Well washing casing pipe sealing device

Abstract

The invention belongs to the technical field of in-situ leaching uranium mining, and particularly relates to a well washing sleeve sealing device. According to the device, through the single step of rotating the push rod, the radial expansion sealing of the rubber sleeve and the switching of the valve element flow channel can be synchronously completed, the sealing function and the flow channel control function are integrated into the single device, the operation process is simplified, and the operation efficiency is improved. The rubber sleeve generates radial expansion under axial extrusion and can be tightly attached to the irregular well wall, elastic sealing is formed, and adaptability is high. The bearing assembly ensures smooth rotation of the push rod, friction is reduced, and sealing failure caused by torsion stress is avoided. The valve element adopts the double-channel design of a lateral hole and a bottom hole, accurate alignment or closing is achieved through driving of the push rod, it is ensured that well washing media are rapidly converted into lateral circulation after sealing is established, well bottom blockage is avoided, and the well washing effect is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of in-situ leaching uranium mining, and particularly relates to a well washing casing sealing device. BACKGROUND

[0002] In the production process of in-situ leaching uranium mine, the problem of drilling hole blockage often occurs, which reduces the pumping and injection capacity. To solve this problem, well washing operations such as compressed air well washing, chemical well washing, and piston well washing are usually required. At present, with the deepening of drilling depth (more than 600 m) and the increase of pressure bearing (300-500 m), the pressure required for well washing operation is also increasing. In the related technology, the maximum pressure of well washing operation reaches more than 5.0 MPa. In the well washing operation, part of the wellhead device is damaged. Therefore, how to reduce the damage of well washing operation pressure to the wellhead device becomes a problem to be solved. SUMMARY

[0003] In order to overcome the problems in the related art, a well washing casing sealing device is provided, which comprises an upper joint, a bearing assembly, a rubber sleeve, a push rod sleeve, a push rod seat, a valve core sleeve and a lower joint arranged in sequence from top to bottom.

[0004] The upper end of the upper joint is used for connecting the well washing casing, and the lower end of the upper joint is fixedly connected with the upper end of the push rod. The bearing assembly is installed outside the push rod, and the upper joint does not directly contact the bearing assembly. The push rod sleeve, the push rod seat and the valve core sleeve are fixedly connected in sequence from top to bottom to form a tubular structure. The push rod is located in the tubular structure, and the rubber sleeve is sleeved and limited on the outside of the push rod between the bearing assembly and the push rod sleeve.

[0005] The lower section of the push rod is provided with an external thread which is matched with an internal thread in the inside of the push rod seat. The lower end of the push rod is connected with the upper end of the valve core through a spherical snap pin. When the push rod is rotated, the valve core can be driven to move axially along the tubular structure, and the valve core does not rotate with the push rod.

[0006] The valve core is slidably accommodated in a cavity composed of the valve core sleeve and the lower joint. The side wall and the lower end of the valve core are respectively provided with a lateral hole and a bottom hole for fluid flow. The side wall of the valve core sleeve is correspondingly provided with a through hole which can communicate with the lateral hole.

[0007] When the push rod is in the initial upper position, the rubber sleeve is in a natural state, the lateral hole of the valve core is closed, and the bottom hole is opened, and the fluid flows through the bottom passage. When the push rod is rotated downward to the bottom, the bearing assembly and the push rod sleeve extrude the rubber sleeve to make it radially expand to seal the drilling hole, and at the same time, the valve core moves downward to make the lateral hole of the valve core align with the through hole of the valve core sleeve, and the bottom hole is closed, so that the fluid flows through the lateral passage.

[0008] In a possible implementation, the lower end of the upper joint is connected to the upper end of the push rod by threads.

[0009] In a possible implementation, the bearing assembly and the push rod sleeve limit the rubber sleeve in a clamping manner or a boss structure.

[0010] In a possible implementation, the external threads of the lower section of the push rod are long thread sections to accommodate the long axial movement of the push rod during rotation.

[0011] In a possible implementation, the lateral holes of the valve core are multiple and uniformly distributed in the circumferential direction; and the valve core sleeve has a corresponding same number of through holes.

[0012] In a possible implementation, the bottom holes of the valve core are multiple and uniformly distributed in the circumferential direction.

[0013] In a possible implementation, the lower joint simultaneously serves as a valve core seat for limiting the downward end point of the valve core.

[0014] The device of the present disclosure has the advantages that the device of the present disclosure can simultaneously complete the radial expansion sealing of the rubber sleeve and the switching of the flow passage of the valve core through a single step of rotating the push rod, integrates the sealing and flow passage control functions in a single device, simplifies the operation process, and improves the work efficiency.

[0015] The rubber sleeve is radially expanded under axial extrusion, can closely fit the irregular well wall, forms an elastic seal, and has strong adaptability; the bearing assembly ensures smooth rotation of the push rod, reduces friction, and avoids failure of the seal due to torsional stress.

[0016] The valve core adopts a dual-channel design of lateral holes and bottom holes, realizes precise alignment or closure through push rod driving, ensures rapid lateral circulation of the well flushing medium after the seal is established, avoids well bottom blockage, and improves well flushing effect.

[0017] The components are sequentially connected, the internal push rod-valve core adopts a spherical pin joint to realize axial movement and non-rotating transmission, the overall structure is stable and compact, and the complexity of field installation and operation is reduced.

[0018] The key moving parts are protected by the sleeve, the rubber sleeve is replaceable, the threads and the limiting structure are reliable, the service life of the device in a high-pressure and multi-impurity environment is prolonged, and the maintenance frequency is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a schematic view of a well flushing sleeve sealing device in an assembled state according to an embodiment of the present disclosure.

[0020] Figure 2 is an exploded view of a wellbore casing sealing device according to an embodiment of the present disclosure.

[0021] Figure 3 is a use state diagram of a wellbore casing sealing device according to an embodiment of the present disclosure.

[0022] In the diagram:

[0023] 1. upper joint; 2. bearing & bearing seat; 3. rubber sleeve; 4. push rod sleeve; 5. push rod seat; 6. valve core sleeve; 7. lower joint; 8. push rod; 9. ball pin; 10. valve core; 11. wellbore casing sealing device; 12. liquid level.

[0024] 1. upper joint; 2. bearing & bearing seat; 3. rubber sleeve; 4. push rod sleeve; 5. push rod seat; 6. valve core sleeve; 7. lower joint; 8. push rod; 9. ball pin; 10. valve core; 11. wellbore casing sealing device; 12. liquid level.

[0025] 13. filter. DETAILED DESCRIPTION

[0026] The present disclosure will be described in further detail below with reference to the drawings and specific embodiments.

[0027] Unless otherwise defined, technical and scientific terms used in the present disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs; the terminology used in the disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure; the term "comprising" and any variation thereof, used in the disclosure is intended to cover not excluding; it is apparent that the embodiments described in the disclosure are only a part of the embodiments of the disclosure, not all the embodiments. Based on the embodiments in the disclosure, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the disclosure.

[0028] Reference to "embodiments" in the present disclosure means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of the present disclosure. The appearance of this phrase in various places in the specification does not necessarily all refer to the same embodiment, nor is it necessarily mutually exclusive of other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0029] Referring to Figure 1 and Figure 2 , the wellbore casing sealing device of the present disclosure comprises, from top to bottom, an upper joint 1, a bearing assembly 2, a rubber sleeve 3, a push rod sleeve 4, a push rod seat 5, a valve core sleeve 6 and a lower joint 7.

[0030] The upper joint 1 is used for connecting the well washing casing, the lower end of the upper joint 1 is threadedly connected with the upper end of the push rod 8; the bearing assembly 2 is installed outside the push rod 8, and the upper joint 1 is not in direct contact with the bearing assembly 2; the push rod sleeve 4, the push rod seat 5 and the valve core sleeve 6 are sequentially fixed and connected from top to bottom to form a tubular structure; the push rod 8 is located in the tubular structure, and the rubber sleeve 3 is sleeved and limited between the bearing assembly 2 and the push rod sleeve 4 outside the push rod 8 (for example, limited by a clamp or a boss structure).

[0031] The lower section of the push rod 8 is provided with external threads matched with internal threads in the push rod seat 5; the lower end of the push rod 8 is connected with the upper end of the valve core 10 through a spherical snap pin 9, and the push rod 8 can drive the valve core 10 to move axially along the tubular structure when the push rod 8 is rotated and the valve core 10 does not rotate with the push rod 8.

[0032] The valve core 10 is slidably accommodated in a cavity formed by the valve core sleeve 6 and the lower joint 7; the side wall and the lower end of the valve core 10 are respectively provided with a lateral hole and a bottom hole for fluid flow, and the side wall of the valve core sleeve 6 is correspondingly provided with a through hole capable of communicating with the lateral hole; the lateral hole of the valve core 10 is a plurality of holes uniformly distributed in the circumferential direction; the valve core sleeve 6 is correspondingly provided with the same number of through holes. The bottom hole of the valve core 10 is a plurality of holes uniformly distributed in the circumferential direction.

[0033] The lower joint 7 simultaneously serves as a valve core seat for limiting the downward terminal point of the valve core 10. When the push rod 8 is in the initial upper position, the rubber sleeve 3 is in a natural state, the lateral hole of the valve core 10 is closed and the bottom hole is open, and the fluid flows through the bottom passage; when the push rod 8 is rotated downward to the bottom, the bearing assembly 2 and the push rod sleeve 4 extrude the rubber sleeve 3 to make it radially expand to seal the well, and at the same time, the valve core 10 moves downward to align the lateral hole with the through hole of the valve core sleeve 6 and the bottom hole is closed, and the fluid flows through the lateral passage.

[0034] In an application example, the sealing device is used to transfer pressure to a depth of 50 m or more in the well, reduce the useless consumption of energy, and concentrate the energy (pressure) in the target layer, thereby reducing the pressure loss and avoiding the damage to the wellhead device.

[0035] Having described above several embodiments of the disclosure, any modifications and variations that fall within the scope of the described embodiments are also intended to be within the scope of the disclosure. As will be apparent to those skilled in the art, some modifications and variations to the embodiments described above can be practiced while staying within the scope and spirit of the described embodiments. The foregoing description of the described embodiments has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the described embodiments to the precise form disclosed. Many modifications and variations are possible in light of the above teachings. It is intended that the disclosed embodiments be limited only by the claims.

Claims

1. A wellbore casing seal apparatus, characterized by, The device comprises an upper joint (1), a bearing assembly (2), a rubber sleeve (3), a push rod sleeve (4), a push rod seat (5), a valve core sleeve (6) and a lower joint (7) arranged in sequence from top to bottom. The upper end of the upper joint (1) is used for connecting a well washing sleeve, and the lower end of the upper joint (1) is fixedly connected with the upper end of a push rod (8); the bearing assembly (2) is installed outside the push rod (8), and the upper joint (1) is not in direct contact with the bearing assembly (2); the push rod sleeve (4), the push rod seat (5) and the valve core sleeve (6) are fixedly connected in sequence from top to bottom to form a tubular structure; the push rod (8) is located in the tubular structure, and the rubber sleeve (3) is sleeved and limited outside the push rod (8) and located between the bearing assembly (2) and the push rod sleeve (4); The lower section of the push rod (8) is provided with external threads matched with internal threads in the push rod seat (5); the lower end of the push rod (8) is connected with the upper end of a valve core (10) through a spherical snap pin (9), and the push rod (8) can drive the valve core (10) to move axially along the tubular structure when the push rod (8) is rotated and the valve core (10) does not rotate with the push rod (8); The valve core (10) is slidably accommodated in a cavity formed by the valve core sleeve (6) and the lower joint (7); the side wall and the lower end of the valve core (10) are respectively provided with a lateral hole and a bottom hole for fluid flow, and the side wall of the valve core sleeve (6) is correspondingly provided with a through hole capable of communicating with the lateral hole; When the push rod (8) is in an initial upper position, the rubber sleeve (3) is in a natural state, the lateral hole of the valve core (10) is closed and the bottom hole is open, and fluid flows through the bottom passage; when the push rod (8) is rotated downward to the bottom, the bearing assembly (2) and the push rod sleeve (4) extrude the rubber sleeve (3) to make it radially expand to seal the well, and at the same time, the valve core (10) moves downward to align the lateral hole with the through hole of the valve core sleeve (6) and close the bottom hole, so that fluid flows through the lateral passage.

2. The apparatus of claim 1, wherein, The lower end of the upper joint (1) is connected with the upper end of the push rod (8) through threads.

3. The apparatus of claim 1, wherein, The limiting mode of the bearing assembly (2) and the push rod sleeve (4) to the rubber sleeve (3) is hoop limiting or boss structure limiting.

4. The apparatus of claim 1, wherein, The external threads of the lower section of the push rod (8) are long thread sections to adapt to the long stroke axial movement of the push rod (8) in the rotating process.

5. The apparatus of claim 1, wherein, The lateral hole of the valve core (10) is a plurality of holes uniformly distributed in the circumferential direction; the valve core sleeve (6) is correspondingly provided with the same number of through holes.

6. The apparatus of claim 1 or 5, wherein, The bottom hole of the valve core (10) is a plurality of holes uniformly distributed in the circumferential direction.

7. The apparatus of claim 1, wherein, The lower joint (7) simultaneously serves as a valve core seat for limiting the downward end point of the valve core (10).

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