A casing packer lowering and recovery device and its construction process

Abstract

The present invention is a casing packer lowering and recovery device and its construction process. The casing packer lowering and recovery device includes a lowering tool for connecting with the packer and lowering it to the sealing position in the casing, a sealing steel ball for completing the sealing, and a release steel ball for separating the lowering tool from the packer; it also includes a recovery tool and an unlocking steel ball for connecting with the packer and lifting it out of the casing; the process includes packer sealing, lowering tool separation, and packer recovery. The packer lowering and recovery device of the present invention realizes the downhole sealing and anchoring of a single packer through the pressure transmission method in the pipe and cooperates with a special lowering tool to complete the downhole stratification of the packer; when the packer needs to be recovered, it is docked with the downhole packer through a special recovery tool, and the packer is unlocked and recovered through mechanical methods such as lifting or pressing down the pipe string.

Description

Technical Field

[0001] The invention relates to the technical field of packer construction, and in particular to a casing inner packer lowering and recovery device and a construction process thereof. Background Art

[0002] At present, in the oil extraction industry, there are many types of packers, and various ways of delivery and recovery. However, the performance and reliability of the tools vary. They are subject to multiple restrictions such as the packer model and the oil production environment. Especially when large-diameter packers are required, the existing delivery and recovery methods are often not up to the task.

[0003] In view of the current status of packers, the present invention designs a packer lowering and recovering device and a construction process thereof with good versatility and stable and reliable performance. Summary of the invention

[0004] The present invention aims to solve the deficiencies of the prior art and provides a casing inner packer lowering and recovery device and a construction process thereof.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A casing inner packer lowering and recovery device, comprising a lowering tool for connecting with the packer and lowering it to a sealing position in the casing, a sealing steel ball for completing the sealing, and a release steel ball for separating the lowering tool from the packer;

[0007] Also included is a retrieval tool and unlocking ball for connecting to the packer and lifting it out of the casing.

[0008] The lowering tool comprises a releasing tool, a releasing tool oil pipe connecting buckle is provided on the top of the releasing tool, an elastic claw connected to the upper end of the inner wall of the packer is provided on the bottom of the releasing tool, a T-shaped inner cavity is provided in the releasing tool, a center sealing cylinder is installed in the T-shaped inner cavity, an annular strap is provided on the top of the center sealing cylinder at the upper end of the T-shaped inner cavity, an annular groove for the elastic claw to shrink is provided on the upper end of the outer wall of the center sealing cylinder, the lower end of the center sealing cylinder passes through the bottom of the elastic claw and extends into the interior of the packer, sealing rings are provided on the upper and lower ends of the part of the center sealing cylinder extending into the interior of the packer, a pressure transmission hole is provided on the outer wall of the center sealing cylinder between the two sealing rings, the outer wall of the center sealing cylinder and the inner wall of the packer form a pressure sealing cavity between the two sealing rings, and a sealing ball seat is provided on the lower end of the inner wall of the center sealing cylinder.

[0009] When the packer is seated, the sealing steel ball is put into the sealing ball seat, and when the packer is separated from the lowering tool, the release steel ball is put into the upper end of the inner wall of the central sealing cylinder in the release tool.

[0010] The recovery tool comprises a recovery pipe string, a recovery tool oil pipe connecting buckle is arranged at the top of the recovery pipe string, a locking mechanism connected with the packer is arranged at the bottom of the recovery pipe string, and a safety device for retracting the locking mechanism is arranged inside the recovery pipe string.

[0011] The locking mechanism is a hollow tubular structure, a retaining ring plate is provided at the upper end of the outer wall of the locking mechanism, and an elastic protrusion connected to the inner wall of the packer is provided at the lower end of the outer wall of the locking mechanism.

[0012] The safety device is a hollow tubular structure, a limiting ring plate is provided at the upper end of the outer wall of the safety device, a boss supporting the bottom of the elastic protrusion is provided at the lower end of the outer wall of the safety device, and an annular shrinkage groove is provided above the boss for the elastic protrusion to retract on the outer wall of the safety device.

[0013] An installation inner tube is provided in the recovery pipe column, and an annular cylinder extending out from the bottom of the recovery pipe column is provided at the bottom of the installation inner tube, a lap platform is formed between the top of the annular cylinder and the inner wall of the installation inner tube, and the locking ring plate of the outer wall of the locking mechanism is overlapped on the lap platform, a fixing tube is provided at the upper end of the installation inner tube, and a limiting plate for preventing the safety device ring plate from falling off is provided at the bottom of the fixing tube, and the limiting ring plate at the upper end of the outer wall of the safety device is located in the fixing tube.

[0014] When the recovery tool is stuck, the unlocking steel ball is dropped into the upper end of the inner wall of the safety device.

[0015] A construction process for a casing packer lowering and recovery device, the specific steps are:

[0016] S1, Packer Seat

[0017] Assemble the elastic claws of the lowering tool with the inner wall of the packer, and form a pressure sealing cavity between the upper and lower sealing rings of the center sealing cylinder and the inner wall of the packer; when entering the well, connect the lowering tool tubing connector of the lowering tool with the tubing and lower it into the casing. After reaching the sealing position, manually throw the sealing steel ball to the sealing ball seat, and start the string pressure operation, so that the hydraulic pressure enters the pressure sealing cavity through the pressure transmission hole on the center sealing cylinder, and completes the sealing and anchoring of the packer;

[0018] S2. Separation of lowering tools

[0019] After the packer is sealed, continue to increase the string pressure to knock out the sealing ball seat. At this time, put the release steel ball into the upper end of the inner wall of the central sealing cylinder in the release tool. By pressing, the central sealing cylinder descends, so that the elastic claws retract into the annular groove, and the release tool is released to complete the separation of the lowering tool and the packer. Then, lift the tubing and lift out the entire lowering tool.

[0020] S3. Packer recovery

[0021] When the packer needs to be recovered, the recovery tool tubing connector on the top of the recovery tool is connected to the tubing on the ground, and the tools are lowered to the position of the packer through the tubing. The elastic protrusion of the locking mechanism at the bottom of the recovery tool is connected to the packer, and the packer is unsealed by mechanical operations of lifting or lowering the tubing to achieve packer recovery.

[0022] In step S3, when encountering obstacles during the recovery process, an unlocking steel ball is thrown by hand to press the safety device downward, so that the elastic protrusion retracts into the annular shrinkage groove, the safety device is unlocked, and the recovery tool is quickly separated from the packer without affecting subsequent salvage operations.

[0023] The beneficial effects of the present invention are as follows: the packer lowering and recovery device of the present invention, through the pressure transmission method in the pipe, cooperates with the special lowering tool to realize the downhole sealing and anchoring of a single packer, and completes the downhole stratification of the packer; when the packer needs to be recovered, it is connected with the downhole packer through the special recovery tool, and the packer is unsealed and recovered through mechanical methods such as lifting or pressing down the pipe string. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the lowering tool;

[0025] Figure 2 It is a schematic diagram of the structure when the lowering tool lowers the packer;

[0026] Figure 3 It is a schematic diagram of the structure of the recovery tool;

[0027] Figure 4 A schematic diagram of the structure of the recovery tool when recovering the packer;

[0028] In the figure: 1-packer; 2-casing; 3-lowering tool; 4-sealing steel ball; 5-hand-off steel ball; 6-recovery tool; 7-unlocking steel ball; 8-hand-off tool; 9-lowering tool oil pipe connecting buckle; 10-elastic claw; 11-center sealing cylinder; 12-annular strap; 13-annular groove; 14-sealing ring; 15-pressure transmission hole; 16-pressure sealing cavity; 17-sealing ball seat; 18-recovery pipe string; 19-recovery tool oil pipe connecting buckle; 20-locking mechanism; 21-safety device; 22-installation inner pipe; 23-annular cylinder; 24-elastic protrusion; 25-fixing pipe; 26-annular shrinkage groove; 27-oil pipe;

[0029] The following is a detailed description of the embodiments of the present invention with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0031] like Figures 1 to 4As shown, a casing inner packer lowering and recovery device comprises a lowering tool 3 for connecting with a packer 1 and lowering it to a sealing position in a casing 2, a sealing steel ball 4 for completing the sealing, and a release steel ball 5 for separating the lowering tool 3 from the packer 1;

[0032] It also includes a recovery tool 6 and an unlocking steel ball 7 for connecting with the packer 1 and lifting it out of the casing 2.

[0033] The lowering tool 3 includes a releasing tool 8, a releasing tool oil pipe connecting buckle 9 is provided on the top of the releasing tool 8, an elastic claw 10 for connecting with the upper end of the inner wall of the packer 1 is provided on the bottom of the releasing tool 8, a T-shaped inner cavity is provided in the releasing tool 8, a center sealing cylinder 11 is installed in the T-shaped inner cavity, a ring-shaped strap 12 is provided on the top of the center sealing cylinder 11, an annular groove 13 for the elastic claw 10 to shrink is provided on the upper end of the outer wall of the center sealing cylinder 11, the lower end of the center sealing cylinder 11 passes through the bottom of the elastic claw 10 and extends into the interior of the packer 1, and the upper and lower ends of the part of the center sealing cylinder 11 extending into the interior of the packer 1 are both provided with sealing rings 14, a pressure transmission hole 15 is provided on the outer wall of the center sealing cylinder 11 between the two sealing rings 14, the outer wall of the center sealing cylinder 11 and the inner wall of the packer 1 form a pressure sealing cavity 16 between the two sealing rings 14, and a sealing ball seat 17 is provided at the lower end of the inner wall of the center sealing cylinder 11.

[0034] When the packer 1 is seated, the sealing steel ball 4 is dropped onto the sealing ball seat 17 , and when the packer 1 is separated from the lowering tool 3 , the release steel ball 5 is dropped into the upper end of the inner wall of the central sealing tube 11 in the release tool 8 .

[0035] The recovery tool 6 includes a recovery string 18, a recovery tool oil pipe connector 19 is provided at the top of the recovery string 18, a locking mechanism 20 connected to the packer 1 is provided at the bottom of the recovery string 18, and a safety device 21 for retracting the locking mechanism 20 is provided inside the recovery string 18.

[0036] The locking mechanism 20 is a hollow tubular structure. A retaining ring plate is provided at the upper end of the outer wall of the locking mechanism 20 , and an elastic protrusion 24 connected to the inner wall of the packer 1 is provided at the lower end of the outer wall of the locking mechanism 20 .

[0037] The safety device 21 is a hollow tubular structure. A limiting ring plate is provided at the upper end of the outer wall of the safety device 21. A boss supporting the bottom of the elastic protrusion 24 is provided at the lower end of the outer wall of the safety device 21. An annular shrinkage groove 26 for the elastic protrusion 24 to retract is provided above the boss on the outer wall of the safety device 21.

[0038] An installation inner tube 22 is provided in the recovery pipe column 18, and an annular tube 23 extending out from the bottom of the recovery pipe column 18 is provided at the bottom of the installation inner tube 22. A lap joint is formed between the top of the annular tube 23 and the inner wall of the installation inner tube 22. The locking ring plate of the outer wall of the locking mechanism 20 is overlapped on the lap joint. A fixing tube 25 is provided at the upper end of the installation inner tube 22. A limiting plate for preventing the ring plate of the safety device 21 from falling off is provided at the bottom of the fixing tube 25. The limiting ring plate at the upper end of the outer wall of the safety device 21 is located in the fixing tube 25.

[0039] When the recovery tool 6 is stuck, the unlocking steel ball 7 is dropped into the upper end of the inner wall of the safety device 21 .

[0040] A construction process for a casing packer lowering and recovery device, the specific steps are:

[0041] S1, Packer 1 seal

[0042] The elastic claws 10 of the lowering tool 3 are assembled with the inner wall of the packer 1, and the center sealing tube 11 forms a pressure sealing cavity 16 with the inner wall of the packer 1 by using the upper and lower sealing rings 14; when entering the well, the lowering tool oil pipe connecting buckle 9 of the lowering tool 3 is connected with the oil pipe 27 and lowered into the casing 2, and after reaching the sealing position, the sealing steel ball 4 is manually thrown to the sealing ball seat 17, and the pipe string pressure operation is started, so that the hydraulic pressure enters the pressure sealing cavity 16 through the pressure transmission hole 15 on the center sealing tube 11, and the sealing and anchoring of the packer 1 are completed;

[0043] S2, separation of lowering tool 3

[0044] After the packer 1 is sealed, the string pressure is further increased to knock out the sealing ball seat 17. At this time, the release steel ball 5 is inserted into the upper end of the inner wall of the central sealing cylinder 11 in the release tool. By pressing, the central sealing cylinder 11 descends, so that the elastic claw 10 is retracted into the annular groove 13, and the release tool 8 is released to complete the separation of the lowering tool 3 and the packer 1. The oil pipe 27 is lifted up, and the entire lowering tool 3 is lifted out.

[0045] S3, Packer 1 recovery

[0046] When the packer 1 needs to be recovered, the recovery tool oil pipe connecting buckle 19 on the top of the recovery tool 6 is connected to the oil pipe 27 on the ground, and lowered to the position of the packer 1 through the oil pipe 27. The elastic protrusion 24 of the locking mechanism 20 at the bottom of the recovery tool 6 is connected to the packer 1, and the packer 1 is unsealed by mechanical operation of lifting or lowering the oil pipe 27 to achieve recovery of the packer 1.

[0047] In step S3, when encountering obstacles during the recovery process, the unlocking steel ball 7 is thrown by hand to press the safety device 21 downward, so that the elastic protrusion 24 retracts into the annular shrinkage groove 26, thereby completing the unlocking of the safety device 21 and quickly separating the recovery tool 6 from the packer 1 without affecting the subsequent salvage operation.

[0048] The device for lowering and recovering the packer 1 of the present invention realizes the downhole sealing and anchoring of a single packer 1 by means of pressure transmission in the pipe in cooperation with a special lowering tool 3, and completes the downhole stratification of the packer 1; when the packer 1 needs to be recovered, the special recovery tool 6 is connected to the downhole packer 1, and the packer 1 is unsealed and recovered by mechanical means such as lifting or pressing down the pipe string.

[0049] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various improvements are made using the method concept and technical solution of the present invention, or are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A casing packer lowering and recovery device, characterized in that: It comprises a lowering tool (3) for connecting with the packer (1) and lowering it to the sealing position in the casing (2), a sealing steel ball (4) for completing the sealing, and a release steel ball (5) for separating the lowering tool (3) from the packer (1); it also comprises a recovery tool (6) and an unlocking steel ball (7) for connecting with the packer (1) and lifting it out of the casing (2); The lowering tool (3) comprises a release tool (8), the top of the release tool (8) is provided with a release tool oil pipe connecting buckle (9), the bottom of the release tool (8) is provided with an elastic claw (10) for connecting with the upper end of the inner wall of the packer (1), the release tool (8) is provided with a T-shaped inner cavity, a center sealing cylinder (11) is installed in the T-shaped inner cavity, the top of the center sealing cylinder (11) is provided with an annular strap (12) located at the upper end of the T-shaped inner cavity, and the upper end of the outer wall of the center sealing cylinder (11) is provided with an annular groove (12) for the elastic claw (10) to contract. 3), the lower end of the central sealing tube (11) passes through the bottom of the elastic claw (10) and extends into the interior of the packer (1), the upper end and the lower end of the part of the central sealing tube (11) extending into the interior of the packer (1) are both provided with sealing rings (14), a pressure transmission hole (15) is provided on the outer wall of the central sealing tube (11) between the two sealing rings (14), the outer wall of the central sealing tube (11) and the inner wall of the packer (1) form a pressure sealing cavity (16) between the two sealing rings (14), and a sealing ball seat (17) is provided at the lower end of the inner wall of the central sealing tube (11); The recovery tool (6) comprises a recovery pipe string (18), the top of the recovery pipe string (18) is provided with a recovery tool oil pipe connection buckle (19), the bottom of the recovery pipe string (18) is provided with a locking mechanism (20) connected to the packer (1), and a safety device (21) for retracting the locking mechanism (20) is provided inside the recovery pipe string (18); the locking mechanism (20) is a hollow tubular structure, the upper end of the outer wall of the locking mechanism (20) is provided with a retaining ring plate, and the lower end of the outer wall of the locking mechanism (20) is provided with an elastic protrusion (24) connected to the inner wall of the packer (1); the safety device (21) is a hollow tubular structure, the upper end of the outer wall of the safety device (21) is provided with a limiting ring plate, the lower end of the outer wall of the safety device (21) is provided with a boss supporting the bottom of the elastic protrusion (24), and the outer wall of the safety device (21) is provided with an annular shrinkage groove (26) above the boss for retracting the elastic protrusion (24).

2. The casing packer lowering and recovery device according to claim 1, characterized in that: When the packer (1) is seated, the sealing steel ball (4) is dropped onto the sealing ball seat (17); when the packer (1) is separated from the lowering tool (3), the release steel ball (5) is dropped into the upper end of the inner wall of the central sealing cylinder (11) in the release tool (8).

3. The casing packer lowering and recovery device according to claim 2, characterized in that: An installation inner tube (22) is provided in the recovery pipe column (18), an annular tube (23) extending out of the bottom of the recovery pipe column (18) is provided at the bottom of the installation inner tube (22), a lap joint is formed between the top of the annular tube (23) and the inner wall of the installation inner tube (22), a locking ring plate of the outer wall of the locking mechanism (20) is lapped on the lap joint, a fixing tube (25) is provided at the upper end of the installation inner tube (22), a limiting plate for preventing the limiting ring plate of the safety device (21) from falling off is provided at the bottom of the fixing tube (25), and the limiting ring plate at the upper end of the outer wall of the safety device (21) is located in the fixing tube (25).

4. The casing packer lowering and recovery device according to claim 3, characterized in that: When the recovery tool (6) is stuck, the unlocking steel ball (7) is dropped into the upper end of the inner wall of the safety device (21).

5. A construction process using the casing packer lowering and recovery device as claimed in claim 4, characterized in that: The specific steps are: S1, Packer (1) Sealing The elastic claw (10) of the lowering tool (3) is assembled with the inner wall of the packer (1), and a pressure sealing chamber (16) is formed between the center sealing tube (11) and the inner wall of the packer (1) by using the upper and lower sealing rings (14); when entering the well, the lowering tool oil pipe connecting buckle (9) of the lowering tool (3) is connected to the oil pipe (27) and lowered into the casing (2), and after reaching the sealing position, the sealing steel ball (4) is manually thrown to the sealing ball seat (17), and the pipe string pressure operation is started, so that the hydraulic pressure enters the pressure sealing chamber (16) through the pressure transmission hole (15) on the center sealing tube (11), and the sealing and anchoring of the packer (1) are completed; S2, lowering tool (3) separation After the packer (1) is seated, the string pressure is further increased to knock out the sealing ball seat (17). At this time, the release steel ball (5) is inserted into the upper end of the inner wall of the central sealing cylinder (11) in the release tool. By pressing, the central sealing cylinder (11) descends, so that the elastic claw (10) retracts into the annular groove (13), and the release tool (8) is released to complete the separation of the lowering tool (3) and the packer (1). The oil pipe (27) is lifted up to lift out the entire lowering tool (3); S3. Packer (1) recovery When the packer (1) needs to be recovered, the recovery tool oil pipe connection buckle (19) on the top of the recovery tool (6) is connected to the oil pipe (27) on the ground, and the oil pipe (27) is lowered to the position of the packer (1). The elastic protrusion (24) of the locking mechanism (20) at the bottom of the recovery tool (6) is connected to the packer (1), and the packer (1) is unsealed by mechanical operation of lifting or lowering the oil pipe (27), thereby realizing the recovery of the packer (1).

6. The construction process of the casing packer lowering and recovery device according to claim 5, characterized in that: In step S3, when an obstacle is encountered during the recovery process, the unlocking steel ball (7) is thrown in by hand to press the safety device (21) downward, so that the elastic protrusion (24) retracts into the annular shrinkage groove (26), thereby completing the unlocking of the safety device (21) and quickly separating the recovery tool (6) from the packer (1) without affecting subsequent salvage operations.

Images