High-torque screw drill for oil drilling and method of use

Abstract

The application relates to a downhole power drilling tool for oil drilling, in particular to a high-torque screw drilling tool for oil drilling and a use method. The technical scheme is as follows: a rotating pump barrel serving as a rotor is sleeved with the outer wall of a fixed screw serving as a stator, the inner wall of the rotating pump barrel is vulcanized with a rubber bushing, the rubber bushing is uniformly distributed with spiral curved surfaces for engaging with the spiral groove of the outer wall of the fixed screw to form a spiral sealing cavity; a rotating centralizer is installed outside the rotating pump barrel, the lower end of the rotating pump barrel is provided with a pump barrel lower connector for being connected with a drill bit, and the rotating pump barrel is rotated to drive the drill bit to rotate to realize drilling. The application has the beneficial effects that the rotating pump barrel is used as the rotor of the screw drilling, the fixed screw is used as the stator of the screw drilling, and the drill bit is connected with the lower end of the rotating pump barrel, so that the maximization of the torque of the screw drilling tool is improved under the limited size of the wellbore, and the drill bit can meet the needs of more scenes.

Description

TECHNICAL FIELD

[0001] The present application relates to a downhole power drilling tool for oil drilling, in particular to a high-torque screw drilling tool for oil drilling and a use method thereof. BACKGROUND

[0002] The liquid-driven downhole power drilling tool, also known as downhole motor or power machine, is a drilling tool specially designed for downhole power drilling, and its core function is to convert the liquid energy on the ground into mechanical energy in the downhole, and then drive the drill bit to generate torque to break the rock. This drilling method is called downhole power drilling. Its working principle is: when the high-pressure drilling fluid enters the screw drilling tool, it will be extruded through the spiral channel between the stator (pump cylinder) and the rotor (screw); this process will form alternating high-pressure and low-pressure chambers between the stator and the rotor; due to the pressure difference, the rotor will produce eccentric displacement, i.e. eccentric torque; as the drilling fluid continues to flow down, new high-pressure and low-pressure chambers are continuously generated, which continuously push the rotor to displace under the action of pressure difference; in this way, the rotor continuously rotates in the screw drilling tool and generates mechanical energy. In short, when the drilling fluid flows through the motor, the pressure difference between the inlet and outlet drives the rotation of the rotor, and then the torque and rotational speed are transmitted to the drill bit through the universal shaft and transmission shaft, realizing the conversion of pressure energy of liquid to mechanical energy.

[0003] However, the existing technology has the following problems: the rotor (screw) is in the inner cavity of the stator (pump cylinder), which determines that the cross-sectional outer diameter of the screw is smaller than the cross-sectional inner diameter of the pump cylinder. Since the drill bit connected below will inevitably encounter rock layers during drilling, it is desirable to have a larger torque of the drill bit. The torque of the drill bit comes from the torque transmitted by the screw. The existing screw is made of high-strength steel, so theoretically, the torque can only be increased by machining a thicker screw, which results in a larger size of the screw drilling tool. The size of the wellbore limits the upper limit of the size of the screw drilling tool. Therefore, how to further increase the torque of the rotor (screw) is a problem to be solved.

[0004] In addition, it should be noted that the diameter of the shaft and the relationship of the transmitted torque are as follows: the diameter of the shaft has a crucial influence on the torque it can transmit. According to the principle of mechanics, torque is the force that causes the shaft to rotate, and the shaft needs to have sufficient strength and stiffness to withstand and transmit this torque. The larger the diameter of the shaft, the stronger its torsional resistance, and the greater the torque it can transmit. This is because the torsional section modulus of the shaft is proportional to the cube of the diameter. Simply put, the torsional section modulus is an index that measures the shaft's resistance to torsional failure. The larger the value, the less likely the shaft is to deform or fail when subjected to torque. SUMMARY

[0005] The oil drilling high-torque screw drill and the use method aim at the above-mentioned defects in the prior art, and the rotation type pump barrel is used as a rotor of the screw drilling, the fixed screw is used as a stator of the screw drilling, and the drill bit is connected to the lower end of the rotation type pump barrel, so that the torque of the screw drill is maximized in the limited size of the wellbore, and the drill bit meets more scene needs.

[0006] The oil drilling high-torque screw drill provided by the application has the technical scheme that the fixed screw is used as a stator, the rotation type pump barrel is used as a rotor, the drill bit is connected to the lower end of the rotation type pump barrel, and the torque of the screw drill is maximized in the limited size of the wellbore.

[0007] Preferably, the upper side of the bearing set at the upper end of the rotation type pump barrel is provided with an upper sealing pressure cap, and the lower side of the bearing set is provided with a sealing stop ring; the lower side of the bearing set at the lower end of the rotation type pump barrel is provided with a lower fixed pressure cap, and the upper side of the bearing set is provided with a sealing stop ring.

[0008] Preferably, the rotation type centralizer includes an inner cylinder body, a rotating bearing, an outer centralizer main body, a liquid passing groove, and an outer centralizer block.

[0009] Preferably, the inner wall of the outer centralizer main body is provided with an inner protruding ring, a plurality of rotating bearings are arranged on the upper side and the lower side of the inner protruding ring, the plurality of rotating bearings are in sliding fit with the outer wall of the inner cylinder body, and the outer side of the two ends of the outer centralizer main body is provided with a chamfer.

[0010] Preferably, the rotating pump barrel comprises a pump barrel body, an upper bearing set mounting portion, an upper pressure cap thread, a retaining ring thread, a lower bearing set mounting portion, a lower pressure cap thread, a rubber bushing is injection molded on the inner wall of the middle portion of the pump barrel body, the upper end of the pump barrel body is provided with the upper bearing set mounting portion and the upper pressure cap thread, the lower end of the pump barrel body is provided with the lower bearing set mounting portion and the lower pressure cap thread, and two groups of retaining ring threads are arranged on the outer wall of the pump barrel body, for mounting the centralizer retaining ring.

[0011] Preferably, the upper end of the fixed screw is provided with a high-pressure liquid flow channel, high-pressure liquid enters the screw upper joint along the coiled tubing, and then enters the spiral sealing cavity formed by the spiral curved surface in the rubber bushing and the helical groove on the outer wall of the fixed screw through the high-pressure liquid flow channel, to push the rotating pump barrel to rotate.

[0012] Preferably, the outer wall of the rotating pump barrel is provided with auxiliary rotating vanes, the auxiliary rotating vanes are in a spiral structure and are uniformly distributed on the outer wall of the rotating pump barrel.

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

[0014] The use method of the high-torque screw drill for oil drilling mentioned in the application comprises the following steps:

[0015] I. Assembling the high-torque screw drill for oil drilling

[0016] First, the rubber bushing is vulcanized and fixed on the inner wall of the rotating pump barrel, and the inner wall of the rubber bushing is uniformly provided with a spiral curved surface, then the rotating centralizer is mounted on the outer wall of the rotating pump barrel, and the centralizer retaining ring is fixed and limited; then, the fixed screw is mounted in the inner cavity of the rotating pump barrel, the screw upper joint is connected to the upper end of the fixed screw, the screw lower joint is connected to the lower end of the fixed screw, the bearing set and the upper sealing pressure cap are mounted in the annulus between the inner wall of the rotating pump barrel and the screw upper joint, and the bearing set and the lower fixed pressure cap are mounted in the annulus between the inner wall of the rotating pump barrel and the screw lower joint.

[0017] II. Use of the high-torque screw drill for oil drilling

[0018] The high-torque screw drilling tool for oil drilling is sent into the well through the coiled tubing by connecting the screw upper joint on the lower end of the coiled tubing, and the rotary centralizer plays the centralizing role of the rotary pump cylinder; then, the high-pressure power liquid is injected into the coiled tubing at the ground wellhead, the high-pressure power liquid enters the screw upper joint through the coiled tubing, and then enters the spiral sealing cavity formed by the spiral curved surface of the rubber bushing and the helical groove of the fixed screw through the high-pressure liquid flow channel, the fixed screw serves as a stator, and the rotary pump cylinder serves as a rotor, so that the conversion from the liquid pressure energy to the mechanical energy is completed, the rotation of the rotary pump cylinder is realized, and then the drill bit connected to the lower end of the rotary pump cylinder is rotated to realize the drilling action of the drill bit.

[0019] In addition, since the outer walls of the outer centralizing bodies of the rotary centralizers are uniformly distributed with multiple groups of outer centralizing blocks and liquid passing grooves, after the high-pressure power liquid drives the rotary pump cylinder to rotate, the high-pressure power liquid continues to be sprayed out through the end of the drill bit, the sand and stones generated by the drilling of the drill bit are mixed with the high-pressure power liquid to form mud liquid, and then the mud liquid moves upward along the liquid passing grooves of the rotary centralizers in the reverse direction, and finally, the mud liquid is discharged upward to the ground along the annulus between the coiled tubing and the wellbore.

[0020] The use method of the high-torque screw drilling tool for oil drilling mentioned in the application comprises the following steps:

[0021] I. Assembling the high-torque screw drilling tool for oil drilling

[0022] Firstly, the rubber bushing is vulcanized and fixed on the inner wall of the rotary pump cylinder, and the inner wall of the rubber bushing is uniformly provided with a spiral curved surface, then the rotary centralizers are installed on both sides of the outer wall of the rotary pump cylinder, and are fixed and limited by the centralizer stop ring, then the fixed screw is installed in the inner cavity of the rotary pump cylinder, the screw upper joint is connected to the upper end of the fixed screw, the screw lower joint is connected to the lower end of the fixed screw, the bearing set and the upper sealing pressure cap are installed in the annulus between the inner wall of the rotary pump cylinder and the screw upper joint, and the bearing set and the lower fixed pressure cap are installed in the annulus between the inner wall of the rotary pump cylinder and the screw lower joint.

[0023] II. Use of the high-torque screw drilling tool for oil drilling

[0024] The screw upper joint is connected to the lower end of the coiled tubing, the high-torque screw drilling tool for oil drilling is sent into the well through the coiled tubing, and the rotary centralizer plays a centralizing role of the rotary pump cylinder; then, the high-pressure power liquid is injected into the coiled tubing at the ground wellhead, the high-pressure power liquid enters the screw upper joint through the coiled tubing, and then enters the spiral sealing cavity formed by the spiral curved surface of the rubber bushing and the helical groove of the fixed screw through the high-pressure liquid flow channel; the fixed screw serves as a stator, and the rotary pump cylinder serves as a rotor, so that the conversion from liquid pressure energy to mechanical energy is completed, the rotation of the rotary pump cylinder is realized, the drill bit connected to the lower end of the rotary pump cylinder is rotated, and the drilling action of the drill bit is realized; since the diameter of the rotary pump cylinder is larger than that of the fixed screw, the torque of the screw drilling tool is greatly improved;

[0025] In addition, since the outer walls of the outer centralizing bodies of the rotary centralizers are uniformly distributed with multiple groups of outer centralizing blocks and liquid passing grooves, after the high-pressure power liquid drives the rotary pump cylinder to rotate, the high-pressure power liquid continues to be sprayed out through the end of the drill bit, the sand and stones generated by the drilling of the drill bit are mixed with the high-pressure power liquid to form mud liquid, and then the mud liquid moves upward along the liquid passing grooves of the rotary centralizers in a reverse direction; since the helical auxiliary rotating blades are arranged on the outer walls of the rotary pump cylinders, the upwardly moving mud liquid assists in driving the rotation of the rotary pump cylinder, the transmission of the torque of the rotary pump cylinder is further improved, and finally, the mud liquid is discharged upward along the annulus between the coiled tubing and the wellbore to the ground.

[0026] Compared with the prior art, the beneficial effects of the present application are as follows:

[0027] Firstly, by taking the rotary pump cylinder as the rotor of the screw drilling and taking the fixed screw as the stator of the screw drilling, the diameter of the rotor is larger than the outer diameter of the stator after the rotor and the stator are interchanged, so that the numerical value of the diameter of the rotary pump cylinder for transmitting torque is increased, the torque of the screw drilling under the limited wellbore size is improved, and the drill bit is driven to meet more scene needs;

[0028] Secondly, by taking the rotary pump cylinder as the rotor of the screw drilling and taking the fixed screw as the stator of the screw drilling, the rotor and the stator are interchanged, so that it is possible to add auxiliary rotating blades to the outer walls of the rotary pump cylinders, and after the auxiliary rotating blades are added, not only the torsional resistance of the rotary pump cylinder is increased, but also the transmission of the torque of the rotary pump cylinder is improved, and the utilization efficiency of energy is improved;

[0029] Thirdly, by installing the rotary centralizers on both sides of the outer walls of the rotary pump cylinders, not only the normal rotation of the rotary pump cylinders is ensured, but also the damage of the rotary pump cylinders to the inner walls of the wellbores is avoided, and the damage of the fixed centralizers to the inner walls of the wellbores is also avoided.

[0030] Four, due to the torque of the screw drill, combined with the use of coiled tubing, the drilling operation can be easily realized, thereby shortening the drilling time and saving a large amount of cost. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is the overall structure schematic diagram of embodiment 1 of the present application;

[0032] Figure 2 is the partial cross-sectional schematic diagram of the rotary centralizer;

[0033] Figure 3 is the structure schematic diagram of the rotary centralizer in the overhead direction;

[0034] Figure 4 is the structure schematic diagram of the rotary pump barrel;

[0035] Figure 5 is the structure schematic diagram of the rotary pump barrel externally mounted with auxiliary rotating blades;

[0036] Figure 6 is the overall structure schematic diagram of embodiment 2 of the present application;

[0037] Figure 7 is the schematic diagram of the construction of the present application;

[0038] In the figure: screw upper joint 1, fixed screw 2, rotary centralizer 3, upper sealing pressure cap 4, bearing set 5, rubber bushing 6, rotary pump barrel 7, centralizer blocking ring 8, lower fixed pressure cap 9, auxiliary rotating blade 10, sealing blocking ring 11, screw lower joint 12, pump barrel lower joint 13, coiled tubing 14, drill bit 15, borehole 16, high-pressure liquid flow channel 2.1, inner barrel body 3.1, rotary bearing 3.2, rotary sealing body 3.3, outer centralizer main body 3.4, liquid passing groove 3.5, outer centralizer block 3.6, inner protruding ring 3.4.1, chamfer 3.4.2, spiral curved surface 6.1, pump barrel main body 7.1, upper bearing set mounting part 7.2, upper pressure cap thread 7.3, blocking ring thread 7.4, lower bearing set mounting part 7.5, lower pressure cap thread 7.6. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present application are described below in conjunction with the accompanying drawings, and it should be understood that the preferred embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0040] Embodiment 1, refer to Figures 1-4 , Figure 7The application discloses a high-torque screw drill for oil drilling, and relates to the technical scheme that the screw drill comprises a screw upper joint 1, wherein, the screw drill further comprises a fixed screw 2, a rotating centralizer 3, a bearing set 5, a rubber bushing 6, a rotating pump cylinder 7, a centralizer blocking ring 8, a screw lower joint 12 and a pump cylinder lower joint 13; the upper end of the fixed screw 2 serving as a stator is provided with the screw upper joint 1 for being connected with a coiled tubing 14; the outer wall of the fixed screw 2 is sleeved with the rotating pump cylinder 7 serving as a rotor; the inner wall of the rotating pump cylinder 7 is vulcanized with the rubber bushing 6; the rubber bushing 6 is uniformly distributed with spiral curved surfaces 6.1 for being engaged with the spiral groove of the outer wall of the fixed screw 2 to form a spiral sealing cavity; the upper and lower sides of the outer wall of the rotating pump cylinder 7 are respectively provided with the rotating centralizer 3; the two sides of the rotating centralizer 3 are limited by the centralizer blocking ring 8; the inner wall of the rotating centralizer 3 is movably connected with the outer wall of the end of the rotating pump cylinder 7; the inner wall of the upper end of the rotating pump cylinder 7 is movably connected with the screw upper joint 1 through the bearing set 5; the inner wall of the lower end of the rotating pump cylinder 7 is movably connected with the screw lower joint 12 through the bearing set 5; the lower end of the rotating pump cylinder 7 is provided with the pump cylinder lower joint 13 for being connected with a drill bit 15; the rotating pump cylinder 7 is rotated to drive the drill bit 15 to rotate to realize drilling.

[0041] The upper side of the bearing set 5 of the upper end of the rotating pump cylinder 7 is provided with the upper sealing pressure cap 4, and the lower side of the bearing set 5 is provided with the sealing blocking ring 11; the lower side of the bearing set 5 of the lower end of the rotating pump cylinder 7 is provided with the lower fixed pressure cap 9, and the upper side of the bearing set 5 is provided with the sealing blocking ring 11.

[0042] Referring to Figure 2 and Figure 3 The rotating centralizer 3 comprises an inner cylinder body 3.1, a rotating bearing 3.2, an outer centralizer main body 3.4, a liquid passing groove 3.5 and an outer centralizer block 3.6; the inner wall of the inner cylinder body 3.1 is connected and fixed with the outer wall of the rotating pump cylinder 7; the outer wall of the inner cylinder body 3.1 is movably connected with the outer centralizer main body 3.4 through a plurality of rotating bearings 3.2; the rotating sealing body 3.3 is installed at the outer end of the rotating bearing 3.2; a plurality of outer centralizer blocks 3.6 and a plurality of liquid passing grooves 3.5 are uniformly distributed on the outer wall of the outer centralizer main body 3.4, and the outer centralizer blocks 3.6 and the liquid passing grooves 3.5 are arranged at intervals.

[0043] The inner wall center of the outer centralizer main body 3.4 is provided with an inner protruding ring 3.4.1; a plurality of rotating bearings 3.2 are installed on the upper side and the lower side of the inner protruding ring 3.4.1; the plurality of rotating bearings 3.2 are slidably matched with the outer wall of the inner cylinder body 3.1; the outer sides of the two ends of the outer centralizer main body 3.4 are respectively provided with chamfers 3.4.2, so that the damage of the outer centralizer main body 3.4 to the well wall when the outer centralizer main body 3.4 moves in the well is reduced.

[0044] Referring to Figure 4The rotating pump barrel 7 mentioned in the application comprises a pump barrel body 7.1, an upper bearing set mounting portion 7.2, an upper pressing cap thread 7.3, a retaining ring thread 7.4, a lower bearing set mounting portion 7.5, a lower pressing cap thread 7.6, a rubber bushing 6 is arranged in the middle inner wall of the pump barrel body 7.1, the upper end of the pump barrel body 7.1 is provided with the upper bearing set mounting portion 7.2 and the upper pressing cap thread 7.3, the lower end of the pump barrel body 7.1 is provided with the lower bearing set mounting portion 7.5 and the lower pressing cap thread 7.6, and two groups of retaining ring threads 7.4 are arranged on the outer wall of the pump barrel body 7.1 respectively, for mounting the centralizer retaining ring 8.

[0045] The upper end of the fixed screw 2 is provided with a high-pressure liquid flow channel 2.1, high-pressure liquid enters the screw upper joint 1 along the coiled tubing 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, to push the rotating pump barrel 7 to rotate.

[0046] The method for using the high-torque screw drill for oil drilling mentioned in the application comprises the following steps:

[0047] I. Assembling the high-torque screw drill for oil drilling

[0048] First, the rubber bushing 6 is vulcanized and fixed on the inner wall of the rotating pump barrel 7, and the inner wall of the rubber bushing 6 is uniformly provided with a spiral curved surface 6.1, then the rotating centralizer 3 is mounted on the outer wall of the rotating pump barrel 7 respectively, and is fixed and limited by the centralizer retaining ring 8; then, the fixed screw 2 is installed in the inner cavity of the rotating pump barrel 7, the screw upper joint 1 is connected to the upper end of the fixed screw 2, the screw lower joint 12 is connected to the lower end of the fixed screw 2, the bearing set 5 and the upper sealing pressing cap 4 are installed in the annulus between the inner wall of the rotating pump barrel 7 and the screw upper joint 1, and the bearing set 5 and the lower fixed pressing cap 9 are installed in the annulus between the inner wall of the rotating pump barrel 7 and the screw lower joint 12;

[0049] II. Use of the high-torque screw drill for oil drilling

[0050] Reference Figure 7A 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.

[0051] 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.

[0052] 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.

[0053] The difference from Example 1 is:

[0054] Reference Figure 5 and Figure 6The outer wall of the rotary pump barrel 7 is provided with auxiliary spiral blades 10, which are uniformly distributed on the outer wall of the rotary pump barrel 7 and have a spiral structure; the rotation direction of the auxiliary spiral blades 10 is opposite to that of the helical groove of the fixed screw 2.

[0055] The method for using the high-torque screw drill for oil drilling comprises the following steps:

[0056] I. Assembling the high-torque screw drill for oil drilling

[0057] First, the rubber bushing 6 is vulcanized and fixed on 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 the rotary centralizer 3 is installed on both sides of the outer wall of the rotary pump barrel 7, and is fixed and limited by the centralizer retainer 8; then the fixed screw 2 is installed in the inner cavity of the rotary pump barrel 7, the screw upper joint 1 is connected to the upper end of the fixed screw 2, the screw lower joint 12 is connected to the lower end of the fixed screw 2, the bearing set 5 and the upper sealing gland 4 are installed in the annulus between the inner wall of the rotary pump barrel 7 and the screw upper joint 1, and the bearing set 5 and the lower fixed gland 9 are installed in the annulus between the inner wall of the rotary pump barrel 7 and the screw lower joint 12.

[0058] II. Use of the high-torque screw drill for oil drilling

[0059] Reference Figure 7 The screw upper joint 1 is connected to the lower end of the coiled tubing 14, the high-torque screw drill for oil drilling is sent into the well through the coiled tubing 14, and the rotary centralizer 3 plays a centralizing role of the rotary pump barrel 7; then high-pressure power liquid is injected into the coiled tubing 14 at the ground wellhead, the high-pressure power liquid enters the screw upper joint 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 helical groove of the fixed screw 2 through the high-pressure liquid flow channel 2.1, the fixed screw 2 acts as a stator, and the rotary pump barrel 7 acts as a rotor, thereby completing the conversion of liquid pressure energy into mechanical energy and 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 and realize the drilling action of the drill bit 15; since the diameter of the rotary pump barrel 7 is greater than that of the fixed screw 2, the torque of the screw drill is greatly improved.

[0060] In addition, reference Figure 6Since the outer wall of the outer centralizing body 3.4 of the rotating centralizer 3 is uniformly distributed with multiple groups of outer centralizing blocks 3.6 and liquid passing grooves 3.5, after the high-pressure power liquid drives the rotating pump cylinder 7 to rotate, it continues to be sprayed downward through the end of the drill bit 15, the sandstone produced by the drill bit 15 drills into the high-pressure power liquid to form mud liquid, and then moves upward along the liquid passing grooves 3.5 of the rotating centralizer 3 in the opposite direction. Since the auxiliary rotating blade 10 in the shape of a spiral is arranged on the outer wall of the rotating pump cylinder 7, the upwardly moving mud liquid assists in driving the rotation of the rotating pump cylinder 7, further improving the transmission of the torque of the rotating pump cylinder 7, and finally, the mud liquid is discharged upward along the annulus between the coiled tubing 14 and the borehole 16 to the ground.

[0061] The above is only part of the preferred embodiments of the present application, and any person skilled in the art can modify the above-described technical solutions or modify them into equivalent technical solutions. Therefore, the corresponding simple modifications or equivalent transformations according to the technical solutions of the present application are within the scope of protection claimed by the present application.

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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