Punching shear drill bit with cone-PDC (Polycrystalline Diamond Compact) composite sheet cutting teeth

Abstract

The utility model discloses a punching shear drill with cone-PDC (Polycrystalline Diamond Compact) cutting teeth. The punching shear drill comprises a drill body, two groups of blades are arranged on the drill body, a first groove is formed between the two groups of blades, cone legs are arranged in the first groove, each cone leg is provided with a cone, and hard alloy cutting teeth are arranged on the cones. The PDC bit has the structural characteristics of a compact bit and the structural characteristics of a roller bit by arranging the PDC compact cutting teeth and the roller cone, in the drilling process, the roller cone firstly makes contact with the stratum, the hard and compact rock stratum is impacted and crushed or cracks are generated through rotation of the roller cone, the integrity of the rock stratum is destroyed, and the rock stratum is prevented from being damaged. During rotation, cutting teeth of the PDC composite sheets shear rocks, impact-shear crushing of the rocks is achieved, the drilling efficiency of the drill bit in a hard and compact stratum is improved by more than 50% through impact-shear composite rock crushing, and the technical problem that an existing PDC drill bit and an existing bit leg drill bit are low in drilling efficiency in the hard rock stratum is solved.

Description

Technical Field

[0001] This utility model belongs to the field of oil and coalbed methane drilling and geological drilling tools, and relates to punching and shearing drill bits, specifically a punching and shearing drill bit with roller cone-PDC composite cutting teeth. Background Technology

[0002] PDC drill bits break rocks through the compressive shearing action of their cutting teeth, fully utilizing the low shear strength of rocks to greatly improve rock-breaking efficiency in soft to medium-hard formations, shorten drilling time, and save drilling costs. However, the overall brittleness and weak impact resistance of PDC composite cutting teeth greatly limit the application of PDC drill bits in hard and complex formations.

[0003] Compared to soft to medium-hard formations, PDC drill bits experience severe impact and vibration when drilling through hard and complex formations. The diamond cutting edge of the PDC composite cutting teeth is easily broken, especially in heterogeneous formations where drill bit vibration is intense and this phenomenon occurs more frequently. Therefore, improving the impact resistance of PDC drill bits, expanding their application range in hard and complex formations, and achieving efficient and rapid drilling in hard and complex formations have become important technical challenges that urgently need to be addressed. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a punching and shearing drill bit with roller cone-PDC composite cutting teeth, so as to solve the technical problem of low drilling efficiency of existing PDC drill bits and toothed drill bits in hard rock formations.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A punching and shearing drill bit with roller cone-PDC composite cutting teeth includes a drill bit body, on which two sets of blades are provided, a first groove is formed between the two sets of blades, a toothed plate is provided in the first groove, each toothed plate is provided with a roller cone, and the roller cone is provided with a carbide cutting tooth; a flushing fluid channel is formed between the two blades in each set, and a water eye is opened in each flushing fluid channel;

[0007] The cutter wing is provided with PDC tooth recesses, and PDC composite cutting teeth are arranged on the PDC tooth recesses; the outer wall of the cutter wing is provided with drill bit diameter protection.

[0008] This invention also includes the following technical features:

[0009] The angle between the top surfaces of the symmetrical blades in the two sets of blades is 144°.

[0010] The included angle between the two blades in each group is 35°.

[0011] The diameter of the PDC tooth socket is 13.8 mm, 16 mm, or 19 mm.

[0012] The vertical height of the PDC composite cutting teeth or the distance between the PDC composite cutting teeth and the axial centerline of the drill bit body are not the same.

[0013] The angle between the surface of the PDC composite cutting tooth and the vertical direction is 5-15°, and the angle between the PDC composite cutting tooth and the tangent of the circumference formed by the PDC composite cutting tooth is 5°.

[0014] The topmost carbide cutting tooth on the roller cone is higher than the topmost PDC composite cutting tooth on the blade.

[0015] The bottom surface and both side walls of the first groove are provided with a slope angle α, which is an acute angle.

[0016] The water inlet is equipped with an alloy water inlet.

[0017] The inner wall of the water eye is provided with fine thread, and the water eye and the alloy water eye are connected by fine thread.

[0018] The alloy water eye has multiple second grooves.

[0019] The bottom of the drill bit body is provided with a connector thread.

[0020] The drill bit body is provided with a drill bit body flattening.

[0021] The angle between the toothed edge and the center line of the drill bit body is 8°.

[0022] Compared with the prior art, the beneficial technical effects of this utility model are:

[0023] (I) By setting PDC composite cutting teeth and roller cones, this utility model combines the structural features of composite drill bits and roller cone drill bits. During drilling, the roller cones first contact the formation and crush or crack the hard and dense rock formations by rotating, thus destroying the integrity of the rock formations. When rotating, the PDC composite cutting teeth shear the rock, realizing impact-shear rock crushing. The impact-shear composite rock crushing improves the drilling efficiency of the drill bit in hard and dense formations by more than 50%, solving the technical problem of low drilling efficiency of existing PDC drill bits and roller cone drill bits in hard rock formations.

[0024] (II) In this application, the cutting edge height of the carbide cutting teeth on the roller cone is higher than that of the PDC composite cutting teeth. This effectively alleviates the damage of drill bit vibration to PDC teeth during drilling, prevents PDC teeth from chipping and delamination, and increases the service life of the drill bit by more than double. Attached Figure Description

[0025] Figure 1 This is a three-dimensional structural schematic diagram of the present invention;

[0026] Figure 2 This is a front view structural diagram of the present utility model;

[0027] Figure 3 This is a top view of the structure of this utility model;

[0028] Figure 4 This is a side view of the structure of this utility model;

[0029] Figure 5 This is a schematic diagram of the alloy water eye structure in this utility model;

[0030] The meanings of the labels in the figure are as follows: 1. Drill body, 2. Blade, 3. First groove, 4. Tooth, 5. Carbide cutting tooth, 6. Fluid flow channel, 7. Water eye, 8. PDC composite cutting tooth, 9. Drill diameter protection, 10. Alloy water eye, 12. Second groove, 13. Connector thread, 14.

[0031] The specific content of this utility model will be further explained in detail below with reference to the embodiments. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, all components in this utility model are components known in the art.

[0033] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0034] This utility model provides a punching and shearing drill bit with roller cone-PDC composite cutting teeth, including a drill bit body 1, on which two sets of blades 2 are provided, and a first groove 3 is formed between the two sets of blades 2. A toothed plate 4 is provided in the first groove 3, and each toothed plate 4 is provided with a roller cone 5. The roller cone 5 is provided with carbide cutting teeth 6. A flushing fluid channel 7 is formed between the two blades 2 in each set, and a water eye 8 is opened in each flushing fluid channel 7.

[0035] The cutter wing 2 has PDC tooth recesses, and PDC composite cutting teeth 9 are arranged on the PDC tooth recesses; the outer wall of the cutter wing 2 is provided with drill bit diameter protection 10.

[0036] In the above technical solution, the toothed palm 4 is connected to the toothed wheel 5 through a sealed bearing. The toothed wheel 5 has a degree of rotational freedom. Multiple sets of cemented carbide cutting teeth 6 are arranged on the circumference of the toothed wheel 5. The high impact toughness of the cemented carbide cutting teeth 6 and the rotational freedom of the toothed wheel are used to achieve impact crushing of rocks and release the stress of the rocks at the bottom of the hole. The toothed palm 4 and the first groove 3 are generally welded together by electric welding.

[0037] The flushing fluid channel 7 and the water hole 8 are located in the annular space between the two blades of the drill bit and between the blade and the tooth. The flushing fluid channel 7 provides space for the drilling fluid to carry rock powder and cool the drill bit, and its design should be smooth and rounded. The water hole 8 is used for the flow of drilling fluid.

[0038] The PDC composite cutting tooth 9 is made of wear-resistant hard phase composite material. It is generally welded to the tooth socket on the drill bit by brazing. As the feed pressure of the drill increases, the PDC composite is pressed into the rock to form a pit. When the drill bit rotates, the PDC composite cutting tooth 9 shears and breaks the rock along with the drill bit.

[0039] The 10mm diameter guarantee ensures the outer diameter of the drill bit and prevents the borehole wall from wearing down the outer blades of the drill bit, thus preventing diameter reduction.

[0040] By incorporating PDC composite cutting teeth 9 and roller cones 5, this design combines the structural features of composite cutting bits and roller cone bits. During drilling, roller cones 5 first contact the formation, and their rotation impacts and crushes the hard, dense rock, creating cracks and disrupting the integrity of the rock. During rotation, PDC composite cutting teeth 9 shear the rock, achieving impact-shear rock breaking. This impact-shear composite rock breaking increases the drilling efficiency of the bit in hard, dense formations by more than 50%, solving the technical problem of low drilling efficiency of existing PDC and roller cone bits in hard rock formations.

[0041] The angle between the top surfaces of the symmetrical blades 2 in the two sets of blades 2 is 144°.

[0042] In the above technical solution, the included angle between the top surfaces of the symmetrical cutter wings 2 is a key parameter designed based on the rock hardness and drill bit stability. Generally, a design with a large inner cone angle is selected for hard rock and directional drilling to increase drill bit stability, while a design with a small inner cone angle is selected for soft rock and conventional rotary drill bits to improve drill bit attack. The preferred design in this solution is 144°.

[0043] The included angle between the two blades 2 in each group is 35°.

[0044] In the above technical solution, the PDC composite cutting teeth on the two blades in each group are staggered, which improves the overall tooth density of the drill bit. The preferred 35° blade angle design ensures that there is sufficient flow channel and powder removal space between the blades on the drill bit, while leaving design space for the double roller cone.

[0045] The diameter of the PDC tooth socket is 13.8mm, 16mm or 19mm.

[0046] In the above technical solution, the tooth arrangement of the PDC composite cutting tooth 9 can be designed in various specifications. Generally, the diameter of the PDC tooth socket is designed to be slightly larger than the size of the PDC composite cutting tooth 9 to reserve sufficient space for solder. The Φ19mm tooth socket has a high mechanical drilling speed in soft rock drilling, but its rock-cutting effect is not good in hard rock drilling. The Φ13.8mm tooth socket has high rock-breaking efficiency in hard rock, and the high tooth density ensures the life of the drill bit. The preferred Φ16mm tooth socket design takes into account the performance characteristics of both.

[0047] The vertical height of the PDC composite cutting tooth 9 or the distance between the PDC composite cutting tooth 9 and the axial centerline of the drill bit body 1 are different.

[0048] In the above technical solution, the tooth height and center distance of the PDC composite cutting teeth 9 of the four blades are different. On the same circumference, the PDC composite cutting teeth 9 with different center distances form multiple non-repeating rock-breaking tracks. The cutting volume of each PDC composite cutting tooth is reduced accordingly, which greatly improves the rock-breaking efficiency and reduces the probability of composite blade damage. In the axial direction, the cutting teeth of different heights enter the rock layers at different depths, which is conducive to destroying the integrity of the rock, releasing rock stress in advance, and further improving the rock-breaking efficiency.

[0049] The cutter blades on the drill bit body 1 are arranged in a streamlined manner.

[0050] The angle between the surface of the PDC composite cutting tooth 9 and the vertical direction is 5-15°, and the angle between the PDC composite cutting tooth 9 and the tangent of the circumference formed by the PDC composite cutting tooth 9 is 5°.

[0051] In the above technical solution, a cutting angle of 5 to 15° is designed between the PDC composite cutting tooth 9 and the axial blade surface to reduce the contact area between the composite and the rock when it is pressed into the rock, thereby increasing the pressure for breaking the rock. Furthermore, a maximum side rotation angle of 5° is designed closer to the outer edge of the drill bit to improve the side cutting and rock breaking efficiency of the outer composite and the overall powder removal capacity of the drill bit.

[0052] The topmost carbide cutting tooth 6 on the gear 5 is higher than the topmost PDC composite cutting tooth 9 on the blade 2.

[0053] In the above technical solution, the height of the roller cone 5 is slightly higher than that of the diamond composite sheet. The carbide cutting teeth 6 on the roller cone 5 first contact the rock and break it under the overall axial load of the drill bit. After the rock is broken by impact, the drill bit rotates and the PDC composite sheet cutting teeth 9 further shear and break it. This effectively alleviates the damage of drill bit vibration to the PDC teeth and prevents phenomena such as chipping and delamination of the PDC composite sheet cutting teeth 9. At the same time, under the combined action of impact-shear breaking, it has the highest rock breaking efficiency. Furthermore, the high exposure of the carbide cutting teeth on the roller cone protects the diamond composite sheet and improves the overall lifespan of the drill bit. This increases the service life of the drill bit by more than double during drilling.

[0054] The bottom surface and both side walls of the first groove 3 are provided with slope angles α, which are acute angles.

[0055] In the above technical solution, the slope angle α is preferably 15°. The tooth 4 is installed on the drill bit body 1 and fixed by welding on three sides. The slope angle design is conducive to the accumulation of solder, improves the welding strength, and prevents the occurrence of incomplete welding.

[0056] The water eye 8 is equipped with an alloy water eye 12.

[0057] In the above technical solution, four threaded alloy water eyes and two fixed alloy water eyes are designed. The alloy water eyes can prevent solid impurities in the drilling fluid from eroding the water eyes of the drill bit body, thereby improving the service life of the drill bit.

[0058] Fine threads are provided on the inner wall of water eye 8, and water eye 8 is connected to alloy water eye 12 through fine threads.

[0059] In the above technical solution, the threaded alloy water eye and the drill bit body are detachable, making it convenient to replace the alloy water eye when the service time is too long.

[0060] Multiple second grooves 13 are provided on the alloy water eye 12.

[0061] In the above technical solution, the second groove 13 facilitates the installation and removal of the gold water eye using tools.

[0062] The bottom of the drill bit body 1 is provided with a connector thread 14.

[0063] In the above technical solution, the bottom of the drill bit body 1 is designed with a connector thread for connecting the drill bit and the drill rod.

[0064] The drill bit body 1 is provided with a drill bit body flattening 11.

[0065] In the above technical solution, the drill body milling flattening 11 is used to clamp the drill body 1 during drill bit installation and disassembly.

[0066] The angle between the toothed palm 4 and the center line of the drill body 1 is 8°.

[0067] In the above technical solution, an included angle of 8° can ensure that the maximum outer diameter of the tooth palm (4) is the same as the maximum outer diameter of the drill bit body 1.

Claims

1. A punching and shearing drill bit with roller cone-PDC composite cutting teeth, comprising a drill bit body (1), characterized in that, The drill bit body (1) is provided with two sets of blades (2), and a first groove (3) is formed between the two sets of blades (2). A toothed plate (4) is provided in the first groove (3), and a toothed wheel (5) is provided on each toothed plate (4). A carbide cutting tooth (6) is provided on each toothed wheel (5). A flushing fluid channel (7) is formed between the two blades (2) in each set, and a water hole (8) is opened in each flushing fluid channel (7). The blade (2) is provided with PDC tooth recesses, and PDC composite cutting teeth (9) are arranged on the PDC tooth recesses; the outer wall of the blade (2) is provided with drill bit gauge protection (10). The vertical height of the PDC composite cutting tooth (9) or the distance between the PDC composite cutting tooth (9) and the axial center line of the drill bit body (1) are different; The angle between the surface of the PDC composite cutting tooth (9) and the vertical direction is 5~15°, and the angle between the PDC composite cutting tooth (9) and the tangent of the circumference formed by the PDC composite cutting tooth (9) is 5°. The topmost carbide cutting tooth (6) on the toothed wheel (5) is higher than the topmost PDC composite cutting tooth (9) on the blade (2).

2. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The angle between the top surfaces of the symmetrical blades (2) in the two sets of blades (2) is 144°.

3. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The included angle between the two blades (2) in each group is 35°.

4. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The diameter of the PDC tooth socket is 13.8 mm, 16 mm, or 19 mm.

5. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The bottom surface and both side walls of the first groove (3) are provided with a slope angle α, which is an acute angle.

6. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The water eye (8) is provided with an alloy water eye (12).

7. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 6, characterized in that, The inner wall of the water eye (8) is provided with fine thread, and the water eye (8) and the alloy water eye (12) are connected by fine thread.

8. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 6, characterized in that, The alloy water eye (12) has multiple second grooves (13).

9. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The bottom of the drill bit body (1) is provided with a connector thread (14).

10. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The drill bit body (1) is provided with a drill bit body flattening (11).

11. The punching and shearing drill bit with roller cone-PDC composite cutting teeth as described in claim 1, characterized in that, The angle between the toothed palm (4) and the center line of the drill bit body (1) is 8°.

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