A hanging packer for sidetracking wells and a method for operating the same

Abstract

This invention relates to a suspended packer for sidetracking wells and its construction method. It includes hydraulic cylinders and an anchoring mechanism. Two or more hydraulic cylinders are connected below the upper connector of the device. The upper part of the central tube in the initial working hydraulic cylinders does not have a sealing ring. The hydraulic cylinders are connected to each other through a central tube connector with a fluid flow hole and an outer cylinder connector. Below the central tube connector connected to the central tube of the lower hydraulic cylinder, a locking cylinder connects to a top cylinder and a large rubber plug. A small rubber plug can be inserted into the large rubber plug. The top cylinder is installed in the inner cavity of the lower part of the locking cylinder, and the locking block is sealed in the locking block limiting groove in the hanging cylinder outside the top cylinder. This invention is applicable to various sidetracking wells and oil and water wells requiring tailpipe suspension. The outer connecting cylinder can connect to the large-size completion casing in the sidetracking well, achieving the goal of matching its inner diameter with the inner diameter of the large-size completion casing in the sidetracking well, providing convenient application conditions for the implementation of subsequent oil production processes.

Description

Technical Field

[0001] This invention relates to the field of well completion technology for sidetracking wells in the petroleum industry, specifically to a suspended packer for sidetracking wells and its construction method. Background Technology

[0002] Sidetracking packers are a core tool commonly used in current sidetracking technology. However, with the large-scale application of sidetracking technology, various processes have increasingly higher requirements for the inner diameter after sidetracking completion and for safe sidetracking operations. Currently, commonly used mechanical and expandable packers struggle to simultaneously meet these requirements. While the mechanical packers commonly used in production sites employ a process of suspension followed by release and cementing, resulting in a higher safety factor, their structure and working principle limit the number of slips that need to be pushed uphill by a hydraulic cylinder. This leads to the packer's single-sidewall structure typically having two or more layers, making it difficult to achieve the same inner diameter as the lower, larger-diameter completion casing. For example, in the 51 / 2 wellbore, if a mechanical packer is used to suspend a 114.3mm straight-connected casing for completion, the packer's suspension position is generally at the reduction in diameter of the completion string. For instance: The tailpipe suspension packer disclosed in application publication number CN107956442A and the suspension packer discussed in the article "Research and Application of a New Type of Suspension Packer" both belong to this type.

[0003] In addition to the above, another commonly used type is the expandable suspension packer developed using the principle of expansion tubes. This type of suspension packer uses a combination of metal rings and rubber rings, and uses the expansion tube to suspend and seal the lower casing. After expansion, it can provide an inner diameter equal to or greater than that of the lower tailpipe. However, due to the limitations of its working principle, its suspension construction must begin after cementing; otherwise, cementing cannot be carried out. Because the expansion tube suspension and seal are integrated, there is no circulation channel for cement slurry after suspension, thus posing a significant safety hazard. Once the tailpipe completion string leaks, the pressure inside the pipe cannot rise to the starting pressure of the expansion tube expansion, and the inserted string cannot achieve technical separation from the tailpipe, easily leading to a downhole accident where the casing cement slurry is filled and solidified, commonly known as "flagpole insertion." The following tools are mentioned: The suspended packer described in the application publication number CN102979472A, titled "Expandable Suspended Packer," and the article "Research and Application of Large-Diameter Tailpipe Completion Technology in Side-Drilling Wells" belongs to this type.

[0004] In summary, the market urgently needs a tailpipe suspension packer with low safety risk and a large inner diameter. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a suspended packer for sidetracking wells and its construction method, solving the issue that existing large-diameter expansion suspended packers for sidetracking wells cannot perform the mounting, release, and packing processes in separate steps. It meets the requirements for safe sidetracking well construction, facilitates cementing operations, and avoids downhole cementing accidents. It also improves construction efficiency, ensures safe production, and reduces production costs.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: A side-drilling suspended packer includes a hydraulic cylinder and an anchoring mechanism, wherein: The hydraulic cylinders are equipped with two or more hydraulic cylinders and connected to the lower part of the upper connector of the device. The upper part of the central tube of the hydraulic cylinder in the early stage is not equipped with a sealing ring. The hydraulic cylinders are connected to the outer cylinder connector through the central tube connector with the fluid flow hole. The central tube connector in the upper hydraulic cylinder is connected to the upper connector of the device. The upper outer cylinder and the outer cylinder of the lower hydraulic cylinder with the outer cylinder inlet hole are connected through the outer cylinder connector. The bottom of the central tube connecting cylinder, which is connected to the central tube of the lower hydraulic cylinder, is connected to the top cylinder and the large rubber plug via a locking cylinder. Small rubber plugs can be inserted into the large rubber plug. Below the expansion cylinder with a mud flow channel, which is connected to the outer cylinder connector of the lower hydraulic cylinder, is an anchoring mechanism consisting of an expansion sleeve, slips, an expansion sealing cylinder with a rubber sleeve, and a hanging cylinder connected in sequence, as well as an outer connecting cylinder that connects to the completion casing in the side drilling well. The top cylinder is installed in the inner cavity of the lower part of the lock cylinder and seals the lock block in the lock block limiting groove in the hanging cylinder outside the top cylinder.

[0007] Preferably, the central tube is connected to the central tube connector, the central tube connecting sleeve is connected to the central tube connector, the central tube connecting sleeve is connected to the lock sleeve, and the lock sleeve is connected to the large rubber stopper by shear pins and sealed by sealing rings; the central tube is connected to the central tube connector by threads; the upper inner cavity of the upper outer cylinder is a pressure relief cavity, and the inner circle of the pressure relief cavity is larger than the inner circle of the lower inner cavity.

[0008] Preferably, a slide cylinder is also connected in the inner cavity of the central tube connector that is connected to the upper connector of the device, and the hydraulic cylinder connected to the slide cylinder is the hydraulic cylinder for later operation; the slide cylinders in the hydraulic cylinders for later operation are all connected to the central tube connector by shear pins, and the sealing ring in the slide cylinder is located above the fluid flow hole of the connector, and the hydraulic cylinder for later operation is connected to the lower part of the upper connector of the device; anti-loosening pins are also provided between the threaded connection section of the upper connector of the device and the central tube connector, and between the threaded connection section of the central tube and the central tube connector.

[0009] Preferably, the anchoring mechanism further includes a slip cylinder, which is a cylindrical structure with a slip assembly groove in the cylinder wall that matches the shape of the slip, and a radial flow groove in the cylinder wall below the slip assembly groove. The two ends of the slip cylinder are respectively machined with threads that can connect with the expansion sleeve and the expansion sealing cylinder. The slip installed in the slip assembly groove is connected to the expansion cylinder by a shear pin.

[0010] Preferably, the expansion sealing cylinder is a non-uniform diameter cylindrical body, and a rubber tube of the same height as the outer circle is vulcanized in the diameter reduction groove in the middle of the outer circle of the cylinder. The two ends of the expansion sealing cylinder are respectively machined with threads for connection with the slip cylinder and the hanging cylinder; the bodies of the expansion sealing cylinder and the expansion sleeve are both made of metal expansion tube material.

[0011] Preferably, the lock cylinder has a non-uniform diameter cylindrical structure and has one or more lock block through holes and shear pin holes machined in the cylinder body. The large inner diameter section below the shear pin hole is the lock block pushing cavity, and the lock block through hole is machined in the lock block pushing cavity. The lower part of the lock cylinder is a rubber plug insertion body that matches the upper inner cavity of the large rubber plug, and a sealing ring groove is machined on the outer wall of the rubber plug insertion body. The lower part of the lock block pushing cavity has a top cylinder sliding cavity that matches the lower outer circle of the top cylinder. The internal thread provided on the upper inner circle of the lock cylinder can be threaded to the central tube connecting cylinder and connected to the top cylinder through shear pins in the inner cavity with shear pin holes.

[0012] Preferably, the outer circle of the top cylinder is a non-uniform diameter outer circle, and a shear pin connecting section, a lock block release section, a lock block pushing section, and a lock cylinder sliding section are machined from top to bottom on the outer circle. The shear pin connecting section is connected to the lock cylinder by shear pins. The outer diameter of the lock block pushing section is larger than that of the lock block release section and has chamfers at both ends. The outer diameter of the lock block pushing section matches the inner diameter of the internal thread section in the upper inner circle of the lock cylinder, so that the top cylinder can be placed in the inner cavity of the lock cylinder. The lock cylinder sliding section can be inserted into the top cylinder sliding cavity in the lock cylinder.

[0013] Preferably, the locking block is an arc-shaped block with a linear cutting groove machined on its inner wall along the axial direction. A leaf spring mounting groove is machined in the clamping wall of the linear cutting groove. Both ends of the leaf spring mounting groove are chamfered at their inward exit points to facilitate the installation of the leaf spring. A leaf spring is installed in the leaf spring mounting groove.

[0014] Preferably, the large rubber stopper comprises a rubber stopper rigid body and a large rubber stopper sealing body. The rubber stopper rigid body is a non-uniform diameter cylindrical body, and its inner cavity, from top to bottom, consists of a locking cylinder mating cavity, a small rubber stopper insertion cavity, and a small rubber stopper holding cavity. The outer diameter of the rubber stopper rigid body is provided with one or more sealing ring grooves and shear pin holes, and the outer diameter of the large rubber stopper sealing body is vulcanized. The outer diameter of the large rubber stopper sealing body is provided with three or more rubber wings. The outer diameter of the large rubber stopper sealing body is larger than the inner diameter of the outer connecting cylinder.

[0015] Preferably, the upper part of the rigid body of the small rubber stopper is a solid structure, and the outer circle of the upper part of the rigid body is provided with an external thread section that can be connected to the retaining ring, a rubber stopper mounting section, and a rubber stopper limiting step; a small rubber stopper fixing pawl with a pawl at the lower end is provided below the rubber stopper limiting step; a small rubber stopper sealing body is vulcanized outside the rubber stopper mounting section on the outer circle of the rigid body of the small rubber stopper, and the outer circle of the small rubber stopper sealing body is provided with three or more rubber wings; the outer circles of the small rubber stopper sealing body and the small rubber stopper fixing pawl are both larger than the inner circles of the small rubber stopper insertion cavity and the small rubber stopper holding cavity in the large rubber stopper.

[0016] The construction method for the aforementioned side-drilling suspended packer includes the following steps: A. Deploy the suspended packer downhole and connect it to the completion casing in the side-drilled well; B. The packer is mounted downhole; C. The suspended packer is released downhole; D. Seal the annulus of the oil jacket by using a suspended packer.

[0017] Compared with the prior art, the present invention has the following significant advantages: This invention is applicable to various side-drilled wells and oil and water wells that require tailpipe suspension.

[0018] 1. The outer connecting cylinder in this suspended packer can be connected to the large-sized completion casing in side-drilling wells. In other words, the inner diameter of this suspended packer is larger than the inner diameter of existing mechanical and hydraulic suspended packers, providing a larger inner diameter for the implementation of processes after side-drilling completion and broadening the application range of oil production technology.

[0019] 2. The structure and working principle of this suspended packer enable it to perform three functions downhole: suspension, release, and packing, and these functions can be executed in stages. Compared with existing expandable tubing-type suspended packers that perform all three functions simultaneously, this device is safer and more reliable, minimizing the risk of the cementing string solidifying downhole due to the inability to release it in time.

[0020] 3. The device of this invention combines the advantages of mechanical, hydraulic and expansion tube type suspension packers in terms of working principle. While ensuring that the safety factor of the tool is not reduced, it achieves the goal of making the inner diameter of the tool consistent with the inner diameter of the large-size completion casing in side-drilling, providing convenient application conditions for the implementation of subsequent oil production technology.

[0021] 4. The device of this invention is delivered downhole by a feed string. Once the suspended packer has completed the sealing of the annulus, the feed string is used as the cementing string. Therefore, when cementing risks occur downhole, the suspended packer can be promptly released from the well casing and retrieved from the well along with the feed string. This effectively avoids downhole cementing accidents, improves construction efficiency, ensures safe production, and significantly reduces production costs.

[0022] In summary, the device of the present invention has excellent performance and can achieve significant economic and social benefits, with huge potential for promotion. Attached Figure Description

[0023] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of the present invention.

[0024] Figure 2 yes Figure 1 A schematic diagram of the structure of the middle slip cylinder 16.

[0025] Figure 3 yes Figure 1 A schematic diagram of the structure of the expansion sealing cylinder 17.

[0026] Figure 4 yes Figure 1 A schematic diagram of the structure of the central locking cylinder 18.

[0027] Figure 5 yes Figure 1 A schematic diagram of the structure of the central top cylinder 19.

[0028] Figure 6 yes Figure 1 A schematic diagram of the structure of the middle hanging cylinder 20.

[0029] Figure 7 yes Figure 1 The front view, left view and top view of the central locking block 21.

[0030] Figure 8 yes Figure 1 A schematic diagram of the structure of the large rubber stopper 23.

[0031] Figure 9 yes Figure 1 A schematic diagram of the structure of the small and medium-sized rubber stopper 10.

[0032] In the picture: The device includes: upper connector 1, upper outer cylinder 2, central tube connector 3, sliding cylinder 4, outer cylinder connector 5, central tube 6, outer cylinder 7, connector liquid flow hole 8, and outer cylinder liquid flow hole 9. Small rubber stopper 10, small rubber stopper sealing body 10-1, rubber stopper limiting step 10-2; small rubber stopper fixing pawl 10-3, pawl anti-disengagement hook 10-4; 11. Retaining ring, 12. Central tube connecting cylinder, 13. Expansion cylinder, 14. Expansion retaining sleeve, 15. 16 slip cylinder, 16-1 slip assembly groove, 16-2 flow groove; Expansion sealing cylinder 17, diameter reduction groove 17-1, rubber sleeve 17-2; Lock cylinder 18, top cylinder sliding cavity 18-1, rubber plug connector 18-2, lock block pushing cavity 18-3, lock block through hole 18-4; Top cylinder 19, shear pin connecting section 19-1, lock block release section 19-2, lock block pushing section 19-3, lock cylinder sliding section 19-4; Hanging cylinder 20, locking block limiting groove 20-1; Lock block 21, leaf spring mounting groove 21-1, chamfer 21-2, linear cutting groove 21-3; External connecting cylinder 22; Large rubber stopper 23, rubber stopper rigid body 23-1, large rubber stopper sealing body 23-2. Detailed Implementation

[0033] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this invention. The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0034] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0035] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0036] See Figures 1-9 A side-drilling suspended packer includes a hydraulic cylinder and an anchoring mechanism, wherein: A hydraulic cylinder of level two or above is installed and connected to the lower part of the upper connector 1 of the device. The upper part of the central tube 6 of the hydraulic cylinder in the early stage is not equipped with a sealing ring. The hydraulic cylinders are connected to the outer cylinder connector 5 through the central tube connector 3 with the connecting head liquid flow hole 8. The central tube connector 3 of the upper hydraulic cylinder is connected to the upper connector 1 of the device. The upper outer cylinder 2 and the outer cylinder 7 of the lower hydraulic cylinder with the outer cylinder liquid inlet hole 9 are connected through the outer cylinder connector 5. The bottom of the central tube connecting cylinder 12, which is connected to the central tube 6 of the lower hydraulic cylinder, is connected to the top cylinder 19 and the large rubber plug 23 via the locking cylinder 18. The small rubber plug 10 can be inserted into the large rubber plug 23. Below the expansion cylinder 13, which is connected to the outer cylinder connector 5 of the lower hydraulic cylinder and has a mud flow channel, is an anchoring mechanism consisting of an expansion sleeve 14, a slip 15, an expansion sealing cylinder 17 with a rubber sleeve 17-2, and a hanging cylinder 20 connected in sequence, as well as an outer connecting cylinder 22 that is connected to the completion casing in the side drilling well. The top cylinder 19 is installed in the inner cavity of the lower part of the lock cylinder 18 and seals the lock block 21 in the lock block limiting groove 20-1 in the hanging cylinder 20 outside the top cylinder 19.

[0037] All hydraulic cylinders, central tube connecting sleeve 12, lock sleeve 18, and top sleeve 19 connected below the connector 1 on the device can be pulled out from the suspended packer after cementing. This avoids accidents such as "flagpole insertion" or "enema injection" during downhole cementing and can significantly reduce construction costs.

[0038] The hydraulic cylinder in this invention is mainly composed of a central tube 6, a central tube connector 3 with a connector fluid flow hole 8, an outer cylinder connector 5, and an outer cylinder 7 with an outer cylinder fluid flow hole 9. The central tube connector 3 and the outer cylinder connector 5 are connected between the central tube 6 and the outer cylinder 2.

[0039] The outer connecting sleeve 22 in this invention can be connected to the large-size completion casing in sidetracking wells, which means that the inner diameter of this invention is consistent with the inner diameter of the casing in sidetracking wells. This greatly facilitates the insertion of large-size tools from this suspended packer during the implementation of various oil production processes.

[0040] Using this suspended packer, the steps of setting up, releasing, and packing can be achieved downhole: The invention relates to the installation and suspension of the device underground: The invention is connected to the lower end of the feed string via the upper connector 1 of the device. The invention is then fed downhole and connected to the large-diameter completion casing in the side-drilled well via the outer connecting sleeve 22. The feed string is used as a cementing string after the annulus is sealed by the suspension packer.

[0041] Hydraulic pressure is applied on the ground to increase the pressure of this invention. High-pressure liquid enters all hydraulic cylinders between the central tube 6 and the central tube connecting cylinder 12 through the upper connector 1 of the device. Since the upper part of the central tube 6 of the hydraulic cylinders used in the early stage has no sealing ring and can be filled with liquid, the hydraulic cylinders used in the early stage start to work. The expansion cylinder 13 connected to the lower hydraulic cylinder moves relative to the central tube connecting cylinder 12. The working hydraulic cylinder drives the central tube connecting cylinder 12, the locking cylinder 18 and the top cylinder 19 to move upward. The expansion cylinder 13 expands the diameter of the expansion sleeve 14. At the same time as the diameter is expanded, the slip 15 is pushed out and locked on the completion casing in the side-drilled well, completing the mounting of the device of this invention downhole.

[0042] The device of this invention is released underground: As the hydraulic pressure continues to increase on the ground, the top cylinder 19 slides up and down within the lower inner cavity of the locking cylinder 18, disconnecting from the locking cylinder 18 and the large rubber plug 23, thus releasing and unlocking the locking block 21. At this point, the insertion string can be lifted a certain distance on the ground to verify whether the release was successful.

[0043] The device of this invention provides sealing in the well: After the invention was successfully tested downhole, the surface pressure was increased to open the cementing float shoe installed at the lower end of the completion casing string for cementing. After the cement slurry is injected, the small rubber plug 10 and the large rubber plug 23 are stacked together and then pushed down to the bottom of the well completion casing string from the surface to replace the cement slurry. The cementing float shoe installed at the bottom of the well completion casing string is then closed. Depressurize on the ground, lower the insertion column so that the expansion cylinder 13 contacts the expansion sealing cylinder 17 equipped with rubber cylinder 17-2, and lower the insertion column to the preset tonnage so that the hydraulic cylinder above the central pipe connecting cylinder 12 is reset. Continue pressurizing to the predetermined value on the ground. All hydraulic cylinders work simultaneously to fully expand the diameter of the expansion sealing cylinder 17 in the anchoring mechanism, allowing the rubber sleeve 17-2 inside to seal the annulus of the oil sleeve. Then, depressurize the hydraulic cylinders on the ground. Raise the feed string and perform a large-volume backwash to remove excess cement slurry. Remove the feed string and the hydraulic cylinders, central tube connecting cylinder 12, locking cylinder 18, and top cylinder 19 connected below the upper connector 1 of the device. The construction is then complete. In the side-drilled well, only the anchoring mechanism located on the outer layer of this suspended packer, the outer connecting cylinder 22, and the large rubber plug 23 and small rubber plug 10 located at the bottom of the completion casing string remain.

[0044] Based on the above embodiment one, the present invention also has the following embodiments: In a preferred embodiment: the central tube 6 and the central tube connector 3, the central tube connecting cylinder 12 and the central tube connector 3, the central tube connecting cylinder 12 and the locking cylinder 18, and the locking cylinder 18 and the large rubber plug 23 are all connected by shear pins and sealed with sealing rings; the central tube 6 and the central tube connector 3 are connected by threads; the upper inner cavity of the upper outer cylinder 2 is a pressure relief cavity, and the inner circle of this pressure relief cavity is larger than the inner circle of the lower inner cavity. The pressure relief cavity in the upper part of the upper outer cylinder 2 allows the invention to eliminate the need for depressurizing the hydraulic cylinders on the ground after sealing the annulus. Once the central tube connector 3 at the upper end moves upward to the pressure relief cavity in the upper part of the upper outer cylinder 2, all hydraulic cylinders can be automatically depressurized, greatly facilitating construction. After backwashing out excess cement slurry, the inserted tubing can be removed to complete the construction.

[0045] In a preferred embodiment: To ensure that the hydraulic cylinders used in the later stages of operation can accurately work again during the annular sealing process, a slide cylinder 4 is also connected to the inner cavity of the central tube connector 3, which is connected to the upper connector 1 of the device. The hydraulic cylinders connected to the slide cylinder 4 are the hydraulic cylinders used in the later stages of operation. The slide cylinders 4 in the later stages of operation are all connected to the central tube connector 3 by shear pins, with the sealing ring in the slide cylinder 4 positioned above the fluid flow hole 8 of the connector. The hydraulic cylinders used in the later stages of operation are connected below the upper connector 1 of the device. Anti-loosening pins are also provided between the threaded connection sections of the upper connector 1 and the central tube connector 3, and between the central tube 6 and the central tube connector 3. By sealing the fluid flow hole 8 of the connector in the later stages of operation with the slide cylinder 4, the hydraulic cylinders used in the later stages of operation do not work during the mounting and dismounting processes of this suspension packer, but only work during the final sealing process, thus ensuring the effective operation of the present invention.

[0046] In a preferred embodiment, the anchoring mechanism further includes a slip cylinder 16. The slip cylinder 16 has a cylindrical structure with a slip assembly groove 16-1 machined in its wall to match the shape of the slip 15. A radial flow groove 16-2 is machined in the wall below the slip assembly groove 16-1. Threads are machined at both ends of the slip cylinder 16 to connect with the expansion sleeve 14 and the expansion sealing cylinder 17, respectively. The slip 15, installed in the slip assembly groove 16-1, is connected to the expansion cylinder 13 via shear studs. The mud flow groove in the expansion cylinder 13 and the radial flow groove 16-2 can jointly circulate cement slurry during cementing, thereby accelerating the cement slurry circulation speed.

[0047] In a preferred embodiment: the expansion sealing cylinder 17 is a non-uniform diameter cylindrical body, and a rubber sleeve 17-2 of the same height as the outer diameter is vulcanized in a constriction groove 17-1 in the middle of the outer diameter of the cylinder. The expansion sealing cylinder 17 has threads machined at both ends for connection to the slip sleeve 16 and the hanging sleeve 20, respectively. Both the expansion sealing cylinder 17 and the expansion retainer 14 are made of metal expansion tubing. Metal expansion tubing has excellent ductility, and after vulcanizing the rubber sleeve 17-2 in the constriction groove 17-1, the invention can better seal the annulus of the oil sleeve.

[0048] In a preferred embodiment: the locking cylinder 18 is a non-uniform diameter cylindrical structure, and one or more locking block through holes 18-4 and shear pin holes are machined in the cylinder body. The large inner diameter section below the shear pin hole is the locking block pushing cavity 18-3, and the locking block through hole 18-4 is machined in the locking block pushing cavity 18-3. The lower part of the locking cylinder 18 is a rubber plug insertion body 18-2 that matches the upper inner cavity of the large rubber plug 23, and a sealing ring groove is machined on the outer wall of the rubber plug insertion body 18-2. The lower part of the locking block pushing cavity 18-3 has a top cylinder sliding cavity 18-1 that matches the lower outer circle of the top cylinder 19. The internal thread provided on the upper inner circle of the locking cylinder 18 can be threadedly connected to the central tube connecting cylinder 12 and connected to the top cylinder 19 through shear pins in the inner cavity with shear pin holes.

[0049] In a preferred embodiment: the outer circle of the top cylinder 19 is a non-uniform diameter outer circle, and a shear pin connecting section 19-1, a lock block release section 19-2, a lock block pushing section 19-3, and a lock cylinder sliding section 19-4 are machined from top to bottom on the outer circle. The shear pin connecting section 19-1 is connected to the lock cylinder 18 by shear pins. The outer diameter of the lock block pushing section 19-3 is larger than that of the lock block release section 19-2 and has chamfers at both ends. The outer diameter of the lock block pushing section 19-3 matches the inner diameter of the internal thread section in the upper inner circle of the lock cylinder 18, so that the top cylinder 19 can be placed in the inner cavity of the lock cylinder 18. The lock cylinder sliding section 19-4 can be inserted into the top cylinder sliding cavity 18-1 in the lock cylinder 18.

[0050] In a preferred embodiment: the locking block 21 is an arc-shaped block with a linear cutting groove 21-3 machined axially on its inner wall. A leaf spring mounting groove 21-1 is machined within the clamping wall of the linear cutting groove 21-3. Both ends of the leaf spring mounting groove 21-1 have chamfers 21-2 at their inward exit points to facilitate leaf spring installation. A leaf spring is installed in the leaf spring mounting groove 21-1. After the locking block 21 is unlocked, the leaf spring allows the locking block 21 to easily enter the locking block release section 19-2.

[0051] In a preferred embodiment: the large rubber stopper 23 comprises a rubber stopper rigid body 23-1 and a large rubber stopper sealing body 23-2. The rubber stopper rigid body 23-1 is a non-uniform diameter cylindrical body, and its inner cavity, from top to bottom, consists of a locking cylinder mating cavity, a small rubber stopper insertion cavity, and a small rubber stopper holding cavity. The outer diameter of the rubber stopper rigid body 23-1 is provided with one or more sealing ring grooves and shear pin holes, and the outer diameter of the large rubber stopper sealing body 23-2 is vulcanized. The outer diameter of the large rubber stopper sealing body 23-2 is provided with three or more rubber wings. The outer diameter of the large rubber stopper sealing body 23-2 is larger than the inner diameter of the outer connecting cylinder 22 to increase its sealing performance.

[0052] In a preferred embodiment: the upper part of the rigid body of the small rubber stopper 10 is a solid structure, and the outer circle of the upper part of the rigid body is provided with an external thread section, a rubber stopper mounting section, and a rubber stopper limiting step 10-2 that can be connected to the retaining ring 11; a small rubber stopper fixing pawl 10-3 with a pawl anti-disengagement hook 10-4 at the lower end is provided below the rubber stopper limiting step 10-2; a small rubber stopper sealing body 10-1 is vulcanized outside the rubber stopper mounting section on the outer circle of the rigid body of the small rubber stopper 10, and the outer circle of the small rubber stopper sealing body 10-1 is provided with three or more rubber wings; the outer circles of the small rubber stopper sealing body 10-1 and the small rubber stopper fixing pawl 10-3 are both larger than the inner circles of the small rubber stopper delivery cavity and the small rubber stopper holding cavity in the large rubber stopper 23.

[0053] Construction method, used for the above one A type of suspended packer for side-drilling, characterized by comprising the following steps: A. Sending the suspended packer downhole and connecting it to the completion casing in the side-drilled well: During this process, the suspended packer is connected to the lower end of the feed string through the upper connector 1 of the device, the suspended packer is sent downhole and connected to the completion casing in the side-drilled well through the outer connecting sleeve 22. B. Setting up the suspended packer downhole: Hydraulic pressure is applied on the surface to pressurize the suspended packer downhole, enabling its setting up. During this process, high-pressure fluid enters the hydraulic cylinders that were previously in operation through the fluid flow holes 8 in the connectors 3 of all hydraulic cylinders between the central tube 6 and the central tube connecting cylinder 12. All hydraulic cylinders except those equipped with sliding sleeves 4, which are inactive, are operational. The expansion cylinder 13, connected to the lower hydraulic cylinder, moves relative to the central tube connecting cylinder 12. The expansion cylinder 13 causes the expansion sleeve 14 to expand in diameter. Simultaneously, the slips 15 are pushed out and engage with the completion casing in the side-drilled wellbore, completing the setting up of the device downhole.

[0054] C. Release of the suspended packer downhole: During this process, the hydraulic pressure continues to increase on the surface. The top cylinder 19 slides up and down in the top cylinder sliding cavity 18-1 of the locking cylinder 18 and shears off the shear pin between it and the locking cylinder 18, releasing and unlocking the locking block 21. Under the action of the leaf spring, the locking block 21 smoothly enters the locking block release section 19-2. At this time, the tubing string can be lifted a certain distance on the surface to verify the release effect of the suspended packer.

[0055] D. Seal the annulus of the oil jacket using a suspension packer: After the suspended packer is released downhole, the surface continues to pressurize to open the cementing float at the lower end of the completion casing string for cementing. After the cement slurry is injected, small rubber plug 10 and large rubber plug 23 are combined and then used to displace the cement slurry from the surface to the bottom of the well completion casing string. The float shoe installed at the bottom of the casing string is then closed. Depressurize on the ground, lower the working column so that the expansion cylinder 13 contacts the expansion sealing cylinder 17 equipped with rubber cylinder 17-2, and lower the column to the preset tonnage so that the hydraulic cylinder above the central pipe connecting cylinder 12 that worked in the previous stage can be reset. On the ground, pressure continues to be applied to the predetermined value. All hydraulic cylinders operate simultaneously, causing the expansion cylinder 13 to continue pushing down the rubber sleeve 17-2 of the expansion sealing cylinder 17, allowing the expansion sealing cylinder 17 to fully expand its diameter and the rubber sleeve 17-2 to seal the annulus of the oil sleeve. After the annulus of the oil sleeve is sealed, the sealing ring in the uppermost hydraulic cylinder moves to the pressure relief chamber of the upper outer cylinder 2, and the inserted tubing is automatically depressurized. Afterward, the inserted tubing is lifted to allow the locking cylinder 18 to be removed from the expansion retainer 14. After a large-volume well flush, the inserted tubing is removed to complete the construction.

[0056] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A suspended packer for sidetracking wells, comprising a hydraulic cylinder and an anchoring mechanism, characterized in that: A hydraulic cylinder of level two or above is installed and connected to the lower part of the upper connector (1) of the device. The upper part of the central tube (6) of the hydraulic cylinder in the early stage is not equipped with a sealing ring. The hydraulic cylinders are connected to the outer cylinder connector (5) through the central tube connector (3) with the connecting head liquid flow hole (8). The central tube connector (3) in the upper hydraulic cylinder is connected to the upper connector (1) of the device. The upper outer cylinder (2) and the outer cylinder (7) of the lower hydraulic cylinder with the outer cylinder liquid inlet hole (9) are connected through the outer cylinder connector (5). The bottom of the central tube connecting cylinder (12), which is connected to the central tube (6) of the lower hydraulic cylinder, is connected to the top cylinder (19) and the large rubber plug (23) via the locking cylinder (18). The small rubber plug (10) can be inserted into the large rubber plug (23). Below the expansion cylinder (13) with mud flow channel connected to the outer cylinder connector (5) in the lower hydraulic cylinder is an anchoring mechanism consisting of an expansion sleeve (14), a slip (15), an expansion sealing cylinder (17) with a rubber sleeve (17-2) and a hanging cylinder (20) connected in sequence, as well as an outer connecting cylinder (22) connected to the completion casing in the side drilling well; The top cylinder (19) is installed in the inner cavity of the lower part of the lock cylinder (18) and the lock block (21) is sealed in the lock block limiting groove (20-1) in the hanging cylinder (20) outside the top cylinder (19).

2. A side-drilling suspended packer as described in claim 1, characterized in that, The central tube (6) and the central tube connector (30), the central tube connector (12) and the central tube connector (3), the central tube connector (12) and the lock cylinder (18), and the lock cylinder (18) and the large rubber plug (23) are all connected by shear pins and sealed by sealing rings; the central tube (6) and the central tube connector (3) are connected by threads; the upper inner cavity of the upper outer cylinder (2) is a pressure relief cavity, and the inner circle of the pressure relief cavity is larger than the inner circle of the lower inner cavity.

3. A side-drilling suspended packer as described in claim 2, characterized in that, in A slide cylinder (4) is also connected to the inner cavity of the central tube connector (3) connected to the upper connector (1) of the device. The hydraulic cylinder connected to the slide cylinder (4) is the hydraulic cylinder for later operation. The slide cylinder (4) in the hydraulic cylinder for later operation is connected to the central tube connector (3) by shear pins, and the sealing ring in the slide cylinder (4) is located above the fluid flow hole (8) of the connector. The hydraulic cylinder for later operation is connected to the lower part of the upper connector (1) of the device. Anti-loosening pins are also provided between the threaded connection section of the upper connector (1) of the device and the central tube connector (3) and between the threaded connection section of the central tube (6) and the central tube connector (3).

4. A side-drilling suspended packer as described in claim 3, characterized in that, The anchoring mechanism is further provided with a slip cylinder (16), which is a cylindrical structure and has a slip assembly groove (16-1) that matches the shape of the slip (15) in the cylinder wall. A radial flow groove (16-2) is also machined in the cylinder wall below the slip assembly groove (16-1). Threads that can be connected to the expansion sleeve (14) and the expansion sealing cylinder (17) are machined at both ends of the slip cylinder (16). The slip (15) installed in the slip assembly groove (16-1) is connected to the expansion cylinder (13) by a shear pin.

5. A side-drilling suspended packer as described in claim 4, characterized in that, The expansion sealing cylinder (17) is a non-uniform diameter cylindrical body, and a rubber sleeve (17-2) of the same height as the outer circle is vulcanized in the narrowing groove (17-1) in the middle of the outer circle of the cylinder. The expansion sealing cylinder (17) has threads at both ends that are connected to the slip cylinder (16) and the hanging cylinder (20). The bodies of the expansion sealing cylinder (17) and the expansion sleeve (14) are both made of metal expansion tubes.

6. A side-drilling suspended packer as described in claim 4, characterized in that, The locking cylinder (18) is a non-uniform diameter cylindrical structure with one or more locking block through holes (18-4) and shear pin holes machined in the cylinder body. The large inner diameter section below the shear pin hole is the locking block pushing cavity (18-3), and the locking block through hole (18-4) is machined in the locking block pushing cavity (18-3). The lower part of the locking cylinder (18) is a rubber plug insertion body (18-2) that matches the upper inner cavity of the large rubber plug (23), and a sealing ring groove is machined on the outer wall of the rubber plug insertion body (18-2). The lower part of the locking block pushing cavity (18-3) has a top cylinder sliding cavity (18-1) that matches the lower outer circle of the top cylinder (19). The internal thread provided on the upper inner circle of the locking cylinder (18) can be threadedly connected to the central tube connecting cylinder (12) and connected to the top cylinder (19) through shear pins in the inner cavity with shear pin holes.

7. A side-drilling suspended packer as described in claim 6, characterized in that, The outer circle of the top cylinder (19) is a non-uniform diameter outer circle, and the outer circle is machined from top to bottom with a shear pin connecting section (19-1), a lock block release section (19-2), a lock block pushing section (19-3), and a lock cylinder sliding section (19-4). The shear pin connecting section (19-1) is connected to the lock cylinder (18) by shear pins. The outer diameter of the lock block pushing section (19-3) is larger than that of the lock block release section (19-2) and has chamfers at both ends. The outer diameter of the lock block pushing section (19-3) matches the inner diameter of the internal thread section in the upper inner circle of the lock cylinder (18), so that the top cylinder (19) can be placed in the inner cavity of the lock cylinder (18). The lock cylinder sliding section (19-4) can be inserted into the top cylinder sliding cavity (18-1) in the lock cylinder (18).

8. A side-drilling suspended packer as described in claim 4, characterized in that, The locking block (21) is an arc-shaped block with a linear cutting groove (21-3) machined on its inner wall along the axial direction. A leaf spring mounting groove (21-1) is machined in the clamping wall of the linear cutting groove (21-3). Both ends of the leaf spring mounting groove (21-1) are chamfered (21-2) at the inward outlet to facilitate the installation of the leaf spring. A leaf spring is installed in the leaf spring mounting groove (21-1).

9. A side-drilling suspended packer as described in claim 4, characterized in that, The large rubber stopper (23) is provided with a rubber stopper rigid body (23-1) and a large rubber stopper sealing body (23-2). The rubber stopper rigid body (23-1) is a non-uniform diameter cylindrical body and its inner cavity consists of a locking cylinder mating cavity, a small rubber stopper insertion cavity, and a small rubber stopper holding cavity from top to bottom. The outer diameter of the rubber stopper rigid body (23-1) is provided with one or more sealing ring grooves and shear pin holes, and the outer diameter of the large rubber stopper sealing body (23-2) is vulcanized. The outer diameter of the large rubber stopper sealing body (23-2) is provided with three or more rubber wings. The outer diameter of the large rubber stopper sealing body (23-2) is larger than the inner diameter of the outer connecting cylinder (22).

10. A side-drilling suspended packer as described in claim 9, characterized in that, The upper part of the rigid body of the small rubber stopper (10) is a solid structure and has an external thread section, a rubber stopper installation section and a rubber stopper limiting step (10-2) that can be connected to the retaining ring (11) on the outer circle of the upper part of the rigid body; a small rubber stopper fixing pawl (10-3) with a pawl anti-disengagement hook (10-4) at the lower end is provided below the rubber stopper limiting step (10-2); a small rubber stopper sealing body (10-1) is vulcanized outside the rubber stopper installation section on the outer circle of the rigid body of the small rubber stopper (10), and the outer circle of the small rubber stopper sealing body (10-1) is provided with more than three rubber wings; the outer circles of the small rubber stopper sealing body (10-1) and the small rubber stopper fixing pawl (10-3) are both larger than the inner circles of the small rubber stopper delivery cavity and the small rubber stopper holding cavity in the large rubber stopper (23).

11. A construction method for a side-drilling suspended packer as described in any one of claims 4-10, characterized in that, Includes the following steps: A. Deploy the suspended packer downhole and connect it to the completion casing in the side-drilled well; B. The packer is mounted downhole; C. The suspended packer is released downhole; D. Seal the annulus of the oil jacket by using a suspended packer.

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