Eccentric reamer for oil exploitation well drilling

Abstract

The utility model discloses an eccentric reamer for oil exploitation well drilling. The eccentric reamer comprises an upper connector, a reaming barrel, a screw rod, a lower connector and a reaming piece. According to the eccentric reamer provided by the utility model, the reaming piece is arranged on the outer edge of the reaming barrel, and the reaming piece and the rotary driving source (namely, the screw rod) are arranged on the same horizontal line, so that on one hand, the reaming piece is supported through the reaming barrel and the screw rod when the reaming piece is subjected to counter-acting force during rock wall cutting; the problem that the reaming piece is damaged due to large torque is improved and even avoided, the influence of the torque on the whole system is relieved, and the durability and reliability of the reamer are improved; on the other hand, the reaming piece and the screw are located on the same horizontal line, and the problem that the screw is bent or even broken due to the lever effect does not exist; meanwhile, the first flow channel, the first flow hole, the spiral containing cavity, the second flow hole and the second flow channel are formed, so that smooth circulation of the slurry serving as the driving fluid is guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of oil exploitation, in particular to an eccentric reamer used for oil exploitation drilling. Background Art

[0002] An eccentric underreamer is a tool used in oil drilling that is designed to change the size of a wellbore by rotating and expanding it eccentrically. It is typically used in horizontal wells or when sections of different diameters need to be created in the wellbore.

[0003] The invention patent application with application number 202110386113X discloses a composite rotary eccentric reaming tool, such as Figure 1 As shown, it consists of an upper joint 1, a rotor 2, a thrust bearing 3, an upper shell 4, a stator 5, a universal shaft 6, a middle shell 7, a transmission joint 8, an upper end cover 9, an O-ring Ⅰ10, a bearing Ⅰ11, a bearing seat 12, a lip seal 13, an upper eccentric ring 14, a lower shell 15, an upper spindle 16, a bearing Ⅱ17, a lower end cover 18, a middle joint 19, a lower spindle 20, a limiting cylinder 21, a spindle sleeve 22, a lower joint 23, a screw 24, a sealing cover 25, an eccentric drill bit 26, a set screw 27, a piston 28, a spring 29, a pressure cap 30, a transition joint 31 and a lower eccentric ring 32. The upper end of the upper joint 1 is provided with a thread, the lower end of the upper joint 1 is threadedly connected to the upper end of the upper shell 4, the lower end of the upper shell 4 is threadedly connected to the upper end of the middle shell 7, the lower end of the middle shell 7 is threadedly connected to the upper end of the lower shell 15, and the lower end of the lower shell 15 is threadedly connected to the upper end of the middle joint 19; the lower end of the rotor 2 is threadedly connected to the upper end of the universal shaft 6, the lower end of the universal shaft 6 is threadedly connected to the upper end of the transmission joint 8, the lower end of the transmission joint 8 is threadedly connected to the upper end of the upper spindle 16, the lower end of the upper spindle 16 is threadedly connected to the upper end of the lower spindle 20, and the lower end of the lower spindle 20 is threadedly connected to the upper end of the eccentric drill bit 26.

[0004] After the tool is connected, the center lines of the upper joint 1, the upper shell 4, the middle shell 7, the lower shell 15 and the middle joint 19 are located in a straight line, the center lines of the transmission joint 8, the upper spindle 16 and the lower spindle 20 are located in a straight line, and there is an eccentricity between the center lines of the upper joint 1, the upper shell 4, the middle shell 7, the lower shell 15 and the middle joint 19 and the center lines of the transmission joint 8, the upper spindle 16 and the lower spindle 20.

[0005] The invention patent application aims to use the wellhead rotary table to mechanically drive the lower eccentric drill bit to revolve, and then combine the hydraulic power to drive the lower eccentric shaft to drive the eccentric drill bit to rotate, so as to achieve the composite rotation movement of the eccentric drill bit revolving + rotating, so as to improve the hole expansion efficiency. However, in actual application, the resistance or friction encountered by the eccentric drill bit during hole expansion will generate a reaction force on the transmission structure such as the upper mandrel and the lower mandrel, and the reaction force will generate torque on the lever arm length on the transmission structure. Since the eccentric drill bit is far away from the driving source, the transmission structure is subjected to a large torque. If this torque exceeds the bearing capacity of the transmission structure, it will cause damage or failure of the transmission structure.

[0006] It can be seen that the existing technology still needs to be improved and perfected. Utility Model Content

[0007] In view of the above-mentioned deficiencies in the prior art, the purpose of the utility model is to provide an eccentric reamer for oil production and drilling, so as to improve the problem that the resistance or friction encountered by the existing eccentric reamer during reaming will generate a reaction force on structural parts such as the upper mandrel and the lower mandrel. Since the eccentric drill bit is far away from the driving source, the transmission structural parts are subjected to a large torque, which can easily lead to damage or failure of the transmission structural parts.

[0008] The technical solution of this utility model is as follows:

[0009] An eccentric reamer for oil production drilling, comprising:

[0010] An upper joint, wherein a first flow channel is opened in the middle of the upper joint, and the first flow channel is connected with at least one first flow hole;

[0011] An reaming cylinder, the reaming cylinder is connected to the upper joint, a spiral cavity connected to the first flow hole is opened in the middle, and the spiral cavity is eccentrically arranged relative to the first flow channel;

[0012] A screw rod, the screw rod is connected to the upper joint, is disposed in the spiral cavity, and is used to rotate under the drive of the fluid flowing out of the first flow hole and drive the reaming cylinder to rotate;

[0013] A lower joint, the lower joint is connected to the end of the reaming barrel away from the upper joint, is connected to the screw, and is provided with a second flow hole and a second flow channel for discharging fluid;

[0014] The reamer is arranged on the outer edge of the reamer barrel and is used for cutting the well wall to expand the hole.

[0015] The effect of the above scheme is that the eccentric reamer provided by the utility model sets the reaming piece on the outer edge of the reaming barrel and sets the reaming piece and the rotating driving source (i.e., the screw) on the same horizontal line. On the one hand, when the reaming piece is subjected to the reaction force when cutting the rock wall, the reaming piece is supported by the reaming barrel and the screw, thereby improving or even avoiding the problem of damage of the reaming piece due to large torque, reducing the influence of torque on the whole system, and improving the durability and reliability of the reamer; on the other hand, the reaming piece and the screw are on the same horizontal line, and there is no problem of the screw being bent or even broken due to the lever effect; at the same time, the utility model also ensures the smooth circulation of mud as the driving fluid by providing the first flow channel, the first flow hole, the spiral cavity, the second flow hole and the second flow channel.

[0016] In a further preferred embodiment, an upper wear-resistant sleeve is connected to one end of the upper joint facing the reaming cylinder, and / or an upper wear-resistant sleeve is connected to one end of the reaming cylinder facing the upper joint, and the upper wear-resistant sleeve forms a first gap between the upper joint and the reaming cylinder.

[0017] The effect of the above scheme is that the upper wear-resistant sleeve forms a first gap between the upper joint and the reaming barrel, which can reduce the direct contact between the two, reduce the wear caused by long-term friction, and extend the service life of the upper joint and the reaming barrel; moreover, the existence of the upper wear-resistant sleeve makes the relative movement between the upper joint and the reaming barrel more stable, reduces the irregular movement between the contact surfaces, improves the overall stability of the system, and ensures the reliability of the reamer under different working conditions; at the same time, the formation of the first gap also has the effect of preventing external substances such as mud or cutting debris from entering the connection between the upper joint and the reaming barrel, preventing equipment damage or performance degradation caused by foreign matter intrusion.

[0018] In a further preferred embodiment, the end of the upper joint facing the reaming cylinder is connected to a first upper wear-resistant sleeve, the end of the reaming cylinder facing the upper joint is connected to a second upper wear-resistant sleeve, and the first upper wear-resistant sleeve and the second upper wear-resistant sleeve are staggered and fitted together.

[0019] The effect of the above scheme is that the staggered fitting between the first upper wear-resistant sleeve and the second upper wear-resistant sleeve forms a double-layer wear-resistant protection structure, which further improves the wear resistance and durability of the connection between the upper joint and the reaming barrel, reduces the friction loss caused by the reaming operation, and further extends the life of the entire system; the staggered fitting of the first upper wear-resistant sleeve and the second upper wear-resistant sleeve creates a tighter combination, which can prevent mud or other external substances from entering the connection area between the upper joint and the reaming barrel, improves the sealing of the connection part, and can maintain the stable operation of the system; at the same time, through the staggered fitting of the first upper wear-resistant sleeve and the second upper wear-resistant sleeve, a more compact and optimized structural layout is achieved, which is not only conducive to the lightweight design of the overall equipment, but also improves the reliability and flexibility of the system.

[0020] In a further preferred embodiment, a lower wear-resistant sleeve is connected to one end of the lower joint facing the reaming cylinder, and / or a lower wear-resistant sleeve is connected to one end of the reaming cylinder facing the lower joint, and the lower wear-resistant sleeve forms a second gap between the lower joint and the reaming cylinder.

[0021] In a further preferred embodiment, the end of the lower joint facing the reaming cylinder is connected to a first lower wear-resistant sleeve, the end of the reaming cylinder facing the lower joint is connected to a second lower wear-resistant sleeve, and the first lower wear-resistant sleeve and the second lower wear-resistant sleeve are staggered and fitted together.

[0022] The effect of the above scheme is that the function and setting effect of the lower wear-resistant sleeve are the same as those of the upper wear-resistant sleeve (the first lower wear-resistant sleeve, the second lower wear-resistant sleeve and the first upper wear-resistant sleeve and the second upper wear-resistant sleeve are also the same), which will not be repeated.

[0023] In a further preferred embodiment, a plurality of protrusions are provided on the outer edge of the reaming barrel, a plurality of mounting holes are opened on the protrusions, and the reaming members are accommodated in the mounting holes in a one-to-one correspondence.

[0024] The effect of the above scheme is that the multiple protrusions on the outer edge of the reaming barrel provide multiple mounting holes, and different mounting holes can be selected for configuration according to specific needs (for example, different types and sizes of reamer pieces can be selected according to the geological conditions of the wellbore or working requirements), thereby realizing diversified configuration of the reamer performance; and the reamer pieces are accommodated in the mounting holes one by one, so that the installation position of the reamer piece can be adjusted relatively freely, so as to flexibly adjust the cutting position of the reamer piece according to actual conditions, adapt to the special requirements of different wellbore sections, and improve the applicability and cutting accuracy of the reamer; moreover, the setting of the mounting holes allows the reamer piece to be replaced and maintained relatively independently, which not only simplifies the operating steps of daily maintenance, but also reduces the system downtime and improves the maintainability of the reamer; by selecting the appropriate mounting hole configuration, efficient cutting of different wellbore formations can be achieved, which can maximize the cutting efficiency of the reamer and provide a more efficient and economical solution for drilling operations.

[0025] In a further preferred embodiment, a first inclined surface is arranged on one end of the protrusion facing the lower joint, and a plurality of eye-expanding members are arranged on the first inclined surface.

[0026] The effect of the above scheme is that the lower joint is closest to the drill bit, and the first bevel is also the part that is expanded first. By setting this part as the bevel, the expansion diameter of the eccentric reamer is gradually expanded, which reduces the resistance during cutting, reduces the friction between the reamer and the well wall, improves the cutting quality and cutting speed, reduces the energy consumption during cutting, and reduces the probability of damage to the reamer. Multiple reamer parts are arranged on the first bevel, which can adapt to cutting at different angles, so that the eccentric reamer can better adapt to different geological conditions or wellbore sections with special requirements, thereby improving the flexibility of work.

[0027] In a further preferred embodiment, a second inclined surface is arranged on one end of the protrusion facing the upper joint, and a plurality of eye expanders are arranged on the second inclined surface.

[0028] The effect of the above scheme is that when back-reaming is required, the second inclined surface will become the part that contacts the rock wall first. By setting this part as an inclined surface, the back-reaming diameter of the eccentric reamer is gradually expanded, which reduces the resistance during cutting, reduces the friction between the reamer and the well wall, improves the cutting quality and cutting speed, reduces the energy consumption during cutting, and reduces the probability of damage to the reamer. Multiple reamer parts are arranged on the second inclined surface, which can adapt to cutting at different angles during back-reaming, so that the eccentric reamer can better adapt to different geological conditions or wellbore sections with special requirements, thereby improving the flexibility of work.

[0029] In a further preferred embodiment, a plurality of protrusions are arranged at intervals along the outer edge of the reaming cylinder, and a side wall of the protrusion is a vertical surface, and a plurality of reaming members are arranged on the vertical surface.

[0030] The effect of the above scheme is that: by arranging the reamer on the side wall of the protrusion, the reamer, rather than the corner of the side wall, will first contact the rock wall, thereby providing protection for the protrusion; a plurality of reamers are arranged on the vertical surface of the protrusion, which, on the one hand, enables multi-point cutting to be performed simultaneously during the reaming process, reduces the load on each reamer, alleviates the resistance of single-point cutting, and improves the cutting effect; on the other hand, the uniform arrangement of the plurality of protrusions enables the reaming barrel to uniformly cut the well wall during rotation, thereby improving the cutting efficiency and uniformity; and the vertical surface of the protrusion provides additional support, reduces the vibration and swing of the reamer during the cutting process, enhances the stability of the entire eccentric reamer, and reduces the risk of damage that may be caused by unstable cutting.

[0031] In a further preferred embodiment, a smooth rod portion is provided on the side of the screw rod facing the lower joint, and a third gap is formed between the smooth rod portion and the inner wall of the reaming barrel.

[0032] The effect of the above scheme is that the existence of the third gap facilitates the flow of mud, ensuring that the mud can flow smoothly between the screw and the reaming barrel, ensuring the transmission of driving force and the normal operation of the reamer; at the same time, it also reduces the direct contact with the inner wall of the reaming barrel, effectively reduces the wear caused by friction during high-speed rotation, and extends the service life of the screw and the reaming barrel; at the same time, the design of the smooth rod makes the movement between the screw and the reaming barrel smoother, reduces vibration and noise, and improves the operating stability of the entire eccentric reamer.

[0033] In a further preferred embodiment, a frustoconical docking portion is provided on one end of the lower joint facing the screw rod, and a receiving groove adapted to the docking portion is provided on the screw rod.

[0034] The effect of the above scheme is that the frustum-shaped docking part can provide a larger guiding surface, so that the lower joint and the screw can be more easily aligned in precise position when docking, ensuring the normal coordination of various components of the reamer during operation; in addition, the design of the frustum-shaped docking part and the receiving groove makes the installation between the lower joint and the screw easier. When docking, it is only necessary to guide the docking part into the receiving groove to achieve fast and accurate assembly, thereby improving the installation efficiency; at the same time, the combination of the frustum-shaped docking part and the receiving groove provides a larger contact area, ensuring a firm connection between the lower joint and the screw, preventing looseness or swinging during operation, and improving the stability of the system; moreover, the frustum-shaped docking part can effectively transmit the load received during the reaming process, ensuring uniform distribution of force, and reducing unnecessary stress concentration on the connecting parts.

[0035] Compared with the prior art, the eccentric reamer for oil drilling provided by the utility model comprises: an upper joint, a reaming barrel, a screw, a lower joint and a reaming piece. The eccentric reamer provided by the utility model sets the reaming piece on the outer edge of the reaming barrel, and sets the reaming piece and the rotary drive source (i.e., the screw) on the same horizontal line. On the one hand, when the reaming piece is subjected to a reaction force when cutting the rock wall, the reaming piece is supported by the reaming barrel and the screw, thereby improving or even avoiding the problem of the reaming piece being damaged due to large torque, reducing the influence of torque on the entire system, and improving the durability and reliability of the reamer; on the other hand, the reaming piece and the screw are on the same horizontal line, and there is no problem of the screw being bent or even broken due to the lever effect; at the same time, the utility model also ensures the smooth circulation of mud as a driving fluid by providing a first flow channel, a first flow hole, a spiral cavity, a second flow hole and a second flow channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a structural schematic diagram of the compound rotary eccentric reaming tool published in 202110386113X.

[0037] Figure 2 The utility model is a cross-sectional view of an eccentric reamer used for oil production and drilling.

[0038] Figure 3 yes Figure 2 Enlarged view of part A in the figure.

[0039] Figure 4 The utility model is a structural schematic diagram of a reaming barrel used for an eccentric reamer used for oil production and drilling.

[0040] Figure 5 The utility model is a structural schematic diagram of an upper joint used for an eccentric eye reamer used for oil production and drilling.

[0041] Figure 6 The utility model is a structural schematic diagram of a lower joint used for an eccentric eye reamer used for oil production and drilling.

[0042] Figure 7 The utility model is a structural schematic diagram of a screw rod used in an eccentric reamer for oil production and drilling. DETAILED DESCRIPTION

[0043] The utility model provides an eccentric reamer for oil drilling. To make the purpose, technical solution and effect of the utility model clearer and more specific, the following specific implementation manner will further describe the utility model in detail with reference to the accompanying drawings and examples.

[0044] like Figure 1 In the prior composite rotary eccentric reaming tool shown, the eccentric drill bit at the lower end thereof is actually subjected to two different reaction forces when cutting the rock wall: one is the radial reaction force, that is, due to the cutting movement of the eccentric drill bit, the rock wall generates a radial reaction force on the eccentric drill bit, hindering the reaming movement of the eccentric drill bit. When the radial reaction force acts on the eccentric drill bit and the transmission structure, due to the lever effect, the upper and lower spindles are forced to tilt, squeezing the bearings sleeved on the outer edges of the two. The side effects are not obvious in the short term, but after a period of use, the bearings will be damaged or the upper and lower spindles will be deformed, affecting the service life and reaming effect of the rotary eccentric reaming tool; the second is the circumferential reaction force, that is, the circumferential force generated by cutting, which makes the eccentric drill bit react to the surrounding environment during the revolution. These two reaction forces jointly affect the cutting effect of the eccentric drill bit and the working performance of the entire reamer. Moreover, the main function of the eccentric drill bit is drilling, and eye expansion is a supplementary function. Due to the size limitation, the rock wall after eye expansion is relatively rough, resulting in poor eye expansion quality.

[0045] Based on the above problems, the utility model provides an eccentric reamer for oil drilling, such as Figure 2As shown, the eccentric reamer includes an upper connector 100 (also as shown in Figure 5 As shown), the reamer barrel 400, the screw 200 (also as Figure 7 As shown), the lower connector 300 (also as Figure 6 As shown) and the reamer 500 (as shown Figure 4 The upper joint 100 is provided with a first flow channel 110 in the middle, which is connected to the spiral cavity below through at least one first flow hole 120 to achieve smooth circulation of mud or other fluids; the reaming barrel 400 is connected to the upper joint 100 and has a spiral cavity eccentrically arranged in the middle (from Figure 2 It can be clearly seen that there are two center lines, the upper center line is the center line of the screw 200 and the reaming barrel 400, and the lower center line is the center line of the upper joint 100 and the lower joint 300), which is intended to achieve compound rotational motion through the flow of mud and the rotation of the screw 200; the screw 200 is connected to the upper joint 100, arranged in the spiral cavity, and rotates under the drive of the mud and drives the reaming barrel 400 to rotate; the lower joint 300 is connected to the bottom of the reaming barrel 400, connected to the screw 200, and is provided with a second flow hole 320 and a second flow channel 310 to ensure effective discharge of the fluid; the reaming piece 500 is located at the outer edge of the reaming barrel 400, and is used to cut the well wall for reaming operation. The above components work together, so that the eccentric reamer can efficiently change the wellbore size, adapt to different formation conditions, and improve drilling efficiency.

[0046] The uniqueness of the eccentric reamer for oil drilling provided by the utility model lies in that the reamer 500 is cleverly arranged on the outer edge of the reamer barrel 400 and is on the same horizontal line with the rotary drive source (i.e., the screw 200). The advantages of this layout are obvious: first, when the reamer 500 is subjected to a reaction force when cutting the rock wall, the support of the reamer barrel 400 and the screw 200 effectively reduces the risk of damage to the reamer 500 due to excessive torque, thereby improving the durability and reliability of the reamer. Secondly, since the reamer 500 and the screw 200 are on the same horizontal line, the problem that the screw 200 may be bent or broken due to the lever effect is eliminated, making the system more stable and reliable. At the same time, by setting the first flow channel 110, the first flow hole 120, the spiral cavity, the second flow hole 320 and the second flow channel 310, the smooth flow of mud as the driving fluid is ensured, further improving the working efficiency of the entire system.

[0047] In a further preferred embodiment of the present invention, Figure 3As shown, an upper wear-resistant sleeve is used at the connection between the upper joint 100 and the reaming barrel 400, or an upper wear-resistant sleeve is connected to the upper part of the reaming barrel 400, and the provision of the upper wear-resistant sleeve forms a first gap between the upper joint 100 and the reaming barrel 400. The presence of the upper wear-resistant sleeve effectively reduces the surface area of ​​direct contact between the upper joint 100 and the reaming barrel 400, reduces the degree of wear caused by friction, and thus extends the service life of these two key components. In addition, the introduction of the upper wear-resistant sleeve makes the relative movement between the upper joint 100 and the reaming barrel 400 smoother, reduces the irregular friction of the contact surface, improves the stability of the entire system, and ensures the reliability of the eccentric reamer under various working conditions. Furthermore, by forming the first gap, external substances (such as mud or cutting debris) are effectively prevented from entering the connection between the upper joint 100 and the reaming barrel 400, thereby avoiding equipment damage or performance degradation caused by the intrusion of foreign matter. The above structural design comprehensively considers the requirements of wear resistance, stability and barrier properties, and improves the overall performance and reliability of the eccentric reamer.

[0048] In the specific implementation, the first upper wear-resistant sleeve 510 is used at the connection between the upper joint 100 and the reaming barrel 400, and the upper part of the reaming barrel 400 is connected with the second upper wear-resistant sleeve 520, and the two upper wear-resistant sleeves are fitted together by staggering to form a double-layer wear-resistant protection structure, that is, the setting of the first upper wear-resistant sleeve 510 and the second upper wear-resistant sleeve 520 prevents the upper joint 100 and the reaming barrel 400 from rubbing against each other, and thus will not wear each other. The setting of the double upper wear-resistant sleeves effectively improves the wear resistance and durability of the connection between the upper joint 100 and the reaming barrel 400, reduces the friction loss caused by the reaming operation, and further extends the service life of the entire system. Furthermore, the staggered fitting between the first upper wear-resistant sleeve 510 and the second upper wear-resistant sleeve 520 creates a tighter combination, prevents mud or other external substances from entering the connection area between the upper joint 100 and the reaming barrel 400, improves the sealing of the connection part, and helps maintain the stable operation of the system. In addition, through the staggered fitting of the first upper wear-resistant sleeve 510 and the second upper wear-resistant sleeve 520, a more compact and optimized structural layout is achieved, which is not only conducive to the lightweight design of the overall equipment, but also improves the reliability and flexibility of the system.

[0049] Specifically, Figure 3 As shown, the first upper wear-resistant sleeve 510 is inlaid with a first wear-resistant block 511 on the side facing the second upper wear-resistant sleeve 520, while the second upper wear-resistant sleeve 520 is inlaid with a second wear-resistant block 521 on the side facing the first upper wear-resistant sleeve 510. When the reaming barrel 400 rotates, the first wear-resistant block and the second wear-resistant block rub against each other, and a gap is reserved between the main body of the first wear-resistant sleeve and the main body of the second wear-resistant sleeve to reduce the use of wear-resistant materials.

[0050] Similarly, the utility model is also provided with a lower wear-resistant sleeve. Preferably, the lower wear-resistant sleeve adopts the same structural configuration as the upper wear-resistant sleeve. Since the lower wear-resistant sleeve adopts the same structural configuration as the upper wear-resistant sleeve, the lower wear-resistant sleeve has the same technical effect as the upper wear-resistant sleeve, which will not be repeated here.

[0051] According to another aspect of the present invention, the outer edge of the reamer barrel 400 is provided with a plurality of protrusions 410, such as Figure 4 As shown, each protrusion 410 is provided with a plurality of mounting holes, and this structure provides a flexible and diverse configuration for the reamer. The operator can select reamer pieces 500 of different types and specifications according to actual needs, and install them one by one in the mounting holes on the protrusion 410, so that the performance configuration of the reamer is more flexible and can be customized according to the geological conditions of the wellbore or the operation requirements.

[0052] The reamer 500 can be relatively freely placed in the mounting hole on the protrusion 410 as needed, which means that the operator can flexibly adjust the cutting position of the reamer 500 according to the actual situation to adapt to the special requirements of different wellbore sections, thereby improving the applicability and cutting accuracy of the reamer. In addition, through the setting of the mounting holes, the replacement and maintenance of the reamer 500 become relatively independent, simplifying the operating steps of daily maintenance, reducing system downtime, and improving the maintainability of the reamer. By selecting the appropriate mounting hole configuration, efficient cutting of different wellbore formations can be achieved, the cutting efficiency of the reamer can be maximized, providing a more efficient and economical solution for oil production and drilling operations, and enhancing the flexibility and operability of the entire system.

[0053] Furthermore, the protrusion 410 is provided with a first inclined surface 411 at one end facing the lower joint 300, and a plurality of reamer pieces 500 are installed on the first inclined surface 411. Since the lower joint 300 is closest to the drill bit, and the first inclined surface 411 is the first part to contact the wellbore wall, by setting this part as an inclined surface, a gradual process of gradually increasing the diameter of the eccentric reamer is achieved. The above-mentioned setting effectively reduces the resistance during cutting and reduces the friction between the reamer and the wellbore wall, thereby improving the cutting quality and cutting speed, and reducing the energy consumption during cutting. A plurality of reamer pieces 500 are arranged on the first inclined surface 411, which can meet the cutting requirements at different angles. By distributing a plurality of reamer pieces 500 on the first inclined surface 411, the eccentric reamer can better adapt to different geological conditions or special requirements of wellbore sections, which not only improves the flexibility of work, but also enables the eccentric reamer to adapt to various working conditions more accurately, thereby improving the applicability and efficiency of the overall system.

[0054] Preferably, the protrusion 410 is provided with a second inclined surface 412 at one end facing the upper joint 100, and a plurality of reamer pieces 500 are installed on the inclined surface. When back-reaming is required, the second inclined surface 412 will be the first part to contact the rock wall. By setting this part as an inclined surface, a gradual process of gradually increasing the back-reaming diameter of the eccentric reamer is achieved. This setting effectively reduces the resistance during cutting and reduces the friction between the reamer and the well wall, thereby improving the cutting quality and cutting speed. A plurality of reamer pieces 500 are provided on the second inclined surface 412 to meet the cutting requirements at different angles. By distributing a plurality of reamer pieces 500 on the second inclined surface 412, the eccentric reamer can better adapt to different geological conditions or special requirements of wellbore sections, which not only improves the flexibility of the work, but also enables the eccentric reamer to adapt to various working conditions more accurately, thereby improving the applicability and efficiency of the overall system.

[0055] In a specific implementation, the protrusions 410 are arranged at intervals along the outer edge of the reaming barrel 400, and the side wall of the protrusion 410 is a vertical surface, on which a plurality of reaming pieces 500 are arranged. The reaming pieces 500 are arranged on the side wall of the protrusion 410, so that the reaming piece 500, rather than the corner of the side wall, will first contact the rock wall, providing protection for the protrusion 410; the plurality of reaming pieces 500 are arranged on the vertical surface of the protrusion 410, on the one hand, so that multi-point cutting can be performed simultaneously during the reaming process, reducing the load of each reaming piece 500, reducing the resistance of single-point cutting, and improving the cutting effect; on the other hand, the uniform arrangement of the plurality of protrusions 410 enables the reaming barrel 400 to uniformly cut the well wall when rotating, improving the cutting efficiency and uniformity; and the vertical surface of the protrusion 410 provides additional support, reducing the vibration and swing of the reaming piece 500 during the cutting process, enhancing the stability of the entire eccentric reamer, and reducing the risk of damage that may be caused by unstable cutting.

[0056] According to another aspect of the utility model, a smooth rod is provided on the side of the screw 200 facing the lower joint 300, and a third gap is formed between the smooth rod and the inner wall of the reaming barrel 400. The existence of the third gap is conducive to the smooth flow of mud, ensuring that the mud can easily flow between the screw 200 and the reaming barrel 400, thereby ensuring the transmission of driving force and the normal operation of the eccentric reamer, which not only ensures the smooth circulation of mud during the operation of the reamer, but also helps to maintain the efficiency of the drive system. In addition, the design of the third gap also has the effect of reducing the direct contact between the screw 200 and the inner wall of the reaming barrel 400, effectively reducing the wear caused by friction during high-speed rotation, extending the service life of the screw 200 and the reaming barrel 400, and improving the durability of the entire system. The design of the smooth rod makes the movement between the screw 200 and the reaming barrel 400 smoother, reduces the vibration and noise levels, and thus improves the overall operation stability of the eccentric reamer.

[0057] Preferably, the lower joint 300 is provided with a frustoconical docking portion at one end facing the screw 200, and the screw 200 is provided with a receiving groove adapted to the docking portion. The frustoconical docking portion can provide a larger guiding surface, so that the lower joint 300 and the screw 200 can be more easily aligned in position when docking, ensuring the normal coordination of various components of the reamer during operation; in addition, the design of the frustoconical docking portion and the receiving groove makes the installation between the lower joint 300 and the screw 200 easier. When docking, it is only necessary to guide the docking portion into the receiving groove to achieve fast and accurate assembly, thereby improving the installation efficiency; at the same time, the combination of the frustoconical docking portion and the receiving groove provides a larger contact area, ensuring a firm connection between the lower joint 300 and the screw 200, preventing looseness or swinging during operation, and improving the stability of the system; moreover, the frustoconical docking portion can effectively transmit the load received during the reaming process, ensuring uniform distribution of force, and reducing unnecessary stress concentration on the connecting components.

[0058] It should be noted that the above embodiments illustrate the utility model rather than limit the utility model, and those skilled in the art may design alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be constructed as a limitation on the claims. The word "comprising" does not exclude the existence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the existence of multiple such elements. The utility model can be implemented by means of hardware including several different elements and by means of appropriately programmed computers. In a unit claim that lists several devices, several of these devices may be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names. The steps in the above embodiments should not be understood as limitations on the order of execution unless otherwise specified.

Claims

1. An eccentric reamer for oil drilling, characterized in that: include: An upper joint, wherein a first flow channel is opened in the middle of the upper joint, and the first flow channel is connected with at least one first flow hole; An reaming cylinder, the reaming cylinder is connected to the upper joint, a spiral cavity connected to the first flow hole is opened in the middle, and the spiral cavity is eccentrically arranged relative to the first flow channel; A screw rod, the screw rod is connected to the upper joint, is disposed in the spiral cavity, and is used to rotate under the drive of the fluid flowing out of the first flow hole and drive the reaming cylinder to rotate; A lower joint, the lower joint is connected to the end of the reaming barrel away from the upper joint, is connected to the screw, and is provided with a second flow hole and a second flow channel for discharging fluid; The reamer is arranged on the outer edge of the reamer barrel and is used for cutting the well wall to expand the hole.

2. The eccentric reamer for oil drilling according to claim 1, characterized in that: An upper wear-resistant sleeve is connected to one end of the upper joint facing the reaming cylinder, and / or an upper wear-resistant sleeve is connected to one end of the reaming cylinder facing the upper joint, and the upper wear-resistant sleeve forms a first gap between the upper joint and the reaming cylinder.

3. The eccentric reamer for oil drilling according to claim 2, characterized in that: The end of the upper joint facing the reaming cylinder is connected with a first upper wear-resistant sleeve, and the end of the reaming cylinder facing the upper joint is connected with a second upper wear-resistant sleeve, and the first upper wear-resistant sleeve and the second upper wear-resistant sleeve are staggered and fitted together.

4. The eccentric reamer for oil drilling according to claim 1, characterized in that: The end of the lower joint facing the reaming cylinder is connected to a lower wear-resistant sleeve, and / or the end of the reaming cylinder facing the lower joint is connected to a lower wear-resistant sleeve, and the lower wear-resistant sleeve forms a second gap between the lower joint and the reaming cylinder.

5. The eccentric reamer for oil drilling according to claim 1, characterized in that: The outer edge of the reaming cylinder is provided with a plurality of protrusions, the protrusions are provided with a plurality of mounting holes, and the reaming members are accommodated in the mounting holes one by one.

6. The eccentric reamer for oil drilling according to claim 5, characterized in that: The protrusion is provided with a first inclined surface at one end facing the lower joint, and a plurality of eye-expanding members are provided on the first inclined surface.

7. The eccentric reamer for oil drilling according to claim 5, characterized in that: The protrusion is provided with a second inclined surface at one end facing the upper joint, and a plurality of eye-expanding pieces are provided on the second inclined surface.

8. The eccentric reamer for oil drilling according to claim 5, characterized in that: A plurality of protrusions are arranged at intervals along the outer edge of the reaming cylinder, and a side wall of the protrusion is a vertical surface, on which a plurality of reaming pieces are arranged.

9. The eccentric reamer for oil drilling according to claim 1, characterized in that: A smooth rod portion is disposed on the side of the screw rod facing the lower joint, and a third gap is formed between the smooth rod portion and the inner wall of the reaming barrel.

10. The eccentric reamer for oil drilling according to claim 1, characterized in that: The lower joint is provided with a frustoconical docking portion at one end facing the screw rod, and the screw rod is provided with a receiving groove matched with the docking portion.

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