A type of containment isolator

Abstract

This utility model relates to the field of oil extraction, specifically to a sealing and isolating device; it includes an upper connecting unit, a desealing unit, a sealing unit, a lower connecting unit, and an anti-backflow unit; one end of the desealing unit is connected to the upper connecting unit, and the other end is connected to the sealing unit; the sealing unit is connected to both the lower connecting unit and the anti-backflow unit; and the lower connecting unit is connected to the anti-backflow unit. This device has a reasonable structure and is easy to operate. It greatly simplifies the construction process for renovating old wells in oil fields, reduces labor intensity, lowers operational risks, and reduces construction costs.

Description

Technical Field

[0001] This utility model relates to the field of oil extraction, specifically to a containment isolator. Background Technology

[0002] In the middle and late stages of oilfield development, oil wells often face the problem of rising water cut or water flooding. There are three main reasons why old oil wells are shut down for a long time due to high water cut: First, water flooding is caused by corrosion and perforation of the oil layer casing; second, water flooding is caused by the formation of a water head cone in high-pressure water injection wells; and third, water flooding is caused by the mutual flow of high-pressure water layers near the oil layer and the oil layer.

[0003] For the aforementioned well, leak detection using packers ruled out the possibility of casing corrosion and perforation. The conventional approach is to first perforate the engineering hole in the high-pressure water layer, then chemically seal it with cement slurry, and finally drill out the cement plug to resume oil production. However, in this well, the producing oil layer is above and adjacent to the high-pressure water layer, making the conventional method risky and prone to clogging the oil layer; even attempting to plug the high-pressure water layer may fail. Therefore, it is necessary to first run tools to isolate the oil layer from the high-pressure water layer before sealing the high-pressure water layer. In China, cement retainers are commonly used for packing and cementing operations, but traditional cement retainers have technical problems: milling-type retainers require mid-way setting, have long milling times, are difficult to return metal debris, and are costly; conventional types lack anti-backflow valves, preventing immediate tripping after cementing, posing a safety risk; and require setting before re-insertion, involving two tubing runs, making the process complex.

[0004] To address these needs, cement retainers are commonly used domestically for sealing and cementing operations. Cement retainers have been in use for many years, with traditional types mostly being drillable / millable or re-insertion tubing types (current technology). Firstly, millable retainers are prone to mid-milling during milling, resulting in lengthy milling times, heavy metal debris that is difficult to remove, and high operating costs. Secondly, conventional cement retainers lack anti-backflow valves, preventing immediate drilling after cementing and posing safety risks. Thirdly, they require sealing before re-insertion, involving two tubing runs, making the process complex. Utility Model Content

[0005] The purpose of this utility model is to solve the problems of existing sealing isolators in the background art, such as the inability of existing tools to unseal, the need for drilling and grinding to restore the wellbore, and the inability to close the injection valve or the low reliability of the injection valve closure after injection.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This utility model proposes a sealing and isolating device, including an upper connection unit, an unsealing unit, a sealing unit, a lower connection unit, and an anti-backflow unit;

[0008] One end of the unsealing unit is connected to the upper connecting unit, and the other end is connected to the sealing unit. The sealing unit is connected to the lower connecting unit and the anti-backflow unit respectively. The lower connecting unit is connected to the anti-backflow unit.

[0009] As a further improvement, the upper connection unit includes an upper connector, a tube, a ball seat, and a multi-functional valve;

[0010] The upper connector is threadedly connected to the insertion tube, wherein the insertion tube is mounted on the ball seat, the ball seat is connected to the multi-functional valve and fixed by a shear pin, and the multi-functional valve is also equipped with a positioning spring.

[0011] As a further improvement, the unsealing unit includes an unsealing sleeve, a release sleeve, a lock seat connector, a lock block, a sealing sleeve, and a first upper cone;

[0012] The unsealing sleeve and the release sleeve are threadedly connected and fixed to the lock seat connector by a pin;

[0013] One end of the lock seat connector is connected to the sealing sleeve, and the other end is connected to the first upper tapered thread;

[0014] The lock block is installed on the lock seat connector.

[0015] As a further improvement, a sealing ring is also included, which is disposed between the lock seat connector and the insertion tube.

[0016] As a further improvement, the sealing unit includes a central tube, slips, rubber sleeve assembly, rubber sleeve seat, steel sleeve, lower central tube, and locking sleeve;

[0017] The central tube is equipped with a slip sleeve and a rubber sleeve assembly;

[0018] One end of the rubber sleeve seat is connected to the rubber sleeve assembly, and the other end is connected to the lower central pipe thread;

[0019] The rubber sleeve seat is also threadedly connected to the locking sleeve, and the locking sleeve is also threadedly connected to the locking sleeve.

[0020] As a further improvement, the slip sleeve includes a slip, a second upper cone, and a clamp spring;

[0021] The rubber sleeve assembly includes a side rubber sleeve, a spacer ring, and a middle rubber sleeve.

[0022] As a further improvement, the lower connection unit includes a connector, a valve sleeve, a guide shoe, and a locking spring seat;

[0023] One end of the valve sleeve is connected to the connecting body, and the other end is connected to the guide shoe;

[0024] One end of the locking spring seat is connected to the lower central tube, and the other end is threaded to the connecting body;

[0025] A locking ring is installed on the locking spring seat.

[0026] As a further improvement, the anti-backflow unit includes a first float hoop and a second float hoop, the first float hoop being threadedly connected to the valve sleeve, and the second float hoop being threadedly connected to the guide shoe.

[0027] As a further improvement, the first float includes a first valve core, a first valve seat, a first valve spring, and a first valve plate;

[0028] Both the first valve seat and the first valve plate are threadedly connected to the valve sleeve, wherein the first valve seat contains a first valve core and a first valve spring.

[0029] As a further improvement, the second float includes a second valve core, a second valve seat, a second valve spring, and a spring seat; the second valve seat and the spring seat are both threadedly connected to the guide shoe, wherein the second valve seat contains the second valve core and the second valve spring.

[0030] Compared with the prior art, this utility model achieves the following technical effects:

[0031] This invention combines an upper connecting unit, an unsealing unit, a sealing unit, a lower connecting unit, and an anti-backflow unit, with each unit working closely together. The device features a primary piston chamber formed by the rubber sleeve seat and the lower central tube, and a secondary piston chamber formed by the steel sleeve and the locking spring seat. These two stages of pistons push the rubber sleeve, providing higher thrust, resulting in better anchoring of the slips, and compression of the rubber sleeve with less pressure, thus increasing reliability. This effectively reduces wellhead injection pressure, decreases the pressure requirements of surface pressurization equipment, and lowers costs.

[0032] The anti-backflow unit in this device includes a first float and a second float. The two-stage design effectively prevents cement slurry backflow caused by the failure of a single float, making the structure safer and more reliable. Furthermore, the device has a reasonable structure and is easy to operate. It greatly simplifies the construction process for renovating old wells in oil fields, reduces labor intensity, lowers operational risks, and reduces construction costs. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0034] Reference numerals: 1. Upper connector; 2. Insert tube; 3. Unsealing sleeve; 4. Sealing sleeve; 5. Pin; 6. Sealing ring; 7. Lock seat connector; 8. Lock block; 9. Release sleeve; 10. Central tube; 11. First upper cone; 12. Slip; 13. Hoop spring; 14. Slip sleeve; 15. Second upper cone; 16. Side rubber sleeve; 17. Spacer ring; 18. Middle rubber sleeve; 19. Rubber sleeve seat; 20. Lower central tube; 21. 21. Steel sleeve; 22. Locking ring; 23. Locking spring seat; 24. Lock sleeve; 25. Locking device; 26. Connector; 27. Ball seat; 28. Multifunctional valve; 29. ​​Shear pin; 30. Positioning spring; 31. First valve core; 32. First valve seat; 33. First valve spring; 34. Valve sleeve; 35. First valve plate; 36. Guide shoe; 37. Second valve core; 38. Second valve seat; 39. Second valve spring; 40. Spring seat. Detailed Implementation

[0035] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0036] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0037] See Figure 1 This embodiment proposes a sealing isolator, including an upper connection unit, a desealing unit, a sealing unit, a lower connection unit, and an anti-backflow unit; one end of the desealing unit is connected to the upper connection unit, and the other end is connected to the sealing unit; the sealing unit is connected to the lower connection unit and the anti-backflow unit respectively; and the lower connection unit is connected to the anti-backflow unit.

[0038] The upper connection unit of this embodiment includes an upper connector 1, a tubing 2, a ball seat 27, and a multi-functional valve 28. The upper connector 1 is threadedly connected to the tubing 2. The ball seat 27 is installed on the tubing 2, and the ball seat 27 is fixed to the multi-functional valve 28 by shear pins 29. A positioning spring 30 is installed on the multi-functional valve 28. This embodiment enables clean well completion. After setting, the pressure is increased to shear the shear pins 29, causing the multi-functional valve 28 to descend and open the cement injection channel. Simultaneously, the tubing 2 disengages from the multi-functional integrated sealing isolator, and the ball seat 27 and the ball are carried out of the ground along with the tubing 2. This prevents the ball seat 27 from falling into the multi-functional integrated sealing isolator and causing injection throttling, thus achieving clean well completion.

[0039] The unsealing unit of this embodiment includes an unsealing sleeve 3, a release sleeve 9, a lock seat connector 7, a lock block 8, a sealing sleeve 4, and a first upper cone 11; wherein the unsealing sleeve 3 is threadedly connected to the release sleeve 9, and the unsealing sleeve 3 is fixed to the lock seat connector 7 by a pin 5, a sealing ring 6 is installed on the lock seat connector 7, the sealing sleeve 4 is threadedly connected to the lock seat connector 7, the lock block 8 is installed on the lock seat connector 7, and the lock seat connector 7 is threadedly connected to the first upper cone 11.

[0040] The sealing unit in this embodiment includes a central tube 10, a slip 12, a rubber sleeve assembly, a rubber sleeve seat 19, a steel sleeve 21, a lower central tube 20, and a locking sleeve 24. A slip sleeve 14 is installed on the central tube 10, and a slip 12 and a second upper cone 15 are installed inside the slip sleeve 14. A clamp spring 13 is installed on the slip 12. A side rubber sleeve 16, a spacer ring 17, and a middle rubber sleeve 18 are installed on the central tube 10. The rubber sleeve seat 19 is threaded to the steel sleeve 21, and the steel sleeve 21 is threaded to the locking sleeve 24. The locking sleeve 24 is fixed to the connecting body 26 by a pin 5. This embodiment adopts a two-stage setting piston design with low setting pressure. The first-stage piston chamber consists of the rubber sleeve seat 19 and the lower central tube 20, and the second-stage piston chamber consists of the steel sleeve 21 and the locking spring seat 23. The two-stage pistons can jointly push the slips 12 and the rubber sleeve seat 19, providing higher thrust, which makes the slips 12 better anchored, and the rubber sleeve is compressed with less pressure, resulting in higher reliability. This effectively reduces the wellhead injection pressure, reduces the pressure requirements of the surface pressurization equipment, and lowers costs.

[0041] The lower connection unit of this embodiment includes a connector 26, a valve sleeve 34, a guide shoe 36, and a locking spring seat 23; wherein the connector 26, the valve sleeve 34, and the guide shoe 36 are connected in sequence by threads, wherein the lower central tube 20 is threadedly connected to the locking spring seat 23, a locking ring 22 is installed on the locking spring seat 23, and the locking spring seat 23 is threadedly connected to the connector 26.

[0042] This embodiment also includes a locking device 25, which is used to connect and lock the relative positions of the lock sleeve 24 and the connector 26.

[0043] The anti-backflow unit of this embodiment includes a first float hoop and a second float hoop, with a dual-stage injection channel float hoop design that is safe and reliable. The first valve seat 32 and the first valve plate 35 are fixed to the valve sleeve 34 by threads, and the first valve spring 33 and the first valve core 31 are installed inside to form the first float hoop. The second valve core 37 and the spring seat 40 are fixed to the guide shoe 36 by threads, and the second valve seat 38 and the second valve spring 39 are installed inside to form the second float hoop. After the formation sealing is completed, if the float hoop fails, it will cause cement slurry to flow back. The two-stage float hoop design in this embodiment can effectively prevent cement slurry backflow caused by the failure of a single-stage float hoop, making the structure safer and more reliable.

[0044] The usage process of this embodiment is as follows:

[0045] Step 1, Setting: The device is lowered into the well along with the tubing. The pressurized fluid from the tubing enters the piston chamber of the two-stage piston of the device through the inlet port on the insertion pipe 2, increasing the pressure and shearing the setting pin 5. The piston drives the rubber sleeve seat 19, steel sleeve 21, and locking sleeve 24 to move upward, compressing the rubber sleeve and supporting slip 12, thus setting the seal. At the same time, the locking ring 22 and locking sleeve 24 are locked to prevent unlocking.

[0046] Step 2, Release: Continue to increase the pressure, cut off the release pin 5, move the multi-function valve 28 downwards, and release; at the same time, open the injection channel;

[0047] Step 3, Cementing: The tubing string does not need to be moved; the cement is directly injected into the formation through the tubing.

[0048] Step 4: Lifting the tubing to seal the wellbore: After the formation is squeezed, the dual-stage valve core closes automatically under the action of the spring, and the tubing is lifted directly to squeeze the wellbore.

[0049] Step 5, Unsealing: Lower the special unsealing and retrieval tool, lift the tubing string to make the unsealing sleeve 3 move upward, pin 5 cuts the unsealing sleeve 3 and continues to move upward to release the locking block 8, the upper cone moves upward and separates from the slip 12, the two ends of the slip 12 lose support, so the slip 12, the side rubber sleeve 16, and the middle rubber sleeve 18 return to their original state, the plugged tubing string is unsealed and pulled out of the well.

[0050] This device adopts an integrated structural design, realizing functions such as setting, releasing, and squeezing in one go. It can complete squeezing without other drilling operations, reducing manpower and material consumption and simplifying construction.

[0051] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0052] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. 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.

[0054] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A containment isolator, characterized in that, It includes an upper connection unit, an unsealing unit, a sealing unit, a lower connection unit, and an anti-backflow unit; One end of the unsealing unit is connected to the upper connecting unit, and the other end is connected to the sealing unit. The sealing unit is connected to the lower connecting unit and the anti-backflow unit respectively. The lower connecting unit is connected to the anti-backflow unit. The unsealing unit includes an unsealing sleeve, a release sleeve, a lock seat connector, a lock block, a sealing sleeve, and a first upper cone; The unsealing sleeve and the release sleeve are threadedly connected and fixed to the lock seat connector by a pin; One end of the lock seat connector is connected to the sealing sleeve, and the other end is connected to the first upper tapered thread; The lock block is installed on the lock seat connector; The anti-backflow unit includes a first float hoop and a second float hoop. The first float hoop is threadedly connected to the valve sleeve, and the second float hoop is threadedly connected to the guide shoe.

2. The containment isolator according to claim 1, characterized in that, The upper connection unit includes an upper connector, a tube, a ball seat, and a multi-functional valve; The upper connector is threadedly connected to the insertion tube, wherein the insertion tube is mounted on the ball seat, the ball seat is connected to the multi-functional valve and fixed by a shear pin, and the multi-functional valve is also equipped with a positioning spring.

3. The containment isolator according to claim 1, characterized in that, It also includes a sealing ring, which is located between the lock seat connector and the insertion tube.

4. The containment isolator according to claim 1, characterized in that, The sealing unit includes a central tube, slips, rubber sleeve assembly, rubber sleeve seat, steel sleeve, lower central tube, and locking sleeve; The central tube is equipped with a slip sleeve and a rubber sleeve assembly; One end of the rubber sleeve seat is connected to the rubber sleeve assembly, and the other end is connected to the lower central pipe thread; The rubber sleeve seat is also threadedly connected to the locking sleeve, and the locking sleeve is also threadedly connected to the locking sleeve.

5. A containment isolator according to claim 4, characterized in that, The slip sleeve includes a slip, a second upper cone, and a clamp spring; The rubber sleeve assembly includes a side rubber sleeve, a spacer ring, and a middle rubber sleeve.

6. The containment isolator according to claim 1, characterized in that, The lower connection unit includes a connector, a valve sleeve, a guide shoe, and a locking spring seat; One end of the valve sleeve is connected to the connecting body, and the other end is connected to the guide shoe; One end of the locking spring seat is connected to the lower central tube, and the other end is threaded to the connecting body; A locking ring is installed on the locking spring seat.

7. The containment isolator according to claim 1, characterized in that, The first float includes a first valve core, a first valve seat, a first valve spring, and a first valve plate; Both the first valve seat and the first valve plate are threadedly connected to the valve sleeve, wherein the first valve seat contains a first valve core and a first valve spring.

8. The containment isolator according to claim 1, characterized in that, The second float includes a second valve core, a second valve seat, a second valve spring, and a spring seat; The second valve seat and the spring seat are both threadedly connected to the guide shoe, wherein the second valve seat contains a second valve core and a second valve spring.

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