Drill bit

Abstract

The invention provides a drill bit which comprises attack teeth and cutting teeth, in the cutting process, the cutting teeth conduct cutting firstly, the temperature of the drill bit can be increased, the attack teeth move to protrude out of the cutting teeth to replace the cutting teeth to conduct cutting, the cutting teeth and the drill bit are cooled together after cutting is stopped, the attack teeth retract to the original position, and cutting continues to be conducted through the cutting teeth. The cutting teeth and the attacking teeth are used for alternately breaking rocks, so that in the process of drilling a deep, compact and difficult-to-drill stratum, the rock breaking efficiency is improved, premature failure of the cutting teeth caused by thermal wear is avoided, and wear caused by continuous rock breaking of the cutting teeth and the attacking teeth at the same time is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling equipment, in particular to a drill bit. Background Art

[0002] With the development of drilling technology, drill bits have been widely used in oil fields, mines and engineering drilling. Improving drill bit design plays a vital role in reducing drilling costs. An important aspect of drill bit improvement is the optimization of drill bit design.

[0003] The drilling elements of existing PDC drill bits are usually cylindrical cutting teeth made of polycrystalline diamond material, which are suitable for drilling medium-hard rock formations and have a large cutting depth. However, in the process of drilling hard rock, cutting is difficult, and due to the large shear resistance, the rotational torque and torque fluctuation of the drill bit are relatively large, resulting in low rock breaking efficiency and serious impact damage to the cutting teeth. At the same time, during high-speed drilling, the cutting temperature generated by the intense friction with the rock will be converted into friction heat, resulting in uneven thermal expansion of the cutting teeth, resulting in large thermal stress inside the cutting teeth, causing deformation of the cutting teeth and aggravated thermal wear, thereby reducing the performance of the cutting teeth.

[0004] The conical teeth of existing PDC drill bits break rocks by plowing, which can form a high concentrated load on the rock formation, causing cracks to occur in the rock. For hard rock formations, it can easily destroy the rock strength, but its penetration is small. Using only conical teeth to break rocks has a slow advancement speed, and the attack end is easily worn out after plowing hard rock formations for a long time.

[0005] The prior art has drill bits that combine PDC cylindrical cutting teeth and conical cutting teeth, but since the cutting end of the cylindrical cutting teeth and the attack end of the conical cutting teeth are at the same height, during the rock breaking process, both will act on the rock at the same time, resulting in the inability to fully utilize the plowing advantage of the conical cutting teeth. If the conical cutting teeth protrude from the cylindrical cutting teeth, the attack end of the conical cutting teeth will wear out and fail prematurely, which will also reduce the rock breaking efficiency. Summary of the invention

[0006] One object of the present invention is to provide a drill bit that breaks rock alternately by cutting teeth and attack teeth, so as to improve the rock breaking efficiency during drilling into difficult-to-drill formations, avoid premature failure of the cutting teeth due to thermal wear, and reduce the wear caused by the cutting teeth and attack teeth breaking rock simultaneously and continuously.

[0007] According to the present invention, a drill bit includes an attack tooth and a cutting tooth. During the cutting process, the cutting tooth cuts first and can heat up the drill bit. The attack tooth moves to protrude from the cutting tooth to replace the cutting tooth. After the cutting tooth stops cutting, the cutting tooth cools down together with the drill bit. The attack tooth retracts to its original position, and the cutting tooth continues cutting.

[0008] In a preferred embodiment, it also includes a thermally expandable component connected to the attack tooth, which can expand after reaching a set temperature so that the attack tooth moves to protrude from the cutting tooth, and can contract after dropping below a set temperature so that the attack tooth retracts to its original position.

[0009] In a preferred embodiment, the thermal expansion member is a memory alloy element.

[0010] In a preferred embodiment, the attack tooth includes an attack tooth body and a receiving portion for receiving and fixing the attack tooth body, the attack tooth body has an attack end, the first end of the receiving portion is connected to the thermal expansion member, and the second end of the receiving portion is connected to the end of the attack tooth body away from the attack end.

[0011] In a preferred embodiment, a base is further provided on the blade, a cavity is provided inside the base, and the thermal expansion member is provided in the cavity.

[0012] In a preferred embodiment, a sealing ring is further provided on the base and the sealing ring is sleeved on the accommodating portion to prevent the solid phase in the bottom hole mud from entering the interior of the chamber through the attack tooth.

[0013] In a preferred embodiment, an elastic member is further provided on the base, and the elastic member is sleeved on the outer periphery of the accommodating portion. The drill bit also includes a pressure cover, which is fixed to the base and pressed onto the elastic member to generate a preload.

[0014] In a preferred embodiment, a retaining ring is provided on the upper surface of the gland.

[0015] In a preferred embodiment, the drill bit further comprises a drill bit rigid body, which is constructed as a cylindrical structure and has a hydraulic flow channel inside thereof for allowing drilling fluid to enter the bottom of the well.

[0016] In a preferred embodiment, the drill bit further comprises a nozzle disposed at the bottom of the drill bit, and the nozzle is connected to the outlet end of the hydraulic channel.

[0017] The drill bit of the present invention comprises attack teeth and cutting teeth, and during the cutting process, the cutting teeth cut first and can heat up the drill bit, the attack teeth move to protrude from the cutting teeth to replace the cutting teeth, the cutting teeth cool down together with the drill bit after stopping cutting, the attack teeth retract to their original positions, and the cutting teeth continue cutting. The advantages of the cutting teeth and the attack teeth are combined, and during the process of drilling into deep, dense and difficult-to-drill formations, the cutting teeth are worn due to continuous high-pressure drilling, causing the drill bit to heat up rapidly, thereby causing the attack teeth to move to protrude from the cutting teeth, replacing the cutting teeth to perform ultra-high concentrated load plowing and rock breaking on difficult-to-drill formations. , causing cracks to occur in the hard rock and reducing the local strength of the hard rock. The cutting teeth are separated from the rock and cooled down together with the drill bit under the action of the drilling fluid, so that the attack teeth retract to their original position. Since the hard rock has been cracked and its strength has been reduced, the cutting teeth can then easily cut in and continue to advance to break the rock, thereby increasing the rock breaking speed and avoiding premature failure of the cutting teeth due to thermal wear, effectively protecting the cutting teeth. Compared with the existing drill bits in which both the conical teeth and the cutting teeth are involved in rock breaking, the rock is broken alternately by the cutting teeth and the attack teeth, thereby reducing the wear caused by the continuous rock breaking of the cutting teeth and the attack teeth at the same time.

[0018] The present invention includes a thermally expandable component connected to the attack tooth, and the thermally expandable component can expand after reaching a set temperature so that the attack tooth moves to protrude from the cutting tooth, and can also contract after the temperature is reduced to below the set temperature so that the attack tooth retracts to its original position. The continuous high-pressure drilling wear of the cutting tooth will cause the drill bit to heat up rapidly. The thermally expandable component can extend to push the attack tooth to protrude from the cutting tooth to replace the cutting tooth to break the rock. It can also retract the attack tooth to its original position after the cutting tooth is separated from the rock formation and the drill bit is cooled down, thereby controlling the attack tooth and the cutting tooth to break the rock alternately, effectively protecting the cutting tooth and the attack tooth, and reducing the wear caused by the cutting tooth and the attack tooth breaking the rock continuously at the same time.

[0019] The present invention arranges the cutting teeth, thermal expansion parts and attack teeth on the blade. On the one hand, during drilling into deep, dense and difficult-to-drill formations, the cutting teeth quickly heat up due to continuous high-pressure drilling wear, and rapid heat transfer can be achieved between the blade and the thermal expansion parts, so that the thermal expansion parts can be quickly heated up, so that the attack teeth move to protrude from the cutting teeth, replacing the cutting teeth to perform ultra-high concentrated load plowing and rock breaking on difficult-to-drill formations. On the other hand, by arranging the attack teeth, expansion parts and attack teeth on the blade, it is convenient to realize alternating rock breaking by the cutting teeth and the attack teeth.

[0020] The present invention further provides a base on the blade, a chamber inside the base and a thermal expansion component in the chamber. On the one hand, the cutting teeth and the attack teeth can be separated by providing the base to avoid mutual influence during drilling. On the other hand, the thermal expansion component can be effectively protected by providing the chamber.

[0021] The present invention has an elastic part on the base and the elastic part is sleeved on the outer periphery of the accommodating part. The drill bit also includes a pressure cover and the pressure cover is fixed to the base and pressed on the elastic part to generate a pre-tightening force. After the thermal expansion part is cooled to below the set temperature along with the drill bit, during the retraction process of the thermal expansion part, the elastic part can apply elastic force to the accommodating part to help it retract to its original position. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram schematically shows the overall structure of a drill bit according to the present invention;

[0023] Figure 2 The structural diagram of the base body according to the present invention is schematically shown.

[0024] In the present application, all drawings are schematic drawings, which are only used to illustrate the principles of the present invention and are not drawn according to the actual scale. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0026] In the description of the present invention, it is necessary to understand that the orientations or positional relationships indicated by terms such as "bottom", "inside", "convex", "far away" and "outside" are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0027] In the present invention, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral or abutting connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] like Figure 1 and Figure 2As shown, the drill bit 100 of the present invention includes an attack tooth 16 and a cutting tooth 5. When the rock formation is not cut, the cutting tooth 5 protrudes from the attack tooth 16, that is, the cutting end of the cutting tooth 5 is closer to the rock formation than the cutting end of the attack tooth 16. During the cutting process, the cutting tooth 5 first contacts with the rock formation and cuts the rock formation. Due to the continuous high-pressure drilling of the friction formation during the cutting process, the temperature of the drill bit 100 rises rapidly, so that the attack tooth 16 of the drill bit 100 can move to protrude from the cutting tooth 5 and replace the cutting tooth 5 for cutting. The attack tooth 16 generates microcracks on the hard and dense rock, and the cutting tooth 5 stops cutting due to being out of contact with the rock formation. After the cutting tooth 5 stops cutting, the cutting tooth 5 and the drill bit 100 are quickly cooled down together under the action of the drilling fluid, so that the attack tooth 16 retracts to the original position, and the cutting tooth 5 protrudes from the attack tooth 16 and the cutting process is continued by the cutting tooth 5. The attack tooth 16 can be a specific strong attack tooth, for example, a conical tooth.

[0029] The drill bit 100 of the present invention includes an attack tooth 16 and a cutting tooth 5. During the cutting process, the cutting tooth 5 cuts first and can heat up the drill bit 100. The attack tooth 16 moves to protrude from the cutting tooth 5 to replace the cutting tooth 5. After the cutting tooth 100 stops cutting, the temperature is reduced together with the drill bit 100. The attack tooth 16 retracts to its original position, and the cutting tooth 5 continues to cut. The advantages of the cutting tooth 5 and the attack tooth 16 are combined. During the drilling process of deep, dense and difficult-to-drill formations, the cutting tooth 5 is worn due to continuous high-pressure drilling, causing the drill bit 100 to heat up quickly, thereby causing the attack tooth 16 to move to protrude from the cutting tooth 5 to replace the cutting tooth 5 to perform ultra-drilling on the difficult-to-drill formation. The high concentrated load plows and breaks the rock, causing cracks in the hard rock and reducing the local strength of the hard rock. The cutting teeth 5 are separated from the rock and rapidly cool down together with the drill bit 100 under the action of the drilling fluid, so that the attack teeth 16 retract to their original position. Since the hard rock has been cracked and its strength has been reduced, the cutting teeth 5 can then easily cut in and continue to advance to break the rock, thereby increasing the rock breaking speed and avoiding premature failure of the cutting teeth 5 due to thermal wear, effectively protecting the cutting teeth 5. Compared with the existing drill bits in which both the conical teeth and the cutting teeth are involved in rock breaking, the cutting teeth 5 and the attack teeth 16 are used to break the rock alternately, thereby reducing the wear caused by the cutting teeth 5 and the attack teeth 16 breaking the rock simultaneously.

[0030] In one or more embodiments, the attack teeth 16 and the cutting teeth 5 are arranged side by side.

[0031] In one or more embodiments, the drill bit 100 of the present invention further includes a thermal expansion member 14 connected to the end of the attack tooth 16 away from the cutting end. During the process of drilling deep, dense and difficult-to-drill formations, the cutting tooth 5 continuously rubs the formation due to continuous high-pressure drilling, causing the drill bit 100 to heat up rapidly. After the thermal expansion member 14 heats up to a set temperature with the drill bit 100, the thermal expansion member 14 can extend after reaching the set temperature to push the attack tooth 16 to move to protrude from the cutting tooth 5, so as to replace the cutting tooth 5 to plow and break the rock in the difficult-to-drill formation with an ultra-high concentrated load. The cutting tooth 5 is separated from the rock and cooled down, and is cooled down together with the drill bit 100 under the action of the drilling fluid. The thermal expansion member 14 cools down to below the set temperature with the drill bit 100, so that the attack tooth 16 retracts to its original position. "Set temperature" refers to the temperature that the thermal expansion member 14 can reach and respond to stretch and deform during the cutting process of the cutting tooth 5.

[0032] It should be noted that when drilling in easy-to-drill formations of medium or lower hardness, the cutting teeth 5 can easily cut the formations, the cutting teeth 5 will not cause the drill bit 100 to heat up rapidly due to continuous high-pressure drilling friction, the thermal expansion component 14 will not be able to reach the set temperature and expand, and the attack teeth 16 will not move to protrude from the cutting teeth 5 and plow the formation, thereby effectively protecting the attack teeth 16.

[0033] The present invention includes a thermally expandable component 14 connected to the attack tooth 16, and the thermally expandable component 14 can expand after reaching a set temperature, so that the attack tooth 16 moves to protrude from the cutting tooth 5, and can automatically shrink after the temperature is reduced to below the set temperature, so that the attack tooth 16 retracts to its original position. The continuous high-pressure drilling and continuous friction of the cutting tooth 5 on the rock will cause the drill bit 100 to heat up rapidly, and then the temperature of the thermally expandable component 14 increases, and the attack tooth 16 can be pushed out to protrude from the cutting tooth 5 by expansion, so as to replace the cutting tooth 5 to break the rock. It can also be retracted to retract the attack tooth 16 to its original position after the cutting tooth 5 is separated from the rock formation and the drill bit 100 is cooled down, so that the attack tooth 16 can be controlled to break the rock alternately with the cutting tooth 5, effectively protecting the cutting tooth 5 and the attack tooth 16, and reducing the wear caused by the cutting tooth 5 and the attack tooth 16 breaking the rock simultaneously.

[0034] In one or more embodiments, the thermal expansion member 14 is a memory alloy element, which is optionally configured in a columnar shape. The memory alloy element has a two-way memory property, which can be expanded after reaching a set temperature to push the attack tooth 16 to move to protrude from the cutting tooth 5, and can be contracted after the drill bit 100 is cooled to below a set temperature, so that the attack tooth 16 retracts to its original position, thereby facilitating the control of the attack tooth 16 and the cutting tooth 5 to alternately break the rock, and effectively protecting the cutting tooth 5 and the attack tooth 16.

[0035] In one or more embodiments, the attack tooth 16 includes an attack tooth body 161 and a receiving portion 162 for receiving and fixing the attack tooth body 161, the attack tooth body 161 having an attack end, a first end of the receiving portion 162 being connected to the thermal expansion member 14, and a second end of the receiving portion 162 being connected to an end of the attack tooth body 161 away from the attack end. The second end of the receiving portion 162 is configured in a cylindrical shape, and the first end is configured in a cone shape.

[0036] In one or more embodiments, the drill bit 100 described in the present invention further includes a blade wing 3 , and the cutting teeth 5 , the thermal expansion member 14 and the attack teeth 16 are all arranged on the blade wing 3 .

[0037] The present invention includes a blade wing 3, and the cutting teeth 5, the thermal expansion member 14 and the attack teeth 16 are all arranged on the blade wing 3. On the one hand, during the drilling of deep, dense and difficult-to-drill formations, the cutting teeth 5 are rapidly heated up due to continuous friction with the hard rock during continuous high-pressure drilling. Rapid heat transfer can be achieved between the blade wing 3 and the thermal expansion member 14, so that the thermal expansion member 14 can be rapidly heated up, so that the attack teeth 16 are moved to protrude from the cutting teeth 5, so as to replace the cutting teeth 5 to perform ultra-high concentrated load plowing and rock breaking on the difficult-to-drill formations; on the other hand, by arranging the attack teeth 16, the expansion member 14 and the attack teeth 16 on the blade wing 3, it is convenient to realize the alternating rock breaking of the cutting teeth 5 and the attack teeth 16.

[0038] In one or more embodiments, a base 8 is further provided on the blade 3 , the base 8 has a chamber 15 inside, and a thermal expansion member 14 is provided in the chamber 15 .

[0039] In the present invention, a base 8 is further provided on the blade 3, a chamber 15 is provided inside the base 8, and a thermal expansion component 14 is provided in the chamber 15. On the one hand, the base 8 can separate the cutting teeth 5 and the attack teeth 16 to avoid mutual influence during the drilling process. On the other hand, the chamber 15 can effectively protect the thermal expansion component 14.

[0040] In one or more embodiments, the base 8 is further provided with a sealing ring 11 and the sealing ring 11 is sleeved on the outer periphery of the accommodating portion 162 to prevent the solid phase in the bottom hole mud from entering the chamber 15 through the attack tooth 16, thereby preventing the mud from affecting the movement of the attack tooth 16.

[0041] In one or more embodiments, an elastic member 13 is further provided on the base 8, and the elastic member 13 is sleeved on the outer periphery of the accommodating portion 162. The drill bit 100 of the present invention further includes a gland 10, which is fixed to the base 8 through threads and pressed on the elastic member 13 to generate a preload. The elastic member 13 may be a compression spring.

[0042] In the present invention, an elastic member 13 is further provided on the base 8 and the elastic member 13 is sleeved on the outer periphery of the accommodating portion 162, and the drill bit 100 also includes a pressure cover 10 and the pressure cover 10 is fixed to the base 8 and pressed on the elastic member 13 to generate a pre-tightening force. After the thermal expansion member 14 is cooled to below the set temperature along with the drill bit 100, during the retraction process of the thermal expansion member 14, the elastic member 13 can apply elastic force to the accommodating portion 162 to help it retract to its original position.

[0043] In one or more embodiments, a retaining ring 9 is disposed on the upper surface of the gland 10 to prevent the gland 10 from loosening and falling off due to vibration of the drill bit during downhole drilling.

[0044] In one or more embodiments, the drill bit 100 described in the present invention further includes a drill bit rigid body 1, which is constructed as a cylindrical structure with a hydraulic flow channel 2 reserved therein for allowing drilling fluid to enter the bottom of the well.

[0045] In one or more embodiments, the drill bit 100 of the present invention further comprises a nozzle 4 disposed at the bottom of the drill bit 100, the nozzle 4 being connected to the outlet end of the hydraulic channel 2 to generate a jet of fluid to flush the bottom of the well. The upper end of the drill bit rigid body 1 can be connected to the drilling tool via a threaded member.

[0046] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A drill bit, comprising an attack tooth and a cutting tooth. During the cutting process, the cutting tooth cuts first and can heat up the drill bit. The attack tooth moves to protrude from the cutting tooth to replace the cutting tooth. After the cutting stops, the cutting tooth cools down together with the drill bit. The attack tooth retracts to its original position, and the cutting tooth continues cutting.

2. The drill bit according to claim 1, characterized in that It also includes a thermal expansion component connected to the attack tooth, which can expand after reaching a set temperature so that the attack tooth moves to protrude from the cutting tooth, and can shrink after dropping below a set temperature so that the attack tooth retracts to its original position.

3. The drill bit according to claim 2, characterized in that The thermal expansion component adopts a memory alloy element.

4. The drill bit according to claim 2, characterized in that The attack tooth includes an attack tooth body and a receiving portion for receiving and fixing the attack tooth body, the attack tooth body has an attack end, the first end of the receiving portion is connected to the thermal expansion component, and the second end of the receiving portion is connected to the end of the attack tooth body away from the attack end.

5. The drill bit according to claim 4, characterized in that The blade wing is also provided with a base body, the inside of which is provided with a chamber, and the heat-expandable component, the attack tooth and its accessories are arranged in the chamber.

6. The drill bit according to claim 5, characterized in that A sealing ring is also provided on the base and is sleeved on the accommodating portion to prevent the solid phase in the bottom hole mud from entering the chamber through the attack tooth.

7. The drill bit according to claim 5, characterized in that An elastic member is also provided on the base, and the elastic member is sleeved on the outer periphery of the accommodating portion. The drill bit also includes a pressure cover, which is fixed to the base and pressed on the elastic member to generate a pre-tightening force.

8. The drill bit according to claim 7, characterized in that A retaining ring is arranged on the upper surface of the gland.

9. The drill bit according to claim 1, characterized in that The drill bit rigid body is also included. The drill bit rigid body is constructed into a cylindrical structure and has a hydraulic flow channel inside to allow drilling fluid to enter the bottom of the well.

10. The drill bit according to claim 9, characterized in that It also includes a nozzle arranged at the bottom of the drill bit, and the nozzle is connected to the outlet end of the hydraulic flow channel.

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