CN117188979B - A drill tooth with a parent-child tooth structure, a manufacturing method and a drill bit - Google Patents

Abstract

The invention discloses a drilling tooth with a primary-secondary tooth structure, a manufacturing method and a drill bit, and relates to the technical field of geological drilling, wherein the drilling tooth comprises a primary tooth made of hard alloy and a cylindrical secondary tooth made of CVD diamond, the primary tooth is provided with a cutting area for cutting rock strata, and a welding groove is formed in the cutting area; in the radial direction of the drilling tooth, the section of the welding groove is in a major arc shape or a circular shape; the sub-teeth are welded in the welding groove; according to the invention, the main tooth made of the hard alloy is provided with the welding groove with the arc shape or the circular shape, and the welding groove is internally provided with the welding teeth, so that more than half of the teeth are wrapped by the main tooth, and the connection strength of the CVD diamond and the hard alloy can be improved. Meanwhile, the sub-teeth of the CVD diamond are arranged in the cutting area of the drilling tooth, so that the wear resistance of the cutting area of the drilling tooth can be obviously improved, and the performance and the service life of the drilling tooth are greatly improved.

Description

A drill tooth with a parent-child tooth structure, a manufacturing method and a drill bit

Technical field

The present invention relates to the technical field of geological drilling, and in particular to a drill tooth with a parent-child tooth structure, a manufacturing method and a drill bit.

Background technique

The drill teeth of the well-known geological drill bits mainly include polycrystalline diamond composite (PDC diamond) drill teeth, powder metallurgy impregnated diamond drill teeth, and cemented carbide drill teeth. Drill bits for deep well drilling mainly use PDC diamond composite sheets to make drill teeth. The performance of the drill teeth directly determines the drilling efficiency and service life. During the deep well drilling and coring processes, underground high temperatures (over 300°C), high-speed impact, and grinding The complex environment formed by the coupling of multiple factors such as grain wear and corrosion will lead to PDC thermal corrosion and mechanical damage and serious wear. Especially when the drilling depth exceeds 6,000 meters, the drilling efficiency will be reduced by more than 50%.

At present, there are two main aspects of research work on how to improve the performance of geological drill bits. One is to improve the composition of PDC drill bits; the other is to optimize the overall structural design of the drill bit.

When improving the composition of PDC drill teeth, fine-grained (0-2μm) polycrystalline diamond doped with 0.5% nano-vanadium carbide was sintered. It was found that the hardness and impact resistance of the sample doped with vanadium carbide were 66.65GPa and 160J respectively. , an increase of 8.7% and 100% compared to the undoped sample. At the same time, because the harder vanadium carbide occupies the space of cobalt in polycrystalline diamond, its wear resistance is effectively improved.

This method starts from the perspective of improving PDC diamond additives to improve the wear resistance of polycrystalline diamond, but the performance improvement is limited. It is impossible to fundamentally solve the shortcomings of PDC materials such as easy diamond shedding, poor strength and toughness, and the wear of drill teeth is still serious.

The Chinese patent application number 202310786831.5 discloses a new type of beak-shaped tooth multi-blade PDC drill bit. The drill bit base body is arranged with water eyes, blades and teeth, and adopts a design scheme of nine blades evenly distributed at 40° in the circumferential direction. The beak-shaped PDC main teeth and auxiliary teeth are arranged in staggered rows. During the working process, the main teeth penetrate and split, and the auxiliary teeth shear together to break the rock. The design of multiple blades balances the force distribution between the bottom rock and the blades, effectively reducing the amount of tooth wear per unit time.

This technology starts from the overall structure of the drill bit and improves the arrangement of the drill teeth. The drill teeth themselves still use the traditional PDC drill teeth, which solves to a certain extent technical problems such as severe wear of the cutting parts of the drill bit and slow tooth feed. However, The performance of the drill teeth themselves is not improved.

The Chinese patent application number 201710447313.5 discloses a diamond composite drill bit for hard and slippery formations. The drill bit is composed of a rigid body and an impregnated insert cutting blade. The lip surface of the blade has a slope and is machined with a corrugated groove. The cutting end of the wing is inlaid with a layer of PCD diamond cutting strips or CVD diamond cutting strips. By rationally arranging the diamond cutting strips and impregnated diamonds, and taking advantage of the difference in hardness between the matrix and the diamond, the drill bit life and drilling efficiency are improved.

In this technology, diamonds are embedded on the side of the drill bit and are not used as the main cutting edge for drilling. They are mainly used to maintain the diameter of the drilled hole. Diamond cutting strips do not require a sharp cutting edge.

The above work has improved the performance of geological drill bits to a certain extent, but it cannot significantly improve the drilling capabilities of the drill bit to meet the requirements of deep well drilling.

Contents of the invention

The purpose of the present invention is to provide a drill tooth with a parent-child tooth structure, a manufacturing method and a drill bit, so as to solve the problems existing in the existing technology, overcome the technical problem that CVD diamond is difficult to apply to the drill tooth, and can significantly improve the drilling tooth. The wear resistance of the cutting area greatly improves the performance and service life of the drill teeth.

In order to achieve the above object, the present invention provides the following solution: The present invention provides a drill tooth with a parent tooth structure, including a parent tooth made of cemented carbide and a cylindrical daughter tooth made of CVD diamond, so The mother tooth has a cutting area for cutting rock formations, a welding groove is provided in the cutting area, and the daughter teeth are welded in the welding groove; in the radial direction of the drilling tooth, the welding groove The cross-section is an arcuate shape or a circular shape. When the cross-section of the welding groove is an arcuate shape, the outer arc surface of the daughter tooth coincides with the arc surface of the mother tooth. When the cross-section of the welding groove is It has a circular shape, and the arc surface of the daughter tooth is inscribed in the arc surface of the mother tooth.

Preferably, there are one or more sub-teeth. When there are more than one sub-teeth, the diameters of several sub-teeth are the same or different. When the diameters of several sub-teeth are the same, the diameters of several sub-teeth are the same. The sub-teeth are evenly distributed in the cutting area. When the diameters of the sub-teeth are different, the sub-teeth are distributed in the cutting area, and the sub-teeth with a larger diameter are arranged in the cutting area. Locations with high internal wear.

Preferably, the end surface of the daughter tooth is flush with the end surface of the mother tooth.

Preferably, the distance between adjacent sub-teeth is D, which satisfies 2×(R1+R2)≥D≥R1+R2, and R1 and R2 are the radii of adjacent sub-teeth respectively.

Preferably, the cutting edge of the sub-teeth is chamfered, and the chamfering angle is 10°~30°.

The invention also discloses a method for manufacturing drill teeth with a parent-child tooth structure, which is characterized in that it includes the following steps:

S1: Process welding grooves on the mother teeth;

S2: Process CVD diamond into cylindrical sub-teeth;

S3: Put the sub-teeth into the welding tank, add solder powder, and weld under vacuum conditions.

Preferably, in S1, the electric spark etching process is used to process the welding groove; in S2, the laser cutting process is used to process the sub-teeth.

The invention also discloses a drill bit, which includes a number of blades evenly arranged along the circumferential direction. The blades are provided with a number of drill teeth as described above. The projections of the drill teeth in the circumferential direction are complementary. The drill bit The projections of the sub-teeth in a plurality of the drill teeth in the circumferential direction are complementary.

Compared with the prior art, the present invention achieves the following technical effects:

In the present invention, an arcuate or circular welding groove is provided on a mother tooth made of cemented carbide, and sub-teeth made of CVD diamond are impregnated and welded in the welding groove, and most of the sub-teeth are wrapped by the mother tooth. It can improve the connection strength between CVD diamond and cemented carbide, and overcome the technical problem of difficult application of CVD diamond on drill teeth. At the same time, setting CVD diamond sub-teeth in the cutting area of the drill teeth can significantly improve the wear resistance of the cutting area of the drill teeth, greatly improving the performance and service life of the drill teeth. Drilling deep hard rock formations will produce A major breakthrough, bringing huge economic and social benefits.

Description of the drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the drawings of the present invention. Embodiments, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without exerting creative efforts.

Figure 1 is a schematic diagram of the drill tooth structure of fully impregnated welded equal-diameter sub-teeth;

Figure 2 is a schematic diagram of the drill tooth structure of semi-pregnant welded equal diameter sub-tooth;

Figure 3 is a schematic diagram of the drill tooth structure of fully impregnated welded teeth with unequal diameters;

Figure 4 is a schematic diagram of the drill tooth structure of semi-pregnant welded teeth with unequal diameters;

Figure 5 is a schematic diagram of the structure of a sub-tooth drill tooth by semi-pregnant welding;

Among them, 1. Mother tooth; 2. Daughter tooth.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of the present invention.

The purpose of the present invention is to provide a drill tooth with a parent-child tooth structure, a manufacturing method and a drill bit, so as to solve the problems existing in the existing technology, overcome the technical problem that CVD diamond is difficult to apply to the drill tooth, and can significantly improve the drilling tooth. The wear resistance of the cutting area greatly improves the performance and service life of the drill teeth.

In order to make the above objects, features and advantages of the present invention more obvious and understandable, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

Example 1:

As shown in Figures 1 to 5, this embodiment provides a drill tooth with a parent tooth structure, including a parent tooth 1 made of cemented carbide and a cylindrical child tooth 2 made of CVD diamond. The tooth 1 has a cutting area for cutting rock formations, and one or more welding grooves are provided in the cutting area. In this embodiment, the mother tooth 1 is cylindrical before the welding groove is opened, and the axial direction of the welding groove is parallel to the axial direction of the mother tooth 1 . In the radial direction of the drill tooth, the cross section of the welding groove is an arcuate shape. The central angle corresponding to the arc in the arcuate shape is greater than 180°. The opening of the welding groove is exposed from the surface of the mother tooth 1, and the arc shape corresponds to the center angle of the circle. The angle is greater than 180°, the cross-sectional shape of the sub-tooth 2 matches the cross-sectional shape of the welding groove, and the outer arc surface of the sub-tooth 2 coincides with the arc surface of the mother tooth 1. Or the cross-section of the welding groove is circular, and the sub-tooth 2 is also cylindrical. After the welding is completed, the sub-tooth 2 is inscribed with the surface of the parent tooth 1. The sub-teeth 2 are welded in the welding groove. When there is one welding groove, the structure of the welding groove can only be an arcuate shape. In this embodiment, a superior arcuate or circular welding groove is provided on the mother tooth 1 made of cemented carbide, and the daughter teeth 2 made of CVD diamond are impregnated and welded in the welding groove. More than half of the child teeth 2 are welded by the mother tooth. The wrapping of tooth 1 can improve the connection strength between CVD diamond and cemented carbide, and overcome the technical problem of difficult application of CVD diamond on drilling teeth. At the same time, setting CVD diamond sub-teeth 2 in the cutting area of the drill teeth can significantly improve the wear resistance of the cutting area of the drill teeth and greatly improve the performance and service life of the drill teeth. Drilling deep hard rock formations will produce A major breakthrough, bringing huge economic and social benefits.

In this embodiment, the female tooth 1 is made of YG6 cemented carbide, with a diameter of 10mm~30mm and a height of 5mm~50mm. The cylindrical sub-tooth 2 has a height of 2mm~5mm and a diameter of 4mm~10mm. The smaller height of the sub-teeth 2 will affect the total area of the welding, thereby affecting the welding strength; the larger diameter will cause greater thermal stress after welding, thereby affecting its performance.

The number of sub-teeth 2 in this embodiment may be one, or two or more. When the number of sub-teeth 2 is set to 2 or more, the diameters of sub-teeth 2 are the same or different. When the diameters of several sub-teeth 2 are different, the sub-tooth 2 with larger diameter is set at the place where the wear degree of drill teeth is high. Location. Regardless of whether the diameters of sub-teeth 2 are the same or different, assuming that the distance between adjacent sub-teeth 2 is D, it needs to satisfy 2×(R1+R2)≥D≥R1+R2, R1 and R2 are adjacent sub-teeth 2 respectively. radius.

In this embodiment, the end surface of the daughter tooth 2 is flush with the end surface of the mother tooth 1 .

In this embodiment, the cutting edge of the sub-tooth 2 is chamfered, the chamfering angle is 10°~30°, and the chamfering width is 0.05mm~0.3mm. The chamfered part of the sub-tooth 2 is the main cutting edge of the drill tooth.

Example 2:

This embodiment discloses a method for manufacturing drill teeth with a parent-child tooth structure, which is characterized by including the following steps:

S1: Process the welding groove on the female tooth 1;

S2: Process CVD diamond into cylindrical sub-teeth 2;

S3: Put the sub-teeth 2 into the welding tank, add solder powder, and weld under vacuum conditions.

In S1, the electric spark etching process is used to process the welding groove; in S2, the laser cutting process is used to process the sub-tooth 2.

The manufacturing method of drill teeth in this embodiment is described in detail below through several specific processing examples of drill teeth with different structures.

Example 1:

Produce drill teeth with tooth diameter Φ19mm, fully pregnant welding, 5 sub-teeth and 2 equal diameters.

Step 1: Select a CVD diamond with a thickness of more than 4mm, grind one side flat and polish the other side on a diamond flat grinder. The polished side reaches a mirror level and the thickness of the CVD diamond reaches 4mm.

Step 2: Use a YAG laser to cut out five cylindrical teeth 2 with a diameter of 4.4mm and a height of 4mm from the CVD diamond made in the first step, and clean them.

Step 3: Select a YG6 carbide cylinder as the blank for the mother tooth 1. The diameter of the blank is 23mm and the height is 20mm. Five cylindrical welding grooves with a diameter of 4.4mm and a depth of 4mm were processed by EDM etching on the upper surface of the blank. The distance between the centers of adjacent welding grooves is 4.7mm. The center of each welding groove is between the center of the circle of the carbide cylinder and the center of the carbide cylinder. The distance between them is 7.3mm. Clean them after finishing.

Step 4: Put the sub-tooth 2 and an appropriate amount of silver, copper and titanium solder powder into the welding groove of the mother tooth 1, with the bright side of the sub-tooth 2 facing up. The daughter tooth 2 and the mother tooth 1 are pressed with an alumina ceramic sheet with a thickness of 0.2mm, and a 100g weight is pressed on top of the ceramic sheet. The whole is then placed in a vacuum furnace.

Step 5: Evacuate to 2×10-3Pa, heat to 860°C, keep warm for 1 hour, then slowly cool down for 2 hours to below 200°C, and shut down.

Step 6: Take out the welded primary drill tooth sample block and remove the ceramic pieces on the upper surface. If there are ceramic pieces welded on the upper surface by solder, use an ultra-fine diamond grinding wheel to grind them off on a special diamond tool grinder. And keep the upper surface flat and smooth. Taking the cylindrical central axis of the mother tooth 1 as the rotation axis, use a special diamond grinder to grind the outer circle of the mother tooth 1 to a diameter of Φ19mm.

Step 7: Use a special diamond grinder to chamfer the upper edge of the cylinder of mother tooth 1. The angle between the chamfer and the upper surface is 10°, and the chamfer width is 0.2mm.

Step 8: Inspection, marking, and packaging.

Completed the production of drill teeth with a diameter of Φ19mm, a height of 20mm, five equal-diameter teeth 2, and a fully impregnated welded primary and secondary tooth structure. The drill tooth structure is shown in Figure 1.

Example 2: Make a drill tooth with a tooth diameter of Φ16mm, semi-pregnant welding, 5 sub-teeth and 2 equal diameters.

Step 1: Same as Example 1 Step 1

Step 2: Same as step 1 in Example 1

Step 3: Same as step 1 in Example 1

Step 4: Same as step 4 in Example 1

Step 5: Same as step 1 in Example 1

Step 6: Take out the welded primary drill tooth sample block and remove the ceramic pieces on the upper surface. If there are ceramic pieces welded on the upper surface by solder, use an ultra-fine diamond grinding wheel to grind them off on a special diamond tool grinder. And keep the upper surface flat and smooth.

Taking the cylindrical central axis of the mother tooth 1 as the rotation axis, use a special diamond grinder to grind the outer circle of the mother tooth 1 to a diameter of Φ16mm.

Step 7: Same as step 7 in Example 1.

Step 8: Same as step 8 in Example 1.

A drill tooth with a diameter of Φ16mm, a height of 20mm, five equal-diameter teeth 2, and a semi-pregnant welded primary tooth structure was obtained. The drill tooth structure is shown in Figure 2.

Example 3: Making a drill tooth with a tooth diameter of Φ16mm, a height of 20mm, 4 sub-teeth 2 of non-equal diameter, and a fully impregnated welded sub-tooth structure.

Step 1: Select a CVD diamond with a thickness of more than 3mm, grind one side flat on a diamond flat grinder, and polish the other side. The polished side reaches a mirror level and the thickness of the diamond reaches 3mm.

Step 2: Use a YAG laser to cut out two cylindrical sub-teeth 2 with a diameter of 5mm and a height of 3mm and two sub-teeth 2 with a diameter of 4mm and a height of 3mm from the CVD diamond made in the first step, and clean them.

Step 3: Select a YG6 carbide cylinder as the blank for the mother tooth 1, with a diameter of 18mm and a height of 20mm. Two cylindrical welding grooves with a diameter of 5mm and a depth of 3mm and two welding grooves with a diameter of 4mm and a depth of 3mm were processed by EDM etching on the upper surface of the blank. Adjacent welding grooves do not intersect, and the outer arc of each welding groove is inscribed in the concentric circle of the mother tooth 1 with a diameter of 16mm; clean it after completion.

Step 4: Place the four sub-teeth 2 into the corresponding welding slots and add an appropriate amount of solder, with the bright side of the sub-teeth 2 facing up. The mother tooth 1 and the daughter tooth 2 are pressed with an alumina ceramic sheet with a thickness of 0.2mm. A 100g weight is pressed on top of the ceramic sheet, and then the whole is placed in the vacuum furnace.

Step 5: Same as step 5 in Example 1.

Step 6: Take out the welded primary drill tooth sample block and remove the ceramic pieces on the upper surface. If there are ceramic pieces welded on the upper surface by solder, use an ultra-fine diamond grinding wheel to grind them off on a special diamond tool grinder. And keep the upper surface flat and smooth. Taking the cylindrical central axis of the mother tooth 1 as the rotation axis, use a special diamond tool grinder to grind the outer circle of the mother tooth 1 to a diameter of Φ16mm.

Step 7: Same as step 7 in Example 1.

Step 8: Same as step 8 in Example 1.

A drill tooth with a diameter of Φ16mm, a height of 20mm, four sub-teeth 2 of non-equal diameter, and a fully impregnated welded sub-tooth structure was obtained. The drill tooth structure is shown in Figure 3.

Example 4: Making a drill tooth with a tooth diameter of Φ13mm and a semi-pregnant welding structure of 4 sub-teeth and 2 non-equal diameter sub-tooth structures.

Step 1: Same as step 3 in Example 3.

Step 2: Same as the second step in Example 3.

Step 3: Same as step 3 in Example 3.

Step 4: Same as step 4 in Example 3.

Step 5: Same as step 5 in Example 3.

Step 6: Take out the welded sample block with mother-in-line drill teeth and remove the ceramic pieces on the upper surface. If there are ceramic pieces welded on the upper surface by solder, use an ultra-fine diamond grinding wheel to grind them off on a special diamond tool grinder. , and keep the upper surface flat and smooth. Taking the cylindrical central axis of the mother tooth 1 as the rotation axis, use a special diamond tool grinder to grind the outer circle of the mother tooth 1 to a diameter of Φ13mm.

Step 7: Same as step 7 in Example 3

Step 8: Same as step 8 in Example 3

A drill tooth with a semi-pregnant welded parent tooth structure with a diameter of Φ13mm, a height of 20mm, and four non-equal diameter teeth 2 is obtained. The drill tooth structure is shown in Figure 4.

Example 5: Make a drill tooth with sub-tooth 2 and semi-pregnant welding structure.

According to the above steps, a drill tooth with a parent tooth structure of a parent tooth 1 with a diameter of 13mm and a height of 20mm, and a daughter tooth 2 with a diameter of 10.0mm and semi-pregnant welding can be produced. The drill tooth structure is shown in Figure 5.

Example 3:

This embodiment discloses a drill bit, which includes a plurality of blades evenly arranged along the circumferential direction. The blades are provided with a plurality of drill teeth as described above. The projections of the plurality of drill teeth in the circumferential direction are complementary. The plurality of drill teeth on the drill have neutron teeth. 2's projections in the circumferential direction are complementary, ensuring that when the drill bit rotates once, the sub-teeth 2 can remove rocks within the circumferential range, and can also protect the mother teeth 1, improve drilling efficiency, and extend the service life of the drill bit.

Adaptive changes based on actual needs are within the scope of the present invention.

It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. . Therefore, the embodiments should be regarded as illustrative and non-restrictive from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is therefore intended that all claims falling within the claims All changes within the meaning and scope of equivalent elements are included in the present invention. Any reference signs in the claims shall not be construed as limiting the claim in question.

Claims (8)

1. The drill tooth with the primary-secondary tooth structure is characterized by comprising a primary tooth made of hard alloy and a cylindrical secondary tooth made of CVD diamond, wherein the primary tooth is provided with a cutting area for cutting a rock stratum, a welding groove is formed in the cutting area, and the secondary tooth is welded in the welding groove by utilizing a vacuum welding process; in the radial direction of the drilling tooth, the section of the welding groove is in a major arc shape or a circular shape, when the section of the welding groove is in a major arc shape, the outer arc surface of the sub tooth is overlapped with the arc surface of the main tooth, and when the section of the welding groove is in a circular shape, the arc surface of the sub tooth is inscribed with the arc surface of the main tooth.

2. The drill tooth with a primary-secondary tooth structure according to claim 1, wherein the number of the secondary teeth is 1 or more, when the number of the secondary teeth is 1 or more, the diameters of the number of the secondary teeth are the same or different, when the diameters of the number of the secondary teeth are the same, the number of the secondary teeth are distributed in the cutting area, when the diameters of the number of the secondary teeth are different, the number of the secondary teeth are distributed in the cutting area, and the secondary teeth with larger diameters are arranged at positions with high wear degrees in the cutting area.

3. The drill tooth having a primary and secondary tooth structure as claimed in claim 1, wherein an end face of said primary tooth is flush with an end face of said secondary tooth.

4. The drill tooth with the primary-secondary tooth structure according to claim 2, wherein the distance between adjacent primary teeth is D, 2× (r1+r2) > D is equal to or greater than r1+r2, and R1 and R2 are radii of adjacent primary teeth, respectively.

5. The drill tooth with the primary-secondary tooth structure according to claim 1, wherein the cutting edges of the primary teeth are chamfered, and the chamfer angle is 10-30 degrees.

6. The method for manufacturing the drill tooth with the primary-secondary tooth structure according to any one of claims 1 to 5, comprising the following steps:

s1: processing a welding groove on the female tooth;

s2: machining the CVD diamond into cylindrical sub-teeth;

s3: and placing the sub-teeth into a welding groove, placing welding powder, and welding under vacuum condition.

7. The method for manufacturing the drill tooth with the primary-secondary tooth structure according to claim 6, wherein the welding groove is processed by adopting an electric spark etching process in the step S1; and S2, machining the sub-teeth by adopting a laser cutting process.

8. A drill bit, characterized by comprising a plurality of blades uniformly arranged along the circumferential direction, wherein a plurality of drilling teeth according to any one of claims 1-5 are arranged on the blades, projections of the plurality of drilling teeth in the circumferential direction are complementary, and projections of sub-teeth in the plurality of drilling teeth in the circumferential direction on the drill bit are complementary.