Polycrystalline diamond compact and gauge drill bit

Abstract

The invention relates to a polycrystalline diamond compact and a gauge drill bit. The polycrystalline diamond compact comprises a diamond layer and a substrate which are integrated, an embedding groove matched and corresponding to the diamond layer is formed in the center of the top of the base body; the diamond layer is embedded into the embedding groove; the top surface of the diamond layer does not exceed the notch of the embedding groove; the edge of the top of the base body replaces an existing diamond layer to be in brazed connection with the drill bit body, gaps between the polycrystalline diamond compact and the drill bit body are avoided, and the probability that the edge of the top of the polycrystalline diamond compact is cracked is reduced. The drill bit further comprises a drill bit body, a first cutting composite piece and a second cutting composite piece. According to the gauge protection drill bit, the service life can be prolonged.

Description

Technical Field

[0001] This invention relates to the technical field of gauge-maintaining drill bits, and in particular to a polycrystalline diamond composite sheet and a gauge-maintaining drill bit. Background Technology

[0002] Gauge-maintaining drill bits are drill bits designed with special gauge-maintaining structures to keep the wellbore diameter constant during drilling, preventing wellbore shrinkage or deformation. Polycrystalline diamond composite sheets are frequently used in both the cutting and gauge-maintaining sections of gauge-maintaining drill bits, specifically cutting composite sheet 01 and gauge-maintaining composite sheet 02. See also... Figure 1 The existing cutting composite plate 01 and gauge-maintaining composite plate 02 have basically the same structure. However, their installation states differ. The tail end of the cutting composite plate 01 is brazed to the head end of the drill bit body, meaning the carbide substrate of the cutting composite plate 01 is brazed to the head end of the steel drill bit body. The head end of the cutting composite plate 01 does not contact the drill bit body; while the gauge-maintaining composite plate 02 is embedded in the side wall of the drill bit body, not extending beyond it. The carbide substrate of the gauge-maintaining composite plate 02 is also brazed to the drill bit body. However, the polycrystalline diamond layer does not wet the brazing filler. A gap remains between the polycrystalline diamond layer of the gauge-maintaining composite plate 02 and the drill bit body; the polycrystalline diamond layer of the gauge-maintaining composite plate 02 is easily chipped at the edges due to compression, causing premature failure of the gauge-maintaining composite plate 02. Summary of the Invention

[0003] The purpose of this invention is to solve the above-mentioned problems and provide a polycrystalline diamond composite sheet and a gauge-maintaining drill bit.

[0004] The technical solution of this invention is as follows: A polycrystalline diamond composite sheet includes an integral diamond layer and a matrix; the diamond layer and the matrix are formed by high-pressure and high-temperature sintering; the top center of the matrix is ​​provided with an insert groove that matches the diamond layer, for holding the diamond powder used to form the diamond layer; after the diamond powder enters the insert groove, it is sintered under high temperature and high pressure to form a state in which the diamond layer is embedded in the insert groove; the top surface of the diamond layer does not exceed the opening of the insert groove; the top edge of the matrix is ​​brazed to the drill bit body instead of the existing diamond layer, avoiding gaps between the polycrystalline diamond composite sheet and the drill bit body, and reducing the probability of chipping at the top edge of the polycrystalline diamond composite sheet.

[0005] Preferably, the mounting groove is concentric with the substrate to ensure that the diamond layer is concentric with the substrate and to ensure uniform wear of the diamond layer.

[0006] Preferably, the top edge of the substrate is provided with a chamfer to increase the space for filling the brazing filler and improve the brazing connection strength.

[0007] Preferably, the bottom edge of the substrate is chamfered, which increases the convenience of embedding the polycrystalline diamond composite sheet into the drill body of the drill bit, and increases the space for filling brazing filler, thereby improving the brazing connection strength.

[0008] A gauge-maintaining drill bit including the aforementioned polycrystalline diamond composite sheet further includes a drill bit body, a cutting composite sheet A, and a cutting composite sheet B. Several mounting blocks are distributed circumferentially along the top edge of the drill bit body. The polycrystalline diamond composite sheet is mounted on the outer side of the mounting blocks to achieve gauge maintenance. The cutting composite sheet A is obliquely mounted on one side edge of the top of the mounting blocks to achieve the effect of cutting the outer soil blocks. Several mounting posts extend upwards and outwards from the top center of the drill bit body. The cutting composite sheet B is obliquely positioned at the top of the mounting posts to achieve the effect of cutting the central soil block. The cutting composite sheet B is positioned lower than the cutting composite sheet A, so that the outer soil block is cut before the central soil block. The cutting composite sheets A and B are oriented in the same direction to ensure that both the outer and central soil blocks can be cut.

[0009] Preferably, the mounting columns are positioned between adjacent mounting blocks so that the central soil block can be discharged along the gap between the adjacent mounting blocks.

[0010] Preferably, a guide ramp is provided on the other side of the top of the mounting block to guide the cut outer soil block.

[0011] Furthermore, a guide cone surface is provided between adjacent mounting blocks to guide the cut soil blocks.

[0012] Furthermore, the lower middle part of the drill bit body is provided with a cavity; the guide cone surface is provided with a guide hole that communicates with the cavity; the guide hole introduces the chopped soil into the cavity for soil discharge.

[0013] Furthermore, the lower part of the cavity is provided with internal threads for connection to the outside.

[0014] Furthermore, the guide hole is set perpendicular to the guide cone surface to facilitate guiding the chopped soil blocks.

[0015] The beneficial effects of the present invention are as follows: The polycrystalline diamond composite sheet of the present invention has the following advantages: (1) The top edge of the substrate of the present invention replaces the existing diamond layer and is brazed to the drill bit body, thereby avoiding gaps between the polycrystalline diamond composite sheet and the drill bit body and reducing the probability of chipping at the top edge of the polycrystalline diamond composite sheet; (2) The chamfer A of the present invention increases the space for filling brazing filler and improves the brazing connection strength; the chamfer B increases the convenience of embedding polycrystalline diamond composite sheet into the drill body of the drill bit on the one hand, and increases the space for filling brazing filler on the other hand, thus improving the brazing connection strength.

[0016] Gauge-maintaining drill bits have the following advantages: (1) The gauge-maintaining drill bit of the present invention can improve service life; (2) The guide cone of the present invention guides the soil block after it has been cut. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of an existing gauge-maintaining drill bit; Figure 2 This is a perspective view of the polycrystalline diamond composite sheet of the present invention; Figure 3 yes Figure 2 Top view; Figure 4 yes Figure 3 AA section view; Figure 5 This is a perspective view of the gauge-maintaining drill bit of the present invention; Figure 6 yes Figure 5 The main view; Figure 7 yes Figure 6 BB cross-sectional view; Figure 8 yes Figure 6 CC section view; In the diagram: 01. Cutting composite sheet, 02. Gauge-maintaining composite sheet, 11. Diamond layer, 12. Matrix, 121. Insertion groove, 122. Chamfer A, 123. Chamfer B, 2. Drill bit body, 21. Mounting block, 22. Mounting post, 23. Guide cone surface, 231. Guide hole, 24. Cavity, 25. Guide slope, 3. Cutting composite sheet A, 4. Cutting composite sheet B. Detailed Implementation

[0018] Example 1: See Figure 2-4 A polycrystalline diamond composite sheet includes an integral diamond layer 11 and a substrate 12. The diamond layer 11 and the substrate 12 are formed by high-pressure and high-temperature sintering. The top center of the substrate 12 is provided with an insert groove 121 that matches the diamond layer 11, which is used to hold the diamond powder that forms the diamond layer 11. After the diamond powder enters the insert groove 121, it is sintered under high temperature and high pressure to form a state in which the diamond layer 11 is embedded in the insert groove 121. The top surface of the diamond layer 11 does not exceed the opening of the insert groove 121. The top edge of the substrate 12 is brazed to the drill bit body 2 instead of the existing diamond layer 11, so as to avoid gaps between the polycrystalline diamond composite sheet and the drill bit body 2 and reduce the probability of chipping at the top edge of the polycrystalline diamond composite sheet.

[0019] Compared with the prior art, the present invention uses the top edge of the substrate 12 to replace the existing diamond layer 11 and braze it to the drill bit body 2, thereby avoiding gaps between the polycrystalline diamond composite sheet and the drill bit body 2 and reducing the probability of chipping at the top edge of the polycrystalline diamond composite sheet.

[0020] The top edge of the substrate 12 is provided with a chamfered edge 122 to increase the space for filling the brazing filler and improve the brazing connection strength.

[0021] The bottom edge of the substrate 12 is provided with a chamfer 123, which on the one hand increases the convenience of embedding the polycrystalline diamond composite sheet into the drill bit body 2, and on the other hand increases the space for filling brazing filler, thereby improving the brazing connection strength.

[0022] The working principle of this embodiment is as follows: The top edge of the substrate 12 replaces the existing diamond layer 11 and is brazed to the drill bit body 2, avoiding gaps between the polycrystalline diamond composite sheet and the drill bit body 2, and reducing the probability of chipping at the top edge of the polycrystalline diamond composite sheet; chamfer A 122 increases the space for filling brazing filler and improves the brazing connection strength; chamfer B 123 increases the convenience of embedding the polycrystalline diamond composite sheet into the drill bit body 2 on the one hand, and increases the space for filling brazing filler on the other hand, thus improving the brazing connection strength.

[0023] Example 2: Example 2 is basically the same as Example 1, and the similarities will not be repeated. The difference is that the mounting groove 121 is concentric with the substrate 12, which can ensure that the diamond layer 11 is concentric with the substrate 12 and ensure that the diamond layer 11 is worn evenly.

[0024] Example 3, see Figure 5-8 A gauge-maintaining drill bit including the polycrystalline diamond composite sheet described in Embodiment 1 further includes a drill bit body 2, a cutting composite sheet A 3, and a cutting composite sheet B 4; a plurality of mounting blocks 21 are distributed circumferentially along the top edge of the drill bit body 2; the polycrystalline diamond composite sheet is mounted on the outer side of the mounting block 21 to achieve the gauge-maintaining effect; the cutting composite sheet A 3 is obliquely mounted on one side edge of the top of the mounting block 21 to achieve the effect of cutting the outer soil block; a plurality of mounting posts 22 extend upward and outward from the top center of the drill bit body 2; the cutting composite sheet B 4 is obliquely set at the top of the mounting post 22 to achieve the effect of cutting the central soil block; the cutting composite sheet B 4 is set lower than the cutting composite sheet A 3, so that the outer soil block is cut before the central soil block; the cutting composite sheet A 3 and the cutting composite sheet B 4 are oriented in the same direction to ensure that both the outer soil block and the central soil block can be cut.

[0025] The mounting column 22 is positioned between adjacent mounting blocks 21 so that the central soil block can be discharged through the gap between the adjacent mounting blocks 21.

[0026] The top of the mounting block 21 has a guide slope 25 on the other side to guide the cut outer soil block.

[0027] A guide cone surface 23 is provided between adjacent mounting blocks 21 to guide the cut soil blocks.

[0028] The lower middle part of the drill bit body 2 is provided with a cavity 24; the guide cone surface 23 is provided with a guide hole 231 that communicates with the cavity 24; the guide hole 231 introduces the chopped soil into the cavity 24 for soil discharge.

[0029] The lower part of cavity 24 is provided with internal threads for connection with the outside.

[0030] The guide hole 231 is set perpendicular to the guide cone surface 23 to facilitate the guidance of the chopped soil blocks.

[0031] The cavity 24 is concentrically set with the base 12 to ensure that the shredded soil blocks enter the cavity 24 evenly.

Claims

1. A polycrystalline diamond composite sheet, comprising an integral diamond layer and a matrix; characterized in that, The top center of the substrate has an insert groove that matches the diamond layer; the diamond layer is embedded in the insert groove; the top surface of the diamond layer does not extend beyond the opening of the insert groove.

2. The polycrystalline diamond composite sheet according to claim 1, characterized in that: The top edge of the base is provided with a chamfered edge.

3. The polycrystalline diamond composite sheet according to claim 1 or 2, characterized in that: The bottom edge of the substrate is chamfered.

4. A gauge-maintaining drill bit comprising the polycrystalline diamond composite sheet as described in claim 3, characterized in that: It also includes a drill bit body, cutting composite plate A, and cutting composite plate B; several mounting blocks are distributed around the top edge of the drill bit body; polycrystalline diamond composite plates are installed on the outer side of the mounting blocks; cutting composite plate A is installed obliquely on one side edge of the top of the mounting blocks; several mounting posts extend upward and outward from the top center of the drill bit body; cutting composite plate B is obliquely set at the top of the mounting posts; cutting composite plate B is set lower than cutting composite plate A; cutting composite plate A and cutting composite plate B face the same direction.

5. The gauge-maintaining drill bit according to claim 4, characterized in that: The mounting posts are positioned between adjacent mounting blocks.

6. The gauge-maintaining drill bit according to claim 4, characterized in that: A guide ramp is provided on the other side of the top of the mounting block.

7. The gauge-maintaining drill bit according to claim 5, characterized in that: A guide cone surface is provided between adjacent mounting blocks.

8. The gauge-maintaining drill bit according to claim 7, characterized in that: The lower middle part of the drill bit body has a cavity; the guide cone surface has a guide hole that communicates with the cavity.

9. The gauge-maintaining drill bit according to claim 8, characterized in that: The lower part of the cavity is provided with internal threads.

10. The gauge-maintaining drill bit according to claim 8, characterized in that: The guide hole is set perpendicular to the guide cone surface.

Images