DIAMOND DRILL BIT WITH SELF-ADAPTIVE CUSHIONING MODULE

Abstract

A diamond drill bit has a blade, a cutting tooth, at least one cushioning module rotatably connected to a drill bit body. A cushioning portion of the cushioning module is eccentrically arranged with respect to a rotation axis of the cushioning module. The cushioning module interacts with rock to achieve, in a rotating manner, the contraction and extension trend movement of the cushioning portion on the cushioning module with respect to the cutting teeth. Under the working conditions of guide drilling, composite drilling and other complex movement or under the conditions of drilling in a hard stratum and an uneven stratum, the cushioning portion performs an extension trend movement when the cutting teeth of the blades are subjected to impact loads, so as to achieve the purposes of absorbing impact loads and reducing or avoiding impact damage of the cutting teeth.

Description

TECHNICAL FIELD

The present invention belongs to the technical equipment field of oil and natural gas drilling engineering, mining engineering, construction foundation engineering drilling construction, geological drilling, geothermal drilling, hydrological drilling, tunnel engineering, shield tunneling and trenchless engineering, and in particular relates to a diamond drill bit with a self-adaptive cushioning module.

BACKGROUND

Rock breaking is the fundamental problem of drilling. Mechanical rock breaking is still the main operation method in oil and gas drilling at this stage. The drill bit is a rock breaking tool used to break the rock and form a wellbore. The drill bit plays an irreplaceable role in drilling engineering as the absolute main force. PDC drill bits are the most commonly used. The roller cone bit relies on the extrusion of the teeth on the bottom hole rock to generate lateral pressure, and the lateral pressure forms shear force. After the rock reaches the shear strength, it breaks and fails. In this process, the transmission and transformation of energy reduces its utilization rate. PDC drill bits are gradually replacing roller cone bits in soft to medium hard formations by virtue of their efficient shearing method. In particular, the rapid progress of cutting tooth material technology, basic theory of drill bits, and bit design technology has broadened the formation adaptability of PDC drill bits, and the proportion of PDC drill bits in the total footage of oil and gas drilling has increased from 5% in the 1880s. to 90%. Fixed cutter bits represented by PDC drill bits usually have several blades, and the blades are provided with a plurality of cutters along the radial direction of the bit (for PDC drill bits, the cutters are mainly polycrystalline diamond composite sheets, referred to as composite sheets for short or PDC teeth). According to data, the deep complex formation, which only accounts for 20% of the total footage, spends 80% of the total cost of the entire drilling cycle. Difficult-to-drill strata mainly refer to the poor drillability of the stratum, which is manifested by high rock hardness, high inhomogeneity, strong abrasiveness, and high temperature. These rock properties may have various complex combinations and changes, and are generally unpredictable, especially in the deep formations of deep and ultra-deep wells. The drill bit has a short drilling life in complex and difficult-to-drill formations, consumes more drill bits, and causes frequent trips and trips, which has become one of the technical bottlenecks restricting the cost reduction and efficiency increase of drilling engineering.

During the drilling process, the cutting teeth of the PDC drill bit overcome the ground stress and bit into the formation under the action of the WOB, and shear and break the formation material under the drive of torque. Compared with the rock breaking method of impact rolling of the roller cone bit, the required driving torque is larger. When drilling into deep and difficult-to-drill strata, especially when encountering soft and hard staggered, gravel-bearing strata, the biting depth of the drill bit into the stratum frequently changes, and the drill bit vibrates violently in the circumferential, lateral and axial directions. At this time, the cutting teeth of the drill bit are subjected to large circumferential and axial impact loads, resulting in chipping of the drill bit, damage, breakage of the drill tool, and damage to other downhole tools and measuring instruments, which seriously affects the drilling efficiency. In particular, the cutters in the outer third of the drill are more susceptible to damage due to the high linear velocity. When the cutting teeth of the PDC drill bit are worn, in order to maintain a certain ROP, the WOB is often increased, and the torque is particularly sensitive to the WOB. With the increase of the WOB, the torque increases, which makes the working condition of the drill bit worse, and the drill is thus more prone to failure. How to increase the working life of PDC drill bit in deep and difficult-to-drill formations and reduce the sensitivity of bit torque to WOB is an important technical problem to prolong the service life of downhole drilling tools and drill bits and improve drilling efficiency.

To this end, researchers in the field have begun to try to set a cushion structure on the drill bit, such as a diamond drill bit suitable for hard formation drilling (application number: 201810138571.X), which proposes to extend a buffer base in front of the blade, and provide a buffer element on the buffer base, which may effectively reduce the circumferential span and reduce the circumferential impact vibration when the drilling is complex and it is difficult to drill into the formations, thus reducing the axial impact and playing the role of protecting the PDC teeth. However, the buffer element in this patent is a fixed buffer element, and the relative height between the buffer element and the diamond teeth is a fixed value. The fixed buffer element has a narrow stratum adaptation range. For strata with complex and changeable lithology, especially for the drilling from hard strata into soft formations, the fixed buffer element will reduce the biting capacity of the diamond teeth and reduce the rate of penetration of the drill bit.

SUMMARY

The purpose of the present invention is to: provide a diamond drill bit with a self-adaptive cushioning module in view of the above-mentioned problems, so as to solve the problem that the drill bit is difficult to drill in complex and difficult to drill strata, complex vibration, especially directional drilling, compound drilling and other working conditions, and solve the problem of rapid failure of cutting teeth due to impact, thereby protecting the cutting teeth, and thus prolonging the service life of the drill bit. In particular, the present invention solves the problems of insufficient impact resistance of the existing PDC drill bit, large torque fluctuation and poor directional drilling performance in directional drilling.

The purpose of the present invention is achieved through the following technical solutions; a diamond drill bit with a self-adaptive cushioning module, comprising a drill bit body and a blade extending from the drill bit body, wherein the blade is provided with cutting teeth, at least one cushioning module is provided on the drill bit, the cushioning module is rotatably connected to the drill bit body, and a cushioning portion of the cushioning module is eccentrically arranged with respect to a rotation axis of the cushioning module.

When the cushioning portion of the cushioning module in the initial position bears the impact force from formation rock, the cushioning portion absorbs impact load, reduces the impact force of the blade cutting teeth, and cushions the cutting teeth.

Under the action of the force in contact with the bottom hole rock, the cushioning portion of the cushioning module rotates relative to the cutting teeth to perform a shrinking trend movement, so as to reduce or avoid the impact of the cushioning module on the intrusion depth of the cutting teeth.

When the cushioning portion of the cushioning module is out of contact with the bottom hole rock or when the contact resistance torque is less than a reset torque, under the action of a reset mechanism, the cushioning portion rotates to the initial position of the cushioning portion in a rotational manner, so as to realize a protruding tendency movement relative to the cutting teeth. The position of the cushioning portion relative to the cutting teeth is raised, which plays a cushioning role for the subsequent impact of the cutting teeth. There are two types of reset mechanisms: one is a spring as an energy storage element, and the cushioning portion performs a reset motion under the drive of spring force or torque. The other is a hydraulic reset structure or a hydraulic reset device. The hydraulic reset device has two structural types, one is a linear reciprocating motion reset structure, and the other is a rotary reset structure. The hydraulic reset structure usually also requires a spring to provide reset driving force or torque. The hydraulic circuit of the hydraulic reset structure is provided with a small-diameter check valve and a large-diameter check valve. During the cushioning process of the cushioning portion, the small-diameter check valve is opened, and the large-diameter check valve is closed. Therefore, the liquid stroke resistance is large, which may achieve a better cushioning effect. During the reset stroke, the large-diameter check valve is opened, the liquid resistance is small, and rapid reset may be achieved.

In the solution above, the relative height between the cushioning module and the drill bit cutting teeth is adjusted according to the formation conditions, so as to reduce the premature failure of the cutting teeth caused by impact or vibration, and prolong the working life of the drill bit when drilling in hard formations. Moreover, during normal drilling, the cushioning module will not affect the penetration ability and cutting efficiency of the cutting teeth of the drill bit like the fixed cushion section.

Preferably, the cushioning module is arranged on the blade and is rotatably connected to the blade.

Preferably, when the cushioning module is in the initial position, the height difference H between the highest point of the cushioning portion of the cushioning module and the highest point of the cutting tooth edge is: −D≤H≤D, where D is the diameter of the cutting tooth.

Preferably, the cushioning module comprises a rotating body and cushion teeth, the rotating body is rotatably installed in a base hole of the blade, and the cushion teeth are eccentrically arranged relative to the rotation axis of the rotating body to form a cushioning portion. The rotating body is connected to a reset mechanism arranged on the drill bit, so that the cushioning module may be automatically reset after being rotated by an external force and when the external force disappears.

Preferably, the cushion teeth are inlaid and fixed on the rotating body, or the cushion teeth are rotatably connected to the rotating body, or the cushion teeth and the rotating body are integrally formed.

In the solution above, the cushion teeth may be fixed on the rotating body by means of interference fit, welding, screw connection, etc., and different types of cushion teeth may be easily replaced according to the formation conditions and the needs of the drill bit structure. The cushion teeth may also be of the design of integrating with the rotating body, which is easy to process. The cushion teeth are connected by rotation on the rotating body, which may reduce the friction between the cushion teeth and the rock, reduce the wear rate of the cushion teeth, and prolong the service life of the cushioning module.

Preferably, the cushion teeth are spherical teeth, wedge teeth, conical teeth or PDC teeth.

Preferably, a wear-resistant layer is provided on the surface of the cushion teeth.

In the solution above, the wear-resistant layer may increase the wear resistance of the cushion teeth and improve the service life of the cushion teeth.

Preferably, a casing is provided between the rotating body and the base hole, the casing is fixed on the blade, the rotating body is installed in the casing, and the rotating body and the casing are rotatably connected.

Preferably, the cushioning module is installed on a drill bit in which the PDC cutting structure is combined with other cutting structures comprising a movable cutting structure.

In the solution above, other movable rock-breaking structures may be roller rock breaking structures, disc cutter rock breaking structures, impact rock breaking structures, or a combination of at least two rock breaking structures therebetween. According to different formation conditions and drilling process parameters, different cutting structure combinations are selected to enhance the adaptability of the drill bit in specific formations.

Preferably, the size range of the front inclination angle of the cushioning module is 0°≤α≤60°, and the value range of the deflection angle is −60°≤β≤60°.

In the solution above, since the cushioning module has a certain inclination angle and the cushion teeth are eccentrically arranged with respect to the axis of the rotating body, the cushioning module as a whole presents a state in which one side is high and the other side is low. When the drill bit is initially drilling, due to the friction between the rock and the cushion teeth, the cushion teeth and the rotating body rotate around the axis of the rotating body from the free state, that is, the cushion teeth move from the free state on the lowest side to the highest side, and the reset mechanism accumulates energy at the same time. When the drill bit encounters an inhomogeneous stratum or a brittle stratum, the drill bit jumps up, and the friction between the cushioning portion of the cushioning module and the stratum is reduced, that is, the rotational torque provided by the friction force is lower than the reset torque provided by the reset mechanism. The reset mechanism releases the accumulated elastic energy, so that the rotating body and the cushion teeth are rotated to a free state, and the relative height between the cushion teeth and the fixed cutting teeth of the drill bit is reduced. When the drill bit falls to the bottom of the hole, the cushion teeth may absorb the impact force generated when the drill bit returns to the wheel, so as to achieve the effect of cushioning and avoid the situation that the cutting depth of the drill bit cutting teeth is too large instantaneously. After that, when the drill bit is drilling normally, the reset mechanism drives the rotating body to rotate under the friction of the rock, and the cushion teeth have a process of retracting into the knife wing relative to the drill bit blade, and the reset mechanism re-accumulates energy, and so on, the self-adaptive adjustment of the cutting depth of the drill cutter is realized.

Preferably, the reset mechanism is a torsion spring.

In the solution above, the torsion spring is used as the reset mechanism after the rotating body is rotated under force. During the rotation of the rotating body, the torsion spring is used to store energy, and the characteristic that the resistance of the torsion spring increases with the increase of deformation is fully utilized to improve the cushion effect. And after the force disappears, it may be quickly reset to prepare for the next shock relief.

Preferably, the rotating body of the cushioning module performs a telescopic movement along the axial direction while rotating.

In the solution above, the axial expansion and contraction of the cushioning module is used to realize the automatic adjustment of the relative height between the cushion teeth and the cutting teeth according to the nature of the formation and the working state of the cutting teeth, so as to absorb the drilling pressure when the drill bit hits the bottom hole and avoid the cutting teeth from being damaged due to impact, thereby prolonging the working life of the drill bit.

Preferably, the rotating body is provided with a helical groove, and a protrusion corresponding to the helical groove is formed on the axial movement path of the rotating body.

In the solution above, through the arrangement of the helical groove on the rotating body, the degree of strict requirements on the installation angle of the cushioning module on the blade is reduced, which facilitates the processing of the drill bit. During normal drilling, when the cushion teeth rotate under the friction of the bottom hole rock, it drives the rotation of the rotating body, and the rotating body may climb along the helical groove while rotating, thereby reducing the protrusion of the cushion teeth. At the same time, due to the provision of the reset mechanism, the rotation of the rotating body may make the reset mechanism store energy. When the drill bit bounces when drilling into an inhomogeneous or brittle formation, the friction between the cushion teeth and the formation rock is reduced, and the energy accumulated by the reset mechanism makes the rotating body rotate in the opposite direction and move along the orbit of the helical groove, thereby increasing the protrusion. When the drill bit falls to the bottom of the hole, the cushion teeth may absorb the impact force generated when the drill bit returns to the wheel, so as to achieve the effect of cushioning and avoid the situation that the cutting depth of the drill bit cutting teeth is too large instantaneously. After that, when the drill bit is drilling normally, the cushion teeth drive the rotating body to rotate under the friction of the rock, the relative height between the cushion teeth and the cutting teeth is reduced, and the reset mechanism re-accumulates energy, and so on, the self-adaptive adjustment of the cutting depth of the drill cutter is realized.

Preferably, the reset mechanism is a torsion spring, a compression spring or a hydraulic reset structure. In the solution above, the quick reset of the cushioning module may be realized by using the torsion spring, the compression spring or the hydraulic reset structure.

Preferably, motion and force/torque may be transmitted between the reset mechanism and the cushioning portion through a gear mechanism (comprising a rack-and-pinion mechanism, a bevel gear mechanism), a coupling, a chain drive and other transmission mechanisms.

Compared with the prior art, the beneficial effects of the present invention are:

• • 1. The cushioning module on the drill bit may automatically adjust the height between the cutter and the cutting teeth. During normal drilling, it does not affect the intrusion ability of the cutting teeth and maintains a fast ROP of the drill bit. When the drill bit is impacted, the cushioning portion of the cushioning module quickly returns to the original position to effectively absorb the impact load of the drill bit, so as to avoid the cutting teeth failure caused by the large impact of the drill bit, and prolong the life of the drill bit.
  • 2. In the process of directional well drilling, the drill bit works in a similar way to milling, and each blade of the drill bit acts on the formation rock in turn. In such case, the height between the cushioning portion and the cutting teeth is adjusted by means of axial expansion. Since on the side where the drill bit interacts with the rock, the cushioning portion of this structure cannot play an effective contact role with the rock, so it is difficult to play a cushion role. However, the cushioning module mentioned in this patent may adjust the relative height with the cutting teeth in a rotational manner through the friction with the rock, and may play an effective cushion role in directional well drilling.
  • 3. In addition to revolving around the axis of the cushioning module, the cushion tooth may also rotate around its own axis, which may reduce the friction between the cushion tooth and the formation and prolong the service life of the cushioning module.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described by way of specific embodiments with reference to the accompanying drawings, wherein

FIG. 1 is a schematic structural diagram of a self-adaptive cushioning module provided by the present invention.

FIG. 2 is a top view of FIG. 1.

FIG. 3 is a schematic diagram of the definition of the lateral rotation angle and the front inclination angle of the cushioning module.

FIG. 4 is a schematic diagram of the working position of the cushioning module in Embodiment 1.

FIG. 5 is another schematic diagram of the working position of the cushioning module in Embodiment 1.

FIG. 6 is a schematic diagram of the change of a moment arm of the cushion tooth.

FIG. 7 is a schematic diagram of the working attitude of the drill bit in directional drilling.

FIG. 8 is a schematic diagram of the span of the drill bit blade in directional drilling.

FIG. 9 is a schematic diagram of the structure of installing PDC teeth on the cushioning module.

FIG. 10 is a schematic diagram of a flat insert structure of the cushion teeth as spherical PDC teeth.

FIG. 11 is a schematic diagram of the structure of the cushion teeth as insert teeth.

FIG. 12 is a schematic diagram showing that a secondary cushioning portion is a convex ring.

FIG. 13 is a schematic diagram of the installation position of the cushioning module on the blade relative to the cutting teeth.

FIG. 14 is a schematic view of the structure of the cushioning module installed on an extension support of the blade.

FIG. 15 is a schematic structural diagram of the blade extension support being a cantilever beam.

FIG. 16 is a schematic diagram of a connecting body in which the blade extension support is two adjacent blade blades.

FIG. 17 is a schematic diagram of a disc cutter rock breaking structure as the movable structure.

FIG. 18 is a schematic diagram of the movable structure being an impact rock breaking structure.

FIG. 19 is a schematic diagram of the movable structure being the roller rock breaking structure.

FIG. 20 is a schematic diagram of the structure of the cushion teeth that may freely rotate relative to the rotating body.

FIG. 21 is a schematic structural diagram of the cushioning module provided in Embodiment 2.

FIG. 22 is a schematic structural diagram of the cushioning module provided in Embodiment 3.

FIG. 23 is a schematic structural diagram of the cushioning module provided in Embodiment 4.

FIG. 24 is a schematic structural diagram of the cushioning module provided in Embodiment 5.

FIG. 25 is a schematic structural diagram of the cushioning module with hydraulic reset function provided in Embodiment 6.

FIG. 26 is a schematic structural diagram of the cushioning module provided in Embodiment 7.

FIG. 27 is a schematic structural diagram of the cushioning module provided in Embodiment 8.

FIG. 28 is a schematic structural diagram of a cushioning module with gear-rack meshing.

Among them, 91 is the center line of the drill bit, 911 is the center line of the wellbore, 1 is the blade, 10 is the inner flow channel of the blade, 11 is the base hole, 101 is the first blade, 102 is the second blade, and 103 is the third blade, 104 is the fourth blade, 105 is the fifth blade, 106 is the fixed cushioning module, 110 is the blade extension support, 2 is the cutting tooth, 3 is the cushioning module, 301 is the casing, 302 is the rotating body, 3021 is the outer cover, 3022 is the rotating support seat, 3023 is the screw, 3024 is the wear-resistant support, 303 is the reset mechanism, 304 is the cushion tooth, 3041 is the secondary cushioning portion, 305 is the ball, 306 is the direction reference line, 307 is the helical groove, 308 is the protrusion, 309 is the cavity, 310 is the sealing ring, 311 is the rotation axis of the cushioning module, 5 is the hydraulic device, 501 is the first chamber, 502 is the second chamber, 503 is the intermediate valve seat, 504 is the first check valve (small-diameter check valve), 505 is the second check valve (large-diameter check valve), 506 is the energy storage element, 507 is the reset piston, 508 is the gear, 509 is the rack, 6 is the disc cutter rock breaking structure, 7 is the impact rock breaking structure, 8 is the roller rock breaking structure, 9 is the curved screw, 910 is the drill bit, and 912 is the drill bit body.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The technical solutions of the embodiments of the present invention will be described clearly and completely as follows in combination with the figures of these embodiments for a clear understanding of the purposes, technical solutions and advantages of the present invention. Apparently, the embodiments described are only some, not all of the embodiments of the present invention. Generally, the components in the embodiments of the present invention described and shown in the figures herein may be arranged and designed in various configurations.

Therefore, the detailed descriptions of the embodiments of the present invention provided in the figures are not intended to limit the scope of the present invention, and the embodiments are only certain embodiments of the present invention. Based on the embodiments of the present invention, other embodiments acquired by those of ordinary skill in the art without creative work also belong to the protection scope of the present invention.

It should be noted that the features in the embodiments and the embodiments of the present invention may be combined with each other in a non-conflicting situation.

It should be noted that similar marks and letters generally indicate similar items. Therefore, any item already defined in one figure is not necessarily further defined and explained in the subsequent figures. For description of the embodiments in the present application, it should be noted that orientation or position relations indicated are based on the orientation or position relations shown in the figures or the commonly arranged orientation or position relations as used in the applied product, or the orientation or position relations commonly understood by those skilled in the art or the orientation or position relations commonly placed when the applied product is used, and they are used to describe the present application and simplify description herein instead of indicating or implying that the equipment or component indicated must have specific orientation and be constructed and operated in specific orientation. Therefore, the embodiments described herein shall not be construed as limitation hereto. In addition, the terms “first” and “second” are only used to distinguish descriptions instead of being construed as indication or implication of relative importance.

In the description of the embodiments of present invention, it should be also noted that unless otherwise explicitly specified and defined, the terms “arrangement” and “connection” are to be understood in a broad sense, for example, a fixed connection, a removable connection, or an integral connection, or understood as directly connected or indirectly connected through an intermediate. Those of ordinary skill in the art may understand the specific meanings of these terms in the present invention according to actual conditions. The technical solutions contained in the embodiments of the present invention are described in detail clearly and completely hereinafter with references to the accompanying drawings for the embodiments of the present invention. Apparently, the described embodiments are only a portion of embodiments of the present invention, but not all the embodiments of the present invention. Generally, the components in the embodiments of the present invention described and shown in the figures herein may be arranged and designed in various configurations.

EMBODIMENT 1

The present invention provides a diamond drill bit with a self-adaptive cushioning module, comprising a drill body 912 and a blade 1 extending from the drill body 912, wherein the blade 1 is provided with cutting teeth 2, and at least one cushioning module 3 is provided on the drill bit 910; the cushioning module 3 is rotatably connected to the drill bit body 912, and a cushioning portion of the cushioning module 3 is eccentrically arranged relative to a rotation axis of the cushioning module 3.

When the cushioning portion of the cushioning module 3 in the initial position bears the impact force from the formation rock, the cushioning portion absorbs the impact load, reduces the impact force of the blade cutting teeth, and cushions the cutting teeth 2.

Under the action of the force in contact with the bottom hole rock, the cushioning portion of the cushioning module 3 rotates relative to the cutting teeth to perform a shrinking trend movement, so as to reduce or avoid the impact of the cushioning module 3 on the intrusion depth of the cutting teeth 2. When the cushioning portion of the cushioning module 3 is out of contact with the bottom hole rock or when the contact resistance torque is less than a reset torque, under the action of a reset mechanism 303, the cushioning portion rotates to the initial position of the cushioning portion in a rotational manner, so as to realize a protruding tendency movement relative to the cutting teeth 2. The position of the cushioning portion relative to the cutting teeth is raised, which plays a cushioning role for the subsequent impact of the cutting teeth 2.

As shown in FIG. 1, it is a schematic structural diagram of a drill bit provided by an embodiment of the present invention. Specifically, as shown in FIGS. 2 to 5, the cushioning module 3 comprises a rotating body 302 and a cushion tooth 304; a wear-resistant layer is provided on the surface of the cushion tooth 304, and the rotating body 302 is rotatably mounted on a base hole 11 of the blade 1; a casing 301 is arranged between the rotating body 302 and the base hole 11, and the casing 301 is fixed on the blade 1; the rotating body 302 is installed in the casing 301, and the rotating body 302 forms a rotational connection with the casing 301; the reset mechanism 303 is arranged between the casing 301 and the rotating body 302, and the rotating body 302 is connected to the reset mechanism 303 arranged in the casing 301. After the cushioning module 3 is rotated by external force and automatically reset when the external force disappears, the cushion teeth 304 are eccentrically arranged relative to the rotation axis of the rotating body 302 to form a cushioning portion, that is, the highest point of the cushion teeth is not on the axis of the rotating body.

As shown in FIG. 4, the reset mechanism 303 between the casing 301 and the rotating body 302 is a torsion spring, and the casing 301 and the rotating body 302 are fixed in the axial direction through a ball 305.

When the drill bit as a whole is not in contact with the rock, the position of the cushioning module is called the initial position. When the cushioning module 3 is in the initial position, the height difference H between the highest point of the cushioning portion of the cushioning module 3 and the highest point of the cutting tooth 2 edge is: −D≤H≤D, where D is the diameter of the cutting tooth 2.

Among them, several concepts are defined by the posture of the cushioning module at the initial position, specifically:

• • in the initial position, the relative height H between the cushion tooth 304 and the cutting tooth 2 may be in three ways, namely: the cushion tooth 304 is higher than the cutting tooth 2, the cushion tooth 304 is flush with the cutting tooth 2, and the cushion tooth 304 is lower than the cutting tooth 2. As shown in FIG. 4, the cushion teeth 304 are arranged higher than the cutting teeth 2.

As shown in FIGS. 2, 0 is the center point of the drill bit, 01 is the positioning center point of the cushioning module 3, and 02 is the center point of the cushioning portion. Assuming that there is a cutting plane on the drill bit that passes through the axis of the drill bit and a point on the drill bit, this plane is called the axis plane or axial plane passing through that point. Then, as shown in FIG. 3, in the axial plane passing through the center point O1 of the cushioning module 3, the normal line of the outline of the drill bit crown passing through the center point O1 of the cushioning module is called the direction reference line 306 of the cushioning module.

As shown in FIG. 3, the included angle between the direction reference line 306 of the cushioning module 3 and the center line 91 of the drill bit is called the normal angle γ of the cushioning module 3, and the symbol of the normal angle γ is positive in the direction shown in the figure, and negative at the inner cone of the drill bit. The angle between the rotation axis 311 of the cushioning module 3 and the direction reference line 306 is called the deflection angle β of the cushioning module, and the value range of β is −60°≤β≤60°.

Referring to FIG. 3, viewed from the direction A, the included angle between the rotation axis 311 of the cushioning module 3 and the direction reference line 306 is called the front inclination angle of the cushioning module, and the symbol of the front inclination angle is positive in the direction shown in the figure. The range of the inclination angle of the cushioning module is 0°<α≤60 °.

Referring to FIG. 2, a straight line 01M is formed by connecting the center point 0 of the drill bit and the center point 01 of the cushioning module 3, and a vertical line 01N of 01M is made through the point 01, and the direction of 01N is the same as the rotation direction of the drill bit. Connecting the center point 01 of the cushioning module 3 and the center point 02 of the cushion tooth 304, the angle between the lines 0102 and 01N is defined as the working angle K of the cushioning module 3. The value range of K is 0°<K≤180°.

It should be noted that, according to the structural design requirements of the cushioning module 3, the cushioning module 3 may be rotated clockwise around the 01 point in the direction shown in the figure, or may be rotated counterclockwise around the 01 point in the direction shown in the figure, whether it is clockwise or counterclockwise rotation, the positive value of K is consistent with the rotation direction of the cushioning module 3.

Referring to FIGS. 4 and 5, when the drill bit is in contact with the bottom hole rock, the cutting teeth 2 scrape the rock, and the eccentric cushion teeth 304 installed on the cushioning module 3 rub against the rock. Since the cushion teeth 304 are installed on the rotatable rotating body 302, under the action of the friction force, the cushion teeth 304 rotate, which drives the rotating body 302 to rotate. The cushioning module 3 has a front inclination angle o when installed. Therefore, when the rotating body 302 rotates, the height between the cushion teeth 304 and the cutting teeth 2 changes, and at the same time, the rotation of the rotating body 302 drives the torsion spring to rotate and causes the torsion spring to accumulate elastic energy. During normal drilling, the cushion teeth 304 rotate to position K under the friction of the formation rock, such as the position of the cushioning module 3 on the blade 1 in FIG. 1. At this time, the cutting teeth 2 bear most of the drilling pressure, while the cushion teeth 304 hardly bear the drilling pressure. The cutting teeth 2 have a relatively deep biting depth and have relatively high rock-cutting ability, and the drill bit has a faster ROP. When the drill bit encounters a heterogeneous stratum or a relatively brittle stratum, the drill bit produces shock vibration in the axial direction and jumps up and down. When the drill bit jumps up the wellbore, the cushion teeth 304 tend to be separated from the bottom hole, the friction between the cushion teeth 304 and the rock is reduced, the elastic energy accumulated by the torsion spring is released, and the rotating body 302 is rotated from the position K to the free state position, that is, the cushion teeth 304 tend to protrude relative to the cutting teeth 2. The impact energy or impact load generated when the drill bit falls back may be absorbed by the extended cushion teeth 304, thereby achieving the purpose of reducing the impact load of the cutting teeth 2, protecting the cutting teeth and prolonging the life of the cutting teeth.

On the other hand, as shown in FIG. 6, the initial position of the cushion teeth 304 is L. At this time, the moment arm L between the cushion teeth 304 and the center of the cushioning module is L, and the moment arm L increases gradually with the rotation of the cushion teeth 304. As the moment arm L increases gradually, the friction force between the cushion teeth 304 and the rock on the center of the cushioning module tends to increase from small to large, so that the rotation speed of the cushion teeth 304 correspondingly changes from slow to fast. When the cushion tooth 304 returns to its original position to play a cushioning role, due to the slow initial rotation speed of the cushion tooth 304, the cushioning effect will not disappear immediately, and the cushioning effect will last for a certain period of time. After that, the rotation speed of the cushion tooth 304 increases before entering stable drilling, which thus does not affect the normal intrusion scraping of the cutting teeth 2.

In particular, during the directional drilling process, the movement posture of the drill bit is shown in FIG. 7. Since the upper part of the drill bit 910 is provided with a curved screw 9, the center line 91 of the drill bit and the center line 911 of the wellbore do not overlap, and there is an included angle ϵ between the two. That is, in addition to the autorotation seed w2 of the drill bit 91 around the center line 91 of the drill bit, the same has a revolution speed ω1 around the center line 911 of the wellbore. At this time, the diameter of the wellbore is larger than the diameter of the drill bit. Due to the expansion of the diameter of the wellbore, during directional drilling, only one side of the drill bit 91 is in contact with the wellbore wall, and there is a situation where the drill bit blade 1 cuts the wellbore wall in turn, as shown in FIG. 8. When switching from one blade contacting the well wall to another blade contacting the well wall, since there is a certain span S between adjacent blades, the drill bit 91 will be subjected to the impact load during the switching of the blade 1. Shock loads may easily lead to rapid failure of the external cutters of the drill. However, in order to increase the build-up effect, the lateral cutting capability of the drill cannot be reduced. Therefore, adding the cushioning module in the present application to the drill bit may reduce the impact during the switching of the blade, without affecting the side cutting ability of the cutting teeth after the impact.

Therefore, the working process of the cushioning module may be divided into three stages:

• • The first is the cushion stage, that is, the initial stage when the blade is impacted. At this time, the cushioning portion is at the initial position, and the initial stage of starting to rotate to a low position (the height of the cushioning portion drops less), in this stage, the contact area between the cushioning portion and the bottom hole rock is large, and it may play a better cushion effect.
  • The second is the stage of sharp reduction of the cushioning effect (or effect of limiting biting depth). In this stage, the cushioning portion is in the middle and late stages of rotation to the lowest position, and the effect of limiting biting depth is significantly reduced until it reaches the lowest position. The third is the stabilization stage. At this time, the cushioning portion is at the lowest position, the effect of limiting biting depth is the weakest, and the corresponding blade is in the stable cutting stage.

The third is the reset phase. The cutting depth of the blade cutting teeth gradually decreases, and the cushioning portion gradually moves in the direction of being out of contact with the bottom hole. At this time, the cushioning portion is quickly reset under the action of the torsion spring.

Further, the cutting teeth 2 may be PDC teeth (polycrystalline diamond compact discs), TSP teeth (thermally stable diamond polycrystalline wafers), ridge teeth, impregnated horizontal teeth with micro-cutting function, and other non-planar diamond cutting teeth. The materials comprise synthetic diamond, natural diamond, impregnated diamond, cemented carbide, cubic boron nitride and ceramics. The cushion teeth 304 on the rotating body 302 are spherical teeth, conical teeth, wedge teeth, PDC teeth and the like. As shown in FIG. 9, it is a schematic structural diagram in which the cushion teeth 304 are conventional PDC teeth. The size of the PDC teeth may be large-sized PDC teeth, such as teeth with a diameter greater than 23 mm. When using conventional PDC teeth as cushion teeth, there are two installation methods for the front inclination angle Q of the cutting teeth: the first is that Q is 0°, the PDC teeth with this rake angle method, the entire side of the tooth column may be in contact with the rock., the contact area is large, and it may withstand greater impact loads. The second is that Q takes a larger rake angle than the cutting teeth 2 on the blade 1. If it is greater than 30°, the larger the front inclination angle, the larger the contact area between the diamond tooth surface and the rock. First, the impact contact area may be increased. Second, It uses the characteristics of strong wear resistance of the diamond layer to prolong the life of the cushion teeth.

The cushion teeth 304 may also be installed in the form of spherical PDC teeth flat inserts, as shown in FIG. 10, which makes full use of the wear resistance of diamond and the blunt characteristics of spherical teeth, and has a strong ability to absorb shock loads and further improves wear resistance. According to the demand for the cushioning effect, the cushion teeth 304 may also be flat-inserted with tapered-ball PDC teeth or pointed-conical PDC teeth.

The cushion teeth 304 may be fixed on the rotating body by means of interference fit, welding, screw connection, etc. As shown in FIG. 11, it is a schematic diagram indicating that the cushion teeth 304 are fixed on the rotating body 302b means of interference fit.

As shown in FIGS. 11 and 12, in addition to the cushion teeth 304, the rotating body 302 also has a secondary cushioning portion 3041, and the secondary cushioning portion 3041 is a spherical tooth, a conical tooth, a wedge tooth, a PDC tooth, etc., the secondary cushioning portion 3041 in FIG. 11 is a schematic diagram of spherical teeth. The secondary cushioning portion 3041 may be fixed on the rotating body by means of interference fit, welding, screw connection and the like. The secondary cushioning portion 3041 may also be other irregular annular bosses, as shown in FIG. 12. Here, the highest point of the secondary cushioning portion 3041 is lower than the highest point of the cushion teeth 304. When the biting depth of the cutting teeth 2 is too large, the cushioning effect of the cushioning teeth 304 is weak, and the addition of the secondary cushioning portion 3041 in this solution may assist in enhancing the cushioning effect of the cushioning module.

For the installation position of the cushioning module on the drill bit, the cushioning module may be installed on the blade where the cutting teeth are located, or may be installed on the independent blade of the drill bit. Taking the five-blade drill in FIG. 13 as an example, the second blade 102 in FIG. 13 is the cushioning module 3 installed on the independent blade of the drill.

For the case where the cushioning module is installed on the blade where the cutting teeth are located, there are also several installation methods. Taking the five-blade drill in FIG. 13 as an example: {circle around (1)} the cushioning module is installed behind the cutting teeth on the blade, for example, the cushioning module 3 installed on the fourth blade 104 in FIG. 13; {circle around (2)} the cushioning module is installed in front of the cutting teeth on the blade, for example, the cushioning module 3 installed on the third blade 103 as shown in FIG. 13; {circle around (3)} the cushioning module and the cutting teeth are installed side by side, for example, the cushioning module 3 installed on the first blade 101 as shown in FIG. 13, For the installation methods above, there may be one installation method or a combination of several installation methods. In addition, the installation method above may also be installed in combination with a fixed cushioning module. As shown in FIG. 13, the fixed cushioning module 106 installed on the fifth blade 105 may be a conical tooth, spherical tooth or other blunt tooth.

Wherein, the cushioning module 3 may also be installed on the blade extension support 110, as shown in FIG. 14. In this solution, the blade extension support 110 may extend toward the front end of the blade blade, or may extend toward the rear end of the blade. FIG. 14 shows a schematic diagram of the blade extension support 110 extending toward the front end of the blade 1. The blade extension support 110 may be connected to the drill body, as shown in FIG. 15, or not connected to the drill body, that is, a cantilever beam is formed between the blade extension support 110 and the blade 1, as shown in FIG. 16. The blade extension support 110 may be a connecting body between two adjacent blades, for example, the blade extension support 110 between the first blade 101 and the second blade 102 as shown in FIG. 16.

The cushioning module may also be installed on the drill bit in which the PDC cutting structure is combined with other cutting structures comprising movable cutting structures. The movable cutting structure may be the disc cutter rock breaking structure 6 shown in FIG. 17, or the impact rock breaking structure 7 shown in FIG. 18, or the roller rock breaking structure 8 shown in FIG. 19, or at least two active rock breaking structures.

In the present embodiment, the cushion teeth 304 are embedded and fixed on the rotating body 302. In addition, the cushion teeth 304 of the cushioning module 3 may freely rotate relative to the rotating body 302. Here is a structure in which the cushion teeth 304 may rotate freely, as shown in FIG. 20. Specifically, the rotating body 302 is composed of an outer cover 3021, a rotating support seat 3022, a screw 3023 and a wear-resistant support 3024. Compared with the cushion teeth 304 fixed on the rotating body 302, the freely rotatable cushion teeth 304 may reduce the rapid wear failure caused by friction between the cushion teeth 304 and the rock, and prolong the working life of the cushion teeth.

EMBODIMENT 2

As shown in FIG. 21, the difference from Embodiment 1 is that the rotating body 302 of the cushioning module 3 performs telescopic movement along the axial direction while rotating.

In the present embodiment, the rotating body 302 is provided with a helical groove 307, and a protrusion 308 corresponding to the helical groove 307 is provided on the path of the axial movement of the rotating body 302.

Specifically, the inner wall of the casing 301 is provided with protrusions 308 corresponding to the helical grooves 307 on the rotating body 302, a reset mechanism 303 is installed between the casing 301 and the rotating body 302, and the cushioning module 3 passes through the casing 301 and the blade 1 to form a fixed connection. In the free state, the uppermost end of the helical groove 307 is in contact with the protrusion 308, that is, the uppermost end of the helical groove 307 serves to limit the rotational position of the rotating body 302. Wherein, the reset mechanism 303 may be an axial reset spring. When the eccentric cushion tooth 304 interacts with the bottom hole rock, the eccentric cushion tooth 304 rotates with the rotating body 302. Due to the existence of the helical groove 307 and the protrusion 308, while the rotating body 302 rotates, an axial movement along the axis direction of the cushioning module may also be generated, and the rotating body 302 is retracted toward the interior of the casing 301. At the same time, the rotating body 302 presses the axial return spring provided between the rotating body 302 and the casing 301, and the axial return spring accumulates energy. When the drill bit is vibrated and detached from the bottom hole rock, the axial return spring releases energy, and the axial return spring pushes the rotating body 302 to protrude from the casing 301 along the helical groove 307, and tends to return to the initial position. Due to the protruding movement of the cushion teeth 304, when the drill bit falls back to the bottom of the well, the eccentric cushion teeth 304 bear pressure, thereby cushioning the drill bit and protecting the cutting teeth.

In the present embodiment, due to the existence of the helical groove 307 and the protrusion 308, the front inclination angle of the cushioning module 3 may be set to 0°, which reduces the difficulty of processing and installation.

In the present embodiment, the axial return spring is a compression spring, a high-elasticity rubber element, or a torsion spring, and the torsional restoring force of the torsion spring may make the rotating body 302 return to the free state position faster, and absorb the impact load in time effect.

EMBODIMENT 3

The present embodiment is basically the same as embodiment 2, the difference is that the reset mechanism is a hydraulic device.

As shown in FIG. 22, the hydraulic device comprises a first chamber 501, a second chamber 502, an intermediate valve seat 503, a first check valve 504, a second check valve 505, an energy storage element 506 and a reset piston 507. The first chamber 501 contains hydraulic oil. During the initial drilling, the cushion teeth 304 rotate under the action of the friction force of the formation rock, which drives the rotating body 302 to rotate, and the rotating body 302 moves upward along the helical groove 307. At the same time, the rotating body 302 compresses the hydraulic pressure in the first chamber 501. The oil flows into the second chamber 502 through the first check valve 504 with a smaller diameter, and the hydraulic oil in the second chamber 502 pushes the reset piston 507 to move and compress the energy storage element 506, so that the energy storage element 506 accumulates energy. The rotation speed of the rotating body 302 is relatively small in such process. When the drill bit is stably drilling, the cushion teeth 304 are in a stable equilibrium state. When the drill bit encounters an uneven stratum or a brittle stratum, the drill bit jumps up and down. When the drill bit jumps up, the friction between the cushion teeth 304 and the stratum is reduced, the stable and balanced working state is broken, and the compressed energy storage element 506 releases energy, pushes the reset piston 507 to compress the hydraulic oil in the second chamber 502, and makes it quickly enter the first chamber 501 through the second check valve 505 with a larger diameter, and the hydraulic oil in the first chamber 501 pushes the rotating body 302 to rapidly rotate in the opposite direction, so as to realize the quick reset of the cushion teeth 304.

EMBODIMENT 4

The preset embodiment is basically the same as Embodiment 3, and the difference is that the second chamber 502 communicates with the drilling fluid outside the drill bit.

As shown in FIG. 23, the drilling fluid enters the first chamber 501 from the second check valve 505 through the inner flow channel 10 of the blade, and pushes the rotating body 302 to be in a free state. When drilling starts, the cushion teeth 304 rotate along the helical groove 307 under the action of rock friction, and move into the casing 301 against the pressure in the first chamber 501. The first check valve 504 is opened, and the drilling fluid is discharged, When the drill bit is stably drilling, the internal and external pressures are balanced. If the drill bit vibrates up and down, the friction force and pressure between the cushion teeth 304 and the rock become smaller, so that the flat state of the liquid pressure in the first chamber 501 and the drilling fluid pressure outside the drill bit is broken, and the external drilling fluid pressure is greater than the first chamber 501. The drilling fluid pressure in the first chamber 501 pushes the second check valve 505 with a larger diameter into the first chamber 501, and pushes the rotating body 302 to rotate along the helical groove 307 and rapidly extend out of the casing 301, thereby achieving the purpose of absorbing shock pressure

EMBODIMENT 5

As shown in FIG. 24, a cavity 309 is provided between the casing 301 of the cushioning module 3 and the rotating body 302, a reset mechanism 303 is installed in the cavity, and a sealing ring 310 is disposed between the casing 301 and the rotating body 301. The casing 301 and the rotating body 302 are provided with raceway grooves, and the bearing and the rotating body are fixed and restrained in the axial direction by the balls 305. The cushion teeth 304 rotate under the action of rock friction, and drive the rotating body 302 to rotate, and the rotating body 302 squeezes the reset mechanism 303 in the cavity 309 and accumulates elastic energy. When the frictional force is reduced, the stored elastic energy is released, pushing the rotating body 302 and the cushion teeth 304 to rotate to the initial position. Alternatively, the reset mechanism 303 is a compression spring. In this solution, the stepped surface between the casing 301 and the rotating body 302 may also play a role of limit.

EMBODIMENT 6

This embodiment is basically the same as embodiment 5, and the difference is that, as shown in FIG. 25, the reset mechanism 303 is the hydraulic device 5.

The hydraulic device 5 comprises a first chamber 501, a second chamber 502, an intermediate valve seat 503, a first check valve 504, a second check valve 505, an energy storage element 506 and a reset piston 507. The first chamber 501 contains hydraulic oil. During initial drilling, when the cushion tooth 304 rotates under the action of the friction force of the formation rock, the same drives the rotating body 302 to rotate, and the rotating body 302 compresses the hydraulic oil in the first chamber 501 and flows into the second chamber 502 through the first check valve 504 with a smaller diameter. The hydraulic oil in the second chamber 502 pushes the reset piston 507 to move and compresses the energy storage element 506, so that the energy storage element 506 stores energy. During this process, the rotation speed of the rotating body 302 is small. When the drill bit is stably drilling, the cushion teeth 304 are in a stable equilibrium state. When the drill bit encounters an uneven stratum or a brittle stratum, the drill bit jumps up and down. When the drill bit jumps up, the friction between the cushion teeth 304 and the stratum is reduced, the stable and balanced working state is broken, and the compressed energy storage element 506 releases energy, pushes the reset piston 507 to compress the hydraulic oil in the second chamber 502, and makes it quickly enter the first chamber 501 through the second check valve 505 with a larger diameter, and the hydraulic oil in the first chamber 501 pushes the rotating body 302 to rapidly rotate in the opposite direction, so as to realize the quick reset of the cushion teeth 304.

Specifically, the energy storage element 506 may be a compression spring or a disc spring.

In this solution, the valve holes of the first check valve 504 and the second check valve 505 of the hydraulic reset device may also be opened on the end faces so as to communicate with the external chamber or flow channel.

EMBODIMENT 7

The present embodiment is basically the same as Embodiment 6, and the difference is that, in order to improve the reset speed of the rotating body 302 and the cushion teeth 304, two first chambers 501 are opened at the same time and two hydraulic devices 5 are correspondingly arranged. A compression spring is provided in the first chamber, as shown in FIG. 26.

EMBODIMENT 8

The present embodiment is basically the same as Embodiment 1, and the difference is that the cushion teeth 304 and the rotating body 302 are integrally constructed, and the casing 301 and the blade 1 are integrally constructed, that is, the rotating body 302 is directly installed on the blade 1, and a sealing ring 310 is arranged between the two, as shown in FIG. 27.

EMBODIMENT 9

As shown in FIG. 28, the present embodiment is basically the same as Embodiment 1 and Embodiment 3. The difference lies in that a gear 508 is provided on the rotating body 302, and the gear 508 is connected to the hydraulic device 5 by meshing with the rack 509. The rotation of the rotating body 302 drives the rack 509 to move through the gear 508 thereon, and interacts with the liquid between the hydraulic devices. The working process of the hydraulic device 5 is basically the same as that of Embodiment 3. In addition to the hydraulic device, in this solution, the rack 509 may also be connected to a compression spring, high-elasticity rubber or other high-elasticity material elements to achieve a reset effect.

The embodiments of the present disclosure described above and illustrated in the accompanying drawings do not limit the scope of the present disclosure, which is to be covered by the scope of the appended claims and their legal equivalents. Any equivalent embodiments are within the scope of this disclosure. Indeed, various modifications of the present disclosure, in addition to those shown and described herein, such as alternative useful combinations of the elements, will be apparent to those skilled in the art from the foregoing description. Such modifications and embodiments are within the scope of the appended claims and equivalents.

Claims

1. A diamond drill bit with a self-adaptive cushioning module, comprising a drill body (912) and a blade (1) extending from the drill body (912), the blade (1) being provided with cutting teeth (2), at least one cushioning module (3) being provided on the drill bit (910), characterized in that the cushioning module (3) is rotatably connected to the drill bit body (912), and the cushioning portion of the cushioning module (3) is eccentrically arranged relative to a rotation axis of the cushioning module (3);

when the cushioning portion of the cushioning module (3) in the initial position bears the impact force from the formation rock, the cushioning portion absorbs the impact load, reduces the impact force of the blade cutting teeth (2), and cushions the cutting teeth (2);

the cushioning portion of the cushioning module (3) is under the action of the force in contact with the bottom hole rock, and rotates relative to the cutting teeth (2) to perform a shrinking trend movement, so as to reduce or avoid the impact of the cushioning module (3) on the intrusion depth of the cutting teeth (2);

when the cushioning portion of the cushioning module (3) is out of contact with bottom hole rock or when the contact resistance torque is less than reset torque, under the action of a reset mechanism (303), the cushioning portion rotates to the initial position of the cushioning portion in a rotational manner, so as to realize a protruding tendency movement relative to the cutting teeth (2); the position of the cushioning portion relative to the cutting teeth (2) is raised, which plays a cushioning role for the subsequent impact of the cutting teeth (2).

2. The diamond drill bit with a self-adaptive cushioning module according to claim 1, characterized in that the cushioning module (3) is arranged on the blade (1) and is rotatably connected to the blade (1).

3. The diamond drill bit with a self-adaptive cushioning module according to claim 1, characterized in that when the cushioning module (3) is in the initial position, the height difference H between the highest point of the cushioning portion of the cushioning module (3) and the highest point of the cutting tooth (2) edge is: −D≤H≤D, where D is the diameter of the cutting tooth (2).

4. The diamond drill bit with a self-adaptive cushioning module according to claim 1, characterized in that the cushioning module (3) comprises a rotating body (302) and a cushion tooth (304), and the rotating body (302) is rotatablely installed in a base hole (11) of the blade (1), the cushion teeth (304) are eccentrically arranged with respect to the rotation axis of the rotating body (302) to form a cushioning portion, and the rotating body (302) is connected to the reset mechanism (303), so that the cushioning module (3) may be automatically reset after being rotated by an external force and when the external force disappears.

5. The diamond drill bit with a self-adaptive cushioning module according to claim 4, characterized in that the cushion teeth (304) are inlaid and fixed on the rotating body (302), or the cushion teeth (304) are freely rotatablely connected on the rotating body (302), or the cushion teeth (304) and the rotating body (302) are integrally formed.

6. The diamond drill bit with a self-adaptive cushioning module according to claim 4, characterized in that the cushion teeth (304) are spherical teeth, wedge teeth, conical teeth or PDC teeth.

7. The diamond drill bit with a self-adaptive cushioning module according to claim 4, characterized in that a casing (301) is provided between the rotating body (302) and the base hole (11), and the casing (301) is fixed on the blade (1), the rotating body (302) is installed in the casing (301), and the rotating body (302) forms a rotational connection with the casing (301).

8. The diamond drill bit with a self-adaptive cushioning module according to claim 1, characterized in that the cushioning module (3) is installed on the drill bit in which the PDC cutting structure is combined with other cutting structures comprising movable cutting structures.

9. The diamond drill bit with a self-adaptive cushioning module according to claim 1, characterized in that the front inclination angle of the cushioning module (3) is in the range of 0°<α≤60°, and the deflection angle is in the value range of −60°<β≤60°.

10. The diamond drill bit with a self-adaptive cushioning module according to claim 9, characterized in that the reset mechanism (303) is a torsion spring.

11. The diamond drill bit with a self-adaptive cushioning module according to claim 4, characterized in that the rotating body (302) of the cushioning module (3) performs a telescopic movement in the axial direction while rotating.

12. The diamond drill bit with a self-adaptive cushioning module according to claim 11, characterized in that the rotating body (302) is provided with a helical groove (307), and a protrusion (308) corresponding to the helical groove (307) is provided on the path of the axial movement of the rotating body (302).

13. The diamond drill bit with a self-adaptive cushioning module according to claim 11, characterized in that the reset mechanism (303) is a torsion spring, a compression spring or a hydraulic reset structure.