Pass-through type concentric double-pipe insertion pipe sealer and double-pipe column

Abstract

The utility model discloses a passable concentric double-pipe intubation sealer and a double-pipe column, the intubation sealer comprises a sealing seat, and one end or two ends of the sealing seat is / are provided with a multi-fastening insertion sealing unit / multiple fastening insertion sealing units / multiple fastening insertion sealing units / multiple fastening insertion sealing units / multiple fastening insertion sealing units / multiple fastening insertion sealing units / multiple fastening insertion sealing units; the multi-fastening insertion sealing unit comprises a sealing counter bore, a sealing assembly, a pressing cap and a connector. The sealing counter bores are formed in one end or two ends of the sealing seat; the sealing assembly is arranged in the sealing counter bore; the pressing cap is connected with the inner wall of the sealing counter bore and tightly presses the sealing assembly, and the end face, away from the sealing assembly, of the pressing cap coincides with the end face of the end of the sealing seat where the pressing cap is located; the connector is connected with the outer wall of the end of the sealing seat, the connector is provided with an inner protruding ring, and the inner protruding ring makes contact with the end face of the pressing cap. The multi-fastening inserting and sealing unit can achieve long-acting sealing, and the maintenance interval time of the pipe column is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of petroleum development technology, specifically a passable concentric double-tube insertion sealer and a double-tube string. Background Technology

[0002] In the development of low-permeability oilfields, stratified injection technology is an effective measure for stable and high production. The concentric dual-tube stratified injection process utilizes a combination of downhole tools, employing tubing of different diameters concentrically downhole for injection. The inner and outer tubing are sealed with a plug-in connection, enabling independent pressure injection into the annulus and inner tubing systems. Each inner and outer tubing system is controlled separately by its own pressure gauge and flow meter, with metering and adjustment performed at the wellhead. This eliminates the need for measurement and adjustment operations, resolving issues such as inter-layer interference and simultaneous injection into high and low pressure zones, improving the success rate of the injection intervals while extending the service life of downhole tools.

[0003] Publication No. CN220151307U discloses an upper sealing device, including an inner hole for the upper sealing device. The inner hole contains guide sleeves and an upper annular sealing element distributed vertically. The upper annular sealing element is used to achieve a seal with the smooth outer wall of the insertion tube through a circumferential sealing fit. The inner circumferential surface of the guide sleeve has an upper guide section, a guide cone surface, and a lower guide section distributed vertically. The inner diameter of the upper guide section is larger than that of the lower guide section, and the inner diameter of the lower guide section is larger than that of the upper annular sealing element. The upper sealing device provided by this utility model uses an internal upper annular sealing element to achieve a seal with the smooth outer wall of the insertion tube through a circumferential sealing fit.

[0004] Publication No. CN213711017U discloses a thermal recovery insert sealer, including a sealing cylinder, a sealing insert, a sealing gasket, and an upper sealing component. The inner wall of the sealing cylinder has a downward-facing stepped surface; the sealing insert is inserted into the inner hole of the sealing cylinder; one or more sealing gaskets are pressed and fixed on the lower stepped surface of the sealing cylinder; the upper sealing component is located above the sealing gasket, and the coefficient of thermal expansion of the upper sealing component is less than that of the sealing gasket.

[0005] Announcement No. CN105156061B discloses a downhole washable well water injection pipe sealing device, including a tubular main connector, a sheath, and a lower connector. The inner diameters of the sheath and the lower connector are equal, and the inner diameter of the tubular main connector is gradually increasing from bottom to top, with its minimum inner diameter equal to the inner diameters of the sheath and the lower connector. The main connector also has an installation hole penetrating the pipe wall, and a one-way valve is installed in the installation hole, allowing unidirectional flow from the outside to the inside of the pipe wall.

[0006] The sealing methods described above have the risk of pressure ring disengagement, weakening or loss of seal during use, and are not suitable for long-term use of concentric double-tube columns.

[0007] In summary, the technical solutions, technical problems to be solved, and beneficial effects of the above-disclosed technologies are all different from those of this utility model. For more technical features, technical problems to be solved, and beneficial effects of this utility model, the above-disclosed technical documents do not provide any technical inspiration. Utility Model Content

[0008] In view of the above-mentioned defects in the existing technology, the purpose of this utility model is to provide a passable concentric double-tube insertion sealer and a double-tube column.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] On the one hand, this utility model provides a passable concentric double tube insertion sealer, including a sealing seat, wherein one or both ends of the sealing seat are provided with multiple fastening insertion units.

[0011] Furthermore, the multiple fastening and sealing unit includes a sealing countersunk hole, a sealing assembly, a pressure cap, and a connector;

[0012] Specifically, the sealing countersunk hole is located at one or both ends of the sealing seat;

[0013] Specifically, the sealing assembly is disposed in the sealing countersunk hole;

[0014] Specifically, the pressure cap is connected to the inner wall of the sealing counterbore, the pressure cap presses the sealing assembly tightly, and the end face of the pressure cap away from the sealing assembly coincides with the end face of the sealing seat.

[0015] Specifically, the connector is connected to the outer wall of the sealing seat end, and the connector is provided with an inner convex ring, which contacts the end face of the pressure cap.

[0016] Furthermore, the pressure cap is threaded to the inner wall of the sealing countersunk hole, and the pressure cap and the sealing seat are locked together by a primary fastener;

[0017] Specifically, the connector is threaded to the outer wall of the sealing seat end, and the connector and the sealing seat are locked together by two-stage fasteners.

[0018] Furthermore, both the primary and secondary fasteners are tapered-end fastening screws, with the primary fastener passing through the sealing seat wall and the secondary fastener passing through the joint wall.

[0019] Furthermore, the connector located above the sealing seat is the upper connector, and the connector located below the sealing seat is the lower connector.

[0020] Furthermore, the end face of the inner convex ring away from the pressure cap is provided with an inclined conical surface.

[0021] Furthermore, the lower connector has a threaded transition short section on its outer wall, and the lower end of the transition short section is used to connect with the oil pipe.

[0022] Secondly, this utility model provides a double-tube column, including an inner tube column and an outer tube column. The inner tube column includes an inner tube, and the lower end of the inner tube is connected to a plug. The outer tube column includes a passable concentric double-tube insertion sealer as described in one aspect. The plug can be sealed with a multiple fastening insertion sealing unit.

[0023] Furthermore, the lower end of the cannula is provided with an outer chamfer.

[0024] Compared with the prior art, the present invention has the following advantages:

[0025] 1. The multi-fastening sealing unit of this utility model can provide long-term sealing and extend the maintenance interval of the tubing column.

[0026] 2. This utility model design adds a transition section and increases the length of the insertion tube seal. The insertion tube, which was originally exposed outside the insertion tube seal, is now retracted into the insertion tube seal. A tapered transition step is added to fix the insertion tube position, allowing the testing instrument to pass smoothly through the insertion tube seal and reducing the risk of testing and construction. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a through-type concentric double-tube insertion and sealing device according to the present invention;

[0028] Figure 2 This is a schematic diagram of the structure of a double-tube column for the application of a passable concentric double-tube insertion sealer according to this utility model;

[0029] Figure 3 This is the result of fiber optic absorption measurement test when water is injected into the oil pipe alone in Embodiment 3 of this utility model;

[0030] Figure 4 This is the result of fiber optic absorption measurement when the inner tube is filled with water alone in Embodiment 3 of this utility model;

[0031] Figure 5 This is the result of fiber optic absorption measurement when water is injected into the inner tube and oil pipe simultaneously in Embodiment 3 of this utility model.

[0032] In the diagram: 1. Coupling; 2. Upper connector; 3. Pressure cap; 4. Insert pipe; 5. Sealing seat; 6. Lower connector; 7. Primary fastener; 8. O-ring seal; 9. Secondary fastener; 10. Sealing assembly; 11. Transition short section;

[0033] 21. Deepening short-circuit joint; 22. Upper reverse-thread safety joint; 23. Hydraulic anchor; 24. Polymer injector; 25. Upper packer; 26. Well-washing valve; 27. A passable concentric double-pipe insert seal; 28. Lower reverse-thread safety joint; 29. ​​Lower packer; 210. Pressure ball seat; 211. Polymer injection screen. Detailed Implementation

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0035] Example 1:

[0036] Please see Figure 1 This embodiment provides a passable concentric double-tube insertion sealer, including a sealing seat 5, wherein one or both ends of the sealing seat 5 are provided with multiple fastening insertion units.

[0037] Furthermore, the multiple fastening and sealing unit includes a sealing countersunk hole, a sealing assembly 10, a pressure cap 3, a connector, a primary fastener 7, and a secondary fastener 9. The sealing countersunk hole is located at one or both ends of the sealing seat 5. The sealing assembly 10 is located in the sealing countersunk hole. The pressure cap 3 is threaded to the inner wall of the sealing countersunk hole. The pressure cap 3 presses the sealing assembly 10 tightly. The end face of the pressure cap 3 away from the sealing assembly 10 coincides with the end face of the sealing seat 5. The pressure cap 3 and the sealing seat 5 are locked together by the primary fastener 7. The connector is threaded to the outer wall of the sealing seat 5. The connector is provided with an inner convex ring. The inner convex ring contacts the end face of the pressure cap 3. The connector and the sealing seat 5 are locked together by the secondary fastener 9.

[0038] Among them, the first-level fastener 7 prevents the pressure cap 3 from loosening, and the second-level fastener 9 prevents the joint from loosening. When the first-level fastener fails and the pressure cap 3 becomes loose, the inner convex ring of the joint plays the role of preventing the pressure cap 3 from becoming looser.

[0039] Specifically, the primary fastener 7 and the secondary fastener 9 are both internal hexagonal tapered end fastening screws. The primary fastener 7 passes through the wall of the sealing seat 5, and the secondary fastener 9 passes through the joint wall.

[0040] Specifically, the joint and the outer wall of the sealing seat 5 are sealed by an O-ring 8.

[0041] Specifically, the connector located above the sealing seat 5 is the upper connector 2, and the connector located below the sealing seat 5 is the lower connector 6.

[0042] Specifically, the end face of the inner convex ring away from the pressure cap 3 is provided with an inclined conical surface to facilitate the guidance of the insertion tube 4.

[0043] Specifically, the lower connector is threadedly connected to a transition short section 11. The transition short section 11 is used to increase the length of the insertion tube seal to ensure that the insertion tube 4 is retracted into the insertion tube seal. The lower end of the transition short section 11 is connected to the oil pipe, ensuring that the testing instrument can smoothly pass through the insertion tube seal from the lower end of the insertion tube 4 and safely transition to the lower connecting oil pipe.

[0044] The insert tube 4 is used for the insertion and sealing of the inner and outer tubing in the concentric double-tube water injection string, achieving a high-pressure seal. The insert tube has an inner diameter of φ40 and is made of 42CrMo material.

[0045] Among them, the sealing seat 5 is used to seal the annular space between the inner tube and the oil tube in the concentric double-pipe water injection string; the sealing seat 5, the upper connector 2, and the lower connector 6 are made of 42CrMo material, the pressure cap 3 is made of N80 material; the transition short section 11 is made of 42CrMo material.

[0046] Furthermore, to facilitate the smooth passage of the logging instrument through the insertion tube 4, the inner diameter of the insertion tube 4 is increased, and an outer chamfer is designed at the lower end of the insertion tube 4. A tapered transition step is provided on the outer wall of the insertion tube 4. After the insertion tube 4 is inserted into the sealing seat 5, the outer chamfer and the inclined tapered surface of the inner convex ring of the upper connector 2 guide each other, allowing the insertion tube 4 to be smoothly inserted into the sealing seat 5. The tapered transition step and the inclined tapered surface of the inner convex ring of the upper connector 2 cooperate to fix the position of the insertion tube 4, facilitating the smooth lifting and lowering of the testing instrument at the connection point. This reduces construction risks.

[0047] Through the above design, the various components work together to form a highly efficient, safe, and permissible insertion and sealing device, meeting the retrofit requirements. It possesses excellent practicality and innovation.

[0048] Example 2:

[0049] like Figure 2 As shown, based on Embodiment 1, this embodiment provides a dual-pipe string, including an inner pipe string and an outer pipe string. The inner pipe string includes an inner pipe, the lower end of which is connected to a plug 4. The outer pipe string includes, in sequence from top to bottom, a depth correction short connector 21, an upper reverse-thread safety connector 22, a hydraulic anchor 23, a polymer injector 24, an upper packer 25, a well-washing valve 26, a passable concentric dual-pipe insertion seal 27, a lower reverse-thread safety connector 28, a lower packer 29, a pressure ball seat 210, and a polymer injection screen 211.

[0050] In use, the outer tubing string is lowered into the well, with the upper packer 25 and lower packer 29 positioned between oil layer 1 and oil layer 2 for setting and anchoring. Then, the inner tubing string is lowered into the well, and the lowering position is determined according to the injection depth and the depth correction short connector 21. The insertion pipe 4 is then inserted into the sealing seat 5 of a passable concentric double-tube insertion pipe sealer 27 to achieve effective sealing between the insertion pipe 4 and the annular injection of the tubing. The testing instrument can pass smoothly through the inner tubing string to achieve water intake profile testing of the concentric double-tube water injection well.

[0051] It should be noted that the aforementioned depth correction short connector 21, upper reverse-thread safety connector 22, hydraulic anchor 23, polymer injector 24, upper packer 25, well washing valve 26, lower reverse-thread safety connector 28, lower packer 29, pressure ball seat 210, and polymer injection screen 211 are all existing technologies. Their functions and structures are clear to those skilled in the art, so they will not be described in detail here.

[0052] Example 3:

[0053] This embodiment provides an application example.

[0054] QDQD5-2-X6 is a two-sealed, three-matched sub-injection well. This well is a high-pressure, low-permeability injection well. During operation, the tubing string described in Example 2 was used. After construction, fiber optic water absorption testing was performed, including tests for water absorption when the tubing was injected alone, when the inner tubing was injected alone, and when both the inner tubing and tubing were injected simultaneously. Based on the test curves, the water absorption of each sub-layer was analyzed, and the results were obtained as follows: Figures 3-5 The results are shown.

[0055] The water absorption profile test data matched the actual production situation of the well group, which is of great significance for formulating water injection adjustment and optimization measures for the 5-X6 well group. After the test results were applied, the well group achieved a good result of increasing oil production by 327 tons per year.

[0056] This invention enables the application of fiber optic logging technology in injection profile testing within concentric double-tube systems, allowing for effective evaluation of the injection status and demonstrating promising prospects for wider application.

[0057] It should be noted that the testing methods and instruments are existing technologies, which are clear to those skilled in the art.

[0058] All components not discussed in detail in this application, as well as the connection methods of these components, are well-known technologies in this field. They can be directly applied and will not be elaborated further.

[0059] In this utility model, the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; "linking" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0060] In the description of this utility model, it should be understood that the terms "upper", "lower", "left", "right", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or unit referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0061] In the description of this specification, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0062] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A permeable concentric double-tube insertion sealer, comprising a sealing seat, characterized in that, One or both ends of the sealing seat are provided with multiple fastening and sealing units; The multiple fastening and sealing unit includes a sealing countersunk hole, a sealing assembly, a pressure cap, and a connector; The sealing countersunk hole is located at one or both ends of the sealing seat; The sealing assembly is disposed in the sealing countersunk hole; The pressure cap is connected to the inner wall of the sealing countersunk hole, the pressure cap presses the sealing assembly tightly, and the end face of the pressure cap away from the sealing assembly coincides with the end face of the sealing seat. The connector is connected to the outer wall of the sealing seat end, and the connector is provided with an inner convex ring, which contacts the end face of the pressure cap.

2. The permeable concentric double-tube insertion sealing device according to claim 1, characterized in that, The pressure cap is threaded to the inner wall of the sealing counterbore, and the pressure cap and the sealing seat are locked together by a primary fastener; The connector is threaded to the outer wall of the sealing seat end, and the connector and the sealing seat are locked together by two-stage fasteners.

3. A permeable concentric double-tube insertion sealing device according to claim 2, characterized in that, Both the primary and secondary fasteners are tapered-end fastening screws. The primary fastener passes through the sealing seat wall, and the secondary fastener passes through the joint wall.

4. A permeable concentric double-tube insertion sealing device according to claim 1, characterized in that, The connector located above the sealing seat is the upper connector, and the connector located below the sealing seat is the lower connector.

5. A permeable concentric double-tube insertion sealing device according to claim 1, characterized in that, The end face of the inner convex ring away from the pressure cap is provided with an oblique conical surface.

6. A permeable concentric double-tube insertion sealing device according to claim 4, characterized in that, The lower connector has a threaded transition section on its outer wall, and the lower end of the transition section is used to connect to the oil pipe.

7. A dual-tube column, comprising an inner column and an outer column, wherein the inner column includes an inner tube, and a plug is connected to the lower end of the inner tube, characterized in that, The outer tubing includes a permeable concentric double-tube insertion sealer as described in any one of claims 1-6, wherein the plug is capable of sealing with a multiple fastening sealing unit.

8. A double-tube tubing string according to claim 7, characterized in that, The lower end of the cannula is chamfered.

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