CN111236851A - Long-life module cutting tooth and PDC drill bit adopting same - Google Patents

Abstract

The invention discloses a long-life module cutting tooth and a PDC drill bit adopting the cutting tooth, comprising a bit body, blades, a water hole and the cutting tooth; the cutting teeth are fixedly connected on the blade, and at least one cutting tooth is a module tooth consisting of a central tooth, a shaft sleeve and an elastic element; the center tooth comprises diamond layer and base member, its characterized in that: the diamond layer end face is circumferentially distributed with 3D ratchet teeth, and an elastic element and a limiting device are arranged between the central teeth and the shaft sleeve. When the PDC drill bit breaks rock and creeps into, on one hand, the cutting load can push the central tooth to rotate in the circumferential direction through the 3D ratchet teeth, and on the other hand, the cutting load and the elastic element can also form elastic interaction. The beneficial effects are as follows: the elastic element can play a role in buffering and absorbing vibration, and prevent the diamond layer from being damaged by overload impact; the 3D ratchet characteristics of the diamond layer can break rock in a plough mode, and the drilling energy efficiency of a drill bit is improved; the circumferential rotation capacity of the central tooth can also enable the cutting edge to be worn uniformly, and the service life of the drill bit is greatly prolonged.

Description

Long-life module cutting tooth and PDC drill bit adopting same

Technical Field

The invention belongs to the technical field of oil and gas drilling engineering, mining engineering, geological drilling, tunnel engineering, hydrology and the like, and particularly relates to a long-life module cutting tooth with a buffering and vibration absorbing structure and a PDC drill bit adopting the cutting tooth.

Background

A drill bit is a tool that directly contacts rock during drilling and breaks the rock by cutting, impacting, etc.

PDC (Polycrystalline Diamond Compact) bits, which are an important type of prior art bits, are increasingly used in drilling, geological and architectural engineering. The PDC drill bit breaks rock in a cutting mode, and under the ideal working condition that the center line of the drill bit is coincident with the center line of a well hole, the cutting track generated by the cutting teeth on the PDC drill bit at the bottom of the well is a concentric circular ring belt. With conventional PDC bits, the cutting teeth become progressively dull due to thermal wear as the cutting teeth continue to scrape the rock during the rock breaking process, causing continuous friction between the rock and the bit. At the initial stage of drilling of the drill bit, the abrasion loss of cutting teeth is small, the contact area of tooth edges and rocks is small, the cutting specific pressure is large, and the mechanical drilling speed is high; and as the abrasion loss is gradually increased, the contact area between the tooth edge and the rock is increased, the specific pressure is reduced, and the mechanical drilling speed is gradually reduced until the drill bit fails. Furthermore, the harder the formation rock, the more difficult it is for the cutter to penetrate the rock, and maintaining effective penetration of the cutter into the rock downhole is a necessary condition for the PDC bit to break up the rock efficiently. In order to improve the invasion capacity of the PDC drill bit to the rock, the drill bit usually adopts cutting teeth with smaller diameters, but the abrasion speed of the cutting teeth is high when the drill bit drills in a hard formation, and the abrasion height of the cutting teeth with the smaller diameters is smaller, so that a technical contradiction which is not easy to overcome in the design of the hard formation drill bit is formed, and the working capacity of the hard formation drill bit is severely restricted. Therefore, avoiding the constant scraping of rock by the cutting teeth, and thereby reducing thermal wear, is an important approach to improving the drilling efficiency and extending the life of drill bits, particularly drill bits that operate in high hardness, highly abrasive formations.

U.S. Pat. No. 5, 20140326515, 1 discloses a rotary CUTTING tooth FOR PDC BITS. The rotary cutter of this patent has a separate bearing structure that allows it to rotate relative to the blade body after it is mounted on the bit blade. Through set up the rotary teeth on the wing, make the drill bit when cutting the stratum the whole circumference homoenergetic of the cutting end face of rotary teeth can participate in the cutting to the stratum, improved its cutting end face's utilization ratio to improve the life of drill bit by a wide margin, showing the footage ability that has improved single drill bit, and keep higher drill bit drilling speed. However, during operation of PDC bits, the cutters are typically impacted by the rock due to the formation environment and the complexity of the rock breaking process. Due to the diameter limitation of a single rotary cutting tooth, the structural size is inevitably small, and the strength is not high, so that the impact resistance of the cutting tooth is poor, and the cutting tooth is easy to break under impact load.

When the drill encounters a stratum containing gravels or the stratum is soft and hard in a staggered manner and changes frequently, the impact load borne by the composite sheet is large, and the diamond composite sheet is easy to have non-abrasion abnormal failures such as tooth breakage, delamination and tooth breakage, so that the whole drill bit fails. The impact resistance of the existing diamond compact is mainly improved by changing the interface structure of a diamond layer and a hard alloy base shaft sleeve in the diamond compact to reduce the residual stress of the diamond layer or changing the material formula and the processing technology. The PDC teeth with the special-shaped structures have the advantages that although the impact resistance is improved, the phenomena of large drilling and cutting resistance, large torque of a drill bit, low drilling efficiency and the like exist in the using process.

Disclosure of Invention

The invention aims to provide the following technical scheme: aiming at the defects of the conventional cutting teeth, the long-life modular cutting teeth with the vibration buffering and absorbing capability and the PDC drill bit adopting the cutting teeth are provided, wherein the long-life modular cutting teeth with the vibration buffering and absorbing structure are hereinafter referred to as the modular teeth. The special-shaped structure diamond composite sheet layer of the module tooth can push the cutting tooth to realize regular rotation, so that all cutting edges of the cutting tooth participate in rock cutting, and meanwhile, the special-shaped cutting edges break rock in a plough mode.

The technical scheme adopted by the invention is as follows:

a long-life module cutting tooth and a PDC drill bit adopting the cutting tooth comprise a drill bit body, blades, water holes and cutting teeth, wherein the blades extend from the drill bit body, and the drill bit body at the bottoms of the blades is provided with the through water holes; the cutting teeth are fixedly connected to the blade, wherein part or all of the cutting teeth are module teeth consisting of a central tooth, a shaft sleeve and an elastic element; the central tooth is composed of a diamond layer and a basal body. The method is characterized in that: the end face of the diamond layer is circumferentially provided with 3D ratchet teeth, an elastic element and a limiting device are arranged between the central tooth and the shaft sleeve, and the module tooth is fixedly connected to a blade of the PDC drill bit.

In the technical solution explained in the present invention, the center tooth has two degrees of freedom, namely: an axial translational degree of freedom along the central tooth axis and a rotational degree of freedom about the central tooth axis. The invention has the following beneficial effects:

1. during the rock breaking and drilling process of the PDC drill bit, the cutting load drives the asymmetric 3D ratchet teeth on the diamond layer of the central tooth to enable the central tooth to generate torque relative to the base, and therefore unidirectional rotation motion is generated. The cutting edges of the diamond layer can participate in cutting and rock breaking within the range of 360 degrees, and the wear resistance and the service life of the cutting teeth are greatly improved.

2. And under the action of cutting load, the elastic element makes the central tooth and the drill bit body elastically interact. Especially when drilling inhomogeneous strata or drilling parameters have large fluctuation, the vibration absorber can play a role in buffering and absorbing vibration. The impact resistance of the cutting teeth is greatly improved, so that the occurrence of abnormal failure accidents such as tooth breakage, chipping or tooth breakage of the cutting teeth is slowed down.

3. The 3D ratchet of the module teeth can contact the rock at a "point" to break the rock in a plowing manner. Has the advantages of strong invasion capacity, high rock breaking efficiency, small breaking specific work and the like.

4. The central tooth base body is in clearance fit with the gear hole of the base shaft sleeve through a rotating shaft on the central tooth base body to form rotary connection, the bearing structure of the central tooth base body can be in a shaft body type, and the vibration reduction rotary teeth are directly arranged on a drill bit; or may be free standing, in the form of a sliding bearing, with the base sleeve now acting as a bearing sleeve. The whole cutting tooth is taken as a whole, has simple structure and is convenient to process.

Optionally, the elastic element is a disc spring, the 3D serrated ratchet teeth are distributed on the end face of the diamond layer along the circumferential direction, and the limiting device arranged between the central tooth and the shaft sleeve is a snap spring or a semicircular key.

The disc spring is used as an elastic element, so that proper elastic rigidity can be provided for the central tooth; the 3D serrated ratchet has an asymmetric structure, can generate a rotation torque under the action of cutting load and pushes the central tooth to rotate; the clamp spring and the semicircular key can be used as a simple and reliable limiting device in the technical scheme of the invention.

As a further option, the sleeve is of a through-hole configuration, the resilient element is disposed at one end adjacent the diamond layer, and the stop means is disposed at the other end opposite the diamond layer.

The technical scheme has the advantages of simple structure, convenient assembly and disassembly and strong practicability.

Alternatively, the elastic element is a disc spring, or rubber, or a high-elasticity metal body, or a composite material with elasticity, or a combination of at least two of the above.

There is also a large difference in the cutting loads generated when the PDC bit drills into different formation rock strengths. In order to further improve the application condition of the technology, various elastic element technical schemes are provided to obtain the buffering and vibration absorbing capability in different load amplitude ranges.

As a further alternative, the elastic element consists of a disc spring and rubber, and the two are arranged in parallel or in series.

The elastic elements made of two different materials can provide a combined type step vibration reduction effect with better comprehensive performance for the central gear. For example, when the PDC drill bit continuously drills into different soft and hard stratums, the elastic element with smaller elastic rigidity plays a main role when a softer stratum breaks rock, and the elastic element with larger elastic rigidity plays a main role when a harder stratum breaks rock.

Optionally, a seal ring is further disposed between the central tooth and the shaft sleeve.

The drill bit is complicated in underground working environment, various solid-phase particles are suspended in drilling fluid, if the drill bit enters a rotary contact surface between the shaft sleeve and the central tooth base body, abrasive particle abrasion and damage of a rotary pair are easily caused, the relative motion resistance of the rotary pair is increased, so that the rotary pair cannot rotate and the elastic buffering capacity is lost, the service lives of the cutting teeth and the drill bit are influenced, and therefore a sealing ring is arranged between the central tooth and the shaft sleeve.

Alternatively, a rolling bearing is also provided between the central gear and the shaft sleeve.

The rolling bearing structure is arranged, and aims to reduce the friction resistance between the central tooth and the shaft sleeve and enable the central tooth to rotate more flexibly.

Optionally, the 3D ridges are distributed on the diamond layer in an inward concave manner or an outward convex manner towards the center direction.

The 3D ratchet is designed to be concave or convex, a flexible design scheme can be provided for the module teeth, and the broken rock can be invaded and scraped according to more personalized cutting parameters.

Alternatively, the module teeth are fixedly connected with the blades through bolts.

The module teeth and the blades are fixedly connected together in a bolt connection mode, and the blade has the characteristics of convenience in disassembly and assembly, simplicity in manufacturing process, convenience in replacement or maintenance and the like.

Alternatively, the PDC drill bit is a drill bit having diamond-based cutting teeth, such as a conventional PDC drill bit, a disc cutter type drill bit, a PDC-disc cutter composite drill bit, or a PDC-cone composite drill bit.

The technical scheme provided by the invention aims to provide a polycrystalline diamond compact (PDC tooth) structure with high efficiency and long service life, so that the PDC tooth can be used as a drill bit of a cutting element.

Drawings

The invention will be described by way of specific embodiments and with reference to the accompanying drawings in which:

fig. 1 is a structural composition diagram of a first embodiment of the present invention.

Fig. 2 is a schematic view of the working principle of the circumferential rotation driving in the first embodiment of the present invention.

Fig. 3 is a schematic view of an axial elastic buffer according to a first embodiment of the present invention.

Fig. 4 is a schematic structural diagram of a second embodiment of the present invention.

Fig. 5 is a schematic structural diagram of a third embodiment of the present invention.

FIG. 6 is a structural diagram of a fourth embodiment of the present invention.

FIG. 7 is a structural diagram of a fifth embodiment of the present invention.

FIG. 8 is a structural diagram of a sixth embodiment of the present invention.

FIG. 9 is a structural diagram of a seventh embodiment of the present invention.

FIG. 10 is a sectional view taken along the line A-A in FIG. 9.

Fig. 11 is a structural diagram of an eighth embodiment of the present invention.

FIG. 12 is a structural diagram of a ninth embodiment of the present invention.

Fig. 13 is a structural diagram of a tenth embodiment of the present invention.

FIG. 14 is a graph showing the relationship between "deformation and load" in the tenth embodiment of the present invention.

FIG. 15 is a structural diagram of an eleventh embodiment of the present invention.

FIG. 16 is a structural diagram of a twelfth embodiment of the present invention.

Fig. 17 is a right side view of fig. 16.

FIG. 18 is a structural diagram of a thirteenth embodiment of the present invention.

FIG. 19 is a structural diagram of a fourteenth embodiment of the invention.

Fig. 20 is a structural composition diagram of a fifteenth embodiment of the invention.

Fig. 21 is a structural diagram of a sixteenth embodiment of the present invention.

FIG. 22 is a structural diagram of a seventeenth embodiment of the present invention.

FIG. 23 is a structural diagram of an eighteen embodiment of the present invention.

The labels in the figure are: 1-a bit body; 2, a blade; 3-water eye; 4, cutting teeth; 5-module teeth; 51-center tooth; 511 — a diamond layer; 512-a substrate; 52-shaft sleeve; 53-elastic element; 6-3D ratchet; 7, a limiting device; 8, sealing rings; 9-a bearing; 10-bolt; h 1-initial depth of invasion; h 2-depth of intrusion after vibration-absorbing deformation; Δ h — amount of change in depth of invasion; Δ c — the height difference of the two elastic elements; Δ L — amount of elastic deformation of the cushion element; f, cutting load; s1 — stiffness phase of the softer resilient element; s2 — composite stiffness stage for softer, harder elastomeric elements.

Detailed Description

All of the features disclosed in this specification, or all of the steps in any method or process so disclosed, may be combined in any combination, except combinations of features and/or steps that are mutually exclusive.

Any feature disclosed in this specification (including any accompanying claims, abstract) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. That is, unless expressly stated otherwise, each feature is only an example of a generic series of equivalent or similar features.

The first embodiment is as follows:

as shown in fig. 1 to 3, a long-life module cutting tooth and a PDC drill bit using the same include a bit body (1), blades (2), water holes (3) and cutting teeth (4), wherein the blades (2) extend from the bit body (1), and the bit body (1) at the bottom of the blades (2) is provided with the through water holes (3); the cutting teeth (4) are fixedly connected to the blade (2). Wherein, part or all of the cutting teeth (4) are module teeth (5) consisting of a central tooth (51), a shaft sleeve (52) and an elastic element (53); the central tooth (51) consists of a diamond layer (511) and a base body (512). Sawtooth-shaped 3D ratchet teeth (6) are distributed on the end face of the diamond layer (511) along the circumferential direction, a disc spring is arranged between the central tooth (51) and the shaft sleeve (52) and serves as an elastic element (53), and the clamp spring serves as a limiting device (7). The module teeth (5) are fixedly connected on the blades (2) of the PDC drill bit.

In the solution of the present patent, the central tooth (51) has two degrees of freedom, namely: an axial translational degree of freedom along the central tooth axis and a rotational degree of freedom about the central tooth axis. When the PDC drill bit breaks rocks and creeps into, cutting load acts on the 3D ratchet (6), and due to the asymmetric structure of the sawtooth-shaped 3D ratchet (6), the central tooth (51) can rotate regularly in the circumferential direction under the action of torque, cutting edges can be uniformly abraded, and the service life of the drill bit is greatly prolonged. In addition, the 3D ratchet (6) can contact with the rock by a sharp point to break the rock in a ploughing mode, and has the advantages of strong invasion capacity, high rock breaking efficiency, small breaking specific work and the like. When the modular tooth drill meets gravel or a hard interlayer in the drilling process (shown in figure 3), the elastic element (53) can play a role of buffering and absorbing vibration (the penetration depth is reduced from h1 to h 2'), so that overload impact damage of the diamond layer (511) can be effectively prevented, and the occurrence rate of abnormal failure accidents such as tooth breakage, delamination, tooth breakage and the like of the cutting tooth is reduced.

Example two:

as shown in fig. 4, this embodiment is substantially the same as "embodiment one". The difference lies in that: the 3D ratchet teeth (6) are distributed inwards towards the center on the diamond layer (511).

The 3D ratchet (6) in a concave form can reduce the equivalent rake angle when the cutting teeth cut the rock, and reduce the compaction effect in the cutting process. Particularly when drilling in medium-hard or medium-hard soft stratum, the method is favorable for improving the rock breaking efficiency.

Example three:

as shown in fig. 5, this embodiment is substantially the same as "embodiment one". The difference lies in that: the 3D ratchet teeth (6) are convexly distributed on the diamond layer (511) towards the center direction.

The 3D ratchet (6) in the convex form can increase the equivalent rake angle when the cutting teeth cut rocks, and can improve the shock resistance of the diamond layer of the cutting teeth when a stratum above medium hardness is drilled.

Example four:

as shown in fig. 6, this embodiment is substantially the same as "embodiment one". The difference lies in that: the sleeve (52) is of a through hole type structure, the elastic element (53) is arranged at one end close to the diamond layer (511), and the limiting device (7) is arranged at the other end opposite to the diamond layer (511).

The embodiment has the advantages of convenient assembly and disassembly and convenient repair.

Example five:

as shown in fig. 7, this embodiment is substantially the same as "embodiment four". The difference lies in that: a thrust bearing (9) is also arranged on the elastic element (53).

In order to further improve the rotation capacity of the central tooth (51), the thrust bearing (9) is arranged for reducing the friction resistance between the central tooth (51) and the shaft sleeve (52), and improving the effects of uniform abrasion of the cutting edge of the cutting tooth at 360 degrees and enhancing the wear resistance.

Example six:

as shown in fig. 8, this embodiment is substantially the same as "embodiment four". The difference lies in that: the elastic element (53) is arranged at the other end relative to the diamond layer (511)

Example seven:

as shown in fig. 9 and 10, this embodiment is basically the same as "embodiment one". The difference lies in that: the limiting device (7) is a semicircular key.

The semicircle key in this embodiment has better dismouting characteristic as stop device.

Example eight:

as shown in fig. 11, this embodiment is substantially the same as "embodiment seven". The difference lies in that: and a sealing ring (8) is also arranged between the central tooth (521) and the shaft sleeve (52).

The drill bit has a complex underground working environment, various solid-phase particles are suspended in drilling fluid, abrasive particles are easily abraded after entering a rotating contact surface between a base shaft sleeve and a central tooth base body, and the relative movement resistance of the drill bit can be increased in serious cases, so that the drill bit cannot rotate; if drilling fluid solid phase granule causes the grit wearing and tearing in entering into the damping cavity to lead to the elastic buffering ability to lose, influence cutting teeth and drill bit life, consequently set up seal structure and can provide good operational environment for this scheme, improve its reliability.

Example nine:

as shown in fig. 12, this embodiment is substantially the same as "embodiment eight". The difference lies in that: a floating ring (9) is also arranged close to the elastic element (53).

The floating ring is arranged for reducing the friction resistance between the central tooth and the shaft sleeve, so that the central tooth can rotate more flexibly.

Example ten:

as shown in fig. 13 and 14, the present embodiment is basically the same as "embodiment seven". The difference lies in that: the elastic elements are two types, namely an elastic element (531) with smaller rigidity and an elastic element (532) with larger rigidity, and the two types are installed in parallel. The height of the elastic element (531) with smaller rigidity is higher than that of the elastic element (532) with larger rigidity by delta c height difference.

When the central tooth cuts and breaks rocks, the drilling only works on the elastic element (531) with smaller rigidity when encountering softer strata, the elastic element changes within the range of 0 to delta c elastic deformation, and the corresponding rigidity is S1 section; when drilling in a harder stratum, the drilling tool and the drilling tool both participate in work, the expansion and contraction amount of the central teeth is larger than delta c, and the corresponding rigidity is S2. This further widens the application range of the technical solution of the present invention, namely: the same drilling process is suitable for both softer and harder formations.

Example eleven:

as shown in fig. 15, this embodiment is substantially the same as "embodiment six". The difference lies in that: the limiting device (7) is a locking ball, and a sealing ring (8) is arranged on the base (521) and the shaft sleeve (52)

A small hole (11) is made in the sleeve through which the locking ball is mounted in the locked position and is plugged with a plug pin. The locking mode has the advantages of good safety, high reliability, low friction torque and the like.

Example twelve:

as shown in fig. 16 and 17, this embodiment is basically the same as "embodiment eleven". The difference lies in that: the 3D ratchet (6) is in a specific form that a plurality of PDC teeth are fixedly connected to the base (512) in a welding mode.

In the technical scheme, through reasonable design of the side corner and the front rake, torque can be introduced into the central tooth in the cutting process to push the central tooth to rotate.

Example thirteen:

as shown in fig. 18, this embodiment is substantially the same as "embodiment one". The difference lies in that: at least two sets of module teeth are arranged on the same shaft sleeve (52).

Two or more groups of central teeth, elastic elements matched with the central teeth, axial limiting structures, sealing structures and the like are arranged on the same base shaft sleeve, so that a multi-tooth combined cutting tooth is formed, the structural size can be reduced, the tooth distribution space is fully utilized, and the implementation of the patent is facilitated.

Example fourteen:

as shown in fig. 19, this embodiment is substantially the same as "embodiment one". The difference lies in that: the module teeth (5) are fixed on the blade (2) through bolts (10).

The consolidation mode is convenient for disassembly and assembly and replacement of the module teeth, the cost and the manufacturing period are correspondingly reduced, and the manufacturability is good.

Example fifteen:

as shown in fig. 20, the present embodiment is substantially the same as the "fourteenth embodiment". The difference lies in that: the bolt (10) penetrates through the shaft sleeve (52), the elastic element (53), the base (512) and the diamond layer (511), and the module tooth is installed on the blade (2).

The base is fixedly connected to the blade in a welding mode, and other parts of the module teeth are combined together through bolts. This mounting has a higher reliability.

Example sixteen:

as shown in fig. 21, this embodiment is substantially the same as "embodiment one". The difference lies in that: a blind hole is directly formed in the blade (2) and serves as a shaft sleeve of the module tooth, and the elastic element (53), the central tooth (512), the limiting device (7) and the like are installed and fixed in the blind hole.

The technical scheme that this embodiment provided has simplified module tooth component structure, has further promoted the security.

Example seventeen:

as shown in fig. 22, this embodiment is substantially the same as "embodiment one". The difference lies in that: the PDC drill bit is a cone type PDC composite drill bit.

The technical scheme provided by the invention is also suitable for the gear type PDC composite drill bit.

Example eighteen:

as shown in fig. 23, this embodiment is substantially the same as "embodiment one". The difference lies in that: the PDC drill bit is a disc cutter type PDC composite drill bit.

The technical scheme provided by the invention is also suitable for the disc cutter type PDC composite drill bit.

Claims (10)

1. A long-life module cutting tooth and a PDC drill bit adopting the cutting tooth comprise a drill bit body (1), blades (2), water holes (3) and cutting teeth (4), wherein the blades (2) extend from the drill bit body (1), and the drill bit body (1) at the bottom of the blades (2) is provided with the through water holes (3); the cutting teeth (4) are fixedly connected to the blade (2), wherein at least one cutting tooth (4) is a module tooth (5) consisting of a central tooth (51), a shaft sleeve (52) and an elastic element (53); the central tooth (51) is composed of a diamond layer (511) and a base body (512), and is characterized in that: 3D ratchet teeth (6) are distributed on the end face of the diamond layer (511) along the circumferential direction, an elastic element (53) and a limiting device (7) are arranged between the central tooth (51) and the shaft sleeve (52), and the module tooth (5) is fixedly connected to a blade (2) of the PDC drill bit.

2. The long life modular cutter of claim 1 and PDC bit incorporating same, wherein: sawtooth-shaped 3D ratchet teeth (6) are distributed on the end face of the diamond layer (511) along the circumferential direction, the elastic element (53) is a disc spring, and a limiting device (7) arranged between the central tooth (51) and the shaft sleeve (52) is a clamp spring or a semicircular key.

3. The long life modular cutter and PDC bit incorporating the same of claims 1 and 2, wherein: the sleeve (52) is of a through hole type structure, the elastic element (53) is arranged on one side close to the diamond layer (511), and the limiting device (7) is arranged on the other side opposite to the diamond layer (511).

4. The long life modular cutter of claim 1 and PDC bit incorporating same, wherein: the elastic element (53) is a disc spring, or rubber, or a high-elasticity metal body, or a composite material with elasticity, or a combination of at least two of the above.

5. The long life modular cutter and PDC bit incorporating same of claims 1 and 4, wherein: the elastic element (53) is composed of a disc spring (531) and rubber (532), and the two are arranged in parallel or in series.

6. The long life modular cutter and PDC bit incorporating the same of claims 1 and 2, wherein: and a sealing ring (8) is also arranged between the central tooth (51) and the shaft sleeve (52).

7. The long life modular cutter and PDC bit incorporating the same of claims 1 and 2, wherein: a bearing (9) is also arranged between the central tooth (51) and the shaft sleeve (52).

8. The long life modular cutter and PDC bit incorporating the same of claims 1 and 2, wherein: the 3D ratchet teeth (6) are distributed inwards or outwards in the center direction on the diamond layer (511).

9. The long life modular cutter of claim 1 and PDC bit incorporating same, wherein: the module teeth (5) are fixedly connected with the blade (2) through bolts (10).

10. The long life modular cutter of claim 1 and PDC bit incorporating same, wherein: the PDC drill bit is a drill bit provided with diamond cutting teeth, such as a conventional PDC drill bit, a disc cutter type PDC composite drill bit, a cone type PDC composite drill bit and the like.

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