CN117432340B - PDC drill bit with high specific pressure - Google Patents

PDC drill bit with high specific pressure Download PDF

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Publication number
CN117432340B
CN117432340B CN202311768119.9A CN202311768119A CN117432340B CN 117432340 B CN117432340 B CN 117432340B CN 202311768119 A CN202311768119 A CN 202311768119A CN 117432340 B CN117432340 B CN 117432340B
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China
Prior art keywords
blade
cutting blade
drill bit
main cutting
cutting
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CN202311768119.9A
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Chinese (zh)
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CN117432340A (en
Inventor
况雨春
张涛
杨博
杨淇灵
陈心玥
秦超
韩一维
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Chengdu Yanshi Innovation Technology Co ltd
Southwest Petroleum University
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Chengdu Yanshi Innovation Technology Co ltd
Southwest Petroleum University
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Priority to CN202311768119.9A priority Critical patent/CN117432340B/en
Publication of CN117432340A publication Critical patent/CN117432340A/en
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Classifications

    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/46—Drill bits characterised by wear resisting parts, e.g. diamond inserts
    • E21B10/54—Drill bits characterised by wear resisting parts, e.g. diamond inserts the bit being of the rotary drag type, e.g. fork-type bits
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH DRILLING; MINING
    • E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B10/00—Drill bits
    • E21B10/42—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits
    • E21B10/43—Rotary drag type drill bits with teeth, blades or like cutting elements, e.g. fork-type bits, fish tail bits characterised by the arrangement of teeth or other cutting elements
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/10—Greenhouse gas [GHG] capture, material saving, heat recovery or other energy efficient measures, e.g. motor control, characterised by manufacturing processes, e.g. for rolling metal or metal working

Abstract

The invention relates to a high specific pressure PDC drill bit, which belongs to the technical field of drilling equipment and comprises a connector and a drill bit body, wherein the connector is fixedly connected with one end of the drill bit body, at least two groups of high specific pressure blade groups are distributed at the other end of the drill bit body along the circumferential direction, each high specific pressure blade group comprises a main cutting blade and at least one co-rail cutting blade, and the deviation Pv of the radial positions of co-rail cutting teeth arranged on the co-rail cutting blades and the radial positions of main cutting teeth arranged on the main cutting blades of the same group ranges from-0.5 r to 0.5r, wherein r is the radius of the main cutting teeth. According to the invention, the cutting teeth on the main cutting blade bear the work of cutting rock, so that the specific pressure on a single tooth is enhanced, and the aggressiveness of the drill bit is enhanced. Meanwhile, the co-track cutting blade bears auxiliary works such as contact point increase, pre-crushing, auxiliary rock breaking and the like, so that the stability, impact resistance and wear resistance of the drill bit are improved. Thus, the high specific pressure PDC drill bit has strong aggressiveness and high stability.

Description

PDC drill bit with high specific pressure
Technical Field
The invention relates to a high specific pressure PDC drill bit, and belongs to the technical field of drilling equipment.
Background
PDC bits are also known as fixed-blade bits because the primary cutting structure of the bit is a blade structure that is relatively fixed to the bit. There are various ways to fix the blades, and the most used is a blade integrated with the bit body. However, regardless of the variation in the form of the fixation, the primary cutting elements of the PDC bit remain the PDC cutters mounted and welded to the blade apertures. When the bit pressure acts on the drill bit, the drill bit body transmits the bit pressure to the PDC cutting teeth, and the PDC cutting teeth are pressed into the rock together and do circular motion along with the drill bit around the drill bit in a revolving way, so that the rock is scraped. Therefore, under the same weight, the weight ratio on a single tooth is increased, so that the greater the depth of the cutting tooth pressed into the rock, the drill bit has stronger rock penetration capability from the aspect of phenomenon.
In the prior art, the bit penetration capacity is different for different blade numbers. Therefore, a designer usually designs a drill bit into different numbers of blades according to stratum lithology, and in terms of design principle, when the number of blades exceeds four blades, the conventional technology is provided with long blades and short blades at the same time. The main function of the short blades is to increase the tooth density of the nose and shoulder of the drill bit, thereby increasing the wear resistance of the drill bit. Meanwhile, the more the number of blades is, the more the contact points between the drill bit and the bottom of the rock shaft are, namely, the more the supporting points are, the balance of the drill bit is easier to maintain. Thus, in conventional designs, three-bit bits are typically designed for shallow layers, and seven-bit or eight-bit bits are typically designed for deep abrasive formations. The design aims at choosing the advantages and disadvantages of different numbers of blades, taking the aggression of three blades and the stability and wear resistance of eight blades. However, with the high aggressivity of the three-blade drill, the problems of unstable tool face, low borehole quality, short service life of the drill and the like during drilling of the three-blade drill are plagued by constructors. Also, eight-winged drill bits exhibit very strong wear resistance and stability when drilling into complex difficult formations, but also exhibit low specific pressure, slow rate of drilling, and long duration of drilling.
The essence of the above problem is the design method of the drill bit. The cutting teeth on all blades of a conventional drill bit participate in the bottom hole full coverage design, resulting in each blade carrying cutting work and weight on bit being distributed to all the cutting teeth on each blade. Under the condition of the same weight on bit, the more blades involved in cutting, the greater the tooth distribution density, the more cutting teeth for breaking rock, the higher the stability, the smaller the weight on bit separated from a single cutting tooth, and the smaller the aggressiveness; conversely, the fewer blades involved in cutting, the less the tooth density, the fewer cutting teeth to break the rock, the lower the stability, the higher the weight on bit on a single cutting tooth, and the greater the aggressiveness. Thus, in conventional drill bits, how to provide both high aggressiveness and high stability is a highly desirable problem.
Disclosure of Invention
Aiming at the problem that the conventional drill bit in the prior art is difficult to have high aggressivity and high stability at the same time, the invention provides the high specific pressure PDC drill bit.
The technical scheme for solving the technical problems is as follows: the utility model provides a high specific pressure PDC drill bit, includes connects and the bit body, connect the one end fixed connection of bit body, the other end of bit body distributes two at least groups of high specific pressure blade group along the circumferencial direction, high specific pressure blade group includes a main cutting blade and at least one same-track cutting blade, and the same-track cutting tooth radial position who installs on the same-track cutting blade is with the main cutting tooth radial position deviation Pv who installs on the main cutting blade of same group is-0.5 r to 0.5r, and wherein r is the radius of main cutting tooth, and the scope of same-track offset area is-0.5 r-0.5r promptly.
The definition of the on-track cutting blades and the on-track cutting teeth in the high specific pressure blade set is described herein. In a top view of the drill bit, the drill bit rotates around the central axis of the drill bit, the circle center of a main cutting tooth on a main cutting blade is taken as a base point, a circle formed by rotating the drill bit for one circle is taken as a reference circular ring, the reference circular ring is biased to a radial inward position to be negative, and the maximum value is minus 0.5r, namely the common-rail deviation value Pv is minus and the maximum value is minus 0.5r; the reference ring is biased to a radial outward position to be a positive value, and the maximum value is 0.5r, namely the common-track deviation value Pv is positive and the maximum value is 0.5r. Whereby the range of Pv forms the co-rail offset band of the primary cutting tooth. If the circle centers of the cutting teeth on the same-track cutting blade rotate a certain angle, the formed track circular arc is in the range of the same-track offset belt, and the track circular arc can be regarded as the same-track cutting teeth of the main cutting teeth of the same-track offset belt. At least one cutting tooth on the same-track cutting blade is in the range of the same-track offset band of the cutting tooth on the main cutting blade, namely at least one same-track cutting tooth on the same-track cutting blade, so that the same-track cutting blade and the main cutting blade can be called as a high-specific pressure blade group with the same group.
Based on the technical scheme, the invention can also be improved as follows:
the number of main cutting teeth mounted on the main cutting blade is as followsAnd is also provided withWhere N represents the number of main cutting blades,n i the number of the main cutting teeth on the i-th main cutting blade is R, the radius of the main cutting teeth is R, and the radius of the drill bit is R. This arrangement can provide full coverage of the well bottom while also ensuring that each main cutting blade has sufficient strength.
Further, in the high specific pressure blade group, the co-track cutting blades are arranged in the clockwise or counterclockwise direction along the circumference of the main cutting blade.
Further, the tooth distribution envelope curves of the main cutting blade and the co-track cutting blade are overlapped or offset, and the offset distance d meets the following conditions: d is more than or equal to 0.2r and less than or equal to 0.2 r.
Further, the cutting teeth on the co-orbital cutting blade are disposed at a radially outer portion of the drill bit.
Further, the radial tooth arrangement initial position of the co-track cutting blade is in the range of 0.25R-0.8R, and R is the radius of the drill bit.
Further, the main cutting teeth on the main cutting blade are wide-edge teeth.
Further, the co-track cutting teeth on the co-track cutting blade are non-planar teeth.
Further, double rows or multiple rows of cutting teeth are arranged on the main cutting blade, and/or double rows or multiple rows of cutting teeth are arranged on the co-track cutting blade.
Further, the number of blades of different high specific pressure blade sets on the same drill bit is different.
Compared with the prior art, the invention has the beneficial effects that:
1) According to the drill bit, the high specific pressure blade set is arranged, the main cutting blades and the same-rail cutting blades are matched, and the specific pressure of the main cutting teeth is increased by arranging a small number of main cutting blades, so that the aggressiveness of the drill bit is improved; through setting up same rail cutting blade, increase the contact position of drill bit and rock, prevent the drill bit unstability, increase the stability of drill bit, on the other hand, same rail cutting blade is to whole drill bit, increased the blade quantity of drill bit to increased the contact point quantity of drill bit and shaft bottom, further ensured that the drill bit keeps higher stability in drilling process, and same rail cutting tooth on the same rail cutting blade can not consume the specific pressure of main cutting tooth on the same group of main cutting blade, consequently the aggressiveness of drill bit can not reduce because of having increased same rail cutting blade. Instead, the existence of the on-track cutting teeth means that the PDC content of the whole drill bit is higher than that of the drill bit without the on-track cutting teeth, more PDC materials are required to be worn out by rock strata to enable the drill bit to fail, and the phenomenon reflected in engineering is that the service life of the drill bit is obviously prolonged.
2) The common-rail cutting teeth arranged on the common-rail cutting blades and the corresponding main cutting teeth arranged on the main cutting blades of the same group are arranged within the common-rail deviation value Pv range of-0.5 r to 0.5r, so that the auxiliary cutting function of the common-rail cutting teeth can be limited, the whole drill bit has aggressiveness and stability, and the engineering requirements of different strata can be met by adjusting reasonable deviation distances within the deviation range.
3) The radial tooth distribution starting position of the same-track cutting blade is set within the range of 0.25R-0.8R, and the cutting teeth on the same-track cutting blade are arranged at the radial peripheral part of the drill bit, so that the same-track cutting blade can bear more abrasion loss, the abrasion resistance of the drill bit is enhanced, the service life is prolonged, the contact points of the radial periphery of the drill bit are increased, the polygonal effect in the drilling process is effectively reduced, the stability of the drill bit is improved, and meanwhile, the aggressiveness is strong.
4) By setting the tooth distribution envelopes of the main cutting blade and the co-orbital cutting blade to coincide or offset distance within the range of-0.2 r to 0.2r, the degree of wear of the co-orbital cutting tooth or the main cutting tooth can be reduced while ensuring aggressiveness and stability of the drill bit.
Drawings
FIG. 1 is a schematic illustration of a high specific pressure PDC bit of the present invention;
FIG. 2 is a schematic top view of a high specific pressure PDC bit of the present invention;
FIG. 3 is a schematic view of radial tooth placement of a high specific pressure PDC drill bit of the present invention;
FIG. 4 is a seventh schematic illustration of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 5 is an eighth schematic illustration of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 6 is a schematic illustration of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 7 is a schematic illustration of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 8 is a schematic diagram of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 9 is a thirteenth schematic representation of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 10 is a fourteen schematic views of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 11 is a fifteen schematic views of an embodiment of a high specific pressure PDC bit of the present invention;
FIG. 12 is a sixteen schematic views of an embodiment of a high specific pressure PDC bit of the present invention;
in the figure, 1, a joint; 2. a bit body; 3. a high specific pressure blade set; 4. a central axis of the drill bit; 31. a main cutting blade; 32. co-rail cutting blades; 311. a main cutting tooth; 321. co-rail cutting teeth; 312. a reference arc; 322. circular track of the co-track cutting teeth; 323. a common rail bias belt; 314. radial tooth distribution envelope curves of the main cutting blades; 324. radial tooth distribution envelope curves of the same-rail cutting blades; 315. tooth crown lines of the main cutting blade; 325. tooth crown lines of the same-track cutting blades; 316. a first backup tooth; 326. a second backup tooth; pv is the common rail offset value; r is the radius of the drill bit; r is the radius of the main cutting tooth; d is the offset distance between the radial tooth distribution envelope curve of the co-rail cutting blade and the radial tooth distribution envelope curve of the main cutting blade; inp is the radial tooth arrangement starting position of the co-rail cutting blade; a is the internal taper angle of the crown of the bit body.
Detailed Description
In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit or scope of the invention, which is therefore not limited to the specific embodiments disclosed below.
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 invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.
As shown in fig. 1, a high specific pressure PDC drill bit includes a connector 1 and a drill bit body 2, wherein the connector 1 is fixedly welded with one end of the drill bit body 2, at least two high specific pressure blade sets 3 are circumferentially distributed at the other end of the drill bit body 2, i.e. the top of the drill bit, and the high specific pressure blade sets 3 are composed of a main cutting blade 31 and at least one co-rail cutting blade 32. The main cutting blade 31 mainly bears rock breaking work, a plurality of main cutting teeth 311 are distributed on the main cutting blade 31, the co-track cutting blade 32 mainly bears auxiliary work, and at least one co-track cutting tooth 321 is distributed on the co-track cutting blade 32. By providing a smaller number of main cutting blades 31, the specific pressure of the main cutting teeth 311 is increased, so that the rock penetration performance of the main cutting teeth 311 is enhanced, and the aggressiveness of the drill bit is improved. By providing the co-rail cutting blades 32, the contact area of the drill bit and rock is increased, the drill bit is prevented from being unstable, and the stability of the drill bit is increased. Meanwhile, the arrangement of the co-rail cutting teeth 321 increases the number of PDC cutting teeth of the whole drill bit, namely, the PDC material content of the drill bit is increased, and the wear resistance of the drill bit can be greatly improved. The main cutting blade 31 and the common rail cutting blade 32 form the high specific pressure blade group 3, so that the advantages of high aggression and high stability can be greatly exerted.
The radius of the main cutting tooth 311 and the radius of the on-track cutting tooth 321 may be set to be uniform or non-uniform. When the radius of the on-track cutting teeth 321 is larger than that of the main cutting teeth 311, the diamond equivalent of the cutting teeth on the on-track cutting blades 32 is increased under the condition that the number of the cutting teeth is unchanged, so that the wear resistance of the drill bit is improved; when the radius of the on-track cutting tooth 321 is smaller than that of the main cutting tooth 311, the contact length of the cutting tooth on the on-track cutting blade 32 with the rock is reduced, the specific pressure born by the on-track cutting blade 32 is reduced, so that the specific pressure of the main cutting blade 31 is increased, and the aggressiveness of the drill bit is enhanced. When the two are equal, the drill bit has wear resistance and aggressiveness, but the same radius of the same-track cutting teeth 321 and the main cutting teeth 311 just coincide with the annular shape of the rock groove formed by cutting the rock, so that the stability of the drill bit is improved.
As shown in fig. 1 and fig. 2, the drill rotates around the central axis 4 of the drill, the circle center of the main cutting teeth 311 on the main cutting blade 31 is taken as a base point, a circular track of the main cutting teeth 311 is formed along with the rotation of the drill for one circle, and a section of circular track is shown in fig. 1 and fig. 2 and is defined as a reference circular arc 312; the circle center of the co-track cutting teeth 321 on the co-track cutting blade 32 is taken as a base point, and the circle locus 322 of the co-track cutting teeth is formed along with the rotation of the drill bit. The radial distance between the reference circular arc 312 and the circular track 322 of the co-track cutting tooth matched with the reference circular arc is the co-track deviation value Pv.
The circular track 322 of the co-track cutting tooth is biased to a radial inward position relative to the reference circular arc 312 to be negative, and is defined as that the co-track deviation value Pv is negative, and the maximum value is-0.5 r, and r is the radius of the main cutting tooth 311; the circular track 322 of the co-orbital cutting tooth is offset to a positive value radially outward of the reference circular arc 312, and is defined as having a co-orbital deviation Pv of positive value, up to 0.5r. Thereby forming the common rail offset band 323 of the main cutting tooth 311. It should be noted that when there are multiple on-track cutting blades 32 in a set of high specific pressure blades 3, one main cutting tooth 311 may have on-track cutting teeth 321 matching with each of the multiple on-track cutting blades 32. The on-track deviation value Pv of the on-track cutting tooth 321 that matches the main cutting tooth 311 may be 0, at which time both are completely on-track, but the on-track cutting tooth 321 in the range of-0.5 r to 0.5r may match the main cutting tooth 311. If the circle center of the cutting tooth on the on-track cutting blade 32 rotates by a certain angle, the formed track arc is within the range of the on-track offset band 323, it can be considered as the on-track cutting tooth 321 of the main cutting tooth 311 to which the on-track offset band 323 belongs. That is, the on-track cutting blade 32 has at least one on-track cutting tooth 321. The common-rail cutting teeth 321 mounted on the common-rail cutting blades 32 and the corresponding main cutting teeth 311 mounted on the main cutting blades 31 of the same group have common-rail deviation values Pv ranging from-0.5 r to 0.5r, and the common-rail deviation values Pv range is a limit for the auxiliary cutting function of the common-rail cutting teeth 321. The sign of the on-track deviation value Pv only indicates the direction of the radially inward deviation and the radially outward deviation, and the larger the absolute value of the deviation is, the stronger the auxiliary cutting function of the on-track cutting tooth 321 is, and the more the specific pressure is shared. But relatively, it corresponds to a decrease in the specific pressure on the main cutting tooth 311, resulting in a decrease in the specific pressure of the main cutting blade 31, a decrease in aggressiveness of the entire bit, and an increase in stability. The smaller the absolute value of the deviation, the smaller the specific pressure shared by the co-orbital cutting teeth 321, the larger the specific pressure of the main cutting teeth 311, the higher the aggressiveness of the whole drill bit, and the lower the stability. When the deviation value is equal to 0, the co-track cutting teeth 321 do not have an auxiliary cutting function, and only play a role in enhancing stability and wear resistance, and at the moment, the aggressiveness of the drill bit is strongest. Therefore, the reasonable deviation distance in the deviation range can be set to adapt to engineering requirements of different strata. When the on-track deviation value Pv of the on-track cutting tooth 321 is greater than 0.5r or less than-0.5 r, the on-track cutting tooth 321 is offset radially inwards or outwards by a distance exceeding 0.5r relative to the main cutting tooth 311 matched with the on-track cutting tooth 321, the contact arc length of the on-track cutting tooth 321 and rock is increased, a larger cutting amount is born, the on-track cutting effect is weakened, the on-track cutting effect is converted into the main cutting effect, the balance design of the original main cutting cloth tooth is possibly broken, and the stability of the drill bit is reduced, so that the drill bit is failed early.
The coverage of the cutter is typically designed to combine cutters on all blades to form a well bottom completionCovering, each blade bears the function of main cutting. However, the arrangement mode can lead to larger tooth distribution density of the drill bit, the specific pressure on single teeth is reduced, and the aggressiveness of the drill bit is reduced. Conventional approaches increase the weight on bit of a single blade by reducing the blades, but this arrangement exacerbates the polygonal effect of the bit, reduces the stability of the bit, and increases the impact load to which the bit is subjected. The design of the high specific pressure blade set 3 is adopted, the blades are divided into the main cutting blade 31 and the common rail cutting blade 32, on one hand, only the main cutting teeth 311 on the main cutting blade 31 are covered at the bottom of the well, and from the view of the cutting teeth bearing the cutting function, the tooth distribution density is reduced, the specific pressure of the cutting teeth is improved, and the aggressivity of the drill bit is enhanced; on the other hand, since the on-track cutting teeth 321 on the on-track cutting blades 32 hardly perform the cutting function, the diamond content of the drill bit and the contact point between the drill bit and rock can be increased, thereby weakening the polygonal effect of the drill bit and enhancing the stability of the drill bit. In particular, the cutters mounted on the main cutting blades 31 are capable of forming full coverage downhole, i.e. satisfactory Wherein N represents the number of blades,n i for the number of cutting teeth on the i-th main cutting blade 31, R is the radius of the main cutting tooth 311, R is the radius of the drill bit, and the sum of the radii of all the main cutting teeth 311 is at least equal to or greater than the radius of the drill bit, so that the rock at each position at the bottom of the well can be crushed by the cutting teeth. Meanwhile, in order to ensure that each main cutting blade 31 has a sufficient strength, the total number range of the main cutting teeth 311 is set toThat is, the cutting teeth on the same blade cannot be close too closely, otherwise interference occurs, or the bit body material between two teeth is too little, so that the strength is insufficient, and the situation of tooth falling easily occurs during working.
As shown in fig. 3, a radial tooth profile of the present invention is shown, the radial tooth profile envelope 324 of the co-track cutting blade coincides with or is offset from the radial tooth profile envelope 314 of the main cutting blade, and the offset distance d is as follows: d is more than or equal to 0.2r and less than or equal to 0.2r. When the offset distance is equal to-0.2 r, the co-orbital cutting teeth 321 on the co-orbital cutting blade 32 first bite into the rock, pre-break the bottom of the well, and the drill bit is most aggressive. When the offset distance d is equal to 0, the radial tooth distribution envelope line 324 of the co-track cutting blade coincides with the radial tooth distribution envelope line 314 of the main cutting blade, and at this time, the main cutting tooth 311 and the co-track cutting tooth 321 simultaneously contact the bottom of the well, so that the stability of the drill bit is strongest. With increasing offset distance d, the maximum is 0.2r, which means that the main cutting tooth 311 contacts the rock after eating the rock by 0.2r, and the specific pressure is mainly borne by the main cutting tooth 311, so that the drill bit is more aggressive. The radial tooth placement starting position Inp of the on-track cutting blade 32 is in the range of 0.25R-0.8R, as seen from the tooth placement crown line 315 of the main cutting blade and the tooth placement crown line 325 of the on-track cutting blade. It can be seen that the cutting teeth on the co-orbital cutting blade 32 are disposed at the radially outer peripheral portion of the drill bit. This is because the radius of gyration of the radial peripheral portion is large, and the travel after one revolution of cutting is long, so that the cutting teeth are extremely easy to wear, and the arrangement of the co-orbital cutting teeth 321 on the peripheral portion can bear a large amount of wear, enhance the wear resistance of the drill bit, and prolong the life. In addition, the contact points at the radial periphery of the drill bit are increased by the arrangement, so that the polygonal effect in the drilling process is effectively reduced, and the stability of the drill bit is improved. The breaking of the core rock is mainly carried out by the main cutting teeth 311, and thus the main cutting blades 31 are long blades and the on-track cutting blades 32 are short blades in relative terms. When the radial tooth distribution initial position of the same-track cutting blade 32 is 0.25R, the same-track cutting blade 32 is longest, and the wear resistance is greatly enhanced on the basis of slightly strong stability; when the radial tooth arrangement starting position of the on-track cutting blade 32 is 0.8R, the on-track cutting blade 32 is shortest, and on the basis of weak stability, aggressiveness is greatly enhanced. The length of the co-orbital cutting blade 32 may be adjusted to balance the aggressiveness and wear resistance of the drill bit depending on formation lithology and operating conditions. When Inp is less than 0.25R, the on-track cutting blade 32 approaches the center of the drill, so that the flow passage between the on-track cutting blade 32 and the adjacent main cutting blade 31 is narrow, which is not beneficial to discharging rock debris; when Inp is greater than 0.8R, this is already the point from the standpoint of tooth layout where the outer shoulder is too far into gauge, and although in conventional designs cutting teeth may be arranged from this point to increase wear resistance, the on-track cutting blades 32 lose the function of the on-track cutting teeth 321 of the on-track auxiliary cutting, stability increase, etc. The main cutting teeth 311 from the bit cone part to the nose part and then to the shoulder part are provided with the pre-supporting matched co-track cutting teeth 321, so that the auxiliary functions of the co-track cutting teeth 321 can be achieved when the main cutting teeth 311 bear high specific pressure, and the service life of the drill bit is prolonged.
Preferably, the inner cone angle of the radial tooth distribution envelope 314 of the main cutting blades of the high specific pressure blade set 3, that is, the range of the inner cone angle a of the crown portion of the bit body is 150-180 °, and the small inner cone angle range is adopted to exert the advantage of the high specific pressure of the main cutting blades 31, so that the main cutting teeth 311 of the core portion are easier to eat into the rock, and the excessive bit pressure is distributed to the main cutting teeth 311 of the outer portion, thereby improving the specific pressure of the main cutting teeth 311 of the outer portion, and finally improving the aggressiveness of the whole bit.
Preferably, the co-rail cutting blades 32 of the high specific pressure blade group 3 are disposed in the circumferential clockwise or counterclockwise direction of the main cutting blade 31, forming a double blade group. When the on-track cutting blade 32 is disposed in the clockwise direction of the circumference of the main cutting blade 31, the main cutting blade 31 is in front of the travel direction of the on-track cutting blade 32, and the rock within the same on-track offset band 323 is first contacted with the main cutting tooth 311 on the main cutting blade 31, and the on-track cutting blade 32 mainly plays a role in improving the stability and wear resistance of the drill bit. When the on-track cutting blade 32 is disposed in the counterclockwise direction of the circumference of the main cutting blade 31, the on-track cutting blade 32 is in front of the traveling direction of the main cutting blade 31, and the rock within the same range of the on-track offset band 323 is firstly contacted with the cutting teeth on the on-track cutting blade 32, so that the impact of the rock on the main cutting blade 31 is reduced, the impact resistance of the main cutting teeth 311 is indirectly enhanced, and the aggressiveness of the drill bit is also reduced to a certain extent.
Preferably, the main cutting blades 31 of the high specific pressure blade group 3 are provided with the same-track cutting blades 32 along the clockwise or anticlockwise direction of the circumference, so as to form a three-blade group or a multi-blade group. The three-blade set or the multi-blade set has more changeable setting modes. Taking a three-blade set as an example, it includes one main cutting blade 31 and two co-rail cutting blades 32. When both co-orbital cutting blades 32 are arranged in the circumferential clockwise direction of the main cutting blade 31, the polygonal effect of the drill bit is lower, the stability is stronger, and the aggressiveness is stronger. When both co-orbital cutting blades 32 are arranged in the circumferential counter-clockwise direction of the main cutting blade 31, the polygonal effect of the drill bit is lower, the stability is stronger, the aggressiveness is weakened, and the impact resistance is enhanced. When two on-track cutting blades 32 are arranged with the main cutting blade 31 interposed therebetween, the on-track cutting blades 32 arranged in the circumferential clockwise direction of the main cutting blade 31 mainly play a role in enhancing stability and wear resistance, and the on-track cutting blades 32 arranged in the circumferential counterclockwise direction of the main cutting blade 31 mainly play a role in enhancing stability and impact resistance.
Typically, the spacing angle between blades is a direct consideration of the flow path distance between adjacent blades. In order to achieve a good co-orbital cutting effect between the co-orbital cutting blades 32 and the main cutting blades 31 in the same group and prevent repeated crushing of the co-orbital cutting teeth 321, compared with a conventional drill bit, the drill bit provided by the invention needs to consider the blade interval in the same high-specific pressure blade group 3. Assuming that there are multiple high specific pressure blade sets 3 with different numbers of blades on the same drill bit, the interval angle range of the blades in each high specific pressure blade set 3 should be recalculated, that is, the interval angles of the inner blades are different among different high specific pressure blade sets 3. When a plurality of co-rail cutting blades 32 are provided in one high specific pressure blade group 3, the angular interval between each blade in the same high specific pressure blade group 3 is in the range of 288 °/(n·n) in ）<a<540°/（N·N in ) Wherein N represents the number of high specific pressure blade sets 3, N in The number of blades in one high specific pressure blade set 3 is shown, the range is set to ensure that enough flow passage space is reserved between the blades for chip removal, and the unbalanced force of the drill bit can be optimized by adjusting the interval between the blades, so that the drill bit can run more stably. At the same time, the range does not lead to too narrow flow passage to form bit ballingAnd does not interfere with other high specific pressure blade sets 3 because the separation distance is too large. This is a difference from the design principle of the conventional arrangement, which is a 360 ° divided by the total number of bits. When a < 288 DEG/(N.N) in ) During the time, the interval between the blades in the same high specific pressure blade group 3 is too close, and possible chip removal is not timely caused to repeatedly crush, so that the same track cutting stability is affected and the abrasion of the drill bit is increased. When a is greater than 540 DEG/(N.N) in ) During the process, the blade interval in the same high specific pressure blade group 3 is too large, so that the polygonal effect of the drill bit is increased, the vibration of the drill bit is increased, the impact on the drill bit is increased, and the drill bit is possibly abnormally disabled.
It is further preferred that the number of blades of different high specific pressure blade sets 3 on the drill bit is different. For example, the drill bit has two high specific pressure blade groups 3, namely a double blade group and a triple blade group, wherein the main cutting blades 31 of the double blade group are provided with the same-track cutting blades 32 along the clockwise direction of the circumference, and the main cutting blades 31 of the triple blade group are provided with the same-track cutting blades 32 along the clockwise direction and the anticlockwise direction of the circumference. This arrangement may allow for selective balancing or increasing the stability and aggressiveness of the drill bit by adjusting the number of blades.
Preferably, the primary cutting teeth 311 on the primary cutting blade 31 are wide edge teeth. The aggressiveness of the drill bit is enhanced by utilizing the high specific pressure tooth edge of the wide-edge tooth. In addition, the flat cutting edge of the wide-edge tooth enables the cutting tooth to be in line contact with rock, the contact line is a straight line and basically coincides with the curve of the crown, and the bottom hole full coverage can be realized by using a small amount of wide-edge teeth in the same radial range of the crown, so that the specific pressure on a single tooth is further improved. In fact, cutting teeth with a wide-edge-like configuration can also increase the aggressiveness of the drill bit to some extent. Such as large obtuse angle teeth or large curvature tooth edge teeth or ridged wide edge teeth. The large obtuse angle tooth and the large curvature tooth edge cutting tooth are suitable for being arranged at the outer shoulder position of a drill bit so as to approach the curvature of the outer shoulder position of the crown curve, and therefore high specific pressure is obtained. The ridge-shaped wide-edge teeth are suitable for complex heterogeneous strata or interlayers, the impact resistance of the main cutting teeth 311 is improved by utilizing the buffer function of the ridge surface, and the aggressiveness of the drill bit is improved by utilizing the wide-edge teeth.
Preferably, the on-track cutting teeth 321 on the on-track cutting blade 32 are non-planar teeth. Different non-planar teeth are selected according to different stratum environments, for example, ridge-shaped non-planar teeth (ridge teeth and Benz teeth) are selected in heterogeneous stratum and soft and hard staggered stratum, so that the contact between the working face of the cutting teeth and rock is a continuous process, and the shock resistance of the drill bit is improved. For another example, wedge teeth or cone teeth are selected for abrasive formations to increase the diamond content of the cutting teeth and thereby increase the wear resistance of the drill bit.
Preferably, the cutting teeth on the main cutting blade 31 may be arranged in two rows or multiple rows, specifically, the first backup teeth 316 are arranged behind the main cutting teeth 311, and the first backup teeth 316 may be arranged in one row or multiple rows, which has the beneficial effect of increasing the diamond composite sheet of the main cutting blade 31, thereby increasing the diamond content and prolonging the service life of the main cutting blade 31.
Preferably, the cutting teeth on the on-track cutting blade 32 may be arranged in two or more rows, and in particular, the second backup teeth 326 are arranged in the trailing row of on-track cutting teeth 321. In this way, the contact point of the cutting teeth on the co-orbital cutting blade 32 with the rock is increased, increasing the stability of the drill bit. On this basis, the on-track cutting tooth 321 and the second backup tooth 326 may be set to different offset distances d, balancing the auxiliary cutting function and the stability maintaining function of the on-track cutting blade 32, so that the on-track cutting blade 32 has more comprehensive performance. Meanwhile, different tooth profiles of the co-track cutting teeth 321 and the second backup teeth 326 can be selected, for example, the co-track cutting teeth 321 on the co-track cutting blade 32 are selected as ridged teeth to increase the impact resistance of the co-track cutting blade 32, and the second backup teeth 326 are selected as wedge-shaped teeth to enhance the wear resistance of the co-track cutting blade 32, so that the co-track cutting blade 32 has more comprehensive performance.
Based on the above features, embodiments having particular advantageous effects will be described in connection with the following examples.
Embodiment one: as shown in FIG. 1, in one embodiment of a high specific pressure PDC bit, the radius R of the bit is 107.95mm, the radius R of the primary cutting teeth 311 is 6.72mm, and a single row of planar buttons are disposed on both the primary cutting blades 31 and the co-orbital cutting blades 32. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The beneficial effect of this scheme lies in that main cutting blade 31 is in the place ahead of the co-track cutting blade 32 advancing direction, and the rock of same co-track offset area 323 within range contacts with main cutting tooth 311 on the main cutting blade 31 at first, and co-track cutting blade 32 mainly plays the effect that improves drill bit stability and wearability.
Embodiment two: this solution differs from the first embodiment in that the radial position of the co-orbital cutting teeth 321 mounted on the co-orbital cutting blade 32 is-3.36 mm from the co-orbital deviation Pv of the main cutting teeth 311 on the main cutting blades 31 of the same group. According to the scheme, through increasing the common-rail deviation Pv, the rock breaking effect of the common-rail cutting teeth 321 is increased, the cutting effect of the main cutting teeth 311 is reduced, and the specific pressure on the main cutting teeth 311 is reduced, so that the aggressibility of the drill bit is weaker, but the drill bit is more stable and the wear resistance is stronger.
Embodiment III: this embodiment differs from the first embodiment in that the radial position of the on-track cutting teeth 321 mounted on the on-track cutting blades 32 is 3.36mm from the on-track deviation Pv of the main cutting teeth 311 on the main cutting blades 31 of the same group. According to the scheme, through increasing the common-rail deviation Pv, the rock breaking effect of the common-rail cutting teeth 321 is increased, the cutting effect of the main cutting teeth 311 is reduced, and the specific pressure on the main cutting teeth 311 is reduced, so that the aggressibility of the drill bit is weaker, but the drill bit is more stable and the wear resistance is stronger. The second embodiment and the third embodiment are two opposite same-track deviations, the unbalanced force generated by the cutter wing is opposite, and the unbalanced force of the drill bit can be reduced and the stability of the drill bit can be enhanced through adjusting the same-track deviations.
Embodiment four: this variant differs from the first embodiment in that the radial tooth placement starting position Inp of the co-rail cutting blade 32 is 64.77 mm. The scheme has shorter on-track cutting blades 32, and the aggressiveness is enhanced on the basis of unchanged stability.
Fifth embodiment: this solution differs from the first embodiment in that the radial tooth profile 314 of the main cutting blade and the radial tooth profile 324 of the co-orbital cutting blade are offset by a distance d equal to-1.344 mm. In the scheme, the co-rail cutting teeth 321 on the co-rail cutting blades 32 firstly bite into rock, pre-break is caused to the bottom of the well, and the drill bit has the strongest aggressiveness.
Example six: this solution differs from the first and third embodiments in that the radial tooth envelope 314 of the main cutting blade and the radial tooth envelope 324 of the co-orbital cutting blade are offset by a distance d equal to 1.344mm. In this scheme, the main cutting tooth 311 contacts the rock after eating the rock by 1.344mm, and the specific pressure is mainly borne by the main cutting tooth 311, so that the drill bit has stronger aggressiveness.
Embodiment seven: as shown in FIG. 4, in one embodiment of a high specific pressure PDC bit, the radius R of the bit is 107.95mm, the radius R of the primary cutting teeth 311 is 6.72mm, and a single row of planar buttons are disposed on both the primary cutting blades 31 and the co-orbital cutting blades 32. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The difference from the first embodiment is that the on-track cutting blade 32 is provided in the counterclockwise direction along the circumference of the main cutting blade 31. The radial position of the on-track cutting tooth 321 mounted on the on-track cutting blade 32 is offset from the on-track of the main cutting tooth 311 mounted on the main cutting blade 31 of the same set by 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The same-track cutting blade 32 is in front of the advancing direction of the main cutting blade 31, and the rock in the range of the same-track offset band 323 is firstly contacted with the cutting teeth on the same-track cutting blade 32, so that the impact of the rock on the main cutting blade 31 is reduced, the impact resistance of the main cutting teeth 311 is indirectly enhanced, and the aggressiveness of the drill bit is also reduced to a certain extent.
Example eight: as shown in FIG. 5, the radius R of the high specific pressure PDC drill bit is 107.95mm, the radius R of the main cutting teeth 311 is 6.72mm, and single-row plane circular teeth are arranged on the main cutting blades 31 and the co-track cutting blades 32. The difference from the first embodiment is that two groups of high specific pressure blades 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blades 3 consists of one main cutting blade 31 and two co-orbital cutting blades 32. Both co-rail cutting blades 32 are arranged in the circumferential clockwise direction of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The beneficial effect of this scheme lies in that the polygon effect of drill bit is lower, and stability is stronger, and aggressiveness is stronger.
Example nine: as shown in FIG. 6, the radius R of the high specific pressure PDC drill bit is 107.95mm, the radius R of the main cutting teeth 311 is 6.72mm, and single-row plane circular teeth are arranged on the main cutting blades 31 and the co-track cutting blades 32. The difference from the first embodiment is that two groups of high specific pressure blades 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blades 3 consists of one main cutting blade 31 and two co-orbital cutting blades 32. The difference from the eighth embodiment is that both of the on-track cutting blades 32 are arranged in the counterclockwise direction of the circumference of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The technical scheme has the advantages that the polygonal effect of the drill bit is lower, the stability is stronger, the aggressiveness is weakened, and the impact resistance is enhanced.
Example ten: as shown in FIG. 7, the radius R of the high specific pressure PDC drill bit is 107.95mm, the radius R of the main cutting teeth 311 is 6.72mm, and single-row plane circular teeth are arranged on the main cutting blades 31 and the co-track cutting blades 32. The difference from the first embodiment is that two groups of high specific pressure blades 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blades 3 consists of one main cutting blade 31 and two co-orbital cutting blades 32. The difference from the eighth and ninth embodiments is that two on-track cutting blades 32 are arranged with the main cutting blade 31 interposed therebetween, the on-track cutting blades 32 arranged in the circumferential clockwise direction of the main cutting blade 31 mainly play a role in enhancing stability and wear resistance, and the on-track cutting blades 32 arranged in the circumferential counterclockwise direction of the main cutting blade 31 mainly play a role in enhancing stability and impact resistance. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The beneficial effect of this scheme lies in that the polygon effect of drill bit is lower, and has strengthened the stability and the impact resistance of drill bit simultaneously.
Example eleven: the difference between the scheme and the eighth, ninth and tenth embodiments is that the two high specific pressure blade sets 3 distributed at the top of the scheme are a double blade set and a triple blade set, the main cutting blades 31 of the double blade set are provided with the same-rail cutting blades 32 along the clockwise direction of the circumference, and the main cutting blades 31 of the triple blade set are provided with the same-rail cutting blades 32 along the clockwise and anticlockwise directions of the circumference. The technical scheme has the beneficial effects that the aggressiveness of the high specific pressure blade group 3 is selectively improved by adjusting the number of blades in the group. For example, compared with the embodiment eight, the embodiment nine and the embodiment ten, in the high specific pressure blade group 3 with fewer blades, the bit pressure on the single blade is further increased, namely, the specific pressure is further improved, and the aggressivity of the drill bit is enhanced.
Embodiment twelve: as shown in FIG. 8, the radius R of the high specific pressure PDC drill bit is 107.95mm, and the radius R of the main cutting teeth 311 is 6.72mm. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. Planar circular teeth are arranged on the co-track cutting blades 32, and are co-track cutting teeth 321. The difference from the first embodiment is that double rows of planar buttons, namely, the primary cutting teeth 311 and the first backup teeth 316, are arranged on the primary cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The beneficial effect of this scheme lies in that the main cutting blade 31 arranges double cutting teeth, and the main cutting teeth 311 of first row mainly are used for cutting rock, and the first backup teeth 316 of second row mainly strengthen the wearability of drill bit, improve the atress condition of main cutting teeth 311 to strengthen the life-span of main cutting teeth 311.
Embodiment thirteen: a high specific pressure PDC bit as shown in FIG. 9 has a bit radius R of 107.95mm and a primary cutter 311 radius R of 6.72mm. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. The main cutting blades 31 are each provided with a planar button, i.e., main cutting teeth 311. The difference from the first embodiment is that double rows of cutting teeth, that is, the on-track cutting tooth 321 and the second backup tooth 326 are disposed on the on-track cutting blade 32. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The double-row plane circular teeth are arranged on the same-track cutting blade 32, so that the contact point of the same-track cutting blade 32 is increased, the effect of limiting the eating depth of the main cutting blade 31 is achieved, and the load fluctuation of the main cutting teeth 311 on the main cutting blade 31 is smaller; on the other hand, the stability of the drill bit is improved, and the service life of the drill bit is prolonged.
According to stratum and working condition characteristics, the cutting teeth of the high specific pressure PDC drill bit can be provided with non-planar teeth.
Fourteen examples: as shown in FIG. 10, the radius R of the high specific pressure PDC drill bit is 107.95mm, and the radius R of the main cutting teeth 311 is 6.72mm. The difference from the first embodiment is that the main cutting teeth 311 of the main cutting blade 31 of this embodiment are arranged as a single row of wide edge teeth. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The technical proposal has the advantages that the aggressiveness of the drill bit is enhanced by utilizing the high specific pressure tooth edge of the wide-edge tooth; in addition, the flat cutting edge of the wide-edge tooth enables the cutting tooth to be in line contact with rock, the contact line is a straight line and basically coincides with the curve of the crown, and the bottom hole full coverage can be realized by using a small amount of wide-edge teeth in the same radial range of the crown, so that the specific pressure on a single tooth is further improved.
Example fifteen: as shown in FIG. 11, the radius R of the high specific pressure PDC drill bit is 107.95mm, and the radius R of the main cutting teeth 311 is 6.72mm. The difference from the first embodiment is that the main cutting teeth 311 of the main cutting blade 31 of this embodiment are arranged as a single row of ridge teeth. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The technical proposal has the beneficial effects that the contact between the ridge tooth working surface and the rock is a continuous process, thereby improving the shock resistance of the drill bit.
Example sixteen: as shown in FIG. 12, the radius R of the high specific pressure PDC drill bit is 107.95mm, and the radius R of the main cutting teeth 311 is 6.72mm. The difference from the first embodiment is that the co-orbital cutting teeth 321 of the co-orbital cutting blade 32 of this embodiment are arranged as a single row of ridged teeth. Three groups of high specific pressure blade groups 3 are circumferentially distributed on the top of the drill bit, and each group of high specific pressure blade groups 3 consists of a main cutting blade 31 and a common-rail cutting blade 32. The on-track cutting blade 32 is disposed in the circumferential clockwise direction of the main cutting blade 31. The radial position deviation (co-orbital deviation Pv) of the co-orbital cutting tooth 321 mounted on the co-orbital cutting blade 32 from the radial position of the main cutting tooth 311 mounted on the main cutting blade 31 of the same group is 0. The radial tooth profile 314 of the primary cutting blade coincides with the radial tooth profile 324 of the co-orbital cutting blade. The radial tooth placement starting position Inp of the co-rail cutting blade 32 is 32.385 mm. The beneficial effect of this scheme lies in utilizing the ridge tooth working face to be in continuous process with the contact of rock to improve the shock resistance of same rail cutting blade 32, strengthen the stability of drill bit.
Comparative example one: this solution differs from the first embodiment in that the radial position of the co-orbital cutting teeth 321 mounted on the co-orbital cutting blade 32 is-4.12 mm from the co-orbital deviation Pv of the main cutting teeth 311 on the main cutting blades 31 of the same group. In this scheme, the common-rail cutting teeth 321 share more specific pressure, which results in smaller specific pressure of the main cutting blade 31, so that the aggressiveness of the drill bit is obviously lower.
Comparative example two: this embodiment differs from the first embodiment in that the radial position of the on-track cutting teeth 321 mounted on the on-track cutting blades 32 is 4.06mm from the on-track deviation Pv of the main cutting teeth 311 on the main cutting blades 31 of the same group. In this scheme, the common-rail cutting teeth 321 share more specific pressure, which results in smaller specific pressure of the main cutting blade 31, so that the aggressiveness of the drill bit is obviously lower.
Comparative example three: this variant differs from the fourth embodiment in that the radial tooth placement starting position Inp of the co-rail cutting blade 32 is at 20.52. In this solution the co-orbital cutting blade 32 is too long to deviate its aggressiveness and is not conducive to the removal of cuttings.
Comparative example four: this variant differs from the fourth embodiment in that the radial tooth placement starting position Inp of the co-rail cutting blade 32 is at 90.22. In this embodiment, the on-track cutting blade 32 is extremely short, which makes its stability deviate.
Comparative example five: this solution differs from embodiment five in that the radial tooth profile envelope 314 of the main cutting blade and the radial tooth profile envelope 324 of the co-orbital cutting blade are offset by a distance d equal to-2.016 mm. In this scheme, the on-track cutting teeth 321 on the on-track cutting blade 32 first eat rock, but the off-set distance d is too large, so that the on-track cutting teeth 321 are very easy to wear, and the service life of the on-track cutting teeth is affected.
Comparative example six: this solution differs from embodiment six in that the radial tooth profile envelope 314 of the main cutting blade and the radial tooth profile envelope 324 of the co-orbital cutting blade are offset by a distance d equal to 2.016mm. In this solution, the main cutting tooth 311 first bites into rock, but the offset distance d is too large, so that the main cutting tooth 311 is extremely easy to wear, and the service life of the main cutting tooth is affected.
Drilling tests were performed on the drill bits obtained in examples one to sixteen and comparative examples one to six, and test results of examples one to three, comparative examples one and two were recorded, so that table 1 was obtained;
recording test results of the fourth embodiment, the third comparative embodiment and the fourth embodiment to obtain table 2;
recording test results of the fifth, sixth and the fifth and sixth comparative examples, and obtaining table 3;
recording the test results of examples seven to eleven, table 4 was obtained; recording the test results of twelve to sixteen examples, table 5 can be obtained, wherein the ranking of the performances is as follows: difference < worse < generally < slightly stronger < stronger.
Table 1 evaluation tables of characteristics, dimensions and test results of examples one to three and comparative examples one and two of the present invention
As can be seen from the experimental evaluation of the first to third embodiments and the first and second comparative embodiments and in combination with the table 1, in the scheme, the common-rail cutting teeth 321 mounted on the common-rail cutting blades 32 and the corresponding common-rail deviation values Pv of the main cutting teeth 311 mounted on the main cutting blades 31 of the same group are set within the range of-0.5 r to 0.5r, and the auxiliary cutting function of the common-rail cutting teeth 321 is properly limited, so that the whole aggressivity and stability of the drill bit, the impact resistance and the wear resistance are excellent, and the engineering requirements of different strata can be met by adjusting reasonable deviation distances within the deviation range.
TABLE 2 evaluation of characteristics, dimensions and test results of example IV and comparative example III, four of the present invention
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As can be seen from experimental evaluation of the fourth embodiment, the third comparative embodiment and the fourth embodiment and in combination with table 2, the radial tooth arrangement starting position of the co-track cutting blade 32 is within the range of 0.25R-0.8R, and the cutting teeth on the co-track cutting blade 32 are arranged on the radial peripheral part of the drill bit, so that the co-track cutting blade can bear more abrasion loss, the abrasion resistance of the drill bit is enhanced, the service life is prolonged, the contact points of the radial periphery of the drill bit are increased, the polygonal effect in the drilling process is effectively reduced, the stability of the drill bit is increased, and meanwhile, the aggressiveness is strong. The length of the co-orbital cutting blade 32 may be adjusted to balance the aggressiveness and wear resistance of the drill bit depending on formation lithology and operating conditions.
TABLE 3 evaluation of characteristics, dimensions and test results of examples five to six and comparative examples five to six of the present invention
From the experimental evaluation of the fifth, sixth and the fifth and sixth embodiments, and in combination with the table 3, it can be seen that, in this embodiment, by setting the radial tooth distribution envelope 314 of the main cutting blade and the radial tooth distribution envelope 324 of the co-track cutting blade to coincide or the offset distance d to be within the range of-0.2 r.ltoreq.d.ltoreq.0.2 r, the aggressiveness and stability of the drill bit can be ensured at the same time, and in this distance range, the engineering requirements of different strata can be adapted by appropriate adjustment.
TABLE 4 evaluation of the characteristics, dimensions and test results of examples seven to eleven of the present invention
TABLE 5 evaluation of twelve to sixteen characteristics, dimensions and test results of examples of the present invention
From the seventh to sixteenth embodiments, as shown by the experimental evaluation of table 4 and table 5, when the on-track deviation value Pv, the radial tooth arrangement starting position of the on-track cutting blade 32 and the offset distance d are all set within the appropriate ranges, the on-track cutting blade 32 is set in the clockwise or counterclockwise direction along the circumference of the main cutting blade 31, or the number and the setting direction of the high specific pressure blade group 3, and the cutting tooth shapes on the blades can be adaptively adjusted according to the formation lithology and the different working conditions, and meanwhile, the drill bit can be ensured to have excellent aggressiveness and stability.
It should be noted that in some of the above embodiments, the high specific pressure blade set 3 on the same drill bit has the same blade structure form in the set, because the embodiments describe representative features, if fine adjustment is performed on the blade structure forms in different high specific pressure blade sets 3, the blade structure forms in different sets are different, and even if the use effect is not the same as the beneficial effect of the representative embodiments, the use effect still falls within the protection scope of the present invention. For example, the high specific pressure blade set 3 in the twelve-stage embodiment is changed to two sets of "main cutting blade 31+co-rail cutting blade 32" and one set of "co-rail cutting blade 32+main cutting blade 31", so that the beneficial effects of the adjusted solution are not as obvious as those of the twelve-stage embodiment, but still the protection scope of the invention.
The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.
The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims (9)

1. The utility model provides a high specific pressure PDC drill bit, includes connects and the bit body, connect the one end fixed connection of bit body, its characterized in that: the other end of the drill bit body is provided with at least two groups of high specific pressure blade groups along the circumferential direction, the high specific pressure blade groups comprise a main cutting blade and at least one co-rail cutting blade, and the deviation Pv of the radial position of co-rail cutting teeth arranged on the co-rail cutting blade and the radial position of main cutting teeth arranged on the main cutting blade of the same group ranges from-0.5 r to 0.5r, wherein r is the radius of the main cutting teeth;
the number of main cutting teeth mounted on the main cutting blade is as followsAnd->Wherein N represents the number of main cutting blades, N i On the ith main cutting blade The number of the main cutting teeth, R is the radius of the main cutting teeth, and R is the radius of the drill bit.
2. The high specific pressure PDC bit of claim 1 wherein: in the high specific pressure blade group, the co-track cutting blades are arranged on the main cutting blade along the circumference clockwise or anticlockwise direction.
3. The high specific pressure PDC bit of claim 1 wherein: the tooth distribution envelops of the main cutting blade and the co-track cutting blade are overlapped or offset, and the offset distance d meets the following conditions: d is more than or equal to 0.2r and less than or equal to 0.2r.
4. The high specific pressure PDC bit of claim 1 wherein: cutting teeth on the co-orbital cutting blade are disposed at a radially outer portion of the drill bit.
5. The high specific pressure PDC bit of claim 4 wherein: the radial tooth arrangement starting position of the co-track cutting blade is in the range of 0.25R-0.8R, and R is the radius of the drill bit.
6. The high specific pressure PDC bit of claim 1 wherein: the main cutting teeth on the main cutting blade are wide-edge teeth.
7. The high specific pressure PDC bit of claim 1 wherein: and the co-track cutting teeth on the co-track cutting blade are non-planar teeth.
8. The high specific pressure PDC bit of claim 1 wherein: and double rows or multiple rows of cutting teeth are arranged on the main cutting blade, and/or double rows or multiple rows of cutting teeth are arranged on the co-track cutting blade.
9. The high specific pressure PDC bit of claim 1 wherein: the number of blades of different high specific pressure blade sets on the same drill bit is different.
CN202311768119.9A 2023-12-21 2023-12-21 PDC drill bit with high specific pressure Active CN117432340B (en)

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