A bionic PDC-impregnated coupled bionic drill main cutting structure

Abstract

A bionic PDC-impregnated coupled bionic drill bit main cutting structure comprises four bionic PDC cutting teeth and four diamond-impregnated drill bit matrices; the bionic PDC cutting teeth are embedded on the bottom lip surface of the diamond-impregnated drill bit matrices at a certain angle; the bottom lip surfaces of two relatively arranged diamond-impregnated drill bit matrices are provided with pit-shaped bionic units, and the bottom lip surfaces of the other two diamond-impregnated drill bit matrices are provided with bionic PDC cutting teeth. The present invention can overcome the problems of low drilling efficiency of diamond-impregnated drill bits, the defects of PDC cutting teeth losing their rapid drilling function due to excessive wear, and mud packing of drill bits.

Description

Technical Field

[0001] The invention relates to the technical field of drilling equipment, and in particular to a bionic PDC-impregnated coupled bionic drill bit main cutting structure. Background Art

[0002] Conventional PDC cutters have a small force point at the beginning of drilling, making it easy to drill into the formation, and the drill bit has a high rock breaking efficiency; as the working part of the cutter wears, the contact area between the cutter and the rock continues to increase, causing the cutter to become increasingly blunt and drilling to become increasingly difficult. When drilling deep or ultra-deep wells, the drill bit needs to be constantly replaced to ensure normal drilling, which seriously affects the drilling efficiency and increases the drilling cost. When breaking rock, the diamond-impregnated drill bit mainly relies on many small hard points (diamonds) on the bottom lip of the drill bit to scratch and damage the rock. The exposed hard points are constantly worn and consumed, and new hard points continue to be exposed to work. Although its service life has been improved, the drilling speed is low. When the drill bit breaks mudstone and soft rock, the detached rock cuttings will swell when they come into contact with water. If they are not discharged from the bottom of the well in time, they will adhere to the drill bit to form a drill bit mud bag, which will reduce the drilling speed of the drill bit or cause drilling to stop or get stuck. Summary of the invention

[0003] In order to overcome the deficiencies of the above-mentioned prior art, the object of the present invention is to provide a bionic PDC-impregnated coupled bionic drill bit main cutting structure, which can overcome the problems of low drilling efficiency of impregnated diamond drill bits, the defects of PDC cutting teeth losing their rapid drilling function due to excessive wear, and mud packing of drill bits.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A bionic PDC-impregnated coupled bionic drill bit main cutting structure, comprising four bionic PDC cutting teeth 1 and four impregnated diamond drill bit matrices 2;

[0006] The bionic PDC cutting teeth 1 are embedded on the bottom lip surface of the diamond-impregnated drill bit matrix 2 at a certain angle;

[0007] The bottom lip surfaces of two oppositely arranged diamond-impregnated drill bit matrices 2 are provided with concave-shaped bionic units 14 , and the bottom lip surfaces of the other two diamond-impregnated drill bit matrices 2 are provided with bionic PDC cutting teeth 1 .

[0008] The bionic PDC cutting tooth 1 comprises a polycrystalline diamond layer 3 and a cemented carbide layer 4. There are four continuous sawtooth structures 7 at the interface between the polycrystalline diamond layer 3 and the cemented carbide layer 4 of the bionic PDC cutting tooth 1. The two sides of each sawtooth structure are in a vertical relationship.

[0009] The upper surface of the polycrystalline diamond layer 3 has six hemispherical bionic bodies 8, which are arranged in a ring shape at equal intervals on the upper surface of the polycrystalline diamond layer 3. The hemispherical bionic bodies 8 respectively form an inner ring unit body and an outer ring unit body, and the inner ring unit body is located inside the outer ring unit body and is coaxially arranged.

[0010] The corner area 9 formed by the hemispherical bionic body 8 and the upper surface of the polycrystalline diamond layer 3 is used to store a small amount of drilling fluid.

[0011] The cutting edge surface of the bionic PDC cutting tooth 1 has three bionic arc-shaped step tooth structures 5, and the protruding edges of the three arc-shaped step teeth are all on a straight line with a slope of 60 degrees, and the curvature of each bionic arc-shaped step tooth structure 5 is 34.37 degrees.

[0012] The three bionic arc-shaped stepped tooth structures 5 form a trapezoidal groove 6, and the trapezoidal groove 6 is used to store a small amount of drilling fluid.

[0013] There are four diamond-impregnated drill bit matrices 2 forming a ring structure, and there are water inlets 10 between the diamond-impregnated drill bit matrices 2 .

[0014] There are four bionic PDC cutting teeth 1, which are arranged diagonally in pairs on the bottom lip surface of the diamond-impregnated drill bit matrix 2. The bionic PDC cutting teeth 1 on each side are divided into a composite tooth 11 and a main tooth 12, and the back tilt angles of the four bionic PDC cutting teeth 1 are all 20 degrees.

[0015] The compound teeth 11 are lower than the main teeth 12 in the longitudinal direction.

[0016] The concave-shaped bionic unit bodies 14 are evenly arranged on the diamond-impregnated drill bit matrix 2, and the area of ​​the concave-shaped bionic unit bodies 14 accounts for 12.5% ​​of the area of ​​the bottom lip surface.

[0017] A material having a higher wear rate than the drill bit matrix 2 is implanted in the concave-shaped bionic unit body 14 .

[0018] The diamond-impregnated drill bit matrix 2 has a bionic trapezoidal structure 15 arranged on the bottom lip surface with the concave bionic body 14 and along the edge perpendicular to the cutting direction of the drill bit.

[0019] The bottom lip surface of the diamond-impregnated drill bit matrix 2 is randomly distributed with spherical abrasive particles 16 to simulate the real composition of the drill bit matrix material.

[0020] Beneficial effects of the present invention:

[0021] The invention is installed at the end of a drill string, and the drill string transmits drilling pressure and rotation speed to a drill bit. The main cutting structure of the drill bit efficiently crushes rocks and prevents the generation of mud packing on the drill bit.

[0022] The "arc-shaped step tooth" structure reduces the contact area between the rock chips and the cutting edge, thereby greatly reducing the chance of the rock chips staying on the cutting edge surface.

[0023] The trapezoidal groove can store a small amount of drilling fluid, which has a certain lubricating effect on the cuttings flowing through its surface, reducing the friction and adhesion of the cuttings to the cutting edge.

[0024] The sawtooth structure increases the contact area between the two and improves the bonding strength between the two. In addition, there is a heat sink effect, which is conducive to the cooling of the polycrystalline diamond layer and, to a certain extent, alleviates the residual stress concentration caused by the large difference in thermal expansion coefficient, elastic modulus, etc. between the two materials. When the non-smooth layer on the upper surface of the polycrystalline diamond layer is worn, this sawtooth structure can continue to produce a non-smooth shape, allowing the PDC cutting teeth to maintain efficient drilling and a long service life.

[0025] A material with a higher wear rate than the drill bit body is implanted in the pit-shaped bionic unit. During the drilling process, it is worn before the drill bit body, so that the pit-shaped non-smooth shape always exists. This principle is called the self-regeneration principle and is applied to the structural design of the pit-shaped bionic unit on the bottom lip of the diamond impregnated body to increase the overall service life of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 Schematic diagram of the structure of the bionic PDC cutting tooth 1.

[0027] Figure 2 It is a schematic diagram of the structure of the present invention.

[0028] Figure 3 Schematic diagram of the working principle of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0030] like Figure 1-Figure 3 As shown: a bionic PDC-impregnated coupled bionic drill bit main cutting structure, including 4 bionic PDC cutting teeth 1, 4 impregnated diamond drill bit matrix 2, the bionic PDC cutting teeth 1 are embedded on the bottom lip surface of the impregnated diamond drill bit matrix 2 at a certain angle.

[0031] The bionic PDC cutting tooth 1 has a diameter of 13.44 mm and a total height of 8 mm, wherein the polycrystalline diamond layer 3 is 3 mm high and the cemented carbide layer 4 is 5 mm high.

[0032] The cutting edge surface of the bionic PDC cutting tooth has three bionic "arc-shaped step teeth" structures 5, and the protruding edges of the three arc-shaped step teeth are all on a straight line with a slope of 60 degrees. The height of each arc-shaped step tooth is 0.98 mm, the radius is 1.63 mm, and the arc is 34.37 degrees. The "arc-shaped step teeth" structure 5 reduces the contact area between the rock cuttings and the cutting edge, thereby greatly reducing the probability of the rock cuttings staying on the cutting edge surface. The "arc-shaped step teeth" structure 5 decomposes the original single cutting tooth's depth into many small step teeth, and the rock breaking thickness of each step tooth becomes smaller, and the rock is easier to peel off, thereby improving the rock breaking efficiency. Since the "arc-shaped step teeth" structure 5 has the characteristics of "step thickness and layered peeling", it can reduce the force on the PDC cutting teeth in the horizontal and vertical directions. The "arc-shaped step teeth" structure 5 not only reduces the stress concentration of the PDC cutting teeth in the longitudinal direction, but also increases the shear strength of the PDC cutting teeth in the horizontal direction, thereby extending the service life of the PDC cutting teeth.

[0033] The trapezoidal groove 6 can store a small amount of drilling fluid, which plays a certain lubricating role on the rock cuttings flowing through its surface, thereby reducing the friction and adhesion of the rock cuttings to the cutting edge.

[0034] There are four continuous sawtooth structures 7 at the interface between the polycrystalline diamond layer 3 and the cemented carbide layer 4 of the bionic PDC cutting tooth. The two sides of each sawtooth structure are in a vertical relationship, and the length of the two sides is 2.12 mm. This sawtooth structure 7 increases the contact area between the two and improves the bonding strength between the two. In addition, there is a heat sink effect, which is beneficial to the cooling of the polycrystalline diamond layer 3 and alleviates the residual stress concentration caused by the large difference in the thermal expansion coefficient, elastic modulus, etc. of the two materials to a certain extent. When the non-smooth layer on the upper surface of the polycrystalline diamond layer 3 is worn, this sawtooth structure 7 can continue to produce a non-smooth shape, so that the PDC cutting tooth 1 maintains efficient drilling and a long service life.

[0035] The upper surface of the polycrystalline diamond layer 3 of the bionic PDC cutting tooth has 6 hemispherical bionic bodies 8, which are arranged in a ring shape at equal intervals on the upper surface of the polycrystalline diamond layer 3, the inner ring unit bodies are arranged on a circle with a diameter of 4 mm, and the outer ring unit bodies are arranged on a circle with a diameter of 9 mm. The diameter of the hemispherical bionic body 8 is 2 mm.

[0036] The hemispherical structure bionic body 8 reduces the contact area between the rock cuttings and the upper surface of the polycrystalline diamond layer 3, thereby reducing the wear of the rock cuttings on the upper surface of the polycrystalline diamond layer 3. The corner area 9 formed by the hemispherical structure bionic body 8 and the upper surface of the polycrystalline diamond layer 3 can store a small amount of drilling fluid, which has a certain lubricating effect on the rock cuttings flowing through the upper surface of the polycrystalline diamond layer 3, and reduces the friction and adhesion of the rock cuttings to the PDC cutting teeth 1. The hemispherical structure bionic body 8 has the effect of prying, breaking and crushing the rock cuttings. When the rock cuttings flow through the upper surface of the polycrystalline diamond layer 3, the hemispherical structure bionic body 8 pries the rock cuttings, and the rock cuttings are crushed or broken under the action of the prying force, making it difficult for the rock cuttings to adhere and form, effectively preventing the formation of mud packs on the drill bit.

[0037] The diamond-impregnated drill bit matrix 2 is 4 in number, forming an annular structure, with an outer diameter designed to be 96.4 mm, an inner diameter of 55.5 mm, and 4 water inlets 10, each of which is 10 mm wide.

[0038] There are four bionic PDC cutting teeth 1, which are arranged diagonally in pairs on the bottom lip surface of the diamond-impregnated drill bit matrix 2. The bionic PDC cutting teeth 1 on each side are divided into a compound tooth 11 and a main tooth 12, and the back angles of the compound teeth 11 and 12 are 20 degrees to ensure rapid rock breaking. The compound tooth 11 is 2.94mm lower than the main tooth 12 in the longitudinal direction, giving full play to the backup effect of the compound tooth. The distance between the center of the bionic PDC cutting tooth 1 and the edges 13 of the bottom lip surface of the drill bit is greater than 2.5mm, which prevents the bionic PDC cutting tooth 1 from falling off during drilling.

[0039] The bottom lip surface of the diamond-impregnated drill bit matrix 2 is evenly arranged with pit-shaped bionic units 14 with a diameter of 2 mm. The area of ​​these pit-shaped bionic units 14 accounts for 12.5% ​​of the area of ​​the bottom lip surface, thus ensuring that the diamond-impregnated drill bit matrix 2 has the fastest rock breaking speed. In addition, the distance between the center of the pit-shaped bionic unit 14 and the edges 13 of the drill bit bottom lip surface is greater than 2.5 mm, which prevents the pit-shaped bionic unit 14 from falling off. A material with a higher wear rate than the drill bit matrix 2 is implanted in the pit-shaped bionic unit 14, which is worn before the drill bit matrix 2 during the drilling process, so that this pit-shaped non-smooth form always exists. This principle is called the self-regeneration principle and is applied to the structural design of the pit-shaped bionic unit 14 on the bottom lip surface of the diamond impregnated drill bit to increase the overall service life of the drill bit.

[0040] The bottom lip surfaces of two diamond-impregnated drill bit matrices 2 are provided with pit-shaped bionic units 8 , and the bottom lip surfaces of the other two diamond-impregnated drill bit matrices 2 are provided with bionic PDC cutting teeth 1 .

[0041] The diamond-impregnated drill bit matrix 2 has a bionic trapezoidal structure 15 arranged on the bottom lip surface with the pit-shaped bionic body 14 and along the edge perpendicular to the cutting direction of the drill bit to compensate for the disadvantage of low drilling efficiency of the diamond-impregnated drill bit.

[0042] The bottom lip surface of the diamond-impregnated drill bit matrix 2 is randomly distributed with spherical abrasive particles 16 with a radius of 0.1 mm to simulate the real composition of the drill bit matrix material.

[0043] Working principle of the present invention:

[0044] The bionic drill bit is installed at the end of the drill string, and the drill string transmits the drilling pressure and rotation speed to the drill bit. In the early stage of the drill bit breaking the rock, the rock is acted upon by the bionic PDC main cutting teeth 7, the convex and concave bionic units 10 and 8 on the bottom lip of the drill bit, and the edge trapezoidal structure 9; as the drill bit wears, the rock is gradually acted upon by the bionic PDC compound teeth 6, the self-regenerating bionic units 8 on the bottom lip of the drill bit, and the edge trapezoidal structure 9. The bionic PDC cutting teeth and the edge trapezoidal structure jointly make up for the low drilling efficiency of the impregnated diamond drill bit; the compound teeth of the bionic PDC cutting teeth, the self-regenerating bionic units on the bottom lip of the drill bit, and the edge trapezoidal structure jointly make up for the defect that the PDC cutting teeth lose their rapid drilling function due to excessive wear, such as Figure 2 The bionic PDC cutting teeth and the convex and concave bionic unit structures of the bottom lip of the drill bit can solve the problem of mud packing on the drill bit.

Claims

1. A bionic PDC-impregnated coupled bionic drill bit main cutting structure, characterized in that: It includes four bionic PDC cutting teeth (1) and four diamond-impregnated drill bit matrices (2); The bionic PDC cutting teeth (1) are embedded at a certain angle on the bottom lip surface of the diamond-impregnated drill bit matrix (2); The bottom lip surfaces of two diamond-impregnated drill bit matrices (2) arranged opposite to each other are provided with concave-shaped bionic units (14), and the bottom lip surfaces of the other two diamond-impregnated drill bit matrices (2) are provided with bionic PDC cutting teeth (1); There are four bionic PDC cutting teeth (1), which are arranged diagonally in pairs on the bottom lip surface of the diamond-impregnated drill bit matrix (2), and the bionic PDC cutting teeth (1) on each side are divided into a composite tooth (11) and a main tooth (12), and the back tilt angles of the four bionic PDC cutting teeth (1) are all 20 degrees; The compound teeth (11) are lower than the main teeth (12) in the longitudinal direction; The concave-shaped bionic unit bodies (14) are evenly arranged on the diamond-impregnated drill bit matrix (2), and the area of ​​the concave-shaped bionic unit bodies (14) accounts for 12.5% ​​of the area of ​​the bottom lip surface; A material having a higher wear rate than the drill bit matrix (2) is implanted in the concave-shaped bionic unit body (14); The diamond-impregnated drill bit matrix (2) has a bionic trapezoidal structure (15) arranged on the bottom lip surface of the bionic unit body (14) with a concave pit and along the edge perpendicular to the cutting direction of the drill bit; The cutting edge surface of the bionic PDC cutting tooth (1) has three bionic arc-shaped step tooth structures (5), the protruding edges of the three arc-shaped step teeth are all located on a straight line with a slope of 60 degrees, and the curvature of each bionic arc-shaped step tooth structure (5) is 34.37 degrees; The compound tooth (11) is 2.94 mm lower than the main tooth (12) in the longitudinal direction; The distance between the center of the bionic PDC cutting tooth (1) and each edge (13) of the bottom lip surface of the drill bit is greater than 2.5 mm.

2. A bionic PDC-impregnated coupled bionic drill bit main cutting structure according to claim 1, characterized in that: The bionic PDC cutting tooth (1) comprises a polycrystalline diamond layer (3) and a cemented carbide layer (4), and four continuous sawtooth structures (7) are provided at the interface between the polycrystalline diamond layer (3) and the cemented carbide layer (4), and two sides of each sawtooth structure (7) are in a perpendicular relationship.

3. A bionic PDC-impregnated coupled bionic drill bit main cutting structure according to claim 2, characterized in that: The upper surface of the polycrystalline diamond layer (3) has six hemispherical structure bionic bodies (8), which are arranged in a ring shape at equal intervals on the upper surface of the polycrystalline diamond layer (3), and the hemispherical structure bionic bodies (8) respectively form an inner ring unit body and an outer ring unit body, and the inner ring unit body is located inside the outer ring unit body and is coaxially arranged.

4. A bionic PDC-impregnated coupled bionic drill bit main cutting structure according to claim 3, characterized in that: The corner area (9) formed by the hemispherical bionic body (8) and the upper surface of the polycrystalline diamond layer (3) is used to store a small amount of drilling fluid.

5. The bionic PDC-impregnated coupled bionic drill main cutting structure according to claim 1, characterized in that: The three bionic arc-shaped stepped tooth structures (5) form a trapezoidal groove (6), and the trapezoidal groove (6) is used to store a small amount of drilling fluid.

6. The bionic PDC-impregnated coupled bionic drill bit main cutting structure according to claim 1, characterized in that: There are four diamond-impregnated drill bit matrices (2) forming a ring structure, and water inlets (10) are located between the diamond-impregnated drill bit matrices (2).

7. The bionic PDC-impregnated coupled bionic drill main cutting structure according to claim 1, characterized in that: The bottom lip surface of the diamond-impregnated drill bit matrix (2) is randomly distributed with spherical abrasive particles (16) for simulating the real composition of the drill bit matrix material.

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