A PDC drill bit for oil field development

Abstract

The present invention provides a PDC drill bit for oilfield development, which relates to the field of oilfield exploitation. The PDC drill bit for oilfield development comprises a threaded portion, a drill body, a drill head, a central component, and a cutting component. The central component is arranged at the center of the drill head. The central component comprises a central column, and a central cutter is evenly and fixedly connected to the upper circumference of the central column. A drilling tip is arranged at the central connection of the central cutter. The cutting component comprises a blade body, and the blade body is provided with a first stage, a second stage, a third stage, and a fourth stage which gradually become lower from top to bottom. By setting up the central component, the cutting operation at the center can be carried out first, which plays a role of preliminary positioning, ensures the stability of the subsequent cutting operation of the cutting component, and has the function of breaking rocks, reducing the whole rock into small pieces of rock, and reducing the cutting resistance.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield exploitation, in particular to a PDC drill bit used for oilfield exploitation. Background Art

[0002] PDC drill bit, full name of polycrystalline diamond composite drill bit, is a kind of high-efficiency drill bit widely used in modern oil drilling. Its core part is made of polycrystalline diamond material, which has extremely high hardness and wear resistance and can effectively cope with various complex geological conditions.

[0003] In the existing technology, the PDC drill bit includes a blade, cutting teeth, and a nozzle hole. The contour line of the blade is arc-shaped, and the self-rotation of the cutting teeth is used to realize the function of drilling and mining. However, the cutting teeth at the end face opposite to the drilled layer are distributed in a plane, and their cutting depths are the same. The drill bit can only move in the drilling direction after the entire end face of the drill bit is completely cut. The drilling speed of the drill bit is slow, and the efficiency of the drilling operation is low. Summary of the invention

[0004] 1. Technical issues to be resolved

[0005] In view of the shortcomings of the prior art, the present invention provides a PDC drill bit for oil field development, which solves the problem that the cutting teeth have the same cutting depth, the drill bit can only move in the drilling direction after the entire end face of the drill bit is completely cut, the drilling speed of the drill bit is slow, and the efficiency of the drilling operation is low.

[0006] (II) Technical solution

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: A PDC drill bit for oil field development, comprising a threaded portion, a drill body portion, a drill head portion, and also comprising:

[0008] A center assembly, the center assembly is arranged at the center of the drill head, the center assembly comprises a center column, a center cutter is evenly fixedly connected to the upper circumference of the center column, and a drilling tip is arranged at the center connection of the center cutter;

[0009] A cutting assembly, wherein the cutting assembly is evenly arranged on the drill head, the cutting assembly is located outside the central assembly, and the cutting assembly includes a blade body, wherein the blade body is provided with a first stage, a second stage, a third stage, and a fourth stage which are gradually lowered from top to bottom, wherein an angle β2 between the first stage and the horizontal plane is 15°-20°, and an angle β1 between the third stage and the horizontal plane is 25°-45°, and a main cutting tooth, a secondary cutting tooth, and an anti-shrinkage tooth are evenly arranged on the cutting side of the blade body, wherein each secondary cutting tooth is located at a corresponding position of a gap between two adjacent main cutting teeth, and a gap value L1 between two adjacent main cutting teeth is greater than a distance value L2 between adjacent main cutting teeth and secondary cutting teeth;

[0010] A main drainage area and a secondary drainage area, wherein adjacent main drainage areas and secondary drainage areas are connected to each other, and the main drainage areas and secondary drainage areas are alternately arranged in a clockwise direction at the gap between adjacent cutting assemblies;

[0011] Nozzle hole, the nozzle hole is arranged in the drainage auxiliary area, a nozzle is installed in the nozzle hole, the nozzle generates water flow in the direction of liquid inlet at the center, and the angle ɑ2 between the liquid inlet direction and the center cutter in the drainage main area is 70°-74°. Through the central component set up, the cutting operation at the center can be carried out first, which plays a role in preliminary positioning, ensures the stability of the subsequent cutting operation of the cutting component, and has the function of breaking rocks, reducing the whole rock into small pieces of rock, and reducing the cutting resistance; through the cutting component set up, the rock can be cut in stages to achieve the effect of progressive drilling, ensuring smooth and stable drilling; the drainage main area and drainage auxiliary area set up are convenient for drainage and chip removal, and avoid mud packing of the drill bit.

[0012] Preferably, an expansion knife portion is provided on the upper portion of the center cutting knife, and the expansion knife portion is gradually expanded radially from top to bottom.

[0013] Preferably, a chip removal notch is provided at the upper part of the center column and between two adjacent center cutting knives, the chip removal notch is arranged in a fan shape, and an angle ɑ1 between the liquid inlet direction and the chip removal notch in the main liquid discharge area is 50°-54°.

[0014] Preferably, shackle grooves are symmetrically provided on the drill body.

[0015] Preferably, a chip removal portion is provided at one end of the blade body close to the central component, and at least one retention groove is provided on the cutting side of the blade body. Both ends of the retention groove are open, and the cross-sectional shape of the retention groove is an arc shape.

[0016] Preferably, the anti-shrinkage teeth are located at the vertical portion of the blade body.

[0017] Preferably, a reinforcement block is provided on the upper part of the central column and close to the drilling tip.

[0018] Preferably, the number of the nozzle holes and the center cutting knife is three, and the number of the blade bodies is six.

[0019] (III) Beneficial effects

[0020] The present invention provides a PDC drill bit for oil field development. It has the following beneficial effects:

[0021] 1. The present invention can first perform cutting operations at the center through the central component, which plays a role in preliminary positioning, ensures the stability of the subsequent cutting operations of the cutting components, and has the function of breaking rocks, reducing the entire rock into small pieces of rock, and reducing cutting resistance.

[0022] 2. The cutting assembly provided in the present invention can cut the rock in stages to achieve the effect of progressive drilling and ensure smooth and stable drilling.

[0023] 3. The present invention provides a main drainage area and a secondary drainage area to facilitate drainage and chip removal and avoid mud packing of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is an overall stereogram of the present invention;

[0025] Figure 2 is a perspective view of a cutting assembly of the present invention;

[0026] Figure 3 A three-dimensional view of the cutting assembly of the present invention from another perspective;

[0027] Figure 4 is a perspective view of the central component of the present invention;

[0028] Figure 5 A top view of the present invention;

[0029] Figure 6 is an angle schematic diagram of the blade body of the present invention;

[0030] Figure 7 It is a schematic diagram of a top view of the liquid inlet direction of the present invention;

[0031] Figure 8 It is a schematic diagram of the distribution of the main cutting teeth and the auxiliary chip teeth of the present invention.

[0032] Among them, 1. threaded part; 2. drill body; 3. drill head; 4. cutting assembly; 5. center assembly; 6. nozzle hole; 7. main drainage area; 8. auxiliary drainage area; 9. liquid inlet direction; 201. shackle groove; 401. first stage; 402. second stage; 403. third stage; 404. fourth stage; 405. anti-shrinkage tooth; 406. auxiliary cutting tooth; 407. main cutting tooth; 408. chip removal clearance part; 409. blade body; 410. retention groove; 501. center column; 502. chip removal notch; 503. center cutting tool; 504. expansion tool; 505. reinforcement block; 506. drilling tip. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. 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.

[0034] like Figure 1-Figure 8 As shown, an embodiment of the present invention is a PDC drill bit for oil field development, comprising a threaded portion 1, a drill body portion 2, and a drill head portion 3, wherein the drill body portion 2 is symmetrically provided with a shackle groove 201, and further comprising:

[0035] refer to Figure 1 The threaded portion 1 is used for connecting the drill bit, and the shackle groove 201 is used for disassembly and force bearing.

[0036] The center component 5 is arranged at the center of the drill head 3. The center component 5 includes a center column 501. A reinforcing block 505 is arranged on the upper part of the center column 501 and near the drilling tip 506. The upper circumference of the center column 501 is evenly and fixedly connected with a center cutter 503. There are three center cutters 503. The center joint of the center cutter 503 is provided with a drilling tip 506. The upper part of the center cutter 503 is provided with an expansion knife part 504. The expansion knife part 504 is gradually expanded radially from top to bottom. A chip removal notch 502 is arranged on the upper part of the center column 501 and between two adjacent center cutters 503. The chip removal notch 502 is arranged in a fan shape. The angle ɑ1 between the liquid inlet direction 9 and the chip removal notch 502 in the main liquid discharge area 7 is 50°-54°.

[0037] refer to Figure 5 , Figure 4The center column 501 is used to provide support and cutting height for the center cutter 503, the reinforcement block 505 is used to strengthen the force strength of the drilling tip 506 of the center cutter 503, the drilling tip 506 is used for drilling and crushing rocks, the expansion knife part 504 is used to expand the radius of the drilling hole during the center drilling process, increase the size of the center drilling hole, the chip removal notch 502 is used for chip removal, and facilitates the discharge of debris. The angle ɑ1 between the liquid inlet direction 9 and the chip removal notch 502 in the main drainage area 7 is 50°-54°. The chip removal notch 502 can guide the water flow flowing in the liquid inlet direction 9, so that the water flow is guided to the chip removal clearance part 408, thereby improving the cleaning effect of the debris and avoiding the debris from being blocked in the chip removal clearance part 408.

[0038] The cutting assembly 4 is evenly arranged on the circumference of the drill head 3, and the cutting assembly 4 is located on the outside of the central assembly 5. The cutting assembly 4 includes a blade body 409, and the number of the blade body 409 is six. The blade body 409 is provided with a chip removal portion 408 at one end close to the central assembly 5, and the blade body 409 is provided with at least one retention groove 410 on the cutting side. The retention groove 410 is open at both ends, and the cross-sectional shape of the retention groove 410 is an arc shape. The blade body 409 is provided with a first stage 401, a second stage 402, a third stage 403, and a third stage 404, which are gradually lowered from top to bottom. The fourth stage 404, the angle β2 between the first stage 401 and the horizontal plane is 15°-20°, the angle β1 between the third stage 403 and the horizontal plane is 25°-45°, the cutting side of the blade body 409 is evenly provided with main cutting teeth 407, auxiliary cutting teeth 406, and anti-shrinkage teeth 405, the anti-shrinkage teeth 405 are located at the vertical part of the blade body 409, each auxiliary cutting tooth 406 is located at the corresponding position of the gap between two adjacent main cutting teeth 407, and the gap value L1 between two adjacent main cutting teeth 407 is greater than the distance value L2 between the adjacent main cutting teeth 407 and auxiliary cutting teeth 406;

[0039] refer to Figure 2 , Figure 3The main cutting teeth 407 are used for cutting rock into small pieces. The auxiliary cutting teeth 406 are used for secondary cutting of the rock chips cut by the main cutting teeth 407 and for guiding the dispersion of the rock chips. They cooperate with the main cutting teeth 407 to form a good triangular cutting dispersion area. The gap value L1 between two adjacent main cutting teeth 407 is greater than the distance value L2 between the adjacent main cutting teeth 407 and the auxiliary cutting teeth 406, so that the rock chips are further cut and become smaller, and the rock chip particles are prevented from being too large, which is not conducive to the smooth removal of chips. The main cutting teeth 407 and the auxiliary cutting teeth 406 are not easy to adhere to the rock chips, so as to ensure the good cutting force. The anti-shrinkage teeth 405 are used to prevent the shrinkage, facilitate the assembly operation, and play a role in guiding and maintaining the overall stability. Among them, the first stage 401, the second stage 402, the third stage 403, The fourth stage 404 is designed to gradually become lower, so it will contact the rock in turn to form an increasing cutting surface. The angle β2 between the first stage 401 and the horizontal plane is 15°-20°, which is gentler than the angle β1 between the third stage 403 and the horizontal plane of 25°-45°. The main cutting tooth 407 has a smaller and finer tooth penetration, which has the advantages of stable drilling and smooth chip removal. The third stage 403 has a larger tooth penetration, and under the action of the inclination angle, a certain amount of downward force can be generated, which has the effect of accelerating the discharge of rock chips. Compared with the original planar cutting surface, it has the effects of greater cutting force, stable cutting and stable drilling; the retention groove 410 can retain a part of the water flow, reduce the heat of the blade body 409, and guide the flow direction of the water flow to play a role in impacting the rock chips.

[0040] The main drainage area 7 and the auxiliary drainage area 8 are connected to each other, and the main drainage area 7 and the auxiliary drainage area 8 are alternately arranged in a clockwise direction at the gap between the adjacent cutting assemblies 4;

[0041] refer to Figure 5 The main drainage area 7 and the auxiliary drainage area 8 are both used for drainage. However, the water flow pressure in the main drainage area 7 is greater than the water flow pressure in the auxiliary drainage area 8, forming a stable water flow direction. The straight water flow will provide a flushing function for the cutting tooth part of the cutting assembly 4. The reverse water flow blocked by the central column 501 will be dispersed and scattered, thereby increasing the flushing effect on the center and improving the smoothness of chip removal.

[0042] Nozzle hole 6, there are three nozzle holes 6, the nozzle holes 6 are arranged in the drainage sub-area 8, and a nozzle is installed in the nozzle hole 6. The nozzle generates a water flow toward the liquid inlet direction 9 at the center, and the angle ɑ2 between the liquid inlet direction 9 and the center cutting knife 503 in the drainage main area 7 is 70°-74°.

[0043] refer to Figure 5The nozzle generates a water flow in the liquid inlet direction 9 at the center for cleaning rock cuttings. The angle ɑ2 between the liquid inlet direction 9 and the center cutter 503 in the main discharge area 7 is 70°-74°, so that the water flow is guided to the retention tank 410, which is convenient for the discharge of the water flow. The water flow direction is stable, and the water flow can also play a role in cleaning the retention tank 410, facilitating the discharge of debris.

[0044] Working principle: During drilling operation, the center column 501 is used to provide support and cutting height for the center cutter 503, the reinforcement block 505 is used to strengthen the force strength of the drilling tip 506 of the center cutter 503, the drilling tip 506 is used to drill and crush rocks, the expansion knife part 504 is used to expand the radius of the drilling hole during the center drilling process, increase the size of the center drilling hole, the chip removal notch 502 is used for chip removal, and it is convenient for the debris to be discharged, the main cutting tooth 407 is used for cutting the rock chips, and cuts the rock into small pieces, the auxiliary cutting tooth 406 is used for secondary cutting of the stone chips cut by the main cutting tooth 407 and guides the stone chips to disperse, and cooperates with the main cutting tooth 407 to form a good triangular cutting dispersion area, the main cutting tooth 407 and the auxiliary cutting tooth 406 are not easy to adhere to the stone chips, so as to ensure the cutting force is intact, and the anti-shrinkage tooth 405 is used to prevent the diameter from shrinking, which is convenient for the assembly operation and plays a role in guiding and maintaining the overall stability. Among them, the first stage 4 01. The second stage 402, the third stage 403, and the fourth stage 404 are designed to gradually become lower, so they will contact the rock in turn to form an increasing cutting surface. Compared with the original planar cutting surface, it has the effects of greater cutting force, stable cutting, and stable drilling, and also reduces the discharge amount of rock chips to a certain extent, further ensuring the smooth discharge of chips. The retention groove 410 can retain a part of the water flow, reduce the heat of the blade body 409, and guide the flow direction of the water flow to impact the rock chips. The nozzle generates a water flow in the liquid inlet direction 9 toward the center, which can be discharged from the main drainage area 7 and the auxiliary drainage area 8. The water flow pressure in the main drainage area 7 is greater than the water flow pressure in the auxiliary drainage area 8, forming a stable water flow direction. The straight-flow water flow will provide a flushing function for the cutting tooth part of the cutting assembly 4, and the reverse water flow blocked by the center column 501 will be dispersed and scattered, increasing the flushing effect on the center and improving the smoothness of chip removal.

[0045] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A PDC drill bit for oilfield development, comprising a threaded portion (1), a drill body portion (2), and a drill head portion (3), characterized in that: Also includes: A center assembly (5), the center assembly (5) being arranged at the center of the drill head (3), the center assembly (5) comprising a center column (501), a center cutter (503) being evenly fixedly connected to the upper circumference of the center column (501), and a drilling tip (506) being arranged at the center joint of the center cutter (503); The cutting assembly (4) is evenly arranged on the circumference of the drill head (3), and the cutting assembly (4) is located outside the central assembly (5). The cutting assembly (4) comprises a blade body (409), and the blade body (409) is provided with a first stage (401), a second stage (402), a third stage (403), and a fourth stage (404) which are gradually lowered from top to bottom. The angle β2 between the first stage (401) and the horizontal plane is 15°-20°. The angle β1 between the third stage (403) and the horizontal plane is 25°-45°, and the cutting side of the blade body (409) is evenly provided with main cutting teeth (407), auxiliary cutting teeth (406), and anti-shrinkage teeth (405), each of the auxiliary cutting teeth (406) is located at the corresponding position of the gap between two adjacent main cutting teeth (407), and the gap value L1 between two adjacent main cutting teeth (407) is greater than the distance value L2 between the adjacent main cutting teeth (407) and the auxiliary cutting teeth (406); A main drainage area (7) and a secondary drainage area (8), wherein adjacent main drainage areas (7) and secondary drainage areas (8) are connected to each other, and the main drainage areas (7) and secondary drainage areas (8) are alternately arranged in a clockwise direction at the gap between adjacent cutting assemblies (4); A nozzle hole (6), wherein the nozzle hole (6) is arranged in the drainage sub-area (8), a nozzle is installed in the nozzle hole (6), and the nozzle generates a water flow toward a liquid inlet direction (9) at the center, and an angle ɑ2 between the liquid inlet direction (9) and a central cutting blade (503) in the drainage main area (7) is 70°-74°.

2. A PDC drill bit for oil field development according to claim 1, characterized in that: An expansion knife portion (504) is provided on the upper portion of the central cutting knife (503), and the expansion knife portion (504) is gradually expanded in a radial direction from top to bottom.

3. A PDC drill bit for oil field development according to claim 1 or 2, characterized in that: A chip removal notch (502) is provided at the upper part of the central column (501) and between two adjacent central cutting tools (503). The chip removal notch (502) is arranged in a fan shape, and an angle ɑ1 between the liquid inlet direction (9) and the chip removal notch (502) in the liquid discharge main area (7) is 50°-54°.

4. A PDC drill bit for oil field development according to claim 1, characterized in that: The drill bit body (2) is symmetrically provided with shackle grooves (201).

5. The PDC drill bit for oil field development according to claim 1, characterized in that: A chip removal portion (408) is provided at one end of the blade body (409) close to the central component (5), and at least one retention groove (410) is provided on a side of the blade body (409) facing the cutting edge. Both ends of the retention groove (410) are open, and the cross-section of the retention groove (410) is in the shape of an arc.

6. The PDC drill bit for oil field development according to claim 1, characterized in that: The anti-shrinkage teeth (405) are located at the vertical portion of the blade body (409).

7. The PDC drill bit for oil field development according to claim 1, characterized in that: A reinforcement block (505) is provided at the upper portion of the central column (501) and close to the drilling tip (506).

8. The PDC drill bit for oil field development according to claim 1, characterized in that: The number of the nozzle holes (6) and the center cutting blade (503) is three, and the number of the blade body (409) is six.

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