An anti-unthreading positive displacement motor for oil drilling operations

Abstract

The present invention discloses a non-back-off screw drill for oil drilling operations. The present invention relates to the technical field of drill tools for oil drilling operations and includes an anti-drop joint, and an anti-drop component is assembled inside the anti-drop joint. For this non-back-off screw drill for oil drilling operations, by adopting a roller multi-row combined thrust bearing in the cylindrical roller bearing assembly, the bearing force area and wear resistance are increased, the overall service life of the screw drill is improved, the flow area of the drilling fluid is increased, the problem of pump jamming when the thread at the lower part of the drill tool breaks is prevented, unpredictable secondary downhole accidents are reduced, the safety and reliability of the screw drill are improved, the problem of the anti-drop back nut becoming unthreaded can be effectively avoided, the anti-drop performance of the anti-drop component inside the anti-drop joint is enhanced, the hidden danger of the overall loosening of the double nut assembly is eliminated, the ball hinge single seal sleeve is changed to a double seal sleeve, which can be sealed for a long time, making the universal shaft have a longer service life, and reducing the probability of thread reverse threading and breakage by half.

Description

Technical Field

[0001] The invention relates to the technical field of drilling tools for oil drilling operations, in particular to an anti-slip screw drilling tool for oil drilling operations. Background Art

[0002] A screw drill is a type of downhole power drilling tool widely used in oil and gas drilling operations. Its structure primarily consists of five major components: a bypass valve assembly, an anti-drop assembly, a motor assembly, a universal joint assembly, and a drive shaft assembly. Mud pumped from the mud pump flows through the bypass valve and into the motor, creating a pressure differential between the motor's inlet and outlet, which drives the motor's rotor. This pressure differential then transmits torque and speed to the drill bit via the universal joint and drive shaft. The performance of a screw drill primarily depends on the motor assembly. Conventional screw drills have four external threads, and each additional thread increases the risk of backlash and breakage. In actual use, these issues often occur, increasing the risk of falling into the well. Therefore, a safe and stable screw drill is needed. This requires a motor assembly with a built-in anti-drop device at the top and a drive shaft assembly at the bottom. The upper and lower parts are connected by an adjustable angle housing in the middle. External connections between the assemblies utilize a screw drill with only two threads to mitigate the various risks mentioned above. Summary of the Invention

[0003] To achieve the above objectives, the present invention is implemented through the following technical solutions: an anti-drop screw drill tool for oil drilling operations, comprising an anti-drop joint, an anti-drop component assembled inside the anti-drop joint, a hoop cavity and a hoop opening extending through the interior of the anti-drop joint, a drive shaft tube installed at the tail end of the anti-drop joint, a motor assembly fixedly installed in the hoop cavity of the anti-drop joint, mud output by a mud pump can flow through a bypass valve into the motor, forming a certain pressure difference between the inlet and outlet of the motor, driving the motor rotor to rotate, and transmitting torque and speed to the drill bit through the universal joint and the drive shaft;

[0004] The anti-drop component is assembled in the interior of the anti-drop joint for conveying mud, and the anti-drop component includes an anti-drop connecting rod, the outer surface of the anti-drop connecting rod is symmetrically provided with a wide groove and a narrow groove, and a chamfered step is provided between the wide groove and the narrow groove, and the wide groove is connected to the narrow groove through the chamfered step, so that the card ball can smoothly transition and slide from the wide groove to the narrow groove, wherein the groove depth of the wide groove is greater than the groove depth of the narrow groove, and the groove width of the wide groove is greater than the groove width of the narrow groove, wherein a ball cover ear is fixedly connected to the outer surface of the anti-drop connecting rod and is arranged at one end away from the narrow groove, and a short cover ear is fixedly connected to the outer surface of the anti-drop connecting rod and is arranged at one end away from the wide groove, the longitudinal extension length of the short cover ear is smaller than the longitudinal extension length of the ball cover ear, wherein the curved surface of the ball cover ear is opposite to the input direction of the mud, and the wide groove, the chamfered step and the narrow groove together constitute a guide rail cavity;

[0005] The anti - detachment component is assembled inside the anti - dropping joint and is arranged away from the near - end port of the anti - dropping joint, and is used to intercept the sliding of the anti - dropping component towards the inside of the anti - dropping joint;

[0006] The double - nut assembly is installed on the anti - dropping connecting rod and at the end away from the anti - detachment ring frame, and is used to limit and block the front end of the anti - dropping connecting rod inside the anti - dropping joint to prevent disengagement;

[0007] The universal - shaft fixing component is assembled at the tail end of the anti - dropping component and is arranged in the hoop cavity of the anti - dropping joint;

[0008] The adjustable universal - shaft assembly is assembled between the anti - dropping joint and the drive - shaft tube and is used to assemble and connect the anti - dropping joint and the drive - shaft tube;

[0009] The cylindrical - roller bearing assembly is installed inside the drive - shaft tube, increasing the bearing force area and wear - resistance strength, and improving the overall service life of the positive - displacement motor.

[0010] Preferably, the anti - detachment component includes an anti - detachment ring frame fixedly installed inside the anti - dropping joint. One end of the anti - detachment ring frame close to the ball - cover ear is fixedly connected with a frustum - shaped ring, which can increase the flow - blocking area for blocking the flowing mud head - on. And two spring rods are symmetrically installed at one end of the anti - detachment ring frame close to the ball - cover ear and are arranged at an inclined angle with respect to the plane where the axis of the anti - detachment ring frame is located. The free end of each spring rod is connected with a clamping ball, and the clamping ball is telescopically installed with the anti - detachment ring frame through the spring rod. The clamping ball is fitted with a wide - slot through the spring rod and can slide back and forth on the anti - dropping connecting rod through the guide - rail cavity.

[0011] Preferably, the double - nut assembly includes a three - claw anti - detachment pad sleeved on the front end of the anti - dropping connecting rod. Side filter holes are equally - arc - length opened on the outer surface of the three - claw anti - detachment pad, and the number is three. And an anti - dropping gasket is sleeved on the front end of the anti - dropping connecting rod. A right - hand - threaded ring is installed at the front end of the anti - dropping gasket and is connected to the anti - dropping connecting rod by right - hand threads. A left - hand - threaded nut is installed at the front end of the right - hand - threaded ring and is connected to the anti - dropping connecting rod by left - hand threads. Among them, the outer diameters of the anti - dropping gasket, the right - hand - threaded ring and the left - hand - threaded nut are all equal and are larger than the inner diameter of the hoop opening, and the diameter of the three - claw anti - detachment pad is larger than the outer diameter of the anti - dropping gasket.

[0012] Preferably, a hexagonal guiding ring is fixedly installed in the hoop cavity of the anti-drop joint, and a hexagonal cavity is penetrated through the middle of the hexagonal guiding ring. The outer diameter of the anti-drop gasket is smaller than the diameter of the hexagonal cavity. When the left threaded cap is aligned with the hexagonal cavity, the front end of the anti-drop connecting rod can be driven to pass through the middle of the hexagonal guiding ring, and at the same time, the hexagonal cavity in the middle of the hexagonal guiding ring guides the input of the mud. The anti-drop connecting rod is integrally installed inside the anti-drop joint through the hoop cavity, and is assembled with the anti-drop joint through the cooperation of the three-claw anti-disconnection pad, the anti-drop gasket, the right threaded ring and the left threaded cap, and is clamped at the hoop opening inside the anti-drop joint; preventing the occurrence of pump choking phenomenon, reducing unpredictable secondary downhole accidents, and increasing the safety factor.

[0013] Preferably, the universal shaft fixing component includes a directional head. One end of the directional head away from the anti-drop connecting rod is fixedly connected with a sealing joint ring, and a connecting piece is installed inside the sealing joint ring. A spherical shaft joint sleeve is assembled on the outer surface of the connecting piece for rotatably clamping the surface of the connecting piece with the inner wall of the sealing joint ring.

[0014] Preferably, a top ball joint is fixedly installed at the end of the connecting piece close to the directional head, and the connecting piece is hinged to the middle of the inner side of the directional head through the top ball joint.

[0015] Preferably, a first sealing bucket cover is fixedly sleeved on the outer surface of the connecting piece, and a sealing inner ring is fixedly connected in a ring shape on the inner wall surface of the first sealing bucket cover. The sealing joint ring is clamped and installed with the first sealing bucket cover through the sealing inner ring, which can play the role of long-term sealing and extending the service life. Among them, the anti-drop connecting rod, the directional head and the motor assembly are all installed in the hoop cavity of the anti-drop joint, and one end of the anti-drop connecting rod away from the hexagonal guiding ring is assembled with the directional head through the motor assembly.

[0016] Preferably, the adjustable universal shaft assembly includes an adjustable joint body. Threaded joints are fixedly connected to the middle parts of the front and rear ends of the adjustable joint body. A connecting thread one is provided at the inner wall of the anti-drop joint where it is assembled with the adjustable joint body. The anti-drop joint is threadedly connected with the adjustable joint body through the cooperation of the connecting thread one and the threaded joint.

[0017] Preferably, a connecting thread two is provided at the inner wall of the drive shaft tube where it is assembled with the adjustable joint body. The drive shaft tube is threadedly connected with the adjustable joint body through the cooperation of the connecting thread two and the threaded joint.

[0018] Preferably, the cylindrical roller bearing assembly includes a first steel ring, a second steel ring is installed on the other side of the first steel ring, and an intermediate ring body is fixedly connected in the middle between the first steel ring and the second steel ring, and rollers and rectangular bars are installed in a circular array inside the intermediate ring body, the rollers are located between the first steel ring and the second steel ring, and are rotatably installed with the intermediate ring body, the rollers and the rectangular bars are staggered on the intermediate ring body, and the rectangular bars are fixedly installed with the intermediate ring body, wherein the rollers protrude from the inner and outer wall surfaces of the intermediate ring body and are exposed on the outside of the projected circular ring where the first steel ring and the second steel ring are located, and can fit tightly with the inner wall of the transmission shaft tube, the rectangular bar as a whole protrudes from the inner wall surface of the intermediate ring body, and is slightly lower than the thickness of the rollers protruding from the inner wall surface of the intermediate ring body, which can prevent the cylindrical roller bearing assembly from being damaged or broken as a whole and blocked in the transmission shaft tube, providing reaction time for timely discovery and replacement of a new cylindrical roller bearing assembly.

[0019] The present invention provides an anti-slip screw drill tool for oil drilling operations, which has the following beneficial effects:

[0020] 1. The anti-tripping screw drill tool for oil drilling operations adopts a roller-type multi-row combined thrust bearing through a cylindrical roller bearing assembly, which increases the bearing force area and wear resistance, improves the overall service life of the screw drill tool, and is used to increase the bearing force area.

[0021] 2. The anti-slip screw drill tool for oil drilling operations, by replacing the traditional disc-shaped anti-slip gasket with a three-claw structure anti-slip gasket, can increase the drilling fluid flow area, prevent the pump blocking problem caused by the breakage of the lower thread of the drill tool, reduce unpredictable secondary downhole accidents, and improve the safety and reliability of the screw drill tool during use.

[0022] 3. The anti-drop screw drill tool for oil drilling operations uses a mud pump to transport mud, which flows through the bypass valve and the anti-drop joint and enters the motor assembly. A certain pressure difference is formed at the inlet and outlet of the motor assembly, which drives the motor rotor to rotate and transmits the torque and speed to the drill bit through the universal joint and the drive shaft. During this use, the anti-drop ring frame and the hexagonal guide ring are used as a limiting structure for the forward and backward movement of the anti-drop component at the clamp position. The forward and backward sliding movement of the cardan balls on the two spring rods in the guide rail cavity is used to cooperate with the anti-drop ring frame and the hexagonal guide ring to prevent the anti-drop component from falling, further enhancing the anti-drop performance of the anti-drop component on the inside of the anti-drop joint. At the same time, the anti-drop component linearly guides the forward and backward movement trajectory of the anti-drop component on the inside of the anti-drop joint, so that the forward and backward movement trajectory always remains at the position corresponding to the left threaded cap and the hexagonal guide ring.

[0023] IV. For the anti-unthreading screw drill for oil drilling operations, through the cooperation of guiding and blocking of the spring rod by the guiding rail cavity and the ball cover ear provided on the surface of the anti-falling connecting rod, the three-claw anti-falling pad will not directly collide with the hoop inside the anti-falling joint under normal working conditions, eliminating the hidden danger of the overall loosening of the double-nut assembly. On the other hand, the side filter holes allow the mud to pass through, and the anti-falling ring frame and the conical ring jointly block and reverse flow part of the oncoming mud, so that the walls of the three-claw anti-falling pad adjacent to the hoop will not easily collide with each other, further avoiding the triggering of the double-nut assembly when the anti-falling connecting rod retracts inside the anti-falling joint.

[0024] V. For the anti-unthreading screw drill for oil drilling operations, the first sealing bucket cover and the sealing inner ring are jointly sleeved on the outer surface of the sealing joint ring. Through the overall tight sleeving of the first sealing bucket cover on the outer surface of the sealing joint ring and the tight clamping of the sealing inner ring by the sealing joint ring inside the first sealing bucket cover, double sealing between the connecting piece and the orienting head is achieved. In this way, the traditional two-end ball-hinged universal shaft is changed to a structure with only one-end ball hinge, and the original single-sealing sleeve of the ball hinge is changed to a double-sealing sleeve, achieving the purpose of long-term sealing and enabling the universal shaft to have a longer service life.

[0025] VI. For the anti-unthreading screw drill for oil drilling operations, when the rollers inside the middle ring body are worn, combined with the relative rotation between the first steel ring and the second steel ring and the inner wall of the transmission shaft tube, the rectangular strip rotates relatively inside the middle ring body to temporarily replace the worn rollers and play a role for a short time, avoiding the overall damage or breakage of the cylindrical roller bearing assembly and blocking inside the transmission shaft tube, providing reaction time for timely discovery and replacement of a new cylindrical roller bearing assembly and providing temporary protection for the inner structure of the transmission shaft tube.

[0026] VII. For the anti-unthreading screw drill for oil drilling operations, by changing the external connection threads between the traditional assemblies from four to two threads, the probability of the threads being reversed and broken is reduced by half. The bypass valve assembly and the anti-falling joint threads are removed, greatly reducing the risk coefficient of the external connection threads being reversed and broken, effectively reducing the risk of the screw drill falling into the well due to reverse threading and broken threading underground, and greatly improving the safety and stability coefficient of underground operations.

[0027] VIII. For the anti-unthreading screw drill for oil drilling operations, by designing the traditional anti-falling back nut with only one thread, that is, the left-handed back nut, into an anti-falling back nut in the form of a double-back nut joint, the threads are processed into left-handed and right-handed, and using the double reverse threads as the structural design for preventing unthreading, the problem of the anti-falling back nut being unthreaded can be effectively avoided, increasing the safety factor. Description of the Drawings

[0028] Figure 1Schematic diagram of the external structure of a non-back-off screw drill for oil drilling operations according to the present invention;

[0029] Figure 2 Half-sectional view of a non-back-off screw drill for oil drilling operations according to the present invention;

[0030] Figure 3 Schematic diagram of the anti-disconnection assembly according to the present invention;

[0031] Figure 4 Schematic diagram of the anti-falling-off assembly according to the present invention;

[0032] Figure 5 Schematic diagram of the double-nut assembly according to the present invention;

[0033] Figure 6 Schematic diagram of the universal joint fixing assembly according to the present invention;

[0034] Figure 7 Schematic diagram of the adjustable universal joint assembly according to the present invention;

[0035] Figure 8 Schematic diagram of the cylindrical roller bearing assembly according to the present invention.

[0036] In the figure: 1. Anti-falling-off joint; 2. Anti-falling-off assembly; 21. Anti-falling-off connecting rod; 22. Wide slotted groove; 23. Narrow slotted groove; 24. Ball cover ear; 25. Rounded step; 26. Short cover ear; 3. Anti-disconnection assembly; 31. Anti-disconnection ring frame; 32. Frustum ring; 33. Locking ball; 34. Spring rod; 4. Motor assembly; 5. Hexagonal guiding ring; 6. Double-nut assembly; 61. Three-claw anti-disconnection pad; 62. Side filter hole; 63. Anti-falling-off gasket; 64. Right-threaded ring; 65. Left-threaded nut; 7. Universal joint fixing assembly; 71. Orienting head; 72. Ball shaft adapter sleeve; 73. Connecting piece; 74. First sealing bucket cover; 75. Sealing inner ring; 76. Sealing joint ring; 77. Top ball joint; 8. Adjustable universal joint assembly; 81. Adjustable joint body; 82. Threaded joint; 83. Connecting thread one; 84. Connecting thread two; 9. Cylindrical roller bearing assembly; 91. First steel ring; 92. Second steel ring; 93. Roller; 94. Rectangular strip; 95. Intermediate ring body; 10. Drive shaft tube. Detailed implementation manners

[0037] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners. The embodiments of the present invention are given for purposes of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are chosen and described in order to best explain the principles of the present invention and its practical applications, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes.

[0038] The first embodiment, as Figures 1 to 8 shown, the present invention provides a technical solution: a non-disengaging screw drill for oil drilling operations, including a non-drop joint 1. An anti-drop component 2 is assembled inside the non-drop joint 1. A hoop cavity and a hoop opening are penetrated and opened inside the non-drop joint 1. A drive shaft tube 10 is installed at the tail end of the non-drop joint 1. A motor assembly 4 is fixedly installed in the hoop cavity of the non-drop joint 1. The mud output by the mud pump can flow through the bypass valve into the motor, forming a certain pressure difference at the inlet and outlet of the motor, pushing the motor rotor to rotate, and transmitting the torque and speed to the drill bit through the universal shaft and the drive shaft, playing a role of mechanical transmission during use;

[0039] The anti-drop component 2 is assembled inside the non-drop joint 1 and is used for conveying mud. The anti-drop component 2 includes an anti-drop connecting rod 21. Wide slots 22 and narrow slots 23 are symmetrically opened on the outer surface of the anti-drop connecting rod 21. A rounded step 25 is provided between the wide slot 22 and the narrow slot 23, and the wide slot 22 is connected to the narrow slot 23 through the rounded step 25, enabling the locking ball 33 to smoothly transition and slide from the wide slot 22 into the narrow slot 23. Among them, the slot depth of the wide slot 22 is greater than that of the narrow slot 23, and the slot width of the wide slot 22 is greater than that of the narrow slot 23. A ball cover ear 24 is fixedly connected to the outer surface of the anti-drop connecting rod 21 and is arranged at one end far from the narrow slot 23. A short cover ear 26 is fixedly connected to the outer surface of the anti-drop connecting rod 21 and is arranged at one end far from the wide slot 22. The longitudinal extension length of the short cover ear 26 is less than that of the ball cover ear 24. Among them, the curved surface of the ball cover ear 24 faces the opposite direction of the mud input direction. The wide slot 22, the rounded step 25, and the narrow slot 23 together form a guiding rail cavity;

[0040] The anti-disengagement component 3 is assembled inside the non-drop joint 1 and is arranged far from the near port of the non-drop joint 1, and is used to intercept the inward sliding of the anti-drop component 2 towards the inside of the non-drop joint 1;

[0041] The double nut assembly 6 is installed on the anti-drop connecting rod 21 and at one end far from the anti-disengagement ring frame 31, and is used to limit and block the front end of the anti-drop connecting rod 21 inside the non-drop joint 1 to prevent disengagement;

[0042] The universal shaft fixing component 7 is assembled at the tail end of the anti-drop component 2 and is arranged in the hoop cavity of the non-drop joint 1;

[0043] The adjustable universal shaft assembly 8 is assembled between the non-drop joint 1 and the drive shaft tube 10 and is used to assemble and connect the non-drop joint 1 and the drive shaft tube 10;

[0044] Cylindrical roller bearing assembly 9, which is installed inside the drive shaft tube 10. It adopts a roller multi-row combined thrust bearing, increasing the bearing force area and wear resistance strength, improving the overall service life of the positive displacement motor, and is used to increase the bearing force area.

[0045] The anti-disengagement assembly 3 includes an anti-disengagement ring frame 31 fixedly installed inside the anti-drop joint 1. One end of the anti-disengagement ring frame 31 close to the ball cover ear 24 is fixedly connected with a frustum ring 32, which can increase the flow resistance area for blocking the mud flow head-on. And two spring rods 34 are symmetrically installed at one end of the anti-disengagement ring frame 31 close to the ball cover ear 24 and are arranged at an inclined angle with respect to the plane where the axis of the anti-disengagement ring frame 31 is located. The free end of each spring rod 34 is connected with a clamping ball 33, and the clamping ball 33 is telescopically installed with the anti-disengagement ring frame 31 through the spring rod 34. The clamping ball 33 is fitted and installed with the wide slot 22 through the spring rod 34 and can slide back and forth on the anti-drop connecting rod 21 through the guide rail cavity.

[0046] The double nut assembly 6 includes a three-claw anti-disengagement pad 61 sleeved on the front end of the anti-drop connecting rod 21. Equal-arc-length side filter holes 62 are opened on the outer surface of the three-claw anti-disengagement pad 61, and the number is three, which can increase the flow area of the drilling fluid to prevent the problem of pump choking when the lower thread of the drill tool breaks, reducing unpredictable secondary downhole accidents. And an anti-drop gasket 63 is sleeved on the front end of the anti-drop connecting rod 21. A right-threaded ring 64 is installed at the front end of the anti-drop gasket 63 and is connected to the anti-drop connecting rod 21 by a right thread. A left-threaded nut 65 is installed at the front end of the right-threaded ring 64 and is connected to the anti-drop connecting rod 21 by a left thread. Among them, the outer diameters of the anti-drop gasket 63, the right-threaded ring 64 and the left-threaded nut 65 are all equal and are larger than the inner diameter of the hoop, and the diameter of the three-claw anti-disengagement pad 61 is larger than the outer diameter of the anti-drop gasket 63.

[0047] A hexagonal guiding ring 5 is fixedly installed in the hoop cavity of the anti-drop joint 1, and a hexagonal cavity is penetrated through the middle of the hexagonal guiding ring 5. The outer diameter of the anti-drop gasket 63 is smaller than the diameter of the hexagonal cavity. When the left-threaded nut 65 is aligned with the hexagonal cavity, it can drive the front end of the anti-drop connecting rod 21 to pass through the middle of the hexagonal guiding ring 5. At the same time, the hexagonal cavity in the middle of the hexagonal guiding ring 5 guides the input of the mud. The anti-drop connecting rod 21 is integrally installed inside the anti-drop joint 1 through the hoop cavity, and is assembled with the anti-drop joint 1 through the cooperation of the three-claw anti-disengagement pad 61, the anti-drop gasket 63, the right-threaded ring 64 and the left-threaded nut 65, and is clamped at the hoop opening inside the anti-drop joint 1.

[0048] During use, by changing the traditional disc-shaped anti-loosening gasket to a three-claw structure anti-loosening gasket, the flow area of the drilling fluid can be increased, preventing the problem of pump choking when the lower thread of the drill string breaks, reducing unpredictable secondary downhole accidents, and improving the safety and reliability of the positive displacement motor when in use. Also, by designing the traditional single anti-drop back nut, i.e., the left-handed back nut, into a double back nut joint form anti-drop back nut with left-handed and right-handed threads processed, and using the double reverse threads as the structural design to prevent thread loosening, the problem of the anti-drop back nut becoming unthreaded can be effectively avoided, increasing the safety factor.

[0049] And when the mud passes through the mud pump, flows through the bypass valve and the anti-drop joint 1 and enters the motor assembly 4, a certain pressure difference is formed at the inlet and outlet of the motor assembly 4, pushing the motor rotor to rotate, and transmitting the torque and speed to the drill bit through the universal shaft and the transmission shaft. During this use process, the anti-loosening ring frame 31 and the hexagonal guiding ring 5 are used as the limiting structures for the forward and backward movement of the anti-drop assembly 2 at the ferrule position. The front and back sliding movement of the ball 33 on the two spring rods 34 in the guiding rail cavity is used to cooperate with the anti-loosening ring frame 31 and the hexagonal guiding ring 5 to limit the anti-drop of the anti-drop assembly 2. While further enhancing the anti-drop performance of the anti-drop assembly 2 inside the anti-drop joint 1, it linearly guides the trajectory of the forward and backward movement of the anti-drop assembly 2 inside the anti-drop joint 1, so that the forward and backward movement trajectory always remains at the position corresponding to the left thread nut 65 and the hexagonal guiding ring 5. On the one hand, through the cooperation of the guiding rail cavity opened on the surface of the anti-drop connecting rod 21 and the ball cover ear 24 to guide and block the spring rod 34, the three-claw anti-loosening pad 61 will not directly collide with the ferrule inside the anti-drop joint 1 under normal working conditions, eliminating the hidden danger of the overall loosening of the double nut assembly 6. On the other hand, through the side filter holes 62 allowing the mud to pass through, and the joint blocking and backflow of the oncoming part of the mud by the anti-loosening ring frame 31 and the conical ring 32, the wall surface of the three-claw anti-loosening pad 61 adjacent to the ferrule will not easily collide together, further avoiding the triggering of the double nut assembly 6 when the anti-drop connecting rod 21 retracts inside the anti-drop joint 1.

[0050] Second embodiment, on the basis of the first embodiment, please refer to Figures 1 to 8 As shown, the universal shaft fixing assembly 7 includes a directional head 71. One end of the directional head 71 away from the anti-drop connecting rod 21 is fixedly connected with a sealing ring 76. Inside the sealing ring 76, a connecting piece 73 is installed, and a ball shaft sleeve 72 is assembled on the outer surface of the connecting piece 73 for rotatably clamping the surface of the connecting piece 73 with the inner wall of the sealing ring 76. At the end of the connecting piece 73 close to the directional head 71, a top ball joint 77 is fixedly installed, and the connecting piece 73 is hinged to the middle part inside the directional head 71 through the top ball joint 77.

[0051] A first sealing hopper cover 74 is fixedly sleeved on the outer surface of the connecting member 73. A sealing inner ring 75 is fixedly connected in a ring shape on the inner wall surface of the first sealing hopper cover 74. The sealing joint ring 76 is snap-fitted and installed on the first sealing hopper cover 74 through the sealing inner ring 75. Among them, the anti-falling connecting rod 21, the orientation head 71, and the motor assembly 4 are all installed in the hoop cavity of the anti-falling joint 1, and one end of the anti-falling connecting rod 21 away from the hexagonal guiding ring 5 is assembled with the orientation head 71 through the motor assembly 4.

[0052] During use, the first sealing hopper cover 74 and the sealing inner ring 75 can be jointly sleeved on the outer surface of the sealing joint ring 76. Through the overall tight sleeving of the first sealing hopper cover 74 on the outer surface of the sealing joint ring 76, and the tight clamping of the sealing inner ring 75 on the sealing joint ring 76 inside the first sealing hopper cover 74, double sealing between the connecting member 73 and the orientation head 71 is achieved. By the above method, the traditional universal shaft with spherical hinges at both ends is changed to a structure with a spherical hinge at only one end, and the original single-sealing sleeve of the spherical hinge is changed to a double-sealing sleeve, achieving the purpose of long-term sealing and enabling the universal shaft to have a longer service life.

[0053] Third embodiment, on the basis of the first and second embodiments, please refer to Figures 1 to 8 As shown, the adjustable universal shaft assembly 8 includes an adjustable joint body 81. Threaded joints 82 are fixedly connected to the middle parts of the front and rear ends of the adjustable joint body 81. A connecting thread 83 is provided at the inner wall where the anti-falling joint 1 is assembled with the adjustable joint body 81. The anti-falling joint 1 is threadedly connected to the adjustable joint body 81 through the cooperation of the connecting thread 83 and the threaded joint 82; a connecting thread 84 is provided at the inner wall where the transmission shaft tube 10 is assembled with the adjustable joint body 81. The transmission shaft tube 10 is threadedly connected to the adjustable joint body 81 through the cooperation of the connecting thread 84 and the threaded joint 82.

[0054] The cylindrical roller bearing assembly 9 includes a first steel ring 91. A second steel ring 92 is installed on the other side of the first steel ring 91. A middle ring body 95 is fixedly connected in the middle between the first steel ring 91 and the second steel ring 92. A plurality of rollers 93 and rectangular strips 94 are circularly arranged inside the middle ring body 95. The rollers 93 are located between the first steel ring 91 and the second steel ring 92 and are rotatably installed with the middle ring body 95. The rollers 93 and the rectangular strips 94 are alternately installed on the middle ring body 95, and the rectangular strips ⑨4 are fixedly installed with the middle ring body 95. Among them, the rollers 93 protrude from the inner and outer wall surfaces of the middle ring body 95 and are exposed outside the projection circular ring where the first steel ring 91 and the second steel ring 92 are located, and can be in close contact with the inner wall of the transmission shaft tube 10. The rectangular strips 94 protrude from the inner wall surface of the middle ring body 95 as a whole and are slightly lower than the thickness of the protrusion of the rollers 93 on the inner wall surface of the middle ring body 95.

[0055] During use, when the roller 93 located inside the middle ring body 95 is worn, in combination with the relative rotation between the first steel ring 91 and the second steel ring 92 and the inner wall of the transmission shaft tube 10, under the relative rotation action of the rectangular strip 94 inside the middle ring body 95, the worn roller 93 can be temporarily replaced for a short time to play a role, preventing the cylindrical roller bearing assembly 9 from being damaged or broken as a whole and blocking in the transmission shaft tube 10, providing a reaction time for timely discovery and replacement of the new cylindrical roller bearing assembly 9 and providing temporary protection for the inner structure of the transmission shaft tube 10.

[0056] By changing the external connection threads between the traditional assemblies from four to Figure 2 two threads in [reference], the probability of the threads being reversed and broken is reduced by half, removing the bypass valve assembly and the anti-drop joint threads, greatly reducing the risk coefficient of the external connection threads being reversed and broken, effectively reducing the risk of the downhole motor falling into the well due to thread reversal and breakage, and greatly improving the safety and stability coefficient of downhole operations.

[0057] Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art and related fields without creative efforts shall fall within the scope of protection of the present invention. The structures, devices, and operation methods not specifically described and explained in the present invention shall be implemented by conventional means in the art unless otherwise specified and limited.

Claims

1. A non-back-off screw drill for oil drilling operations, comprising a drop prevention joint (1), characterized in that: The inside of the anti-drop joint (1) is assembled with an anti-drop component (2). The inside of the anti-drop joint (1) is penetrated and provided with a hoop cavity and a hoop opening. A drive shaft tube (10) is installed at the tail end of the anti-drop joint (1). A motor assembly (4) is fixedly installed in the hoop cavity of the anti-drop joint (1). An anti-drop component (2) is assembled inside the anti-drop joint (1) and is used for conveying mud. The anti-drop component (2) includes an anti-drop connecting rod (21). Wide slots (22) and narrow slots (23) are symmetrically formed on the outer surface of the anti-drop connecting rod (21). A rounded step (25) is arranged between the wide slots (22) and the narrow slots (23). The wide slots (22) are communicated with the narrow slots (23) through the rounded step (25). Among them, the slot depth of the wide slots (22) is greater than that of the narrow slots (23), and the slot width of the wide slots (22) is greater than that of the narrow slots (23). A ball cover ear (24) is fixedly connected to the outer surface of the anti-drop connecting rod (21) and is arranged at one end far from the narrow slots (23). A short cover ear (26) is fixedly connected to the outer surface of the anti-drop connecting rod (21) and is arranged at one end far from the wide slots (22). The longitudinal extension length of the short cover ear (26) is less than that of the ball cover ear (24). Among them, the curved surface of the ball cover ear (24) faces the opposite direction of the mud input direction. The wide slots (22), the rounded step (25) and the narrow slots (23) together form a guide rail cavity. An anti-disengagement component (3) is assembled inside the anti-drop joint (1) and is arranged far from the near port of the anti-drop joint (1) and is used for intercepting the inward sliding of the anti-drop component (2) into the anti-drop joint (1). A double nut assembly (6) is installed on the anti-drop connecting rod (21) and at one end far from the anti-disengagement ring frame (31) and is used for limiting and blocking the front end of the anti-drop connecting rod (21) inside the anti-drop joint (1). A universal shaft fixing component (7) is assembled at the tail end of the anti-drop component (2) and is arranged in the hoop cavity of the anti-drop joint (1). An adjustable universal shaft assembly (8) is assembled between the anti-drop joint (1) and the drive shaft tube (10) and is used for assembling and connecting the anti-drop joint (1) and the drive shaft tube (10). A cylindrical roller bearing assembly (9) is installed inside the drive shaft tube (10).

2. The anti-unthreading screw drill tool for oil drilling operations according to claim 1, characterized in that: The anti - detachment component (3) includes an anti - detachment ring frame (31) fixedly installed inside the anti - dropping connector (1). One end of the anti - detachment ring frame (31) close to the spherical cover ear (24) is fixedly connected with a frustum ring (32). Two spring rods (34) are symmetrically installed at one end of the anti - detachment ring frame (31) close to the spherical cover ear (24), and are arranged at an inclination angle with respect to the plane where the axis of the anti - detachment ring frame (31) is located. The free end of each spring rod (34) is connected with a clamping ball (33), and the clamping ball (33) is telescopically installed with the anti - detachment ring frame (31) through the spring rod (34). The clamping ball (33) is fitted with the wide slot (22) through the spring rod (34) and can slide back and forth on the anti - dropping connecting rod (21) through the guiding rail cavity.

3. The anti-unthreading positive displacement motor for oil drilling operations according to claim 1, characterized in that: The double - nut assembly (6) includes a three - claw anti - detachment pad (61) sleeved on the front end of the anti - dropping connecting rod (21). The outer surface of the three - claw anti - detachment pad (61) is provided with side filter holes (62) at equal arc lengths, and the number is three. A anti - dropping gasket (63) is sleeved on the front end of the anti - dropping connecting rod (21). A right - hand threaded ring (64) is installed at the front end of the anti - dropping gasket (63) and is connected to the anti - dropping connecting rod (21) by a right - hand thread. A left - hand threaded cap (65) is installed at the front end of the right - hand threaded ring (64) and is connected to the anti - dropping connecting rod (21) by a left - hand thread. Among them, the outer diameters of the anti - dropping gasket (63), the right - hand threaded ring (64) and the left - hand threaded cap (65) are all equal and are larger than the inner diameter of the hoop opening, and the diameter of the three - claw anti - detachment pad (61) is larger than the outer diameter of the anti - dropping gasket (63).

4. A non-back-off positive displacement motor for oil drilling operations according to claim 1, characterized in that: A hexagonal guiding ring (5) is fixedly installed in the hoop cavity of the anti - dropping connector (1), and a hexagonal cavity is penetrated through the middle of the hexagonal guiding ring (5). The outer diameter of the anti - dropping gasket (63) is smaller than the diameter of the hexagonal cavity. The anti - dropping connecting rod (21) is integrally installed inside the anti - dropping connector (1) through the hoop cavity, and is assembled with the anti - dropping connector (1) through the cooperation of the three - claw anti - detachment pad (61), the anti - dropping gasket (63), the right - hand threaded ring (64) and the left - hand threaded cap (65), and is clamped at the hoop opening inside the anti - dropping connector (1).

5. A non-back-off screw drill for oil drilling operations according to claim 1, characterized in that: The universal - shaft fixing component (7) includes an orientation head (71). One end of the orientation head (71) far from the anti - dropping connecting rod (21) is fixedly connected with a sealing joint ring (76). A connecting piece (73) is installed inside the sealing joint ring (76), and a spherical shaft joint sleeve (72) is assembled on the outer surface of the connecting piece (73) for rotatably clamping the surface of the connecting piece (73) with the inner wall of the sealing joint ring (76).

6. The anti-unthreading screw drill tool for oil drilling operations according to claim 5, characterized in that: A top ball joint (77) is fixedly installed at the end of the connecting piece (73) close to the orientation head (71). The connecting piece (73) is hinged to the middle part inside the orientation head (71) through the top ball joint (77).

7. The anti-unthreading screw drill tool for oil drilling operations according to claim 6, characterized in that: A first sealing hopper cover (74) is fixedly sleeved on the outer surface of the connecting member (73), and a sealing inner ring (75) is fixedly connected in a ring shape on the inner wall surface of the first sealing hopper cover (74). The sealing joint ring (76) is snap-fitted and installed with the first sealing hopper cover (74) through the sealing inner ring (75). Among them, the anti-falling connecting rod (21), the orientation head (71) and the motor assembly (4) are all installed in the hoop cavity of the anti-falling joint (1), and one end of the anti-falling connecting rod (21) far from the hexagonal guiding ring (5) is assembled with the orientation head (71) through the motor assembly (4).

8. A non-back-off screw drill for oil drilling operations according to claim 1, characterized in that: The adjustable universal shaft assembly (8) includes an adjustable connector (81). Threaded joints (82) are fixedly connected to the middle parts of the front and rear ends of the adjustable connector (81). A first connecting thread (83) is provided at the inner wall where the anti-falling joint (1) is assembled with the adjustable connector (81). The anti-falling joint (1) is threadedly connected with the adjustable connector (81) through the cooperation of the first connecting thread (83) and the threaded joint (82).

9. The anti-unthreading screw drill tool for oil drilling operations according to claim 8, characterized in that: A second connecting thread (84) is provided at the inner wall where the transmission shaft tube (10) is assembled with the adjustable connector (81). The transmission shaft tube (10) is threadedly connected with the adjustable connector (81) through the cooperation of the second connecting thread (84) and the threaded joint (82).

10. The anti-unthreading screw drill tool for oil drilling operations according to claim 1, characterized in that: The cylindrical roller bearing assembly (9) includes a first steel ring (91). A second steel ring (92) is installed on the other side of the first steel ring (91). A middle ring body (95) is fixedly connected in the middle between the first steel ring (91) and the second steel ring (92). Roller (93) and rectangular strip (94) are circularly arrayed inside the middle ring body (95). The roller (93) is located between the first steel ring (91) and the second steel ring (92) and is rotatably installed with the middle ring body (95). The roller (93) and the rectangular strip (94) are staggeredly installed on the middle ring body (95), and the rectangular strip (94) is fixedly installed with the middle ring body (95). Among them, the roller (93) protrudes from the inner and outer wall surfaces of the middle ring body (95) and is exposed outside the projection circular ring where the first steel ring (91) and the second steel ring (92) are located, and can be closely attached to the inner wall of the transmission shaft tube (10). The whole rectangular strip (94) protrudes from the inner wall surface of the middle ring body (95) and is slightly lower than the thickness by which the roller (93) protrudes from the inner wall surface of the middle ring body (95).

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