CN217538588U - Obtuse-angle multi-edge cutting tooth and PDC drill bit - Google Patents

Abstract

The utility model relates to an obtuse-angle multi-blade cutting tooth and a PDC drill bit. The obtuse-angle multi-blade cutting tooth comprises a tooth body, the upper end face of the tooth body is provided with a cutting surface, and the cutting surface comprises a cutting surface formed by connecting at least two cutting edges. The obtuse-angled cutting edge, the contour of the cutting edge is a straight line or a curve, the contour lines of the cutting edge are connected in turn to form an included angle A, or the tangent of the contour lines of the cutting edge at the intersection point forms an included angle A, the said The included angle A is an obtuse angle. The PDC bit includes the obtuse multi-edge cutter. The obtuse-angle multi-edge cutting teeth and PDC drill bit provided by the utility model aim to adjust the rock-breaking aggressiveness by changing the obtuse angle of the obtuse-angle cutting edge, enhance the rock-breaking stability, and reduce the initial tooth wear of the conventional drill bit in the rock-breaking process. phenomenon, prolong the service life of the cutting teeth, and reduce the occurrence of damage to the cutting teeth and even the bit body.

Description

Obtuse Multi-Flute Cutters and PDC Bits

technical field

The utility model relates to the technical field of drilling tools, in particular to an obtuse-angle multi-edge cutting tooth and a PDC drill bit.

Background technique

Polycrystalline Diamond Compact (PDC) bits are widely used in oil drilling and other fields due to their high ROP, high drilling efficiency and long service life, and are especially suitable for drilling in soft to medium-hard rock formations. The PDC teeth are composed of a polycrystalline diamond layer and a cemented carbide base. The traditional PDC teeth use cylindrical teeth, and each cylindrical PDC tooth forms the cutting profile of the drill. The cutting profile is different from the theoretical profile, which leads to the actual breakage of the drill The rock working state is quite different from the ideal design working condition, and it is difficult to analyze the working condition and wear and damage of the drill bit, which brings difficulties to the design optimization of the drill bit; in order to make the cutting profile closer to the theoretical design profile, it is necessary to densify the cylindrical teeth. When the teeth and cylindrical teeth are drilling, the contact arc between the teeth and the bottom hole rock turns the direct invasion into the envelope of the curve, which increases the contact area and weakens the eating (invasion) ability of the teeth and the drill bit.

The wear of PDC bit cutting teeth is the result of friction wear, spalling wear, adhesive wear and oxidation wear under the combined action of machinery, heat and chemistry, which is a very complex process. Among them, friction wear is a physical phenomenon that exists in any tool cutting process. With the continuous depletion of shallow oil and gas resources, oil and gas exploration and development are changing from conventional oil and gas reservoirs to low-permeability and unconventional oil and gas reservoirs, and from shallow to deep and ultra-deep layers, making drilling more and more difficult. In extremely hard, highly abrasive and hard plastic formations, conventional PDC bits have low ROP and short service life. Therefore, it is urgent to develop new PDC bits.

Utility model content

The purpose of the present invention is to provide an obtuse-angle multi-edge cutting tooth and a PDC drill bit to solve the technical problems mentioned in the above background art.

In order to achieve the above purpose, the present utility model provides the following technical solutions: an obtuse-angled multi-blade cutting tooth, comprising a tooth body, the upper end face of the tooth body is provided with a cutting surface, and the cutting surface includes a cutting surface connected by at least two cutting edges. The obtuse-angled cutting edge is formed, the contour of the cutting edge is a straight line or a curve, the contour lines of the cutting edge are sequentially connected to form an included angle A, or the tangent of the contour lines of the cutting edge at the intersection point forms an included angle A, the included angle A is an obtuse angle. By changing the obtuse angle of the obtuse cutting edge to adjust the rock-breaking aggression and enhance the rock-breaking stability, it can reduce the initial tooth wear of conventional drill bits during the rock-breaking process, prolong the wear life of the cutting teeth, and reduce the damage to the PDC teeth and even the bit body. .

As a preferred solution, the contour line of the cutting edge is a curve, and the radius of curvature of the curve is larger than the radius of the cutting surface.

As a preferred solution, the angle of the included angle A is set to be 105°≤A≤179°.

As a preferred solution, the range of the distance S from the contour of the obtuse cutting edge to the center of the original cutting edge is 0.2R≤S≤0.95R, where R is the radius or short diameter of the original cutting edge.

As a preferred solution, the range of the distance D between the two ends of the contour of the obtuse cutting edge is set to be 0.5R≤D≤2R, where R is the radius or short diameter of the original cutting edge.

As a preferred solution, the angle range of the obtuse angle B of the obtuse cutting edge corresponding to the obtuse cutting edge and the axial oblique angle B of the cutting surface is set to be 70°≤B≤105°.

The utility model also provides a technical solution for a PDC drill bit, which includes a drill bit body and several sets of blade wings connected to the upper end of the drill bit body. The tooth arrangement is the above-mentioned obtuse multi-edge cutting teeth.

As a preferred solution, the obtuse-angle multi-blade cutting teeth are arranged in the two-thirds radius area of the cross section of the drill bit body. During the drilling process, the wider the obtuse-angle multi-blade cutting teeth are set, the better the cutting profile of the drill bit. The closer to the design theoretical contour, the smaller the error in the design or optimization.

As a preferred solution, the obtuse-angle multi-blade cutting teeth are arranged in the half-radius area of the cross section of the drill bit body. Due to the large pressure on the core of the drill bit, the obtuse-angle multi-blade cutting teeth are arranged in its half Within one radius area, the penetration ability of the drill bit can be improved, and the drilling efficiency can be further improved.

As a preferred solution, the obtuse-angle multi-blade cutting teeth are radially continuously arranged on the blade, the radial arrangement overlap between the obtuse-angle multi-blade cutting teeth is greater than 0, and the obtuse-angle multi-blade cutting teeth are arranged in a radial direction. The overlap of the radial arrangement is less than 1, and the overlap of the radial arrangement between the obtuse-angle multi-edge cutting teeth is greater than 0 to ensure full coverage of the bottom of the well. Considering factors such as economy and aggression, the overlap of the radial arrangement should not be too high.

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

(1) By adopting the obtuse-angle multi-blade cutting teeth on the PDC bit, the obtuse-angle multi-blade cutting teeth and the rock contact surface are multi-straight lines or curves with a large curvature radius that form a certain angle with each other, aiming to change the obtuse-angle cutting edge by changing the obtuse-angle cutting edge. The obtuse angle adjusts the rock-breaking aggression, enhances the rock-breaking stability, reduces the initial tooth wear of conventional drill bits in the rock-breaking process, prolongs the service life of the cutting teeth, and reduces the damage to the cutting teeth and even the bit body.

(2) By adopting the obtuse-angle multi-edge cutting teeth, the radial cutting profile of the drill bit is more consistent with the radial tooth distribution profile, and the analysis data of the drill bit's working conditions and wear and damage conditions are more suitable for the design conditions, which is beneficial to the drill bit. Make design optimizations and improvements.

(3) Conventional PDC drills use scalloped teeth. In order to make the cutting profile closer to the theoretical design profile, the scalloped teeth need to be closely arranged on the radial tooth distribution diagram, and the tooth density of the cutting teeth is very high. The obtuse-angle multi-edge cutting tooth structure can reduce the number of teeth, and can reach or approach the theoretical design profile without the need for dense arrangement on the radial tooth layout, which can significantly reduce the number and density of teeth, and improve the rock breaking of the drill bit. efficiency.

(4) Compared with the circular cutting teeth, the cutting profile of the drill bit adopts the cutting teeth with obtuse cutting edges, which can make the load and cutting energy distribution between the teeth more balanced, realize the reasonable distribution of the crushing energy, and help the distribution The tooth design improves the rock breaking efficiency of the drill bit.

Description of drawings

Fig. 1 is the overall structure schematic diagram of PDC drill bit in the utility model;

Fig. 2 is the top view of PDC drill bit in the utility model;

3 is a schematic diagram of the partial arrangement of teeth of the PDC drill bit in the utility model;

4 is a schematic diagram of the structural parameters of the obtuse-angle multi-edge cutting tooth of Embodiment 1;

5 is a schematic diagram of the structural parameters of the obtuse-angle multi-edge cutting tooth of Embodiment 2;

6 is a schematic diagram of the structural parameters of the obtuse-angle multi-edge cutting tooth of Embodiment 3;

7 is a schematic diagram of the structural parameters of the obtuse-angled multi-edge cutting tooth of the fourth embodiment;

FIG. 8 is a schematic diagram of the structural parameters of the obtuse-angle multi-edge cutting tooth in Embodiment 5;

FIG. 9 is a schematic structural diagram of an obtuse-angle multi-edge cutting tooth in the present invention.

The meanings of the symbols in the figure are:

1. Drill body; 2. Blade; 3. Obtuse-angled multi-edge cutting teeth; 4. Cylindrical cutting teeth; 5. Tooth flank; 6. Obtuse-angled cutting edge; 7. Original cutting edge; 8. Cutting surface; 9. Tooth body.

Detailed ways

The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the implementations. example. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", The orientations or positional relationships indicated by "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. are based on those shown in the accompanying drawings The orientation or positional relationship is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limit.

Referring to FIGS. 1-3 , the present embodiment discloses a PDC drill bit, which includes a drill bit body 1 and several sets of blades 2 connected to the upper end of the bit body 1 , and several cutting teeth are arranged on the crown of the blade 2 . In the embodiment, the cutting teeth further include cylindrical cutting teeth 4 and obtuse-angled multi-edged cutting teeth 3 , and at least one cutting tooth in each set of blades 2 is set as an obtuse-angled multi-edged cutting tooth 3 . The cylindrical cutter 4 is a common cutter structure on a conventional PDC drill bit, and the structure thereof will not be repeated here.

Referring to FIG. 9, the obtuse-angled multi-edge cutting tooth 3 further includes a tooth body 9, the upper end face of the tooth body 9 is set as a cutting surface 8, and the cutting surface 8 includes an obtuse-angled cutting edge 6 formed by connecting at least two cutting edges. The contour line can be a straight line or a curve. When the contour lines of the cutting edge are all straight lines, the contour lines of the cutting edge are connected in turn to form an included angle A. When at least one of the contour lines of the cutting edge is a curve, the cutting edge At the intersection point, the tangent of the contour line forms an included angle A, the included angle A is set as an obtuse angle, the angle range of the included angle A is set as 105°≤A≤179°, and the included angle A is set too small, in the tip area of the tooth It is easy to produce stress concentration, which accelerates wear and even causes tooth breakage. Further, when the contour line of the cutting edge is set as a curve, the radius of curvature thereof is larger than the radius of the cutting surface 8, so as to better adjust the rock-breaking aggressiveness. That is, the obtuse-angle cutting edge 6 of the obtuse-angle multi-edge cutting tooth 3 is a multi-segment curve, or a combination of straight lines, curves, and multi-segment straight lines. The curvature of the contour of the edge 6 is smaller than the curvature of the original cutting edge 7 of the obtuse-angled multi-blade cutting tooth 3, which can better adjust the rock-breaking aggressiveness. The contour line of the cutting edge of the obtuse-angle multi-edge cutting tooth 3 is set as a multi-segment curve, which will make the rock surface uneven during the drilling process, which is conducive to local eating and scraping, thereby improving the rock breaking efficiency of the drill bit. This embodiment adjusts the rock-breaking aggressiveness by changing the obtuse angle of the obtuse-angled cutting edge 6 and enhances the rock-breaking stability, thereby reducing the initial tooth wear of conventional drill bits in the rock-breaking process, prolonging the wear life of the cutting teeth, and reducing the occurrence of damaged PDC teeth or even Case of drill body 1.

The tooth body 9 is made of polycrystalline diamond composite sheets, polycrystalline diamond composite teeth, impregnated diamond teeth (blocks), cubic boron carbide, cemented carbide teeth, or composite polycrystalline diamond and impregnated diamond.

In the obtuse-angle multi-edge cutting tooth 3, the distance S from the contour of the obtuse-angle cutting edge 6 to the center of the original cutting edge 7 is 0.2R≤S≤0.95R, and the wear resistance of the tooth can be adjusted, and R is the original cutting edge 7 radius or short diameter. The distance S is defined as: in the direction perpendicular to the line connecting the two ends of the obtuse cutting edge 6, the distance between the center of the circle of the original cutting edge 7 of the cutting tooth and the farthest point on the obtuse cutting edge 6 is S. In the obtuse-angled multi-edge cutting teeth 3, the range of the distance D between the two ends of the contour of the obtuse-angled cutting edge 6 is set to 0.5R≤D≤2R, which can reduce the initial tooth wear during the rock breaking process, and R is the original cutting edge 7 radius or short diameter.

Further, in the PDC drill bit, the obtuse-angle multi-blade cutting teeth 3 are arranged in the two-thirds radius area of the cross section of the drill bit body 1. During the drilling process, the wider the obtuse-angle multi-blade cutting teeth 3 are set, the better the cutting edge of the drill bit. The closer the profile is to the design theoretical profile, the smaller the error in the design or optimization. The wider the setting range of the obtuse-angled multi-edge cutting teeth 3, the stronger the aggressiveness of the drill bit and the higher the drilling efficiency. Preferably, the obtuse-angle multi-blade cutting teeth 3 are arranged in the half-radius area of the cross section of the drill bit body 1. Since the core of the drill bit bears a large pressure, the obtuse-angle multi-blade cutting teeth 3 are arranged in half of the cross-section of the drill bit body. In the radius area, the penetration ability of the drill bit can be improved, and the drilling efficiency can be further improved. Further, the obtuse-angle multi-blade cutting teeth 3 are continuously arranged radially on the blade 2, the radial arrangement overlap between the obtuse-angle multi-blade cutting teeth 3 is greater than 0, and the obtuse-angle multi-blade cutting teeth 3 are arranged in a radial direction. The overlapping degree of the radial arrangement between the two cutters is less than 1, and the overlapping degree of the radial arrangement between the obtuse-angle multi-edge cutting teeth 3 is greater than 0 to ensure full coverage of the bottom hole. Considering factors such as economy and aggression, the radial arrangement overlaps The degree should not be too high. Preferably, the overlapping degree of radial arrangement between the obtuse-angle multi-blade cutting teeth 3 is greater than 0, and the radial arrangement overlapping degree between the obtuse-angle multi-blade cutting teeth 3 is preferably less than 0.5.

The angle range of the obtuse angle B of the obtuse cutting edge 6 corresponding to the obtuse cutting edge 6 of the obtuse multi-edge cutting tooth 3 is set to be 70°≤B≤105°. The strength is higher, but at the same time, the angle of the axial bevel should not be too large, so as not to reduce the feeding ability.

Example 1:

Figure 4 is a schematic diagram of an obtuse-angled multi-blade cutting tooth 3 set as a double-line cutting edge. The obtuse-angle cutting edge 6 is composed of two cutting edges whose contour lines are straight lines, and the contour lines of the cutting edges are connected in turn to form an included angle A. , the value of the included angle A is 170°, the value of the radius or short diameter R of the original cutting edge 7 is 6.72mm, the value of the tooth height H is 13mm, the obtuse angle cutting edge 6 of the obtuse multi-edge cutting tooth 3 corresponds to the flank The value of the axial bevel angle B between 5 and the cutting surface 8 is 90°, and the value of the distance S from the contour of the obtuse cutting edge 6 to the center of the original cutting edge 7 is 0.7R, that is, 4.70mm. The PDC bit provided in this embodiment has good stability and high cutting tooth breaking efficiency while ensuring the feeding capacity, and is suitable for plastic formations and soft formations.

Embodiment 2:

As shown in FIG. 5 , the difference between this embodiment and the first embodiment is that the contour lines of the cutting edges are sequentially connected to form an included angle A, the value of the included angle A is 105°, and the contour of the obtuse-angled cutting edge 6 reaches the original cutting edge. The value of the distance S of the center of the circle of 7 is 0.9R, that is, 6.05mm. The obtuse-angled cutting edges 6 of the obtuse-angled multi-edge cutting teeth 3 of the present embodiment form a small angle at the intersection point, and the PDC bit has a stronger ability to eat into the rock.

Embodiment three:

As shown in FIG. 6 , the difference between this embodiment and the first embodiment is that the obtuse-angled cutting edge 6 of the obtuse-angled multi-edge cutting tooth 3 is composed of three cutting edges whose contour lines are all straight lines, and the contour lines of the cutting edges are sequentially The connection forms an included angle A, the value of the included angle A is all 135°, and the value of the distance S from the contour of the obtuse cutting edge 6 to the center of the original cutting edge 7 is 0.85R, that is, 5.71 mm. The PDC bit provided in this embodiment has a strong ability to eat into rocks, and has better stability, life and wear resistance.

Embodiment 4:

As shown in FIG. 7 , the difference between this embodiment and the first embodiment is that the obtuse-angled cutting edge 6 of the obtuse-angled multi-edge cutting tooth 3 is composed of a cutting edge with a straight line and a curved edge with a curved line. , the value of the included angle A formed by the tangent of the contour line of the cutting edge at the intersection point is 170°. The PDC bit provided in this embodiment is suitable for drilling in soft formations, and the larger the included angle is, the larger the crushing volume of the cutting action is.

Embodiment 5:

As shown in FIG. 8 , the difference between this embodiment and the first embodiment is that the obtuse-angled cutting edge 6 of the obtuse-angled multi-edge cutting tooth 3 is composed of two cutting edges whose contour lines are curved, and the contour lines of the cutting edges intersect at the intersection. The value of the angle A formed by the tangent at the point is 173°. This embodiment is suitable for drilling in plastic formations and soft formations.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Under the premise of the spirit and scope, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the claimed invention. The claimed scope of the present invention is defined by the appended claims and their equivalents.

Claims (10)

1. The utility model provides an obtuse angle multiple-cutting-edge cutting tooth, includes the tooth body, its characterized in that, the up end of tooth body is provided with the cutting face, the cutting face includes the obtuse angle cutting edge that forms by connecting two at least blades, the contour line of blade is straight line or curve, the contour line of blade connects gradually and forms contained angle A, or its tangent line of contour line in the crossing point department of blade forms contained angle A, contained angle A is the obtuse angle.

2. The obtuse multi-edge cutting tooth of claim 1 wherein the contour of said edge is a curve having a radius of curvature greater than the radius of the cutting face.

3. The obtuse multi-edge cutting tooth according to claim 1, wherein the angle of the included angle A is set to 105 ° ≦ A ≦ 179 °.

4. The obtuse multi-edged cutting tooth as set forth in claim 1 wherein the distance S from the contour of the obtuse cutting edge to the center of the original cutting edge ranges from 0.2 R.ltoreq.S.ltoreq.0.95R, R being the radius or minor diameter of the original cutting edge.

5. The obtuse multi-edge cutting tooth according to claim 1, wherein the distance D between two end points of the profile of the obtuse cutting edge is set to 0.5R ≦ D ≦ 2R, R being the radius or minor diameter of the original cutting edge.

6. The obtuse multi-edge cutting tooth of claim 1 wherein the angular range of the axial oblique angle B of the tooth side corresponding to said obtuse cutting edge to the cutting face is set to 70 ° B105 °.

7. A PDC drill bit, including the bit body and several groups of blades connected to upper end of bit body, the crown of the said blade distributes several cutting teeth, characterized by that, each group of blades has at least one cutting tooth to set up as the multi-blade cutting tooth of obtuse angle of any one of claims 1-6.

8. The PDC bit of claim 7, wherein the obtuse angle multi-bladed cutting teeth are disposed within a two-thirds radius region of the cross-section of the bit body.

9. The PDC bit of claim 7 wherein the obtuse angle multi-bladed cutter is disposed within a half radius region of a cross-section of the bit body.

10. The PDC bit of claim 7, wherein the obtuse angle multi-edged cutters are arranged in a radially continuous pattern on the blades, wherein the radial overlap between the obtuse angle multi-edged cutters is greater than 0 and less than 1.

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