Impact composite drill bit

Abstract

The present invention relates to the technical field of drilling equipment, and is an impact composite drill bit, comprising a drill bit body, a rotating shaft, a center wheel and a main blade. A mounting groove with an opening upward is provided at the center of the upper end of the drill bit body, a horizontally arranged rotating shaft is rotatably installed in the mounting groove, and a center wheel is fixedly installed on the outer side of the middle of the rotating shaft. The present invention has a reasonable and compact structure. When in use, the lower end of the impact composite drill bit is connected to a pipe string and then lowered into a target position in the well. When the drill bit body contacts the rock formation, the center wheel starts to rotate. The cross section of the center wheel is an arc triangle. When the center wheel rotates, the high point and the low point of the triangle of the cross section of the center wheel are constantly switching. The main cutting teeth on the main blade will also form an impact effect on the rock formation with the switching of the high point and the low point, which has the effect of breaking the rock formation, thereby improving the working efficiency of the impact composite drill bit. When drilling in a mudstone formation, the friction in the center of the impact composite drill bit can be reduced, thereby improving the drilling efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of drilling equipment and relates to an impact composite drill bit. Background Art

[0002] Polycrystalline Diamond Compact (PDC) drill bits, referred to as PDC drill bits, are one of the most commonly used rock-breaking tools in oil and gas drilling projects. PDC drill bits are mostly designed as blade-wing structures. PDC teeth are arranged on the crown of the blades of the drill body, and hydraulic chip grooves of the drill bit are formed between the blades. PDC teeth are composed of a polycrystalline diamond layer and a cemented carbide base. The polycrystalline diamond layer has the high hardness and high wear resistance of diamond, but also has a certain degree of brittleness. PDC teeth are generally cylindrical. When the PDC drill bit is working to break rock, the PDC teeth are pressed into (invaded) the formation by drilling pressure, and the rock is scraped and broken under the rotation of the drill body. Generally speaking, the smaller the size of the PDC teeth (referring to the diameter of the cylinder), the easier it is to invade the formation. However, the smaller the size of the PDC teeth, the smaller the scraping and breaking of rock during scraping, and the smaller the coverage area of ​​the teeth. When drilling in softer formations, larger PDC teeth are generally used to increase the amount of rock scraping and breaking by the PDC teeth, thereby improving the drilling efficiency of soft formations; when drilling in hard formations, smaller PDC teeth are generally used to enhance the ability and depth of the PDC teeth to invade the formation, thereby increasing the drilling speed.

[0003] At present, ordinary fixed blade PDC drill bits have fixed blades in the center. When they contact the rock formation in the well, they plow the formation. Especially when drilling in mudstone formations, the friction in the center of the drill bit is relatively large, resulting in low drilling efficiency. Summary of the invention

[0004] The present invention provides an impact composite drill bit, which overcomes the above-mentioned deficiencies of the prior art and can effectively solve the problems of large friction and low drilling efficiency of the existing PDC drill bit during contact with rock formations in the well.

[0005] The technical solution of the present invention is achieved through the following measures: an impact composite drill bit, comprising a drill bit body, a rotating shaft, a center wheel and a main blade, a mounting groove with an opening upward is provided in the center of the upper end of the drill bit body, a horizontally arranged rotating shaft is rotatably installed in the mounting groove, a center wheel is fixedly installed on the outer side of the middle part of the rotating shaft, a plurality of grinding teeth for crushing rock formations are distributed at intervals along the circumference on the outer side of the center wheel, a plurality of main blades are evenly distributed at intervals along the circumference on the outer side of the upper part of the drill bit body, the main blades are divided into a first inner cone section, a first nose section, a first shoulder section, a first outer cone section and a first gauge section from the inside to the outside along the crown contour, a plurality of main cutting teeth are arranged at intervals from the inside to the outside on the first inner cone section, the first nose section, the first shoulder section and the first outer cone section of each main blade, a plurality of main cutting teeth are arranged at intervals from the inside to the outside, a drill bit inner cavity with an upper part located below the mounting groove is provided at the lower end of the drill bit body, a plurality of flushing holes are distributed at intervals along the circumference on the upper part of the drill bit body, a first end of each flushing hole is connected to the drill bit inner cavity, and a second end of each flushing hole extends to the outer side of the upper part of the drill bit body.

[0006] The following are further optimizations and / or improvements to the above technical solutions:

[0007] The above-mentioned center wheel may include a first rotating wheel and a second rotating wheel symmetrically fixedly installed on the outside of the rotating shaft. The cross-section of the first rotating wheel is an arc triangle. The outsides of the first rotating wheel and the second rotating wheel are both provided with a plurality of grinding teeth spaced circumferentially, and each grinding tooth is provided with a chamfered structure on both sides of the central axis of the rotating shaft.

[0008] The cross-sectional area of ​​the first rotating wheel may gradually decrease in a direction away from the second rotating wheel, the cross-sectional area of ​​the grinding teeth is a trapezoid with a narrow outer side and a wide inner side, and the outer side of the grinding teeth is provided with an arc chamfer.

[0009] The first inner cone section of each main blade wing can extend inwardly into the mounting groove, and the lower end of the first inner cone section corresponding to the mounting groove position is provided with an arc-shaped groove opening downward.

[0010] Auxiliary blade wings can be fixed on the outside of the drill body between the two adjacent main blade wings. The auxiliary blade wings are divided into a second inner cone section, a second nose section, a second shoulder, a second outer cone section and a second gauge guard section from the inside to the outside along the crown contour. A number of auxiliary cutting teeth are arranged on the second inner cone section, the second nose section, the second shoulder, the second outer cone section and the second gauge guard section of each auxiliary blade wing from the inside to the outside. A chip groove is formed between each auxiliary blade wing and the main blade wing at the adjacent position, and the second end of each flushing hole extends to the outside of the upper part of the drill body corresponding to the chip groove.

[0011] At least one perforation may be provided on the outer side of the upper end of the drill body corresponding to the position between the second inner cone section and the mounting groove. The lower part of each perforation is connected to the inner cavity of the drill bit. A nozzle is fixedly installed on the inner side of the upper part of the perforation. The upper part of the nozzle has an outlet opposite to the mounting groove.

[0012] The present invention has a reasonable and compact structure. When in use, the lower end of the impact composite drill bit is connected to the pipe string and then lowered into the target position in the well. When the drill bit body contacts the rock formation, the center wheel starts to rotate. The cross section of the center wheel is an arc triangle. When the center wheel rotates, the high point and the low point of the triangle in the cross section of the center wheel are constantly switching. The main cutting teeth on the main blades will also form an impact effect on the rock formation as the high point and the low point are switched, so as to break the rock formation and improve the working efficiency of the impact composite drill bit. When drilling in mudstone formations, the friction in the center of the impact composite drill bit can be reduced, thereby improving the drilling efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attached Figure 1 It is a schematic diagram of the front cross-sectional structure of embodiments one to six of the present invention.

[0014] Attached Figure 2 It is a schematic diagram of the top view of the structure of Embodiments 1 to 6 of the present invention after the center wheel is removed.

[0015] Attached Figure 3 It is a schematic diagram of the front structural view of the center wheel of embodiments 1 to 6 of the present invention.

[0016] Attached Figure 4 It is a schematic diagram of the left side structure of the center wheel of embodiments 1 to 6 of the present invention.

[0017] Attached Figure 5 Schematic diagram of radial covering tooth arrangement of the main cutting teeth in embodiments 1 to 6 of the present invention.

[0018] Attached Figure 6 Schematic diagram of radial covering tooth arrangement of auxiliary cutting teeth in embodiment 5 of the present invention.

[0019] The codes in the accompanying drawings are: 1 is the drill body, 2 is the mounting groove, 3 is the rotating shaft, 4 is the grinding tooth, 5 is the main blade wing, 6 is the main cutting tooth, 7 is the inner cavity of the drill, 8 is the flushing hole, 9 is the first rotating wheel, 10 is the second rotating wheel, 11 is the arc chamfer, 12 is the arc groove, 13 is the nozzle, 14 is the outlet, 15 is the secondary blade wing, 16 is the chip groove, 17 is the secondary cutting tooth, and 18 is the auxiliary cutting tooth. DETAILED DESCRIPTION

[0020] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0021] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1 The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 It is determined by the layout direction.

[0022] The present invention will be further described below in conjunction with embodiments and drawings:

[0023] Embodiment 1: As shown in the attached Figures 1 to 5 As shown, the impact composite drill bit includes a drill body 1, a rotating shaft 3, a center wheel and a main blade 5. A mounting groove 2 with an opening upward is provided at the center of the upper end of the drill body 1. A horizontally arranged rotating shaft 3 is rotatably installed in the mounting groove 2. A center wheel is fixedly installed on the outer side of the middle of the rotating shaft 3. A plurality of grinding teeth 4 for crushing rock formations are distributed at intervals along the circumference on the outer side of the upper part of the drill body 1. A plurality of main blades 5 are evenly distributed at intervals along the circumference on the outer side. The main blades 5 are divided into a first inner cone from the inside to the outside along the crown contour. The drill bit body 1 has a first inner cone section, a first nose section, a first shoulder section, a first outer cone section and a first gauge section. The first inner cone section, the first nose section, the first shoulder section and the first outer cone section of each main blade 5 are provided with a plurality of main cutting teeth 6 spaced from the inside to the outside. The lower end of the drill body 1 is provided with a drill cavity 7 whose upper part is located below the mounting groove 2. The upper part of the drill body 1 is provided with a plurality of flushing holes 8 spaced along the circumferential direction. The first end of each flushing hole 8 is connected to the drill cavity 7, and the second end of each flushing hole 8 extends to the outer side of the upper part of the drill body 1.

[0024] According to the requirements, the main cutting teeth 6 are the existing well-known PDC teeth. When in use, the lower end of the impact composite drill bit is connected to the pipe string and then lowered into the target position in the well. When the drill bit body 1 contacts the rock formation, the center wheel starts to rotate. The cross section of the center wheel is an arc triangle. When the center wheel rotates, the high point and the low point of the cross section triangle of the center wheel are constantly switching. The main cutting teeth 6 on the main blade 5 will also form an impact effect on the rock formation as the high point and the low point switch, which has the effect of breaking the rock formation, improving the working efficiency of the impact composite drill bit. When drilling in mudstone formations, the friction in the center of the impact composite drill bit can be reduced, thereby improving the drilling efficiency.

[0025] The above impact composite drill bit can be further optimized and / or improved according to actual needs:

[0026] Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figure 1 , 3 As shown in , 4, the center wheel includes a first rotating wheel 9 and a second rotating wheel 10 which are symmetrically fixedly installed on the outside of the rotating shaft 3. The cross-section of the first rotating wheel 9 is an arc triangle. A plurality of grinding teeth 4 are distributed along the circumferential direction on the outside of the first rotating wheel 9 and the outside of the second rotating wheel 10. Each grinding tooth 4 is provided with a chamfered structure on both sides of the central axis of the rotating shaft 3.

[0027] During use, when the drill body 1 contacts the rock formation, the first rotating wheel 9 and the second rotating wheel 10 start to rotate. The cross-section of the first rotating wheel 9 and the second rotating wheel 10 is an arc triangle. When the first rotating wheel 9 and the second rotating wheel 10 rotate, the high point and the low point of the cross-section triangle of the first rotating wheel 9 and the second rotating wheel 10 are constantly switching, and the main cutting teeth 6 on the main blade wing 5 will also have an impact effect on the rock formation as the high point and the low point are switched, thereby breaking the rock formation and improving the working efficiency of the impact composite drill bit. Each grinding tooth 4 is provided with a chamfered structure on both sides of the central axis of the rotating shaft 3, which can reduce the torque of the grinding tooth 4, avoid the breakage of the grinding tooth 4, and extend the service life of the grinding tooth 4.

[0028] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figure 1 , 3 As shown in FIG. 4 , the cross-sectional area of ​​the first rotating wheel 9 gradually decreases in the direction away from the second rotating wheel 10 , the cross-sectional area of ​​the grinding tooth 4 is a trapezoid with a narrow outside and a wide inside, and an arc chamfer 11 is provided on the outer side of the grinding tooth 4 .

[0029] During use, the cross-sectional area of ​​the first rotating wheel 9 gradually decreases in the direction away from the second rotating wheel 10, and the first rotating wheel 9 and the second rotating wheel 10 are symmetrically arranged, that is, the cross-sectional area of ​​the second rotating wheel 10 gradually decreases in the direction away from the first rotating wheel 9, so as to ensure the spacing between the grinding teeth 4 and the main blade wing 5, and prevent mud from accumulating in the gap between the grinding teeth 4 and the main blade wing 5 to affect the rotation of the first rotating wheel 9 and the second rotating wheel 10. The cross-section of the grinding tooth 4 is a trapezoid with a narrow outside and a wide inside, so as to improve the strength of the grinding tooth 4. The outer side of the grinding tooth 4 is provided with an arc chamfer 11, that is, an arc transition between the two inclined surfaces of the cross-section of the grinding tooth 4 (the two waists of the trapezoid), so as to reduce the wear of the grinding tooth 4 by mud and extend the service life of the grinding tooth 4.

[0030] Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown, the first inner cone section of each main blade wing 5 extends inwardly into the mounting groove 2, and the lower end of the first inner cone section corresponding to the position of the mounting groove 2 is provided with an arc-shaped groove 12 opening downward.

[0031] During use, an arc-shaped groove 12 with an opening downward is provided at the lower end of the first inner cone section, so that the first rotating wheel 9 and the second rotating wheel 10 can avoid the grinding teeth 4 on the outside of the first rotating wheel 9 and the outside of the second rotating wheel 10 from scratching the lower end of the first inner cone section of the main blade 5 during rotation, thereby ensuring the rotation space of the first rotating wheel 9, the second rotating wheel 10 and the grinding teeth 4. The first inner cone section of each main blade wing 5 extends inward into the mounting groove 2, so that when the first rotating wheel 9 and the second rotating wheel 10 rotate, the grinding teeth 4 interact with the end of the first inner cone section of the main blade wing 5, thereby avoiding the formation of mud bags on the outside of the first rotating wheel 9 and the second rotating wheel 10, thereby improving drilling efficiency.

[0032] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2 As shown in Figures 6 and 7, an auxiliary blade wing 15 is fixed to the outer side of the drill body 1 between two adjacent main blade wings 5. The auxiliary blade wings 15 are divided into a second inner cone section, a second nose section, a second shoulder, a second outer cone section and a second gauge section along the crown contour from the inside to the outside. A plurality of auxiliary cutting teeth 17 are arranged on the second inner cone section, the second nose section, the second shoulder, the second outer cone section and the second gauge section of each auxiliary blade wing 15 at intervals from the inside to the outside. A chip groove 16 is formed between each auxiliary blade wing 15 and the main blade wing 5 at the adjacent position, and the second end of each flushing hole 8 extends to the outer side of the upper part of the drill body 1 corresponding to the chip groove 16.

[0033] A chip groove 16 is formed between each secondary blade wing 15 and the primary blade wing 5 at the adjacent position and the outer side of the drill body 1 at the corresponding position. The arrangement of the secondary cutting teeth 17 and the primary cutting teeth 6 can make the transition of the cutting profile of the drill bit smoother and avoid abnormal loading and failure of the cutting teeth. The main cutting teeth 6 and the secondary cutting teeth 17 are used on the drill bit to enhance the adaptability of the drill bit to the formation. When drilling in soft formations, the main cutting teeth 6 can increase the scraping and rock breaking amount of the drill bit and ensure the drilling speed of the drill bit in soft formations.

[0034] According to the requirements, the auxiliary cutting teeth 17 are the existing well-known PDC teeth. Along the rotation direction of the drill bit body 1 during drilling, the front sides of the main blade wing 5 and the auxiliary blade wing 15 are cutting sides, the ends of the main cutting teeth 6 are located in front of the cutting sides of the main blade wing 5, and the ends of the auxiliary cutting teeth 17 are located in front of the cutting sides of the auxiliary blade wing 15. A number of auxiliary cutting teeth 18 are arranged at intervals on the outside of the main blade wing 5 and the outside of the auxiliary blade wing 15. There is a distance between the auxiliary cutting teeth 18 and the cutting sides of the blade wings. The auxiliary cutting teeth 18 can limit the penetration depth of the main cutting teeth 6 and the auxiliary cutting teeth 17, help the main cutting teeth 6 and the auxiliary cutting teeth 17 to bear part of the impact load, reduce the probability of vibration and cracking of the drill bit, protect the sharpness of the main cutting teeth 6 and the auxiliary cutting teeth 17 of the drill bit, and improve the mechanical drilling speed during drilling of the drill bit.

[0035] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figure 2 As shown, at least one perforation is provided on the outer side of the upper end of the drill body 1 corresponding to the position between the second inner cone section and the mounting groove 2, the lower part of each perforation is connected to the drill cavity 7, and a nozzle 13 is fixedly installed on the inner side of the upper part of the perforation, and the upper part of the nozzle 13 has an outlet 14 opposite to the mounting groove 2.

[0036] According to the needs, a perforation is provided on the outer side of the upper end of the drill bit body 1 corresponding to the position between the second inner cone section and the mounting groove 2. The upper part of the nozzle 13 has an outlet 14 opposite to the mounting groove 2. The drilling fluid flowing out of the outlet 14 can impact the grinding teeth 4, so that the first rotating wheel 9 and the second rotating wheel 10 rotate, so that the mud debris on the surface of the first rotating wheel 9 and the second rotating wheel 10 can be washed away, thereby improving the drilling efficiency of the mudstone formation.

[0037] The above technical features respectively constitute various embodiments of the present invention, which have strong adaptability and optimal implementation effects. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. An impact composite drill bit, characterized in that The invention comprises a drill bit body, a rotating shaft, a center wheel and a main blade. A mounting groove with an opening upward is provided in the center of the upper end of the drill bit body. A horizontally arranged rotating shaft is rotatably installed in the mounting groove. A center wheel is fixedly installed on the outer side of the middle of the rotating shaft. A plurality of grinding teeth for crushing rock formations are distributed at intervals along the circumference on the outer side of the center wheel. A plurality of main blades are evenly distributed at intervals along the circumference on the outer side of the upper part of the drill bit body. The main blades are divided into a first inner cone section, a first nose section, a first shoulder section, a first outer cone section and a first gauge section from the inside to the outside along the crown contour. A plurality of main cutting teeth are arranged at intervals from the inside to the outside on the first inner cone section, the first nose section, the first shoulder section and the first outer cone section of each main blade. A drill bit inner cavity with an upper part located below the mounting groove is provided at the lower end of the drill bit body. A plurality of flushing holes are distributed at intervals along the circumference on the upper part of the drill bit body. The first end of each flushing hole is connected to the drill bit inner cavity, and the second end of each flushing hole extends to the outer side of the upper part of the drill bit body. The center wheel includes a first rotating wheel and a second rotating wheel symmetrically fixedly mounted on the outer side of the rotating shaft, the cross section of the first rotating wheel is an arc triangle, and a plurality of grinding teeth are distributed at intervals along the circumferential direction on the outer side of the first rotating wheel and the outer side of the second rotating wheel, and each grinding tooth is provided with a chamfer structure on both sides along the central axis of the rotating shaft; The cross-sectional area of ​​the first rotating wheel gradually decreases in the direction away from the second rotating wheel, the cross-sectional area of ​​the grinding teeth is a trapezoidal shape with a narrow outside and a wide inside, and the outer side of the grinding teeth is provided with a circular arc chamfer; When the drill bit body contacts the rock formation, the center wheel starts to rotate. The cross-section of the center wheel is an arc triangle. When the center wheel rotates, the high and low points of the triangle in the cross-section of the center wheel are constantly switching, and the main cutting teeth on the main blade will have an impact effect on the rock formation as the high and low points switch.

2. The impact composite drill bit according to claim 1, characterized in that The first inner cone section of each main blade wing extends inwardly into the mounting groove, and an arc-shaped groove opening downward is provided at the lower end of the first inner cone section corresponding to the mounting groove position.

3. The impact composite drill bit according to claim 1 or 2, characterized in that Auxiliary blade wings are fixed on the outside of the drill body between two adjacent main blade wings. The auxiliary blade wings are divided into a second inner cone section, a second nose section, a second shoulder, a second outer cone section and a second gauge section from the inside to the outside along the crown contour. A number of auxiliary cutting teeth are arranged on the second inner cone section, the second nose section, the second shoulder, the second outer cone section and the second gauge section of each auxiliary blade wing from the inside to the outside. A chip groove is formed between each auxiliary blade wing and the main blade wing at the adjacent position, and the second end of each flushing hole extends to the outside of the upper part of the drill body corresponding to the chip groove.

4. The impact composite drill bit according to claim 3, characterized in that At least one perforation is provided on the outer side of the upper end of the drill body corresponding to the position between the second inner cone section and the mounting groove, the lower part of each perforation is connected to the inner cavity of the drill bit, a nozzle is fixedly installed on the inner side of the upper part of the perforation, and the upper part of the nozzle has an outlet opposite to the mounting groove.

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