CN211339692U

CN211339692U - Mould for protecting hard alloy of PDC drill tooth from being corroded in cobalt removal process

Info

Publication number: CN211339692U
Application number: CN201922490095.0U
Authority: CN
Inventors: 范萍; 李家益; 张锦睿; 姬荣斌
Original assignee: Chengdu Huanbao Technology Co ltd
Current assignee: Chengdu Huanbao Technology Co ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-08-25
Anticipated expiration: 2029-12-31

Abstract

The utility model relates to a protection PDC bores mould that tooth carbide was corroded at cobalt removal process, including the mould body, the inside of mould body is opened there is the drill bit and is held the chamber, and open the bottom that the drill bit held the chamber has a plurality of through-holes, and open the upper end that the drill bit held the chamber has conical surface groove, and the drill bit all coats on the inner wall that holds the chamber and the bottom surface and has the protective coating, and the drill bit holds the intracavity in is arranged in to the carbide part of PDC drill bit, and the carbide part highly equals the degree of depth that the drill bit held. The utility model has the advantages that: the hard alloy part of the PDC drill bit is arranged in the drill bit containing cavity, the height of the drill bit containing cavity is ensured to be consistent with the height of the hard alloy part, the hard alloy part is protected, in addition, a conical groove is arranged at the upper end of the drill bit containing cavity, a coating inside the die has a hydrophobic effect, and a corrosion blind area can be formed on the conical groove. When the polycrystalline diamond part is in contact with the surface of the cobalt removal solution, the electrolysis device enters an electric conduction state, and the polycrystalline diamond is only in surface contact with the liquid level.

Description

Mould for protecting hard alloy of PDC drill tooth from being corroded in cobalt removal process

Technical Field

The utility model relates to a PDC drill bit technical field, especially a protection PDC bores mould that tooth carbide is corroded in cobalt removal process.

Background

The PDC drill bit is widely used for exploration at home and abroad, plays an important role in accelerating the drilling of extremely soft to medium hard strata, and particularly provides a powerful support for improving the drilling speed, shortening the drilling period and reducing the drilling cost for the petroleum exploration industry in China. With the increase of deep wells, one of effective methods for improving the use efficiency of the drill bit is to improve the comprehensive performance of the cutting teeth, and the artificial polycrystalline diamond compact cobalt removal technology is an effective method capable of improving the working thermal stability of the compact so as to improve the use performance.

As shown in fig. 1, the conventional PDC bit 3 includes a cemented carbide portion 3a and a polycrystalline diamond portion 3 b. In the existing cobalt removal technology, cobalt removal is common by using a strong acid solution, the polycrystalline diamond part 3b of the PDC drill bit 3 is placed into the strong acid solution, the acid solution infiltrates into diamond particles to decompose and separate out metal cobalt, so that the cobalt removal purpose is achieved, and the comprehensive performance of the polycrystalline diamond part 3b of the PDC drill bit 3 is improved. However, it is desirable to avoid contact of the cemented carbide piece 3a with the acid solution when the acid solution contacts the polycrystalline diamond piece 3 b. When cobalt is removed, the polycrystalline diamond portion 3b is placed in a strong acid solution, and the joint between the cemented carbide portion 3a and the polycrystalline diamond portion 3b is corroded by the strong acid to a greater or lesser extent, which may affect the service life of the entire PDC drill bit 3.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to overcome prior art's shortcoming, provide a protection PDC bores tooth carbide and is being taken off the mould that the cobalt process was corroded.

The purpose of the utility model is realized through the following technical scheme:

the utility model provides a protection PDC bores mould that tooth carbide is corroded at cobalt removal process, includes the mould body, the inside of mould body is opened has the drill bit that has upper portion open-ended and is held the chamber, the bottom that the drill bit held the chamber is opened has a plurality of through-holes that run through mould body bottom surface, the upper end that the drill bit held the chamber is opened has big-end-up's conical surface groove, all coating has protective coating on the inner wall that the drill bit held the chamber and the bottom surface, and the drill bit holds the intracavity in is arranged in to the carbide part of PDC drill bit, and the polycrystalline diamond part of PDC drill bit is located the conical surface groove, and the degree of depth that the carbide.

Further, the thickness of the protective coating is 1-2 mm.

Further, a gap between the inner wall of the drill bit containing cavity and the outer wall of the hard alloy part is 400-600 microns.

Further, the inner wall of the bevel groove is also coated with a protective coating.

Further, the height of the bevel groove is equal to the height of the polycrystalline diamond portion.

Further, the die body is made of a polytetrafluoroethylene material.

Further, the roughness of the inner wall of the drill bit containing cavity is less than 1.5 microns.

The utility model has the advantages of it is following:

1. the utility model discloses a pack into the drill bit with the carbide part of PDC drill bit and hold the intracavity, ensure the drill bit simultaneously and hold the highly uniform of chamber highly and carbide part for the carbide part can be protected, in addition be provided with the conical surface groove in the upper end that the drill bit held the chamber, when polycrystalline diamond part with take off cobalt solution surface contact, electrolytic device gets into the electric on-state, and polycrystalline diamond and the only surface contact of liquid level, no longer deepen solution, in order to avoid solution pressure too big, the corruption blind area destroys.

2. The protective coating is coated in the drill bit cavity and is formed by mixing resin and polytetrafluoroethylene, so that the hydrophobic effect is achieved, a corrosion blind area is facilitated, and meanwhile, the polytetrafluoroethylene can reduce friction between the surface of the hard alloy part of the PDC drill bit and the inner surface of the drill bit cavity.

3. The height of the cone groove is equal to that of the polycrystalline diamond part, when the hard alloy part of the PDC drill bit is pressed into the drill bit containing cavity through the hydraulic machine, the pressure head of the hydraulic machine can be pressed on the upper end face of the die body, and the PDC drill bit is prevented from being continuously stressed and damaged after being pressed in place.

Drawings

FIG. 1 is a schematic structural view of a PDC drill bit of the present invention;

fig. 2 is a schematic top view of the mold of the present invention;

FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2;

FIG. 4 is a schematic view of the cross-sectional structure of the PDC drill bit after being loaded into the mold;

in the figure: the manufacturing method comprises the following steps of 1-a die body, 1 a-a drill bit containing cavity, 1 b-a through hole, 1 c-a conical bevel, 2-a protective coating, 3-a PDC drill bit, 3 a-a hard alloy part and 3 b-a polycrystalline diamond part.

Detailed Description

The invention will be further described with reference to the accompanying drawings, but the scope of the invention is not limited to the following description.

As shown in fig. 2 to 4, a mold for protecting PDC drill tooth cemented carbide from being corroded during cobalt removal includes a mold body 1, a drill bit containing cavity 1a having an upper opening is formed in the mold body 1, a plurality of through holes 1b penetrating through the bottom surface of the mold body 1 are formed in the bottom of the drill bit containing cavity 1a, a tapered groove 1c having a large upper end and a small lower end is formed in the upper end of the drill bit containing cavity 1a, protective coatings 2 are coated on the inner wall and the bottom surface of the drill bit containing cavity 1a, the protective coatings 2 are formed by mixing epoxy resin and polytetrafluoroethylene, the coatings have a hydrophobic effect, a cemented carbide part 3a of the PDC drill bit 3 is placed in the drill bit containing cavity 1a, a polycrystalline diamond part 3b of the PDC drill bit 3 is located in the tapered groove 1c, and the height of the cemented carbide part 3a is equal to the depth of the drill bit containing cavity 1. The hard alloy part 3a of the PDC drill bit 3 is arranged in the drill bit accommodating cavity 1a, the height of the drill bit accommodating cavity 1a is ensured to be consistent with the height of the hard alloy part 3a, the hard alloy part 3a can be protected, in addition, the conical bevel 1c is arranged at the upper end of the drill bit accommodating cavity 1a, when the polycrystalline diamond part 3b sinks into a cobalt removal solution, a corrosion blind area is formed between the inner surface of the small end of the conical bevel 1c and the polycrystalline diamond part 3b, and the hard alloy part 3a can be further prevented from being contacted with acid liquor.

Further, the thickness of the protective coating 2 is 1-2 mm.

Further, a gap between the inner wall of the drill bit accommodating cavity 1a and the outer wall of the hard alloy part 3a is 400-600 μm. When the hard alloy part 3a is pressed into the drill bit accommodating cavity 1a, the hard alloy part is not directly contacted with the inner wall of the drill bit accommodating cavity 1a, and the redundant protective coating 2 moves downwards under the extrusion of the hard alloy part 3a and finally flows out of the through hole 1 b.

Further, the inner wall of the bevel 1c is also coated with the protective coating 2, when the polycrystalline diamond portion 3b sinks into the cobalt removal solution, the cobalt removal solution on the protective coating 2 on the inner surface of the small end of the bevel 1c forms a hydrophobic angle of about 107 degrees, and forms a corrosion blind area with the polycrystalline diamond portion 3b, so that the hard alloy portion 3a can be further prevented from contacting with the acid solution.

Further, the height of the cone bevel 1c is equal to that of the polycrystalline diamond part 3b, when the hard alloy part 3a of the PDC drill bit 3 is pressed into the drill bit accommodating cavity 1a through a hydraulic machine, a pressure head of the hydraulic machine can be pressed on the upper end face of the die body 1, and the PDC drill bit 3 is prevented from being damaged due to continuous stress after being pressed in place.

Further, the die body 1 is made of polytetrafluoroethylene materials, can resist corrosion of strong acid, is easy to machine to form a flat surface, and is easy to demould.

Further, the roughness of the inner wall of the drill bit accommodating cavity 1a is less than 1.5 μm.

The working process of the utility model is as follows: before loading, firstly coating a layer of silicone oil on the surface of a hard alloy part 3a of a PDC drill bit 3, placing a die on a hydraulic press workbench, aligning the hard alloy part 3a of the PDC drill bit 3 to a drill bit containing cavity 1a, pressing down a pressure head, completely pressing the hard alloy part 3a of the PDC drill bit 3 into the drill bit containing cavity 1a, pressing the pressure head just on the upper end surface of the die body 1 at the moment, extruding the redundant protective coating 2 on the inner wall of the drill bit containing cavity 1a by the hard alloy part 3a of the PDC drill bit 3, flowing out of a through hole 1b, and sealing the through hole 1 b. After the PDC drill bit is loaded, the polycrystalline diamond part 3b of the PDC drill bit 3 is contacted with the cobalt removal solution, and the protection coating 2 can form a corrosion blind area with the cobalt removal solution, so that the cobalt removal solution can be prevented from contacting the hard alloy part 3a of the PDC drill bit 3, the cobalt removal solution only interacts with the polycrystalline diamond part 3b of the PDC drill bit 3, and the cobalt removal of the polycrystalline diamond part 3b of the PDC drill bit 3 is realized.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. The utility model provides a protection PDC bores mould that tooth carbide is corroded at cobalt removal process, includes mould body (1), its characterized in that: the utility model discloses a PDC drill bit, including mould body (1), drill bit chamber (1a) and drill bit chamber (3), the inside of mould body (1) is opened has drill bit chamber (1a) that has upper portion open-ended, the bottom of drill bit chamber (1a) is opened has a plurality of through-holes (1b) that run through mould body (1) bottom surface, the upper end of drill bit chamber (1a) is opened has big-end-up's conical surface groove (1c), all coat on the inner wall of drill bit chamber (1a) and the bottom surface and have protective coating (2), and in drill bit chamber (1a) was arranged in carbide part (3a) of PDC drill bit (3), polycrystalline diamond part (3b) of PDC drill bit (3) were located conical surface groove (1c), and the degree of depth that highly equals drill bit.

2. The mold for protecting the hard alloy of PDC drill teeth from being corroded in the cobalt removing process as claimed in claim 1, wherein: the thickness of the protective coating (2) is 1-2 mm.

3. The mold for protecting the hard alloy of PDC drill teeth from being corroded in the cobalt removing process as claimed in claim 2, wherein: the clearance between the inner wall of the drill bit containing cavity (1a) and the outer wall of the hard alloy part (3a) is 400-600 mu m.

4. The mold for protecting the hard alloy of PDC drill teeth from being corroded in the cobalt removing process as claimed in claim 1, wherein: the inner wall of the conical bevel (1c) is also coated with a protective coating (2).

5. The mold according to claim 3, for protecting PDC bit cemented carbide from erosion during cobalt removal, wherein: the height of the bevel groove (1c) is equal to the height of the polycrystalline diamond portion (3 b).

6. The mold for protecting the hard alloy of PDC drill teeth from being corroded in the cobalt removing process as claimed in claim 1, wherein: the die body (1) is made of polytetrafluoroethylene materials.

7. The mold for protecting the hard alloy of PDC drill teeth from being corroded in the cobalt removing process as claimed in claim 1, wherein: the roughness of the inner wall of the drill bit accommodating cavity (1a) is less than 1.5 mu m.