting teeth disposed on the cutter wing body. The first cutting teeth are simultaneously disposed at the front and rear ends and the middle of the cutter wing body. This can better improve the force balance of the cutting teeth and the stability of the drill bit operation, and reduce the overload failure or impact failure of the cutting teeth.

[0011] Furthermore, the blade extends circumferentially, and the first cutting teeth on the blade cut the contacting rock strata. Different tooth arrangement methods directly affect the cutting results. Here, optimization is proposed, and one feasible option is suggested: at least one location on the blade has two or more first cutting teeth; the two first cutting teeth are located at different circumferential positions, and / or, the two first cutting teeth are located at different radial positions. When the above scheme is adopted, the multiple cutting teeth on the blade at different circumferential or radial positions form complementary superpositions or complementary reinforcements through rotary cutting, jointly constituting the cutting area of ​​the annular blade.

[0012] Furthermore, the annular cutter wing itself can be entirely annular, or it can be non-annular but extend circumferentially to form annular segments, or it can be non-annular and form non-circular segments. All of these structures can improve the overall strength of the cutter wing in the circumferential tangential direction and enhance the working effect during drill bit rotation. Therefore, the structure of the annular cutter wing is not uniquely limited. Here, we optimize and propose one feasible option: the annular cutter wing includes at least one annular segment cutter wing or a quasi-annular segment cutter wing, and both the annular segment cutter wing and the quasi-annular segment cutter wing have first cutting teeth at both the front and rear ends. When a quasi-annular segment cutter wing is provided, it includes an arc-shaped quasi-annular segment cutter wing, a zigzag quasi-annular segment cutter wing, or a series of quasi-annular segment cutter wings. When adopting the above scheme, the number of cutting teeth provided on the annular segment cutter wing and the quasi-annular segment cutter wing is at least two, located at the front and rear ends respectively. More cutting teeth can be provided in the middle position of the annular segment cutter wing and the quasi-annular segment cutter wing to jointly perform cutting operations and form the drilling cutting area of ​​the drill bit.

[0013] The blade wing body can be a full ring or a complete ring protrusion, or it can be a segment of a complete ring, i.e., a ring segment protrusion. To distinguish between the two different cases of "circumferential extension" and "extension mainly in the circumferential direction (close to the circumferential direction)," "full ring / ring segment" is used to represent the former, while "quasi-full ring / quasi-ring segment" is used to represent the latter.

[0014] Furthermore, during drilling, rock fragmentation generates cuttings. These cuttings can be guided to the outside of the drill bit to avoid affecting the cutting effect of the cutting teeth. This can be achieved in various ways; here, we optimize and propose one feasible option: a chip-receiving groove is provided on the cutter wing body in front of at least one of the first cutting teeth. With this solution, the chip-receiving groove extends from the cutter wing body to the outside of the drill bit, guiding the cuttings to a designated location and preventing them from accumulating in front of the cutting teeth and affecting their cutting action.

[0015] Furthermore, when arranging annular cutter wings on the drill bit body, the distribution of the cutting areas formed by the annular cutter wings should be fully considered. The cutting areas of multiple annular cutter wings should complement and reinforce each other, thereby improving the overall drilling and cutting effect. Here, optimization is proposed, and one feasible option is suggested: the annular cutter wings are located at different radial positions on the drill bit body, with at least two annular cutter wings covering cutting areas forming an interval region, or at least two annular cutter wings covering cutting areas forming an overlapping region, or at least one annular cutter wing's cutting area being covered by the cutting area of ​​another annular cutter wing. When adopting the above scheme, if adjacent cutting areas of the annular cutter wings form an interval region, a continuous rock ridge structure will be formed during drilling and rock breaking, which can disrupt the integrity of the drilling surface and more easily cause uneven or asynchronous rock surface fracturing, thus hindering drilling. When the cutting areas of the annular cutter wings overlap, they can complement and reinforce each other. Through repeated cutting of a certain area, the cutting effect is improved, facilitating an improvement in the drill bit's rock breaking effect.

[0016] Furthermore, when the cutting areas of multiple annular blades are distributed differently, additional adjustment schemes can be adopted to enhance the drilling and cutting effect. Here, we optimize and propose one feasible option: when an interval region is formed between the cutting areas covered by two annular blades, several second cutting teeth are provided within the interval region. The height of the second cutting teeth is lower than the height of the first cutting teeth, and the height difference between the second cutting teeth and the first cutting teeth in the axial direction of the drill body is greater than or equal to 0.5. ,in The average height of the first cutting teeth on two adjacent blade bodies; when the cutting areas covered by the two annular blades overlap, the cutting areas of the two annular blades completely or partially overlap, or the longitudinal cutting positions of the two annular blades form a height difference. Using the above scheme, the second cutting teeth can cut and break the rock ridges in the interval area, ensuring overall mining and drilling efficiency; in the overlapping area formed by the cutting teeth, complete or partial overlap can strengthen the cutting, and the height difference at the longitudinal cutting position allows for continuous multiple cuts at a certain rock layer location, with the cutting depth gradually increasing, thereby improving the cutting effect and reducing the probability of cutting tooth damage.

[0017] Furthermore, the distribution of different cutting zones is influenced by the structure of the blade wings and the tooth shape and distribution of the cutting teeth. The specific factors are not unique. Here, optimization is proposed, and some feasible options are suggested: the blade wings of the two annular blades have different orientations, causing the cutting zones to be spaced out or overlapped; and / or the cutting teeth on the blade wings of the two annular blades are differentiated, causing the cutting zones to be spaced out or overlapped. When adopting the above scheme, the different orientations of the blade wings refer to the difference in the radial extension distribution of the two blade wings, resulting in the separation or intersection of the cutting zones; while the differentiated setting of cutting teeth on the blade wings refers to the different diameters or positions of the cutting teeth, resulting in different cutting profiles, ultimately causing the cutting zones of the two annular blades to be spaced out or overlapped.

[0018] Furthermore, considering that the linear velocity and wear degree vary at different radii during drill bit rotation, the tooth density in the radial region of the drill bit needs to be adjusted. Here, optimization is proposed, and one feasible option is suggested: the annular cutter wings are distributed outside the concentric circle of one-quarter radius on the drill bit body end face, or the annular cutter wings are distributed inside the concentric circle of three-quarter radius on the drill bit body end face. Adopting this scheme provides different options for personalized drill bit design to meet various drilling conditions, rock-breaking requirements, and drill bit failure characteristics, maintaining drill bit mining and tunneling efficiency while reducing PDC tooth wear.

[0019] Furthermore, when the annular cutter wings are distributed on the drill bit body, in some designs they can be intermittently or continuously arranged on the same circumference, or intermittently or continuously arranged on different circumferences. When the annular cutter wings are intermittently arranged, their position can be controlled, thereby controlling the synchronicity of rock cutting during drilling and improving the cutting effect. This effect can be achieved in various ways and is not limited to one method. Here, we optimize and propose one feasible option: the annular cutter wings are distributed on the end face of the drill bit body to form several fan-shaped cutting areas, and flow channels are formed between adjacent fan-shaped cutting areas, with water holes installed in the flow channels. When adopting the above scheme, during the rotation of the fan-shaped cutting areas, the cutting starting points of multiple annular cutter wings can be located on the same radius, thereby achieving synchronous cutting, resulting in better rock fragmentation and improving drilling and mining efficiency.

[0020] Furthermore, the design of the cutter wing body can be optimized. Besides being directly mounted on the drill bit, the cutter wing body can also be connected and fixed via an intermediate transition structure. One feasible option is proposed here: at least one cutter wing body is mounted on a cutter wing base. When cutter wing bases are continuously mounted, a groove is formed between adjacent cutter wing bases, creating a drilling fluid flow channel. With this scheme, the cutter wing base is integrally formed with the drill bit, and the cutter wing base forms a bearing surface for supporting the cutter wing body. The cutter wing body can be integrally formed with the cutter wing base. Considering the relatively small thickness of the annular cutter wing, to ensure the strength and rigidity of the annular cutter wing, while increasing the water channel depth to improve the drill bit's chip removal effect and hydraulic performance such as resistance to mud packing, one or more cutter wing bases can be provided on the drill bit body. The cutter wing base is a boss extending from the drill bit body. The boss can cover the entire radial area of ​​the drill bit or a portion of the radial area. The peripheral contour of the boss can be fan-shaped or nearly fan-shaped. There is a groove between two adjacent bosses, and drilling fluid water holes can be installed in the groove. The annular blades are mounted on the base, and the grooves of the blade base and the circumferential spacing between the blades form drilling fluid channels.

[0021] Furthermore, after setting the cutter wing base, in addition to housing the cutter wing body, the cutter wing base can also be used to install more structures, thereby improving the drilling effect of the drill bit. Here, we optimize and propose one feasible option: the second cutting tooth is located on the cutter wing base or in the groove between the cutter wing bases. When adopting the above scheme, the second cutting tooth is used to break the rock ridge formed in the interval area between two adjacent annular cutter wings, and combined with the cutting of the annular cutter wings, it forms a larger cutting surface, improving the breaking effect on the rock strata.

[0022] Furthermore, in addition to the annular cutter wings, other cutter wing structures can be combined on the drill bit body to improve the drill bit's working performance. Here, we propose an optimization and one feasible option: the drill bit body is equipped with radial cutter wings. When using the above scheme, the number of radial cutter wings can be single or multiple.

[0023] Furthermore, in some designs, the second cutting tooth is located on the radial blade.

[0024] Furthermore, when radial cutter wings are used, the radial cutter wings extend outward from the center of the drill bit. The area formed by the lateral extension of the radial wing is the cutting area. The width of the cutting area is limited by its radial extension length. Here, optimization is proposed, and one feasible option is that the width of the cutting area of ​​at least one radial cutter wing is greater than or equal to 30% of the drill bit radius. With the above scheme, there are multiple radial cutter wings, and the cutting areas of each radial cutter wing can complement each other in the radial direction, forming a complete cutting surface, while also covering the cutting surface of the annular cutter wing, thus improving the cutting effect of the drill bit.

[0025] In some designs, the relative positions of the radial and annular cutter wings are adjusted. Here, we optimize and propose feasible options: the radial and annular cutter wings are spaced apart circumferentially, or the cutting area of ​​the annular cutter wing is located outside the overall cutting area of ​​the drill bit, and the cutting area of ​​the radial cutter wing is located inside the overall cutting area of ​​the drill bit. When using the above designs, the annular cutter wing is located on the outside of the drill bit. At the same angular velocity, the linear velocity on the outside of the drill bit is greater, resulting in greater wear at the PDC teeth and making them more prone to damage. By using the annular cutter wing, wear resistance is improved, and the cutting efficiency and cutting effect are better when used in conjunction with the radial cutter wing.

[0026] Furthermore, the actual length and width extension structure of the annular blade needs to be limited to facilitate adjustment of its cutting performance. Here, an optimization is proposed, and a feasible option is suggested: In the annular blade, the width of at least one annular blade is less than or equal to 1.5 or 2 times the average diameter of the cutting teeth on that blade body; or, the width of at least one annular blade is less than or equal to 1.5 or 2 times the width of the largest non-circular profile PDC tooth on that blade body. When adopting the above scheme, the average diameter or maximum profile of the cutting teeth can be set to be greater than the width of the blade body, thereby avoiding friction between the blade body and the rock layer, allowing only the cutting teeth to cut the rock layer, thus protecting the blade body. In some schemes, the width of the blade body is equal to or greater than the diameter of some cutting teeth. In this case, it is necessary to distribute more cutting teeth in the width direction of the blade body, especially by rationally arranging the inner and outer teeth in the width direction of the blade body, so that the cutting area of ​​the cutting teeth covers the width of the blade body, thereby protecting the blade body.

[0027] Furthermore, the cutting teeth on the blade body can adopt various tooth shapes. Here, we optimize and give some of the feasible options: at least one of the first cutting teeth on the annular blade adopts a pointed cutting edge, and / or, at least one of the first cutting teeth on the annular blade adopts a full-cutting edge structure.

[0028] Furthermore, the PDC drill bit in this invention can be constructed into various drill bit types. Some feasible options are proposed here: the PDC drill bit includes a core drill bit, a dual-diameter drill bit, a tower drill bit or a dual-center drill bit, and also includes a composite drill bit with movable cutting structures such as roller cones, disc cutters, and punches.

[0029] This invention adjusts the cutter wing structure, utilizing annular cutter wings to form a ring-shaped cutter wing structure that extends circumferentially to create a circumferential cutting area. This concentrates the drill bit's cutting action on the rock within the annular cutter wing's cutting area, creating a rock ridge at the bottom of the well. This improves the cutting effect in complex environments such as high-strength, high-hardness rock formations during drilling, enabling more efficient and convenient surface breaking of rock formations, promoting volumetric rock fragmentation, reducing rock-breaking energy consumption, increasing the drill bit's attack power and rock-breaking efficiency, and making it easier to achieve the drilling objective. Simultaneously, it improves the drill bit's stability, reduces PDC tooth wear during cutting, and effectively extends the drill bit's service life. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the structure of an existing PDC drill bit.

[0032] Figure 2 This is a diagram showing the tooth distribution of an existing PDC drill bit.

[0033] Figure 3 This is a schematic diagram of the PDC drill bit's deflection operation (combined drilling, oscillation, etc.).

[0034] Figure 4 These are the dimensional parameters of the PDC teeth.

[0035] Figure 5 This is a schematic diagram of the ring-shaped blade.

[0036] Figure 6 This is a schematic diagram of a ring-shaped blade.

[0037] Figure 7This is a schematic diagram of the cutting structure for different types of interleaved ring groups.

[0038] Figure 8 This is a schematic diagram of the cutting structure for different staggered overlapping ring groups.

[0039] Figure 9 This is a schematic diagram of the cutting structure (R1=R2) of a wide-narrow composite ring assembly.

[0040] Figure 10 This is a schematic diagram of a PDC drill bit with full-ring cutter wings.

[0041] Figure 11 This is a schematic diagram of a PDC drill bit with spaced ring-shaped cutter wings (ring-shaped cutter wing structure).

[0042] Figure 12 This is a diagram showing the tooth distribution of a PDC drill bit with spaced rings.

[0043] Figure 13 This is a diagram showing the tooth layout of a spaced-ring PDC drill bit with micro-coring function.

[0044] Figure 14 This is a schematic diagram of a PDC drill bit (sector) with staggered and overlapping ring-shaped cutter wings.

[0045] Figure 15 This is a schematic diagram of a ring-type PDC drill bit (single blade) with radial blades.

[0046] Figure 16 This is a schematic diagram of a ring-type PDC drill bit with radial blades (two blades).

[0047] Figure 17 This is a schematic diagram of a PDC drill bit with radial cutter wing rings (forked, double-row toothed cutter wings).

[0048] Figure 18 This is a schematic diagram of a ring-type PDC drill bit with radial cutter wings (straight and curved cutter wings, ring wing sector, and spaced ring wing).

[0049] Figure 19 This is a schematic diagram of a PDC drill bit with ring-like ring assemblies.

[0050] Figure 20 These are schematic diagrams of two structures where the annular cutter blade extends from the drill bit body.

[0051] Figure 21 This is a schematic diagram of a PDC drill bit with a stepped bottom surface (two steps in the core).

[0052] Figure 22 For PDC drill bits with irregularly shaped teeth (three applications of flat cutting teeth).

[0053] Figure 23 Different application schemes for the first cutting tooth.

[0054] Figure 24 This is a schematic diagram of a PDC drill bit structure with a series of ring-shaped flanges.

[0055] Figure 25 This is a schematic diagram of the unequal height tooth arrangement scheme for the first cutting tooth.

[0056] Figure 26 This is a schematic diagram of the tooth arrangement method (overlay diagram) on the radial blade.

[0057] Figure 27 This is a schematic diagram (top view) of the tooth arrangement method on the radial blade.

[0058] Figure 28 This is a diagram showing the tooth distribution of a ring drill bit with a wavy profile.

[0059] Figure 29 It consists of inclined cutting teeth and annular blades with inclined teeth.

[0060] Figure 30 This is a schematic diagram of the cross-section and tooth surface profile of the annular blade.

[0061] Figure 31 This is a schematic diagram of a ring-shaped blade composite drill bit with a roller cone cutting structure.

[0062] In the above attached figures, the meanings of each label are as follows: 1. Drill bit body; 11. Drill bit connector; 12. Shackle groove; 13. Tooth-laying surface; 2. Water channel; 21. Chip trough; 22. Bottom surface of water channel; 3. Nozzle or water inlet; 31. Ring nozzle; 32. Flat and long nozzle; 4. Ring-shaped blade; 41. Ring-shaped blade body; 411. Full-ring / ring-segment blade body; 412. Quasi-full-ring / quasi-ring-segment blade body; 413. String-shaped blade body; 415. Ring blade toothed surface; 416. Ring blade side surface; 42. Cutting teeth; 421. First cutting tooth; 422. Second cutting tooth; 423. Center cutting tooth; 424. Gauge-maintaining tooth; 425. Beveled cutting tooth; 426. Diamond layer; 427. Side cutting tooth; 428. Backup cutting tooth; 43. Spacing area; 44. Covering area; 45. Blade base; 451. Bottom surface of base groove; 46. Ring blade gauge-maintaining block; 47. Impregnated diamond and other wear-resistant materials; 5. Radial blade; 51. Radial blade body; 511. Radial blade tooth placement step surface; 5111. First tooth placement step surface; 5112. Second tooth placement step surface; 52. Radial blade cutting tooth; 521. Radial blade first cutting tooth; 522. Radial blade second cutting tooth; 53. Diameter retaining block; 6. Reinforcing ribs; 7. Roller cone cutting structure; 71. Roller cone; 72. Teeth; 73. Tooth palm; 8. Drill bit cutting profile; 81. Ring wing cutting profile; 9. Rock ridge; 91. Core column; 92. Bottom bench.

[0063] English alphabet codes: h c -Working height of cutting teeth w c - Width of cutting teeth d - Diameter of PDC teeth in cylindrical matrix HW-Wellwall I b - The radial inner boundary of the ring-shaped blade (the inner boundary of the ring-shaped blade coverage area) N - Cutting tooth direction reference line (normal to the bottom contour line of the well) O b - The radial outer boundary of the ring-shaped blade (the outer boundary of the ring-shaped blade coverage area) The midpoint of the M-ring coverage area or the centerline of the cutting ring. O - Drill bit center or centerline O c -Center point of cutting teeth P - Bottom surface of the well Radial position of R-ring blade t - Width of the ring-shaped blade (distance between the inner and outer boundaries of the ring-shaped blade's coverage area, i.e., I) b To O b (distance) t h - Horizontal width of the ring-shaped blade t r - Width of the ridge t s - Width of the spacer band in the spacer group w - Length of the ring-shaped blade (circumferential direction) δ h - Height difference between the first cutting tooth and the second cutting tooth I, II, III, IV - Ring Wing Sector Numbers A, B, C - Radial blade serial numbers ①, ②, ③, ④ - The serial numbers of the ring-shaped blades within the sector (① is the outermost one, and they continue in sequence radially inward). α - The deflection angle at a certain position on the ring-shaped blade. β - The angle between the drill bit's axis and the wellbore centerline when the drill bit is deflected. γ- Normal angle at a certain position on the drill bit cutting profile θ - Diamond tooth working face bevel angle Detailed Implementation The following description, in conjunction with the accompanying drawings and specific embodiments, further illustrates this embodiment.

[0064] To address the numerous shortcomings of existing PDC drill bits, the following embodiments combine... Figures 1-31 To optimize existing technologies and use them to overcome the defects in existing technologies.

[0065] Example 1 like Figure 10 , Figure 11 As shown, this embodiment provides a PDC drill bit with annular blades, including a drill bit body 1. The drill bit body 1 is provided with at least two annular blades 4. The circumferential length of the annular blades 4 is greater than or equal to three times the radial width. The annular blades 4 include blade bodies and a plurality of first cutting teeth 421 provided on the blade bodies.

[0066] The PDC drill bit disclosed in this embodiment includes a full-ring cutter blade ( Figure 10 ) and ring-shaped blades ( Figure 11 There are two structures. The full-ring cutter blade body is a complete circular ring structure. Among multiple ring blades, there are gaps between adjacent ring blades. Therefore, the drill bit can form ring-shaped rock ridges at the bottom of the well that are easily broken by volume, thus effectively reducing the drill bit's rock-breaking energy consumption. Figure 11 In this drill bit, multiple annular blades 4 form an annular blade structure. During the drill bit's rotation, multiple annular blades 4 perform cutting, causing damage to the corresponding drilling positions. This effectively addresses complex geological conditions with high strength and hardness. Furthermore, the annular blades 4 maintain circumferential extension, ensuring not only high strength but also allowing for cutting through multiple first cutting teeth 421, improving operational convenience and reducing the likelihood of cutting tooth damage.

[0067] like Figures 5-9 As shown, the annular blade 4 disclosed in this embodiment has a circumferential length that is significantly greater than its radial width. The ratio of the circumferential length to its radial width can be as high as 4 to 5 times or even higher. The cutting teeth on the annular blade 4 are arranged along the circumference of the blade. The cutting profile, cutting area and cutting working position of each annular blade 4 can be set independently. By reasonably matching the annular blades 4, annular cutting structures with different characteristics can be formed to meet the rock breaking requirements under different drilling conditions. Compared with conventional blade PDC drill bits, it can not only effectively increase the local tooth density in the easily worn areas of the drill bit, reduce impact and extend the life of the cutting teeth, but also help reduce the rock breaking energy consumption of the drill bit, improve the attack effect of the drill bit, and thus improve the rock breaking performance of the drill bit.

[0068] The working stability of the ring-type cutter-wing PDC drill bit is significantly better than that of the conventional cutter-wing drill bit. This is due to two reasons: firstly, the support or constraint effect of the rock ridge 9 on the drill bit; and secondly, the large circumferential length of the ring blades, which results in a relatively wide contact range between the PDC teeth and the rock in the circumferential direction. This significantly weakens the polygonal effect of the drill bit during drilling, thereby effectively reducing or even avoiding lateral vibration and oscillation of the drill bit in the form of swirl, and extending the working life of the PDC teeth.

[0069] like Figures 12-13 As shown, the ring-shaped cutter-wing PDC bit easily generates bottom-hole rock ridges (9), which is beneficial for volumetric rock fracturing, resulting in larger rock cuttings than conventional PDC bits. This not only facilitates accurate determination of the lithology of the encountered formation during drilling but also improves the quality of geological logging, making it suitable for use as a dedicated exploratory well bit.

[0070] Using the PDC drill bit with ring-shaped cutter wings disclosed in this embodiment, when the drill bit operates under complex vibration conditions, especially in compound drilling and situations with significant oscillation, the wellbore size usually increases significantly. Conventional PDC drill bits often experience grooves on the cutter wings between the teeth due to incomplete coverage of the bottom of the well by the drill bit's cutting teeth, which can escalate into severe circumferential shear failure in severe cases. Furthermore, under compound drilling and significant oscillation conditions, the contact and cutting state between the drill bit's cutting teeth and the bottom rock are unstable, easily generating large dynamic loads, leading to cutting tooth fracture or diamond layer 426 breakage. One purpose of the ring-shaped cutting structure is to increase the uneven cutting in the bottom area, and the large circumferential length of the ring-shaped cutter wings helps increase the number of bearing teeth, thereby effectively reducing the cutting dynamic load. Therefore, the drill bit has strong resistance to circumferential shear and impact failure.

[0071] In this embodiment, the blade wing extends circumferentially, and the first cutting teeth 421 on the blade wing cut the contacted rock strata. Different tooth arrangement methods directly affect the cutting results. This embodiment optimizes the process and adopts one feasible option: at least one location on the blade wing is provided with two or more first cutting teeth 421; the two first cutting teeth 421 are located at different circumferential positions, and / or, the two first cutting teeth 421 are located at different radial positions. When the above scheme is adopted, the multiple cutting teeth on the blade wing at different circumferential or radial positions form complementary superpositions or complementary reinforcements through rotary cutting, jointly constituting the cutting area of ​​the annular blade wing 4.

[0072] The annular cutter wing 4 can be entirely annular, or it can be non-annular but extend circumferentially to form annular segments, or it can be non-annular and form non-circular segments. All of these structures can improve the overall strength of the cutter wing on the circumferential tangent and enhance the working effect during drill bit rotation. Therefore, the structure of the annular cutter wing 4 is not uniquely limited. This embodiment optimizes and adopts one feasible option: such as... Figure 5 , Figure 6 As shown, the annular blade 4 contains at least one annular segment blade or a near-annular segment blade, and both the annular segment blade and the near-annular segment blade have first cutting teeth 421 at their front and rear ends. When a near-annular segment blade is provided, it includes an arc-shaped near-annular segment blade, a zigzag near-annular segment blade, or a series of near-annular segment blades. When the above scheme is adopted, the number of cutting teeth provided on the annular segment blade and the near-annular segment blade is at least two, located at the front and rear ends respectively. More cutting teeth can be provided in the middle position of the annular segment blade and the near-annular segment blade to jointly perform cutting operations and form the drilling cutting area of ​​the drill bit.

[0073] exist Figure 19 The document provides a drill bit with ring-shaped cutter wings 4, which are either ring-shaped or ring-like. In Figure a, the ring-shaped cutter wings have three sectors that deflect in the same direction. In Figure b, the deflection direction of sector I is opposite to that of sector II, and sector III has no deflection.

[0074] The blade wing body can be a full ring or a complete ring protrusion, or it can be a segment of a complete ring, i.e., a ring segment protrusion. To distinguish between the two different cases of "circumferential extension" and "extension mainly in the circumferential direction (close to the circumferential direction)," "full ring / ring segment" is used to represent the former, while "quasi-full ring / quasi-ring segment" is used to represent the latter.

[0075] During drilling, rock fragmentation produces cuttings. These cuttings can be guided to the outside of the drill bit to avoid affecting the cutting performance of the cutting teeth. This can be achieved in various ways; this embodiment optimizes and adopts one feasible option: such as... Figure 10 , Figure 11 As shown, a chip-receiving groove 21 is provided on the cutter wing body in front of at least one first cutting tooth 421. When the above scheme is adopted, the chip-receiving groove 21 extends from the cutter wing body to the outside of the drill bit, which can guide rock cuttings to a designated position, thereby avoiding accumulation in front of the cutting tooth and affecting the cutting action of the cutting tooth.

[0076] Furthermore, when arranging the annular cutter wings 4 on the drill body 1, the distribution of the cutting area formed by the annular cutter wings 4 should be fully considered. The cutting areas of multiple annular cutter wings 4 should complement and reinforce each other, thereby improving the overall drilling and cutting effect. This embodiment optimizes this by adopting one feasible option: such as... Figure 7 , Figure 8 and Figure 9As shown, the annular blades 4 are located at different radial positions on the drill bit body 1. At least two annular blades 4 cover cutting areas that form an interval region 43, or at least two annular blades 4 cover cutting areas that form an overlapping region, or at least one annular blade 4's cutting area is covered by the cutting area of ​​another annular blade 4. When the above scheme is adopted, when adjacent cutting areas of the annular blades 4 form an interval region 43, a continuous rock ridge 9 structure will be formed during drilling and rock breaking, which can destroy the integrity or flatness of the drilling surface, making it easier to break the rock surface and thus proceed with drilling; when the cutting areas of the annular blades 4 overlap, they can complement and reinforce each other. By repeatedly cutting a certain area, the cutting effect is improved, which facilitates improving the rock breaking effect of the drill bit.

[0077] Example 2 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. In this embodiment, the ring-shaped cutter wings 4 are spaced apart and form a spaced area 43.

[0078] like Figure 7 , Figure 10 , Figure 11 , Figure 12 , Figure 13 As shown in this embodiment, the adjacent cutting areas form an interval region 43, and the drill bit with this annular blade 4 layout is defined as an interval-type annular drill bit. For the interval-type annular drill bit, due to the existence of the interval region 43, the drill bit naturally forms a continuous or discontinuous rock ridge 9 at the bottom of the well. The rock stress field at the bottom of the well is reconstructed. The rock that was originally tightly constrained or supported by the surrounding rock becomes a protruding rock ridge 9. The constraint of the surrounding rock is reduced or even lost, so its local strength is significantly reduced. Under the action of the cutting teeth, it is prone to tensile stress failure, which leads to volumetric fracturing, thereby significantly reducing the energy consumption of the drill bit in rock breaking.

[0079] Figure 11 This is a schematic diagram of a micro-coring drill bit, employing an intermittent ring-shaped cutter wing structure. The cutting teeth in the central area are either missing or raised, allowing the drill bit to cut a core column 91 at the center of the wellbore during drilling. The core column 91 can then naturally break off as the drill bit progresses, or the central teeth can be used to break or fracture it. Benefits: Enhanced volumetric fracturing of the rock at the wellbore, reduced rock-breaking energy consumption, and the generation of large-sized cuttings.

[0080] Example 3 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that the ring-shaped cutter wings 4 in this embodiment are spaced apart and form overlapping areas.

[0081] like Figure 8 , Figure 14As shown in this embodiment, the overlapping of adjacent cutting areas is described. The structure with this annular blade 4 layout is defined as a staggered overlapping annular group, meaning that two annular blades 4 with different radial positions have partially overlapping cutting areas covered by their respective blades. Drill bits using this layout are staggered overlapping annular group drill bits, which have strong resistance to circumferential cutting. By placing the overlapping annular group structure in areas of the drill bit prone to circumferential cutting, and because the annular blades 4 themselves have a high local tooth density, and the cutting areas between the blades overlap, it is difficult for annular grooves to form between the teeth in the area where the annular group is located. Furthermore, circumferential cutting, which is easily caused by the failure of individual teeth in conventional drill bits, is also difficult to occur in annular group drill bits.

[0082] exist Figure 14 In the middle, the outermost ring blade 4 (the ring blade 4 adjacent to the outermost ring blade) of each ring blade 4 sector is staggered and overlapped with the outermost ring blade 4 and the third ring blade 4 of the adjacent sector.

[0083] Example 4 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that the ring-shaped cutter wings 4 in this embodiment are spaced apart and form overlapping areas.

[0084] like Figure 9 As shown in this embodiment, to improve the actual rock-breaking ability of the drill bit, another layout of the annular blades 4 can be adopted to form another overlapping situation of the cutting areas. The structure with this layout of annular blades 4 is defined as a co-position overlapping ring group, that is, the covered area 44 has two or more annular blades 4 with an inclusive or contained relationship. The drill bit with this layout structure is a co-position composite ring group drill bit. It can achieve efficient cutting in the local area of ​​the drill bit where the ring group is located by using various composite tooth arrangement methods of different annular blades 4 to meet the needs of different rock-breaking conditions. Rock-breaking energy consumption can be reduced and local invasion ability can be improved by pre-cutting or local cutting contour configuration. The continuous working capacity of the cutting structure can be improved by high and low composite and optimal tooth material matching. The working life of the teeth can also be extended while improving cutting efficiency by optimizing the combination of tooth shapes.

[0085] Example 5 This embodiment discloses a PDC drill bit with a ring-shaped cutter wing. The difference from the above embodiment is that the ring-shaped cutter wing 4 in this embodiment is provided with a second cutting tooth 422.

[0086] When the cutting areas of multiple annular blades 4 are distributed differently, some additional adjustment schemes can be adopted to enhance the drilling and cutting effect. This embodiment optimizes and adopts one of the feasible options: such as Figure 11 , Figure 12 and Figure 13As shown, when an interval region 43 is formed between the cutting areas covered by the two annular blades 4, a plurality of second cutting teeth 422 are provided in the interval region 43. The height of the second cutting teeth 422 is lower than the height of the first cutting teeth 421. The height difference between the second cutting teeth 422 and the first cutting teeth 421 in the axial direction of the drill body 1 is greater than or equal to 0.5hc, where hc is the average height of the first cutting teeth 421 on two adjacent blades. When the cutting areas covered by the two annular blades 4 form an overlapping area, the cutting areas of the two annular blades 4 completely overlap or partially overlap, or the longitudinal cutting positions of the two annular blades 4 form a height difference. When the above scheme is adopted, the second cutting tooth 422 can cut and break the rock ridge 9 in the interval area 43, ensuring the overall mining and drilling efficiency; in the overlapping area formed by the cutting teeth, complete or partial overlap can strengthen the cutting, and the height difference formed at the longitudinal cutting position can continuously cut a certain rock layer position multiple times, and the cutting depth can gradually increase, thereby improving the cutting effect and reducing the probability of cutting tooth damage.

[0087] Figure 12 In the process, the use of spaced ring-shaped cutter wings can significantly reduce the rock-breaking energy consumption of PDC drill bits, and the use of flat crown type (fish tail crown type) makes the drill bit highly aggressive.

[0088] In conjunction with the distribution of different cutting zones mentioned above, the actual distribution is influenced by the structure of the blade wings and the tooth profile distribution of the cutting teeth. The specific factors are not unique. This embodiment optimizes the distribution and adopts some feasible options: the blade wings of the two annular blade wings 4 have different orientations, causing the cutting zones to be spaced out or overlapped; and / or, such as... Figure 23 , Figure 25 , Figure 30 As shown, the two annular blade wings 4 have differentially arranged cutting teeth on their blade bodies, resulting in gaps or overlaps in the cutting areas. When using this scheme, the different orientations of the blade bodies refer to the difference in the radial extension distribution of the two blade bodies, leading to separation or intersection of the cutting areas; while the differential arrangement of cutting teeth on the blade bodies refers to the different diameters or positions of the cutting teeth, resulting in different cutting profiles. Ultimately, the cutting areas of the two annular blade wings 4 are spaced out or overlapped.

[0089] exist Figure 30 In this context, the different tooth profiles can be classified from the following aspects: (1) Side view: straight, oblique, symmetrical, asymmetrical.

[0090] (2) Cutting contour lines: flat, oblique, arc, convex, concave.

[0091] (3) Tooth surface 13: plane, convex arc surface, wedge surface.

[0092] Example 6 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that the distribution area of ​​the ring-shaped cutter wings 4 in this embodiment is further restricted.

[0093] Considering that the linear velocity and wear degree of the drill bit vary at different radii during rotation, the tooth density in the radial region of the drill bit needs to be adjusted. This embodiment optimizes this by adopting one feasible option: the annular cutter wings 4 are distributed in the area outside the concentric circle of one-quarter radius on the end face of the drill bit body 1, or the annular cutter wings 4 are distributed in the area inside the concentric circle of three-quarter radius on the end face of the drill bit body 1. Using the above scheme can maintain the drilling efficiency of the drill bit and reduce the wear of the PDC teeth.

[0094] Example 7 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiments is that the layout structure of the ring-shaped cutter wings in this embodiment is optimized, and one specific layout structure is specified.

[0095] When annular cutter wings are distributed on the drill bit body, in some designs they can be intermittently or continuously arranged on the same circumference, or intermittently or continuously arranged on different circumferences. When the annular cutter wings are intermittently arranged, their position can be controlled, thereby controlling the synchronicity of cutting the rock strata during drilling and improving the cutting effect. This effect can be achieved in various ways and is not limited to one specific method. This embodiment optimizes and adopts one feasible option: such as Figure 11 , Figure 14 As shown, the annular blades are distributed on the end face of the drill bit body, forming several fan-shaped cutting areas. Flow channels are formed between adjacent fan-shaped cutting areas, and water holes are installed within these channels. When using this scheme, during the rotation of the fan-shaped cutting areas, the cutting starting points of multiple annular blades can be located on the same radius, thereby achieving synchronous cutting, resulting in better rock fragmentation and improved drilling and mining efficiency.

[0096] Example 8 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that this embodiment uses a different connection method between the ring-shaped cutter wings 4 and the drill bit.

[0097] The design of the cutter wing body can be further optimized. Besides being directly mounted on the drill bit, the cutter wing body can also be connected and fixed via an intermediate transition structure. This embodiment adopts one feasible option: such as... Figure 11 , Figure 15 , Figure 16 , Figure 20As shown, at least one cutter wing body is disposed on the cutter wing base 45. When cutter wing bases 45 are continuously disposed, a groove is formed between adjacent cutter wing bases 45, forming a drilling fluid flow channel. In the above scheme, the cutter wing base 45 is integrally formed with the drill bit, and the cutter wing base 45 forms a bearing surface for supporting the cutter wing body. The cutter wing body can be integrally formed with the cutter wing base 45. Considering the relatively small thickness of the annular cutter wing 4, in order to ensure the strength and rigidity of the annular cutter wing 4, and at the same time increase the water channel depth to give the drill bit better chip removal effect and improve hydraulic performance such as anti-mud packing, one or more cutter wing bases 45 can be disposed on the drill bit body 1. The cutter wing base 45 is a boss extending from the drill bit body 1. The boss can cover the entire radial area of ​​the drill bit, or it can cover part of the radial area. The peripheral contour of the boss can be fan-shaped or nearly fan-shaped. There is a groove between two adjacent bosses, and a drilling fluid water hole can be disposed in the groove. The annular blade 4 is mounted on the base, and the circumferential spacing between the groove of the blade base 45 and the blade forms a drilling fluid flow channel.

[0098] After the cutter wing base 45 is set, in addition to the cutter wing body, the cutter wing base 45 can also be used to set more structures, thereby improving the drilling effect of the drill bit. This embodiment optimizes and adopts one feasible option: the second cutting tooth 422 is located on the cutter wing base 45 or in the groove between the cutter wing bases 45. When the above scheme is adopted, the second cutting tooth 422 is used to break the rock ridge 9 formed by the interval area 43 between two adjacent annular cutter wings 4, and combined with the cutting of the annular cutter wings 4, a larger cutting surface is formed, improving the breaking effect on the rock strata.

[0099] Example 9 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that, in addition to the ring-shaped cutter wings 4, radial cutter wings 5 ​​are also provided in combination in this embodiment.

[0100] In addition to the annular cutter 4, the drill body 1 can also be equipped with other cutter wing structures to improve the working performance of the drill bit. This embodiment optimizes and adopts one of the feasible options: such as... Figures 15-18 As shown, the drill bit body 1 is provided with radial cutter wings 5. When adopting the above scheme, the number of radial cutter wings 5 ​​can be single or multiple.

[0101] Applying both radial blades 5 and the ring structure composed of annular blades 4 to a drill bit allows for more efficient use of the very limited drill bit space, enabling a more rational and personalized design. On one hand, it allows for better utilization of the advantages of both cutting structures (for example, radial blades 5 can be used in the narrow space of the drill bit's core structure where tooth density is not high, while the ring structure can be arranged in the more challenging and relatively spacious external area). On the other hand, while the radial blades 5 occupy a relatively small circumferential space, they can still contribute to a more balanced force distribution on the drill bit and improve its hydraulic performance. Furthermore, the radial blades 5 can also serve as the base for the second cutting teeth 422, providing them with better cutting and cooling conditions.

[0102] In some schemes, such as Figure 26 , Figure 27 As shown, the first cutting tooth 421 is represented by a round tooth, and the second cutting tooth 422 is located on the radial blade 5 and is represented by a wedge-shaped tooth.

[0103] When radial cutter wings 5 ​​are provided, the radial cutter wings 5 ​​extend outward from the center of the drill bit. The area formed by the length of their extension across a complete circle is the cutting area. The width of the cutting area is limited by the length of their radial extension. This embodiment optimizes this by adopting one feasible option: the width of the cutting area of ​​at least one radial cutter wing 5 is greater than or equal to 30% of the drill bit radius. With the above scheme, there are multiple radial cutter wings 5. The cutting areas of each radial cutter wing 5 can complement each other in the radial direction, forming a complete cutting surface, while also covering the cutting surface of the annular cutter wing 4, thus improving the cutting effect of the drill bit.

[0104] like Figure 26 As shown, when serrulating the radial blades, there are several possible solutions: (a) The radial blade and the ring blade have the same cutting profile, covering the entire area.

[0105] (b) The radial blade and the ring blade have the same cutting profile, covering only the intervening area.

[0106] (c) The radial blade has both first and second cutting teeth. The second cutting teeth are recessed. The two blades form a height difference δh. The first and second cutting teeth are on both blades. The recessed method of the second set of cutting teeth can be achieved by slotting on the blade body or by using a blade tooth surface profile with varying heights. The first cutting tooth 421 is placed in the high region of the blade profile, while the second cutting tooth is placed in the low region of the blade profile.

[0107] (d) The radial blade has both a first and a second cutting tooth. The second cutting tooth is arranged in a recessed manner. The two blades form a height difference δh. The annular tooth arrangement area of ​​one of the blades is only provided with the second cutting tooth.

[0108] (e) The radial blade has a first and a second cutting tooth, with the second cutting tooth arranged in a recessed manner to form two height differences δh1 and δh2, forming a three-blade blade.

[0109] In the bottom cover diagram of the annular cutter wing, the radial cutting area defined by the innermost and outermost cutting teeth is the radial coverage area of ​​the annular cutter wing, which can be used to characterize the width of the radial cutter wing's cutting area.

[0110] In some designs, the relative positions of the radial cutter wing 5 and the annular cutter wing 4 are adjusted. This embodiment optimizes and adopts a feasible option: the radial cutter wing 5 and the annular cutter wing 4 are spaced apart on the circumference, or the cutting area of ​​the annular cutter wing 4 is located outside the overall cutting area of ​​the drill bit, and the cutting area of ​​the radial cutter wing 5 is located inside the overall cutting area of ​​the drill bit. When the above design is adopted, the annular cutter wing 4 is located outside the drill bit. Under the same angular velocity, the linear velocity outside the drill bit is greater, the wear at the PDC teeth is greater, and damage is more likely to occur. By setting the annular cutter wing 4, it is more wear-resistant, and the cutting efficiency and cutting effect are better when used in combination with the radial cutter wing 5.

[0111] Example 10 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiment is that the relationship between the width of the ring-shaped cutter wings 4 and the cutting teeth is limited in this embodiment.

[0112] The actual length and width extension structure of the annular blade 4 needs to be limited to facilitate adjustment of its cutting performance. This embodiment optimizes this by adopting a feasible option: at least one annular blade 4 has a width less than or equal to 1.5 or 2 times the average diameter of the cutting teeth on the blade body; or, at least one annular blade 4 has a width less than or equal to 1.5 or 2 times the width of the largest non-circular profile PDC tooth on the blade body. When using the above scheme, the average diameter or maximum profile of the cutting teeth can be set to be greater than the width of the blade body, thereby avoiding friction between the blade body and the rock layer, allowing only the cutting teeth to cut the rock layer, thus protecting the blade body. In some schemes, the width of the blade body is equal to or greater than the diameter of some cutting teeth. In this case, it is necessary to distribute more cutting teeth in the width direction of the blade body so that the cutting area of ​​the cutting teeth covers the width of the blade body, thereby protecting the blade body.

[0113] Specifically, such as Figures 5-9 , Figure 21 , Figure 22 , Figure 25 , Figure 28 , Figure 29As shown, the cutting area on the bottom-hole cutting profile defined by the innermost and outermost cutting teeth is the bottom-hole profile coverage area 44 of the annular cutter wing 4. The corresponding annular bottom-hole area is the cutting ring of the annular wing. The width of the profile coverage area 44 of the annular cutter wing 4 is defined as the width of the annular cutter wing 4 (t in the figure). The projection length of the width t of the annular cutter wing 4 in the horizontal direction is the horizontal width of the annular cutter wing 4 (i.e., the distance between the inner and outer boundaries of the coverage area 44 of the annular cutter wing 4 measured in the direction perpendicular to the drill bit centerline, see th in the figure). The distance from the midpoint of the coverage area 44 of the annular cutter wing 4 to the drill bit centerline is used as the characteristic dimension characterizing the radial position of the annular wing (Ri, i=1,2,... in the figure). The annular cutter wing cutting ring corresponding to the midpoint of the profile coverage area is the centerline of the ring. The length of the annular cutter wing (w in the figure) refers to the length of the annular cutter wing measured on the centerline of the ring.

[0114] Example 11 This embodiment discloses a PDC drill bit with ring-shaped blades. The difference from the above embodiments is that the specific tooth shape of the cutting teeth is defined in this embodiment.

[0115] The cutting teeth on the blade body can adopt various tooth shapes. This embodiment optimizes them and provides some feasible options: such as... Figure 29 As shown, at least one of the first cutting teeth 421 on the annular blade 4 adopts a pointed tooth (or a wedge-shaped tooth), and / or, at least one of the first cutting teeth 421 on the annular blade 4 adopts a full-cutting edge structure.

[0116] Figure 22 and Figure 23 The paper shows various applications of non-circular profile teeth in ring-type cutter blade drill bits, including different ways of using non-circular profile teeth, non-planar teeth, and conventional cutting teeth in combination. Figure 22 The paper demonstrates three ways in which the flat-edged tooth is used as the first cutting tooth 421. It makes full use of the high curvature tip of the flat-edged tooth to increase the profile curvature of the rock ridge root, significantly increase the stress concentration at the rock ridge root, so as to promote the tensile stress failure of the rock ridge and further reduce its failure strength. Figure 23 It also includes a pre-cutting structure composed of sharp teeth, small-sized round teeth, and elliptical teeth. Through the pre-cutting action of high-curvature teeth, the cutting load of the main cutting teeth at the root of the rock ridge is reduced. And by cutting grooves at the root of the rock ridge, the stress concentration at the root of the rock ridge is increased, thereby reducing the failure strength of the rock ridge.

[0117] To improve the bonding strength of the cutting teeth on the annular blade 4, the base of the tooth can be deflected towards the annular blade body to increase the bonding area between the tooth's side and the annular blade 4. However, this will also increase the side angle of the cutting tooth. Normally, the cutting tooth has high rock-breaking efficiency when cutting in a straight-line manner (side angle zero). Increasing the side angle will reduce the cutting efficiency to some extent. The inclined cutting tooth 425, mounted on the annular blade, allows the working surface of the cutting tooth to operate in a straight-line or near-cutting state, while effectively increasing the bonding area between the tooth's side and the annular blade body, thus ensuring the bonding strength of the tooth.

[0118] Example 12 This embodiment discloses a PDC drill bit with ring-shaped cutter wings. The difference from the above embodiments is that the application of the ring-shaped cutter wings 4 is listed in this embodiment.

[0119] The PDC drill bit in this embodiment can be constructed into various types of drill bits. This embodiment adopts some feasible options: the PDC drill bit includes a core drill bit, a dual-diameter drill bit, a tower drill bit, or a dual-center drill bit.

[0120] In the above applications, in addition to setting the ring-shaped cutter wing structure, it can also be equipped with a toothed wheel 71, a disc cutter, a punch and other motion cutting structures.

[0121] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments under the guidance of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be defined in the claims.

Claims

1. A PDC drill bit with ring-shaped cutter wings, characterized in that: The drill bit body (1) is provided with at least two annular blades (4). The circumferential length of the annular blades (4) is greater than or equal to three times the radial width. The annular blades (4) include blade bodies and a plurality of first cutting teeth (421) provided on the blade bodies.

2. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: Two or more first cutting teeth (421) are provided on at least one of the blade wings; the two first cutting teeth (421) are located at different circumferential positions, and / or the two first cutting teeth (421) are located at different radial positions.

3. The PDC drill bit with ring-shaped cutter wings according to claim 2, characterized in that: The ring-shaped blade (4) has at least one ring segment blade or a ring-like blade, and the front and rear ends of the blade body of the ring segment blade and the ring-like blade are provided with first cutting teeth (421); when a ring-like blade is provided, it includes an arc-shaped ring-like blade, a broken-line ring-like blade, or a string-shaped ring-like blade.

4. The PDC drill bit with ring-shaped cutter wings according to any one of claims 1 to 3, characterized in that: Chip grooves (21) are provided on the blade body in front of at least one first cutting tooth (421).

5. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: The annular blades (4) are located at different radial positions on the drill body (1), and at least two annular blades (4) cover cutting areas that form an interval region (43), or at least two annular blades (4) cover cutting areas that form an overlapping region, or at least one annular blade (4) has a cutting area covered by the cutting area of ​​another annular blade (4).

6. The PDC drill bit with ring-shaped cutter wings according to claim 5, characterized in that: When a gap region (43) is formed between the cutting areas covered by the two annular blades (4), a number of second cutting teeth (422) are provided in the gap region (43). The height of the second cutting teeth (422) is lower than the height of the first cutting teeth (421). The height difference between the second cutting teeth (422) and the first cutting teeth (421) in the axial direction of the drill body (1) is greater than or equal to 0.5hc, where hc is the average height of the first cutting teeth (421) on the two adjacent blade bodies. When the cutting areas covered by the two annular blades (4) form an overlapping area, the cutting areas of the two annular blades (4) completely overlap or partially overlap, or the longitudinal cutting positions of the two annular blades (4) form a height difference.

7. The PDC drill bit with ring-shaped cutter wings according to claim 5 or 6, characterized in that: The two annular blades (4) have different blade orientations, which makes the cutting areas spaced apart or overlapping, and / or the two annular blades (4) have different cutting teeth on their blade bodies, which makes the cutting areas spaced apart or overlapping.

8. The PDC drill bit with ring-shaped cutter wings according to claim 5 or 6, characterized in that: The annular blades (4) are distributed in the area outside the concentric circle of one-quarter radius on the end face of the drill body (1), or the annular blades (4) are distributed in the area inside the concentric circle of three-quarter radius on the end face of the drill body (1).

9. The PDC drill bit with ring-shaped cutter wings according to any one of claims 1 to 3, 5, and 6, characterized in that: The annular blade (4) is distributed on the end face of the drill body (1) and forms several fan-shaped cutting areas. A flow channel is formed between adjacent fan-shaped cutting areas, and water holes are set in the flow channel.

10. The PDC drill bit with ring-shaped cutter wings according to claim 9, characterized in that: At least one blade body is set on the blade base (45). When blade bases (45) are set continuously, a groove is formed between adjacent blade bases (45) and a drilling fluid flow channel is formed.

11. The PDC drill bit with ring-shaped cutter wings according to claim 10, characterized in that: The second cutting tooth (422) is located on the blade base (45) or in the groove between the blade bases (45).

12. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: The drill bit body (1) is provided with radial blades (5).

13. The PDC drill bit with ring-shaped cutter wings according to claim 12, characterized in that: The second cutting tooth (422) is located on the radial blade (5).

14. The PDC drill bit with ring-shaped cutter wings according to claim 13, characterized in that: At least one radial blade (5) has a cutting area width greater than or equal to 30% of the drill bit radius.

15. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: The radial blade (5) and the annular blade (4) are spaced apart on the circumference, or the cutting area of ​​the annular blade (4) is located outside the overall cutting area of ​​the drill bit, and the cutting area of ​​the radial blade (5) is located inside the overall cutting area of ​​the drill bit.

16. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: In the annular blade (4), the width of at least one annular blade (4) is less than or equal to 1.5 times or 2 times the average diameter of the cutting teeth on the blade body; or, the width of at least one annular blade (4) is less than or equal to 1.5 times or 2 times the width of the largest non-circular profile PDC tooth on the blade body.

17. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: At least one of the first cutting teeth (421) on the annular blade (4) is a pointed tooth, and / or, at least one of the first cutting teeth (421) on the annular blade (4) is a full-cutting edge structure.

18. The PDC drill bit with ring-shaped cutter wings according to claim 1, characterized in that: The PDC drill bit includes a core drill bit, a dual-diameter drill bit, a tower drill bit, or a dual-core drill bit.

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