CN113107371A - Self-excitation shaft-impacting and induced unloading coupling rock breaking drill bit and drilling speed increasing method - Google Patents

Abstract

Translated fromChinese

本发明公开了一种自激轴冲与诱导卸荷耦合破岩钻头，包括钻头本体；钻头本体的钻井端设置外部环形破岩部，外部环形破岩部的头端中部内凹形成中心破岩部；外部环形破岩部沿圆周方向设置有若干刀翼和若干镶嵌有牙轮切削齿的牙轮；刀翼的径向外端面上沿母线方向设置若干外环切削齿；中心破岩部的底端面设置中心切削齿；钻头本体上设置钻头喷嘴。本发明还公开了一种自激轴冲与诱导卸荷耦合破岩钻井提速方法。本发明可以自动产生轴向冲击提高钻头整体破岩速度、可以耦合诱导卸荷效果进一步强化破岩效率、可以发挥复合切削提升卸荷效果，从而将钻井速度提升到一个更高水平。

The invention discloses a self-excited axial punching and induced unloading coupled rock breaking drill bit, which comprises a drill bit body; an outer annular rock breaking part is arranged at the drilling end of the drill bit body; The annular rock-breaking part is provided with a number of blade blades and a number of cones inlaid with cone cutting teeth along the circumferential direction; the radial outer end face of the blade blade is provided with a number of outer ring cutting teeth along the generatrix direction; the bottom end face of the central rock-breaking part is provided with a center cutting Teeth; a drill nozzle is provided on the drill body. The invention also discloses a speed-up method for rock-breaking drilling coupled with self-excited axial thrust and induced unloading. The invention can automatically generate axial impact to improve the overall rock-breaking speed of the drill bit, further enhance the rock-breaking efficiency by coupling inducing unloading effect, and exert the effect of composite cutting, lifting and unloading, thereby raising the drilling speed to a higher level.

Description

Self-excitation shaft-impacting and induced unloading coupling rock breaking drill bit and drilling speed increasing method

Technical Field

The invention belongs to the technical field of drilling engineering, and particularly relates to a self-excited axial-percussion and induced unloading coupled rock breaking drill bit and a drilling acceleration method.

Background

The improvement of the drilling speed is a research hotspot in the field of drilling engineering, and the improvement of the rock breaking efficiency is one of the main ways of improving the drilling speed. Rotary impact rock breaking, combined cutting rock breaking and shaft bottom induced unloading rock breaking are three effective methods for improving rock breaking efficiency at present. However, the impact force relied on by the existing rotary impact rock breaking is generated by a special tool, and the existence of the rotary impact tool influences the track control operation, reduces the hydraulic energy of the drill bit and brings extra underground risks; the existing tool for realizing the composite cutting and rock breaking is a composite drill bit (lion tiger beast), and accidents such as tooth breaking, gear wheel falling, central core digging and the like still occur in a multi-interlayer stratum and a hard and difficult stratum; the existing drill bit used for inducing unloading and breaking rock at the bottom of a well improves the rock breaking efficiency to a certain extent, but the unloading effect is to be further improved.

Based on the problems, the self-excitation axial impact and induced unloading coupled rock breaking drill bit and the drilling speed increasing method can automatically generate axial impact to improve the overall rock breaking speed of the drill bit, can further enhance the rock breaking efficiency by coupling the induced unloading effect, and can play a combined cutting and lifting unloading effect, so that the drilling speed is increased to a higher level.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a self-excited axial-percussion and induced unloading coupled rock breaking drill bit and a drilling speed increasing method.

In order to achieve the purpose, the invention adopts the following technical scheme:

the self-excited shaft-impacting and induced unloading coupled rock breaking drill bit comprises a drill bit body;

the drilling end of the drill bit body is provided with an external annular rock breaking part, and the middle part of the head end of the external annular rock breaking part is inwards concave along the axial direction of the drill bit to form a central rock breaking part in a circular groove;

the outer annular rock breaking part is provided with a plurality of blades and a plurality of cones embedded with cone cutting teeth along the circumferential direction;

the blades extend from the edge of the central rock breaking part to the side wall of the drill bit body;

the gear wheel is in rotary connection with a corresponding shaft neck on the outer annular rock breaking part;

a plurality of outer ring cutting teeth are arranged on the radial outer end surface of the blade wing along the direction of a generatrix;

the bottom end surface of the central rock breaking part is provided with a central cutting tooth;

the drill bit body is provided with a drill bit nozzle, and the drill bit nozzle is communicated with a drill bit inner cavity inside the drill bit body through a nozzle flow channel.

Preferably, the vertical connecting surface of the blade facing the central rock breaking part is in a cylindrical surface structure;

the vertical connecting surfaces of all the blades are positioned on the same axial cylindrical surface, and the central axis of the axial cylindrical surface and the central axis of the central rock breaking part are collinear with the central axis of the drill bit body;

the diameter of the axial cylindrical surface is consistent with that of the circular groove of the central rock breaking part.

Preferably, the sum h of the height of the vertical connecting surface in the axial direction of the drill bit and the height of the side wall of the circular groove of the central rock breaking part in the axial direction of the drill bit is 0.2D-2D;

the diameter D of the circular groove of the central rock breaking part is 0.2D-0.8D, and D is the diameter of the drill bit.

Preferably, the envelope l of the outermost cutting profile formed by the cutting teeth of the roller cone is₁Is higher than the envelope line l of the outermost cutting profile formed by the cutting teeth of the outer ring on the blade₂。

Preferably, the drill bit nozzle comprises an outer ring nozzle arranged on the outer annular rock breaking part on one side of the cutter wing and a central nozzle arranged on the bottom end face of the central rock breaking part;

the chip removal channel that sets up in the broken rock portion of outside annular link up with the chip removal channel that the broken rock portion of center set up mutually.

Preferably, the outer ring cutting teeth and the central cutting teeth are PDC teeth.

Preferably, the PDC tooth is a multi-blade PDC cutting tooth, the end portion of the body of the multi-blade PDC cutting tooth is a cylinder, the rock breaking end of the multi-blade PDC cutting tooth comprises a plurality of layers of cutting tooth surfaces which are arranged from the center outwards along the radial direction and distributed in a step shape, and the cutting tooth surfaces of the layers are parallel.

Preferably, the PDC tooth is ancient coin shape PDC cutting tooth, the tooth body tip of ancient coin shape PDC cutting tooth is the cylinder, the broken rock end of ancient coin shape PDC cutting tooth is ARC structure, ARC structure's radial outer end sets up a plurality of cutting faces, form the crooked arc cutting edge to PDC tooth center direction between cutting face and the ARC structure.

The invention also provides a self-excitation shaft-impact and induced unloading coupling rock breaking drilling speed increasing method.

A self-excitation shaft-impact and induced unloading coupled rock breaking drilling acceleration method is used for drilling based on a self-excitation shaft-impact and induced unloading coupled rock breaking drill bit, and comprises the following steps:

1) the external annular rock breaking part firstly contacts the well bottom, the drill bit integrally rotates under the action of the bit pressure torque, and the cone autorotates in the process of rotating along with the drill bit; the autorotation of the cone causes the single tooth and the double tooth of the cutting teeth of the cone to touch the ground alternately, and the single tooth and the double tooth cause the reciprocating motion of the drill bit along the axial direction in the process of touching the ground alternately, so that the high-frequency axial impact of the drill bit on the well bottom is realized, and the cone and the outer ring cutting teeth act together under the high-frequency axial impact to accelerate the crushing of rocks at the outer ring part of the drill bit;

2) along with the proceeding of rock breaking of the outer ring cutting teeth and the cone, rock columns are formed in the central rock breaking part area, and the bottom hole pressure is effectively released;

3) along with the process of rock breaking, the central cutting teeth contact the rock column and break the rock column under the action of the weight-on-bit torque;

4) in the process of drilling by breaking rocks with the drill bit, the nozzle flow passage sprays drilling fluid through the drill bit nozzle to clean the drill bit and carries rock debris to the ground through the corresponding debris discharge passage.

Preferably, the cone and the outer ring cutting teeth act together under the high-frequency axial impact by the following process:

when the cutter teeth of the cone on the cone are changed from double-tooth grounding to single-tooth grounding due to autorotation, the drill bit is lifted integrally, the outer ring cutter teeth on the blades leave the bottom of the well, and the cutter teeth on the cone grounding break rock;

when the cutting teeth of the cone on the cone are changed from single tooth landing to double tooth landing due to autorotation, the whole bit is impacted downwards, the outer ring cutting teeth on the blades land, and the impact shears the bottom of the well after the stress of the cone is released.

The invention has the beneficial effects that:

(1) the invention utilizes the inner recess of the central rock breaking part and the arrangement of the vertical connecting surface on the blade in the center of the drill bit to form an inner recessed cylindrical area, and the formation of the area can release the rock stress at the central part of the well bottom in the drilling process, thereby realizing induced unloading.

(2) According to the invention, single and double teeth generated by the rotation of the gear wheel are alternatively grounded to form axial vibration of the drill bit, so that high-frequency axial impact is formed, and the overall rock breaking speed is increased; meanwhile, the stress of the hard-to-drill part of the outer ring can be released by the rugged well bottom formed by the cone.

(3) The invention realizes composite cutting by the combination of the outer ring cutting teeth on the blades, the cone cutting teeth on the cone and the central cutting teeth, and further improves the drilling speed.

(4) Compared with the existing cutting teeth only provided with a single-layer cutting tooth surface, the multi-blade PDC cutting teeth have the advantage that the service life of the teeth is prolonged.

(5) Compared with the existing cutting teeth, the ancient coin-shaped PDC cutting teeth can bear high-strength impact, are resistant to grinding and reduce rock breaking energy consumption and difficulty through plough cutting.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application.

FIG. 1 is a schematic top view of a self-excited axial-percussion and induced unloading coupled rock breaking drill bit according to the present invention;

FIG. 2 is a schematic front view of the self-excited axial-percussion and induced unloading coupled rock breaking drill bit of the present invention;

FIG. 3 is a schematic view of the relationship between the outer annular rock breaking portion, the central rock breaking portion, the blades and the cone in the present invention;

FIG. 4 is a schematic diagram of rock breaking during landing of a single tooth of the roller cone of the present invention;

FIG. 5 is a schematic diagram of rock breaking during landing of the teeth of the cone of the present invention;

FIG. 6 is a schematic representation of a multi-bladed PDC cutter having a planar cutting surface in accordance with the present invention;

FIG. 7 is a schematic view of a multi-bladed PDC cutter of the present invention with the cutting tooth surface being a cone;

FIG. 8 is a schematic view of a multi-edged PDC cutting tooth in the present invention when the cutting tooth surface is a pyramidal face;

FIG. 9 is a schematic perspective view of a structure of a coin-shaped PDC cutter inembodiment 3 of the present invention;

FIG. 10 is a schematic top view of a structure of a coin-shaped PDC cutter inembodiment 3 of the present invention;

FIG. 11 is a schematic front view of a structure of a ancient coin-shaped PDC cutting tooth inembodiment 3 of the invention;

wherein:

1-an outer annular rock breaking portion,

2-central rock breaking, 201-central cutting teeth, 202-bottom end face;

3-blades, 301-radial outer end face, 302-outer ring cutting teeth and 303-vertical connecting face;

4-cone, 401-cone cutting teeth;

5-an outer ring nozzle, wherein,

6-a central nozzle;

701-circular plane, 702-annular plane;

801-cone, 802-ring cone;

901-pyramid, 902-annular pyramid;

1001-cambered surface structure, 1002-cutting surface and 1003-cambered cutting edge.

Detailed Description

It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.

In the present invention, terms such as "connected" and "connecting" should be interpreted broadly, and mean either a fixed connection or an integral connection or a detachable connection; may be directly connected or indirectly connected through an intermediate. The specific meanings of the above terms in the present invention can be determined according to specific situations by persons skilled in the relevant scientific or technical field, and are not to be construed as limiting the present invention.

The invention is further illustrated with reference to the following figures and examples.

Example 1:

as shown in fig. 1-2, the self-excited axial-percussion and induced unloading coupled rock breaking drill bit comprises a drill bit body;

the drilling end of the drill bit body is provided with an external annularrock breaking part 1, and the middle part of the head end of the external annularrock breaking part 1 is inwards recessed along the axial direction of the drill bit to form a centralrock breaking part 2 in a circular groove; wherein, thebottom end surface 202 of the centralrock breaking part 2 is a plane, or an inward concave conical surface with the vertex positioned at one side far away from the bottom direction, or an outward convex conical surface with the vertex positioned at one side close to the bottom direction, and can be in other shapes;

the outer annularrock breaking part 1 is provided with a plurality ofblades 3 and a plurality ofcones 4 embedded withcone cutting teeth 401 along the circumferential direction; theblades 3 and thecones 4 may be alternately arranged as shown in fig. 1, or may be arranged in other required forms, and the arrangement manner between theblades 3 and thecones 4 is not limited in the present application;

theblade 3 extends from the edge of the centralrock breaking part 2 to the side wall of the drill bit body;

thecone 4 is in rotary connection with a corresponding shaft neck on the outer annularrock breaking part 1; specifically, a bit leg is fixedly arranged on the outer annularrock breaking part 1 in the middle between theadjacent blades 3, one end of the bit leg is welded with the drill bit body into a whole, and a shaft neck is arranged at the other end of the bit leg; thecone 4 is sleeved on the journal to realize the rotary connection with the journal, and thecone 4 is axially locked on the journal, so that thecone 4 can rotate around the corresponding journal;

a plurality of outerring cutting teeth 302 are arranged on the radialouter end surface 301 of theblade 3 along the generatrix direction;

the bottom end surface of the centralrock breaking part 2 is provided with acentral cutting tooth 201; specifically, a plurality of central blades are arranged on thebottom end surface 202 of the centralrock breaking part 2 along the circumferential direction, and a plurality ofcentral cutting teeth 201 are arranged on the end surface of each central blade along the bus direction;

the drill bit body is provided with a drill bit nozzle, the drill bit nozzle is communicated with a drill bit inner cavity inside the drill bit body through a nozzle flow channel, and the drill bit inner cavity is communicated with a drilling fluid flow channel.

Preferably, the vertical connectingsurface 303 of theblade 3 facing the centralrock breaking portion 2 is in a cylindrical surface structure;

the vertical connectingsurfaces 303 of all theblades 3 are positioned on the same axial cylindrical surface, and the central axis of the axial cylindrical surface and the central axis of the centralrock breaking part 2 are collinear with the central axis of the drill bit body;

the diameter of the axial cylindrical surface is consistent with that of the circular groove of the centralrock breaking part 2.

Specifically, one end of thevertical connection surface 303 extends to the head end of the radialouter end surface 301 of thecorresponding blade 3 along the axial direction of the drill bit, and the other end of thevertical connection surface 303 extends to the head end of the circular groove of the centralrock breaking portion 2 along the axial direction of the drill bit.

According to the self-excited axial shock and induced unloading coupled rock breaking drill bit, when a stratum with higher ground stress is drilled, the outerring cutting teeth 302 on theblades 3 and thecone cutting teeth 401 on thecone 4 firstly break rock at the outer ring part of the drill bit, and broken rock debris is discharged into a borehole annulus through the corresponding debris discharge channels along with drilling fluid sprayed by theouter discharge nozzles 5.

Thebottom end surface 202 of the centralrock breaking part 2 is concave, and the vertical connectingsurfaces 303 of theblades 3 are connected to the concave circular grooves, so that concave cylindrical regions are formed in the region surrounded by the vertical connectingsurfaces 303 of all theblades 3 and the concave region of the centralrock breaking part 2, namely, concave and convex stepped structures are formed; during drilling of the formation, a "rock pillar" is formed within the concave cylindrical region. When the drill meets a region with higher ground stress, the rock drillability is poor, the rock pillar formed in the drilling process of the stepped structure effectively reduces or even eliminates the influence of the ground stress on the rock drillability, the rock drillability is greatly improved, and a stress unloading region is formed at the rock pillar part, so that the core digging situation can be effectively prevented. Thecentral cutting teeth 201 crush the middle rock pillar, and the formed rock debris is carried and washed by the drilling fluid sprayed by thecentral nozzle 6 and then discharged into the annular space of the borehole through the corresponding debris discharge channel.

Preferably, as shown in fig. 3, the sum h of the height of the vertical connectingsurface 303 in the axial direction of the drill and the height of the circular groove side wall of the centralrock breaking portion 2 in the axial direction of the drill is 0.2D-2D;

the diameter D of the circular groove of the centralrock breaking part 2 is 0.2D-0.8D, and D is the diameter of the drill bit.

In the size range, the rock breaking specific work of the drill bit is low, and the mechanical energy consumed for breaking the rock of unit volume is less, so that the service life of the drill bit is prolonged.

Preferably, thecone 4 has an envelope of the outermost cutting profile l formed by the cuttingteeth 401 of the cone₁Is higher than the envelope line l of the outermost cutting profile formed by the outerring cutting teeth 302 on theblade 3₂As shown in fig. 3, such that theroller cutter teeth 401 onroller cone 4 contact the bottom hole first; in FIG. 3, |₁' is₁Envelope, l, mapped to one side of blade 3₁' higher than₂Thus l₁Higher than l₂。

In the drilling process, the external annularrock breaking part 1 firstly contacts the bottom of a well, the drill bit integrally rotates under the action of the bit pressure torque, and thecone 4 autorotates in the process of rotating along with the drill bit; in the self-rotation process, the cuttingteeth 401 of thecone 4 are alternatively grounded by single teeth and double teeth;

when thecutter teeth 401 on thecone 4 are changed from the double-tooth grounding to the single-tooth grounding due to autorotation, the drill bit is lifted integrally, the outerring cutter teeth 302 on theblades 3 leave the bottom of the well, and thecutter teeth 401 on theroller 4 grounding break rock, as shown in fig. 4;

when thecutter teeth 401 of thecone 4 are changed from single tooth grounding to double tooth grounding due to autorotation, the whole bit is impacted downwards, the outerring cutter teeth 302 on theblades 3 are grounded, and the bottom of the well after the stress of the crushingcone 4 is released is impacted and sheared, as shown in fig. 5;

therefore, the reciprocating motion of the drill bit in the axial direction is realized by alternately landing the single teeth and the double teeth of thecutter teeth 401, so that the high-frequency axial impact of the drill bit on the well bottom is realized, and the crushing of rocks at the outer ring part of the drill bit is accelerated.

Preferably, the drill bit nozzle comprises anouter ring nozzle 5 arranged on the outer annularrock breaking part 1 on one side of theblade 3 and acentral nozzle 6 arranged on the bottom end face of the centralrock breaking part 2; the structure ensures that drilling fluid sprayed from the nozzles can effectively clean and cool the cutting teeth at the main part of the rock to be broken, and avoids the repeated breaking phenomenon caused by the accumulation of rock debris;

the chip removal channel that sets up in the broken rock portion ofoutside annular 1 link up with the chip removal channel that the brokenrock portion 2 of center set up mutually.

Drilling fluid is provided by the nozzle flow passage, theouter ring nozzle 5 and thecentral nozzle 6; a chip removal channel arranged in the external annularrock breaking part 1 is used for removing rock chips generated by drilling of the outerring cutting teeth 302 and the rollercone cutting teeth 401 into the annulus of the borehole; thecentral breaking portion 2 is provided with a debris removal channel for removing debris generated by drilling thecentral cutting tooth 201 into the borehole annulus.

Preferably, theouter ring cutter 302 and thecenter cutter 201 are PDC teeth.

Example 2:

on the basis of theembodiment 1, the PDC teeth are multi-blade PDC cutting teeth, the end parts of the tooth bodies of the multi-blade PDC cutting teeth are cylindrical, the rock breaking ends of the multi-blade PDC cutting teeth comprise a plurality of layers of cutting tooth surfaces which are arranged outwards from the center in the radial direction and are distributed in a step shape, and the cutting tooth surfaces of all layers are parallel.

When the cutting tool is used, the cutting tooth surface at the head end of the center firstly contacts with the rock to play a cutting role; when the rock is too hard or used for a period of time, the cutting tooth surface of the central part is damaged and loses cutting effect, and the next layer of cutting tooth surface can play a cutting effect. Compare the cutting teeth that only has the individual layer cutting flank of tooth than current, the setting of this application multiple blade PDC cutting teeth has promoted the life of tooth.

The cutting tooth surface is a plane, a conical surface or a pyramid surface, and can be in other shapes.

Specifically, as shown in fig. 6, the cutting tooth surface is a flat surface, the cutting tooth surface located at the head end of the center is a circularflat surface 701, and the remaining cutting tooth surfaces distributed in a stepped manner are annularflat surfaces 702.

Specifically, as shown in fig. 7, the cutting tooth surface is a conical surface, the cutting tooth surface located at the head end of the center includes two intersectingconical surfaces 801, the remaining cutting tooth surfaces distributed in a stepped manner are annularconical surfaces 802,

specifically, as shown in fig. 8, the cutting tooth surface is a pyramidal surface, the cutting tooth surface located at the head end of the center includes a plurality ofpyramidal surfaces 901 intersecting at a point, the remaining cutting tooth surfaces distributed in a step shape are annularpyramidal surfaces 902, the extension surfaces of the annularpyramidal surfaces 902 of the same layer also intersect at a point, and the point where thepyramidal surfaces 901 intersect and the point where the annularpyramidal surfaces 902 intersect are both located on the central axis of the PDC tooth. The configuration of the cutting tooth surface at the most head end of the center includes 3 pyramidal faces 901 as shown in fig. 8, and may include other numbers of pyramidal faces, which are not listed here.

Example 3:

on the basis ofembodiment 1, as shown in fig. 9-11, the PDC tooth is a guju-shaped PDC cutting tooth, the tooth body end portion of the guju-shaped PDC cutting tooth is a cylinder, the rock breaking end of the guju-shaped PDC cutting tooth is an arc-shapedstructure 1001, the radial outer end of the arc-shapedstructure 1001 is provided with a plurality of cuttingsurfaces 1002, and an arc-shapedcutting edge 1003 bending towards the center direction of the PDC tooth is formed between the cuttingsurfaces 1002 and the arc-shapedstructure 1001.

Compared with the existing cutting teeth, the ancient coin-shaped PDC cutting teeth can bear high-strength impact, are resistant to grinding and reduce rock breaking energy consumption and difficulty through plough cutting.

Example 4:

a self-excited shaft-impulse and induced unloading coupled rock breaking drilling speed increasing method is used for drilling based on the self-excited shaft-impulse and induced unloading coupled rock breaking drill bit in theembodiment 1, and the drilling speed increasing method comprises the following steps:

1) the external annularrock breaking part 1 firstly contacts a well bottom, the drill bit integrally rotates under the action of the bit pressure torque, and thecone 4 autorotates in the process of rotating along with the drill bit; the autorotation of thecone 4 causes the single-tooth and double-tooth landing of thecone cutting teeth 401 to alternately occur, the single-tooth and double-tooth alternate landing process causes the reciprocating motion of the drill bit along the axial direction, so that the high-frequency axial impact of the drill bit on the well bottom is realized, and thecone 4 and the outerring cutting teeth 302 act together under the high-frequency axial impact to accelerate the crushing of rocks at the outer ring part of the drill bit; meanwhile, the stress of the hard-to-drill part of the outer ring can be released by utilizing the rugged well bottom formed by the gear wheel;

specifically, the process ofcone 4 andouter ring cutter 302 coacting at high frequency axial impacts is:

when thecutter teeth 401 on thecone 4 are changed from the double-tooth grounding to the single-tooth grounding due to autorotation, the drill bit is lifted integrally, the outerring cutter teeth 302 on theblades 3 leave the bottom of the well, and thecutter teeth 401 on theroller 4 grounding break rock, as shown in fig. 4;

when thecutter teeth 401 of theroller cone 4 are changed from single tooth landing to double tooth landing due to autorotation, the whole bit is impacted downwards, the outerring cutter teeth 302 on theblades 3 land, and the impact shears the bottom of the well after the stress of the crushingroller cone 4 is released, as shown in fig. 5.

2) Along with the process of breaking rock by the outerring cutting teeth 302 and thecone 4, rock columns are formed in the area of the centralrock breaking part 2, and the bottom hole pressure is effectively released;

3) as the rock breaking progresses, thecentral cutting tooth 201 contacts the rock column, and thecentral cutting tooth 201 breaks the rock column under the action of the weight-on-bit torque;

4) in the process of drilling by breaking rocks with the drill bit, the nozzle flow passage sprays drilling fluid through the drill bit nozzle to clean the drill bit and carries rock debris to the ground through the corresponding debris discharge passage.

The invention utilizes the inner concave of the centralrock breaking part 2 and the arrangement of the vertical connectingsurface 303 on theblade 3 in the center of the drill bit to form an inner concave cylindrical area, and the formation of the area can release the rock stress at the central part of the well bottom in the drilling process, thereby realizing induced unloading; single teeth and double teeth generated by the rotation of thegear wheel 4 are alternatively landed to form axial vibration of the drill bit, so that high-frequency axial impact is formed, and the overall rock breaking speed is improved; the combination of the outerring cutting teeth 302 on theblades 3, thecone cutting teeth 401 on thecone 4 and thecentral cutting teeth 201 is utilized to realize composite cutting, and the drilling speed is further improved.

Although the embodiments of the present invention have been described with reference to the accompanying drawings, it is not intended to limit the present invention, and it should be understood by those skilled in the art that various modifications and changes may be made without inventive efforts based on the technical solutions of the present invention.

Claims (10)

Translated fromChinese

1.自激轴冲与诱导卸荷耦合破岩钻头，其特征是，包括钻头本体；1. A self-excited axial punch and an induced unloading coupling rock-breaking bit, characterized in that it comprises a bit body;所述钻头本体的钻井端设置外部环形破岩部，所述外部环形破岩部的头端中部沿钻头轴向内凹形成呈圆形凹槽的中心破岩部；The drilling end of the drill bit body is provided with an outer annular rock breaking part, and the middle part of the head end of the outer annular rock breaking part is concave inward along the axial direction of the drill bit to form a central rock breaking part in the form of a circular groove;所述外部环形破岩部沿圆周方向设置有若干刀翼和若干镶嵌有牙轮切削齿的牙轮；The outer annular rock-breaking part is provided with a plurality of blades and a plurality of cones inlaid with the cutting teeth of the cones along the circumferential direction;所述刀翼由中心破岩部的边缘延伸至钻头本体的侧壁；The blade extends from the edge of the central rock breaking part to the side wall of the drill body;所述牙轮与外部环形破岩部上的相应轴颈进行转动连接；The roller is rotatably connected with the corresponding journal on the outer annular rock breaking part;所述刀翼的径向外端面上沿母线方向设置若干外环切削齿；A plurality of outer ring cutting teeth are arranged along the generatrix direction on the radial outer end face of the blade;所述中心破岩部的底端面设置中心切削齿；The bottom end face of the central rock-breaking portion is provided with central cutting teeth;所述钻头本体上设置钻头喷嘴，所述钻头喷嘴通过喷嘴流道与钻头本体内部的钻头内腔相连通。The drill bit body is provided with a drill bit nozzle, and the drill bit nozzle communicates with the drill bit inner cavity inside the drill bit body through the nozzle flow channel.2.如权利要求1所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述刀翼面向中心破岩部的竖直连接面呈柱面结构；2. The self-excited axial punching and induced unloading coupling rock-breaking bit according to claim 1, wherein the vertical connecting surface of the blade facing the central rock-breaking portion is cylindrical;所有刀翼的竖直连接面位于同一个轴向圆柱面上，所述轴向圆柱面的中心轴线、中心破岩部的中心轴线均与钻头本体的中心轴线共线；The vertical connecting surfaces of all blades are located on the same axial cylindrical surface, and the central axis of the axial cylindrical surface and the central axis of the central rock-breaking portion are collinear with the central axis of the drill body;所述轴向圆柱面的直径与中心破岩部圆形凹槽的直径一致。The diameter of the axial cylindrical surface is consistent with the diameter of the circular groove of the central rock breaking part.3.如权利要求2所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述竖直连接面在钻头轴向方向的高度与中心破岩部圆形凹槽侧壁在钻头轴向方向的高度之和h为0.2D～2D；3. The self-excited axial punching and induced unloading coupled rock breaking drill bit according to claim 2, wherein the height of the vertical connecting surface in the axial direction of the drill bit and the side wall of the circular groove of the central rock breaking part are at The sum of the heights in the axial direction of the drill bit is 0.2D ~ 2D;所述中心破岩部圆形凹槽的直径d为0.2D～0.8D，D为钻头直径。The diameter d of the circular groove of the central rock breaking part is 0.2D-0.8D, and D is the diameter of the drill bit.4.如权利要求1所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述牙轮上牙轮切削齿所形成的最外切削轮廓包络线l₁高于刀翼上外环切削齿所形成的最外切削轮廓包络线l₂。4. The self-excited shaft punch and induced unloading coupled rock-breaking bit according to claim 1, wherein the outermost cutting contour envelope_l1 formed by the upper cone cutter teeth is higher than the cutter The outermost cutting contour envelope l₂ formed by the outer ring cutting teeth on the wing.5.如权利要求1所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述钻头喷嘴包括设置在刀翼一侧外部环形破岩部上的外环喷嘴、设置在中心破岩部底端面上的中心喷嘴；5 . The self-excited axial punch and induced unloading coupled rock breaking drill bit according to claim 1 , wherein the drill nozzle comprises an outer ring nozzle arranged on the outer annular rock breaking part on one side of the blade, and is arranged in the center. 6 . The central nozzle on the bottom end face of the rock breaking section;所述外部环形破岩部内设置的排屑通道与中心破岩部设置的排屑通道相贯通。The chip removal channel provided in the outer annular rock breaking part communicates with the chip removal channel provided in the central rock breaking part.6.如权利要求1所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述外环切削齿、中心切削齿均为PDC齿。6 . The self-excited shaft punch and induced unloading coupling rock-breaking bit according to claim 1 , wherein the outer ring cutting teeth and the central cutting teeth are both PDC teeth. 7 .7.如权利要求6所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述PDC齿为多刃PDC切削齿，所述多刃PDC切削齿的齿身端部呈圆柱体，所述多刃PDC切削齿的破岩端包括若干层由中心沿径向向外设置的呈阶梯状分布的切削齿面，各层切削齿面相平行。7. The self-excited shaft punch and induced unloading coupling rock-breaking bit according to claim 6, wherein the PDC teeth are multi-edge PDC cutting teeth, and the tooth body ends of the multi-edge PDC cutting teeth are in the shape of a A cylinder, the rock-breaking end of the multi-blade PDC cutting tooth includes several layers of cutting tooth surfaces arranged radially outward from the center in a stepped distribution, and the cutting tooth surfaces of each layer are parallel.8.如权利要求6所述的自激轴冲与诱导卸荷耦合破岩钻头，其特征是，所述PDC齿为古币形PDC切削齿，所述古币形PDC切削齿的齿身端部呈圆柱体，所述古币形PDC切削齿的破岩端呈弧面结构，所述弧面结构的径向外端设置若干切削面，所述切削面与弧形结构之间形成向PDC齿中心方向弯曲的弧形切削刃。8. The self-excited shaft punch and induced unloading coupling rock-breaking bit according to claim 6, wherein the PDC teeth are ancient coin-shaped PDC cutting teeth, and the tooth body end of the ancient coin-shaped PDC cutting teeth The part is cylindrical, the rock-breaking end of the ancient coin-shaped PDC cutting teeth is in an arc structure, the radial outer end of the arc structure is provided with several cutting surfaces, and the PDC teeth are formed between the cutting surfaces and the arc structure. Arc-shaped cutting edge curved in the center direction.9.自激轴冲与诱导卸荷耦合破岩钻井提速方法，其特征是，基于如权利要求1～8任一所述的自激轴冲与诱导卸荷耦合破岩钻头进行钻井，所述钻井提速方法包括以下步骤：9. A method for speeding up rock-breaking drilling coupled with self-excited axial thrust and induced unloading, characterized in that drilling is performed based on the self-excited axial thrust and induced unloading coupled rock-breaking drill bit according to any one of claims 1 to 8, said The drilling speed-up method includes the following steps:1)外部环形破岩部首先接触井底，在钻压扭矩的作用下钻头整体旋转，牙轮随钻头转动的过程中进行自转；牙轮的自转导致牙轮切削齿单齿、双齿着地交替出现，单、双齿交替着地过程中引起钻头沿轴向的往复运动，进而实现钻头对井底的高频轴向冲击，在该高频轴向冲击下牙轮与外环切削齿共同作用加快对钻头外环部位岩石的破碎；1) The outer annular rock-breaking part first contacts the bottom of the well, and the bit rotates as a whole under the action of the WOB torque, and the cone rotates with the drill bit; , the reciprocating motion of the drill bit in the axial direction is caused during the alternate landing of the single and double teeth, thereby realizing the high-frequency axial impact of the drill bit on the bottom of the well. Breaking of the rock at the outer ring of the drill bit;2)随着外环切削齿、牙轮破岩的进行，在中心破岩部区域内形成岩石柱，有效释放了井底压力；2) With the rock breaking progress of the outer ring cutting teeth and roller cones, a rock column is formed in the central rock breaking area, which effectively releases the bottom hole pressure;3)随着破岩的进行，中心切削齿接触岩石柱，在钻压扭矩的作用下中心切削齿对岩石柱进行破碎；3) As the rock breaking progresses, the central cutting teeth contact the rock column, and the central cutting teeth break the rock column under the action of the weight-on-bit torque;4)在钻头破岩钻进过程中，喷嘴流道通过钻头喷嘴喷射钻井液清洗钻头，并将岩屑通过相应的排屑通道携带至地面。4) During the rock-breaking and drilling process of the drill bit, the nozzle flow channel sprays drilling fluid through the drill bit nozzle to clean the drill bit, and carries the cuttings to the ground through the corresponding chip removal channel.10.如权利要求9所述的自激轴冲与诱导卸荷耦合破岩钻井提速方法，其特征是，在高频轴向冲击下牙轮与外环切削齿共同作用的过程为：10. The self-excited axial impact and the coupling of induced unloading and coupling of rock-breaking drilling speed-up method as claimed in claim 9, characterized in that, under the high-frequency axial impact, the process of the joint action of the cone and the outer ring cutter is:牙轮上牙轮切削齿因自转由双齿着地变为单齿着地时，钻头整体上提，刀翼上的外环切削齿离开井底，牙轮上着地的牙轮切削齿破岩；When the cutting teeth on the cone on the cone change from double-tooth landing to single-tooth landing due to rotation, the drill bit is lifted as a whole, the outer ring cutting teeth on the blade leave the bottom of the well, and the cone cutting teeth touching the ground on the cone break the rock;牙轮上牙轮切削齿因自转由单齿着地变为双齿着地时，钻头整体向下冲击，刀翼上的外环切削齿着地，冲击剪切破碎牙轮应力释放后的井底。When the upper cone cutting teeth on the cone change from single-tooth landing to double-tooth landing due to rotation, the drill bit impacts downward as a whole, and the outer ring cutting teeth on the blade touch the ground, impacting and shearing the bottom hole after the stress of the cone is released.

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