Oil well sealing device

Abstract

The utility model relates to the field of oil well sealing, in particular to an oil well sealing device. The oil well sealing device comprises a base pipe, extrusion rings are arranged at the positions, located at the two ends of each sealing ring, of the base pipe, at least one of the extrusion rings at the two ends of each sealing ring is slidably arranged on the base pipe in a sleeving mode, and the end face of at least one end of each sealing ring is in conical face fit with the end face of the corresponding extrusion ring. Due to the fact that the end faces of the sealing rings are matched with the conical faces of the end faces of the corresponding extrusion rings, when the extrusion rings are stressed to extrude the sealing rings in the middle, the sealing rings can expand outwards under the action of the conical faces till the sealing rings are expanded to the inner wall of the sleeve, and at the moment, the deformation amount of the sealing rings is equal to the radial thickness of the sealing rings. In other words, the radial thickness of the sealing ring can be reduced, and occupation on the inner diameter of the base pipe is reduced; therefore, the problems that in the prior art, a packer extrudes a rubber sleeve, the length of the rubber sleeve is reduced, the thickness of the rubber sleeve is increased, the initial thickness of the rubber sleeve is large, the inner diameter of a base tube is affected, and use of a setting tool is limited are solved.

Description

Technical Field

[0001] The utility model relates to the field of oil well sealing, in particular to an oil well sealing device. Background Art

[0002] Oil wells generally extend a long distance downward from the ground, and pass through different geological layers or oil layers in the process of extending downward. In order to facilitate the collection of oil, the prior art usually sets packers between oil layers when the oil well pressure is insufficient to separate different oil layers, thereby avoiding mixing and conflict between different oil layers.

[0003] A packer is a sealing device used between casing and wellbore or between casing and casing. For example, a Chinese utility model patent with authorization announcement number CN211851762U and authorization announcement date of November 3, 2020 discloses an oil well segmented packer that meets the requirements of segmented fracturing construction, wherein the packer includes a center pipe and a long rubber cylinder and a short rubber cylinder (i.e., a rubber cylinder) sleeved on the outer circumferential surface of the center pipe, and an upper joint is provided above the rubber cylinder and cooperates with the end face stop of the rubber cylinder, and a cylinder sleeve inner tube and a cylinder sleeve outer tube are provided below the rubber cylinder and cooperate with the lower end face stop of the rubber cylinder. When sealing is required, high-pressure liquid is introduced into the cylinder sleeve inner tube to squeeze the rubber cylinder, shorten the length of the rubber cylinder, and expand toward the periphery to complete the sealing.

[0004] In the above technical solution, the packer is completed by the expansion deformation of the rubber tube. Since the deformation amount of the rubber tube is limited, in order to facilitate the rubber tube to effectively block the annulus between the pipe string and the casing when it is squeezed and deformed, the rubber tube needs to have a certain initial radial thickness. For example, in the prior art, in order to facilitate going down the well, a 5mm gap will be left between the outer circumference of the rubber tube and the casing, and in order to fill the gap during the deformation of the rubber tube, the radial thickness of the rubber tube generally needs to be set to 30mm. The rubber tube is sleeved on the outer circumference of the base pipe, and a rubber tube with too large radial thickness will inevitably affect the inner diameter of the base pipe. When setting the seal, it is necessary to extend the sealing tool into the interior of the base pipe. The smaller inner diameter of the base pipe will make some larger-sized sealing tools unusable, and even require the development of a separate sealing tool, resulting in limited operation. Utility Model Content

[0005] The utility model aims to provide an oil well sealing device for solving the problem in the prior art that the packer squeezes the rubber sleeve to reduce the length and increase the thickness of the rubber sleeve for sealing, resulting in a large initial thickness of the rubber sleeve, which affects the inner diameter of the base pipe and limits the use of the sealing tool.

[0006] In order to achieve the above-mentioned purpose, the oil well sealing device in the utility model adopts the following technical scheme:

[0007] An oil well sealing device comprises a base pipe, at least one sealing ring is sleeved on the outer peripheral surface of the base pipe, and extrusion rings for extruding the sealing rings are arranged at both ends of each sealing ring on the base pipe, at least one of the extrusion rings at both ends of the sealing ring is slidably sleeved on the base pipe, the end surface of at least one end of the sealing ring is matched with the end surface of the corresponding extrusion ring in a conical surface, and the conical surface of the extrusion ring is located inside the conical surface of the sealing ring, so that when the slidable extrusion ring is subjected to an axial external force, the middle sealing ring is tightened to the inner wall of the casing through the two extrusion rings.

[0008] Furthermore, at least two sealing rings are provided, at least one sealing ring is a metal sealing ring, and at least one sealing ring is a rubber sealing ring.

[0009] Furthermore, the end faces at both ends of the metal sealing ring and the end faces of the corresponding extrusion rings are both conical surfaces.

[0010] Furthermore, the metal sealing ring and the rubber sealing ring share the same extrusion ring to form a common extrusion ring, the end face of the common extrusion ring facing the rubber sealing ring is arranged perpendicular to the axis of the base pipe, and there is planar contact between the end faces of the common extrusion ring and the rubber sealing ring.

[0011] Furthermore, the rubber sealing ring is a sealing ring located at the top of the base tube. A boss is integrally provided on the base tube at a side of the rubber sealing ring away from the common extrusion ring. The boss constitutes the top extrusion ring on the base tube, and a conical surface fit is formed between the boss and the rubber sealing ring.

[0012] Furthermore, the hardness of at least one of the extrusion rings at both ends of the metal sealing ring is smaller than the hardness of the base pipe.

[0013] Furthermore, the base pipe is a steel pipe, each metal sealing ring is a copper ring, and the extrusion rings located on both sides of the metal sealing ring are brass rings.

[0014] Furthermore, a locking ring is provided on the base pipe at the lower side of the lowermost extrusion ring to keep each sealing ring in a deformed state.

[0015] Furthermore, a pressure transmission tube is sleeved on the base tube between the locking ring and the lowest extrusion ring, and the pressure transmission tube is fixed to the base tube by shear pins. The end faces of the lowest extrusion ring and the locking ring that are respectively pushed together with the pressure transmission tube and both end faces of the pressure transmission tube are flat.

[0016] Furthermore, the outer diameters of each extrusion ring and each sealing ring are equal when they are not set.

[0017] The beneficial effects of the oil well sealing device of the utility model are as follows: the utility model improves the existing oil well sealing device, and facilitates sealing by arranging a sealing ring. Since at least one of the extrusion rings at both ends of the sealing ring is slidingly sleeved on the base pipe, the spacing between two adjacent extrusion rings can be adjusted, and then the sealing ring between the two extrusion rings is squeezed; since the end face of at least one end of the sealing ring is matched with the end face of the corresponding extrusion ring as a conical surface, when the extrusion ring is subjected to force so that the two extrusion rings squeeze the sealing ring in the middle, the sealing ring will expand outwards under the action of the conical surface until it is tightened to the inner wall of the casing, and the deformation amount of the sealing ring is equal to the radial thickness of the sealing ring itself, that is, the radial thickness of the sealing ring can be reduced, and the occupation of the inner diameter of the base pipe can be reduced; since the sealing ring no longer needs to be shortened in length to increase the thickness during the sealing process of the sealing ring, the initial thickness of the sealing ring can be reduced, thereby solving the problem that the packer in the prior art squeezes the rubber sleeve to reduce the length and increase the thickness of the rubber sleeve for sealing, resulting in a large initial thickness of the rubber sleeve, affecting the inner diameter of the base pipe and limiting the use of the setting tool. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of an embodiment of the oil well sealing device in the utility model.

[0019] In the figure: 1, base pipe; 2, boss; 3, rubber sealing ring; 4, common extrusion ring; 5, metal sealing ring; 6, first extrusion ring; 7, shear pin; 8, pressure transmission tube; 9, locking ring; 10, connecting tube. DETAILED DESCRIPTION

[0020] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0021] In the utility model, a sealing ring and a conical surface for guiding the movement of the sealing ring are arranged on the outer peripheral surface of the base pipe, so that the sealing ring can expand outward without changing its length, thereby making it unnecessary to set the sealing ring to a larger thickness.

[0022] In the embodiment of the oil well sealing device of the utility model:

[0023] like Figure 1As shown, the oil well sealing device in this embodiment includes a base pipe 1, which is arranged along the oil well, and a casing is also arranged on the outside of the base pipe 1. A sealing ring is sleeved on the outer circumferential surface of the base pipe 1, and at least one sealing ring is provided, and both ends of each sealing ring are provided with an extrusion ring for extruding the sealing ring, and at least one of the two extrusion rings at both ends of each sealing ring is slidably arranged on the base pipe 1. In order to facilitate the deformation of the sealing ring, a conical surface in contact with the sealing ring is provided on at least one of the two extrusion rings at both ends of each sealing ring, and the sealing ring cooperates with the conical surface of the extrusion ring with a conical surface, so that the sealing ring is sleeved on the outer circumference of at least one extrusion ring under extrusion. Of course, in other embodiments, conical surfaces can also be formed on the two extrusion rings at both ends of each sealing ring.

[0024] Specifically, two sealing rings are provided, and the two sealing rings are respectively a metal sealing ring 5 and a rubber sealing ring 3, and the metal sealing ring 5 and the rubber sealing ring 3 are arranged at intervals. A common extrusion ring 4 is also provided between the metal sealing ring 5 and the rubber sealing ring 3. The two ends of the common extrusion ring 4 are used to contact the metal sealing ring 5 and the rubber sealing ring 3 respectively. The two ends of the common extrusion ring 4 respectively form a second extrusion ring for extruding the metal sealing ring 5 and a third sealing ring for extruding the rubber sealing ring 3. In order to facilitate better extrusion of the two sealing rings, a first extrusion ring 6 is provided at one end of the metal sealing ring 5 away from the common extrusion ring 4, and the first extrusion ring 6 can slide relative to the base pipe 1. A fourth extrusion ring is also provided at one end of the rubber sealing ring 3 away from the common extrusion ring 4. In this embodiment, the common extrusion ring 4 is slidably provided on the outer peripheral surface of the base pipe 1, and a boss 2 is also provided on the base pipe 1 on the outer side of the rubber sealing ring 3, and a step structure is formed on the boss 2, and the boss 2 also forms a fourth extrusion ring located on the outer side of the rubber sealing ring 3. Of course, in other embodiments, the first extrusion ring 6 may be configured as the boss 2, and the fourth extrusion ring may be configured to be movable.

[0025] Alternatively, in other embodiments, the first extrusion ring 6 and the fourth extrusion ring may also be set to be movable. In this case, a common extrusion ring 4 that can move relative to the base tube 1 may be set as the second extrusion ring and the third extrusion ring, or a common extrusion ring 4 fixed on the base tube 1 may be set to form the second extrusion ring and the third extrusion ring. Alternatively, in other embodiments, multiple sealing rings may be set, such as two metal sealing rings 5 ​​and one rubber sealing ring 3 or two rubber sealing rings 3 and one metal sealing ring 5. Alternatively, in other embodiments, only one metal sealing ring 5 or only one rubber sealing ring 3 may be set. It is worth noting that the number of extrusion rings should be twice that of sealing rings. When the number of sealing rings changes, the number of extrusion rings should also be adjusted adaptively.

[0026] Specifically, in this embodiment, the first extrusion ring 6 and the second extrusion ring are both provided with a conical surface, and the two ends of the metal sealing ring 5 are also provided with a conical surface. The third extrusion ring has a flush extrusion end, and the fourth extrusion ring is provided with a conical surface, so the rubber sealing ring 3 is only provided with a conical surface in the portion that cooperates with the fourth extrusion ring. The second extrusion ring and the third extrusion ring are formed on the common extrusion ring 4 at the same time. If the metal sealing ring 5 and the rubber sealing ring 3 are deformed at the common extrusion ring 4 at the same time, the metal sealing ring 5 and the rubber sealing ring 3 may interfere with each other on the outer peripheral surface of the common extrusion ring 4, so the common extrusion ring 4 is only provided with a conical surface at one end. It is worth noting that in order to facilitate the placement of the oil well sealing device underground, the outer diameters of each extrusion ring and each sealing ring are equal when they are not set, so that when the oil well sealing device is placed in the oil well, the distance between each part and the casing is equal. Of course, in other embodiments, the thickness of the sealing ring can also be set to be greater than the thickness of the extrusion ring.

[0027] During the deformation process of the sealing ring, the inner diameter and outer diameter of the sealing ring are synchronously enlarged by the extrusion ring, thereby forming a seal between the base pipe 1 and the casing. In order to better allow the sealing ring to deform, the hardness of the sealing ring is less than the hardness of the extrusion ring where the conical surface is located. Specifically, the first extrusion ring 6, the second extrusion ring and the third extrusion ring are all brass extrusion rings made of brass, the metal sealing ring 5 is a copper ring made of copper, and the fourth extrusion ring is a steel extrusion ring integrally formed with the base pipe 1. Of course, in other embodiments, the sealing ring can also be set to an aluminum ring, and the extrusion ring can be set to a copper extrusion ring. Of course, in other embodiments, the sealing ring and the extrusion ring can also be set to copper.

[0028] When sealing the casing and the base pipe 1, the sealing ring will move to the outside of the extrusion ring, such as the first extrusion ring 6 and the metal sealing ring 5. At this time, if the sealing is to be completed, the first extrusion ring 6 and the base pipe 1 need to be well sealed, and the metal sealing ring 5 and the casing need to be well sealed, so the hardness of the first extrusion ring 6 is less than the hardness of the base pipe 1. Of course, in other embodiments, the first extrusion ring 6 and the base pipe 1 can also be set to be made of steel, and the second extrusion ring can be set to be a copper extrusion ring with a hardness less than that of the base pipe 1.

[0029] The fourth extrusion ring is integrally formed with the base tube 1. If the extrusion ring and the sealing ring are to be pushed to move relative to each other, the first extrusion ring 6 needs to move relative to the base tube 1. Specifically, a pressure transmission tube 8 for pushing the first extrusion ring 6 toward the metal sealing ring 5 is also provided at one end of the first extrusion ring 6 away from the metal sealing ring 5, that is, the pressure transmission tube 8 is arranged at the lower end to facilitate the pressure transmission tube 8 and the boss 2 on the base tube 1 to approach each other. In order to prevent the sealing ring and the extrusion ring from moving relative to each other when sealing is not required, a perforation is also provided on the pressure transmission tube 8, and a mounting hole matching the perforation is provided on the base tube 1. Fasteners are provided in the perforation and the mounting hole to make the pressure transmission tube 8 and the base tube 1 relatively stationary. The fastener is a shear pin 7 that can be sheared off. The end faces of the first extrusion ring 6 (i.e., the lowermost extrusion ring) and the lock ring 9 that are respectively pushed and matched with the pressure transmission tube 8 and the two end faces of the pressure transmission tube 8 are both planes.

[0030] In order to prevent the sealing ring from retreating after the sealing is completed, a lock ring 9 is also provided on the side of the base tube 1 located at the pressure transmission tube 8 away from the first extrusion ring 6. The surface of the lock ring 9 is processed with a one-way anti-slip structure, and can only move in one direction with the base tube 1. That is, when it is necessary to seal and move the lock ring 9 close to the sealing ring, the lock ring 9 can move. When the sealing ring completes the sealing, the lock ring 9 cannot retreat at this time and can only remain in place, thereby maintaining the deformation state of each sealing ring. It is worth noting that a connecting tube 10 is also provided on the outside of the lock ring 9, and the connecting tube 10 protrudes from the end of the base tube 1 so that part of the inner surface of the connecting part is exposed. Of course, in other embodiments, the lock ring 9 may not be provided, and the friction between the sealing ring and the extrusion ring may be used for self-locking. Alternatively, in other embodiments, the pressure transmission tube 8 may not be provided, so that the lock ring 9 directly abuts against the end of the first extrusion ring 6.

[0031] When sealing is required, an oil pipe is placed in the base pipe 1, and an upper hydraulic anchor, a lower hydraulic anchor and a hydraulic booster are arranged on the outer circumference of the oil pipe. The upper hydraulic anchor and the lower hydraulic anchor are locked on the inner circumference of the base pipe 1 and the inner circumference of the connecting tube 10 respectively. At this time, the upper hydraulic anchor and the base pipe 1 are fixedly connected, and the lower hydraulic anchor and the connecting tube 10 are fixedly connected. Under the action of the hydraulic booster, the upper hydraulic anchor and the lower hydraulic anchor are close to each other, which only makes the end of the connecting tube 10 and the boss 2 of the base pipe 1 close to each other. At this time, the connecting tube 10 drives the lock ring 9 to move toward the boss 2, and then drives the pressure transmission tube 8 to cut the shear pin 7 to move, thereby driving the first extrusion ring 6 to move. The first extrusion ring 6 moves close to the boss 2. Under the action of the guiding inclined surface and the matching inclined surface, the rubber sealing ring 3 slides on the boss 2 of the base pipe 1, and the metal sealing ring 5 slides on the outer circumference of the first extrusion ring 6 and the second extrusion ring to complete the sealing. The metal sealing ring 5 has a relatively high hardness and is easy to adapt to a large pressure, while the rubber sealing ring 3 has a relatively soft texture and is easy to fit between the base pipe 1 and the casing. Even if the surface between the base pipe 1 and the casing is uneven, a good seal can be achieved. It is worth noting that the use of hydraulic anchors belongs to conventional technical means. For details, please refer to the method for using hydraulic anchors in a long well section reinforcement device with application publication number CN115217432A.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. The patent protection scope of the present invention shall be based on the claims. All equivalent structural changes made using the description and drawings of the present invention shall be included in the protection scope of the present invention.

Claims

1. An oil well sealing device, comprising a base pipe, at least one sealing ring is sleeved on the outer peripheral surface of the base pipe, and extrusion rings for extruding the sealing rings are arranged at both ends of each sealing ring on the base pipe, and at least one of the extrusion rings at both ends of the sealing ring is slidingly sleeved on the base pipe, characterized in that: The end surface of at least one end of the sealing ring is conically matched with the end surface of the corresponding extrusion ring, and the conical surface of the extrusion ring is located inside the conical surface of the sealing ring, so that when the slidable extrusion ring is subjected to axial external force, the middle sealing ring is tightened to the inner wall of the sleeve through the two extrusion rings.

2. The oil well sealing device according to claim 1, characterized in that: At least two sealing rings are provided, at least one sealing ring is a metal sealing ring, and at least one sealing ring is a rubber sealing ring.

3. The oil well sealing device according to claim 2, characterized in that: The end faces at both ends of the metal sealing ring and the end faces of the corresponding extrusion rings are both conical surfaces.

4. The oil well sealing device according to claim 2 or 3, characterized in that: The metal sealing ring and the rubber sealing ring share the same extrusion ring to form a common extrusion ring. The end face of the common extrusion ring facing the rubber sealing ring is arranged perpendicular to the axis of the base pipe. The common extrusion ring and the end face of the rubber sealing ring are in planar contact.

5. The oil well sealing device according to claim 4, characterized in that: The rubber sealing ring is located at the top of the base tube. A boss is integrally provided on the base tube at the side of the rubber sealing ring away from the common extrusion ring. The boss constitutes the top extrusion ring on the base tube, and a conical surface fit is formed between the boss and the rubber sealing ring.

6. The oil well sealing device according to claim 2 or 3, characterized in that: The hardness of at least one of the extrusion rings at both ends of the metal sealing ring is smaller than the hardness of the base pipe.

7. The oil well sealing device according to claim 6, characterized in that: The base pipe is a steel pipe, each metal sealing ring is a copper ring, and the extrusion rings located on both sides of the metal sealing ring are brass rings.

8. The oil well sealing device according to any one of claims 1 to 3, characterized in that: A locking ring is also provided on the base pipe at the lower side of the lowermost extrusion ring to keep each sealing ring in a deformed state.

9. The oil well sealing device according to claim 8, characterized in that: A pressure transmission tube is sleeved on the base tube between the locking ring and the lowest extrusion ring. The pressure transmission tube is fixed to the base tube by shear pins. The end faces of the lowest extrusion ring and the locking ring respectively pushing against the pressure transmission tube and the two end faces of the pressure transmission tube are both planes.

10. The oil well sealing device according to any one of claims 1 to 3, characterized in that: The outer diameters of the extrusion rings and the sealing rings are equal when they are not set.

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