CN211851669U

CN211851669U - PDC drill bit

Info

Publication number: CN211851669U
Application number: CN201922113369.4U
Authority: CN
Inventors: 张富成; 孙辉; 赵全民; 周波; 卓鲁斌
Original assignee: China National Petroleum Corp; CNPC Engineering Technology R&D Co Ltd
Current assignee: China National Petroleum Corp; CNPC Engineering Technology R&D Co Ltd
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-11-03
Anticipated expiration: 2029-11-29

Abstract

The utility model provides a PDC drill bit, this PDC drill bit includes: the PDC drill bit comprises a core blade and outer cone blades which are distributed around the circumference of the PDC drill bit, wherein the core blade is provided with a gauge structure and a core mounting surface provided with composite sheet cutting teeth; maximum outer diameter R of outer contour of core mounting surface_maxAnd minimum outer diameter R of inner contour of outer cone mounting surface_minSatisfies the following conditions: r_max≤(0.9·R_{Gauge protection}) And R is_min≥(0.3·R_{Gauge protection}). Through the utility model discloses, alleviated the PDC drill bit among the prior art when the drilling of soft stratum, the easy slope that takes place causes the technical problem that well deviation exceeds standard.

Description

PDC drill bit

Technical Field

The utility model relates to a technical field of oil drilling especially relates to a PDC drill bit.

Background

PDC drill bits are widely used in drilling and rock breaking. The shearing strength of the rock is smaller than the compressive strength, the rock breaking mechanism of the PDC drill bit is mainly shearing, and the PDC drill bit is used for drilling, so that higher mechanical drilling speed can be obtained by providing smaller drilling pressure. In the drilling process, the PDC drill bit has unbalanced force and is influenced by the fluctuation of the reactive torque, and the PDC drill bit is easy to incline when drilling in a soft stratum, so that the well deviation of a well hole exceeds the standard and the quality of the well body is influenced.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a PDC drill bit to alleviate the PDC drill bit among the prior art when soft stratum is bored, the easy slope that takes place causes the technical problem that well deviation exceeds standard.

The above object of the present invention can be achieved by the following technical solutions:

the utility model provides a PDC drill bit, include: the PDC drill bit comprises a core blade and outer cone blades which are distributed around the circumference of the PDC drill bit, wherein the core blade is provided with a gauge protection structure and a core mounting surface provided with composite sheet cutting teeth;

a maximum outer diameter R of an outer contour of the core installation surface_maxAnd a minimum outer diameter R of an inner contour of the outer cone mounting surface_minSatisfies the following conditions:

R_max≤(0.9·R_{gauge protection})，

And R is_min≥(0.3·R_{Gauge protection})。

In a preferred embodiment, the core blades are provided with blade recesses, which are located outside the core mounting surface.

In a preferred embodiment, the gage structure of the core blade is the same as the gage structure of the outer cone blade.

In a preferred embodiment, the gauge structure includes a gauge face and at least two gauge teeth secured to the gauge face.

In a preferred embodiment, the gauge surface is provided with an alloy column groove, and the gauge teeth are fitted in the alloy column groove in an interference fit manner.

In a preferred embodiment, the PDC bit includes 3 core blades and 3 outer cone blades, and the core blades and the outer cone blades are alternately distributed in sequence around a circumference of the PDC bit.

In a preferred embodiment, each of said outer cone blades is provided with 3 of said composite sheet cutting teeth; 3 the core blade is including the first core blade, second core blade and the third core blade that distribute in proper order, be equipped with 2 on the first core blade compound piece cutting teeth, second core blade with be equipped with 3 on the third core blade compound piece cutting teeth.

In a preferred embodiment, the core blades have a first incident face and a first back-cut face on either side of the core mounting face, the first incident face and the first back-cut face being disposed obliquely with respect to the axis of the PDC bit.

In a preferred embodiment, the outer cone blades have a second attack and back-cut surface on both sides of the outer cone mounting surface, the second attack and back-cut surface being arranged obliquely with respect to the PDC bit axis.

In a preferred embodiment, the PDC bit has a nozzle on the front face of the bit crown.

In a preferred embodiment, the number of nozzles is 6.

In a preferred embodiment, auxiliary cutting teeth are provided on the first and second cutting-in surfaces, respectively.

The utility model discloses a characteristics and advantage are:

in the PDC drill bit, the distribution area of the composite sheet cutting teeth on the core blade is limited to R_max≤(0.9· R_{Gauge protection}) Within the range of (2), the distribution density of the composite sheet cutting teeth of the core blade is reduced, the number of the composite sheet cutting teeth is reduced, and meanwhile, the single teeth of the core blade are deeper to bite into the stratum, so that the attack performance is stronger, the PDC drill bit is favorable for drilling in a soft stratum at high speed, and the rock breaking and cutting efficiency is improved; the distribution area of the composite sheet cutting teeth on the outer cone blade is limited to R_min≥(0.3·R_{Gauge protection}) Within the scope, when guaranteeing that the gauge structure of PDC drill bit has great area of contact with the wall of a well, reduce the compound piece cutting teeth of outer cone position and the compound piece cutting teeth repeated cutting stratum of core position to reduce this PDC drill bit and take place the slope when drilling, played control well deviation, improve the effect of well bore quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a top view of a PDC blade provided by the present invention;

FIG. 2 is a first isometric view of the PDC blade shown in FIG. 1;

FIG. 3 is a second isometric view of the PDC blade shown in FIG. 1;

FIG. 4 is an elevation view of a PDC blade provided by the present invention;

FIG. 5 is a side view of the PDC blade shown in FIG. 4;

FIG. 6 is a side view of the PDC blade shown in FIG. 4.

The reference numbers illustrate:

10. a core blade; 100. a core mounting face; 110. a first incident plane; 120. a first back cut plane;

11. a first core blade; 12. a second core blade; 13. a third core blade; 14. a blade recess;

20. an outer cone blade; 200. an outer cone mounting surface; 210. a second incident plane; 220. a second back section;

21. a first outer cone blade; 22. a second outer cone blade; 23. a third outer cone blade;

30. a gauge protection structure; 31. a gauge surface; 32. gauge protection teeth; 321. a first gauge tooth; 322. a second gauge tooth;

40. a composite sheet cutting tooth; 50. auxiliary cutting teeth;

60. a nozzle;

71. a bit crown; 72. a joint structure.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

The utility model provides a PDC drill bit, as shown in fig. 1 and fig. 4-6, the PDC drill bit comprises a drill bit crown portion 71 and a joint structure 72, the drill bit crown portion 71 is provided with core blades 10 and outer cone blades 20, and the core blades 10 and the outer cone blades 20 are circumferentially distributed around the axis of the PDC drill bit; the core blade 10 is provided with a gauge protection structure 30 and a core mounting surface 100 provided with composite sheet cutting teeth 40, and the outer cone blade 20 is provided with a gauge protection structure 30 and an outer cone mounting surface 200 provided with composite sheet cutting teeth 40; the core mounting surface 100 includes a top surface of the core blade 10, the outer cone mounting surface 200 includes a top surface of the outer cone blade 20, and a maximum outer diameter R of an outer contour of the core mounting surface 100_maxAnd Tao Xie Gu anMinimum outside diameter R of inner contour of mounting surface 200_minSatisfies the following conditions:

R_max≤(0.9·R_{gauge protection}) And R is_min≥(0.3·R_{Gauge protection})。

In the PDC drill bit, the distribution region of the composite sheet cutting teeth 40 on the core blade 10 is defined at R_max≤(0.9·R_{Gauge protection}) Within the range of (1), the distribution density of the composite sheet cutting teeth 40 of the core blade 10 is reduced, the number of the composite sheet cutting teeth 40 is reduced, and meanwhile, the single teeth of the core blade 10 are deeply eroded into the stratum, so that the attack performance is strong, the PDC drill bit is favorable for drilling in the soft stratum at high speed, and the rock breaking and cutting efficiency is improved; the distribution of the composite sheet cutting teeth 40 on the outer cone blades 20 is defined at R_min≥(0.3·R_{Gauge protection}) Within the scope, when guaranteeing that this PDC drill bit's gauge structure 30 and the wall of a well have great area of contact, reduce the compound piece cutting teeth 40 of outer cone position and the compound piece cutting teeth 40 repeated cutting stratum of core position to reduce this PDC drill bit and take place the slope when drilling, played control well deviation, improve the effect of well bore quality.

In one embodiment of the present invention, the core blade 10 is provided with a blade groove 14, and the blade groove 14 is located outside the core mounting surface 100. The outer profile of the core mounting surface 100 is defined by the wing grooves 14, and the wing grooves 14 improve the drilling fluid field of the drill core, thereby facilitating the discharge of cut rock debris.

As shown in fig. 2, the PDC bit includes 3 core blades 10 and 3 outer cone blades 20, and the core blades 10 and the outer cone blades 20 are alternately distributed in sequence around the circumference of the PDC bit.

Further, each outer cone blade 20 is provided with 3 composite sheet cutting teeth 40; each of the 3 core blades 10 includes a first core blade 11, a second core blade 12 and a third core blade 13 which are sequentially distributed, the first core blade 11 is provided with 2 composite sheet cutting teeth 40, and the second core blade 12 and the third core blade 13 are provided with 3 composite sheet cutting teeth 40, so that each of the composite sheet cutting teeth 40 can be uniformly contacted with the formation rock, and the stress is more uniform. Preferably, the composite sheet cutting tooth 40 is welded in the tooth socket through a welding process, and the tail part of the composite sheet cutting tooth 40 is subjected to a reinforcing protection effect through a surfacing process.

Referring to fig. 3, along the inside-out direction, the first outer cone blade 21 is sequentially provided with a composite sheet cutting tooth 1a, a composite sheet cutting tooth 1b and a composite sheet cutting tooth 1c, the second core blade 12 is sequentially provided with a composite sheet cutting tooth 2a, a composite sheet cutting tooth 2b and a composite sheet cutting tooth 2c, the second outer cone blade 22 is sequentially provided with a composite sheet cutting tooth 3a, a composite sheet cutting tooth 3b and a composite sheet cutting tooth 3c, the third core blade 13 is sequentially provided with a composite sheet cutting tooth 4a, a composite sheet cutting tooth 4b and a composite sheet cutting tooth 4c, the third outer cone blade 23 is sequentially provided with a composite sheet cutting tooth 5a, a composite sheet cutting tooth 5b and a composite sheet cutting tooth 5c, and the first core blade 11 is sequentially provided with a composite sheet cutting tooth 6a and a composite sheet cutting tooth 6 b.

Each composite sheet cutting tooth 40 has a respective first reference point; specifically, the leading end surface of the composite sheet cutter 40 is its cutting face, and the first reference point is the center of the cutting face of the composite sheet cutter 40.

A plane passing through the axis of the PDC bit is used as a reference plane of the PDC bit. Each composite sheet cutting tooth 40 has a respective second reference point; the angle between the plane formed by the second reference point and the axis of the PDC bit and the reference plane is used as the position angle of the composite sheet cutting element 40. Preferably, the second reference point is the apex of the cutting face of the composite sheet cutter 40 (i.e., the highest point of the composite sheet cutter 40 shown in fig. 4 and 5).

In the end projection of the PDC bit, the first reference point and the second reference point of the composite sheet cutting tooth 40 on the outer cone blade 20 are both positioned in the range limited by the outer cone installation surface 200; the first and second reference points of the composite sheet cutter 40 on the core blade 10 are both located within the confines of the core mounting surface 100.

In one specific embodiment, the angular position of each composite sheet cutting tooth 40 is set as follows; the distance between the first reference point of each composite blade 40 and the axis of the PDC bit is set as follows.

Tooth number	Angle of position	Distance/mm
			1a	70°	59
1b	73°	81
			1c	72°	107
2a	12°	13
			2b	11°	47
2c	13°	65
			3a	315°	63
3b	317°	79
			3c	318°	104
4a	260°	11
			4b	263°	43
4c	267°	67
			5a	204°	69
5b	207°	83
			5c	211°	106
6a	152°	42
			6b	155°	68

The position of each composite sheet cutting tooth 40 is determined according to the above table. By adopting the asymmetrical structure for tooth arrangement, the cutting amount of each composite sheet cutting tooth 40 is equal or approximately equal in the drilling process, the teeth are uniformly loaded, the service life of a drill bit is prolonged, and the drilling efficiency is improved.

In other embodiments, the angle of the position of each composite blade 40 may be shifted up or down by 2.5 ° based on the data in the table above, ensuring that the PDC bit has good drilling efficiency and well bore quality.

In one embodiment of the present invention, referring to fig. 3, the core blade 10 has a first incident surface 110 and a first back-cut surface 120 located at both sides of the core mounting surface 100, and the first incident surface 110 and the first back-cut surface 120 are disposed obliquely with respect to an axis of the PDC drill bit.

Outer cone blades 20 have second incident faces 210 and second back-cut faces 220 on either side of outer cone mounting face 200, second incident faces 210 and second back-cut faces 220 being disposed obliquely with respect to the axis of the PDC bit.

As shown in FIG. 2, the gauge structure 30 comprises a gauge face 31 and at least two gauge teeth 32 fixed on the gauge face 31, and the gauge teeth 32 rotate with the drill bit to circumferentially rotate and shear the deviated well wall so as to keep the well wall smooth and regular. Preferably, a plurality of gauge teeth 32 in the gauge structure 30 are distributed in an inclined straight line as a whole, as shown in fig. 2 and 4, at least two gauge teeth 32 include a first gauge tooth 321 and a second gauge tooth 322, and an included angle between a connecting line of a center of an end face of the first gauge tooth 321 and a center of an end face of the second gauge tooth 322 and an axis of the PDC drill bit is 45 ° for cutting and trimming a well wall at different depth positions. Further, the gauge structures 30 of the core blades 10 are the same as the gauge structures 30 of the outer cone blades 20, that is, in each gauge structure 30, the distribution mode of the gauge teeth 32 is the same, which is beneficial to the contact between the gauge teeth 32 and the well wall, improves the contact area, and reduces the well deviation.

Further, the gauge surface 31 is provided with an alloy column groove, and the gauge teeth 32 are embedded in the alloy column groove in an interference fit manner. Preferably, the outer portion of gauge teeth 32 is protected by a weld overlay process to enhance wear and impact resistance.

The front end face of the bit crown 71 of the PDC bit is provided with a nozzle 60; preferably, referring to fig. 2, the number of the nozzles 60 is 6, which accelerates the discharge of the rock debris, enhances the cooling and cleaning of the composite sheet cutting teeth 40, and simultaneously prevents the repeated cutting of the rock debris at the bottom of the well, thereby improving the cutting efficiency. The first incident surface 110 and the second incident surface 210 are respectively provided with auxiliary cutting teeth 50.

In one embodiment of the present invention, the bit crown 71 is made of a monolithic alloy structural steel by machining equipment such as a lathe, a milling machine, etc. The lower end of the drill bit crown part 71 is provided with a thread structure, the drill bit crown part 71 is connected with the joint structure 72 through threads, and the welding process is adopted for strengthening connection so as to ensure the torque resistance.

The above description is only for the embodiments of the present invention, and those skilled in the art can make various changes or modifications to the embodiments of the present invention according to the disclosure of the application document without departing from the spirit and scope of the present invention.

Claims

1. A PDC bit, comprising: the PDC drill bit comprises a core blade and outer cone blades which are distributed around the circumference of the PDC drill bit, wherein the core blade is provided with a gauge protection structure and a core mounting surface provided with composite sheet cutting teeth;

R_max≤(0.9·R_{gauge protection})，

And R is_min≥(0.3·R_{Gauge protection})。

2. The PDC bit of claim 1 wherein the core blades have blade recesses therein, the blade recesses being located outside of the core mounting face.

3. The PDC bit of claim 1, wherein the gage structure of the core blades is the same as the gage structure of the outer cone blades.

4. The PDC bit of claim 1, wherein the gage structure comprises a gauge face and at least two gage teeth secured to the gauge face.

5. The PDC bit of claim 4 wherein the gauge face is provided with an alloy post groove, the gauge teeth being interference fit embedded in the alloy post groove.

6. The PDC bit of claim 1, wherein the PDC bit comprises 3 of the core blades and 3 of the outer cone blades, and wherein the core blades and the outer cone blades are sequentially alternately distributed about a circumference of the PDC bit.

7. The PDC bit of claim 6 wherein each of the outer cone blades is provided with 3 of the composite sheet cutters;

3 the core blade is including the first core blade, second core blade and the third core blade that distribute in proper order, be equipped with 2 on the first core blade compound piece cutting teeth, second core blade with be equipped with 3 on the third core blade compound piece cutting teeth.

8. The PDC bit of claim 1 wherein the core blades have first face-in and first back-out faces on either side of a core mounting face, the first face-in and first back-out faces being disposed obliquely to an axis of the PDC bit.

9. The PDC bit of claim 8, wherein the outer cone blades have a second face-in face and a second back-out face on either side of the outer cone mounting face, the second face-in face and the second back-out face being disposed obliquely to an axis of the PDC bit.

10. The PDC bit of claim 1, wherein the PDC bit has a nozzle on a front face of a bit crown.

11. The PDC bit of claim 10, wherein the number of nozzles is 6.

12. The PDC bit of claim 9 wherein each of the first and second confronting faces has auxiliary cutting teeth thereon.