High-torque screw drilling tool for petroleum drilling and use method of high-torque screw drilling tool

Abstract

The invention relates to an underground power drilling tool for petroleum drilling, in particular to a high-torque screw drilling tool for petroleum drilling and a using method. According to the technical scheme, the outer wall of a fixing screw rod serving as a stator is sleeved with a rotary pump cylinder serving as a rotor, a rubber bushing is fixed to the inner wall of the rotary pump cylinder in a vulcanized mode, and spiral curved surfaces are evenly distributed in the rubber bushing and used for being meshed with spiral line grooves in the outer wall of the fixing screw rod to form a spiral sealing cavity; a rotary centralizer is installed outside the rotary pump cylinder, a pump cylinder lower connector used for being connected with a drill bit is arranged at the lower end of the rotary pump cylinder, and the drill bit is driven to rotate through rotation of the rotary pump cylinder to achieve the drilling action. The screw drilling tool has the beneficial effects that the rotary pump cylinder serves as a rotor of screw drilling, the fixed screw serves as a stator of screw drilling, and the drill bit is connected to the lower end of the rotary pump cylinder, so that the torque of the screw drilling tool is improved to the maximum extent under the condition of limited borehole size, and the drill bit meets more scene requirements.

Description

Technical Field

[0001] This invention relates to a downhole power drilling tool for oil drilling, and more particularly to a high-torque screw drilling tool for oil drilling and its usage method. Background Technology

[0002] Liquid-driven downhole power drills, also known as downhole motors or power units, are drill tools specifically designed for downhole power drilling. Their core function is to convert the liquid energy at the surface into mechanical energy downhole, thereby driving the drill bit to generate torque to break rocks. This drilling method is called downhole power drilling. Its working principle is as follows: After high-pressure drilling fluid enters the screw drill, it is compressed through the helical channel between the stator (pump barrel) and the rotor (screw). This process creates alternating high-pressure and low-pressure chambers between the stator and rotor. Due to the pressure difference, the rotor experiences eccentric displacement, the so-called eccentric torque. As the drilling fluid continues to flow downwards, new high-pressure and low-pressure chambers are continuously generated. These chambers, under the influence of the pressure difference, continuously push the rotor to move. This cycle repeats, and the rotor rotates continuously within the screw drill, generating mechanical energy. In short, when the drilling fluid flows through the motor, the pressure difference between the inlet and outlet drives the rotor's rotation, which in turn transmits torque and speed to the drill bit through the universal joint and drive shaft, realizing the conversion of liquid pressure energy into mechanical energy.

[0003] However, the existing technology has a problem: the rotor (screw) is located inside the stator (pump barrel), which means the outer diameter of the screw's cross-section is smaller than the inner diameter of the pump barrel's cross-section. Since the drill bit connected below inevitably encounters rock layers during drilling, it is desirable to have a higher drill bit torque. The drill bit torque comes from the torque transmitted from the screw. Existing screws are already made of high-strength steel, so theoretically, the torque can only be increased by machining a thicker screw. This results in a larger screw drill bit size, which in turn limits the upper limit of the screw drill bit size due to the wellbore size. Therefore, how to further improve the rotor (screw) torque is an urgent problem to be solved.

[0004] Additionally, it's important to note the following relationship between shaft diameter and transmitted torque: the shaft's diameter has a crucial impact on the torque it can transmit. From a mechanical perspective, torque is the force that causes a shaft to rotate, and the shaft needs sufficient strength and stiffness to withstand and transmit this torque. Shafts with larger diameters generally have stronger torsional resistance and can transmit greater torque. This is because the shaft's torsional section modulus is proportional to the cube of its diameter. Simply put, the torsional section modulus is like an indicator of a shaft's resistance to torsional failure; the higher its value, the less likely the shaft is to deform or break under torsional stress. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned deficiencies in the existing technology by providing a high-torque screw drill bit for oil drilling and its usage method. By using a rotary pump barrel as the rotor of the screw drill and a fixed screw as the stator, and connecting the drill bit to the lower end of the rotary pump barrel, the torque of the screw drill bit is maximized within a limited wellbore size, enabling the drill bit to meet the needs of more scenarios.

[0006] This invention relates to a high-torque screw drill bit for oil drilling, the technical solution of which includes an upper screw connector, a fixed screw, a rotary stabilizer, a bearing assembly, a rubber bushing, a rotary pump barrel, a stabilizer retaining ring, a lower screw connector, and a lower pump barrel connector. The upper screw connector, serving as the stator, is installed at the upper end of the fixed screw for connection to coiled tubing. A rotary pump barrel, acting as the rotor, is fitted onto the outer wall of the fixed screw. The inner wall of the rotary pump barrel is vulcanized with a fixed rubber bushing. The rubber bushing contains uniformly distributed helical curved surfaces for engagement with the helical grooves on the outer wall of the fixed screw. A spiral sealing cavity is formed; rotary stabilizers are installed on the upper and lower sides of the outer wall of the rotary pump barrel, and the two sides of the rotary stabilizers are limited by the installation of stabilizer retaining rings. The inner wall of the rotary stabilizer is movably connected to the outer wall of the end of the rotary pump barrel. The inner wall of the upper end of the rotary pump barrel is movably connected to the upper screw connector through a bearing assembly, and the inner wall of the lower end of the rotary pump barrel is movably connected to the lower screw connector through a bearing assembly. The lower end of the rotary pump barrel is provided with a pump barrel lower connector for connecting to the drill bit. The drilling action is achieved by rotating the rotary pump barrel to drive the drill bit to rotate.

[0007] Preferably, an upper sealing cap is installed on the upper side of the bearing assembly at the upper end of the rotary pump cylinder, and a sealing retaining ring is installed on the lower side of the bearing assembly; a lower fixing cap is installed on the lower side of the bearing assembly at the lower end of the rotary pump cylinder, and a sealing retaining ring is installed on the upper side of the bearing assembly.

[0008] Preferably, the rotary centralizer includes an inner cylinder, a rotary bearing, an outer centralizing body, a liquid passage groove, and an outer centralizing block. The inner wall of the inner cylinder is connected and fixed to the outer wall of the rotary pump cylinder. The outer wall of the inner cylinder is movably connected to the outer centralizing body through multiple sets of rotary bearings, and a rotary seal is installed at the outer end of the rotary bearing. Multiple sets of outer centralizing blocks and multiple sets of liquid passage grooves are evenly distributed on the outer wall of the outer centralizing body, and the outer centralizing blocks and liquid passage grooves are arranged at intervals.

[0009] Preferably, the inner wall center of the outer straightening body is provided with an inner protrusion ring, and multiple sets of rotary bearings are installed on the upper and lower sides of the inner protrusion ring, and the multiple sets of rotary bearings slide in contact with the outer wall of the inner cylinder; the outer sides of both ends of the outer straightening body are respectively provided with chamfers.

[0010] Preferably, the rotary pump barrel includes a pump barrel body, an upper bearing assembly mounting part, an upper pressure cap thread, a retaining ring thread, a lower bearing assembly mounting part, and a lower pressure cap thread. A rubber bushing is injected into the inner wall of the middle part of the pump barrel body. The upper end of the pump barrel body is provided with an upper bearing assembly mounting part and an upper pressure cap thread, and the lower end of the pump barrel body is provided with a lower bearing assembly mounting part and a lower pressure cap thread. Two sets of retaining ring threads are provided on both sides of the outer wall of the pump barrel body for installing the centralizer retaining ring.

[0011] Preferably, the upper end of the fixed screw is provided with a high-pressure liquid flow channel. The high-pressure liquid enters the upper joint of the screw along the continuous oil pipe, and then enters the spiral sealing cavity formed by the spiral curved surface inside the rubber bushing and the spiral groove on the outer wall of the fixed screw through the high-pressure liquid flow channel, thereby driving the rotary pump barrel to rotate.

[0012] Preferably, auxiliary vanes are installed on the outer wall of the rotary pump cylinder, and the auxiliary vanes are spiral structures that are evenly distributed on the outer wall of the rotary pump cylinder.

[0013] Preferably, the direction of rotation of the auxiliary blade is opposite to the direction of rotation of the helical groove of the fixed screw.

[0014] The method of using the high-torque screw drill bit for oil drilling mentioned in this invention includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing is vulcanized and fixed to the inner wall of the rotary pump barrel, and the inner wall of the rubber bushing is uniformly provided with a spiral curved surface. Then, rotary stabilizers are installed on both sides of the outer wall of the rotary pump barrel and fixed and limited by the stabilizer retaining rings. Then, the fixing screw is installed in the inner cavity of the rotary pump barrel, the upper end of the fixing screw is connected to the upper screw connector, and the lower end of the fixing screw is connected to the lower screw connector. Then, the bearing assembly and the upper sealing cap are installed in the annular space between the inner wall of the rotary pump barrel and the upper screw connector, and the bearing assembly and the lower fixing cap are installed in the annular space between the inner wall of the rotary pump barrel and the lower screw connector. II. Application of high-torque screw drill bits for oil drilling: A screw joint is connected to the lower end of the coiled tubing. The high-torque screw drill bit for oil drilling is sent into the well through the coiled tubing. The rotary centralizer acts as a centralizer for the rotary pump barrel. Then, high-pressure power fluid is injected into the coiled tubing at the wellhead. The high-pressure power fluid enters the screw joint through the coiled tubing, and then enters the spiral sealing cavity formed by the helical curved surface of the rubber bushing and the helical groove of the fixed screw through the high-pressure fluid flow channel. The fixed screw acts as the stator and the rotary pump barrel acts as the rotor, completing the conversion of liquid pressure energy into mechanical energy, realizing the rotation of the rotary pump barrel, and then driving the drill bit connected to the lower end of the rotary pump barrel to rotate, realizing the drilling action of the drill bit. In addition, since multiple sets of external centralizing blocks and fluid passages are evenly distributed on the outer wall of the external centralizing body of the rotary centralizer, after the high-pressure power fluid drives the rotary pump barrel to rotate, it continues to spray downward through the end of the drill bit. The sand and gravel generated by the drill bit mixing with the high-pressure power fluid to form mud, then moving upward along the fluid passage of the rotary centralizer in the opposite direction, and finally, the mud is discharged upward to the surface along the annulus between the coiled tubing and the wellbore.

[0015] The method of using the high-torque screw drill bit for oil drilling mentioned in this invention includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing is vulcanized and fixed to the inner wall of the rotary pump barrel, and the inner wall of the rubber bushing is uniformly provided with a spiral curved surface. Then, rotary stabilizers are installed on both sides of the outer wall of the rotary pump barrel and fixed and limited by the stabilizer retaining rings. Then, the fixing screw is installed in the inner cavity of the rotary pump barrel, the upper end of the fixing screw is connected to the upper screw connector, and the lower end of the fixing screw is connected to the lower screw connector. Then, the bearing assembly and the upper sealing cap are installed in the annular space between the inner wall of the rotary pump barrel and the upper screw connector, and the bearing assembly and the lower fixing cap are installed in the annular space between the inner wall of the rotary pump barrel and the lower screw connector. II. Application of High-Torque Screw Drill Strings for Oil Drilling A screw joint is connected to the lower end of the coiled tubing. The high-torque screw drill string for oil drilling is then sent into the well through the coiled tubing. The rotary centralizer acts as a centralizer for the rotary pump barrel. Then, high-pressure power fluid is injected into the coiled tubing at the wellhead. The high-pressure power fluid enters the screw joint through the coiled tubing, and then enters the spiral sealing cavity formed by the helical curved surface of the rubber bushing and the helical groove of the fixed screw through the high-pressure fluid flow channel. The fixed screw acts as the stator, and the rotary pump barrel acts as the rotor, completing the conversion of liquid pressure energy into mechanical energy, realizing the rotation of the rotary pump barrel, which in turn drives the drill bit connected to the lower end of the rotary pump barrel to rotate, realizing the drilling action of the drill bit. Since the diameter of the rotary pump barrel is larger than the diameter of the fixed screw, the torque of the screw drill string is greatly increased. In addition, because multiple sets of external centralizing blocks and fluid passages are evenly distributed on the outer wall of the outer centralizing body of the rotary centralizer, after the high-pressure power fluid drives the rotary pump barrel to rotate, it continues to spray downwards through the end of the drill bit. The sand and gravel generated during drilling mix with the high-pressure power fluid to form mud, which then moves upwards along the fluid passage of the rotary centralizer. Because a spiral-shaped auxiliary vane is installed on the outer wall of the rotary pump barrel, the upward-moving mud helps to drive the rotation of the rotary pump barrel, further improving the torque transmission of the rotary pump barrel. Finally, the mud is discharged upwards to the surface along the annulus between the coiled tubing and the wellbore.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: I. This invention uses a rotary pump barrel as the rotor of a screw drilling machine and a fixed screw as the stator. By interchangeing the rotor and stator, the diameter of the rotary pump barrel is larger than the outer diameter of the fixed screw, thereby increasing the torque-transmitting diameter of the rotary pump barrel. Therefore, it improves the torque of the screw drilling tool under limited wellbore size, and thus drives the drill bit to meet the needs of more scenarios. Second, by using a rotary pump barrel as the rotor of screw drilling and a fixed screw as the stator of screw drilling, this invention achieves the interchangeability of the rotor and stator, making it possible to add auxiliary vanes to the outer wall of the rotary pump barrel. Therefore, after adding auxiliary vanes, not only is the torsional resistance of the rotary pump barrel increased, but the torque transmission of the rotary pump barrel is also improved, and the energy utilization efficiency is also improved. Third, by installing rotary stabilizers on both sides of the outer wall of the rotary pump barrel, this invention not only ensures the normal rotation of the rotary pump barrel, but also avoids damage to the inner wall of the wellbore caused by the rotary pump barrel, and also avoids damage to the inner wall of the wellbore caused by the use of fixed stabilizers. Fourth, due to the increased torque of the screw drill bit, combined with the use of coiled tubing, drilling operations can be easily realized, thereby shortening the drilling time and saving a lot of costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention; Figure 2 This is a partial cross-sectional schematic diagram of a rotary centralizer; Figure 3 This is a top view of the structure of a rotary centralizer; Figure 4 This is a schematic diagram of the structure of a rotary pump cylinder; Figure 5 This is a schematic diagram of the structure of an auxiliary vane installed on the outside of a rotary pump barrel; Figure 6 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention; Figure 7 This is a schematic diagram of the construction process of the present invention; In the diagram: 1. Upper screw connector, 2. Fixed screw, 3. Rotary centralizer, 4. Upper sealing cap, 5. Bearing assembly, 6. Rubber bushing, 7. Rotary pump barrel, 8. Centralizer retaining ring, 9. Lower fixed cap, 10. Auxiliary vane, 11. Sealing retaining ring, 12. Lower screw connector, 13. Lower pump barrel connector, 14. Coiled tubing, 15. Drill bit, 16. Wellbore, 2.1. High-pressure fluid flow channel, 3.1. Inner cylinder, 3.1. Rotary bearing, 3.2. Rotary seal, 3.3. Outer centralizer body, 3.4. Fluid passage, 3.5. Outer centralizer block, 3.6. Inner raised ring, 3.4.1. Chamfer, 3.4.2. Helical surface, 6.1. Pump barrel body, 7.1. Upper bearing assembly mounting part, 7.2. Upper cap thread, 7.3. Retaining ring thread, 7.4. Lower bearing assembly mounting part, 7.5. Lower cap thread, 7.6. Detailed Implementation

[0018] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0019] Example 1, referring to Figures 1-4 , Figure 7 The present invention discloses a high-torque screw drill bit for oil drilling, the technical solution of which includes an upper screw connector 1, a fixed screw 2, a rotary stabilizer 3, a bearing assembly 5, a rubber bushing 6, a rotary pump barrel 7, a stabilizer retaining ring 8, a lower screw connector 12, and a lower pump barrel connector 13. The upper screw connector 1 is installed on the upper end of the fixed screw 2, which serves as the stator, for connection to the coiled tubing 14. The rotary pump barrel 7, which serves as the rotor, is sleeved on the outer wall of the fixed screw 2, and the inner wall of the rotary pump barrel 7 is vulcanized with a fixed rubber bushing 6. The rubber bushing 6 has a uniformly distributed helical curved surface 6.1 for meshing with the helical grooves on the outer wall of the fixed screw 2. A spiral sealing cavity is formed; rotary stabilizers 3 are respectively installed on the upper and lower sides of the outer wall of the rotary pump barrel 7, and the two sides of the rotary stabilizers 3 are limited by the installation of stabilizer retaining rings 8. The inner wall of the rotary stabilizer 3 is movably connected to the outer wall of the end of the rotary pump barrel 7. The inner wall of the upper end of the rotary pump barrel 7 is movably connected to the upper screw connector 1 through the bearing assembly 5. The inner wall of the lower end of the rotary pump barrel 7 is movably connected to the lower screw connector 12 through the bearing assembly 5. The lower end of the rotary pump barrel 7 is provided with a pump barrel lower connector 13 for connecting with the drill bit 15. The drilling action is achieved by rotating the rotary pump barrel 7 to drive the drill bit 15 to rotate.

[0020] In this design, an upper sealing cap 4 is installed on the upper side of the bearing assembly 5 at the upper end of the rotary pump cylinder 7, and a sealing retaining ring 11 is installed on the lower side of the bearing assembly 5; a lower fixing cap 9 is installed on the lower side of the bearing assembly 5 at the lower end of the rotary pump cylinder 7, and a sealing retaining ring 11 is installed on the upper side of the bearing assembly 5.

[0021] Reference Figure 2 and Figure 3 The rotary centralizer 3 mentioned in this invention includes an inner cylinder 3.1, a rotary bearing 3.2, an outer centralizer body 3.4, a liquid passage trough 3.5, and an outer centralizer block 3.6. The inner wall of the inner cylinder 3.1 is connected and fixed to the outer wall of the rotary pump cylinder 7. The outer wall of the inner cylinder 3.1 is movably connected to the outer centralizer body 3.4 through multiple sets of rotary bearings 3.2. A rotary seal 3.3 is installed at the outer end of the rotary bearing 3.2. Multiple sets of outer centralizer blocks 3.6 and multiple sets of liquid passage troughs 3.5 are evenly distributed on the outer wall of the outer centralizer body 3.4, and the outer centralizer blocks 3.6 and liquid passage troughs 3.5 are arranged at intervals.

[0022] The outer straightening body 3.4 has an inner protruding ring 3.4.1 at the center of its inner wall. Multiple sets of rotary bearings 3.2 are installed on the upper and lower sides of the inner protruding ring 3.4.1, and the multiple sets of rotary bearings 3.2 slide in contact with the outer wall of the inner cylinder 3.1. The outer sides of both ends of the outer straightening body 3.4 are respectively provided with chamfers 3.4.2 to reduce the damage to the well wall when the outer straightening body 3.4 moves in the well.

[0023] Reference Figure 4 The rotary pump barrel 7 mentioned in this invention includes a pump barrel body 7.1, an upper bearing assembly mounting part 7.2, an upper pressure cap thread 7.3, a retaining ring thread 7.4, a lower bearing assembly mounting part 7.5, and a lower pressure cap thread 7.6. A rubber bushing 6 is injected into the inner wall of the middle part of the pump barrel body 7.1. The upper end of the pump barrel body 7.1 is provided with the upper bearing assembly mounting part 7.2 and the upper pressure cap thread 7.3, and the lower end of the pump barrel body 7.1 is provided with the lower bearing assembly mounting part 7.5 and the lower pressure cap thread 7.6. Two sets of retaining ring threads 7.4 are respectively provided on both sides of the outer wall of the pump barrel body 7.1 for installing the centralizer retaining ring 8.

[0024] The upper end of the fixed screw 2 is provided with a high-pressure liquid flow channel 2.1. The high-pressure liquid enters the upper joint 1 of the screw along the continuous oil pipe 14, and then enters the spiral sealing cavity formed by the spiral curved surface 6.1 inside the rubber bushing 6 and the spiral groove on the outer wall of the fixed screw 2 through the high-pressure liquid flow channel 2.1, thereby driving the rotary pump barrel 7 to rotate.

[0025] The method of using the high-torque screw drill bit for oil drilling mentioned in this invention includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing 6 is vulcanized and fixed to the inner wall of the rotary pump barrel 7, and the inner wall of the rubber bushing 6 is uniformly provided with a spiral curved surface 6.1. Then, rotary stabilizers 3 are installed on both sides of the outer wall of the rotary pump barrel 7, and fixed and limited by stabilizer retaining rings 8. Then, the fixing screw 2 is installed in the inner cavity of the rotary pump barrel 7, the upper end of the fixing screw 2 is connected to the upper screw connector 1, and the lower end of the fixing screw 2 is connected to the lower screw connector 12. Then, the bearing assembly 5 and the upper sealing cap 4 are installed in the annular space between the inner wall of the rotary pump barrel 7 and the upper screw connector 1, and the bearing assembly 5 and the lower fixing cap 9 are installed in the annular space between the inner wall of the rotary pump barrel 7 and the lower screw connector 12. II. Application of High-Torque Screw Drill Strings for Oil Drilling Reference Figure 7 A screw connector 1 is connected to the lower end of the coiled tubing 14. The high-torque screw drill bit for oil drilling is sent into the well through the coiled tubing 14. The rotary centralizer 3 acts as a centralizer for the rotary pump barrel 7. Then, high-pressure power fluid is injected into the coiled tubing 14 at the wellhead. The high-pressure power fluid enters the screw connector 1 through the coiled tubing 14, and then enters the spiral sealing cavity formed by the spiral curved surface 6.1 of the rubber bushing 6 and the spiral groove of the fixed screw 2 through the high-pressure fluid flow channel 2.1. The fixed screw 2 acts as the stator and the rotary pump barrel 7 acts as the rotor, completing the conversion of liquid pressure energy into mechanical energy, realizing the rotation of the rotary pump barrel 7, and then driving the drill bit 15 connected to the lower end of the rotary pump barrel 7 to rotate, realizing the drilling action of the drill bit 15. In addition, since multiple sets of external centralizing blocks 3.6 and fluid passages 3.5 are evenly distributed on the outer wall of the outer centralizing body 3.4 of the rotary centralizer 3, after the high-pressure power fluid drives the rotary pump barrel 7 to rotate, it continues to spray downward through the end of the drill bit 15. The sand and gravel generated by the drill bit 15 during drilling mix with the high-pressure power fluid to form mud, and then moves upward along the fluid passages 3.5 of the rotary centralizer 3 in the opposite direction. Finally, the mud is discharged upward to the surface along the annulus between the coiled tubing 14 and the wellbore 16.

[0026] Example 2: The technical solution of the high-torque screw drill bit for oil drilling mentioned in this invention is as follows: It includes an upper screw connector 1, which further includes a fixed screw 2, a rotary stabilizer 3, a bearing assembly 5, a rubber bushing 6, a rotary pump barrel 7, a stabilizer retaining ring 8, a lower screw connector 12, and a lower pump barrel connector 13. The upper screw connector 1 is installed on the upper end of the fixed screw 2, which serves as the stator, for connection with the coiled tubing 14. The rotary pump barrel 7, which serves as the rotor, is sleeved on the outer wall of the fixed screw 2, and the inner wall of the rotary pump barrel 7 is vulcanized with a fixed rubber bushing 6. The rubber bushing 6 has a uniformly distributed helical curved surface 6.1 for contacting the helical grooves on the outer wall of the fixed screw 2. The rotating pump barrel 7 is meshed to form a spiral sealing cavity. Rotary stabilizers 3 are installed on the upper and lower sides of the outer wall of the rotating pump barrel 7, and the two sides of the rotating stabilizers 3 are limited by the installation of stabilizer retaining rings 8. The inner wall of the rotating stabilizer 3 is movably connected to the outer wall of the end of the rotating pump barrel 7. The inner wall of the upper end of the rotating pump barrel 7 is movably connected to the upper screw connector 1 through the bearing assembly 5. The inner wall of the lower end of the rotating pump barrel 7 is movably connected to the lower screw connector 12 through the bearing assembly 5. The lower end of the rotating pump barrel 7 is provided with a pump barrel lower connector 13 for connecting with the drill bit 15. The rotation of the rotating pump barrel 7 drives the drill bit 15 to rotate to achieve the drilling action.

[0027] The difference from Example 1 is: Reference Figure 5 and Figure 6 The rotary pump barrel 7 mentioned in this invention has auxiliary vanes 10 installed on its outer wall. The auxiliary vanes 10 have a helical structure and are evenly distributed on the outer wall of the rotary pump barrel 7. The direction of rotation of the auxiliary vanes 10 is opposite to the direction of rotation of the helical groove of the fixed screw 2. In use, when the drill bit 15 is drilling, the upward-moving mud helps to drive the rotation of the rotary pump barrel 7, which not only increases the torsional resistance of the rotary pump barrel 7, but also improves the torque of the rotary pump barrel 7 and improves the energy utilization efficiency.

[0028] The method of using the high-torque screw drill bit for oil drilling mentioned in this invention includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing 6 is vulcanized and fixed to the inner wall of the rotary pump barrel 7, and the inner wall of the rubber bushing 6 is uniformly provided with a spiral curved surface 6.1. Then, rotary stabilizers 3 are installed on both sides of the outer wall of the rotary pump barrel 7, and fixed and limited by stabilizer retaining rings 8. Then, the fixing screw 2 is installed in the inner cavity of the rotary pump barrel 7, the upper end of the fixing screw 2 is connected to the upper screw connector 1, and the lower end of the fixing screw 2 is connected to the lower screw connector 12. Then, the bearing assembly 5 and the upper sealing cap 4 are installed in the annular space between the inner wall of the rotary pump barrel 7 and the upper screw connector 1, and the bearing assembly 5 and the lower fixing cap 9 are installed in the annular space between the inner wall of the rotary pump barrel 7 and the lower screw connector 12. II. Application of High-Torque Screw Drill Strings for Oil Drilling Reference Figure 7 A screw connector 1 is connected to the lower end of the coiled tubing 14. The high-torque screw drill tool for oil drilling is sent into the well through the coiled tubing 14. The rotary stabilizer 3 acts as a stabilizer for the rotary pump barrel 7. Then, high-pressure power fluid is injected into the coiled tubing 14 at the wellhead. The high-pressure power fluid enters the screw connector 1 through the coiled tubing 14, and then enters the spiral sealing cavity formed by the helical curved surface 6.1 of the rubber bushing 6 and the helical groove of the fixed screw 2 through the high-pressure fluid flow channel 2.1. The fixed screw 2 acts as the stator and the rotary pump barrel 7 acts as the rotor, completing the conversion of liquid pressure energy into mechanical energy, realizing the rotation of the rotary pump barrel 7, which in turn drives the drill bit 15 connected to the lower end of the rotary pump barrel 7 to rotate, realizing the drilling action of the drill bit 15. Since the diameter of the rotary pump barrel 7 is larger than the diameter of the fixed screw 2, the torque of the screw drill tool is greatly improved. Additionally, refer to Figure 6 Because multiple sets of external centralizing blocks 3.6 and fluid passages 3.5 are evenly distributed on the outer wall of the outer centralizing body 3.4 of the rotary centralizer 3, after the high-pressure power fluid drives the rotary pump barrel 7 to rotate, it continues to spray downward through the end of the drill bit 15. The sand and gravel generated by the drill bit 15 are mixed with the high-pressure power fluid to form mud, which then moves upward along the fluid passages 3.5 of the rotary centralizer 3. Because the spiral-shaped auxiliary vanes 10 are installed on the outer wall of the rotary pump barrel 7, the upward-moving mud helps to drive the rotation of the rotary pump barrel 7, further improving the torque transmission of the rotary pump barrel 7. Finally, the mud is discharged upward to the surface along the annulus between the coiled tubing 14 and the wellbore 16.

[0029] The above description is merely a partial preferred embodiment of the present invention. Any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, any simple modifications or equivalent transformations made based on the technical solutions of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A high-torque screw drill bit for oil drilling, comprising a screw upper connector (1), characterized in that: It also includes a fixed screw (2), a rotary stabilizer (3), a bearing assembly (5), a rubber bushing (6), a rotary pump barrel (7), a stabilizer retaining ring (8), a screw lower connector (12), and a pump barrel lower connector (13). The upper end of the fixed screw (2), which serves as the stator, is equipped with a screw upper connector (1) for connection to the continuous oil pipe (14). The rotary pump barrel (7), which serves as the rotor, is fitted on the outer wall of the fixed screw (2). The inner wall of the rotary pump barrel (7) is vulcanized with a fixed rubber bushing (6). The rubber bushing (6) has a uniformly distributed helical curved surface (6.1) for meshing with the helical groove on the outer wall of the fixed screw (2) to form a helical sealing cavity. The rotary pump barrel (7) Rotary stabilizers (3) are installed on the upper and lower sides of the outer wall respectively, and the two sides of the rotary stabilizers (3) are limited by the installation of stabilizer retaining rings (8). The inner wall of the rotary stabilizer (3) is movably connected to the outer wall of the end of the rotary pump barrel (7). The inner wall of the upper end of the rotary pump barrel (7) is movably connected to the upper screw connector (1) through the bearing assembly (5), and the inner wall of the lower end of the rotary pump barrel (7) is movably connected to the lower screw connector (12) through the bearing assembly (5). The lower end of the rotary pump barrel (7) is provided with a pump barrel lower connector (13) for connecting with the drill bit (15). The drilling action is achieved by rotating the rotary pump barrel (7) to drive the drill bit (15) to rotate.

2. The high-torque screw drill bit for oil drilling according to claim 1, characterized in that: The upper sealing cap (4) is installed on the upper side of the bearing assembly (5) at the upper end of the rotary pump barrel (7), and the sealing retaining ring (11) is installed on the lower side of the bearing assembly (5); the lower fixing cap (9) is installed on the lower side of the bearing assembly (5) at the lower end of the rotary pump barrel (7), and the sealing retaining ring (11) is installed on the upper side of the bearing assembly (5).

3. The high-torque screw drill bit for oil drilling according to claim 2, characterized in that: The rotary stabilizer (3) includes an inner cylinder (3.1), a rotary bearing (3.2), an outer stabilizer body (3.4), a liquid passage groove (3.5), and an outer stabilizer block (3.6). The inner wall of the inner cylinder (3.1) is connected and fixed to the outer wall of the rotary pump cylinder (7). The outer wall of the inner cylinder (3.1) is movably connected to the outer stabilizer body (3.4) through multiple sets of rotary bearings (3.2). A rotary seal (3.3) is installed at the outer end of the rotary bearing (3.2). Multiple sets of outer stabilizer blocks (3.6) and multiple sets of liquid passage grooves (3.5) are evenly distributed on the outer wall of the outer stabilizer body (3.4), and the outer stabilizer blocks (3.6) and liquid passage grooves (3.5) are arranged at intervals.

4. The high-torque screw drill bit for oil drilling according to claim 3, characterized in that: The inner wall center of the outer straightening body (3.4) is provided with an inner protrusion ring (3.4.1), and multiple sets of rotary bearings (3.2) are installed on the upper and lower sides of the inner protrusion ring (3.4.1). The multiple sets of rotary bearings (3.2) slide in cooperation with the outer wall of the inner cylinder (3.1); the outer sides of both ends of the outer straightening body (3.4) are respectively provided with chamfers (3.4.2).

5. The high-torque screw drill bit for oil drilling according to claim 4, characterized in that: The rotary pump barrel (7) includes a pump barrel body (7.1), an upper bearing assembly mounting part (7.2), an upper pressure cap thread (7.3), a retaining ring thread (7.4), a lower bearing assembly mounting part (7.5), and a lower pressure cap thread (7.6). A rubber bushing (6) is injected into the inner wall of the middle part of the pump barrel body (7.1). The upper end of the pump barrel body (7.1) is provided with an upper bearing assembly mounting part (7.2) and an upper pressure cap thread (7.3). The lower end of the pump barrel body (7.1) is provided with a lower bearing assembly mounting part (7.5) and a lower pressure cap thread (7.6). Two sets of retaining ring threads (7.4) are provided on both sides of the outer wall of the pump barrel body (7.1) for installing the centralizer retaining ring (8).

6. The high-torque screw drill bit for oil drilling according to claim 5, characterized in that: The upper end of the fixed screw (2) is provided with a high-pressure liquid flow channel (2.1). The high-pressure liquid enters the upper joint (1) of the screw along the continuous oil pipe (14), and then enters the spiral sealing cavity formed by the spiral curved surface (6.1) in the rubber bushing (6) and the spiral groove on the outer wall of the fixed screw (2) through the high-pressure liquid flow channel (2.1), thereby driving the rotary pump barrel (7) to rotate.

7. The high-torque screw drill bit for oil drilling according to claim 5, characterized in that: The outer wall of the rotary pump cylinder (7) is provided with auxiliary vanes (10), which are spiral structures and are evenly distributed on the outer wall of the rotary pump cylinder (7).

8. The high-torque screw drill bit for oil drilling according to claim 7, characterized in that: The direction of rotation of the auxiliary blade (10) is opposite to the direction of rotation of the helical groove of the fixed screw (2).

9. The method of using the high-torque screw drill bit for oil drilling according to claim 5, characterized in that: Includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing (6) is vulcanized and fixed to the inner wall of the rotary pump barrel (7), and the inner wall of the rubber bushing (6) is uniformly provided with a spiral curved surface (6.1). Then, rotary stabilizers (3) are installed on both sides of the outer wall of the rotary pump barrel (7), and fixed and limited by stabilizer retaining rings (8). Then, the fixing screw (2) is installed in the inner cavity of the rotary pump barrel (7), the upper end of the fixing screw (2) is connected to the upper screw connector (1), the lower end of the fixing screw (2) is connected to the lower screw connector (12), the bearing assembly (5) and the upper sealing cap (4) are installed in the annular space between the inner wall of the rotary pump barrel (7) and the upper screw connector (1), and the bearing assembly (5) and the lower fixing cap (9) are installed in the annular space between the inner wall of the rotary pump barrel (7) and the lower screw connector (12). II. Application of high-torque screw drill bits for oil drilling: A screw connector (1) is connected to the lower end of the coiled tubing (14). The high-torque screw drill bit for oil drilling is sent into the well through the coiled tubing (14). The rotary stabilizer (3) plays the role of stabilizing the rotary pump barrel (7). Then, high-pressure power fluid is injected into the coiled tubing (14) at the wellhead. The high-pressure power fluid enters the screw connector (1) through the coiled tubing (14) and then enters the spiral sealing cavity formed by the spiral curved surface (6.1) of the rubber bushing (6) and the spiral groove of the fixed screw (2) through the high-pressure fluid flow channel (2.1). The fixed screw (2) serves as the stator and the rotary pump barrel (7) serves as the rotor. The conversion of liquid pressure energy into mechanical energy is completed, and the rotation of the rotary pump barrel (7) is realized. This drives the drill bit (15) connected to the lower end of the rotary pump barrel (7) to rotate, thus realizing the drilling action of the drill bit (15). In addition, since multiple sets of external centralizing blocks (3.6) and fluid passage grooves (3.5) are evenly distributed on the outer wall of the outer centralizing body (3.4) of the rotary centralizer (3), after the high-pressure power fluid drives the rotary pump barrel (7) to rotate, it continues to spray downward through the end of the drill bit (15). The sand and gravel generated by the drill bit (15) are mixed with the high-pressure power fluid to form mud, and then move upward along the fluid passage groove (3.5) of the rotary centralizer (3). Finally, the mud is discharged upward to the surface along the annulus between the coiled tubing (14) and the wellbore (16).

10. The method of using the high-torque screw drill bit for oil drilling according to claim 8, characterized in that: Includes the following steps: I. Assembling high-torque screw drill bits for oil drilling First, the rubber bushing (6) is vulcanized and fixed to the inner wall of the rotary pump barrel (7), and the inner wall of the rubber bushing (6) is uniformly provided with a spiral curved surface (6.1). Then, rotary stabilizers (3) are installed on both sides of the outer wall of the rotary pump barrel (7), and fixed and limited by stabilizer retaining rings (8). Then, the fixing screw (2) is installed in the inner cavity of the rotary pump barrel (7), the upper end of the fixing screw (2) is connected to the upper screw connector (1), the lower end of the fixing screw (2) is connected to the lower screw connector (12), the bearing assembly (5) and the upper sealing cap (4) are installed in the annular space between the inner wall of the rotary pump barrel (7) and the upper screw connector (1), and the bearing assembly (5) and the lower fixing cap (9) are installed in the annular space between the inner wall of the rotary pump barrel (7) and the lower screw connector (12). II. Application of high-torque screw drill bits for oil drilling: A screw connector (1) is connected to the lower end of the coiled tubing (14). The high-torque screw drill string for oil drilling is sent into the well through the coiled tubing (14). The rotary stabilizer (3) acts as a stabilizer for the rotary pump barrel (7). Then, high-pressure power fluid is injected into the coiled tubing (14) at the wellhead. The high-pressure power fluid enters the screw connector (1) through the coiled tubing (14) and then enters the helical surface (6.1) of the rubber bushing (6) through the high-pressure fluid flow channel (2.1). In the spiral sealing cavity formed by the spiral groove of the fixed screw (2), the fixed screw (2) acts as the stator and the rotary pump barrel (7) acts as the rotor, completing the conversion of liquid pressure energy into mechanical energy, realizing the rotation of the rotary pump barrel (7), which in turn drives the drill bit (15) connected to the lower end of the rotary pump barrel (7) to rotate, realizing the drilling action of the drill bit (15). Since the diameter of the rotary pump barrel (7) is larger than the diameter of the fixed screw (2), the torque of the screw drill tool is greatly improved. In addition, since multiple sets of external centralizing blocks (3.6) and fluid passage grooves (3.5) are evenly distributed on the outer wall of the outer centralizing body (3.4) of the rotary centralizer (3), after the high-pressure power fluid drives the rotary pump barrel (7) to rotate, it continues to spray downward through the end of the drill bit (15). The sand and gravel generated by the drill bit (15) are mixed with the high-pressure power fluid to form mud, and then move upward along the fluid passage groove (3.5) of the rotary centralizer (3). Since the spiral-shaped auxiliary blades (10) are installed on the outer wall of the rotary pump barrel (7), the upward-moving mud helps to drive the rotation of the rotary pump barrel (7), further improving the torque transmission of the rotary pump barrel (7). Finally, the mud is discharged upward to the surface along the annulus between the coiled tubing (14) and the wellbore (16).

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