Sliding drill bit

Abstract

The invention relates to the technical field of drill bits, in particular to a sliding drill bit which comprises a drill bit body and rolling bodies, and a plurality of main blades are evenly distributed on the outer side of the upper portion of the drill bit body along the circumference at intervals. The structure is ingenious in conception, the rolling bodies are located on the rear row of the main cutting teeth on the main blades, located at the highest position of the outer contour of the main blades and lower than the front row of the main cutting teeth, and the rolling bodies can play a role in limiting excessive penetration of the main cutting teeth into the stratum, so that the main cutting teeth have consistent penetration depth, stable cutting depth is provided, and the service life of the main cutting teeth is prolonged. Therefore, vibration of the drill bit body can be reduced, torque fluctuation can be reduced, friction force between the main blades and the stratum can be reduced when the rolling bodies roll on the stratum, the rolling grinding effect of the drill bit body is increased on the basis of a single sliding ploughing drilling mode, the mechanical rotating speed of the drill bit body can be increased conveniently, and therefore the drilling speed and the drilling pressure are increased. And the control capability of the tool surface is improved.

Description

Technical Field

[0001] The invention relates to the technical field of drill bits and particularly relates to a sliding drill bit. Background Art

[0002] A drill bit is a rock-breaking tool used to break rock and form a wellbore in drilling projects. The drill bit body has both fixed cutting structures and non-fixed cutting structures (such as a cone structure). Composite drill bits are a new type of rock-breaking tool that has gradually emerged and been widely used in recent years. Composite drill bits use the combined action of different cutting structures to break rock, and can significantly increase drilling speed in some difficult-to-drill formations.

[0003] Chinese patent document publication number CN106368615A discloses a composite drill bit with a steering wheel disc, which includes a drill bit body, a wheel disc, a gear ring provided on the wheel disc, and the wheel disc can rotate relative to the drill bit body. The drill bit body is provided with at least one steering wheel disc, which consists of a wheel disc and a steering seat. The steering seat is mounted on the drill bit body through a rotating connection, and the steering seat can rotate relative to the drill bit body. The wheel disc is mounted on the steering seat through a rotating connection, and the wheel disc can rotate relative to the steering seat. The rotation axis of the wheel disc is offset relative to the rotation axis of the steering seat, and the offset distance is greater than one twentieth of the radius of the wheel disc gear ring and less than three times the diameter of the wheel disc gear ring. The rotation axis of the steering seat of the steering wheel disc near the drill bit center does not coincide with the drill bit axis. The drill bit body is also provided with a fixed cutting structure or a non-fixed cutting structure. The steering seat installed on the drill bit body can rotate in any direction, mainly to solve the problem of short life of the wheel cutting teeth and improve the rock breaking efficiency. However, the structure is complicated and easily damaged when the underground drilling pressure is too high. When the drill bit body is drilling underground, the drill bit jumps and vibrates too much, which can easily damage the structure. The wheel is subjected to various force directions, and the direction of the wheel cannot be kept consistent with the rotation direction of the drill bit body.

[0004] Chinese patent publication CN117287123A discloses a PDC drill bit with a disc cutter and rotatable cutting teeth. The drill bit comprises a drill body and blades, with the blades disposed on the drill body. At least one blade is equipped with both a rotating tooth and a disc cutter. The rotating tooth comprises a central rotating tooth, a bushing, a rotating tooth rotation shaft, and a stopper. The rotating tooth rotation shaft is provided with a first gear, the central rotating tooth being rotationally connected to the bushing, and the rotating tooth being fixed to the blade via the bushing. The disc cutter comprises a cutter disc and a cutter disc shaft, with a second gear disposed on the cutter disc shaft. The disc cutter is connected to the blades, and the rotating teeth and the disc cutter are meshed with gears. This drill bit primarily drives the front row of central rotating teeth by rotating the rotating teeth on the side of the blades, thereby increasing the service life of the diamond layer on the front row of central rotating teeth. However, because the front row of central rotating teeth are constantly rotating, the drill bit is prone to deviation and has poor stability.

[0005] Chinese patent publication CN117027659A discloses a design method for a blade-type PDC composite drill bit. The method first determines the formation shear strength and internal friction angle using field logging data, then determines the drill bit diameter based on drilling conditions. The number of cones is then determined based on the drill bit diameter, evenly distributing the cones across the blades. The radial position and coverage area of ​​the cones are then determined based on the drill bit diameter and the formation internal friction angle. Finally, the axial inclination angle of the cones is determined based on the shear strength of the formation. This design method combines field test data, classified discussions, and numerical calculations to design the composite drill bit's cone structural parameters. However, the composite drill bit designed using this method incorporates cone bits on fixed blades, which does not limit the bit's cutting teeth from cutting into the drill bit. Summary of the Invention

[0006] The present invention provides a sliding drill bit, which overcomes the above-mentioned shortcomings of the prior art and can effectively solve the problem that the existing drill bit is easily vibrated and has large torque fluctuations during drilling, resulting in the inability to increase the drilling speed and drilling pressure.

[0007] The technical solution of the present invention is achieved through the following measures: a sliding drill bit, including a drill bit body and a rolling body, a plurality of main cutting wings are evenly distributed along the circumference of the outer side of the upper part of the drill bit body, and the main cutting wings are divided into a first inner cone section, a first nose, a first shoulder, a first outer cone section and a first gauge portion from the inside to the outside along the crown contour, and a plurality of main cutting teeth are arranged on the first inner cone section, the first nose, the first shoulder and the first outer cone section of each main cutting wing from the inside to the outside, and each first nose is provided with a mounting groove with an upward opening in the counterclockwise direction, and a rolling body is rotatably installed in the mounting groove, and the rotation axis of the rolling body is arranged along the radial direction of the drill bit body, and the highest point of the rolling body is not higher than the highest point of the main cutting tooth on the first nose.

[0008] The following are further optimizations and / or improvements to the above technical solutions: The rolling body may be cylindrical, with a fixed shell fixedly mounted on the inner side of the mounting groove, and the outer side of the rolling body being sleeved on the inner side of the fixed shell.

[0009] The rolling body may include three first support bodies spaced apart along the length direction and a second support body fixed between two adjacent first support bodies.

[0010] The material of the first support body may be diamond, and the material of the second support body may be cemented carbide.

[0011] An auxiliary blade wing can be fixed on the outside of the drill body between the two adjacent main blades. The auxiliary blade wing is divided into a second inner cone section, a second nose, a second shoulder, a second outer cone section and a second gauge section along the crown contour from the inside to the outside. A number of auxiliary cutting teeth are arranged on the second inner cone section, the second nose, 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. A flushing cavity is provided at the lower end of the drill body. At least one flushing hole is distributed at intervals in each chip groove, and the other end of each flushing hole is connected to the flushing cavity.

[0012] The present invention has an ingenious structural conception. The rolling body is located in the rear row of the main cutting teeth on the main blade, at the highest position of the outer contour of the main blade, lower than the front row of the main cutting teeth. The setting of the rolling body can limit the main cutting teeth from excessively penetrating into the formation, so that the main cutting teeth have a consistent penetration depth and provide a stable cutting depth. This can reduce the vibration of the drill bit body and reduce torque fluctuations. When the rolling body rolls on the formation, it can reduce the friction between the main blade and the formation. In this way, the drill bit body increases the rolling grinding effect on the basis of the single sliding plowing drilling method, which facilitates the increase of the mechanical speed of the drill bit body, thereby increasing the drilling speed and drilling pressure, and improving the control ability of the tool face. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attachment Figure 1 It is a schematic diagram of the main cross-sectional structure of embodiments one to four of the present invention.

[0014] Attachment Figure 2 Schematic diagrams of top views of the structures of embodiments one to four of the present invention.

[0015] Attachment Figure 3 Schematic diagram of the top structure of the fixed shell in embodiments 2 to 4 of the present invention.

[0016] Attachment Figure 4 Schematic diagrams of top-view cross-sectional structures of rolling bodies in embodiments 2 to 4 of the present invention.

[0017] Attachment Figure 5 Schematic diagram of the side cross-sectional structure of the fixing housing in embodiments 2 to 4 of the present invention.

[0018] Attachment Figure 6 Schematic diagram of radial covering tooth arrangement of the main cutting teeth in Examples 1 to 4 of the present invention.

[0019] Attachment Figure 7 Schematic diagram of radial covering arrangement of auxiliary cutting teeth in embodiment 4 of the present invention.

[0020] Attachment Figure 8 This is a graph showing the average drilling time of the fourth embodiment of the present invention and a conventional drill bit.

[0021] Attachment Figure 9 The following is a comparison chart of the drilling speed and bit pressure of the fourth embodiment of the present invention and the existing drill bit when drilling at different depths.

[0022] The codes in the accompanying drawings are: 1 is the drill body, 2 is the main blade, 3 is the main cutting tooth, 4 is the fixed shell, 5 is the first support body, 6 is the second support body, 7 is the auxiliary blade, 8 is the auxiliary cutting tooth, 9 is the chip groove, 10 is the flushing chamber, 11 is the flushing hole, and 12 is the guard plate. DETAILED DESCRIPTION

[0023] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0024] In the present invention, for the convenience of description, the relative position relationship of each component is described based on the Figure 1 The positional relationships of front, back, top, bottom, left, and right are described in the layout of the manual. Figure 1 The layout direction is determined by the

[0025] The present invention will be further described below in conjunction with the embodiments and accompanying drawings: Example 1: As shown in the attached Figure 1 、 2 As shown in Figures 6 and 7, the sliding drill bit includes a drill body 1 and a rolling body. A number of main blades 2 are evenly spaced along the circumference of the outer side of the upper part of the drill body 1. The main blades 2 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 along the crown contour from the inside to the outside. A number of main cutting teeth 3 are arranged on the first inner cone section, the first nose section, the first shoulder section and the first outer cone section of each main blade 2 from the inside to the outside. In the counterclockwise direction, each first nose section is provided with a mounting groove opening upward, and a rolling body is rotatably mounted in the mounting groove. The rotation axis of the rolling body is arranged along the radial direction of the drill body 1, and the highest point of the rolling body is not higher than the highest point of the main cutting tooth 3 on the first nose section.

[0026] The rolling body is located in the rear row of the main cutting teeth 3 on the main blade 2, at the highest position of the outer contour of the main blade 2, lower than the front row of the main cutting teeth 3. The setting of the rolling body can limit the main cutting teeth 3 from excessively penetrating into the formation, so that the main cutting teeth 3 have a consistent penetration depth and provide a stable cutting depth, which can reduce the vibration of the drill bit body 1 and reduce torque fluctuations. When the rolling body rolls on the formation, it can reduce the friction between the main blade 2 and the formation. In this way, the drill bit body 1 adds a rolling grinding effect on the basis of a single sliding plowing drilling method, which facilitates increasing the mechanical speed of the drill bit body 1, thereby increasing the drilling speed and drilling pressure, and improving the control ability of the tool face.

[0027] The above sliding drill bit can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above example, as shown in the attached Figure 1 、 2 As shown in Figure 3, the rolling body is cylindrical, a fixed shell 4 is fixedly installed on the inner side of the mounting groove, and the outer side of the rolling body is sleeved on the inner side of the fixed shell 4.

[0028] According to requirements, the fixed shell 4 can be a box-shaped structure with an opening at the top, the width of the opening is smaller than the diameter of the rolling element, and the depth of the fixed shell 4 is larger than the radius of the rolling element and smaller than the diameter of the rolling element, that is, the cross-section of the cavity inside the fixed shell 4 is in the shape of an arc. In order to facilitate the installation of the rolling element, the width of the opening can also be set to be larger than the diameter of the rolling element. Then, an arc-shaped guard plate 12 is fixedly installed on the inner side of the rear of the fixed shell 4 in a counterclockwise direction. The guard plate 12 is mounted on the outer side of the rear of the rolling element. In this way, the thickness of the guard plate 12 can reduce the width of the opening, so that the rolling element rotates in the cavity between the guard plate 12 and the fixed shell 4. During use, the setting of the fixed shell 4 not only facilitates the disassembly and replacement of the rolling element, but also reduces the entry of formation debris into the gap between the rolling element and the mounting groove, which can ensure that the rolling element can continue to rotate during drilling.

[0029] Example 3: As an optimization of the above embodiment, as shown in the attached Figures 1 to 4 As shown, the rolling body includes three first support bodies 5 spaced apart along the length direction and a second support body 6 fixed between two adjacent first support bodies 5 .

[0030] According to requirements, the material of the first support body 5 is diamond, the material of the second support body 6 is cemented carbide, and the material of the second support body 6 can also be tungsten carbide. The material of the fixed shell 4 and the material of the guard plate 12 are both cemented carbide, which can improve the wear resistance of the fixed shell 4 and the guard plate 12. In order to facilitate the more firm fixation and bonding between the first support body 5 and the second support body 6, the two end faces of the second support body 6 can be arc surfaces with openings facing each other or the same openings. The end face of the first support body 5 matches the end face of the second support body 6, which can increase the contact area between the first support body 5 and the second support body 6, thereby enhancing the overall strength of the rolling body.

[0031] Example 4: As an optimization of the above embodiment, as shown in the attached Figure 1 、 2As shown in Figures 7 and 7, an auxiliary blade wing 7 is fixed on the outside of the drill body 1 between two adjacent main blade wings 2. The auxiliary blade wing 7 is divided into a second inner cone section, a second nose section, a second shoulder section, a second outer cone section and a second gauge section along the crown contour from the inside to the outside. A number of auxiliary cutting teeth 8 are arranged on the second inner cone section, the second nose section, the second shoulder section, the second outer cone section and the second gauge section of each auxiliary blade wing 7 from the inside to the outside. A chip groove 9 is formed between each auxiliary blade wing 7 and the main blade wing 2 at the adjacent position. A flushing cavity 10 is provided at the lower end of the drill body 1. At least one flushing hole 11 is distributed at intervals in each chip groove 9, and the other end of each flushing hole 11 is connected to the flushing cavity 10.

[0032] According to the needs, the number of main blades 2 and auxiliary blades 7 are both 3, or it can be a five-blade PDC drill bit structure consisting of 3 main blades 2 and 2 auxiliary blades 7. The auxiliary cutting teeth 8 have the same structure as the main cutting teeth 3 and are existing well-known PDC teeth. The auxiliary cutting teeth 8 can help the main cutting teeth 3 to bear part of the impact load, reduce the probability of drill bit vibration and cracking, and ensure the drilling speed of the drill bit during drilling. The flushing fluid can flush the mud and chips in the chip groove 9 in time through the flushing hole 11, reducing the resistance of the drill bit during drilling. An existing well-known nozzle is fixedly installed on the inner side of the upper end of each flushing hole 11.

[0033] In a specific embodiment, the sliding drill bit in the present application is a five-blade drill bit consisting of three main blades 2 and two auxiliary blades 7. Compared with the existing five-blade drill bit, the difference between this embodiment and the existing drill bit (model 8-3 / 4MMD55DC) is that a rolling body is added to the main blade 2. Both are set to run at a speed of 200 feet per hour and a rotation speed of 250 revolutions per hour. Compared in the deflection section, the performance of the sliding drill bit of the present application is improved by 9% to 10% compared with the existing drill bit. In order for the sliding drill bit of the present application and the existing drill bit to achieve the same drilling speed, a greater drilling pressure is required to drive the drill bit. The azimuth control effect of the sliding drill bit of the present application is better than that of the existing drill bit. In the test, as shown in the attached figure, Figure 8 As shown, compared with the existing drill bit's drilling speed of 95.5 feet per hour, the sliding drill bit in this application has a drilling speed of 104.9 feet per hour, a 10% increase in drilling speed, a 29% reduction in torque fluctuation, and a reduction in the average drilling time / curve per well from 13.8 hours to 8.4 hours.

[0034] As attached Figure 9As shown, the sliding drill bit of the present application is easier to maintain when in use than the control of the tool face of the existing drill bit, and its control range is more precise. It can run at a higher differential speed without sacrificing the accuracy of the tool face, and can maintain a higher drilling speed throughout the entire process from the start to reaching the target point. The existing drill bit needs to form a certain angle in the hole before applying a larger bit pressure, but with the sliding drill bit, a larger bit pressure can be applied to the drill bit from the beginning, so that drilling can start faster.

[0035] When drilling at 9534 feet downhole in 1-hole, the sliding drill bit of the present application maintained a drilling speed of 142.1 feet per hour. When drilling at 9630 feet downhole in 2-hole, the sliding drill bit of the present application maintained a drilling speed of 151.8 feet per hour. When drilling at 9530 feet downhole in 3-hole, the drilling speed of the existing drill bit was 121.9 feet per hour.

[0036] The above technical features respectively constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or removed according to actual needs to meet the requirements of different situations.

Claims

1. A sliding drill bit, characterized in that It includes a drill body and a rolling body. Several main cutting wings are evenly distributed along the circumference of the outer side of the upper part of the drill body. The main cutting wings are divided into a first inner cone section, a first nose, a first shoulder, a first outer cone section and a first gauge portion from the inside to the outside along the crown contour. Several main cutting teeth are arranged on the first inner cone section, the first nose, the first shoulder and the first outer cone section of each main cutting wing from the inside to the outside. In the counterclockwise direction, each first nose is provided with a mounting groove with an upward opening, and a rolling body is rotatably installed in the mounting groove. The rotation axis of the rolling body is set along the radial direction of the drill body, and the highest point of the rolling body is not higher than the highest point of the main cutting tooth on the first nose.

2. The sliding drill bit according to claim 1, characterized in that The rolling body is cylindrical, a fixed shell is fixedly installed on the inner side of the installation groove, and the outer side of the rolling body is sleeved on the inner side of the fixed shell.

3. The sliding drill bit according to claim 1 or 2, characterized in that The rolling body includes three first supporting bodies spaced apart along the length direction and a second supporting body fixed between two adjacent first supporting bodies.

4. The sliding drill bit according to claim 3, characterized in that The material of the first support body is diamond, and the material of the second support body is cemented carbide.

5. The sliding drill bit according to claim 1, 2 or 4, characterized in that An auxiliary blade is fixed on the outside of the drill body between two adjacent main blades. The auxiliary blade is divided into a second inner cone section, a second nose, a second shoulder, a second outer cone section and a second gauge section along the crown contour from the inside to the outside. A number of auxiliary cutting teeth are arranged on the second inner cone section, the second nose, the second shoulder, the second outer cone section and the second gauge section of each auxiliary blade from the inside to the outside. A chip groove is formed between each auxiliary blade and the main blade at the adjacent position. A flushing cavity is provided at the lower end of the drill body. At least one flushing hole is distributed at intervals in each chip groove, and the other end of each flushing hole is connected to the flushing cavity.

6. The sliding drill bit according to claim 3, characterized in that An auxiliary blade is fixed on the outside of the drill body between two adjacent main blades. The auxiliary blade is divided into a second inner cone section, a second nose, a second shoulder, a second outer cone section and a second gauge section along the crown contour from the inside to the outside. A number of auxiliary cutting teeth are arranged on the second inner cone section, the second nose, the second shoulder, the second outer cone section and the second gauge section of each auxiliary blade from the inside to the outside. A chip groove is formed between each auxiliary blade and the main blade at the adjacent position. A flushing cavity is provided at the lower end of the drill body. At least one flushing hole is distributed at intervals in each chip groove, and the other end of each flushing hole is connected to the flushing cavity.

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