Step-by-step layered plugging tool

Abstract

A step-by-step layering plugging tool comprises a central pipe, an upper connector and a lower connector are fixedly installed at the upper end and the lower end of the central pipe, an outer barrel, an upper pressing cap, a rubber barrel pipe, an unsealing sleeve, a lower pressing cap, a connecting pipe, a seat sealing sleeve, a lower piston and a cylinder sleeve are arranged on the outer circle face of the central pipe in a sleeved mode, an open clamping ring is arranged on the outer circle face of the unsealing sleeve in a clamped mode, and fixed teeth are arranged on the outer circle face of the clamping ring. The cylinder sleeve is fixedly installed on the outer circle face of the lower connector, the lower pressing cap, the connecting pipe, the setting sleeve and the lower piston are sequentially and fixedly installed from top to bottom, the inner circle face of the lower pressing cap is installed on the outer circle face of the rubber sleeve pipe in an up-down sliding mode, and the lower piston slides up and down and is installed between the cylinder sleeve and the center pipe in a sealed mode. A water inlet hole is formed in the central pipe corresponding to the lower end of the lower piston; and a rubber sleeve is sleeved on the excircle surface of the rubber sleeve pipe between the upper pressing cap and the lower pressing cap. After water injection is stopped, the plugging state is still kept, mutual circulation of water between stratums is prevented, and it is guaranteed that the pressure between the stratums is balanced.

Description

Technical Field

[0001] The utility model relates to a plugging tool for water injection during oil field production, in particular to a step-by-step layered plugging tool. Background Art

[0002] When oilfield production enters the middle and late stages, the formation becomes depleted, interlayer pressure is low, and crude oil permeability is low, making crude oil extraction difficult. Water injection into the formation is necessary to control interlayer pressure and improve extraction efficiency. During water injection, a seal must be established between the tubing and the casing surrounding it to ensure that the injected water enters the designated stratum.

[0003] Currently, plugging tools primarily include mechanical and hydraulic ones. Mechanical plugging tools have limitations and are significantly affected by well depth and well conditions. They also require ballasting at the wellhead during the plugging process, and strict operational controls are essential. Hydraulic plugging tools overcome these limitations. Once lowered into the well, they only require ground pressure to complete the plugging process. However, when water injection is stopped, the hydraulic plugging effect is lost due to a loss of water pressure, leading to inter-stratum water flow. This prevents pressure balance between strata when water is injected again. Utility Model Content

[0004] The utility model aims to solve the above technical problems and provides a step-by-step layered plugging tool, which can maintain the plugging state after stopping water injection, prevent water from flowing between strata, and ensure that the pressure between strata is balanced.

[0005] The technical solution of this utility model is:

[0006] The cam is secured to the bottom of the cylinder and is secured to the cam face with an angular channel formed between the top and bottom of the cylinder, the cam being secured to the cam face with a channel slot that receives the piston rod and the piston rod washer.

[0007] Furthermore, a locking mechanism is provided between the unsealing sleeve and the seating sleeve, so that the step-by-step layered plugging tool can avoid the phenomenon of premature plugging caused by upward movement of the lower piston during the process of being placed into the casing.

[0008] Furthermore, the locking mechanism is a seat seal shear pin fixedly installed between the unsealing sleeve and the seat seal sleeve, which locks the seat seal sleeve. The water pressure generated by injecting water into the central tube pushes the seat seal sleeve upward through the lower piston, cutting off the seat seal shear pin and unlocking the seat seal sleeve.

[0009] Furthermore, an unlocking mechanism is provided between the central tube and the rubber tube.

[0010] Furthermore, the unlocking mechanism includes a claw which is arranged at the upper end of the unlocking sleeve and distributed circumferentially. The claw is installed on the inner circular surface of the rubber tube through a thread. A boss which fits with the inner circular surface of the claw is provided on the outer circular surface of the center tube. When the center tube is moved upward, the claw is separated from the restraint of the boss. Under the action of the rebound force of the rubber tube, the seat sleeve generates a downward thrust on the claw. The thread on the rubber tube generates a radial inward lateral component of force on the thread on the claw. The claw shrinks inward and separates from the rubber tube. The unlocking sleeve drives the seat sleeve to move downward, and the rubber tube shrinks to release the blockage.

[0011] Furthermore, a cleaning mechanism is provided between the upper pressure cap and the central tube.

[0012] Furthermore, the cleaning mechanism includes a well-washing piston that slides up and down and is sealed and installed between the upper pressure cap and the center tube, a spring is connected between the well-washing piston and the front end face of the outer tube, the upper pressure cap is provided with circumferentially distributed upper flow holes, and the connecting tube is provided with circumferentially distributed lower flow holes. Water is injected between the oil pipe and the casing, and the injected water enters through the upper flow holes and pushes the well-washing piston upward, and then enters between the oil pipe and the casing through the lower flow holes, and enters the interior of the bridge-type concentric profile adjustment tool on the oil pipe, so as to clean the bridge-type concentric profile adjustment tool and the oil pipe.

[0013] Furthermore, there are multiple rubber cylinders, which are arranged up and down. When sealing, the deformation area of the rubber cylinder is increased, and the friction between the rubber cylinder and the sleeve is improved.

[0014] The beneficial effects of the utility model are:

[0015] Water injected through the oil pipe enters the space between the center tube and the cylinder sleeve through the water inlet hole, and pushes the rubber sleeve upward through the lower piston, seat seal, connecting pipe, and lower pressure cap. Under the squeezing action of the upper and lower pressure caps, the rubber sleeve deforms and expands tightly against the inner wall of the casing. The movable teeth on the seat seal mesh with the fixed teeth on the retaining ring to achieve sealing. The sealing is opened by water pressure, and the opening structure is simple and convenient, effectively ensuring the smooth opening of the sealing tool. The rubber sleeve is squeezed and deformed by the indirect action of water pressure and expands tightly against the inner wall of the casing. The sealing structure is firm and has no gaps, and the sealing is tight. After water injection stops, the movable teeth on the seat seal mesh with the fixed teeth on the retaining ring. The rubber sleeve cannot rebound and remains sealed, effectively preventing water from circulating between strata and ensuring pressure balance between strata. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the utility model;

[0017] Figure 2 yes Figure 1 Schematic diagram of the structure of the middle clamping ring;

[0018] In the figure: 1-center tube, 2-upper joint, 3-lower joint, 4-outer tube, 5-upper pressure cap, 6-rubber tube, 7-unsealing sleeve, 8-lower pressure cap, 9-connecting pipe, 10-seat sleeve, 11-lower piston, 12-cylinder sleeve, 13-claw, 14-boss, 15-circlip, 16-fixed tooth, 17-opening, 18-movable tooth, 19-seat seal shear nail, 20-water inlet hole, 21-rubber cylinder, 22-well washing piston, 23-spring, 24-upper flow hole, 25-lower flow hole. DETAILED DESCRIPTION

[0019] like Figure 1-Figure 2 As shown, a step-by-step layered plugging tool includes a center tube 1, an upper joint 2 and a lower joint 3 are fixedly installed at the upper and lower ends of the center tube 1, an outer tube 4, an upper pressure cap 5, a rubber tube 6, an unsealing sleeve 7, a lower pressure cap 8, a connecting tube 9, a seat sleeve 10, a lower piston 11 and a cylinder sleeve 12 are set on the outer cylindrical surface of the center tube 1, the upper joint 2, the outer tube 4, the upper pressure cap 5, the rubber tube 6 and the seat sleeve 10 are fixedly installed in sequence up and down, a circumferentially distributed clamping claw 13 is provided on the upper end of the unsealing sleeve 7, the clamping claw 13 is installed on the inner cylindrical surface of the rubber tube 6 through a thread, a boss 14 is provided on the outer cylindrical surface of the center tube 1, a clamping ring 15 with an opening 17 is clamped on the outer cylindrical surface of the unsealing sleeve 7, and a fixed tooth 16 is provided on the outer cylindrical surface of the clamping ring 15 , a spring piece 17 is installed between the inner circular surface of the retaining ring 15 and the outer circular surface of the unsealing sleeve 7; the cylinder sleeve 12 is fixedly installed on the outer circular surface of the lower joint 3, and the lower pressure cap 8, connecting pipe 9, seat sleeve 10 and lower piston 11 are fixedly installed in sequence up and down, and the inner circular surface of the lower pressure cap 8 is slid up and down on the outer circular surface of the rubber tube 6, and the lower piston 11 slides up and down and is sealed between the cylinder sleeve 12 and the center tube 1, and a movable tooth 18 is provided on the inner circular surface of the seat sleeve 10 and behind the unsealing sleeve 7, and a seat sealing shear pin 19 is fixedly installed between the unsealing sleeve 7 and the seat sleeve 10, and a water inlet hole 20 is provided on the center tube 1 corresponding to the lower end of the lower piston 11, and a plurality of rubber cylinders 21 arranged up and down are set on the outer circular surface of the rubber tube 6 between the upper pressure cap 5 and the lower pressure cap 8.

[0020] A cleaning mechanism is provided between the upper pressure cap 5 and the central tube 1. The cleaning mechanism includes a well-washing piston 22 that slides up and down and is sealed between the upper pressure cap 5 and the central tube 1. A spring 23 is connected between the well-washing piston 22 and the front end surface of the outer tube. Upper flow holes 24 are circumferentially distributed on the upper pressure cap 5, and lower flow holes 25 are circumferentially distributed on the connecting pipe 9.

[0021] The working principle of this utility model is:

[0022] During the water injection operation, an equal number of the step-by-step layered plugging tools and the bridge-type concentric profile control tools are installed on the oil pipe at intervals, and placed in the casing together with the oil pipe. Then, water is injected through the oil pipe. The injected water enters between the center pipe 1 and the cylinder sleeve 12 through the water inlet hole 20, and pushes the rubber cylinder upward through the lower piston 11, the seat seal sleeve 10, the connecting pipe 9 and the lower pressure cap 8. The seat seal shear pins 19 are cut off, and the rubber cylinder 21 is deformed and tightly expanded on the inner wall of the casing under the squeezing action of the upper pressure cap 5 and the lower pressure cap 8, and the movable teeth 18 on the seat seal sleeve 10 are engaged with the fixed teeth 16 on the retaining ring 15 to achieve plugging. Then, water injection is continued. The water in the oil pipe is injected into the space between the oil pipe and the casing through the bridge-type concentric profile control tool, and is injected into the corresponding formation through the perforation section on the casing.

[0023] During the flushing operation, water is injected between the oil pipe and the casing. The injected water overcomes the elastic force of the spring 23 through the upper flow hole 24 and pushes the well flushing piston 22 upward, enters the central pipe 1 and the upper pressure cap 5, and then enters between the oil pipe and the casing through the lower flow hole 25, and finally enters the interior of the bridge-type concentric profile control tool to clean the bridge-type concentric profile control tool and the oil pipe.

[0024] During the disassembly operation, the center tube 1 is moved upward, and the claws 13 are disengaged from the restraint of the boss 14. Under the action of the elastic force of the rubber tube, the seat sleeve 10 generates a downward thrust on the claws 13. The threads on the rubber tube 6 generate a radially inward lateral component of force on the threads on the claws 13. The claws 13 shrink inward and separate from the rubber tube 6. The unlocking sleeve drives the seat sleeve 10 to move downward, and the rubber tube 21 shrinks and separates from the inner wall of the casing, releasing the blocking state. Finally, the oil pipe and the step-by-step blocking tool are lifted out of the casing.

[0025] The above are only specific embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A step-by-step layered plugging tool comprising a central tube with upper and lower connectors fixedly mounted at the upper and lower ends of the central tube, characterized in that: The outer cylinder, upper pressure cap, rubber tube, unsealing sleeve, lower pressure cap, connecting pipe, seat sleeve, lower piston and cylinder sleeve are mounted on the outer circular surface of the center tube, and the upper joint, outer cylinder, upper pressure cap, rubber tube and seat sleeve are fixedly installed in sequence up and down, and an open clamping ring is clamped on the outer circular surface of the unsealing sleeve, and fixed teeth are provided on the outer circular surface of the clamping ring; the cylinder sleeve is fixedly mounted on the outer circular surface of the lower joint, and the lower pressure cap, connecting pipe, seat sleeve and lower piston are fixedly mounted up and down in sequence, and the inner circular surface of the lower pressure cap is slid up and down on the outer circular surface of the rubber tube, and the lower piston slides up and down and is sealed between the cylinder sleeve and the center tube, and movable teeth are provided on the inner circular surface of the seat sleeve and behind the unsealing sleeve, and a water inlet hole is provided on the center tube corresponding to the lower end of the lower piston, and the rubber cylinder is mounted on the outer circular surface of the rubber tube between the upper pressure cap and the lower pressure cap.

2. The step-by-step layered plugging tool according to claim 1, characterized in that: A locking mechanism is provided between the unsealing sleeve and the seat sleeve.

3. The step-by-step layered plugging tool according to claim 2, characterized in that: The locking mechanism is a sealing shear pin fixedly installed between the unsealing sleeve and the seating sleeve.

4. The step-by-step layered plugging tool according to claim 1, characterized in that: An unlocking mechanism is provided between the central tube and the rubber tube.

5. The step-by-step layered plugging tool according to claim 4, characterized in that: The unlocking mechanism includes claws arranged at the upper end of the unsealing sleeve and distributed circumferentially. The claws are installed on the inner surface of the rubber tube through threads, and a boss is provided on the outer surface of the central tube to fit the inner surface of the claws.

6. The step-by-step layered plugging tool according to claim 1, characterized in that: A cleaning mechanism is provided between the upper pressure cap and the central tube.

7. The step-by-step layered plugging tool according to claim 6, characterized in that: The cleaning mechanism includes a well-washing piston that slides up and down and is sealed between the upper pressure cap and the central tube. A spring is connected between the well-washing piston and the front end surface of the outer tube. The upper pressure cap is provided with circumferentially distributed upper flow holes, and the connecting tube is provided with circumferentially distributed lower flow holes.

8. The step-by-step layered plugging tool according to claim 1, characterized in that: There are multiple rubber cylinders, which are arranged up and down.

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