An infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields

Abstract

The present invention discloses an infinite-stage, full-bore switchable casing sleeve packer for oil fields, comprising: an upper joint, an upper center pipe, a connecting sleeve, a balancing valve, an upper cap, a rubber cylinder, a lower cap, a limit cap, a cone, a lower center pipe, a slip, a slip seat, a positioning pin, a trough, a friction block, a retaining ring, a locking cap, a track-changing mechanism, and a guide lower joint. The present invention realizes casing sleeve switching and bottom sealing fracturing in one trip of the tubing string. By adopting fuzzy positioning, it solves the problem that the casing sleeve switching tool and the fracturing packer cannot accurately locate the casing sleeve. Through the design of special tracks and friction blocks, it avoids the problem of the traditional Y211 fracturing packer being mistakenly set when the tubing string is raised and lowered. The present invention can be used as a sleeve opening and fracturing tool, and can also be used as a sleeve closing tool after simple adjustment. The operation is simple, and the on-site operation cost and time cost are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield downhole tools, in particular to an infinite-stage full-diameter switchable casing sliding sleeve switch packer for oilfields. Background Art

[0002] The unlimited-stage, full-bore, openable casing sleeve is an essential tool for staged fracturing in oil fields. Currently, the casing sleeve must be lowered into the well along with the casing for normal cementing. After cementing, specialized tools are used to locate the target sleeve, open it, and then remove the opening tool string. The fracturing packer is then lowered and located below the target sleeve before fracturing can begin. Traditional opening tools and fracturing packers often struggle to accurately locate the sleeve, and multiple string trips are required to open the sleeve and set the fracturing packer, making the operation complex and resulting in a low success rate. Summary of the Invention

[0003] The purpose of the present invention is to provide an infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields, which avoids the problem of traditional Y211 fracturing packers being mistakenly set when raising and lowering the tubing string. The invention can be used as a sliding sleeve opening and fracturing tool, and can also be used as a sliding sleeve closing tool after simple adjustment. The operation is simple, and the on-site operation cost and time cost are reduced.

[0004] To achieve the above-mentioned object, the present invention adopts the following technical solution: an infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields, comprising: an upper joint, an upper center pipe, a connecting sleeve, a balancing valve, an upper and lower cap, a rubber sleeve, a lower and lower cap, a limiting cap, a cone, a lower center pipe, slips, a slip seat, a positioning pin, a trough, a friction block, a retaining ring, a locking cap, a track-changing mechanism and a guiding lower joint, wherein the upper joint, the upper center pipe and the balancing valve are connected as a whole through threads and are movably connected to the connecting sleeve, the connecting sleeve, the upper and lower cap are connected as a whole through threads, the lower and lower cap is connected as a whole through threads, and is sleeved on the lower center pipe together with the rubber sleeve and is limited by the limiting cap;

[0005] The lower central tube is provided with two long rails, two short rails and two positioning rails. One end of the lower central tube is provided with four rail end slots, which are staggered at a certain angle with the long rails and the short rails.

[0006] The friction block is embedded in the trough body, and the two ends of the friction block are fixed by retaining rings. The slip seat is connected to the trough body through a threaded connection. A positioning pin is installed inside the slip seat, and the positioning pin is embedded in the positioning track on the lower center tube; the slip is embedded in the slip seat and supported by a spring;

[0007] The track-changing mechanism includes a swivel and a track-changing pin. The track-changing pin is inside the swivel. The swivel is sleeved on the lower center tube. The outer layer is wrapped by a locking cap. The locking cap is threadedly connected to the slot body. The guide lower joint is threadedly connected to the lower center tube.

[0008] Preferably, the balancing valve is provided with sealing material, and the balancing valve and the lower center pipe are in sealing cooperation.

[0009] Preferably, the long track and the short track on the lower central tube have the same total length, and the short track is divided into two parts, an upper part and an lower part, by a breakpoint in the middle.

[0010] Preferably, the friction block is divided into a positioning friction block and a common friction block. The positioning friction block has a protrusion in the middle as a positioning pin, and the friction block is supported by a spring inside.

[0011] Preferably, the trough body is sleeved on the central tube and slides up and down outside the central tube.

[0012] Preferably, one end of the slip has a conical surface with a certain angle, the angle of the conical surface matches the angle of the cone, and after the slip contacts the cone, the slip can expand radially in the slip seat.

[0013] Preferably, one end of the positioning pin is embedded in the positioning track on the lower central tube.

[0014] Beneficial effects

[0015] The present invention realizes casing sleeve opening and closing and bottom seal fracturing with one trip of tubing, adopts fuzzy positioning, solves the pain point that casing sleeve opening and closing tools and fracturing packers cannot accurately locate casing sleeves, and avoids the problem of traditional Y211 fracturing packers being incorrectly sealed when raising and lowering tubing through the design of special tracks and friction blocks. The present invention can be used as a sleeve opening and fracturing tool, and can also be used as a sleeve closing tool after simple adjustment, which simplifies operation and reduces on-site operation costs and time costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments;

[0017] Figure 1 This is a structural schematic diagram of an infinite-stage, full-diameter switchable casing sliding sleeve switch packer for oil fields according to the present invention;

[0018] Figure 2 This is a schematic diagram of the lower central pipe of an infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields according to the present invention;

[0019] Figure 3 This is a diagram showing a first specific embodiment of an infinite-stage, full-diameter switchable casing sliding sleeve switch packer for oil fields according to the present invention;

[0020] Figure 4 This is a diagram showing a first specific embodiment of an infinite-stage, full-diameter switchable casing sliding sleeve switch packer for oil fields according to the present invention.

[0021] Legend:

[0022] 1. Upper joint; 2. Upper center tube; 3. Connecting sleeve; 4. Balancing valve; 5. Upper joint cap; 6. Rubber cylinder; 7. Lower joint cap; 8. Limit cap; 9. Cone; 10. Lower center tube; 11. Slip; 12. Slip seat; 13. Positioning pin; 14. Trough; 15. Retaining ring; 16. Locking cap; 17. Track changing mechanism; 18. Guide lower joint; 19. Long track; 1901, Track changing bottom dead center; 20. Positioning track; 21. Short track; 2101, Short track dead point; 22. Inner sleeve; 23. Capture groove; 24. Friction block. DETAILED DESCRIPTION

[0023] This section will describe in detail the specific embodiments of the present invention. The preferred embodiments of the present invention are shown in the accompanying drawings. The purpose of the accompanying drawings is to supplement the description of the text part of the specification with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present invention, but it should not be understood as a limitation on the scope of protection of the present invention.

[0024] Reference Figure 1-4 The embodiment of the present invention is an infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields, which includes: an upper joint 1, an upper central pipe 2, a connecting sleeve 3, a balancing valve 4, an upper cap 5, a rubber cylinder 6, a lower cap 7, a limit cap 8, a cone 9, a lower central pipe 10, a slip 11, a slip seat 12, a positioning pin 13, a trough 14, a friction block 24, a retaining ring 15, a locking cap 16, a track-changing mechanism 17 and a guide lower joint 18, wherein the upper joint 1 is used to connect with the tubing string, and an adapter can be used to select whether to use ordinary tubing or continuous tubing; the upper central pipe 2, the connecting sleeve 3, and the balancing valve 4 form a channel with balanced internal and external pressures to ensure that it is not affected by the downhole pressure when going down the well, and at the same time provide a sand adding channel during fracturing and sand adding; the upper cap 5, the lower cap 7, The rubber cylinder 6, cone 9 and limit cap 8 are the sealing components of the packer, which realize the sealing of the oil casing annulus after the packer is set; the slip 11 and slip seat 12 are the packer anchoring components, which provide support for the compression of the rubber cylinder 6; the positioning pin 13, friction block 24, groove body 14, retaining ring 15, locking cap 16 and track changing mechanism 17 are the packer track changing components, which realize the switching between the packer tracks through the friction between the friction block 24 and the casing wall, and also straighten the packer. Among them, the positioning pin 13 is embedded in the positioning track 20 of the lower center pipe 10 to ensure that the friction block 24 will not rotate during the track changing process; the guide lower joint 18 serves as the packer guide head, which provides guidance for the packer during the downhole process, and can also connect some tools such as oil pipes as tubing counterweights.

[0025] The upper joint 1, the upper center tube 2, and the balancing valve 4 are connected as a whole through threads and are movably connected to the connecting sleeve 3. The connecting sleeve 3, the upper cap 5 and the lower center tube 10 are connected as a whole through threads. The lower cap 7 and the cone 9 are connected as a whole through threads and are mounted on the lower center tube 10 together with the rubber cylinder 6 and are limited by the limit cap 8.

[0026] There are two long rails 19, two short rails 21 and two positioning rails 20 on the lower central tube 10. One end of the lower central tube 10 is provided with four rail terminal grooves, which are staggered at a certain angle with the long rails 19 and the short rails 21.

[0027] The friction block 24 is embedded in the groove body 14, and the two ends of the friction block 24 are fixed by the retaining ring 15. The friction block 24 is divided into a positioning friction block 24 and a common friction block 24. The positioning friction block 24 has a protrusion in the middle as a positioning pin, and the friction block 24 is supported by a spring. The cava seat 12 is connected to the groove body 14 through a threaded connection. The interior of the cava seat 12 is equipped with a positioning pin 13, and the positioning pin 13 is embedded in the positioning track 20 on the lower center tube 10; the cava 11 is embedded in the cava seat 12 and supported by a spring; the groove body 14 is sleeved on the center tube and slides up and down on the outside of the center tube.

[0028] The track changing mechanism 17 includes a swivel and a track changing pin. The track changing pin is inside the swivel, and the swivel is sleeved on the lower center tube 10. The outer layer is wrapped by the locking cap 16. The locking cap 16 is threadedly connected to the trough body 14. The guide lower joint 18 is threadedly connected to the lower center tube 10. The long track 19 and the short track 21 on the lower center tube 10 have the same total length. The short track 21 is interrupted by a breakpoint in the middle and is divided into two parts: the short track dead point 2101 and the track changing bottom dead point 1901. One end of the slip 11 has a conical surface with a certain angle, and the angle of the conical surface matches the angle of the cone 9. After the slip 11 contacts the cone 9, the slip 11 can expand radially in the slip seat 12. One end of the positioning pin 13 is embedded in the positioning track 20 on the lower center tube 10. The balancing valve 4 is provided with sealing material, and the balancing valve 4 and the lower center tube 10 are sealed.

[0029] Working principle: The function of the long and short tracks of this tool is that when the track-changing pin of the track-changing mechanism is on the short track, the slips will not contact the cone, the slips will not expand and anchor on the casing, and will not provide support for the rubber sleeve, the rubber sleeve will not expand, and the packer will not be set; when the track-changing pin of the track-changing mechanism is on the long track, the slips can contact the cone, and with the support of the cone, the slips will expand and anchor on the casing, the rubber sleeve will be compressed, and the packer will be set.

[0030] When the tool is lowered into the well, the track-changing mechanism is at the bottom dead center of the short track. After the tool enters the casing, the friction block compresses, and the positioning pins of the friction block extend into the long and short tracks of the lower central pipe. The friction block's positioning pins and the track-changing mechanism's track-changing pins now engage at either end of the short track's breakpoint, locking the central pipe. At this point, regardless of whether the tubing string is raised or lowered, the present invention will not cause track changes. When the present invention passes through the target casing sleeve and is lifted upward, the friction block springs open at the sleeve's capture groove, releasing the central tube. The track-changing mechanism moves to the lower central tube's track-changing bottom dead center. The tubing string is then lowered again, and the track-changing pin switches from the short track to the long track. The slips then contact the cone, expanding and supported by the cone. The slips capture the sleeve's opening groove and anchor to the sleeve's inner sleeve. The cone and lower cap remain stationary. The upper joint, upper central tube, balancing valve, connecting sleeve, upper cap, and lower central tube descend as a whole, compressing the rubber sleeve and setting the packer. Further lowering is performed, and under the action of gravity, the packer drives the inner sleeve of the casing sleeve downward, releasing the casing sleeve. At this point, fracturing operations can proceed directly. To release the seal, the tubing string is lifted, causing the upper joint, upper central tube, balancing valve, connecting sleeve, upper cap, and lower central tube to ascend. The rubber sleeve returns to its original position, releasing the packer. Under the action of the limiting cap, the lower cap and cone move upward, the slips, slip seat and trough body are immobilized under the friction of the friction block, the slips separate from the cone and lose support, and the slips are retracted. The entire invention is dragged away from the casing sleeve to another casing sleeve or out of the wellhead.

[0031] To close the sleeve, the present invention is installed in the tubing string in reverse. The track-changing mechanism is lowered into the wellbore on the short track. During the lowering process, the track-changing pin moves to the track-changing bottom dead center. When the present invention is lowered a short distance below the casing sleeve, the tubing string is lifted. The track-changing mechanism switches to the long track, the slip cones engage, and the slips expand and capture the closing grooves of the casing sleeve, closing the sleeve. The tubing string is now lowered below the sleeve. During this process, the track-changing mechanism switches to the short track, and the slip cones do not engage or expand. The tool can be moved to another sleeve or pulled out to the wellhead.

[0032] In this embodiment, the tool only needs to be at a fuzzy distance above and below the casing sliding sleeve, so the present invention realizes fuzzy positioning and switching the sliding sleeve.

[0033] The embodiments of the present invention are described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Various changes can be made within the scope of knowledge possessed by ordinary technicians in the relevant technical field without departing from the scope of the present invention.

Claims

1. An infinite-stage full-diameter switchable casing sliding sleeve switch packer for oil fields, characterized in that: include: An upper joint (1), an upper center tube (2), a connecting sleeve (3), a balancing valve (4), an upper cap (5), a rubber cylinder (6), a lower cap (7), a limiting cap (8), a cone (9), a lower center tube (10), a slip (11), a slip seat (12), a positioning pin (13), a trough (14), a friction block (24), a retaining ring (15), a locking cap (16), a track-changing mechanism (17) and a guide lower joint (18), wherein the upper joint (1), the upper center tube (2) and the balancing valve (4) are connected as a whole through threads and are movably connected to the connecting sleeve (3), the connecting sleeve (3), the upper cap (5) and the lower center tube (10) are connected as a whole through threads, the lower cap (7) and the cone (9) are connected as a whole through threads, are sleeved on the lower center tube (10) together with the rubber cylinder (6), and are limited by the limiting cap (8); The lower central tube (10) has two long rails (19), two short rails (21) and two positioning rails (20), and one end of the lower central tube (10) has four rail end slots, which are staggered at a certain angle with the long rails (19) and the short rails (21); The friction block (24) is embedded in the trough body (14), and both ends of the friction block (24) are fixed by retaining rings (15). The slip seat (12) and the trough body (14) are connected by threads. A positioning pin (13) is installed inside the slip seat (12), and the positioning pin (13) is embedded in the positioning track (20) on the lower center tube (10); the slip (11) is embedded in the slip seat (12) and is supported by a spring; The track-changing mechanism (17) comprises a swivel and a track-changing pin, wherein the track-changing pin is inside the swivel, the swivel is sleeved on the lower central tube (10), and the outer layer is wrapped by a locking cap (16), the locking cap (16) is connected to the trough body (14) by a thread, and the guide lower joint (18) is threadedly connected to the lower central tube (10); the balancing valve (4) is provided with a sealing material, and the balancing valve (4) and the lower central tube (10) are in a sealed fit; the long track (19) and the short track (21) on the lower central tube (10) have the same total length, and the short track (21) is divided into upper and lower parts by a breakpoint in the middle.

2. The infinite-stage full-bore switchable casing sliding sleeve switch packer for oil fields according to claim 1, characterized in that: The friction block (24) is divided into a positioning friction block (24) and a common friction block (24). The positioning friction block (24) has a protrusion in the middle as a positioning pin, and the friction block (24) is supported by a spring inside.

3. The infinite-stage full-bore switchable casing sliding sleeve switch packer for oil fields according to claim 1, characterized in that: The trough body (14) is sleeved on the central tube and slides up and down on the outside of the central tube.

4. The infinite-stage full-bore switchable casing sliding sleeve switch packer for oil fields according to claim 1, characterized in that: One end of the slip (11) has a conical surface with a certain angle, the angle of the conical surface matches the angle of the cone (9), and after the slip (11) contacts the cone (9), the slip (11) can expand radially in the slip seat (12).

5. The infinite-stage full-bore switchable casing sliding sleeve switch packer for oil fields according to claim 1, characterized in that: One end of the positioning pin (13) is embedded in the positioning track (20) on the lower center tube (10).

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