Multilayer self-outlet diamond compact and drill bit

Abstract

The utility model discloses a multilayer self-out blade diamond compact and drill bit, including polycrystalline diamond layer and hard alloy base body, polycrystalline diamond layer sets up on hard alloy base body, the end face of polycrystalline diamond layer is cutting face, at least two cutting edges are provided on the cutting face, at least two cutting edges are arranged along the drilling direction interval, and the hierarchical cutting structure of at least two cutting levels is formed, when the cutting level abrasion failure of the preceding stage is, the cutting level automatic exposure of the latter stage forms new main cutting edge. The compact of the utility model is through the unique hierarchical design, and the effective working life of compact is greatly prolonged, and the tripping frequency caused by the frequent replacement of drill bit is reduced, thereby the pure drilling time and overall operation efficiency are improved significantly.

Description

Technical Field

[0001] This utility model relates to the field of superhard composite material technology, specifically to a multi-layer self-evolving diamond composite sheet and drill bit. Background Technology

[0002] Polycrystalline diamond composite (PDC) sheets, as a novel type of superhard composite material, possess remarkable characteristics such as high hardness, high wear resistance, and excellent impact resistance. Compared to traditional cemented carbide materials, they exhibit superior wear resistance and mechanical properties, thus finding widespread application in drilling tools. Since the 1970s, PDC drill bits have been gradually applied in the oil and gas extraction field. With continuous advancements in materials technology and drill bit design, their share in the global drilling market has steadily increased, making them an indispensable key tool component in current drilling operations.

[0003] Global oil and gas exploration and development activities are continuously advancing into deeper and more complex formations. As drilling depths increase, the encountered formations become increasingly dense and hard, significantly reducing drillability. This phenomenon has become a key factor restricting the efficiency and cost of deep and ultra-deep drilling. Against this backdrop, polycrystalline diamond composite (PDC) drill bits, with their long lifespan and high-efficiency rock-breaking capabilities, are increasingly relied upon in oil and gas exploration due to their excellent wear resistance, impact resistance, and stable drilling performance, and have gradually become the preferred drill bit type in this field. To further improve the efficiency and economy of deep formation drilling, continuous optimization of the structure and material properties of PDC drill bits has become an urgent need for technological development in the industry.

[0004] In current deep and ultra-deep drilling operations, polycrystalline diamond composite (PDC) drill bits are the core rock-breaking tools. During continuous drilling, their cutting teeth inevitably experience problems such as cutting edge wear and dulling due to interaction with hard and highly abrasive formations. This leads to a significant decrease in the rock-breaking efficiency of the drill bit, a reduction in drilling speed, and a direct impact on overall drilling efficiency and cost.

[0005] Currently, the conventional approach to addressing the wear and failure of PDC cutting teeth mainly involves replacing the drill bit or the composite cutting tool itself. This process requires repeated tripping in and out of the drill bit, significantly increasing non-productive time and raising the labor, equipment, and material costs of drilling operations. Therefore, to address the pain points of existing PDC drill bits—short lifespan and frequent replacements in long well sections and difficult formations—it is urgent to conduct innovative design and performance optimization of the traditional PDC structure and its arrangement on the drill bit to improve its wear resistance, self-sharpening properties, and overall drilling economy. Utility Model Content

[0006] To address the technical problems existing in the prior art, the purpose of this utility model is to provide a multi-layer self-exposing diamond composite sheet and drill bit. The composite sheet adopts a multi-stage cutting structure design. When the primary cutting edge is worn down during drilling, there is no need to lift the drill. Its preset secondary or even multiple backup cutting edges will automatically take over and emerge, forming a new sharp working edge. This maintains continuous and efficient rock-breaking ability in complex formations and significantly reduces the number of tripping operations.

[0007] The objective of this utility model is achieved through the following technical solution: a multi-layer self-exposing diamond composite sheet, comprising a polycrystalline diamond layer and a cemented carbide substrate, wherein the polycrystalline diamond layer is disposed on the cemented carbide substrate, the end face of the polycrystalline diamond layer is a cutting surface, and at least two cutting edges are disposed on the cutting surface, wherein the at least two cutting edges are arranged at intervals along the drilling direction to form a hierarchical cutting structure with at least two cutting levels; when the cutting level in the preceding level wears and fails, the cutting level in the subsequent level automatically exposes to form a new main cutting edge.

[0008] Specifically, the cutting edge is arc-shaped, and each cutting edge arches out in the same direction along the drilling direction.

[0009] Furthermore, the cutting surface is a plane; or, the cutting surface protrudes along the central axis and slopes downwards to both sides, the central axis extending along the drilling direction, so that the cutting edge has a ridge-like structure.

[0010] Furthermore, the top of the side of the cutting edge facing the drilling direction is provided with a chamfer, the size of which is 0.3-1 mm.

[0011] Specifically, an arc-shaped groove is formed between adjacent cutting edges. The longitudinal section of the arc-shaped groove is U-shaped, with a groove width of 1-5 mm and a groove depth of 0.5-2 mm.

[0012] Preferably, the spacing between adjacent cutting edges is 1.5-5 mm; the number of cutting edge layers is 2-6.

[0013] Furthermore, the cutting edge is formed by one of the following processes: laser engraving, grinding, or electrical discharge machining.

[0014] Specifically, the cemented carbide substrate is a tungsten-cobalt cemented carbide, and the thickness of the polycrystalline diamond layer is 0.5-5 mm.

[0015] This utility model provides another technical solution to solve the technical problem: a drill bit, including a drill bit body, wherein the crown of the drill bit body is provided with multiple blades, and each blade is provided with multiple multi-layer self-ejecting diamond composite sheets.

[0016] Compared with the prior art, the present invention has at least the following beneficial effects:

[0017] 1. This utility model's composite cutting edge, through a unique layered design, has multiple cutting edges located on the same surface. When the surface polycrystalline diamond (PDC) edge becomes dull, the sharper cutting edge below can be exposed in time to take over, achieving a "self-sharpening" function for the cutting unit. This fundamentally overcomes the drawback of traditional PDC drill bits where a single point failure results in overall scrapping, significantly extending the effective working life of the composite cutting edge, reducing the number of trips and starts due to frequent drill bit changes, and thus significantly improving the drill bit's pure drilling time and overall operating efficiency.

[0018] 2. The self-extracting cutting edge structure of this utility model can ensure that there is always a sharp cutting edge participating in rock breaking throughout the entire life cycle, thereby maintaining the relative stability of the mechanical drilling speed, avoiding a precipitous drop in drilling efficiency, and ensuring the continuity and stability of drilling operations.

[0019] 3. The composite sheet of this utility model adopts a "ridge tooth" structure, which can effectively disperse the impact force to multiple directions, greatly reduce local stress concentration, and effectively prevent the composite sheet from chipping. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of Example 1.

[0021] Figure 2 This is a front view of the cutting surface in Example 1.

[0022] Figure 3 for Figure 2 AA sectional view.

[0023] Figure 4 This is a schematic diagram of the structure of Example 2.

[0024] Figure 5 This is a front view of the cutting surface in Example 2.

[0025] Figure 6 This is a side view of Example 2.

[0026] Figure 7 This is a schematic diagram of the structure of Example 3.

[0027] Figure 8 This is a front view of the cutting surface in Example 3.

[0028] Figure 9 for Figure 8 BB cross-sectional view.

[0029] Figure 10 This is a schematic diagram of the structure of Example 4.

[0030] Figure 11 This is a side view of Example 4.

[0031] Figure 12 This is a schematic diagram of the structure of Example 5.

[0032] Figure 13 This is a diagram showing the working state of the drill bit in Example 3.

[0033] In the picture:

[0034] 100 / 200 / 300 / 400 - Multi-layer self-evolving diamond composite sheet; 10 / 20 - Polycrystalline diamond layer; 11 / 21 / 31 / 41 - Cutting surface; 110 / 210 / 310 / 410 - Cutting edge; 113 / 213 - Chamfer; 215 - Protrusion; 120 / 220 - Arc groove; 60 - Carbide matrix;

[0035] 900 - Drill bit; 90 - Drill bit body; 91 - Cutting blade. Detailed Implementation

[0036] To facilitate understanding of this utility model, the technical solutions and advantages of the utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Any mechanisms or methods not elaborated in this utility model can be referred to in the prior art. The specific structure and features of this utility model are illustrated below by way of example and should not constitute any limitation on this utility model. Furthermore, any technical feature mentioned below (including implicit or disclosed features), as well as any technical feature directly shown or implied in the figures, can be arbitrarily combined or deleted among these technical features to form more other embodiments that may not be directly or indirectly mentioned in this utility model. The accompanying drawings show preferred embodiments of this utility model. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this utility model.

[0037] Example 1

[0038] like Figure 1-3 As shown, the multilayer self-cutting diamond composite sheet 100 of this embodiment 1 includes a polycrystalline diamond layer 10 and a cemented carbide substrate 60. The polycrystalline diamond layer 10 is disposed on the cemented carbide substrate 60, and the end face of the polycrystalline diamond layer 10 is the cutting surface 11.

[0039] The polycrystalline diamond layer 10 has a planar cutting surface 11 with three cutting edges 110 arranged at intervals along the drilling direction, forming a hierarchical cutting structure with three cutting levels. When the cutting level in the preceding level wears out, the cutting level in the following level automatically emerges to form a new main cutting edge 110.

[0040] Specifically, the cutting edges 110 are arc-shaped, with all three cutting edges 110 arching out in the same direction along the drilling direction. Each cutting edge 110 has a chamfer 113 at the top of its side facing the drilling direction, with a chamfer size of 0.3-1 mm. The chamfer 113 ensures both the self-sharpening ability of the cutting edges 110 during operation and its grinding capacity and operational efficiency.

[0041] Furthermore, a gap of 1.5-5 mm is maintained between adjacent cutting edges 110. An arc-shaped groove 120 is formed between adjacent cutting edges 110. The longitudinal section of the arc-shaped groove 120 is U-shaped, with a groove width of 1-5 mm and a groove depth of 0.5-2 mm. The sufficient width and depth of the arc-shaped groove 120 effectively ensure the effective working area of ​​the cutting edges 110, improving its drilling efficiency.

[0042] Furthermore, the cutting edges 110 at each level are formed in the polycrystalline diamond layer 10 by one of the processes of laser engraving, grinding or electrical discharge machining.

[0043] The cemented carbide substrate 60 is a tungsten-cobalt cemented carbide, preferably YG6, YG8, YG11, YG13, or YG15. The polycrystalline diamond layer 10 has a thickness of 0.5-5 mm, which ensures grinding performance while achieving cost savings.

[0044] Example 2

[0045] like Figure 4-6 As shown, the multilayer self-cutting diamond composite sheet 200 of this embodiment 2 includes a polycrystalline diamond layer 20 and a cemented carbide substrate. The polycrystalline diamond layer 20 is disposed on the cemented carbide substrate, and the end face of the polycrystalline diamond layer 20 is the cutting surface 21.

[0046] In this embodiment 2, the multi-layer self-emerging diamond composite sheet has a "roof tooth" structure. The cutting surface 21 of the polycrystalline diamond layer 20 protrudes 215 along the central axis and slopes downwards to both sides, with the central axis extending along the drilling direction. Three cutting edges 210 are provided on the cutting surface 21, and these three cutting edges 210 are arranged at intervals along the drilling direction to form a hierarchical cutting structure with three cutting levels. When the cutting level at the previous level wears out and fails, the cutting level at the next level automatically emerges to form a new main cutting edge 210.

[0047] Specifically, the cutting edge 210 is arc-shaped as a whole, with all three cutting edges 210 arching out in the same direction along the drilling direction. Furthermore, the cutting edge 210 forms a ridge-like structure with a central protrusion and sloping downwards at both ends, following the shape of the cutting surface 21. The ridge-like structure of the cutting edge 210 effectively disperses the impact force in multiple directions, greatly reducing local stress concentration and effectively preventing tooth breakage of the composite sheet.

[0048] Furthermore, each cutting edge 210 has a chamfer 213 on the top of its side facing the drilling direction. There is a gap between adjacent cutting edges 210, and an arc-shaped groove 220 is formed between adjacent cutting edges 210. The longitudinal section of the arc-shaped groove 220 is U-shaped.

[0049] The other structures and parameters are the same as in Example 1.

[0050] Example 3

[0051] like Figure 7-9 As shown, the multi-layer self-ejecting diamond composite sheet 300 of this embodiment 3 has a structure that is basically the same as that of embodiment 1. The difference is that six cutting edges 310 are provided on the cutting surface 31 of embodiment 3. The six cutting edges 310 are arranged at intervals along the drilling direction to form a hierarchical cutting structure with six cutting levels, which makes the overall shape of the multi-layer self-ejecting diamond composite sheet 300 of embodiment 3 elongated along the drilling direction.

[0052] Example 4

[0053] like Figure 10-11 As shown, the multi-layer self-ejecting diamond composite sheet 400 of this embodiment 4 has a structure that is basically the same as that of embodiment 2. The difference is that six cutting edges 410 are provided on the cutting surface 41 of embodiment 4. The six cutting edges 410 are arranged at intervals along the drilling direction to form a hierarchical cutting structure with six cutting levels, which makes the overall shape of the multi-layer self-ejecting diamond composite sheet 400 of embodiment 4 elongated along the drilling direction.

[0054] Example 5

[0055] like Figure 12-13 As shown, the drill bit 900 of this embodiment 5 includes a drill bit body 90. The crown of the drill bit body 90 is circumferentially surrounded by multiple blades 91 at equal angles. Each blade 91 is provided with multiple multi-layer self-ejecting diamond composite sheets 200 of embodiment 2.

[0056] Compared with existing technologies, this utility model's multi-layer self-sharpening diamond composite sheet, through its unique layered design, allows the sharp cutting edge of the lower layer to be exposed and take over the work promptly when the surface polycrystalline diamond becomes dull, thus achieving the "self-sharpening" function of the cutting unit. This fundamentally overcomes the drawback of traditional PDC drill bits where a single point failure results in the entire bit being scrapped, significantly extending the effective working life of the composite sheet, reducing the number of trips and starts caused by frequent drill bit changes, and thus significantly improving the drill bit's pure drilling time and overall operating efficiency.

[0057] The above embodiments are merely preferred embodiments of the present utility model and should not be construed as limiting the scope of protection of the present utility model. For those skilled in the art, it will be understood that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present utility model. The scope of the present utility model is defined by the appended claims and their equivalents.

Claims

1. A multilayer self-ejecting diamond composite sheet, comprising a polycrystalline diamond layer and a cemented carbide substrate, wherein the polycrystalline diamond layer is disposed on the cemented carbide substrate, characterized in that, The end face of the polycrystalline diamond layer is the cutting surface, and at least two cutting edges are provided on the cutting surface. The at least two cutting edges are arranged at intervals along the drilling direction to form a hierarchical cutting structure with at least two cutting levels. When the cutting level in the preceding level wears out and fails, the cutting level in the following level automatically emerges to form a new main cutting edge.

2. The multilayer self-ejecting diamond composite sheet as described in claim 1, characterized in that, The cutting edge is arc-shaped, and each cutting edge arches out in the same direction along the drilling direction.

3. The multilayer self-ejecting diamond composite sheet as described in claim 2, characterized in that, The cutting surface is a plane; or, the cutting surface protrudes along the central axis and slopes downwards to both sides, the central axis extending along the drilling direction, so that the cutting edge has a ridge-like structure.

4. The multilayer self-ejecting diamond composite sheet as described in claim 2, characterized in that, The top of the side of the cutting edge facing the drilling direction is chamfered, and the chamfer has a size of 0.3-1 mm.

5. The multilayer self-ejecting diamond composite sheet as described in claim 2, characterized in that, An arc-shaped groove is formed between adjacent cutting edges. The longitudinal section of the arc-shaped groove is U-shaped, with a groove width of 1-5 mm and a groove depth of 0.5-2 mm.

6. The multilayer self-ejecting diamond composite sheet as described in claim 5, characterized in that, The spacing between adjacent cutting edges is 1.5-5mm.

7. The multilayer self-ejecting diamond composite sheet as described in claim 1, characterized in that, The number of cutting edge layers is 2-6.

8. The multilayer self-ejecting diamond composite sheet as described in claim 1, characterized in that, The cutting edge is formed by one of the following processes: laser engraving, grinding, or electrical discharge machining.

9. The multilayer self-ejecting diamond composite sheet as described in claim 1, characterized in that, The cemented carbide substrate is a tungsten-cobalt cemented carbide, and the thickness of the polycrystalline diamond layer is 0.5-5 mm.

10. A drill bit, characterized in that, The drill bit body includes a crown portion having multiple blades, each blade having multiple multi-layer self-ejecting diamond composite sheets as described in any one of claims 1-9.

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