Straight-through type telescopic thermal recovery casing head

Abstract

The utility model relates to the technical field of petroleum drilling casing heads, in particular to a straight-through type telescopic thermal recovery casing head which comprises a fixed sealing seat in threaded connection with the inner surface of the casing head, a telescopic sealing pipe is arranged on the inner surface of the fixed sealing seat, and a limiting step is arranged at the outer circle end of the telescopic sealing pipe. The inner side of the lower end of the casing head is in threaded connection with an elastic scraping assembly, the elastic scraping assembly comprises a connecting disc, an annular groove is formed in the inner surface of the connecting disc, a sleeve column is fixedly installed on the inner surface of the annular groove, the outer surface of the sleeve column is sleeved with an annular scraping plate, and the upper connecting end and the lower connecting end of the annular scraping plate and the sleeve column are sleeved with springs. The device has the beneficial effects that the effect that the fixed sealing seat is pressed again when the sleeve retracts to form sealing guarantee is achieved, the upper coupling is prevented from making contact with the fixed sealing seat to form large-torque friction force, the upper coupling is convenient to replace, impurities are prevented from moving in fluid to rub the outer wall of a pipeline, the service life of the pipeline is prolonged, and the production cost is reduced.

Description

Technical Field

[0001] This utility model relates to the field of oil drilling casing heads, specifically a straight-through retractable thermal recovery casing head. Background Technology

[0002] Thermal recovery casing heads used in oil drilling and heavy oil extraction typically employ a slip-type structure to fix the surface casing and oil layer casing of the oil well, or a telescopic structure for direct connection.

[0003] In existing oil drilling and extraction processes, steam is injected underground to heat the oil layer and reduce the viscosity of crude oil. When steam is injected into the oil layer, the temperature inside the wellbore gradually rises. In order to prevent the casing from expanding due to the temperature rise and generating excessive pressure or deformation, the telescopic casing is allowed to vary in length within a certain range.

[0004] However, when the expansion sleeve retracts due to temperature drop, it causes the upper coupling to contact the fixed sealing seat, creating a large torque frictional force. This makes it difficult to replace the upper coupling. Furthermore, during the reciprocating sliding process, debris easily adheres to the outer wall of the expansion sleeve, which may hinder the free expansion and contraction of the sleeve. Additionally, hard impurities moving in the fluid can cause friction on the outer wall of the pipe, which over time can lead to increased pipe wear and shorten its service life. Utility Model Content

[0005] The purpose of this utility model is to provide a straight-through retractable thermal extraction sleeve head to solve the problems mentioned in the background art, such as the upper coupling contacting the fixed sealing seat when the retractable sleeve retracts due to temperature reduction, resulting in a large torque friction force, making it difficult to replace the upper coupling, and the easy adhesion of debris to the outer wall of the reciprocating sleeve during the sliding process, which may hinder the free expansion and contraction of the sleeve, and the friction caused by hard impurities moving in the fluid, which will lead to increased wear and tear on the pipe and shorten its service life in the long run.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a straight-through retractable thermal recovery sleeve head, comprising:

[0007] The sleeve head has a fixed sealing seat threaded on its inner surface. The inner surface of the fixed sealing seat is provided with a telescopic sealing tube, and the outer end of the telescopic sealing tube is provided with a limit step.

[0008] The lower end of the sleeve head is threaded with an elastic scraping assembly. The elastic scraping assembly includes: a connecting disc, an annular groove on the inner surface of the connecting disc, a sleeve post fixedly installed on the inner surface of the annular groove, an annular scraper on the outer surface of the sleeve post, and springs on the upper and lower connecting ends of the annular scraper and the sleeve post.

[0009] Preferably, the telescopic sealing tube is provided with an upper coupling and a lower coupling at its upper and lower ends. The inner surfaces of the upper coupling and the lower coupling are provided with internal threads, and the outer surfaces of the upper and lower ends of the telescopic sealing tube are provided with external threads. The telescopic sealing tube is threadedly connected to the inner threads of the upper coupling and the lower coupling through the external threads.

[0010] Preferably, the side surface of the sleeve head is provided with a plurality of threaded holes, and the inner surface of the threaded holes is threaded with a stop screw, which is threadedly connected to the fixed sealing seat.

[0011] Preferably, the annular scraper and the sleeve are slidably connected by a spring, and the inner wall of the annular scraper is in contact with the outer wall of the telescopic sealing tube.

[0012] Preferably, the central end of the sleeve head is threaded with overflow pipes on both sides, and the lower surface of the overflow pipes is provided with overflow holes.

[0013] Preferably, the lower inner wall of the sleeve head is fixedly equipped with several sets of mounting bosses, and the outer wall of the connecting plate is provided with several sets of mounting slots, which are engaged with the mounting bosses.

[0014] Preferably, a sealing groove is provided at the connection between the sleeve head and the telescopic sealing tube, and a sealing strip is provided on the inner surface of the sealing groove.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This utility model proposes a straight-through retractable thermal extraction sleeve head;

[0017] 1. By setting a limiting step on the outer circle of the telescopic sealing tube, the fixed sealing seat can be pressed again when the sleeve retracts, thus forming a sealing guarantee effect. This also avoids the upper coupling from contacting the fixed sealing seat and forming a large torque friction force, making it easier to replace the upper coupling.

[0018] 2. By setting up an elastic scraping component, during the up-and-down sliding process of the telescopic sealing pipe, the annular scraper cleans the hard impurities adhering to the outer wall of the telescopic sealing pipe. When the hard impurities come into contact with the annular scraper, the elasticity of the spring drives the annular scraper in the annular groove to slide up and down on the outer surface of the sleeve column, thereby cleaning the hard impurities on the outer wall of the telescopic sealing pipe, preventing the hard impurities from moving in the fluid and causing friction on the outer wall of the pipe, thus extending the service life of the pipe and reducing production costs. Attached Figure Description

[0019] Figure 1 This is an internal sectional view of the overall structure of this utility model;

[0020] Figure 2 This is a side sectional view of the present invention;

[0021] Figure 3 For the present utility model Figure 2 Enlarged view of point A in the middle;

[0022] Figure 4 This is a schematic diagram of the internal structure of the sleeve head of this utility model;

[0023] Figure 5 For the present utility model Figure 4 Enlarged view at point B in the middle;

[0024] Figure 6 This is a partial structural schematic diagram of the present invention;

[0025] Figure 7 This is a schematic diagram of the elastic scraping component structure of this utility model.

[0026] In the diagram: 1. Upper coupling; 2. Stop screw; 3. Fixed sealing seat; 4. Sleeve head; 5. Telescopic sealing tube; 6. Lower coupling; 7. Limiting step; 8. External thread; 9. Internal thread; 10. Overflow pipe; 11. Connecting disc; 12. Annular groove; 13. Sleeve post; 14. Annular scraper; 15. Spring; 16. Mounting slot; 17. Mounting boss; 18. Sealing groove; 19. Sealing strip; 20. Threaded hole. Detailed Implementation

[0027] 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.

[0028] Please see Figures 1 to 7 This utility model provides a technical solution: a straight-through retractable thermal extraction sleeve head;

[0029] Example 1:

[0030] To ensure a tight seal when the casing retracts, preventing the upper coupling 1 from contacting the fixed sealing seat 3 and generating high-torque friction, a fixed sealing seat 3 is threaded onto the inner surface of the casing head 4. A telescopic sealing tube 5 is installed on the inner surface of the fixed sealing seat 3. A limiting step 7 is provided at the outer end of the telescopic sealing tube 5. Upper couplings 1 and lower couplings 6 are located at the upper and lower ends of the telescopic sealing tube 5. Internal threads 9 are provided on the inner surfaces of upper couplings 1 and lower couplings 6, and external threads 8 are provided on the outer surfaces of both ends of the telescopic sealing tube 5. The telescopic sealing tube 5 is threaded to the internal threads 9 on the inner surfaces of upper couplings 1 and lower couplings 6 via the external threads 8. By providing the limiting step 7 on the outer circumference of the telescopic sealing tube 5, the fixed sealing seat 3 can be tightened again when the casing retracts, ensuring a tight seal and preventing the upper coupling 1 from contacting the fixed sealing seat 3 and generating high-torque friction, thus facilitating the replacement of the upper coupling 1.

[0031] Example 2:

[0032] To effectively scrape away hard impurities adhering to the outer wall of the telescopic sealing tube 5 during its up-and-down sliding motion, an elastic scraping assembly is threaded onto the inner side of the lower end of the sleeve head 4. This elastic scraping assembly includes: a connecting disc 11, an annular groove 12 on the inner surface of the connecting disc 11, a sleeve post 13 fixedly mounted on the inner surface of the annular groove 12, an annular scraper 14 fitted onto the outer surface of the sleeve post 13, and springs 15 fitted onto the upper and lower connecting ends of the annular scraper 14 and the sleeve post 13. The annular scraper 14 and the sleeve post 13 are slidably connected via the springs 15. The inner wall of the annular scraper 14 contacts the outer wall of the telescopic sealing tube 5, and the inner wall of the lower end of the sleeve head 4 is fixed. Several sets of mounting bosses 17 are installed, and several sets of mounting slots 16 are opened on the outer wall of the connecting plate 11. The mounting slots 16 are engaged with the mounting bosses 17. During the up-and-down sliding process of the telescopic sealing pipe 5, the annular scraper 14 scrapes away the hard impurities attached to the outer wall of the telescopic sealing pipe 5. When the hard impurities come into contact with the annular scraper 14, the elasticity of the spring 15 drives the annular scraper 14 in the annular groove 12 to slide up and down on the outer surface of the sleeve column 13, thereby cleaning the hard impurities on the outer wall of the telescopic sealing pipe 5, preventing the hard impurities from moving in the fluid and causing friction on the outer wall of the pipe, thereby increasing the service life of the pipe and reducing production costs.

[0033] Working Principle: When using this device, in order to achieve the effect of re-pressing the fixed sealing seat 3 when the sleeve retracts to form a sealing guarantee, and to avoid the upper coupling 1 contacting the fixed sealing seat 3 and forming a large torque frictional force, a limiting step 7 is set on the outer circle of the telescopic sealing tube 5. This achieves the effect of re-pressing the fixed sealing seat 3 when the sleeve retracts to form a sealing guarantee, and avoids the upper coupling 1 contacting the fixed sealing seat 3 and forming a large torque frictional force, making it easier to replace the upper coupling 1. In order to scrape away the hard impurities attached to the outer wall of the telescopic sealing tube 5 during the up and down sliding process of the telescopic sealing tube 5, the annular scraper 14 scrapes away the hard impurities attached to the outer wall of the telescopic sealing tube 5 during the up and down sliding process of the telescopic sealing tube 5. When the hard impurities come into contact with the annular scraper 14, the elasticity of the spring 15 drives the annular scraper 14 in the annular groove 12 to slide up and down on the outer surface of the sleeve 13, thereby cleaning the hard impurities on the outer wall of the telescopic sealing tube 5, preventing the hard impurities from moving in the fluid and causing friction on the outer wall of the pipe, thereby increasing the service life of the pipe and reducing production costs.

[0034] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A straight-through retractable thermal extraction sleeve head, characterized in that: include: The sleeve head (4) has a fixed sealing seat (3) threadedly connected to its inner surface. The inner surface of the fixed sealing seat (3) is provided with a telescopic sealing tube (5). The outer end of the telescopic sealing tube (5) is provided with a limit step (7). The lower end of the sleeve head (4) is threaded with an elastic scraping assembly. The elastic scraping assembly includes a connecting disc (11), an annular groove (12) is provided on the inner surface of the connecting disc (11), a sleeve post (13) is fixedly installed on the inner surface of the annular groove (12), an annular scraper (14) is sleeved on the outer surface of the sleeve post (13), and a spring (15) is sleeved at the upper and lower connecting ends of the annular scraper (14) and the sleeve post (13).

2. The straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: The telescopic sealing tube (5) is provided with an upper coupling (1) and a lower coupling (6) at its upper and lower ends. The inner surfaces of the upper coupling (1) and the lower coupling (6) are provided with internal threads (9), and the outer surfaces of the upper and lower ends of the telescopic sealing tube (5) are provided with external threads (8). The telescopic sealing tube (5) is threadedly connected to the inner threads (9) on the inner surfaces of the upper coupling (1) and the lower coupling (6) through the external threads (8).

3. The straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: The side surface of the sleeve head (4) is provided with several sets of threaded holes (20), and the inner surface of the threaded holes (20) is threaded with a stop screw (2), which is threaded to the fixed sealing seat (3).

4. The straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: The annular scraper (14) and the sleeve (13) are slidably connected by a spring (15), and the inner wall of the annular scraper (14) is in contact with the outer wall of the telescopic sealing tube (5).

5. A straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: The sleeve head (4) has an overflow pipe (10) threaded on both sides of its center end, and an overflow hole is provided on the lower surface of the overflow pipe (10).

6. A straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: The lower inner wall of the sleeve head (4) is fixedly equipped with several sets of mounting bosses (17), and the outer wall of the connecting plate (11) is provided with several sets of mounting slots (16), which are engaged with the mounting bosses (17).

7. A straight-through retractable thermal extraction sleeve head according to claim 1, characterized in that: A sealing groove (18) is provided at the connection between the sleeve head (4) and the telescopic sealing tube (5), and a sealing strip (19) is provided on the inner surface of the sealing groove (18).

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