CN111005685B

CN111005685B - Gear wheel-PDC composite sleeve milling bit

Info

Publication number: CN111005685B
Application number: CN201911346956.6A
Authority: CN
Inventors: 易畅; 李晋秦; 文永川; 张晓华; 梁洁; 赵维宁; 张一鹏
Original assignee: Sichuan Gemstone Machinery Petroleum Bit Co ltd
Current assignee: Sichuan Gemstone Machinery Petroleum Bit Co.,Ltd.; China National Petroleum Corp
Priority date: 2019-12-24
Filing date: 2019-12-24
Publication date: 2020-11-24
Anticipated expiration: 2039-12-24
Also published as: CN111005685A

Abstract

The invention discloses a roller cone-PDC composite sleeve milling drill bit, which belongs to an oil field drilling tool and comprises a connecting part and a drill bit body, wherein the end part of the drill bit body is provided with a parabolic notch; the end part of the drill bit body is welded with blades, each blade spans the top end part of the drill bit body and is arc-shaped, and the thickness of the blade in the inner surface part and the outer surface part of the drill bit body is gradually reduced to the end surface of the drill bit body; PDC cutting teeth are arranged on the blades; a righting belt is fixed on the inner surface of the drill bit body at the upper end of the notch; the inner surface and the outer surface of the drill body at the notch are respectively provided with a mounting groove, through holes are formed in the two mounting grooves, a gear bearing is mounted in each through hole, and a gear which rotates relative to the bearing is sleeved on each gear bearing; the cone is embedded with milling teeth, the end surface of the cone arranged on the inner surface of the bit body is set to be a gauge surface, and gauge teeth are arranged on the gauge surface. This scheme can be smashed the cement bits in the drilling fluid gushes out the passageway through the gear wheel to improve the drilling fluid and gush out speed.

Description

Gear wheel-PDC composite sleeve milling bit

Technical Field

The invention relates to an oil field drilling tool, in particular to a roller cone-PDC composite sleeve milling bit.

Background

The well repair is mainly to detect and repair a series of faults such as insufficient yield and poor quality of pipe wells such as oil and gas wells, geothermal wells, water source wells and the like, so that the fault wells or the wells which are scrapped are operated again to put into production. At present, oil-gas wells, geothermal wells, water wells and the like which have faults can not normally run for production, most of the oil-gas wells, the geothermal wells, the water wells and the like are deformed or damaged by casing pipes, so that sand gushes in the wells to block screen pipes of oil and water taking sections, and the phenomenon of insufficient yield is caused.

And (3) repairing the old well according to the condition, trepanning cement between the guide pipe and the guide pipe or between the guide pipe and the stratum of the petroleum and natural gas well, taking out the casing pipe, and setting the casing pipe again for cementing and well cementation so as to achieve the purpose of improving the yield. The thickness of the blade part in the drill bit body and the outer surface part of the existing casing drill bit for well repair is limited, so that a formed drilling fluid gushing channel is small, and if the carried cement impurities are too much or too large, the channel is blocked, and the drilling progress is influenced.

Disclosure of Invention

Aiming at the defects in the prior art, the cone-PDC composite milling bit provided by the invention can crush cement chips in a drilling fluid discharge channel through a cone so as to improve the discharge speed of the drilling fluid.

In order to achieve the purpose of the invention, the invention adopts the technical scheme that:

the cone-PDC composite sleeve milling drill bit comprises a connecting part and a drill bit body, wherein the connecting part and the drill bit body are cylindrical; the connecting part comprises a reinforcing ring and a connector which is connected with the drill body into a whole, and the inner surface and the outer surface of the connector are both provided with threads; the inner diameter of the connector is equal to that of the drill bit body, and the outer diameter of the connector is smaller than that of the drill bit body; one end of the reinforcing ring is sleeved on the drill bit body at the connecting head and is welded with the drill bit body into a whole; the length of the part of the reinforcing ring, which is not in contact with the drill body, is greater than that of the connecting head, and internal threads are tapped on the inner surface of the reinforcing ring;

the end part of the drill bit body is provided with a parabolic notch, and the connecting line length of the tail end of the notch is equal to the diameter of the drill bit body; the end part of the drill bit body is welded with blades, each blade spans the top end part of the drill bit body and is arc-shaped, and the thickness of the blade in the inner surface part and the outer surface part of the drill bit body is gradually reduced to the end surface of the drill bit body; PDC cutting teeth are arranged on the blades, and the distance between the outer surface of the reinforcing ring and the central axis of the bit body is smaller than the distance between the outer sides of the blades and the central axis of the bit body;

a centralizing belt is fixed on the inner surface of the drill bit body at the upper end of the notch, gauge teeth are arranged on the gauge surface of the centralizing belt, and the end surface of the centralizing belt and the inner wall of the drill bit body are in cambered surface transition; the inner surface and the outer surface of the drill body at the notch are respectively provided with a mounting groove, through holes are formed in the two mounting grooves, a gear bearing is mounted in each through hole, and a gear which rotates relative to the bearing is sleeved on each gear bearing;

the cone is embedded with milling teeth, the end surface of the cone arranged on the inner surface of the bit body is arranged into a gauge surface, and gauge teeth are arranged on the gauge surface; the thickness of the mounting groove extended from the roller cone on the inner surface of the bit body is equal to that of the centralizing belt; the thickness of the cone extending out of the mounting groove without the gauge protection teeth is larger than that of the part of the blade on the outer surface of the bit body.

The invention has the beneficial effects that: according to the scheme, the gear wheels are respectively arranged on the inner surface and the outer surface of the drill bit body at the groove opening, and the cement chips carried by the drilling fluid can be crushed due to the gear wheels, so that the particle size of the cement chips is far smaller than the width of a channel, and the cement chips are ensured to flow out quickly along with the drilling fluid; the thickness of the cone on the outer surface of the bit body, which extends out of the mounting groove, is larger than that of the part of the blade on the outer surface of the bit body, so that cement scraps can be crushed by the cone in the rotating process, and a channel can be widened to improve the outflow speed of drilling fluid.

This scheme can make things convenient for sheathed tube to embolia fast at the notch that bit body tip set up on the one hand, and on the other hand can also increase the import width that the inboard drilling fluid of bit body flowed out the passageway, realizes that the drilling fluid carries the cement bits and flows into the passageway fast, avoids a large amount of cement bits to pile up in wing department, influences the cutting.

The unique setting of connecting portion structure for the surface all can be connected with the drilling tool through the screw thread in the cover milling drill bit upper end, has guaranteed the stability that connecting portion connect, has reduced the risk that falls to bore.

Drawings

FIG. 1 is a schematic diagram of a roller cone-PDC composite shell milling bit in which the PDC cutters are shown schematically.

FIG. 2 is a cross-sectional view of a roller cone-PDC composite shell milling bit with PDC cutters being simplified.

FIG. 3 is a schematic diagram of an embodiment of a PDC cutter.

FIG. 4 is a schematic diagram of another embodiment of a PDC cutter.

Wherein, 1, a connecting part; 11. a reinforcing ring; 12. a connector; 2. a bit body; 21. a notch; 22. a blade; 221. PDC cutting teeth; 2211. a bevel; 2212. a protrusion; 2213. a chip groove; 2214. a half cylinder; 2215. an arc-shaped body; 2216. a transition surface; 23. a centralizing band; 231. a gauge surface; 232. gauge protection teeth; 24. mounting grooves; 25. a gear bearing; 26. a cone.

Detailed Description

The following description of the embodiments of the present invention is provided to facilitate the understanding of the present invention by those skilled in the art, but it should be understood that the present invention is not limited to the scope of the embodiments, and it will be apparent to those skilled in the art that various changes may be made without departing from the spirit and scope of the invention as defined and defined in the appended claims, and all matters produced by the invention using the inventive concept are protected.

As shown in fig. 1, the roller cone-PDC composite sleeve milling drill bit of the present disclosure includes a connecting portion 1 and a bit body 2, wherein the connecting portion 1 and the bit body 2 are both cylindrical; as shown in fig. 2, the connecting portion 1 includes a reinforcing ring 11 and a connecting head 12 integrally connected to the bit body 2, and the inner and outer surfaces of the connecting head 12 are threaded; the inner diameter of the connector 12 is equal to the inner diameter of the bit body 2, and the outer diameter of the connector 12 is smaller than the outer diameter of the bit body 2; one end of the reinforcing ring 11 is sleeved on the drill bit body 2 at the connecting head 12 and is welded with the drill bit body 2 into a whole; the reinforcing ring 11 has a length greater than that of the connecting head 12 at the portion not in contact with the bit body 2, and has an inner surface tapped with an internal thread.

After the reinforcing ring 11 is introduced, the stability of connection between the sleeve milling drill bit and the drilling tool can be improved, and therefore the risk of drill falling is reduced.

A parabolic notch 21 is formed in the end part of the bit body 2, and the connecting line length of the tail end of the notch 21 is equal to the diameter of the bit body 2; the notch 21 in the scheme can facilitate quick sleeve sleeving, the width of the inlet of the drilling fluid outflow channel on the inner side of the bit body 2 can be increased, and the discharge speed of the drilling fluid is increased.

In order to improve the shock resistance of the notch 21, the notch surface of the notch 21 is preferably a tangent plane facing the milling direction, and an inner grinding layer or hard alloy particles are paved and welded on the tangent plane.

Referring to fig. 1 and 2 again, blades 22 are welded at the end of the bit body 2, each blade 22 spans the top end part of the bit body 2 to form an arc shape, and the thickness of the blade 22 at the inner surface part and the outer surface part of the bit body 2 is gradually reduced to the end surface of the bit body 2; the blade 22 is configured in an arc shape, and the impact resistance of the blade 22 can be improved because a relatively sharp structure does not exist.

PDC cutting teeth 221 are arranged on the blades 22, and the distance between the outer surface of the reinforcing ring 11 and the central axis of the bit body 2 is smaller than the distance between the outer sides of the blades 22 and the central axis of the bit body 2; the distance is set here so that the reinforcing ring 11 provided can be prevented from blocking the passage outside the drill body 2.

As shown in fig. 2, a stabilizing belt 23 is fixed on the inner surface of the bit body 2 at the upper end of the notch 21, gauge teeth 232 are arranged on a gauge surface 231 of the stabilizing belt 23, and the end surface of the stabilizing belt 23 is in arc transition with the inner wall of the bit body 2; the inside and outside surface of the bit body 2 of notch 21 department has respectively seted up a mounting groove 24, has all seted up the through-hole in two mounting grooves 24, installs cone bearing 25 in the through-hole, and the cover is equipped with the rotatory cone 26 of relative bearing on the cone bearing 25.

The roller cone 26 on the outer surface of the bit body 2 is hemispherical, the roller cone 26 on the inner surface of the bit body 2 is a structure of hemispherical shape with arc-shaped end parts cut off to form a round top surface, and the round surfaces on both ends of the roller cone 26 on the inner surface of the bit body 2 are parallel to each other.

The cone 26 is embedded with milling teeth, and the end surface of the cone 26 arranged on the inner surface of the bit body 2 is provided with a gauge surface 231 (the round top surface of the cone 26) on which gauge teeth 232 are arranged; the thickness of the cone 26 extending out of the mounting groove 24 on the inner surface of the bit body 2 is equal to that of the centralizing belt 23; the arrangement of the centralizing belt 23 can avoid the deviation of a milling drill when the cement sheath is milled.

The thickness of the cone 26 without the gauge teeth 232 extending out of the mounting groove 24 is greater than the thickness of the portion of the blades 22 on the outer surface of the bit body 2; after the arrangement, the cone 26 can not only crush cement chips in the rotating process, but also widen the channel so as to improve the outflow speed of drilling fluid.

As shown in fig. 3, the PDC cutter 221 is a cylinder, and has an inclined surface 2211 at one end, a plurality of semi-spherical protrusions 2212 are uniformly distributed on the inclined surface 2211, and all gaps between the protrusions 2212 are communicated with each other to form a chip groove 2213.

When the PDC cutting tooth 221 milling tool shown in fig. 3 is adopted, the inclined surface 2211 faces the rotation direction of the drill bit, and when the milling tool is used, the cutting force of the PDC cutting tooth 221 can be improved due to the arrangement of the plurality of protrusions 2212, on one hand, cement chips generated in the cutting process can be rapidly discharged through the channel due to the existence of the chip discharge groove 2213, and on the other hand, the rapid cooling of the PDC cutting tooth 221 can be accelerated due to the fact that drilling fluid flows through the chip discharge groove 2213.

As shown in fig. 4, the PDC cutting tooth 221 includes a half cylinder 2214 and an arc 2215 integrally connected to the half cylinder 2214, an end surface of the half cylinder 2214 is formed by at least three transition surfaces 2216 obliquely intersecting upwards and forwards, adjacent transition surfaces 2216 are in smooth transition through an arc surface, and a smooth round top surface is disposed at the intersection of all the transition surfaces 2216.

In fig. 4, the circular top surface of the PDC cutter 221 and the arc surface between the adjacent transition surfaces 2216 are in transition, so that the impact resistance of the contact surface of the PDC cutter 221 and a cement ring can be improved, and the transition surfaces 2216 can enable the PDC cutter 221 to be in contact with the cement ring from a plurality of angles, so that the cutting capacity of the PDC cutter 221 is improved, and the milling efficiency is improved.

In implementation, it is preferable that each transition surface 2216 is uniformly provided with a plurality of hemispheric protrusions 2212 which are not in contact with each other, and all gaps between the protrusions 2212 are communicated with each other to form a chip groove 2213. The projections 2212 and flutes 2213 herein function in the same manner as the projections 2212 and flutes 2213 of the PDC cutter 221 shown in fig. 3 and will not be described further herein.

The included angle between transition surface 2216 and the axis of half-cylinder 2214 is 35 °, and the projection length of transition surface 2216 on the axis of half-cylinder 2214 is equal to one fifth of the length of half-cylinder 2214; the height of the projection 2212 is 0.6-1.2 mm. The included angle of the transition surfaces 2216 is set, so that on one hand, the junction of the three transition surfaces 2216 can be prevented from being too sharp, the PDC cutting teeth 221 are easy to damage during sleeve milling, and on the other hand, the transition surfaces 2216 are not too steep, and the contact area between the transition surfaces 2216 and the cutting positions can be increased.

In conclusion, the cone-PDC composite sleeve milling drill bit provided by the scheme can crush cement chips in a drilling fluid discharge channel and widen the channel simultaneously by matching the cones 26 on the inner surface and the outer surface of the drill bit body 2, so that the discharge speed of the drilling fluid is ensured.

Claims

1. The cone-PDC composite sleeve milling bit comprises a connecting part and a bit body, wherein the connecting part and the bit body are both cylindrical; the drill bit is characterized in that the connecting part comprises a reinforcing ring and a connector which is connected with the drill bit body into a whole, and threads are respectively tapped on the inner surface and the outer surface of the connector; the inner diameter of the connector is equal to that of the drill bit body, and the outer diameter of the connector is smaller than that of the drill bit body; one end of the reinforcing ring is sleeved on the drill bit body at the connecting head and is welded with the drill bit body into a whole; the length of the part, which is not contacted with the drill body, of the reinforcing ring is greater than that of the connecting head, and internal threads are tapped on the inner surface of the reinforcing ring;

the end part of the drill bit body is provided with a parabolic notch, and the length of a connecting line of the tail end of the notch is equal to the diameter of the drill bit body; the end part of the drill bit body is welded with blades, each blade spans the top end part of the drill bit body and is arc-shaped, and the thickness of the blade in the inner surface part and the outer surface part of the drill bit body is gradually reduced to the end surface of the drill bit body; PDC cutting teeth are arranged on the blades, and the distance between the outer surface of the reinforcing ring and the central axis of the bit body is smaller than the distance between the outer sides of the blades and the central axis of the bit body;

a centralizing belt is fixed on the inner surface of the drill bit body at the upper end of the notch, gauge teeth are arranged on the gauge surface of the centralizing belt, and the end surface of the centralizing belt and the inner wall of the drill bit body are in cambered surface transition; the inner surface and the outer surface of the drill bit body at the notch are respectively provided with a mounting groove, through holes are formed in the two mounting grooves, a gear bearing is mounted in each through hole, and a gear which rotates relative to the bearing is sleeved on each gear bearing;

the cone is embedded with milling teeth, the end surface of the cone arranged on the inner surface of the bit body is set to be a gauge surface, and gauge teeth are arranged on the gauge surface; the thickness of the mounting groove extended from the roller cone on the inner surface of the bit body is equal to that of the centralizing belt; the thickness of the cone extending out of the mounting groove without the gauge protection teeth is larger than that of the part of the blade on the outer surface of the bit body.

2. The roller cone-PDC composite shell milling bit according to claim 1, wherein the notch surface of the notch is a milling-direction cut surface on which an inner wear layer or cemented carbide particles are welded.

3. The roller cone-PDC composite milling bit according to claim 1, wherein the PDC cutter is a cylinder, one end of the PDC cutter is provided with an inclined surface, a plurality of hemispherical protrusions which are not in contact with each other are uniformly distributed on the inclined surface, and all gaps between the protrusions are communicated with each other to form a chip removal groove.

4. The roller cone-PDC composite milling bit of claim 1, wherein the PDC cutting teeth comprise a semi-cylinder and an arc-shaped body connected with the semi-cylinder into a whole, the end surface of the semi-cylinder is formed by at least three transition surfaces which are obliquely intersected upwards and forwards, the adjacent transition surfaces are smoothly transited through the arc surface, and smooth round top surfaces are arranged at the junctions of all the transition surfaces.

5. The roller cone-PDC composite shell milling bit of claim 4, wherein a plurality of hemispheric protrusions which are not in contact with each other are uniformly distributed on each transition surface, and all gaps between the protrusions are communicated with each other to form a chip groove.

6. The roller cone-PDC composite shell milling bit of claim 4 or 5, wherein the angle between the transition surface and the axis of the half cylinder is 35 °, and the length of the projection of the transition surface on the axis of the half cylinder is equal to one fifth of the length of the half cylinder.

7. The roller cone-PDC composite shell milling bit of claim 3 or 5, wherein the height of the protuberance is 0.6-1.2 mm.