Fracture blade type PDC drill bit

Abstract

The invention discloses a fractured blade type PDC drill bit which comprises a base body, a first blade set, a second blade set and a hydraulic structure, the base body comprises a liquid flow channel, and the liquid flow channel is used for providing a flowing channel for drilling fluid; the first cutter wing set comprises at least two first cutter wings, and a chip removal area is formed by the area defined by every two adjacent first cutter wings and the base body. The second cutter wing group comprises at least two second cutter wings, and the at least two second cutter wings and the at least two first cutter wings are oppositely arranged in a staggered mode in the circumferential direction of the base body; the hydraulic structure is arranged in at least one chip removal area and comprises a water hole communicated with the liquid flow channel. The at least two second blades and the at least two first blades are oppositely arranged in the circumferential direction of the base body in a staggered mode, so that the single drill bit is suitable for soft to medium-hard strata, drilling fluid in the liquid flow channel is guided into a chip removal area through the water holes, discharging of rock debris is accelerated, and it is prevented that the rock debris blocks the drill bit flow channel to cause bit balling; and the rock breaking efficiency of the drill bit is prevented from being influenced by repeated cutting and abrasion of cutting elements.

Description

Technical Field

[0001] The present application belongs to the technical field of drilling equipment, and in particular relates to a fractured blade type PDC drill bit. Background Art

[0002] In the drilling construction of oil and gas fields, PDC (Polycrystalline Diamond Compact) drill bits are widely used as the main bottom hole rock breaking tools. PDC drill bits rely on cutting action to break the formation, the rock destruction volume is large, and the rock breaking efficiency is high, but the conventional straight or streamlined flow channel makes it very easy for large pieces of rock cuttings to accumulate on the drill bit crown and the bottom of the well. The rock cuttings will not only block the drill bit flow channel and cause the drill bit to be mud-packed, but the repeated circulation of the rock cuttings will lead to the consumption of the bottom hole hydraulic energy. The repeated breaking of rock cuttings by the drill bit will also cause the drill bit cutting teeth to wear rapidly, reducing the drill bit's rock breaking efficiency.

[0003] Therefore, it is an urgent problem that the industry needs to solve to reasonably optimize the hydraulic structure of the drill bit, improve the utilization rate of the drill bit's hydraulic energy, and enhance the drill bit's hydraulic rock carrying and bottom hole cleaning function in soft to hard formations, thereby improving the drill bit's rock breaking efficiency and extending its service life. Summary of the invention

[0004] In order to solve the technical problems in the prior art that the conventional straight or streamlined flow channels make it very easy for large rock cuttings to accumulate on the drill bit crown and the bottom of the well, blocking the drill bit flow channel and causing mud packing on the drill bit, and that repeated crushing of rock cuttings by the drill bit will also cause rapid wear of the drill bit cutting teeth and reduce the rock breaking efficiency of the drill bit, the present application provides a fractured blade type PDC drill bit.

[0005] The present application provides a fractured blade type PDC drill bit, comprising a base body, a first blade group, a second blade group and a hydraulic structure, wherein:

[0006] The substrate includes a liquid flow channel, and the liquid flow channel is used to provide a flow channel for drilling fluid;

[0007] The first blade group includes at least two first blades, the first blades extend outward from the center of the end of the base, and the area enclosed by two adjacent first blades and the base forms a chip removal area;

[0008] The second blade group includes at least two second blades, the second blades extend outward from the outer edge of the end of the base, and the height of the second blade is greater than the height of the first blade, and at least two of the second blades and at least two of the first blades are arranged in a staggered manner relative to each other along the circumference of the base;

[0009] The hydraulic structure is arranged in at least one of the chip removal areas, and the hydraulic structure at least comprises a water eye, and the water eye is connected to the liquid flow channel.

[0010] In some optional embodiments, the angles between any two adjacent first blades are the same.

[0011] In some optional embodiments, the first blade wing is arranged parallel to the radial direction of the base, and the first blade wing is a straight blade wing or a spiral blade wing.

[0012] In some optional embodiments, the first blade wing includes a first side surface and a second side surface, and the first side surface and the second side surface are arranged opposite to each other along the length direction of the first blade wing;

[0013] A plurality of first cutting elements are arranged on the first blade, and the first cutting elements include a first tooth support and a first polycrystalline diamond composite sheet. The plurality of first tooth supports are linearly arranged on the first side surface, and the first polycrystalline diamond composite sheet is connected to an end of the first tooth support away from the second side surface.

[0014] In some optional embodiments, the first tooth support and the first blade wing are integrally formed.

[0015] In some optional embodiments, the sum of the number of the first blade wings and the number of the second blade wings is at least five, and at least one second blade wing is arranged between any two adjacent first blade wings.

[0016] In some optional embodiments, the second blade wing includes a third side surface and a fourth side surface, and the third side surface and the fourth side surface are arranged opposite to each other along the length direction of the second blade wing;

[0017] A plurality of second cutting elements are arranged on the second blade, and the second cutting elements include a second tooth support and a second polycrystalline diamond composite sheet. The plurality of second tooth supports are linearly arranged on the third side surface, and the second polycrystalline diamond composite sheet is connected to an end of the second tooth support away from the fourth side surface, and the size of the second polycrystalline diamond composite sheet is larger than that of the first polycrystalline diamond composite sheet.

[0018] In some optional embodiments, a plurality of the first cutting elements arranged linearly are further disposed on the third side surface, and the plurality of the first cutting elements are parallel to the plurality of the second cutting elements.

[0019] In some optional embodiments, the hydraulic structure further comprises a nozzle, wherein the nozzle is connected to the water eye and faces the chip removal area.

[0020] In some optional embodiments, a connecting structure is provided at one end of the base body away from the first blade group, and the connecting structure is used to connect to a drill pipe; and a diameter protection structure is provided on the outer wall of the base body near the second blade group.

[0021] The fractured blade PDC drill bit provided according to one or more embodiments of the present application has the following beneficial effects compared with the prior art:

[0022] By arranging at least two of the second blades and at least two of the first blades relatively staggered along the circumference of the base, when the drill bit contacts a softer formation, the second cutting element on the second blade acts first, and the second cutting element with a large size penetrates deeper into the bottom layer, thereby achieving a higher mechanical drilling speed; when the drill bit contacts a harder formation, it is only necessary to appropriately increase the drilling pressure to make the first blade contact the hard formation to participate in rock breaking and cutting, so that a single drill bit is suitable for drilling operations in soft to medium-hard formations, avoiding frequent drilling, strong adaptability and simple structure. At the same time, during the drilling operation, the water eye introduces the drilling fluid in the liquid flow channel into the chip removal area, eliminates the retention and reflux areas, accelerates the discharge of cuttings from the chip removal area, prevents the cuttings from clogging the drill bit flow channel and causing mud packing of the drill bit, and avoids repeated cutting and rapid wear of the cutting elements that affect the rock breaking efficiency of the drill bit. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure shows a right side view of a fractured blade type PDC drill bit in an embodiment of the present invention;

[0024] Figure 2 The embodiment of the present invention is shown Figure 1 AA section view.

[0025] Explanation of the reference numerals: 1-base, 11-liquid flow channel, 12-connecting structure, 121-connecting thread, 13-diameter protection structure; 2-first blade, 21-first side, 22-second side, 23-first cutting element, 231-first tooth support, 232-first polycrystalline diamond composite sheet; 3-second blade, 31-third side, 32-fourth side, 33-second cutting element, 331-second tooth support, 332-second polycrystalline diamond composite sheet; 4-chip removal area; 5-hydraulic structure, 51-water eye. DETAILED DESCRIPTION

[0026] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0027] Reference Figure 1 and Figure 2As shown, an embodiment of the present application provides a fractured blade type PDC drill bit, comprising a base body 1, a first blade group, a second blade group and a hydraulic structure 5, wherein:

[0028] The substrate 1 includes a liquid flow channel 11, and the liquid flow channel 11 is used to provide a flow channel for the drilling fluid; the substrate 1 can be made of hard alloy or other suitable materials to form a roughly cylindrical rotating body, and a non-through liquid flow channel 11 whose center line coincides with the center line of the substrate 1 is opened from the bottom of the substrate 1 to the inside of the substrate 1, and the liquid flow channel 11 is used to provide a flow channel for the drilling fluid. When drilling, a mud pump can be used to pump the drilling fluid into the liquid flow channel 11;

[0029] The first blade group includes at least two first blades 2, the first blades 2 extending outward from the center of the end of the base 1, the first blades 2 are generally in the shape of long strips and protrude from the surface of the base 1, and the area enclosed by two adjacent first blades 2 and the base 1 forms a chip removal area 4;

[0030] The second blade group includes at least two second blades 3, the second blades 3 extend outward from the outer edge of the end of the base 1, the second blades 3 are generally in the shape of a long strip and protrude from the surface of the base 1, and the height of the second blade 3 is greater than the height of the first blade 2, and at least two of the second blades 3 and at least two of the first blades 2 are arranged in a staggered manner relative to each other along the circumference of the base 1;

[0031] The hydraulic structure 5 is disposed in at least one of the chip removal areas 4 . The hydraulic structure 5 at least includes a water eye 51 . The water eye 51 is connected to the liquid flow channel 11 .

[0032] The fractured blade type PDC drill bit provided in the present embodiment is arranged in a relatively staggered manner along the circumference of the base body 1 by at least two of the second blades 3 and at least two of the first blades 2. When the drill bit contacts a softer formation, the second cutting element 33 on the second blade 3 acts first, and the large-sized second cutting element 33 penetrates deeper into the bottom layer, thereby achieving a higher mechanical drilling speed; when the drill bit contacts a harder formation, it is only necessary to appropriately increase the drilling pressure to make the first blade 2 contact the hard formation to participate in rock breaking and cutting, so that a single drill bit is suitable for drilling operations in soft to medium-hard formations, avoiding frequent drilling and drilling, with strong adaptability and simple structure. At the same time, during the drilling operation, the water hole 51 introduces the drilling fluid in the liquid flow channel 11 into the chip removal area 4, eliminates the retention and reflux areas, accelerates the discharge of cuttings from the chip removal area 4, prevents the cuttings from clogging the drill bit flow channel and causing mud packing of the drill bit, and avoids repeated cutting and rapid wear of the cutting elements that affect the rock breaking efficiency of the drill bit.

[0033] In some optional embodiments, the angles between any two adjacent first blades 2 are the same. Figure 1As shown, taking the first blade group including three first blades 2 as an example, the three first blades 2 divide 360 ​​degrees equally, and the angle between any two adjacent first blades 2 is 120 degrees, and the same angle makes the force on the three first blades 2 more balanced and stable, thereby improving the stability and reliability of the device.

[0034] In some other optional embodiments, the angle between any two adjacent first blades 2 may also be different and can be set as needed.

[0035] In some optional embodiments, the first blade wing 2 is arranged parallel to the radial direction of the base 1, and the first blade wing 2 is a straight blade wing or a spiral blade wing. The first blade wing 2 is arranged parallel to the radial direction of the base 1, so that the first blade wing 2 and the base 1 are subjected to force together, the torsion resistance of the first blade wing 2 is improved, the reliability and stability of the device are improved, and the service life of the first blade wing 2 can be increased.

[0036] In some optional embodiments, the first blade wing 2 includes a first side surface 21 and a second side surface 22, and the first side surface 21 and the second side surface 22 are arranged opposite to each other along the length direction of the first blade wing 2;

[0037] The first blade 2 is provided with a plurality of first cutting elements 231, the number of which can be flexibly arranged, and the first cutting element 231 can be a small cutting tooth; specifically, the first cutting element 231 includes a first tooth holder 231 and a first polycrystalline diamond composite sheet 232, and the plurality of first tooth holders 231 are linearly arranged on the first side surface 21, and the first polycrystalline diamond composite sheet 232 is connected to the end of the first tooth holder 231 away from the second side surface 22, and this arrangement scheme ensures the tooth density of the core of the drill bit. The first polycrystalline diamond composite sheet 232 can be fixedly connected to the first tooth holder 231 by welding.

[0038] In some optional embodiments, the first tooth holder 231 is integrally formed with the first blade wing 2. The first tooth holder 231 can be made of cemented carbide or other suitable materials and integrally formed with the first blade wing 2, so that the first tooth holder 231 and the first blade wing 2 have better integrity, and the drilling ability of the first polycrystalline diamond composite sheet 232 on the first blade wing 2 can be improved, so that its force bearing capacity is improved, thereby improving the stability of drilling.

[0039] In some optional embodiments, the sum of the number of the first blades 2 and the number of the second blades 3 is at least five, and at least one second blade wing 3 is provided between any two adjacent first blades 2. For example, two first blades 2 are provided, and three second blades 3 are provided, and the angle between the two first blades 2 can be set to 180 degrees, one second blade wing 3 is provided in one angle between the two first blades 2, and two second blades 3 are provided in the other angle between the two first blades 2. This arrangement disperses the stress of the first blade wing 2 and the second blade wing 3, reduces the impact force of the formation on the first blade wing 2 and the second blade wing 3, and the first blade wing 2 and the second blade wing 3 are not easy to break and wear, so that the drill bit of the present invention is suitable for cutting soft to medium-hard formations, and can effectively reduce the bottom hole temperature.

[0040] In some optional embodiments, the second blade wing 3 includes a third side surface 31 and a fourth side surface 32, and the third side surface 31 and the fourth side surface 32 are arranged opposite to each other along the length direction of the second blade wing 3;

[0041] The second blade 3 is provided with a plurality of second cutting elements 33, the number of which can be flexibly arranged, and the second cutting element 33 is a large cutting tooth whose size is larger than that of the first cutting element 231; specifically, the second cutting element 33 includes a second tooth holder 331 and a second polycrystalline diamond composite sheet 332, a plurality of the second tooth holders 331 are linearly arranged on the third side surface 31, the second polycrystalline diamond composite sheet 332 is connected to the end of the second tooth holder 331 away from the fourth side surface 32, and the size of the second polycrystalline diamond composite sheet 332 is larger than that of the first polycrystalline diamond composite sheet 232. The second tooth holder 331 can be made of cemented carbide or other suitable materials and integrated with the second blade 3, so that the second tooth holder 331 and the second blade 3 have better integrity, can improve the drilling ability of the second polycrystalline diamond composite sheet 332 on the second blade 3, and improve its force bearing capacity, thereby improving the stability of drilling; the second polycrystalline diamond composite sheet 332 can be fixedly connected to the second tooth holder 331 by welding.

[0042] In some optional embodiments, the third side surface 31 is further provided with a plurality of the first cutting elements 231 arranged linearly, and the plurality of the first cutting elements 231 are parallel to the plurality of the second cutting elements 33. The large cutting teeth of the second cutting elements 33 are used in conjunction with the small cutting teeth of the first cutting elements 231, and this arrangement scheme increases the tooth density of the shoulder while ensuring the tooth density of the core of the drill bit, thereby overcoming the weak link caused by the limitation of the second blade 3.

[0043] In some optional embodiments, the second blade wing 3 is arranged radially along the top of the base 1; the second blade wing 3 is a straight blade wing or a spiral blade wing. The use of this design can effectively improve the scope of application of the present invention and improve the applicability of the present invention.

[0044] In some optional embodiments, the hydraulic structure 5 further includes a nozzle, which is connected to the water hole 51 and faces the chip removal area 4. The nozzle is used to increase the pressure of the drilling fluid in the water hole 51, so that the drilling fluid has a better injection effect and the cuttings can be better flushed out of the chip removal area 4.

[0045] In some optional embodiments, a hydraulic structure 5 can be set in front of the first blade 2 and the second blade 3 to increase the flow field of the drill bit, effectively prevent mud packing, eliminate retention and reflux areas, accelerate the discharge of cuttings from the chip discharge area 4, avoid repeated cutting by the first cutting element 231 and the second cutting element 33, and well protect the first cutting element 231 and the second cutting element 33, thereby improving the rock drilling efficiency and service life of the drill bit.

[0046] In some optional embodiments, a connecting structure 12 is provided at one end of the base 1 away from the first blade group, and the connecting structure 12 is used to connect the drill rod. The connecting structure 12 is integrally formed with the base 1, and the connecting structure 12 may include a connecting thread 121, and the connecting thread 121 is used to connect the drill rod; a diameter protection structure 13 is provided on the outer wall of the base 1 near the second blade group, and the diameter protection structure 13 can be arranged on the circumferential side of the base 1 near the top where the second blade 3 emerges, and the diameter protection structure 13 can be a wear-resistant material layer surrounding and attached to the circumferential side of the base 1. The setting of the diameter protection structure 13 can help improve the stability of the drill bit.

[0047] The working principle of the fractured blade type PDC drill bit provided in the embodiment of the present application is as follows: when the fractured blade type PDC drill bit is used for drilling, the mud pump drives the drilling fluid into the liquid flow channel 11 of the base body 1 through the drill pipe connected to the bottom connection structure 12 of the base body 1. When the drill bit contacts a softer formation, the large second cutting elements 33 on each second blade 3 of the second blade group act first, and a single large second cutting element 33 penetrates deeper into the bottom layer, thereby achieving a higher mechanical drilling speed; when the drill bit contacts a harder formation, it is only necessary to increase the drilling pressure appropriately so that the first blade 2 arranged in a staggered manner with the second blade 3 contacts the hard formation to participate in rock breaking and cutting. This design increases the overall tooth density of the drill bit and improves the service life of the drill bit; in this process, the hydraulic structure 5 correspondingly arranged in front of the first blade 2 and the second blade 3 eliminates the retention and reflux areas, accelerates the discharge of cuttings from the chip removal area 4, and avoids repeated cutting of the cutting elements; the entire drilling process does not require the drill to be pulled up and the drill bit to be replaced, but can be completed using a single drill bit.

[0048] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0049] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral 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 this application can be understood according to specific circumstances.

[0051] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0052] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A fracture blade type PDC drill bit, characterized in that: It includes a base, a first blade group, a second blade group and a hydraulic structure, wherein: The substrate includes a liquid flow channel, and the liquid flow channel is used to provide a flow channel for drilling fluid; The first blade group includes at least two first blades, the first blades extend outward from the center of the end of the base, and the area enclosed by two adjacent first blades and the base forms a chip removal area; The second blade group includes at least two second blades, the second blades extend outward from the outer edge of the end of the base, and the height of the second blade is greater than the height of the first blade, and at least two of the second blades and at least two of the first blades are arranged in a staggered manner relative to each other along the circumference of the base; The hydraulic structure is arranged in at least one of the chip removal areas, and the hydraulic structure at least comprises a water eye, and the water eye is connected to the liquid flow channel.

2. The fractured blade type PDC drill bit according to claim 1, characterized in that: The included angles between any two adjacent first blades are the same.

3. The fractured blade type PDC drill bit according to claim 2, characterized in that: The first blade wing is arranged parallel to the radial direction of the base, and the first blade wing is a straight blade wing or a spiral blade wing.

4. The fractured blade type PDC drill bit according to claim 3, characterized in that: The first blade wing comprises a first side surface and a second side surface, and the first side surface and the second side surface are arranged opposite to each other along the length direction of the first blade wing; A plurality of first cutting elements are arranged on the first blade, and the first cutting elements include a first tooth support and a first polycrystalline diamond composite sheet. The plurality of first tooth supports are linearly arranged on the first side surface, and the first polycrystalline diamond composite sheet is connected to an end of the first tooth support away from the second side surface.

5. The fractured blade type PDC drill bit according to claim 4, characterized in that: The first tooth support and the first blade wing are integrally formed.

6. The fractured blade type PDC drill bit according to claim 4, characterized in that: The sum of the number of the first blade wings and the number of the second blade wings is at least five, and at least one second blade wing is arranged between any two adjacent first blade wings.

7. The fractured blade type PDC drill bit according to claim 6, characterized in that: The second blade wing comprises a third side surface and a fourth side surface, and the third side surface and the fourth side surface are arranged opposite to each other along the length direction of the second blade wing; A plurality of second cutting elements are arranged on the second blade, and the second cutting elements include a second tooth support and a second polycrystalline diamond composite sheet. The plurality of second tooth supports are linearly arranged on the third side surface, and the second polycrystalline diamond composite sheet is connected to an end of the second tooth support away from the fourth side surface, and the size of the second polycrystalline diamond composite sheet is larger than that of the first polycrystalline diamond composite sheet.

8. The fractured blade type PDC drill bit according to claim 7, characterized in that: A plurality of the first cutting elements arranged linearly are also disposed on the third side surface, and the plurality of the first cutting elements are parallel to the plurality of the second cutting elements.

9. The fractured blade type PDC drill bit according to any one of claims 1 to 8, characterized in that: The hydraulic structure further comprises a nozzle, which is connected to the water hole and faces the chip discharge area.

10. The fractured blade type PDC drill bit according to claim 9, characterized in that: A connecting structure is arranged at one end of the base body away from the first blade wing group, and the connecting structure is used to connect a drill rod; a diameter protection structure is arranged at a position of the outer wall of the base body close to the second blade wing group.

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