A roller reamer for oilfield drilling

Abstract

A roller reamer for oilfield drilling, relating to the field of oilfield drilling tools, includes a connecting body, a roller shaft, a roller, a shaft seat, a connecting bolt, a connecting disc, and a locking sleeve. Two shaft seats are respectively connected and installed in slots opened on the connecting body using connecting bolts. The roller shaft is connected between the shaft seats, and the roller is fitted on the roller shaft. The head of the connecting bolt has a transverse groove. The connecting disc and the locking sleeve are sequentially installed in the bolt connection hole. An upper key pin and a lower key pin are respectively provided on the upper and lower end faces of the connecting disc. The lower key pin corresponds to and fits into the transverse groove. The inner circumferential surface of the locking sleeve has a reverse thread, and the bottom end has a limiting groove that corresponds to and fits into the upper key pin. A strip-shaped sawtooth ridge is provided in the bolt connection hole. The locking sleeve is interference-fitted and impact-embedded into the bolt connection hole, establishing a sawtooth meshing fit with the shaft seat. This can limit and constrain the connecting bolt in the axial direction and also rotate and constrain the connecting bolt in the circumferential direction, strengthening the locking effect on the connecting bolt and improving the locking effect.

Description

Technical Field

[0001] This utility model relates to the field of oilfield drilling tools, specifically to a roller reamer for oilfield drilling. Background Technology

[0002] Oil well reamers are an important downhole tool used in oilfield drilling production. They are mainly used to ream and enlarge the wellbore using roller-mounted cutting elements. Based on the structure and working method of the cutting elements, they can be divided into roller reamers and blade reamers. Among them, roller reamers have been widely used in oilfield production due to their wide applicability to formations and their ability to stabilize the drill string. Utility model patent CN204266917U discloses a "bidirectional roller reamer". This utility model uses a bolt connection to fix the roller end seats to the roller body and sets a retaining ring to prevent the bolts from falling off. Although it simplifies the connection structure, the retaining ring can only limit the bolt axially. During production and use, the vibration of the drill bit can easily cause the bolts to rotate and loosen, reducing the stability of the connection between the roller end seats and the roller body, and reducing the reaming effect. Continuous vibration and impact between the roller end seats and the roller body may also cause bolt fatigue fracture, resulting in production accidents. In particular, the retaining ring is connected to the roller end seats by welding. When replacing the roller end seats, the retaining ring must be destructively removed first, which obviously still involves high labor intensity. The existing roller reamer suffers from several drawbacks. Firstly, it has low disassembly efficiency and is prone to damaging the roller end seat, shortening its service life and increasing production costs. Secondly, while the rolling steel balls and oil lubrication structure between the roller and roller shaft reduce friction and wear, the overall surface contact between them, coupled with the pressure of the unbalanced drilling mud, still results in significant frictional resistance. This excessive resistance not only drastically reduces the smoothness of the roller's rotation relative to the roller shaft, further affecting the reaming function, but also increases the tendency for frictional wear and damage between the roller and roller shaft, thus requiring further improvement in the reamer's service life. Therefore, it is necessary to conduct targeted research and improvement on the existing roller reamer to better adapt to the characteristics of the oilfield production environment and drilling process requirements, and to solve the existing technical problems. Utility Model Content

[0003] The purpose of this utility model is to provide a roller reamer for oilfield drilling, which improves the product structure to meet the characteristics of the oilfield production environment and the requirements of drilling production processes, enhances the operating efficiency of the roller reamer, and improves production efficiency.

[0004] A roller reamer for oilfield drilling includes: a connecting body, a roller shaft, a roller, a bearing seat, connecting bolts, a connecting disc, and a locking sleeve. The connecting body is a structure that connects to a tubing string. A mounting groove is formed on the connecting body, and the mounting grooves are evenly distributed along the circumference of the connecting body. Two bearing seats are axially correspondingly arranged and connected to the mounting grooves by the connecting bolts. The roller shaft is fixedly connected between the two corresponding bearing seats. The roller shaft is parallel to the axis of the connecting body. The roller is fitted onto the roller shaft and can rotate about the roller shaft as its axis. The outer circumference of the roller shaft... The upper and outer surfaces of the shaft seat are respectively fixedly inlaid with regularly arranged alloy pillars; a radially penetrating transverse groove is opened at the head of the connecting bolt. The connecting disc and the locking sleeve correspond to the bolt connection hole structure opened on the shaft seat and are sequentially fitted in the bolt connection hole. The connecting disc is a disc structure, and an upper key pin and a lower key pin are respectively provided on the upper and lower end faces of the disc. The lower key pin corresponds to the transverse groove structure opened on the head of the connecting bolt and establishes an inlay fit. The locking sleeve is a circular sleeve body, with a reverse thread opened on the inner circumference surface, and limit grooves are opened on both radial sides of the bottom end. The limit grooves are on the upper end face of the connecting disc. The key pin structures correspond to each other and establish an insert fit. A strip-shaped sawtooth edge, axially distributed along the circumference, is provided on the inner circumferential surface of the bolt connection hole. The locking sleeve is made of a metal material with a lower hardness than the bearing seat. It is inserted into the bolt connection hole with an interference fit impact. During the insertion process, the strip-shaped sawtooth edge can create grooves on the outer circumferential surface of the locking sleeve, forming a sawtooth meshing fit between the locking sleeve and the bearing seat. This restricts the rotation of the locking sleeve relative to the bearing seat, enhances the fitting strength of the locking sleeve in the bolt connection hole, and prevents the connecting bolt from loosening or even falling off under continuous vibration conditions. When disassembling the bearing seat, simply screw the threaded rod corresponding to the reverse thread structure on the inner circumference of the locking sleeve into the central shaft hole of the locking sleeve. Since the locking sleeve cannot rotate relative to the bearing seat due to the serrated meshing structure, after the threaded rod is fully screwed in and abuts against the connecting plate, continue to rotate the threaded rod to move the locking sleeve upward along the threaded rod until it disengages from the bolt connection hole. Then, remove the connecting plate and rotate to remove the connecting bolt to remove the bearing seat from the connecting body. The disassembly process is simple and reliable. Using special matching tools can also reduce labor intensity and improve work efficiency.

[0005] The aforementioned oilfield drilling roller reamer further includes: steel balls and needle rollers. The steel balls are fitted into a circular annular groove formed by the combination of the roller and the roller shaft, allowing the roller to be axially limited. The steel balls are fitted onto the roller shaft to prevent the upper and lower end faces of the roller from contacting the shaft seat, which could increase frictional resistance during rotation. Simultaneously, the needle rollers are fitted into a rectangular annular groove on the roller shaft between the roller and the roller shaft. The needle rollers and steel balls are correspondingly arranged and cooperate to balance and support the spatial state of the roller relative to the roller shaft. The point contact between the steel balls and the roller and the line contact between the needle roller and the roller completely replace the surface contact between the roller shaft and the roller. This transforms the sliding friction between the roller and the roller shaft into rolling friction between the roller and the needle roller, significantly reducing frictional resistance during roller rotation, minimizing wear and damage to components, increasing service life, and saving production costs.

[0006] The aforementioned roller reamer for oilfield drilling preferably has rubber sealing rings installed between the mating surfaces of the roller and the roller shaft at both ends. These sealing rings seal the corresponding mating areas between the inner circumferential surface of the roller and the outer circumferential surface of the roller shaft, and fill the sealed areas with lubricating oil. This further reduces the rotational frictional resistance of the roller relative to the roller shaft, while preventing downhole circulating mud from seeping into the area between the roller and the roller shaft, which could adversely affect the dynamic fit between the roller and the roller shaft, damage the components, and reduce working efficiency.

[0007] The aforementioned roller reamer for oilfield drilling preferably has a pressure balance hole on the roller shaft. The pressure balance hole connects the enclosed area between the roller and the roller shaft to the external environment of the roller. A balance piston is sealed inside the pressure balance hole. Based on sealing the enclosed area, the pressure between the enclosed area filled with lubricating oil and the external environment filled with circulating mud can be dynamically balanced by the adaptive displacement of the balance piston. This eliminates the additional impact of the circulating mud pressure on the dynamic fit between the roller and the roller shaft, ensuring reaming efficiency and improving working efficiency.

[0008] The aforementioned roller reamer for oilfield drilling preferably has a sealing cap on the bolt connection hole port on the shaft seat, which is fixed by a retaining ring. The sealing device includes the connecting plate and the locking sleeve on the bolt connection hole, preventing circulating mud and other substances from accumulating in the central shaft hole of the locking sleeve during production and use, thus hindering the threaded engagement between the threaded rod and the locking sleeve, increasing the difficulty of removing the locking sleeve, and making the disassembly of the shaft seat more difficult.

[0009] The beneficial effects of this utility model are that it provides a roller reamer for oilfield drilling. Combined with the actual production needs of oilfields, it uses a combination structure of a connecting disc and a locking sleeve to fix and lock the connecting bolts. It not only uses the interference fit of the locking sleeve to set axial limiting constraints on the connecting bolts, but also uses the serrated meshing between the locking sleeve and the shaft seat to set rotational constraints on the connecting bolts in the circumferential direction. This strengthens the fixing and locking effect of the connecting bolts, improves the fixing and locking effect, and enhances the reliability of the connection between the shaft seat and the connecting body. In particular, the locking sleeve can be easily removed from the shaft seat by simply using a corresponding threaded rod for rotation, making the removal process simple, convenient, and labor-saving. With low friction and high disassembly efficiency, it helps improve oilfield production efficiency. Furthermore, by setting up a needle roller support structure, which works together with the steel ball connection structure, the point contact fit between the steel ball and the roller and the line contact fit between the needle roller and the roller completely replace the surface contact fit between the roller shaft and the roller. A rolling friction fit in the form of steel ball point contact and needle roller line contact is established between the roller and the roller shaft, replacing the sliding friction form of surface contact between the roller and the roller shaft. This can significantly reduce the frictional resistance under the roller rotation condition, reduce the wear and damage of the roller and roller shaft during production, improve the service life of the roller assembly, save production cost input, and meet production needs. Attached Figure Description

[0010] Figure 1 This is a structural diagram of a roller reamer used in oilfield drilling.

[0011] Figure 2 This is the main view of the roller assembly structure.

[0012] Figure 3 for Figure 2 Enlarged view of a portion of the roller assembly at point I.

[0013] Figure 4 for Figure 2 Cross-sectional view of the middle roller assembly AA.

[0014] Figure 5 for Figure 2 Cross-sectional view of the middle roller assembly BB.

[0015] Figure 6 for Figure 2 Single-sided sectional view of the middle roller assembly (CC).

[0016] Figure 7 This is a right view of the roller assembly structure.

[0017] Wherein: 1 is the connecting body, 2 is the roller shaft, 3 is the roller, 4 is the shaft seat, 5 is the connecting bolt, 6 is the connecting disc, 7 is the locking sleeve, 8 is the alloy column, 9 is the steel ball, 10 is the needle roller, 11 is the rubber sealing ring, 12 is the pressure balance hole, 13 is the balance piston, 14 is the sealing cover, 15 is the elastic retaining ring, 16 is the spring, 17 is the bolt plug, 18 is the ball plug, 19 is the threaded pin, and 20 is the roller assembly. Detailed Implementation

[0018] Furthermore, the technical solution for which protection is sought in this utility model will be described in detail below with reference to specific embodiments and accompanying drawings.

[0019] A roller reamer for oilfield drilling, such as Figure 1 As shown, it consists of a connecting body 1 and a roller assembly 20 connected and mounted on the connecting body 1. The roller assembly 20 is as follows: Figures 2 to 7 As shown, it consists of roller shaft 2, roller 3, shaft seat 4, connecting bolt 5, connecting disc 6, locking sleeve 7, steel ball 9, needle roller 10, balance piston 13, sealing cover 14, elastic retaining ring 15, spring 16 and bolt plug 17.

[0020] The upper and lower ends of the connecting body 1 are respectively provided with internal and external threads for interconnection with the pipe column. Three evenly distributed mounting slots are formed on the circumferential surface for mounting the roller assembly 20. Two bearing seats 4 are correspondingly arranged along the axial direction of the connecting body 1 in each mounting slot and are respectively fixed to the connecting body 1 using connecting bolts 5. The two ends of the roller shaft 2 are respectively fixedly connected to the two bearing seats 4 using threaded pins 19. The threaded pins 19 are internally threaded cylindrical pins, ensuring that the axis of the roller shaft 2 is parallel to the axis of the connecting body 1. The roller shaft 2 has an outer semi-circular annular groove in the middle of its outer circumference. Two symmetrically arranged rectangular annular grooves are formed in the upper and lower regions of the semi-circular annular groove. An inner semi-circular annular groove corresponding to the outer semi-circular annular groove is formed on the inner circumference of the roller 3. A process hole is also formed, penetrating the sidewall of the roller 3 and connecting to the inner semi-circular annular groove, for filling steel balls. The roller 3 is mounted on the roller shaft 2. Vertically arranged needle rollers 10 are inserted and filled into the two rectangular annular grooves, maintaining the corresponding combination of the outer and inner semi-circular annular grooves. A complete circular groove is formed, and the steel balls 9 are inserted into the circular groove and the process hole is sealed with ball plugs 18, so that the roller 3 is hooked onto the roller shaft 2. Alloy pillars 8 are fixedly embedded on the outer circumferential surface of the roller shaft 2 and on the outer side of the bearing seat 4 protruding from the outer circumferential surface of the connecting body 1, respectively. Rubber sealing rings 11 are respectively installed between the upper and lower ends of the roller 3 and the mating surfaces of the roller shaft 2 to seal the corresponding mating areas between the roller 3 and the roller shaft 2. The sealed areas are filled with lubricating oil, and the lubricating oil is selected from The composite lithium-based grease has pressure balance holes 12 on the upper and lower end faces of the roller shaft 2, which are connected to the closed area. The pressure balance hole 12 on the upper end face is a lubricating oil filling observation port, which can be sealed with a bolt plug 17. The balance piston 13 is sealed and embedded in the pressure balance hole 12 on the lower end face to maintain a dynamic balance between the internal pressure of the closed area and the external environmental pressure. At the same time, a spring 16 is provided between the balance piston 13 and the roller shaft 2 to buffer the movement of the balance piston 13.

[0021] The connecting bolt 5 is an internal hexagon head bolt with a radially through transverse groove on its head. The connecting disc 6, the locking sleeve 7, and the sealing cover 14 correspond to the bolt connection hole structure on the bearing seat 4 and are sequentially fitted into the bolt connection hole connected to the connecting bolt 5. The inner circumferential surface of the bolt connection hole is provided with axially evenly distributed strip-shaped sawtooth ridges. The upper and lower end faces of the connecting disc 6 are respectively provided with a cross-shaped upper key pin and a lower key pin. The inner circumferential surface of the locking sleeve 7 is provided with a reverse thread, and the bottom radial sides are respectively provided with... The lower key pin on the lower end face of the connecting disc 6 is fitted into the transverse groove on the head of the connecting bolt 5, and the upper key pin on the upper end face is fitted into the limiting groove on the bottom end of the locking sleeve 7. The locking sleeve 7 is made of a metal material with a hardness lower than that of the bearing 4, and is embedded into the bolt connection hole in an interference fit manner. After being toothed by the strip-shaped sawtooth groove, it forms a sawtooth meshing state with the bearing 4. The sealing cover 14 is placed on the locking sleeve 7, which completely seals and covers the bolt connection hole and is fixed by the elastic retaining ring 15.

[0022] The method for assembling and installing the roller assembly 20 onto the connecting body 1 in this embodiment is as follows: First, fill the rectangular annular groove on the roller shaft 2 with roller needles 10 and fit rubber sealing rings 11 at both ends. Then, fit the roller 3 onto the roller shaft 2 and adjust the fitting position of the roller 3 so that both ends of the roller 3 form a sealing fit with the roller shaft 2. At the same time, align the inner semi-circular annular groove on the roller 3 with the outer semi-circular annular groove on the roller shaft 2 to form a circular annular groove. Then, fill the circular annular groove with steel balls sequentially through the process holes opened on the roller 3. 9. After filling, use ball plug 18 to seal the process hole, connect the roller 3 to the roller shaft 2 through the steel ball connection structure, and maintain a stable point contact and line contact rolling friction fit structure between the roller 3, the steel ball 9, and the needle roller 10; then, inject composite lithium-based grease into the pressure balance hole 12 opened on the lower end face of the roller shaft 2, and observe the pressure balance hole 12 opened on the upper end face of the roller shaft 2 while injecting. When the composite lithium-based grease overflows from the upper end face of the roller shaft 2, it indicates that the composite lithium-based grease has filled the entire process hole. In the enclosed area, the pressure balance hole 12 on the upper end face of the roller shaft 2 is sealed with bolt plug 17, and a balance piston 13 and spring 16 are installed in the pressure balance hole 12 on the lower end face of the roller shaft 2. Then, threaded pins 19 are used to fix the corresponding bearing seats 4 at both ends of the roller shaft 2. Then, connecting bolts 5 are used to fix the two bearing seats 4 in a groove opened on the connecting body 1. After ensuring that the connecting bolts 5 are fully tightened, the lower key pin on the connecting plate 6 is connected to the connecting bolts 5. Align the horizontal groove on the head, install the connecting plate 6 in the bolt connection hole, so that the lower key pin and the horizontal groove form an interlocking fit. Then align the limiting groove on the locking sleeve 7 with the upper key pin on the connecting plate 6, and impact the locking sleeve 7 into the bolt connection hole, so that the upper key pin and the limiting groove form an interlocking fit. After the locking sleeve 7 is fully inserted into the bolt connection hole, cover and place the sealing cover 14 on the locking sleeve 7, and use the elastic retaining ring 15 to limit and fix it. This completes the assembly and installation operation of the roller assembly 20 in one of the inserting grooves.After assembling and installing the roller assembly 20 in the other two mounting slots according to the above operating steps, the assembly of the oilfield drilling roller reamer described in this embodiment is completed. During production and use, the oilfield drilling roller reamer can be connected to the tubing using the connecting threads at both ends of the connecting body 1. It can then be run down the well for wellbore finishing or enlargement operations. When it is necessary to disassemble the roller assembly 20 from the connecting body 1, simply remove the elastic retaining ring 15, remove the sealing cover 14, and use the threaded rod corresponding to the reverse thread structure on the inner circumference of the locking sleeve 7 to directly rotate and pull the locking sleeve 7 out of the bolt connection hole. The operation method is simple, and using the matching tools can reduce labor intensity and improve work efficiency. Finally, remove the connecting disc 6 from the bolt connection hole and remove the connecting bolt 5 to remove one of the bearing seats 4 from the connecting body 1. Once both corresponding bearing seats have been removed, the disassembly operation of the roller assembly 20 is completed.

Claims

1. A roller reamer for oilfield drilling, characterized in that, include: The connection body (1), roller shaft (2), roller (3), bearing seat (4), connecting bolt (5), connecting disc (6), and locking sleeve (7) are included. The connecting body (1) is a structure that connects to the pipe column. A mounting groove is provided on the connecting body (1). The mounting groove is evenly distributed along the circumference of the connecting body (1). Two bearing seats (4) are axially correspondingly arranged and connected to the mounting groove by the connecting bolt (5). The roller shaft (2) is fixedly connected to the connecting body (1). The roller shaft (2) is parallel to the axis of the connecting body (1). The roller (3) is fitted onto the roller shaft (2) and can rotate around the roller shaft (2). Regularly arranged alloy columns (8) are fixedly embedded on the outer circumferential surface of the roller shaft (2) and the outer surface of the bearing seat (4). A radially penetrating transverse groove is provided at the head of the connecting bolt (5). The connecting disc (6) and the locking sleeve (7) The connecting disc (6) is a circular disc structure with an upper key pin and a lower key pin respectively provided on the upper and lower end faces of the disc. The lower key pin corresponds to the transverse groove structure provided on the head of the connecting bolt (5) and establishes an insert fit. The locking sleeve (7) is a circular sleeve with a reverse thread on the inner circumference surface and limit grooves provided on both radial sides of the bottom end. The limit grooves are connected to the connecting disc. (6) The upper key pin structures on the upper end face correspond to each other and establish an insert fit. A strip-shaped sawtooth edge is provided on the inner circumferential surface of the bolt connection hole. The locking sleeve (7) is made of a metal material with a hardness lower than that of the bearing seat (4). It is inserted into the bolt connection hole by interference fit impact. During the insertion process, the strip-shaped sawtooth edge can plow the outer circumferential surface of the locking sleeve (7) to form a sawtooth meshing fit between the locking sleeve (7) and the bearing seat (4).

2. The roller reamer for oilfield drilling as described in claim 1, characterized in that, Also includes: Steel balls (9) and needle rollers (10) are fitted together. The steel balls (9) are fitted into a circular groove formed by the combination of the roller (3) and the roller shaft (2), so that the roller (3) is axially limited. The steel balls are fitted into the roller shaft (2) to prevent the upper and lower end faces of the roller (3) from contacting the shaft seat (4) and thus increasing the frictional resistance during rotation. At the same time, the needle rollers (10) are fitted into a rectangular groove formed on the roller shaft (2) between the roller (3) and the roller shaft (2). The needle roller (10) and the steel ball (9) are arranged in a corresponding manner to cooperate and balance the spatial state of the roller (3) relative to the roller shaft (2). The point contact between the steel ball (9) and the roller (3) and the line contact between the needle roller (10) and the roller (3) are used to replace the surface contact between the roller shaft (2) and the roller (3). At the same time, the sliding friction between the roller (3) and the roller shaft (2) is transformed into the rolling friction between the roller (3) and the needle roller (10).

3. The roller reamer for oilfield drilling as described in claim 2, characterized in that: Rubber sealing rings (11) are respectively installed between the mating surfaces of the roller (3) and the roller shaft (2) at both ends, sealing the corresponding mating area between the inner circumferential surface of the roller (3) and the outer circumferential surface of the roller shaft (2) and filling the sealed area with lubricating oil.

4. The roller reamer for oilfield drilling as described in claim 3, characterized in that: A pressure balance hole (12) is provided on the roller shaft (2). The pressure balance hole (12) connects the closed area between the roller (3) and the roller shaft (2) with the external environment of the roller (3). A balance piston (13) is sealed in the pressure balance hole (12). Based on sealing the closed area, the pressure between the closed area filled with lubricating oil and the external environment filled with circulating mud can be dynamically balanced by the adaptive displacement of the balance piston (13).

5. A roller reamer for oilfield drilling as described in any one of claims 1 to 4, characterized in that: A cover (14) is provided on the bolt connection hole port opened on the bearing seat (4) and the bolt connection hole is limited and fixed by an elastic retaining ring (15). The sealing device includes the bolt connection hole of the connecting disc (6) and the locking sleeve (7).

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