Slip-on drill bit

Abstract

The present application relates to the technical field of drill bit, and is a sliding drill bit, which comprises a drill bit body and a rolling body. A plurality of main blades are uniformly distributed on the outer side of the upper part of the drill bit body along the circumference. The rolling body is located at the rear row of the main cutting teeth on the main blade, is at the highest position of the outer contour of the main blade, and is lower than the front row of the main cutting teeth. The setting of the rolling body can limit the excessive penetration of the main cutting teeth into the stratum, so that the main cutting teeth have a consistent penetration depth and provide a stable cutting depth. In this way, the vibration of the drill bit body can be reduced, the torque fluctuation can be reduced, and the friction between the main blade and the stratum can be reduced when the rolling body rolls on the stratum. On the basis of the single sliding plowing drilling mode of the drill bit body, the rolling and grinding effect is increased, the mechanical speed of the drill bit body is facilitated to be improved, and the drilling speed and drilling pressure are improved, and the control ability of the tool face is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drill bits, and is a sliding drill bit. BACKGROUND

[0002] A drill bit is a rock breaking tool used in drilling engineering to break rock and form a wellbore. The drill bit body has both fixed cutting structures and non-fixed cutting structures (such as a roller structure). A composite drill bit is a new type of rock breaking tool that has been gradually developed and widely applied in recent years. The composite drill bit uses the combined action of different cutting structures to break rock, and can significantly speed up drilling in some difficult-to-drill formations.

[0003] A composite drill bit with a steering wheel disc is disclosed in Chinese patent document CN106368615A. The composite drill bit includes a drill bit body and a wheel disc. The wheel disc is provided with a gear ring. The wheel disc can rotate relative to the drill bit body. The drill bit body is provided with at least one steering wheel disc. The steering wheel disc is composed of a wheel disc and a steering seat. The steering seat is installed on the drill bit body through a rotating connection. The steering seat can rotate relative to the drill bit body. The wheel disc is installed on the steering seat through a rotating connection. The wheel disc can rotate relative to the steering seat. The rotational axis of the wheel disc is offset relative to the rotational axis of the steering seat. 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 rotational axis of the steering seat of the steering wheel disc near the center of the drill bit does not coincide with the axis of the drill bit. The drill bit body is also provided with fixed cutting structures or non-fixed cutting structures. The steering seat installed on the drill bit body can rotate in any direction. The main problem solved by this structure is the short service life of the wheel disc cutting teeth, and the rock breaking efficiency is improved. However, this structure is complex and is easily damaged when the bottom hole pressure is too large. When the drill bit is drilling in the bottom hole, excessive jumping and vibration of the drill bit can easily damage the structure. The wheel disc is subjected to various forces, and the direction of the wheel disc cannot be kept consistent with the direction of rotation of the drill bit body.

[0004] A PDC drill bit with disc knives and rotatable cutting teeth is disclosed in Chinese patent document CN117287123A. The PDC drill bit includes a drill bit body and a blade. The blade is provided on the drill bit body. At least one blade is provided with rotating teeth and disc knives. The rotating teeth include a central rotating tooth, a bushing, a rotating tooth rotating shaft, and a stopper. A first gear is provided on the rotating tooth rotating shaft. The central rotating tooth is in rotational connection with the bushing. The rotating tooth is fixed to the blade through the bushing. The disc knives include a disc and a disc shaft. A second gear is provided on the disc shaft. The disc knives are connected to the blade. The disc knives rotate. The rotating teeth and the disc knives are connected together through gear meshing. This drill bit mainly drives the front row of central rotating teeth to rotate through the rotating teeth on the side of the blade, thereby improving the service life of the diamond layer of the front row of central rotating teeth. However, since the front row of central rotating teeth is always rotating, the drill bit is prone to deviation, and the stability is poor.

[0005] A design method of a blade type PDC roller composite drill bit is disclosed in Chinese patent document CN117027659A. The method first obtains the shear strength and internal friction angle of the formation through field logging data, then determines the drill bit diameter according to the drilling conditions, and then determines the number of rollers according to the drill bit diameter, and uniformly distributes the rollers on different blades. Then, the radial position of the roller and the coverage area of the roller are determined according to the drill bit diameter and the internal friction angle of the formation. Finally, the axial inclination angle of the roller is determined according to the shear strength of the formation. The design method combines field test data, classification discussion and digital calculation to design the roller structure parameters of the composite drill bit. The composite drill bit designed by the design method is provided with rollers on the fixed blades, and does not play a role in limiting the cutting tooth penetration of the drill bit. SUMMARY

[0006] The present application provides a sliding drill bit, which overcomes the shortcomings of the prior art and effectively solves the problems of easy vibration, large torque fluctuation, and inability to improve drilling speed and drilling pressure during drilling of the existing drill bit.

[0007] The technical scheme of the present application is realized by the following measures: a sliding drill bit, comprising a drill bit body and a rolling body, a plurality of main blades are uniformly distributed on the outer side of the upper part of the drill bit body along the circumference, the main blades are divided into a first inner cone section, a first nose, a first shoulder, a first outer cone section and a first gauge section along the crown profile from inside to outside, 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 blade from inside to outside, and along the counterclockwise direction, an installation slot opening upward is arranged on each first nose, the rolling body is rotatably installed in the installation slot, 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 is a further optimization or / and improvement of the above-mentioned technical scheme:

[0009] The rolling body can be cylindrical, and a fixed shell is fixedly installed on the inner side of the installation slot, and the rolling body is sleeved on the inner side of the fixed shell.

[0010] The rolling body can include three first support bodies arranged at intervals along the length direction and a second support body fixed between the adjacent two first support bodies.

[0011] The material of the first support body can be diamond, and the material of the second support body can be hard alloy.

[0012] The drill bit body outside of the position between the two adjacent main blades can be fixed with a secondary blade, the secondary blade is sequentially divided into a second inner taper section, a second nose, a second shoulder, a second outer taper section and a second gage section along the crown profile from inside to outside, a plurality of secondary cutting teeth are arranged on the second inner taper section, the second nose, the second shoulder, the second outer taper section and the second gage section of each secondary blade from inside to outside at intervals, a chip groove is formed between each secondary blade and the adjacent position of the main blade, and the lower end of the drill bit body is provided with a flushing cavity.

[0013] The structure of the present application is ingenious, the rolling body is located in the rear row of the main cutting teeth on the main blade, is at the highest position of the outer profile of the main blade, is lower than the front row of the main cutting teeth, the setting of the rolling body can limit the excessive cutting of the main cutting teeth into the stratum, so that the main cutting teeth have a consistent cutting depth, and a stable cutting depth is provided, so that the vibration of the drill bit body can be reduced, the torque fluctuation is reduced, and the friction between the main blade and the stratum can be reduced when the rolling body rolls on the stratum, so that the rolling grinding effect is increased on the basis of the single sliding plowing drilling mode of the drill bit body, the mechanical rotation speed of the drill bit body is facilitated to be improved, and the drilling speed and the drilling pressure are improved, and the control ability of the tool face is improved. BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG. 1 is a front view of the structure of the present application. Figure 1 FIG. 2 is a front view of the structure of the present application.

[0015] FIG. 3 is a front view of the structure of the present application. Figure 2 FIG. 4 is a front view of the structure of the present application.

[0016] FIG. 5 is a front view of the structure of the present application. Figure 3 FIG. 6 is a front view of the structure of the present application.

[0017] FIG. 7 is a front view of the structure of the present application. Figure 4 FIG. 8 is a front view of the structure of the present application.

[0018] FIG. 9 is a front view of the structure of the present application. Figure 5 FIG. 10 is a front view of the structure of the present application.

[0019] FIG. 11 is a front view of the structure of the present application. Figure 6 FIG. 12 is a front view of the structure of the present application.

[0020] FIG. 13 is a front view of the structure of the present application. Figure 7 FIG. 14 is a front view of the structure of the present application.

[0021] FIG. 15 is a front view of the structure of the present application. Figure 8 FIG. 16 is a front view of the structure of the present application.

[0022] FIG. 17 is a front view of the structure of the present application.Figure 9 This is a comparison chart of drilling speed and drilling pressure at different depths between Embodiment 4 of the present invention and existing drill bits.

[0023] The codes in the attached diagram are as follows: 1 is the drill bit 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 secondary blade, 8 is the secondary cutting tooth, 9 is the chip removal groove, 10 is the flushing chamber, 11 is the flushing hole, and 12 is the guard plate. Detailed Implementation

[0024] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0025] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0026] The present invention will be further described below with reference to embodiments and accompanying drawings:

[0027] Example 1: As shown in the attached document Figure 1 , 2 As shown in Figure 6, the sliding drill bit includes a drill body 1 and a rolling element. Several main cutting wings 2 are evenly distributed around the upper outer side of the drill body 1. The main cutting wings 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 diameter-protecting section from the inside to the outside along the crown contour. Several main cutting teeth 3 are arranged 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 cutting wing 2. In the counterclockwise direction, each first nose section is provided with an upward-opening mounting groove. The rolling element is rotatably mounted in the mounting groove. The rotation axis of the rolling element is set along the radial direction of the drill body 1. The highest point of the rolling element is not higher than the highest point of the main cutting teeth 3 on the first nose section.

[0028] The rolling element is located behind the main cutting teeth 3 on the main blade 2, at the highest point of the outer contour of the main blade 2, and lower than the front row of main cutting teeth 3. The rolling element can limit the main cutting teeth 3 from excessively penetrating the formation, so that the main cutting teeth 3 have a consistent penetration depth and provide a stable cutting depth. This can reduce the vibration of the drill bit body 1 and reduce torque fluctuation. When the rolling element 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 the single sliding plowing drilling method, which makes it easier to increase the mechanical speed of the drill bit body 1, thereby increasing the drilling speed and drilling pressure, and improving the control capability of the tool face.

[0029] The sliding drill bit can be further optimized or improved according to actual needs:

[0030] Embodiment two: as an optimization of the above embodiments, as shown in FIGS. Figure 1 , 2 , the rolling body is cylindrical, and the fixed shell 4 is fixedly installed on the inner side of the installation slot.

[0031] According to requirements, the fixed shell 4 can have an open box structure at the upper portion, the width of the opening is less than the diameter of the rolling body, the depth of the fixed shell 4 is greater than the radius of the rolling body and less than the diameter of the rolling body, that is, the cross section of the cavity on the inner side of the fixed shell 4 is an arc, in order to facilitate the installation of the rolling body, the width of the opening can also be set to be greater than the diameter of the rolling body, and then an arc-shaped guard plate 12 is fixedly installed on the inner side of the rear portion of the fixed shell 4 in the counterclockwise direction, the guard plate 12 is sleeved on the outer side of the rear portion of the rolling body, so that the thickness of the guard plate 12 can reduce the width of the opening, so that the rolling body rotates in the cavity between the guard plate 12 and the fixed shell 4. During use, the arrangement of the fixed shell 4 facilitates the disassembly and replacement of the rolling body, and also reduces the entry of formation debris into the gap between the rolling body and the installation slot, so as to ensure that the rolling body can continuously rotate during drilling.

[0032] Embodiment three: as an optimization of the above embodiments, as shown in FIGS. Figures 1 to 4 , the rolling body includes three first support bodies 5 arranged at intervals along the length direction and a second support body 6 fixed between adjacent two first support bodies 5.

[0033] According to requirements, the material of the first support body 5 is diamond, the material of the second support body 6 is hard alloy, 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 hard alloy, so as to improve the wear resistance of the fixed shell 4 and the guard plate 12. In order to facilitate the fixed bonding between the first support body 5 and the second support body 6 to be more firm, the two end faces of the second support body 6 can be arc faces with opposite openings or the same opening, the end face of the first support body 5 matches the end face of the second support body 6, so as to increase the contact area between the first support body 5 and the second support body 6, thereby enhancing the strength of the whole rolling body.

[0034] Embodiment four: as an optimization of the above embodiments, as shown in FIGS. Figure 1 , 2, 7, the drill bit body 1 outside the position between the two adjacent main blades 2 is fixed with a secondary blade 7, the secondary blade 7 is divided into a second inner taper section, a second nose, a second shoulder and a second outer taper section and a second gauge section along the crown profile from inside to outside, and a plurality of secondary cutting teeth 8 are arranged on the second inner taper section, the second nose, the second shoulder and the second outer taper section and the second gauge section of each secondary blade 7 from inside to outside, and a junk slot 9 is formed between each secondary blade 7 and the adjacent position of the main blade 2, and the lower end of the drill bit body 1 is provided with a flushing cavity 10, and at least one flushing hole 11 is arranged in each junk slot 9, and the other end of each flushing hole 11 is communicated with the flushing cavity 10.

[0035] According to the needs, the number of main blades 2 and secondary blades 7 is 3, and the five-blade PDC drill bit structure composed of 3 main blades 2 and 2 secondary blades 7 can also be used, the secondary cutting teeth 8 and the main cutting teeth 3 have the same structure, which are the existing known PDC teeth, the secondary cutting teeth 8 can help the main cutting teeth 3 bear part of the impact load, reduce the probability of drill bit vibration and collapse, ensure the drilling speed of the drill bit when drilling, and the flushing liquid can flush the cuttings in the junk slot 9 in time through the flushing hole 11, reduce the resistance when the drill bit drills, and the upper end of each flushing hole 11 is fixedly installed with a nozzle known to the prior art.

[0036] In a specific embodiment, the sliding drill bit in the present application is a five-blade drill bit composed of 3 main blades 2 and 2 secondary blades 7. Compared with the existing five-blade drill bit, the difference between the present embodiment and the existing drill bit (model 8-3 / 4MMD55DC) is only that a rolling body is added to the main blade 2, and both are set to run at a speed of 200 feet per hour and a rotation speed of 250 revolutions per hour. In the build-up 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 to achieve the same drilling speed, the sliding drill bit of the present application needs greater drilling pressure 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 figure, Figure 8 , the drilling speed of the sliding drill bit in the present application is 104.9 feet per hour, which is 10% higher than the drilling speed of 95.5 feet per hour of the existing drill bit, and the torque fluctuation is reduced by 29%, and the average drilling time / curve of each well is shortened from 13.8 hours to 8.4 hours.

[0037] As shown in the figure, Figure 9As shown, the sliding drill bit of the present application is easier to maintain and more accurate in control relative to the prior art drill bit tool face, can operate at a higher differential rate without sacrificing tool face accuracy, can maintain a higher drilling rate throughout the entire process from start to target point, while the prior art drill bit needs to form a certain angle in the hole to apply a larger drilling pressure, but using the sliding drill bit, a larger drilling pressure can be applied on the drill bit from the beginning, so that drilling can be started faster.

[0038] The drilling rate of the sliding drill bit of the present application is maintained at 142.1 feet per hour when drilling at 9534 feet downhole in well 1, at 151.8 feet per hour when drilling at 9630 feet downhole in well 2, and at 121.9 feet per hour when drilling at 9530 feet downhole in well 3.

[0039] The above technical features respectively constitute embodiments of the present application, which have strong adaptability and implementation effect, and unnecessary technical features can be added or reduced according to actual needs to meet the needs of different situations.

Claims

1. A sliding bit characterized by The drill bit comprises a drill bit body and rolling bodies. A plurality of main blades are uniformly distributed on the outer side of the upper part of the drill bit body along the circumference. The main blades are divided into a first inner taper section, a first nose, a first shoulder, a first outer taper section and a first gage section along the crown profile from inside to outside. A plurality of main cutting teeth are arranged on the first inner taper section, the first nose, the first shoulder and the first outer taper section of each main blade from inside to outside. In the counterclockwise direction, each first nose is provided with an upwardly open mounting groove. The rolling bodies are rotatably mounted in the mounting grooves. The rotation axis of the rolling bodies is arranged along the radial direction of the drill bit body. The highest point of the rolling bodies is not higher than the highest point of the main cutting teeth on the first nose. The rolling bodies are cylindrical. A fixed shell is fixedly installed on the inner side of the mounting groove. The rolling bodies are sleeved on the inner side of the fixed shell. The rolling bodies comprise three first support bodies arranged at intervals along the length direction and a second support body fixed between the adjacent two first support bodies.

2. The sliding bit of claim 1 wherein The material of the first support bodies is diamond. The material of the second support body is hard alloy.

3. The slide bit of claims 1 or 2, wherein A secondary blade is fixed on the outer side of the drill bit body between the adjacent two main blades. The secondary blade is divided into a second inner taper section, a second nose, a second shoulder, a second outer taper section and a second gage section along the crown profile from inside to outside. A plurality of secondary cutting teeth are arranged on the second inner taper section, the second nose, the second shoulder, the second outer taper section and the second gage section of each secondary blade from inside to outside. A chip groove is formed between each secondary blade and the adjacent main blade. A flushing cavity is arranged at the lower end of the drill bit body. At least one flushing hole is arranged in each chip groove. The other end of each flushing hole is in communication with the flushing cavity.

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