Wellhead blowout-prevention and anti-theft device capable of preventing screwing and unscrewing

Abstract

The utility model relates to the technical field of oil well blowout prevention and theft prevention equipment, in particular to an anti-rotation well mouth blowout prevention and theft prevention device, and provides the anti-rotation well mouth blowout prevention and theft prevention device aiming at the problems that an anti-theft mechanism of a conventional well mouth blowout prevention and theft prevention device in the industry is prone to failure, and pressure relief and oil bailing operation is inconvenient. On the basis of a sealing pressure relief body and a password cap structure, an adjusting rod, an anti-theft ring, an anti-loosening ring and a sealing core block are additionally arranged to limit a sliding rod to be separated from a bottom sleeve. The anti-theft ring is matched with the password cap locking block, so that unlocking caused by swinging and rotating the password cap is avoided; the anti-loosening ring enhances the matching tightness of the parts and reduces shaking; the adjusting rod achieves the dual functions of sealing the wellhead and separating the bottom sleeve, special tools are not needed, and the top anti-theft screw hole strengthens theft prevention. The design that the sealing core block limits the sliding rod to be separated from the bottom sleeve realizes quick separation of the sealing seat and the bottom sleeve, and wellhead threads are prevented from being disassembled during oil bailing operation. The device effectively improves the anti-theft capability, and enhances the convenience of pressure relief and oil bailing.

Description

Technical Field

[0001] The utility model relates to the technical field of oil well blowout prevention and theft prevention equipment, in particular to an anti-rotation wellhead blowout prevention and theft prevention device. Background Art

[0002] In oilfield production and operations, the periodic shutdown and dynamic resumption of oil well production are routine operational requirements. When a well enters the shutdown phase, mechanical locking and password verification mechanisms are used to prevent theft of crude oil and malicious damage to equipment.

[0003] At present, although the conventional wellhead blowout prevention and anti-theft devices in the industry have achieved basic anti-theft functions, they have exposed obvious technical shortcomings in complex working environments. On the one hand, in some special operating scenarios, there are gaps in the structural design of the device. Criminals can take advantage of this defect and implement targeted technical unlocking operations by rotating and shaking the password cap at high frequencies and coordinating with the gradual rotation of the single locking rod, causing the anti-theft mechanism to fail, thereby causing crude oil theft cases and the risk of wellhead loss of control. On the other hand, the pressure relief operation of traditional devices relies on additional special tools, and during the oil recovery operation, it is impossible to accurately control the pressure relief flow rate in real time, which greatly prolongs the operation preparation time and reduces the operation efficiency.

[0004] Currently, conventional oil recovery operations for wellhead blowout and theft prevention devices in the industry begin by unlocking and depressurizing the device. Once the internal pressure is released, specialized tools are used to remove the device from the wellhead casing, opening the wellhead structure and ultimately recovering the residual oil under normal pressure. Due to the frequent removal of the device from the wellhead casing, scratches and gouges gradually form on the threads of the device and the casing, directly degrading the sealing performance of the threaded engagement. Utility Model Content

[0005] The purpose of the utility model is to provide an anti-rotation wellhead blowout and anti-theft device, which adds an adjusting rod, an anti-theft ring, an anti-loosening ring and a sealing core block limiting sliding rod to separate from the bottom sleeve design, so as to solve the problem of improving the anti-theft ability and the convenience of pressure relief and oil recovery in the above-mentioned background technology.

[0006] The technical solution of the utility model is as follows:

[0007] The utility model discloses an anti-rotation and anti-blowout and anti-theft device for a wellhead, comprising: a sealing pressure relief body, a password cap and an anti-theft ring. The bottom sleeve of the sealing pressure relief body is installed at the wellhead, the annular groove of the sealing seat of the sealing pressure relief body is sleeved with the anti-theft ring, the adjusting rod is threaded and inserted into the upper part of the sealing seat, and the locking block of the password cap locks the anti-theft ring, so that the password cap rotates on the sealing pressure relief body, thereby preventing unlocking caused by swinging and rotating the password cap.

[0008] The password cap includes a lock cap, a lock rod, a lock block and an anti-loosening ring;

[0009] The sealing pressure relief body includes a sealing seat, a bottom sleeve, a core seat, a sealing core block, a retaining ring, a sliding rod, an adjusting rod, and an O-ring;

[0010] A quick-install flange is designed on one side of the upper portion of the sealing seat, and an O-ring 1 and an O-ring 2 are inserted into the outer ring groove of the lower portion of the sealing seat;

[0011] The top of the adjusting rod is designed with an anti-theft screw hole, and the adjusting rod needs to be rotated using a matching special key socket wrench. The special key socket wrench includes an L-shaped long handle and a raised password block adapted to the anti-theft screw hole, which are connected by a square buckle interlocking mechanism;

[0012] The anti-theft ring is formed by welding the half rings after the A half ring and the B half ring are respectively inserted into the annular groove of the sealing seat. The anti-theft ring forms a freely rotatable dynamic ring in the annular groove of the sealing seat. The locking grooves of the locking block and the anti-theft ring lock and unlock with each other. The notches of the four locking blocks point to the central axis of rotation of the anti-theft ring to achieve unlocking. The anti-theft ring enables the password cap to rotate and lock on the sealing pressure relief body.

[0013] The utility model has the following beneficial effects:

[0014] In order to solve the hidden danger of password leakage in conventional designs, that is, when the anti-theft ring and anti-loosening ring are not installed, the password cap will warp when the password cap is shaken up and down and rotated, and a locking rod is adjusted to the password unlocking position. This may cause the password cap to warp, which may lead to password leakage. The anti-theft ring and anti-loosening ring design introduced in this utility model effectively solves this problem. The anti-loosening ring enhances the tightness of the upper and lower fit between the lock block, the lock cap and the anti-theft ring, greatly reducing the amplitude of the up and down shaking; the anti-theft ring can rotate along the annular groove of the sealing seat and is tightly locked with the lock block. When encountering technical cracking, the password cap will not warp when rotating on the sealing pressure relief body, which fundamentally avoids password leakage.

[0015] The spiral adjustment rod design gives the seal pressure relief body the dual function of separating the wellhead seal from the bottom casing, simplifying the overall structure and eliminating the need for additional tools to assist in pressure relief. This creates a dual anti-theft structure for the entire device. Rotation of the adjustment rod drives the seal core block up and down, and combined with the guiding action of the limit slide bar, this design eliminates the need for threaded disassembly of the wellhead casing, effectively preventing scratches and dents on the threaded surfaces of the device and casing caused by frequent disassembly and assembly. This simplifies pre-recovery operations, improves oil recovery efficiency, and ensures long-term sealing stability during sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a structural diagram of the anti-rotation wellhead blowout and anti-theft device;

[0017] Figure 2 A cross-sectional view of the circumferential array of through holes of the sealing pressure relief body;

[0018] Figure 3 Schematic diagram of the password cap structure;

[0019] Figure 4 Schematic diagram of the structure of the anti-theft ring;

[0020] In the accompanying drawings shown, 1. Lock cap; 2. Lock rod; 3. Lock block; 4. Sealing seat; 4.1. Quick-release flange; 4.2. O-ring one; 4.3. O-ring two; 4.4. O-ring three; 5. Bottom sleeve; 6. Core seat; 7. Sealing core block; 8. Retaining ring; 9. Sliding rod; 9.1. Spring; 10. Adjusting rod; 10.1. Anti-theft screw hole; 11. Anti-loosening ring; 12. O-ring four; 13. Anti-theft ring; 13.1. Half ring A; 13.2. Half ring B; 13.3. Lock groove. DETAILED DESCRIPTION

[0021] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0023] In the description of this utility model, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.

[0024] Example

[0025] The present invention is further described in detail below with reference to the accompanying drawings:

[0026] like Figure 1-3As shown, an anti-rotation and anti-blowout and anti-theft device for a wellhead includes: a sealing pressure relief body, a password cap, and an anti-theft ring 13. The bottom sleeve 5 of the sealing pressure relief body is installed at the wellhead, and the annular groove of the sealing seat 4 of the sealing pressure relief body is covered with the anti-theft ring 13. The adjusting rod 10 is threaded and rotated to be inserted into the upper part of the sealing seat 4. The locking block 3 of the password cap locks the anti-theft ring 13, so that the password cap can rotate on the sealing pressure relief body, thereby preventing unlocking caused by swinging and rotating the password cap.

[0027] like Figure 3 The password cap includes a lock cap 1, a lock rod 2, a lock block 3 and an anti-loosening ring 11. The anti-loosening ring 11 is inserted into the lock rod 2, and the lock rod 2 is inserted into the through hole of the lock cap 1. The lock block 3 is welded to the lower end of the lock rod 2.

[0028] like Figure 1 and Figure 2 As shown, the sealing pressure relief body includes a sealing seat 4, a bottom sleeve 5, a core seat 6, a sealing core block 7, a retaining ring 8, a sliding rod 9, an adjusting rod 10, an O-ring 4 12, and an anti-theft ring 13. The O-ring 3 4.4 and the core seat 6 are inserted into the bottom of the inner hole of the sealing seat 4, and the retaining ring 8 is installed to screw the core seat 6. The lower part of the inner hole of the sealing seat 4 is provided with 4-8 circumferential array through holes, and the sliding rod 9 is installed in the array through holes, and the sliding rod 9 is sleeved with a spring 9.1. The adjusting rod 10 is sealed with the O-ring 4 12 in the upper groove of the sealing seat 4. The lower part of the adjusting rod 10 is connected to the sealing core block 7. The lower conical surface of the sealing core block 7 presses the core seat 6 to seal. The upper part of the sealing core block 7 blocks the sliding rod 9, pressing The spring 9.1 is compressed, and the outer hemisphere of the slide rod 9 is inserted into the hemispherical groove of the bottom sleeve 5 to realize the connection between the sealing seat 4 and the bottom sleeve 5. The adjusting rod 10 is rotated to drive the sealing core block 7 to lift up, and the spring 9.1 rebounds. The middle part of the sealing core block 7 blocks the slide rod 9. The spring 9.1 pushes the outer hemisphere of the slide rod 9 to disengage from the hemispherical groove of the bottom sleeve 5, and the sealing seat 4 is lifted up, completing the separation of the sealing seat 4 and the bottom sleeve 5. The bottom sleeve 5 remains in the wellhead casing. The sealing core block 7 limits the slide rod 9 to disengage from the bottom sleeve 5 structure, avoiding the disassembly of the wellhead thread during the oil recovery operation;

[0029] The upper side of the sealing seat 4 is provided with a quick-install flange 4.1, and the outer ring groove at the lower part of the sealing seat 4 is inserted with an O-ring 1 4.2 and an O-ring 2 4.3;

[0030] The top of the adjusting rod 10 is designed with an anti-theft screw hole 10.1, and the adjusting rod 10 needs to be rotated using a matching special key socket wrench. The special key socket wrench includes an L-shaped long handle and a raised password block adapted to the anti-theft screw hole 10.1, which is connected by a square buckle interlocking mechanism;

[0031] like Figure 1 and Figure 4As shown, the anti-theft ring 13 adopts a split structure, and the A half ring 13.1 and the B half ring 13.2 are respectively embedded in the annular groove of the sealing seat 4 and then welded to form a freely rotatable dynamic ring. The upper part of the anti-theft ring 13 is a small circular ring of a precisely adapted retaining ring, and the middle part is expanded to a large circular ring that carries the core locking function. The outer ring of the large circular ring is milled with four semi-runway-shaped lock grooves 13.3 in a circumferentially symmetrical and evenly distributed manner. The matching lock block 3 adopts an arc-shaped notch on the inside and a semicircular protrusion on the outside. The diameter of the inner notch of the lock block 3 is 0.15mm±0.05mm larger than the diameter of the small circular ring of the retaining ring of the anti-theft ring 13, and the outer arc diameter of the lock block 3 is 0.15mm±0.05mm smaller than the diameter of the circular groove 13.3. The lock block 3 is rotated to lock and unlock with the lock groove 13.3 of the anti-theft ring 13;

[0032] Rotate the pointers of the four locking rods 2 to the unlocking password position. At this time, the gaps of the four lock blocks 3 will point to the rotation center axis of the anti-theft ring 13. Lift the password cap to complete the unlocking.

[0033] The anti-theft screw hole 10.1 is in a zigzag shape, a plum blossom shape, or an inner pentagonal shape.

[0034] How it works:

[0035] During the well sealing operation, the sealing pressure relief body is installed on the casing coupling at the wellhead through the bottom sleeve 5. At this time, the sealing pressure relief body seat is sealed at the wellhead, the sealing core block 7 and the core seat 6 form a sealing pair, the O-ring 1 4.2 and the O-ring 2 4.3 seal the gap between the sealing seat 4 and the bottom sleeve 5, and the O-ring 3 4.4 seals the gap between the sealing seat 4 and the core seat 6. The well fluid and gas in the well are sealed in the well, and the sealing and blowout prevention are reliably achieved. The password cap is installed. A groove is provided on the top of the locking rod 2. The locking rod 2 can be rotated with a flat-blade screwdriver or other tools. By rotating the locking rod 2, the pointers of the four locking rods 2 are rotated to the preset password position, so that the locking block 3 is aligned with the lock groove 13.3 of the anti-theft ring 13, thereby realizing the locking and unlocking of the sealing pressure relief body and the password cap.

[0036] During the oil recovery operation, after the rotating lock rod 2 is unlocked, the password cap is removed, and the quick-fit flange 4.1 is quickly sealed and connected to the flange of the external pipeline through the live clamp. A special key socket wrench is inserted into the anti-theft screw hole 10.1 on the top of the adjusting rod 10, and the special key socket wrench is rotated. At this time, the adjusting rod 10 moves upward after the thread is rotated, and the sealing core block 7 is lifted up to separate from the core seat 6. The liquid and gas in the well flow upward through the quick-fit flange 4.1 into the pipeline for recovery. After the oil well is depressurized to normal pressure, the adjusting rod 10 continues to rotate and move upward. At this time, the spring 9.1 rebounds, and the middle part of the sealing core block 7 blocks the sliding rod 9. The spring 9.1 pushes the outer end hemisphere of the sliding rod 9 to separate from the hemispherical groove of the bottom sleeve 5, and the sealing seat 4 is lifted, completing the separation of the sealing seat 4 and the bottom sleeve 5. The bottom sleeve 5 remains in the wellhead casing, forming a wellhead size sufficient for oil recovery operation, and the oil recovery operation begins.

[0037] When resuming the operation, remove the pipeline on the quick-release flange 4.1, rotate the special key socket wrench in the opposite direction, move the adjusting rod 10 downward, and the lower conical surface of the sealing core block 7 presses the core seat 6 for sealing. At this time, the upper part of the sealing core block 7 blocks the slide rod 9, compresses the spring 9.1, and the outer hemisphere of the slide rod 9 is inserted into the hemisphere groove of the bottom sleeve 5. The sealing seat 4 and the bottom sleeve 5 are reconnected to complete the sealing of the pressure relief body seat and seal the wellhead. After installing the password cap, rotate the locking rod 2 to lock it.

[0038] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and exemplary embodiments. They can be applied to a variety of fields suitable for the present invention. Further modifications will be readily apparent to those skilled in the art. Therefore, the present invention is not limited to the specific details and illustrations shown and described herein without departing from the general concept defined by the claims and their equivalents.

Claims

1. An anti-rotation wellhead blowout and anti-theft device, characterized in that: include: A sealing pressure relief body, a password cap and an anti-theft ring (13), wherein the bottom sleeve (5) of the sealing pressure relief body is installed at the wellhead, the annular groove of the sealing seat (4) of the sealing pressure relief body is sleeved with the anti-theft ring (13), the adjusting rod (10) is threadedly rotated and inserted into the upper part of the sealing seat (4), and the locking block (3) of the password cap locks the anti-theft ring (13), so that the password cap can rotate on the sealing pressure relief body, thereby avoiding unlocking caused by swinging and rotating the password cap; The top of the adjusting rod (10) is designed with an anti-theft screw hole (10.1), and a matching special key socket wrench is required to rotate the adjusting rod (10); The adjusting rod (10) is rotated to drive the sealing core block (7) to be lifted, the spring (9.1) rebounds, the middle of the sealing core block (7) blocks the slide rod (9), the spring (9.1) pushes the outer end hemisphere of the slide rod (9) to be separated from the hemisphere groove of the bottom sleeve (5), and the sealing seat (4) is lifted, so that the sealing seat (4) and the bottom sleeve (5) are separated, and the bottom sleeve (5) remains in the wellhead casing, avoiding the wellhead thread from being disassembled during the oil recovery operation; The anti-theft ring (13) adopts a split structure, wherein the A half ring (13.1) and the B half ring (13.2) are respectively embedded in the annular groove of the sealing seat (4) and then welded to form a freely rotatable dynamic ring.

2. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The upper part of the anti-theft ring (13) is a small ring of a precisely adapted retaining ring, and the middle part is expanded into a large ring that carries the core locking function. The outer ring of the large ring is milled with four semi-runway-shaped lock grooves (13.3) in a circumferentially symmetrical and evenly distributed manner. The lock block (3) matched therewith adopts an arc-shaped notch on the inner side and a semicircular protrusion on the outer side.

3. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The diameter of the inner notch of the locking block (3) is 0.15 mm ± 0.05 mm larger than the diameter of the small circular ring of the anti-theft ring (13), and the diameter of the outer arc of the locking block (3) is 0.15 mm ± 0.05 mm smaller than the diameter of the circular groove of the locking groove (13.3). The locking block (3) is rotated to lock and unlock with the locking groove (13.3) of the anti-theft ring (13).

4. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The sealing pressure relief body comprises: a sealing seat (4), wherein the bottom of the inner hole of the sealing seat (4) is inserted with an O-ring three (4.4) and a core seat (6), a retaining ring (8) is installed to thread-lock the core seat (6), 4-8 circumferential array through holes are provided in the lower middle part of the inner hole of the sealing seat (4), a slide rod (9) is installed in the array through holes, and a spring (9.1) is sleeved on the slide rod (9), and the adjusting rod (10) is sealed with the O-ring four (12) in the groove on the upper part of the sealing seat (4).

5. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The lower part of the regulating rod (10) is connected to the sealing core block (7), the lower conical surface of the sealing core block (7) presses the core seat (6) to seal, the upper part of the sealing core block (7) blocks the slide rod (9), compresses the spring (9.1), and the outer end hemisphere of the slide rod (9) is inserted into the hemisphere groove of the bottom sleeve (5), thereby realizing the connection between the sealing seat (4) and the bottom sleeve (5).

6. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The password cap comprises an anti-loosening ring (11), the anti-loosening ring (11) is inserted into the locking rod (2), the locking rod (2) is inserted into the through hole of the lock cap (1), and a locking block (3) is welded and installed on the lower end of the locking rod (2).

7. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The anti-theft screw hole (10.1) is in a zigzag shape, a plum blossom shape, or an inner pentagonal shape.

8. The anti-rotation wellhead blowout and anti-theft device according to claim 1, characterized in that: The special key socket wrench comprises an L-shaped long handle and a raised password block adapted to the anti-theft screw hole (10.1), which are connected via a square buckle interlocking mechanism.

9. The anti-rotation wellhead blowout and anti-theft device according to claim 6, characterized in that: Rotate the pointers of the four locking rods (2) to the unlocking password position. At this time, the gaps of the four locking blocks (3) will point to the rotation center axis of the anti-theft ring (13). Lift the password cap to complete the unlocking.

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