CN114592796B - PDC drill bit suitable for tight mudstone stratum - Google Patents
PDC drill bit suitable for tight mudstone stratum Download PDFInfo
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- CN114592796B CN114592796B CN202210500029.0A CN202210500029A CN114592796B CN 114592796 B CN114592796 B CN 114592796B CN 202210500029 A CN202210500029 A CN 202210500029A CN 114592796 B CN114592796 B CN 114592796B
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- cutter holder
- connecting rod
- cutting unit
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- wall
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- 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
- E21B10/26—Drill bits with leading portion, i.e. drill bits with a pilot cutter; Drill bits for enlarging the borehole, e.g. reamers
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- 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
- E21B10/60—Drill bits characterised by conduits or nozzles for drilling fluids
- E21B10/602—Drill bits characterised by conduits or nozzles for drilling fluids the bit being a rotary drag type bit with blades
Abstract
The invention belongs to the field of drilling equipment, and particularly relates to a PDC drill bit suitable for a compact mudstone stratum, which comprises an external cutting unit; an inner cutting unit; a connecting rod; the outer cutting unit can move relative to the inner cutting unit along the circumferential direction, locking and releasing between the two cutting units are achieved through the locking mechanism, when fluffy strata are cut, the inner cutting unit serves as a pilot drill bit and protrudes in front of the outer cutting unit, the outer cutting unit serves as a reaming drill bit and reams the area around the inner cutting unit, the whole drilling capacity of the drill bit is improved, a large gap is formed between the inner blade and the outer blade, and mud bags at the front end of the drill bit can be avoided; when cutting a compact mudstone stratum, the inner cutting unit and the outer cutting unit can be kept parallel and level, so that cutting stress is dispersed, the stability of a drilling process is ensured, and edge breakage is avoided. The invention can switch between two stations back and forth so as to adapt to the complex stratum environment with staggered hardness.
Description
Technical Field
The invention belongs to the field of drilling equipment, and particularly relates to a PDC drill bit suitable for a compact mudstone stratum.
Background
The PDC drill bit is also called a polycrystalline diamond composite drill bit, and generally comprises a drill bit body and a polycrystalline diamond compact embedded at the end part of the drill bit body, wherein the polycrystalline diamond compact is a cutting part which takes hard alloy as a substrate and has a polycrystalline diamond coating on the surface. The conventional PDC drill bit is generally of an integrated structure, the relative positions of cutting teeth are generally fixed, however, in the actual use process, the cutting efficiency of the drill bit is greatly influenced by the distribution conditions of the cutting teeth aiming at different geological layers, for example, in a relatively fluffy upper rock layer, the drilling speed can be obviously improved by adopting a small cutting area, and the drilling speed is reduced and mud bags are easy to appear at the end part of the drill bit by adopting a large cutting area; and for compact mud rock formations, the adoption of a larger cutting area is more beneficial to the stable feeding of the drill bit. Because the drill bit among the prior art is the integral type structure, consequently need change the drill bit repeatedly when facing different terranes, seriously influence well drilling efficiency.
Disclosure of Invention
In view of the above-mentioned drawbacks of the prior art, it is an object of the present invention to provide a PDC bit for tight mudstone formations that can improve drilling efficiency.
In order to achieve the above objects and other related objects, the present invention provides the following technical solutions:
a PDC bit adapted for use in tight mudstone formations, comprising:
the outer cutting unit comprises an outer cutter holder, a center hole penetrating through the outer cutter holder is formed in the center of the outer cutter holder, outer cutter wings are arranged on the crown of the outer cutter holder and extend to the side faces of the outer cutter holder from the edge of the center hole, and a plurality of outer cutter wings are arranged at intervals along the circumferential direction of the outer cutter holder;
the inner cutting unit comprises an inner cutter holder, inner cutter wings are arranged on the crown part of the inner cutter holder and only distributed on the end surface of the inner cutter holder, and a plurality of inner cutter wings are arranged at intervals along the circumferential direction of the inner cutter holder; the inner cutter holder is movably arranged in a central hole of the outer cutter holder along the axial direction, so that the inner cutting unit and the outer cutting unit can be switched between the following two stations: the inner blade axially protrudes for a preset distance relative to the outer blade at a first station; and a second station, wherein the inner blade is flush with the crown of the outer blade; the inner cutter holder and the outer cutter holder are synchronously and rotationally connected along the circumferential direction;
one end of the connecting rod is provided with a connecting part for connecting a drill rod, and the other end of the connecting rod is connected with the inner cutter holder so as to drive the inner cutter holder to feed along the axial direction and rotate along the circumferential direction;
the locking mechanism is arranged between the inner cutter holder and the outer cutter holder and is assembled to form a locking station and an unlocking station, and when the locking mechanism is positioned at the locking station, the outer cutting unit and the inner cutting unit positioned at the second station can be kept at the second station, so that the outer cutting unit and the inner cutting unit can be synchronously fed in the state of the second station; when the locking mechanism is located at an unlocking station, the outer cutting unit can freely move relative to the inner cutting unit along the axial direction, so that when the inner cutting unit is fed, the outer cutting unit can be switched to the first station under the blockage of rock strata and is kept at the first station;
and diamond composite cutting teeth are arranged on the outer blade and the inner blade.
In an optional embodiment of the invention, a blind hole is formed in one end of the inner tool apron, which is far away from the inner tool wing, and the connecting rod is inserted into the blind hole; the locking mechanism comprises a ball movably arranged on the side wall of the inner cutter holder and an annular groove arranged on the inner wall of the outer cutter holder, when the inner cutting unit and the outer cutting unit are positioned at the second station, the ball is aligned with the annular groove, a radial hole penetrating through the side wall is formed in the side wall of the inner cutter holder, the ball is movably arranged in the radial hole along the radial direction of the inner cutter holder, the diameter of the ball is larger than the thickness of the side wall of the inner cutter holder, a groove is formed in the position, corresponding to the ball, of the connecting rod, the bottom surface of the groove is in smooth transition with the outer wall of the connecting rod, the connecting rod is in rotating fit with the inner cutter holder within a preset angle range, so that the connecting rod and the inner cutter holder can be switched between a first angle range and a second angle range, and when the connecting rod and the inner cutter holder are positioned between the first angle range, the ball is opposite to the groove, the inner side of the ball can be partially accommodated in the groove at the moment, so that the outer side of the ball avoids the annular groove, and the locking mechanism is positioned at the unlocking station at the moment; when the connecting rod and the inner cutter holder are located in a second angle range, the grooves and the balls are mutually staggered in the circumferential direction, so that the balls are pushed into the annular groove by the connecting rod, and the locking mechanism is located at the locking station; when the connecting rod rotates along a first direction relative to the inner cutter seat, the two angle intervals are switched from a first angle interval to a second angle interval, and the first direction is the cutting direction of the drill bit.
In an optional embodiment of the present invention, a protruding tooth is disposed on an outer wall of the connecting rod, a first arc-shaped slot and a second arc-shaped slot that are matched with the protruding tooth are disposed on an inner wall of the inner tool apron, the first arc-shaped slot and the second arc-shaped slot are disposed at an interval along an axial direction of the inner tool apron and are communicated with each other through an axial slot, the connecting rod is movably connected with the inner tool apron along the axial direction, so that the protruding tooth switches between the first arc-shaped slot and the second arc-shaped slot, when the protruding tooth is located in the first arc-shaped slot, the connecting rod can move between the first angle interval and the second angle interval, and when the protruding tooth is located in the second arc-shaped slot, the connecting rod can only move within the first angle interval; when the connecting rod moves relative to the inner cutter base along a first linear direction, the convex teeth can move from the first arc-shaped groove to the second arc-shaped groove, and the first linear direction is the feeding direction of the drill bit.
In an optional embodiment of the invention, a main water channel is arranged inside the connecting rod, a first liquid dividing cavity is formed between the inner wall of the outer cutter holder and the outer wall of the connecting rod, a second liquid dividing cavity is formed between the end part of the connecting rod and the inner cutter holder, and a first through hole and a second through hole which are respectively communicated with the first liquid dividing cavity and the second liquid dividing cavity are arranged on the side wall of the connecting rod; a first flow channel is arranged in the outer cutter holder, a liquid inlet of the first flow channel is communicated with the first liquid dividing cavity, a liquid outlet of the first flow channel is formed in the crown part of the outer cutter holder, and the liquid outlet is positioned between two adjacent outer blades; the inner cutter holder is internally provided with a second flow channel, a liquid inlet of the second flow channel is communicated with the second liquid dividing cavity, a liquid outlet of the second flow channel is formed at the end part of the inner cutter holder, and the liquid outlet is positioned between two adjacent inner blades.
In an optional embodiment of the present invention, a convex ring is formed on the connecting rod, a first step portion and a second step portion are formed on the inner wall of the outer tool apron, an inner ring surface of the first step portion is attached to the outer wall of the connecting rod, an inner ring surface of the second step portion is spaced from the outer wall of the connecting rod, the first step portion and the second step portion are located on one side close to the crown portion of the outer tool apron relative to the convex ring, the inner wall of the outer tool apron, the first step portion and the second step portion jointly enclose the first liquid separation cavity, and when liquid is filled in the first liquid separation cavity, a thrust in a first linear direction can be generated on the outer tool apron.
In an optional embodiment of the present invention, the liquid inlet of the first flow channel is formed on an inner annular surface of the second step portion.
In an optional embodiment of the present invention, a closing mechanism is disposed between the connecting rod and the inner tool holder, and the closing mechanism is configured to disconnect the water path between the main water path and the second liquid dividing chamber when the connecting rod and the inner tool holder are at a first relative preset angle, the first relative preset angle is located in the first angle interval, and the water path between the main water path and the second liquid dividing chamber is communicated when the connecting rod and the inner tool holder are at other relative angles in the first angle interval and the second angle interval.
In an optional embodiment of the present invention, the closing mechanism includes an axial groove formed in an inner wall of the inner tool apron, and when the connecting rod and the inner tool apron are located at other relative angles except for the first relative preset angle in the first angle interval and the second angle interval, the second through hole is opposite to the axial groove, and at this time, the second through hole is communicated with the second liquid dividing chamber through the axial groove; when the connecting rod and the inner cutter seat are positioned at the first relative preset angle, the second through hole is staggered with the axial strip groove, and the second through hole is disconnected with the second liquid dividing cavity.
In an optional embodiment of the present invention, a bar key is formed on the inner tool apron extending from the outer end of the inner blade to the side wall of the inner tool apron, and a key slot matching with the bar key is formed on the inner wall of the outer tool apron.
In an alternative embodiment of the present invention, the number of the outer blades is greater than the number of the inner blades, and each of the inner blades has one outer blade aligned in the radial direction with the outer blade, and the inner ends of the outer blades aligned with the inner blades are provided with auxiliary liquid injection ports, the auxiliary liquid injection ports are arranged toward the outer wall of the bar-shaped key, and the auxiliary liquid injection ports are communicated with the first flow channel.
The invention has the technical effects that: the combined drill bit with the movable part is adopted, wherein the outer cutting unit can move relative to the inner cutting unit along the circumferential direction, and locking and releasing between the two cutting units are realized through the locking mechanism; when cutting a compact mudstone stratum, the inner cutting unit and the outer cutting unit can be kept parallel and level, so that cutting stress is dispersed, the stability of a drilling process is ensured, and edge breakage is avoided. The invention can switch between two stations back and forth so as to adapt to the complex stratum environment with staggered hardness.
Drawings
FIG. 1 is a perspective view of a PDC bit provided in accordance with an embodiment of the present invention at station one;
FIG. 2 is a front view of a PDC bit at station one provided by an embodiment of the present invention;
FIG. 3 is an end view of a PDC bit provided by embodiments of the present invention;
FIG. 4 is a cross-sectional view A-A of FIG. 3;
FIG. 5 is a cross-sectional view B1-B1 of FIG. 4;
FIG. 6 is a cross-sectional view of C1-C1 of FIG. 4;
FIG. 7 is a cross-sectional view D1-D1 of FIG. 4;
FIG. 8 is a cross-sectional view of E1-E1 of FIG. 4;
FIG. 9 is a cross-sectional view of an intermediate condition of a PDC bit having a cutaway position consistent with FIG. 5 in accordance with an embodiment of the present invention;
FIG. 10 is a cross-sectional view of an intermediate condition of a PDC bit provided in accordance with an embodiment of the present invention, the cut-away position being consistent with FIG. 6;
FIG. 11 is a cross-sectional view of an intermediate condition of a PDC bit provided in accordance with an embodiment of the present invention, the cutaway position being in accordance with FIG. 7;
FIG. 12 is a cross-sectional view of an intermediate condition of a PDC bit having a cutaway position consistent with FIG. 8 in accordance with an embodiment of the present invention;
FIG. 13 is a perspective view of a PDC bit provided in accordance with an embodiment of the present invention at station two;
FIG. 14 is a front view of a PDC bit at station two as provided by an embodiment of the present invention;
FIG. 15 is a cross-sectional view of a PDC bit at station two as provided by an embodiment of the present invention;
FIG. 16 is a cross-sectional view B2-B2 of FIG. 15;
FIG. 17 is a cross-sectional view C2-C2 of FIG. 15;
FIG. 18 is a cross-sectional view D2-D2 of FIG. 15;
FIG. 19 is a cross-sectional view E2-E2 of FIG. 15;
FIG. 20 is an exploded view of a PDC bit provided by an embodiment of the present invention with the outer and inner cutting elements in half-section;
the reference symbols have the following meanings: 10. an outer cutter holder; 11. an outer blade; 101. a first flow passage; 102. an auxiliary liquid spraying port; 103. a first liquid separation chamber; 12. a ring groove; 13. a first step portion; 14. a second step portion; 20. an inner cutter holder; 21. an inner blade; 201. a second flow passage; 202. a bar key; 203. a second liquid dividing cavity; 204. an axial slot; 22. a ball bearing; 23. a first arc-shaped slot; 24. a second arc-shaped slot; 25. an axial slot; 30. a connecting rod; 301. a main water channel; 31. a connecting portion; 311. an external thread; 312. a spline groove; 32. a groove; 33. a convex tooth; 34. a first through hole; 35. a second through hole; 36. a convex ring.
Detailed Description
The embodiments of the present invention are described below with reference to specific embodiments, and other advantages and effects of the present invention will be easily understood by those skilled in the art from the disclosure of the present specification. The invention is capable of other and different embodiments and of being practiced or of being carried out in various ways, and its several details are capable of modification in various respects, all without departing from the spirit and scope of the present invention. It is to be noted that the features in the following embodiments and examples may be combined with each other without conflict.
It should be noted that the drawings provided in the following embodiments are only for illustrating the basic idea of the present invention, and the drawings only show the components related to the present invention rather than the number, shape and size of the components in actual implementation, and the type, quantity and proportion of the components in actual implementation may be changed freely, and the layout of the components may be more complicated.
Referring to fig. 1-20, a PDC bit for use in tight mudstone formations includes:
the outer cutting unit comprises an outer cutter holder 10, wherein a center hole penetrating through the outer cutter holder 10 is formed in the center of the outer cutter holder 10, outer blades 11 are arranged on the crown portion of the outer cutter holder 10, the outer blades 11 extend from the edge of the center hole to the side face of the outer cutter holder 10, and a plurality of outer blades 11 are arranged at intervals along the circumferential direction of the outer cutter holder 10;
the inner cutting unit comprises an inner cutter holder 20, inner blades 21 are arranged at the crown part of the inner cutter holder 20, the inner blades 21 are only distributed on the end surface of the inner cutter holder 20, and a plurality of inner blades 21 are arranged at intervals along the circumferential direction of the inner cutter holder 20; the inner tool apron 20 is movably arranged in the central hole of the outer tool apron 10 along the axial direction, so that the inner cutting unit and the outer cutting unit can be switched between the following two stations: in the first working position, the inner blade 21 axially protrudes for a preset distance relative to the outer blade 11; and a second station, wherein the inner blade 21 is flush with the crown of the outer blade 11, and the crown refers to the front end of the drill bit in the feeding direction; the inner cutter holder 20 is synchronously and rotationally connected with the outer cutter holder 10 along the circumferential direction;
a connecting rod 30, one end of which 30 is provided with a connecting part 31 for connecting a drill rod, and the other end of which is connected with the inner tool apron 20, so as to drive the inner tool apron 20 to feed along the axial direction and rotate along the circumferential direction;
a locking mechanism provided between the inner tool apron 20 and the outer tool apron 10, the locking mechanism being assembled to have a locking station and an unlocking station, and when the locking mechanism is located at the locking station, the outer cutting unit and the inner cutting unit located at the second station can be held at the second station, so that the outer cutting unit can be synchronously fed with the inner cutting unit in a state of the second station; when the locking mechanism is located at an unlocking station, the outer cutting unit can freely move relative to the inner cutting unit along the axial direction, so that when the inner cutting unit is fed, the outer cutting unit can be switched to the first station under the blockage of rock strata and is kept at the first station;
the outer blade 11 and the inner blade 21 are provided with diamond composite cutting teeth 40.
The combined drill bit with the movable part is adopted, wherein the outer cutting unit can move relative to the inner cutting unit along the circumferential direction, and locking and releasing between the two cutting units are realized through the locking mechanism, when fluffy strata are cut, the inner cutting unit is used as a pilot drill bit and protrudes out of the front of the outer cutting unit, the outer cutting unit is used as a hole expanding drill bit and expands the hole of the peripheral area of the inner cutting unit, the integral drilling capability of the drill bit is improved, and at the moment, a larger gap is formed between the inner cutter wing 21 and the outer cutter wing 11, so that mud bags at the front end of the drill bit can be avoided; when cutting a compact mudstone stratum, the inner cutting unit and the outer cutting unit can be kept parallel and level, so that cutting stress is dispersed, the stability of a drilling process is ensured, and edge breakage is avoided. The invention can switch between two stations back and forth so as to adapt to the complex stratum environment with staggered hardness.
As shown in fig. 4, 7, 11, 15, 18 and 20, in a specific embodiment, a blind hole is formed at an end of the inner tool apron 20 away from the inner blade 21, and the connecting rod 30 is inserted into the blind hole; the locking mechanism comprises a ball 22 movably arranged on the side wall of the inner tool apron 20 and an annular groove 12 arranged on the inner wall of the outer tool apron 10, when the inner cutting unit and the outer cutting unit are positioned at the second station, the ball 22 is aligned with the annular groove 12, a radial hole penetrating through the side wall is formed in the side wall of the inner tool apron 20, the ball 22 is movably arranged in the radial hole along the radial direction of the inner tool apron 20, the diameter of the ball 22 is larger than the thickness of the side wall of the inner tool apron 20, a groove 32 is formed in the connecting rod 30 at a position corresponding to the ball 22, the bottom surface of the groove 32 is in smooth transition with the outer wall of the connecting rod 30, the connecting rod 30 is in running fit with the inner tool apron 20 within a preset angle range, so that the connecting rod 30 and the inner tool apron 20 can be switched between a first angle range and a second angle range, when the connecting rod 30 and the inner tool apron 20 are located in the first angle interval, the ball 22 is opposite to the groove 32, and the inner side of the ball 22 can be partially accommodated in the groove 32, so that the outer side of the ball 22 avoids the annular groove 12, and the locking mechanism is located at the unlocking station; when the connecting rod 30 and the inner tool apron 20 are located in a second angular interval, the groove 32 and the ball 22 are circumferentially staggered, so that the ball 22 is pushed into the annular groove 12 by the connecting rod 30, and the locking mechanism is located at the locking station; when the connecting rod 30 is rotated in a first direction relative to the inner holder 20, the two are switched from a first angle interval to a second angle interval, the first direction being the cutting direction of the drill.
As shown in fig. 4-6, 9, 10, 15-17, 20, in one embodiment, the outer wall of the connecting rod 30 is provided with a convex tooth 33, the inner wall of the inner cutter holder 20 is provided with a first arc-shaped groove 23 and a second arc-shaped groove 24 which are matched with the convex tooth 33, the first arc-shaped groove 23 and the second arc-shaped groove 24 are arranged at intervals along the axial direction of the inner cutter holder 20, and the two are communicated through an axial groove 25, the connecting rod 30 is movably connected with the inner tool apron 20 along the axial direction, so that the teeth 33 are switched between the first arc-shaped slot 23 and the second arc-shaped slot 24, when the convex tooth 33 is positioned in the first arc-shaped groove 23, the connecting rod 30 can move between the first angle interval and the second angle interval, when the convex tooth 33 is positioned in the second arc-shaped groove 24, the connecting rod 30 can only move in the first angle interval; the tooth 33 can be moved from the first arc-shaped groove 23 to the second arc-shaped groove 24 when the connecting rod 30 is moved in a first linear direction relative to the inner holder 20, the first linear direction being the feed direction of the drill.
As shown in fig. 4, in a specific embodiment, a main water channel 301 is disposed inside the connecting rod 30, a first liquid distribution chamber 103 is formed between an inner wall of the outer cutter holder 10 and an outer wall of the connecting rod 30, a second liquid distribution chamber 203 is formed between an end of the connecting rod 30 and the inner cutter holder 20, and a first through hole 34 and a second through hole 35, which are respectively communicated with the first liquid distribution chamber 103 and the second liquid distribution chamber 203, are disposed on a side wall of the connecting rod 30; a first flow channel 101 is arranged inside the outer cutter holder 10, a liquid inlet of the first flow channel 101 is communicated with the first liquid dividing cavity 103, a liquid outlet of the first flow channel 101 is formed in the crown of the outer cutter holder 10, and the liquid outlet is positioned between two adjacent outer blades 11; a second flow passage 201 is arranged inside the inner tool apron 20, a liquid inlet of the second flow passage 201 is communicated with the second liquid dividing cavity 203, a liquid outlet of the second flow passage 201 is formed at the end of the inner tool apron 20, and the liquid outlet is located between two adjacent inner blades 21.
As shown in fig. 4 and 20, in a specific embodiment, a convex ring 36 is formed on the connecting rod 30, a first step portion 13 and a second step portion 14 are formed on an inner wall of the outer tool holder 10, an inner ring surface of the first step portion 13 is attached to an outer wall of the connecting rod 30, an inner ring surface of the second step portion 14 is spaced from the outer wall of the connecting rod 30, the first step portion 13 and the second step portion 14 are located on a side close to a crown portion of the outer tool holder 10 relative to the convex ring 36, the inner wall of the outer tool holder 10, the first step portion 13, and the second step portion 14 together define the first liquid separation chamber 103, and when liquid is filled in the first liquid separation chamber 103, a first linear thrust can be generated on the outer tool holder 10.
As shown in fig. 4 and 20, in an embodiment, the liquid inlet of the first flow channel 101 is formed on an inner annular surface of the second stepped portion 14.
As shown in fig. 8, 12 and 19, in a specific embodiment, a closing mechanism is disposed between the connecting rod 30 and the inner tool holder 20, and the closing mechanism is configured to disconnect the water path between the main water path 301 and the second branch chamber 203 when the connecting rod 30 and the inner tool holder 20 are at a first relative preset angle, the first relative preset angle is located in the first angle interval, and connect the water path between the main water path 301 and the second branch chamber 203 when the connecting rod 30 and the inner tool holder 20 are at other relative angles in the first angle interval and the second angle interval.
As shown in fig. 8, 12 and 19, in a specific embodiment, the closing mechanism includes an axial groove 204 formed in an inner wall of the inner tool holder 20, when the connecting rod 30 and the inner tool holder 20 are at other relative angles except for the first relative preset angle in the first angle interval and the second angle interval, the second through hole 35 is opposite to the axial groove 204, and at this time, the second through hole 35 is communicated with the second branch liquid chamber 203 through the axial groove 204; when the connecting rod 30 and the inner tool holder 20 are at the first relative preset angle, the second through hole 35 is staggered with the axial slot 204, and at this time, the second through hole 35 is disconnected with the second liquid dividing chamber 203.
In one embodiment, as shown in fig. 1, a bar key 202 is formed on the inner tool holder 20 extending from the outer end of the inner blade 21 to the side wall of the inner tool holder 20, and a key slot is formed on the inner wall of the outer tool holder 10 for matching with the bar key 202.
In a specific embodiment, as shown in fig. 3, the number of the outer blades 11 is greater than the number of the inner blades 21, and each inner blade 21 corresponds to one outer blade 11 aligned in the radial direction, the inner ends of the outer blades 11 aligned with the inner blades 21 are provided with auxiliary liquid injection ports 102, the auxiliary liquid injection ports 102 are disposed toward the outer wall of the bar-shaped key 202, and the auxiliary liquid injection ports 102 are communicated with the first flow channel 101. The auxiliary liquid injection port 102 can clean the surface of the bar key 202 to prevent sand from obstructing the relative movement between the inner tool holder 20 and the outer tool holder 10.
The specific working process and principle of the invention are as follows:
assuming that the initial state of the drill bit is station one, as shown in fig. 1-8, the drill bit is lowered into the well at this time, and the fluffy stratum can be directly cut; when a tight stratum is met, firstly stopping feeding, then rotating the drill rod along the reverse direction of the first direction to enable the connecting rod 30 to rotate to the state shown in fig. 9-12, the connecting rod 30 and the inner cutter base 20 are in a first relative preset angle, at the same time, the main water channel 301 is disconnected from the second liquid dividing cavity 203, see fig. 12, water pressure is completely acted on the first liquid dividing cavity 103, so that great thrust is generated on the outer cutter base 10, the outer cutter base 10 tends to move downwards, meanwhile, the drill rod is lifted upwards for a certain distance, at the same time, because the outer cutter base 10 is not limited by the axial direction of the inner cutter base 20, the outer cutter base 10 can gradually move towards the crown part of the inner cutter base 20 until the end parts of the outer cutter base and the inner cutter base are flush, in the process that the connecting rod 30 is lifted upwards, the convex teeth 33 are simultaneously moved from the second arc-shaped grooves 24 to the first arc-shaped grooves 23, at the time, the drill rod is rotated along the first direction, and the convex teeth 33 can be clamped into the first arc-shaped grooves 23, in the extreme position of the rotation of the connecting rod 30 relative to the inner tool apron 20, the ball 22 can be pushed into the annular groove 12, so that the outer tool apron 10 and the inner tool apron 20 are axially fixed, and the outer cutting unit and the inner cutting unit can drill on the same section by continuously feeding the drill rod downwards. When encountering fluffy stratum again, the drill rod rotates reversely along the first direction again, so that the connecting rod 30 and the inner tool apron 20 are switched to a first angle interval, then the drill rod is driven to feed downwards, at the moment, the outer tool apron 10 and the inner tool apron 20 are blocked by rock strata and are kept still, the connecting rod 30 moves downwards relative to the inner tool apron 20, the convex teeth 33 move into the second arc-shaped grooves 24 again, finally, the drill rod is driven to rotate along the first direction again, the drill rod is driven to feed downwards simultaneously, at the moment, the connecting rod 30 and the inner tool apron 20 can be kept in the first angle interval because the convex teeth 33 are positioned in the second arc-shaped grooves 24, so that the locking mechanism keeps an unlocking state, the outer tool apron 10 loses the axial limitation of the inner tool apron 20 and is blocked by the rock strata until the inner tool apron 20 protrudes to a first station relative to the outer tool apron 10, at the moment, the convex ring 36 on the connecting rod 30 is blocked with the second step part 14 on the inner side of the outer tool apron 10, thereby driving the outer cutter seat 10 downward again. Based on the principle, the drill bit can be repeatedly adjusted between the two stations, the drill bit does not need to be frequently replaced in a complex stratum environment, and the drilling efficiency is improved.
It should be noted that, in the present invention, since the drill rod is required to be capable of driving the connecting rod 30 to rotate forward and backward at the same time, a special connecting structure is adopted, specifically, the connecting portion 31 includes an external thread 311 and a spline groove 312 which are arranged on an outer wall of the connecting rod 30, the drill rod can rotate forward and backward synchronously with the connecting rod 30 through a spline, a nut block is rotatably arranged on the drill rod, and the nut block and the external thread 311 form a threaded connection, so as to realize axial tensioning of the drill rod and the connecting rod 30. In the invention, the hardness of the rock stratum can be judged by the feeding pressure and the feeding speed of the drill rod, for example, under the same pressure, the faster the feeding speed is, the softer the rock stratum is, the slower the feeding speed is, the harder the rock stratum is, besides, the rock stratum properties of different depths can be determined by early exploration (such as ultrasonic detection), and then the proper drill bit station is selected directly according to the drilling depth.
The foregoing embodiments are merely illustrative of the principles and utilities of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or change the above-mentioned embodiments without departing from the spirit and scope of the present invention. Accordingly, it is intended that all equivalent modifications or changes which can be made by those skilled in the art without departing from the spirit and technical spirit of the present invention be covered by the claims of the present invention.
Claims (10)
1. A PDC bit adapted for use in densifying mudstone formations, comprising:
the external cutting unit comprises an outer cutter holder (10), wherein a central hole penetrating through the outer cutter holder (10) is formed in the center of the outer cutter holder (10), outer cutter wings (11) are arranged on the crown portion of the outer cutter holder (10), the outer cutter wings (11) extend to the side face of the outer cutter holder (10) from the edge of the central hole, and a plurality of outer cutter wings (11) are arranged at intervals along the circumferential direction of the outer cutter holder (10);
the inner cutting unit comprises an inner cutter holder (20), inner blades (21) are arranged at the crown part of the inner cutter holder (20), the inner blades (21) are only distributed on the end surface of the inner cutter holder (20), and a plurality of inner blades (21) are arranged at intervals along the circumferential direction of the inner cutter holder (20); the inner cutter holder (20) is movably arranged in a central hole of the outer cutter holder (10) along the axial direction, so that the inner cutting unit and the outer cutting unit can be switched between the following two stations: the first station, the inner blade (21) axially protrudes for a preset distance relative to the outer blade (11); and a second station, wherein the inner blade (21) is flush with the crown of the outer blade (11); the inner cutter holder (20) is connected with the outer cutter holder (10) in a synchronous rotating manner along the circumferential direction;
the connecting rod (30) is provided with a connecting part (31) for connecting a drill rod at one end, and the other end of the connecting rod (30) is connected with the inner cutter holder (20) so as to drive the inner cutter holder (20) to feed along the axial direction and rotate along the circumferential direction;
the locking mechanism is arranged between the inner cutter holder (20) and the outer cutter holder (10), is assembled to be provided with a locking station and an unlocking station, and can keep the outer cutting unit and the inner cutting unit which are positioned at the second station in the second station when the locking mechanism is positioned at the locking station so that the outer cutting unit and the inner cutting unit can be synchronously fed in the state of the second station; when the locking mechanism is located at an unlocking station, the outer cutting unit can freely move relative to the inner cutting unit along the axial direction, so that when the inner cutting unit is fed, the outer cutting unit can be switched to the first station under the blockage of rock strata and is kept at the first station;
the outer blade (11) and the inner blade (21) are provided with diamond composite cutting teeth (40).
2. The PDC drill bit suitable for tight mudstone formations according to claim 1, wherein the inner cutter holder (20) is provided with a blind hole at one end far away from the inner blades (21), and the connecting rod (30) is inserted into the blind hole; the locking mechanism comprises a ball (22) movably arranged on the side wall of the inner cutter holder (20) and an annular groove (12) arranged on the inner wall of the outer cutter holder (10), when the inner cutting unit and the outer cutting unit are positioned at the second station, the ball (22) is aligned with the annular groove (12), a radial hole penetrating through the side wall is formed in the side wall of the inner cutter holder (20), the ball (22) is arranged in the radial hole along the radial movement of the inner cutter holder (20), the diameter of the ball (22) is greater than the thickness of the side wall of the inner cutter holder (20), a groove (32) is formed in the position, corresponding to the ball (22), of the connecting rod (30), the bottom surface of the groove (32) is in smooth transition with the outer wall of the connecting rod (30), and the connecting rod (30) is in running fit with the inner cutter holder (20) within a preset angle range, the connecting rod (30) and the inner tool apron (20) can be switched between a first angle interval and a second angle interval, when the connecting rod (30) and the inner tool apron (20) are located in the first angle interval, the ball (22) is opposite to the groove (32), the inner side of the ball (22) can be partially accommodated in the groove (32), so that the outer side of the ball (22) avoids the annular groove (12), and the locking mechanism is located at the unlocking station; when the connecting rod (30) and the inner tool apron (20) are located in a second angle interval, the groove (32) and the ball (22) are staggered with each other along the circumferential direction, so that the ball (22) is pushed into the annular groove (12) by the connecting rod (30), and the locking mechanism is located at the locking station; when the connecting rod (30) rotates relative to the inner tool apron (20) along a first direction, the two angle sections are switched from a first angle section to a second angle section, and the first direction is the cutting direction of the drill bit.
3. The PDC drill bit suitable for tight mudstone formations according to claim 2, wherein the connecting rod (30) is provided with convex teeth (33) on the outer wall thereof, the inner cutter holder (20) is provided with first arc-shaped slots (23) and second arc-shaped slots (24) on the inner wall thereof, the first arc-shaped slots (23) and the second arc-shaped slots (24) are axially spaced along the inner cutter holder (20) and are communicated with each other through an axial slot (25), the connecting rod (30) is axially movably connected with the inner cutter holder (20) so as to switch the convex teeth (33) between the first arc-shaped slots (23) and the second arc-shaped slots (24), and when the convex teeth (33) are located in the first arc-shaped slots (23), the connecting rod (30) is capable of moving between the first angle interval and the second angle interval, when the convex tooth (33) is positioned in the second arc-shaped groove (24), the connecting rod (30) can only move in the first angle interval; when the connecting rod (30) moves relative to the inner cutter holder (20) along a first linear direction, which is the feed direction of the drill, the convex tooth (33) can be moved from the first arc-shaped groove (23) to the second arc-shaped groove (24).
4. The PDC drill bit suitable for compact mudstone formations according to claim 3, wherein the connecting rod (30) is internally provided with a main water channel (301), a first liquid dividing cavity (103) is formed between the inner wall of the outer cutter holder (10) and the outer wall of the connecting rod (30), a second liquid dividing cavity (203) is formed between the end of the connecting rod (30) and the inner cutter holder (20), and a first through hole (34) and a second through hole (35) which are respectively communicated with the first liquid dividing cavity (103) and the second liquid dividing cavity (203) are formed in the side wall of the connecting rod (30); a first flow channel (101) is arranged in the outer cutter holder (10), a liquid inlet of the first flow channel (101) is communicated with the first liquid dividing cavity (103), a liquid outlet of the first flow channel (101) is formed in the crown of the outer cutter holder (10), and the liquid outlet is positioned between two adjacent outer blades (11); the inner cutter holder (20) is internally provided with a second runner (201), a liquid inlet of the second runner (201) is communicated with the second liquid dividing cavity (203), a liquid outlet of the second runner (201) is formed at the end part of the inner cutter holder (20), and the liquid outlet is positioned between two adjacent inner blades (21).
5. The PDC bit suitable for use in tight mudstone formations of claim 4, a convex ring (36) is formed on the connecting rod (30), a first step part (13) and a second step part (14) are formed on the inner wall of the outer cutter holder (10), the inner ring surface of the first step part (13) is attached to the outer wall of the connecting rod (30), the inner ring surface of the second step part (14) and the outer wall of the connecting rod (30) are arranged at intervals, the first step part (13) and the second step part (14) are positioned on one side close to the crown part of the outer tool apron (10) relative to the convex ring (36), the convex ring (36), the inner wall of the outer cutter holder (10), the first step part (13) and the second step part (14) jointly enclose to form the first liquid separation cavity (103), when the first liquid separation cavity (103) is filled with liquid, a thrust in a first linear direction can be generated on the outer cutter holder (10).
6. The PDC bit suitable for tight mudstone formations of claim 5 wherein the inlet of the first flow channel (101) is formed on an inner annular surface of the second step portion (14).
7. The PDC bit suitable for tight mudstone formations according to claim 6, wherein a closing mechanism is provided between the connecting rod (30) and the inner cutter holder (20), the closing mechanism being fitted to enable a water path between the main water path (301) and the second diversion chamber (203) to be disconnected when the connecting rod (30) and the inner cutter holder (20) are at a first relative preset angle, the first relative preset angle being within the first angular interval, and to enable a water path between the main water path (301) and the second diversion chamber (203) to be connected when the connecting rod (30) and the inner cutter holder (20) are at other relative angles within the first and second angular intervals.
8. The PDC drill bit suitable for tight mudstone formations according to claim 7, wherein the closing mechanism comprises an axial groove (204) formed in the inner wall of the inner tool holder (20), and when the connecting rod (30) and the inner tool holder (20) are at other relative angles except the first relative preset angle in the first angle interval and the second angle interval, the second through hole (35) is opposite to the axial groove (204), and the second through hole (35) is communicated with the second diversion cavity (203) through the axial groove (204); when the connecting rod (30) and the inner cutter holder (20) are at the first relative preset angle, the second through hole (35) and the axial strip groove (204) are staggered, and at the moment, the second through hole (35) is disconnected with the second liquid dividing cavity (203).
9. The PDC drill bit suitable for tight mudstone formations according to claim 8, wherein the inner cutter base (20) is formed with a bar key (202) extending from the outer end of the inner blade (21) to the side wall of the inner cutter base (20), and the inner wall of the outer cutter base (10) is formed with a key slot for cooperating with the bar key (202).
10. The PDC bit for a tight mudstone formation according to claim 9, characterized in that the number of the outer blades (11) is greater than that of the inner blades (21), each inner blade (21) has one outer blade (11) aligned radially therewith, the inner ends of the outer blades (11) aligned with the inner blades (21) are provided with auxiliary liquid injection ports (102), the auxiliary liquid injection ports (102) are arranged toward the outer wall of the bar-shaped key (202), and the auxiliary liquid injection ports (102) are communicated with the first flow channel (101).
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210500029.0A CN114592796B (en) | 2022-05-10 | 2022-05-10 | PDC drill bit suitable for tight mudstone stratum |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202210500029.0A CN114592796B (en) | 2022-05-10 | 2022-05-10 | PDC drill bit suitable for tight mudstone stratum |
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| CN114592796A CN114592796A (en) | 2022-06-07 |
| CN114592796B true CN114592796B (en) | 2022-07-12 |
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| CN202210500029.0A Active CN114592796B (en) | 2022-05-10 | 2022-05-10 | PDC drill bit suitable for tight mudstone stratum |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN116220560B (en) * | 2023-05-10 | 2023-07-07 | 陕西延长石油矿业有限责任公司 | Intelligent drilling tool for weakly cemented stratum |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0113771D0 (en) * | 2000-06-07 | 2001-07-25 | Smith International | Drill bit |
| CN101611211A (en) * | 2007-02-16 | 2009-12-23 | 贝克休斯公司 | Be used to collect the method and apparatus of drill bit performance data |
| CN202325250U (en) * | 2011-08-29 | 2012-07-11 | 中国石油集团川庆钻探工程有限公司 | Plastic stratum well-drilling drilling tool structure |
| CN104806170A (en) * | 2015-05-13 | 2015-07-29 | 西南石油大学 | Drilling and coal mining large-variable-diameter reaming bit |
| CN207260959U (en) * | 2017-08-14 | 2018-04-20 | 四川弘毅智慧知识产权运营有限公司 | A kind of PDC composite drill bits for improving drill bit center portion efficiency of breaking rock |
| CN109184728A (en) * | 2018-10-30 | 2019-01-11 | 浙江科技学院 | The vertical combined type multidimensional of flank-for soft or hard stratum freezes drilling method |
| CN209308635U (en) * | 2019-01-14 | 2019-08-27 | 成都百施特金刚石钻头有限公司 | PDC drill bit with multiple stage crushing function |
| CN110359852A (en) * | 2018-02-10 | 2019-10-22 | 西南石油大学 | Combined type diamond bit with fixed buffer structure |
| CN210798850U (en) * | 2019-10-17 | 2020-06-19 | 嘉力臣工程设备(深圳)有限公司 | Soil-rock integrated drill bit |
| CN111764832A (en) * | 2020-07-14 | 2020-10-13 | 江苏煤炭地质勘探三队 | PDC drill bit suitable for crushing hard basalt stratum |
| CN114109380A (en) * | 2021-11-30 | 2022-03-01 | 中国矿业大学 | Composite cutter head device suitable for hard rock crushing and use method thereof |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7455125B2 (en) * | 2005-02-22 | 2008-11-25 | Baker Hughes Incorporated | Drilling tool equipped with improved cutting element layout to reduce cutter damage through formation changes, methods of design and operation thereof |
-
2022
- 2022-05-10 CN CN202210500029.0A patent/CN114592796B/en active Active
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB0113771D0 (en) * | 2000-06-07 | 2001-07-25 | Smith International | Drill bit |
| CN101611211A (en) * | 2007-02-16 | 2009-12-23 | 贝克休斯公司 | Be used to collect the method and apparatus of drill bit performance data |
| CN202325250U (en) * | 2011-08-29 | 2012-07-11 | 中国石油集团川庆钻探工程有限公司 | Plastic stratum well-drilling drilling tool structure |
| CN104806170A (en) * | 2015-05-13 | 2015-07-29 | 西南石油大学 | Drilling and coal mining large-variable-diameter reaming bit |
| CN207260959U (en) * | 2017-08-14 | 2018-04-20 | 四川弘毅智慧知识产权运营有限公司 | A kind of PDC composite drill bits for improving drill bit center portion efficiency of breaking rock |
| CN110359852A (en) * | 2018-02-10 | 2019-10-22 | 西南石油大学 | Combined type diamond bit with fixed buffer structure |
| CN109184728A (en) * | 2018-10-30 | 2019-01-11 | 浙江科技学院 | The vertical combined type multidimensional of flank-for soft or hard stratum freezes drilling method |
| CN209308635U (en) * | 2019-01-14 | 2019-08-27 | 成都百施特金刚石钻头有限公司 | PDC drill bit with multiple stage crushing function |
| CN210798850U (en) * | 2019-10-17 | 2020-06-19 | 嘉力臣工程设备(深圳)有限公司 | Soil-rock integrated drill bit |
| CN111764832A (en) * | 2020-07-14 | 2020-10-13 | 江苏煤炭地质勘探三队 | PDC drill bit suitable for crushing hard basalt stratum |
| CN114109380A (en) * | 2021-11-30 | 2022-03-01 | 中国矿业大学 | Composite cutter head device suitable for hard rock crushing and use method thereof |
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| Publication number | Publication date |
|---|---|
| CN114592796A (en) | 2022-06-07 |
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