Anti-falling device of screw drill

Abstract

The invention relates to the technical field of petroleum and natural gas extraction, in particular to an anti-falling device of a screw drill, and aims to solve the problem that when an existing anti-falling device is not shut down in time after a screw is broken, a motor rotor continuously rotates, so that a threaded connection is tripped, and a well falling accident is caused. The device comprises an anti-falling assembly, the anti-falling assembly is provided with a limiting body; when the motor rotor moves downwards, the limiting body is connected with the upper portion of the motor rotor in a clamped mode, the motor rotor is prevented from further falling, and when the lower portion of the screw drill is broken or tripped, the motor rotor slides downwards to drive the whole lower portion to move downwards. At the moment, the anti-falling blocking disc on the upper portion of the motor rotor can abut against the limiting boss, the motor rotor is prevented from sliding downwards continuously, and the possibility of well falling accidents is reduced. And meanwhile, after fracture occurs, an operator can easily take out the fractured part by lifting the tubular column, and a special fishing tool is not needed, so that the operation process is greatly simplified, and the working efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and in particular to an anti-drop device for screw drill bits. Background Technology

[0002] Screw drill strings, as an important downhole power tool in oil drilling, are widely used in directional and horizontal well drilling operations. Their core function is to improve drilling efficiency and accuracy through efficient power transmission and rotation. However, during downhole operations, screw drill strings are subjected to complex mechanical stresses, which can lead to breakage or thread stripping. If this occurs without a reliable anti-drop structure, the broken or stripped portion of the screw drill string may fall into the well, causing a serious drilling accident and resulting in significant economic losses.

[0003] A safe and reliable anti-drop structure is an indispensable component of screw drill strings and the last line of defense for ensuring smooth drilling operations. While traditional anti-drop devices can prevent accidents to some extent, their design still has some shortcomings. Especially in the event of a breakage or disengagement at the lower part of the screw, if the problem is not detected at the wellhead in time, the rotor will continue to rotate within the stator, causing the drill string to continue operating. In this situation, continuous rotation may cause the threads at the connection to disengage, ultimately losing its anti-drop function and increasing the risk of drilling accidents. Summary of the Invention

[0004] This invention provides an anti-fall device for screw drill bits to alleviate the problem of existing anti-fall devices causing the motor rotor to continuously rotate and the threaded connection to disengage, resulting in a fall into the well, when the screw breaks and the machine is not stopped in time.

[0005] To alleviate the above-mentioned technical problems, the technical solution provided by the present invention is as follows:

[0006] A screw drill bit anti-drop device, comprising an anti-drop assembly;

[0007] The anti-fall assembly has a limiting body;

[0008] When the motor rotor moves downward, the limiting body engages with the upper part of the motor rotor to prevent the motor rotor from falling further.

[0009] Furthermore,

[0010] The anti-fall assembly includes a limit boss and an anti-fall baffle;

[0011] The anti-drop plate is connected to the tie rod on the upper part of the motor rotor;

[0012] The pull rod is connected to the upper connector and the motor rotor from top to bottom;

[0013] The limiting boss is located at the lower part of the upper connector;

[0014] The anti-drop plate is located on the upper part of the limiting boss.

[0015] Furthermore,

[0016] The limiting boss gradually extends upward in the axial direction of the connector;

[0017] The center of the limiting boss has a cavity that runs vertically through it;

[0018] The inner diameter of the limiting boss is smaller than the outer diameter of the anti-drop plate.

[0019] Furthermore,

[0020] There is a gap between the inner wall of the limiting boss and the pull rod.

[0021] Furthermore,

[0022] The upper part of the anti-drop plate is fixedly connected to the pull rod by an anti-drop nut.

[0023] Furthermore,

[0024] The pull rod is fixedly connected to the motor rotor by a locking cap.

[0025] The beneficial effects of the anti-drop device for the screw drill bit in this invention are analyzed as follows:

[0026] If the existing anti-fall device fails to detect the breakage at the wellhead and stop the machine in time when the screw breaks, the motor rotor will continue to rotate, which will cause the threads at the connection to disengage, making the anti-fall device lose its anti-fall capability and causing a fall-in-well accident.

[0027] This device is designed to alleviate the above-mentioned problem by providing an anti-fall device. The device includes an anti-fall assembly with a limiting body. When the motor rotor moves downward, the limiting body engages with the upper part of the motor rotor to prevent the motor rotor from falling further.

[0028] When the motor rotor moves downwards, the limiting body engages with the upper part of the motor rotor, effectively preventing the motor rotor from falling further. Specifically, when the lower part of the screw drill string breaks or disengages, the motor rotor will slide downwards, causing the entire lower part to move downwards. At this time, the anti-falling baffle on the upper part of the motor rotor can abut against the limiting boss, preventing the motor rotor from continuing to slide downwards and reducing the possibility of a fall into the well. Furthermore, after a breakage occurs, operators can easily retrieve the broken part by lifting the tubing string without the need for special retrieval tools, greatly simplifying the operation process and improving work efficiency. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of the present invention, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 A schematic diagram of the anti-drop device for screw drill provided in an embodiment of the present invention.

[0031] icon:

[0032] 100 - Anti-drop assembly; 110 - Limiting boss; 120 - Anti-drop retaining plate; 130 - Anti-drop nut;

[0033] 200 - Motor rotor; 210 - Tie rod;

[0034] 300-Top connector;

[0035] 400-Lock-in back cap. Detailed Implementation

[0036] A safe and reliable anti-drop structure is an indispensable component of screw drill strings and the last line of defense for ensuring smooth drilling operations. While traditional anti-drop devices can prevent accidents to some extent, their design still has some shortcomings. Especially in the event of a breakage or disengagement at the lower part of the screw, if the problem is not detected at the wellhead in time, the rotor will continue to rotate within the stator, causing the drill string to continue operating. In this situation, continuous rotation may cause the threads at the connection to disengage, ultimately losing its anti-drop function and increasing the risk of drilling accidents.

[0037] In view of this, such as Figure 1 As shown, this solution provides an anti-drop device for screw drills to alleviate the above-mentioned problems.

[0038] This device includes an anti-drop assembly 100;

[0039] The anti-fall assembly 100 has a limiting body;

[0040] When the motor rotor 200 moves downward, the limiting body engages with the upper part of the motor rotor 200 to prevent the motor rotor 200 from falling further.

[0041] Specifically, when the lower part of the screw drill string breaks or detaches, the motor rotor 200 will slide downwards, causing the lower part of the screw to move downwards as a whole. The upper part of the motor rotor 200 is equipped with a locking block that cooperates with the limiting body, which can lock the motor rotor 200 to prevent it from falling continuously and causing a well fall accident. Furthermore, after the upper part of the motor rotor 200 is locked with the limiting body, the broken part can be removed from the well by lifting the tubing string, which is convenient for operators to maintain and repair the equipment.

[0042] In this solution, the shape and structure of the anti-drop assembly 100 are as follows: Figure 1 As shown:

[0043] The anti-drop assembly 100 includes a limiting boss 110 and an anti-drop baffle 120;

[0044] The anti-drop plate 120 is sleeved with the tie rod 210 on the upper part of the motor rotor 200;

[0045] The pull rod 210 is inserted into the upper connector 300 and the motor rotor 200 from top to bottom;

[0046] The limiting boss 110 is located at the lower part of the upper connector 300;

[0047] The anti-drop plate 120 is located on the upper part of the limiting boss 110;

[0048] The limiting boss 110 gradually extends upward in the axial direction of the connector 300;

[0049] The center of the limiting boss 110 has a cavity that runs vertically through it;

[0050] The inner diameter of the limiting boss 110 is smaller than the outer diameter of the anti-drop plate 120;

[0051] There is a gap between the inner wall of the limiting boss 110 and the pull rod 210.

[0052] Specifically, the breakage and disengagement points of the screw drill bit are located on the upper part of the anti-drop assembly 100. When the screw drill bit breaks or disengages, the connection between the pull rod 210 and the upper part will separate, causing the motor rotor 200 to move downwards. An anti-drop baffle 120 extending horizontally is provided on the upper part of the pull rod 210, so that the outer diameter of the anti-drop baffle 120 is larger than the inner diameter of the limiting boss 110. When the motor rotor 200 moves downwards, the lower surface of the anti-drop baffle 120 abuts against the upper surface of the limiting boss 110, so that the downward movement of the motor rotor 200 is limited within a reasonable range, avoiding secondary accidents. Furthermore, after breakage or disengagement, the broken part can be removed by lifting the pipe string without the need for special retrieval tools, simplifying the operation process and improving the work efficiency of the operators.

[0053] In this design, the upper part of the anti-drop plate 120 is fixedly connected to the pull rod 210 via the anti-drop nut 130 to facilitate the installation and maintenance of the equipment. Preferably, a shaft retaining ring can also be installed between the anti-drop nut 130 and the pull rod 210 to prevent the anti-drop nut 130 from coming loose and causing connection failure.

[0054] In this design, the pull rod 210 is fixedly connected to the motor rotor 200 by a locking cap 400 to prevent the pull rod 210 from failing due to thread unraveling during the continuous rotation of the motor rotor 200 after breakage.

[0055] This solution has at least the following beneficial effects:

[0056] While traditional anti-drop devices can prevent equipment from accidentally falling to some extent, they still have some significant shortcomings in practical applications. For example, if the lower part of the screw breaks or disengages, and the problem is not detected at the wellhead in time, the motor rotor may continue to rotate inside the stator. In this case, continuous rotation can cause the threads at the connection to disengage, thus losing the anti-drop function and increasing the risk of drilling accidents.

[0057] To address these issues, this solution incorporates an anti-fall device. When the motor rotor descends, a limiting body engages with the upper part of the motor rotor, effectively preventing further descent. Specifically, when the lower part of the screw drill string breaks or disengages, the motor rotor slides downwards, causing the entire lower part to descend. At this point, the anti-fall baffle 120 on the upper part of the motor rotor abuts against the limiting boss 110, preventing the motor rotor from continuing to slide downwards and reducing the likelihood of a fall-in-the-well accident. Furthermore, in the event of a breakage, operators can easily retrieve the broken portion by lifting the tubing string without the need for special retrieval tools, significantly simplifying the operation and improving work efficiency.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for preventing the screw drill bit from falling off, characterized in that: Including the anti-fall assembly (100); The anti-fall assembly (100) has a limiting body; When the motor rotor (200) moves downward, the limiting body engages with the upper part of the motor rotor (200) to prevent the motor rotor (200) from falling further.

2. The anti-drop device for the screw drill bit according to claim 1, characterized in that: The anti-drop assembly (100) includes a limiting boss (110) and an anti-drop baffle (120); The anti-drop plate (120) is sleeved with the pull rod (210) on the upper part of the motor rotor (200); The pull rod (210) is connected to the upper connector (300) and the motor rotor (200) from top to bottom; A limiting boss (110) is provided at the lower part of the upper connector (300); The anti-drop plate (120) is disposed on the upper part of the limiting boss (110).

3. The anti-drop device for the screw drill bit according to claim 2, characterized in that: The limiting boss (110) gradually extends in the axial direction of the upper connector (300); The center of the limiting boss (110) has a cavity that runs vertically through it. The inner diameter of the limiting boss (110) is smaller than the outer diameter of the anti-drop plate (120).

4. The anti-drop device for the screw drill bit according to claim 3, characterized in that: There is a gap between the inner wall of the limiting boss (110) and the pull rod (210).

5. The anti-drop device for the screw drill bit according to claim 4, characterized in that: The upper part of the anti-drop plate (120) is fixedly connected to the pull rod (210) by the anti-drop nut (130).

6. The anti-drop device for the screw drill bit according to claim 5, characterized in that: The pull rod (210) and the motor rotor (200) are fixedly connected by a locking cap (400).

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