CN220551065U - PDC drill bit - Google Patents

Abstract

The utility model relates to a PDC drill bit, which comprises a drill bit body and a plurality of cutting blades, wherein each cutting blade is provided with a plurality of PDC teeth, all PDC teeth comprise first PDC teeth with the same size and second PDC teeth with the same size, the size of the first PDC teeth is smaller than that of the second PDC teeth, the center line of the drill bit body is taken as an axis, the cutting blades in the area with the radius being half of the radius of the drill bit body are provided with the first PDC teeth, and the total number of the first PDC teeth is larger than or equal to the total number of the second PDC teeth in the area. According to the utility model, through the cooperation of the first PDC teeth with small size and the second PDC teeth with large size, the drilling speed of the drill bit in soft stratum is considered, the rock breaking efficiency of the drill bit in hard stratum is ensured, the stratum adaptability of the drill bit is greatly improved, and especially in soft and hard staggered stratum, the drilling adaptability of the drill bit is obviously improved.

Description

PDC drill bit

Technical Field

The utility model belongs to the technical field of drilling equipment, and particularly relates to a PDC drill bit.

Background

Along with the continuous deep exploration and development of various oil and gas fields in China, the exploration and development targets are changed from shallow oil and gas reservoirs with single lithology change, poor cementing quality and softness into deep oil and gas reservoirs with complex lithology change, frequent interleaving of hardness and softness, heterogeneity and difficult drilling. While the PDC teeth of the PDC drill bit commonly used in oilfield drilling are generally cylindrical, when the PDC drill bit breaks rock, the PDC teeth are pressed into (invaded) stratum by the bit pressure, and the rock is scraped and broken under the rotation drive of the drill bit body. In general, the smaller the PDC tooth size (referring to the diameter size of the cylinder), the easier it is to invade the formation. But the smaller the PDC tooth size, the smaller the amount of scraping rock breaking at scraping, and the smaller the tooth coverage area. Therefore, when drilling in softer stratum, the PDC teeth with larger size are generally adopted to increase the rock scraping and breaking amount of the PDC teeth, so as to improve the drilling efficiency of the soft stratum; when drilling into hard formations, smaller size PDC teeth are typically employed to enhance the ability and depth of penetration of the PDC teeth into the formation to increase the rate of drilling. However, the PDC teeth of the commonly used PDC drill bit are single in tooth arrangement and have a certain brittleness, such as deep complex lithology strata like formations frequently staggered when drilling, soft (or hard) interlayers, heterogeneous formations and the like, and the adaptability of the PDC teeth is poor, and the PDC teeth are mainly characterized by low rock breaking efficiency of the drill bit and slow mechanical drilling speed, and the PDC teeth are easy to damage, so that the drill bit is frequently started and replaced, the drilling efficiency is low, the drilling period is long, and the progress of deep hydrocarbon reservoir exploration and development is influenced.

The prior art discloses a seven-blade PDC drill bit, which comprises a drill bit matrix, wherein the drill bit basically comprises a drill bit crown, and a first blade, a second blade, a third blade, a fourth blade, a fifth blade, a sixth blade and a seventh blade are distributed on the circumference of the drill bit crown. The PDC teeth of the drill bit are easy to damage when the drill bit is used for drilling deep complex rock formations, so that the rock breaking efficiency is low, and the mechanical drilling speed is low.

Disclosure of Invention

In order to solve all or part of the problems, the utility model aims to provide a PDC drill bit, and the adaptability of the PDC drill bit to stratum is enhanced through the arrangement of first PDC teeth and second PDC teeth with different sizes.

According to one aspect of the utility model, there is provided a PDC bit comprising a bit body and a plurality of cutting blades, each of the cutting blades being provided with a plurality of PDC teeth, all of the PDC teeth comprising a first type of PDC teeth of the same size and a second type of PDC teeth of the same size, the first type of PDC teeth being smaller than the second type of PDC teeth in size.

Further, the first type PDC teeth are arranged on the cutting blades in the area with the center line of the drill bit body as an axis and the radius of one half of the radius of the drill bit body.

Further, in the region, the total number of the first type PDC teeth is greater than or equal to the total number of the second type PDC teeth.

Further, in the region, there is one PDC tooth of the second type, and at least one PDC tooth of the first type is equidistant from the center line of the bit body and the second type is equidistant from the center line of the bit body.

Further, for a first type of PDC teeth and a second type of PDC teeth which are equidistant, the rake angle of the first type of PDC teeth is smaller than the rake angle of the second type of PDC teeth.

Further, at least one of the cutting blades is simultaneously provided with the first type PDC teeth and the second type PDC teeth, and at least a part of the first type PDC teeth and the second type PDC teeth are alternately arranged on the cutting blade, and the total number of the PDC teeth which are alternately arranged is more than half of the total number of the PDC teeth on the cutting blade.

Further, at least one of the cutting blades is provided with only the first type of PDC teeth, and at least one of the cutting blades is provided with only the second type of PDC teeth.

Further, the novel high-strength composite material further comprises at least one type of PDC teeth, wherein the size of any one PDC tooth is unequal to the size of the first type of PDC teeth and the size of the second type of PDC teeth, and the type of PDC teeth has more than one size.

Further, the cutting blades include a plurality of long cutting blades uniformly distributed in the circumferential direction of the drill bit body, short cutting blades are arranged between two adjacent long cutting blades, the minimum distances from each long cutting blade to the center line of the drill bit body are equal, the minimum distances from each short cutting blade to the center line of the drill bit body are equal, and the minimum distances from each long cutting blade to the center line of the drill bit body are smaller than the minimum distances from each short cutting blade to the center line of the drill bit body.

Further, each cutting blade comprises a cutting blade first section and a cutting blade second section, the plurality of cutting blade first sections are uniformly distributed in the circumferential direction of the drill bit body, the cutting blade second sections are connected to one end of the cutting blade first sections extending into the stratum, and the PDC teeth are arranged on the cutting blade second sections.

According to the technical scheme, the PDC drill bit provided by the utility model has the following beneficial effects:

the first type PDC teeth and the second type PDC teeth with different sizes are arranged, so that the adaptability of the PDC drill bit to stratum is enhanced. When the soft stratum is drilled, the second PDC teeth with larger size can improve the scraping and rock breaking amount of the drill bit and ensure the drilling speed of the drill bit in the soft stratum; when drilling in a hard stratum, the first PDC teeth with smaller sizes keep the invasion capacity and aggressiveness of the drill bit, and the rock breaking efficiency of the drill bit in the hard stratum can be improved; therefore, the drill bit disclosed by the utility model not only considers the drilling speed of the drill bit in soft stratum, but also ensures the rock breaking efficiency of the drill bit in hard stratum, greatly improves the stratum adaptability of the drill bit, and particularly obviously improves the drilling adaptability of the drill bit in soft and hard staggered stratum.

Drawings

FIG. 1 is a schematic diagram of a PDC bit in accordance with an embodiment of the present utility model;

FIG. 2 is a schematic view of radial tooth placement of PDC teeth;

FIG. 3 is a schematic illustration of PDC tooth rake angle;

FIG. 4 is a schematic view of a PDC bit in accordance with an embodiment of the present utility model;

FIG. 5 is a schematic representation of a PDC bit in accordance with an embodiment of the present utility model;

the reference numerals in the drawings are: bit body 1, cutting blades 2, long cutting blades 21, short cutting blades 22, first type PDC teeth 3, second type PDC teeth 4, cutting contour 5, center line 6 of bit body, normal 7 of cutting contour.

Detailed Description

For a better understanding of the objects, structures and functions of the present utility model, a PDC bit of the present utility model is described in further detail below with reference to the accompanying drawings.

As shown in fig. 1, the PDC drill bit according to the embodiment of the present utility model includes a drill bit body 1 and a plurality of cutting blades 2, each cutting blade 2 is provided with a plurality of PDC teeth, all PDC teeth include a first type PDC tooth 3 with the same size and a second type PDC tooth 4 with the same size, the size of the first type PDC tooth 3 is smaller than the size of the second type PDC tooth 4, and for PDC teeth in a plane perpendicular to the center line of the drill bit body, the distance from the end of the second type PDC tooth 4 with a large size to the center line of the drill bit body is greater than the distance from the end of the first type PDC tooth 3 with a small size to the center line of the drill bit body, and the end of the PDC tooth refers to the end of the PDC tooth away from the cutting blade.

Specifically, when drilling in a soft stratum, the second PDC tooth 4 with a larger size can improve the scraping and rock breaking amount of the drill bit and ensure the drilling speed of the drill bit in the soft stratum; the smaller size of the first type of PDC teeth 3 maintains the invasiveness and aggressiveness of the bit when drilling into hard formations, and improves the rock breaking efficiency of the bit in hard formations.

Secondly, through the cooperation work of the first PDC teeth 3 with small size and the second PDC teeth 4 with large size, the drilling speed of the drill bit in soft stratum is considered, the rock breaking efficiency of the drill bit in hard stratum is ensured, the stratum adaptability of the drill bit is greatly improved, and particularly in soft and hard staggered stratum, the drilling adaptability of the drill bit is obviously improved.

And thirdly, through the cooperation of the first PDC teeth 3 with small size and the second PDC teeth 4 with large size, the stratum adaptability of the drill bit can be obviously improved, and compared with the conventional PDC drill bit with single tooth distribution, the rock breaking efficiency and the mechanical drilling speed of the drill bit can be improved by more than 15%, and the service life of the drill bit is prolonged by more than 20%.

Finally, the impact resistance of the first PDC teeth 3 with small size is strong, so that the impact resistance of the drill bit can be improved, and the drilling performance and the service life of the PDC drill bit in an interlayer and an inhomogeneous stratum can be enhanced through the arrangement of the first PDC teeth 3 with small size.

In an embodiment, the center line 6 of the drill bit body is taken as an axis, the first type of PDC teeth 3 are arranged on the cutting blades 2 in the area with the radius of one half of the radius of the drill bit body 1, and the total number of the first type of PDC teeth 3 is greater than or equal to the total number of the second type of PDC teeth 4 in the area.

Specifically, with the radius and the center line of the drill bit body as references, a center area of the drill bit body 1 with the center line as an axis and one half of the radius as a radius can be obtained, the first type PDC teeth 3 are arranged on the cutting blades 2 falling into the center area, and the total number of the first type PDC teeth 3 in the center area is greater than or equal to the total number of the second type PDC teeth 4.

When the drill bit drills, the drilling pressure proportion shared by the central area of the drill bit is larger, so that the drilling speed of the drill bit is reduced, in the embodiment, the central area in the radius of one half of the corresponding drill bit body 1 is set to be the total number of the first PDC teeth 3 or more and the total number of the second PDC teeth 4 or more, the drilling efficiency of the central area can be improved, and the drilling efficiency of the drill bit is further improved.

In an embodiment, in a region with the center line 6 of the bit body as an axis and one half of the radius of the bit body 1 as a radius, there is one second type of PDC teeth 4, and the distance from at least one first type of PDC teeth 3 to the center line of the bit body is equal to the distance from the second type of PDC teeth 4 to the center line 6 of the bit body.

In this embodiment, the distances between two or more PDC teeth arranged along the same track and the center line of the drill bit body are equal, so in this embodiment, there is one PDC tooth 4 of the second type, and at least one PDC tooth 4 of the second type has at least one PDC tooth 3 of the first type arranged along the same track. As shown in fig. 2, for a co-rail arrangement can be understood as: during drilling of the drill bit, the cutting contour lines 5 generated by the first type PDC teeth 3 and the cutting contour lines 5 generated by the second type PDC teeth 4 coincide, wherein the cutting contour lines 5 refer to radial contour lines formed by tooth tops of main cutting teeth on the drill bit.

When specifically arranged, more than one second type PDC tooth 4 can be arranged, and each second type PDC tooth in the second type PDC teeth is correspondingly provided with at least one first type PDC tooth 3, so that the following conditions are satisfied: the distance from the first type PDC teeth 3 to the center line of the drill bit body is equal to the distance from the second type PDC teeth 4 to the center line 6 of the drill bit body.

Thirdly, the small-size first-type PDC teeth 3 are strong in stratum invasion capability, and the large-size second-type PDC teeth 4 are strong in rock scraping and breaking capability, so that the first-type PDC teeth 3 arranged in the same track invade and presrapture (presplitting) the stratum, the strength of the stratum is reduced, and the large-size second-type PDC teeth 4 invade and scratch the stratum after presplitting; the impact and rock breaking load of the second PDC teeth 4 are weakened through the matching of the first PDC teeth 3 with small size and the second PDC teeth 4 with large size, which are arranged on the same rail; at the same time, the large-size second type PDC teeth 4 ensure a large rock scraping and breaking amount.

In one embodiment, for a first type of PDC tooth 3 and a second type of PDC tooth 4 that are equidistant, the rake angle of the first type of PDC tooth 3 is less than the rake angle of the second type of PDC tooth 4.

In this embodiment, the first type PDC teeth 3 and the second type PDC teeth 4 are further limited to be arranged on the same track, and the rake angle of the first type PDC teeth 3 is smaller than the rake angle of the second type PDC teeth 4. The rake angle refers to the angle between the cutting face of a PDC tooth and the normal 7 to the cutting profile of that PDC tooth. The bit cutting contour is a radial contour formed by the tooth tips of the main cutting teeth on the bit, and the rake angle is, for example, the angle α of fig. 3 as shown in fig. 3.

Thirdly, the small-size first-class PDC teeth 3 have small rake angles, so that the stratum invasion capability and the drill bit aggressiveness of the PDC teeth can be further improved; and the pretilt angle of the small-size first-class PDC teeth 3 is smaller than that of the large-size second-class PDC teeth 4, so that the service lives of the two types of teeth are balanced, and therefore, the advantages of each cutting tooth are fully exerted and the service lives of the two types of teeth are basically consistent.

Finally, for the first type PDC teeth 3 and the second type PDC teeth 4 which are arranged on the same rail, the first type PDC teeth 3 with small size are easy to invade stratum, so that the PDC teeth are pricked into stratum rock, thereby improving the working stability of the drill bit, prolonging the service life of the drill bit, ensuring stable scraping work of the drill bit, ensuring that the tool face of the drill bit is easier to control and ensuring that the guiding capability of the drill bit is better.

In an embodiment, as shown in fig. 4, at least one cutting blade 2 is simultaneously provided with a first type of PDC teeth 3 and a second type of PDC teeth 4, and at least a portion of the first type of PDC teeth 3 and the second type of PDC teeth 4 are alternately arranged on the cutting blade 2, and the total number of PDC teeth arranged alternately is more than half of the total number of PDC teeth on the cutting blade 2.

Specifically, for a plurality of cutting blades 2, there is at least one cutting blade 2, and the cutting blade 2 is provided with first type PDC teeth 3 and second type PDC teeth 4 simultaneously, and at least some of the first type PDC teeth 3 and second type PDC teeth 4 are alternately arranged, and the total number of the first type PDC teeth 3 and the second type PDC teeth 4 which are alternately arranged is greater than the total number of the PDC teeth on the cutting blade 2.

Wherein, the alternate arrangement means that the first type PDC teeth 3 and the second type PDC teeth 4 are formed according to the following steps: … the first type PDC teeth 3 … the second type PDC teeth 4 … the first type PDC teeth 3 … the second type PDC teeth 4 … the first type PDC teeth 3 … the second type PDC teeth 4 … are sequentially arranged, namely, for the first type PDC teeth 3 and the second type PDC teeth 4 which are alternately arranged, one second type PDC tooth 4 is arranged on the right side or the left side of each first type PDC tooth 3, or one first type PDC tooth 3 is arranged on the right side or the left side of each second type PDC tooth 4; it is also possible to take, for example: every two or three PDC teeth 3 are arranged alternately, namely, every two or three PDC teeth 4 of the second type are arranged alternately at the right side or the left side of the PDC teeth.

In an embodiment, as shown in fig. 5, at least one cutting blade 2 is provided with only the first type PDC teeth 3, and at least one cutting blade 2 is provided with only the second type PDC teeth 4, and for PDC teeth in a plane perpendicular to the center line of the bit body, the distance from the tip of the second type PDC teeth 4 of a large size to the center line of the bit body is greater than the distance from the tip of the first type PDC teeth 3 of a small size to the center line of the bit body, and the tip of the PDC teeth refers to the end of the PDC teeth away from the cutting blade.

In an embodiment, the structure further comprises at least one type of PDC tooth, wherein the size of any one PDC tooth is not equal to the size of the first type of PDC tooth 3 and the size of the second type of PDC tooth 4, and the size of the PDC tooth is more than one size.

In this embodiment, the structure further includes a type of PDC teeth, and the size of each PDC tooth in the type of PDC teeth is not equal to the size of the first type of PDC teeth 3 and the size of the second type of PDC teeth 4, so that the PDC teeth have at least three sizes on the basis of this embodiment. For ease of machining, such PDC teeth may have one, two, or three sizes, so that the overall size of the PDC teeth is three, four, or five.

In an embodiment, the cutting blades 2 include a plurality of long cutting blades 21 uniformly distributed in the circumferential direction of the drill body 1, a short cutting blade 22 is disposed between two adjacent long cutting blades 21, the minimum distance from each long cutting blade 21 to the center line of the drill body is equal, the minimum distance from each short cutting blade 22 to the center line of the drill body is equal, and the minimum distance from the long cutting blade 21 to the center line of the drill body is smaller than the minimum distance from the short cutting blade 22 to the center line of the drill body.

In an embodiment, each cutting blade 2 includes a first cutting blade section and a second cutting blade section, the first cutting blade sections are uniformly distributed in the circumferential direction of the drill bit body 1, the second cutting blade section is connected to one end of the first cutting blade section extending into the stratum, and PDC teeth are provided on the second cutting blade section.

After the PDC drill bit is connected with a drill string and is put into a well together, the stratum is cut under the action of the bit pressure, particularly when deep complex rock strata such as stratum with frequent and frequent interleaving of softness and hardness, soft (or hard) interlayer, heterogeneous stratum and the like are formed, the PDC teeth with different sizes are arranged on the cutting blades 2 of the drill bit body 1, so that the purposes of effectively improving the capability of the drill bit for invading the stratum and scraping rock breaking amount are achieved, and compared with the conventional PDC drill bit with single tooth distribution, the rock breaking efficiency and the mechanical drilling speed of the drill bit can be improved by more than 15%, the service life of the drill bit is prolonged by more than 20%, and technical support is provided for drilling and accelerating the deep complex rock stratum.

It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

Furthermore, the terms "a," "an," "the" and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. In the description of the present utility model, the meaning of "plurality" is two or more unless specifically defined otherwise.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model, and are intended to be included within the scope of the appended claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present utility model is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (7)

1. The PDC drill bit comprises a drill bit body and a plurality of cutting blades, and is characterized in that each cutting blade is provided with a plurality of PDC teeth, all the PDC teeth comprise first PDC teeth with the same size and second PDC teeth with the same size, and the size of the first PDC teeth is smaller than that of the second PDC teeth; the center line of the drill bit body is taken as an axis, the first type PDC teeth are arranged on the cutting blades in the area with the radius being half of the radius of the drill bit body, one second type PDC tooth is arranged in the area, the distance from the first type PDC tooth to the center line of the drill bit body is equal to the distance from the second type PDC tooth to the center line of the drill bit body, and for the first type PDC tooth and the second type PDC tooth with equal distances, the rake angle of the first type PDC tooth is smaller than the rake angle of the second type PDC tooth.

2. The PDC bit of claim 1 wherein the total number of PDC teeth of the first type is greater than or equal to the total number of PDC teeth of the second type within the region.

3. The PDC bit of claim 1 wherein at least one of the cutting blades is simultaneously provided with both the first type of PDC teeth and the second type of PDC teeth, wherein at least a portion of the first type of PDC teeth and the second type of PDC teeth are spaced apart from each other, and wherein the total number of PDC teeth spaced apart is greater than half the total number of PDC teeth on the cutting blade.

4. The PDC bit of claim 1 wherein at least one of the cutting blades has only the first type of PDC teeth disposed thereon and at least one of the cutting blades has only the second type of PDC teeth disposed thereon.

5. The PDC bit of claim 1 further comprising at least one type of PDC tooth, wherein the size of any one of the type of PDC tooth is not equal to the size of the first type of PDC tooth and the size of the second type of PDC tooth, the type of PDC tooth having more than one size.

6. The PDC bit of any of claims 1-5 wherein the cutting blades comprise a plurality of long cutting blades evenly distributed about a circumference of the bit body, a short cutting blade is disposed between two adjacent long cutting blades, a minimum distance from each long cutting blade to a centerline of the bit body is equal, a minimum distance from each short cutting blade to a centerline of the bit body is equal, and a minimum distance from the long cutting blade to a centerline of the bit body is less than a minimum distance from the short cutting blade to a centerline of the bit body.

7. The PDC bit of claim 6 wherein each of the cutting blades comprises a cutting blade first section and a cutting blade second section, the plurality of cutting blade first sections being evenly distributed in a circumferential direction of the bit body, the cutting blade second section being connected to an end of the cutting blade first section extending into the formation, the PDC teeth being disposed on the cutting blade second section.