Grading cementing device for ocean oil and gas well

Abstract

The invention relates to the technical field of staged cementing, in particular to a staged cementing device for an ocean oil and gas well, which comprises a sleeve and an opening plug, a magnetic ring is mounted on the outer side wall of the opening plug, a plurality of switch valve structures are arranged on the inner side of the sleeve, an expansion sealing structure is arranged on the outer side wall of the sleeve, and the oil and gas well wall can be sealed and separated; the opening and closing valve structure comprises a magnetic sheet, the magnetic sheet is connected to the inner wall of the sleeve in a sliding mode, and a blocking column is fixedly connected to one side of the magnetic sheet. Under the pushing force of the internal pressure of the sleeve, the multiple layers of lantern rings are unfolded and pushed to expand preliminarily to improve the efficiency of injecting the expansion liquid, and after injection is completed, the expansion liquid is conveyed to the position of the clamping structure through resetting of the multiple layers of lantern rings, so that permanent sealing is conducted; and meanwhile, mixing of the expansion liquid and the promoting liquid can be promoted in the resetting process.

Description

Technical Field

[0001] This invention relates to the field of graded cementing technology, specifically to a graded cementing device for offshore oil and gas wells. Background Technology

[0002] Staged cementing is generally used to address the challenges of high pressure, low temperature, dynamic environments, and complex well conditions in deep water. It employs a staged cementing method with isolation features. After the first stage of cementing is completed, the opening plug is immediately engaged to activate the injection channel of the isolation unit. By delivering expansion fluids such as epoxy resin into the rubber sleeve of the deep well casing, the staged cementing unit is sealed, providing an anti-interference layered isolation solution for deep water cementing.

[0003] However, during use, it is necessary to deliver an opening plug and a closing plug into the deep well casing. The opening plug opens the circulation hole to release the isolated state of the rubber sleeve and inject expansion fluid into the sleeve. Then, the closing plug permanently seals the channel, so that the temporary isolation of the rubber sleeve is replaced by a structural seal. However, this process is relatively cumbersome, and after the opening plug and closing plug are put in, there is a tendency for them to not be opened or closed, resulting in unstable performance. At the same time, the process of injecting expansion fluid into the rubber sleeve is relatively slow, and after injection, it is necessary to wait for the expansion fluid and the accelerator to mix slowly, which affects the working efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a staged cementing device for offshore oil and gas wells to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a staged cementing device for marine oil and gas wells, comprising a casing and an opening plug, wherein a magnetic ring is installed on the outer wall of the opening plug, a plurality of switching valve structures are provided on the inner side of the casing, and an expansion sealing structure is provided on the outer wall of the casing, which can seal the oil and gas well wall.

[0006] The switching valve structure includes a magnetic sheet slidably connected to the inner wall of the sleeve. A baffle is fixed to one side of the magnetic sheet. An infusion hole is opened on the inner wall of the sleeve, and the groove of the infusion hole can be blocked by the baffle. A locking structure is provided at the lower end of the baffle. A multi-layered collar is provided on the other side of the locking structure, and the multi-layered collar is slidably connected to the outer wall of the sleeve. An inlet hole is opened on the outer wall of the multi-layered collar. A sliding plate is slidably connected to the side of the multi-layered collar away from the sleeve. An air suction groove is opened between the multi-layered collar and the sliding plate. A shaking structure is provided inside the sliding plate, and the shaking structure is interlocked with the expansion sealing structure.

[0007] Preferably, the expansion structure includes a rubber sleeve, which is mounted on the outer wall of the sleeve, and the cavity of the rubber sleeve is in communication with the switching valve structure.

[0008] Preferably, the inner wall of the rubber tube is fixed with a plurality of connecting blocks, and each connecting block can be connected to the wobbling structure on the corresponding position of the slide plate.

[0009] Preferably, the engaging structure includes a push rod, which is fixed to the lower end of the stop post. A spring is sleeved on the outer wall of the push rod and abuts against the stop post. Two locking pieces are provided on the side surface of the push rod and are interlocked with each other.

[0010] Preferably, the locking piece has a connecting rod on the side away from the push rod, and the connecting rod is fixedly connected to the multi-layer collar. A second spring is sleeved on the outer wall of the connecting rod, and the second spring abuts against the sleeve and the multi-layer collar.

[0011] Preferably, the swaying structure includes a counterweight block, which is slidably connected inside the slide plate. A spring is fixedly connected to one side of the counterweight block, and the other end of the spring is fixedly connected to the slide plate. The side surface of the counterweight block is inserted into a connecting block.

[0012] Preferably, the slide plate has a toothed rod 2 that slides up and down inside. One side of the toothed rod 2 is engaged with a gear, and the gear is rotatably connected to the slide plate. One side of the gear is engaged with a toothed rod 1, and the lower end of the toothed rod 1 is inserted into a connecting block.

[0013] Preferably, a piston is fixedly connected to the upper end of the second gear, and a spring is fixedly connected to the lower end of the second gear.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] By pushing the opening plug downwards in the sleeve, as the opening plug passes the magnetic plate, the magnetic plate and magnetic ring attract the opening plug, causing it to slide downwards and move the magnetic plate along with it. This causes the two locking plates to disengage, triggering spring two to release its elastic potential energy and unfold the multi-layer collar. During the unfolding process, the multi-layer collar pushes the sliding plate and the rubber tube, causing the rubber tube to be initially expanded and drawing in some expansion fluid. Then, pressure is used to push the rubber tube to continue expanding, pushing spring two to stretch and store elastic potential energy. After the rubber tube is fully filled, the pressure inside the rubber tube pushes the toothed rod two downwards, causing the connecting block to disengage from the toothed rod one, allowing spring two to release its elastic potential energy and causing the multi-layer collar to contract. The contraction of the multi-layer collar delivers the expansion fluid inside the multi-layer collar to the position of the locking structure. When the expansion fluid cools down, it can more stabilize the locking structure. The permanent locking mechanism, along with the release of elastic potential energy by spring three when the toothed rod is no longer inserted into the counterweight, causes the counterweight to be pulled and moved. After moving a certain distance, it repeatedly shakes, causing the sliding plate to move. This allows the sliding plate to stir the expansion fluid inside the rubber sleeve during the movement of the multi-layered rings. When the rubber sleeve expands to its maximum size, it promotes the mixing of the expansion fluid with the rubber sleeve, causing the expansion fluid on the inner wall of the rubber sleeve to harden rapidly. At this point, the rubber sleeve can no longer transport expansion fluid, causing the opening plug to continue sliding downwards. Simultaneously, the opening plug and the magnetic plate separate, and the stop column is pushed elastically back to its original position by spring one. The expansion fluid fills the lower end of the stop column, thus achieving integrated and rapid sealing of the empty ring between the casing and the oil and gas well wall. At the same time, the sealing and locking of the rubber sleeve is more convenient and stable. Attached Figure Description

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

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the structure of the present invention after the glue tube is removed;

[0019] Figure 3 This is a schematic diagram showing the result after removing the rubber sleeve and tubing according to the present invention;

[0020] Figure 4 For the present invention Figure 2 Enlarged view of point A in the middle;

[0021] Figure 5 For the present invention Figure 3 Enlarged view of point B in the middle;

[0022] Figure 6 This is a schematic diagram of the structure of the multi-layer collar of the present invention;

[0023] Figure 7This is a cross-sectional schematic diagram of the multi-layer collar of the present invention;

[0024] Figure 8 For the present invention Figure 7 Enlarged view of point C in the middle;

[0025] Figure 9 For the present invention Figure 7 Enlarged view of point D in the middle;

[0026] Figure 10 This is a cross-sectional view of the spike wheel of the present invention;

[0027] Figure 11 For the present invention Figure 10 Enlarged view at point E in the middle;

[0028] Figure 12 This is a cross-sectional schematic diagram of the counterweight block of the present invention.

[0029] Explanation of reference numerals in the attached figures:

[0030] 1. Sleeve; 2. Opening plug; 3. Magnetic ring; 4. Stop post; 5. Magnetic plate; 6. Push rod; 7. Locking plate; 8. Spring 1; 9. Multi-layer collar; 10. Spring 2; 11. Connecting rod; 12. Liquid inlet; 13. Slide plate; 14. Rubber sleeve; 15. Counterweight; 16. Spring 3; 17. Connecting block; 18. Gear 1; 19. Gear; 20. Gear 2; 201. Piston; 21. Spring 4; 22. Suction groove; 23. Infusion port. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] See also Figures 1-12 The present invention provides a technical solution: a staged cement injection device for marine oil and gas wells, including a casing 1 and an opening plug 2. A magnetic ring 3 is installed on the outer side wall of the opening plug 2. A plurality of switching valve structures are provided on the inner side of the casing 1. An expansion sealing structure is provided on the outer side wall of the casing 1, which can seal the oil and gas well wall.

[0033] The switching valve structure includes a magnetic sheet 5, which is slidably connected to the inner wall of the sleeve 1. A baffle 4 is fixedly connected to one side of the magnetic sheet 5. An infusion hole 23 is opened on the inner wall of the sleeve 1, and the groove of the infusion hole 23 can be blocked by the baffle 4. A locking structure is provided at the lower end of the baffle 4. A multi-layer collar 9 is provided on the other side of the locking structure, and the multi-layer collar 9 is slidably connected to the outer wall of the sleeve 1. An inlet hole 12 is opened on the outer wall of the multi-layer collar 9. A sliding plate 13 is slidably connected to the side of the multi-layer collar 9 away from the sleeve 1. An air suction groove 22 is opened between the multi-layer collar 9 and the sliding plate 13. A shaking structure is provided inside the sliding plate 13, and the shaking structure and the expansion sealing structure are interlocked.

[0034] In this embodiment, the expansion structure includes a rubber sleeve 14, which is installed on the outer wall of the sleeve 1, and the cavity of the rubber sleeve 14 is in communication with the switch valve structure.

[0035] In this embodiment, a number of connecting blocks 17 are fixedly connected to the inner wall of the rubber tube 14, and each connecting block 17 can be connected to the swaying structure on the corresponding position of the slide plate 13.

[0036] Specifically, when the opening plug 2 slides downwards under pressure inside the sleeve 1, and passes the position of the magnetic piece 5, the magnetic ring 3 and the magnetic piece 5 will be magnetically attracted together. Then, as the magnetic ring 3 continues to slide downwards, the magnetic piece 5 will also slide downwards, and at the same time, the stop post 4 slides downwards to contact the locking structure. (Refer to...) Figure 6 The multi-layered collar 9 is formed by three collars of different sizes being nested together. When the multi-layered collar 9 is pushed by the locking structure, the three collars on the multi-layered collar 9 slide against each other and open. At the same time, suction is applied through the suction groove 22, which pushes the expansion sealing structure away from the sleeve 1 to achieve initial expansion and reduce the expansion time. During the pushing process, the expansion sealing structure also absorbs expansion fluid into the inside of the sleeve 1 through the infusion hole 23. When the rubber sleeve 14 expands to its maximum value, the collars on the multi-layered collar 9 will move to the position shown by the push rod 6 in the figure. In this state, the expansion fluid flowing into the expansion structure will also flow into the interior of the multi-layer collar 9 through the inlet hole 12. When the sleeves on the multi-layer collar 9 are reset, the staggered sleeves will block the inlet hole 12. At the same time, the shaking structure will cause the suction groove 22 between the multi-layer collar 9 and the slide plate 13 to be continuously misaligned, making it difficult for the suction groove 22 to discharge the expansion fluid. As a result, during the subsequent reset of the multi-layer collar 9, the internal expansion fluid cannot flow out and will be pushed into the position of the locking structure installation. When the expansion fluid cools and hardens, it can permanently lock the locking structure.

[0037] In this embodiment, the engaging structure includes a push rod 6, which is fixed to the lower end of the stop post 4. A spring 8 is sleeved on the outer wall of the push rod 6, and the spring 8 abuts against the stop post 4. Two locking pieces 7 are provided on the side surface of the push rod 6, and the two locking pieces 7 are inserted into each other.

[0038] In this embodiment, the side of the locking piece 7 away from the push rod 6 has a built-in connecting rod 11, and the connecting rod 11 is fixedly connected to the multi-layer collar 9. The outer wall of the connecting rod 11 is fitted with a spring 2 10, and the spring 2 10 abuts between the sleeve 1 and the multi-layer collar 9.

[0039] For details, please refer to Figure 9 When the push rod 6 slides down with the stop post 4, the two locking pieces 7 will be misaligned, causing the two locking pieces 7 to disengage. When the two locking pieces 7 disengage, the second spring 10 is in a compressed state, and at this time it will release elastic potential energy, causing the second spring 10 to push the outermost ring of the multi-layer collar 9 to move away from the sleeve 1, and finally causing the three rings on the multi-layer collar 9 to unfold.

[0040] In this embodiment, the swaying structure includes a counterweight 15, which is slidably connected inside the slide plate 13. A spring 16 is fixedly connected to one side of the counterweight 15, and the other end of the spring 16 is fixedly connected to the slide plate 13. The side surface of the counterweight 15 is inserted into the connecting block 17.

[0041] In this embodiment, a second toothed rod 20 is slidably connected to the inside of the slide plate 13. A gear 19 is engaged on one side of the second toothed rod 20, and the gear 19 is rotatably connected to the slide plate 13. A first toothed rod 18 is engaged on one side of the gear 19, and the lower end of the first toothed rod 18 is inserted into the connecting block 17.

[0042] In this embodiment, a piston 201 is fixedly connected to the upper end of the rack 20, and a spring 4 21 is fixedly connected to the lower end of the rack 20.

[0043] Specifically, after the magnetic ring 3 and magnetic plate 5 are attracted, the pressure inside the casing 1 pushes the opening plug 2 downward, which in turn pushes the magnetic plate 5 to its lowest point. At this point, pushing the magnetic plate 5 requires greater pressure, and the spring 8 is also compressed. The excess pressure is then supplied to the inside of the rubber sleeve 14 through the inlet 23, allowing the expansion fluid inside the casing 1 to be delivered to the inside of the rubber sleeve 14, causing the rubber sleeve 14 to expand and fill the well wall to achieve a seal. Then, during the expansion of the rubber sleeve 14, if it expands to its maximum value or completely fills the well wall, the excess pressure will push the piston 201 and the second gear 20 downward, while the spring 21 is compressed. During the downward sliding of the second gear 20, the meshing of the gear 19 causes the first gear 18 to rise. (Refer to...) Figure 11Initially, the toothed rod 18 passes through the counterweight 15 and is inserted into the upper surface of the connecting block 17, preventing both the counterweight 15 and the connecting block 17 from moving. Simultaneously, the rubber cylinder 14 is tightly pressed against the outer surface of the slide plate 13. Then, when the toothed rod 18 is lifted upwards, the connecting block 17 on the rubber cylinder 14 disengages from the toothed rod 18, and the toothed rod 18 no longer restricts the counterweight 15. At this point, the rubber cylinder 14 is filled with expansion fluid, so it will not contract or move. However, during the expansion of the rubber cylinder 14, the spring 10 is stretched and opened, remaining in storage. When the connecting block 17 and the toothed rod 18 are disengaged, the spring 10 releases its elastic restoring force, which in turn causes the multi-layer collar 9 to contract. This causes the expansion fluid inside the multi-layer collar 9 to fill the position of the locking structure. During the reset process of the multi-layer collar 9, the slide plate 13 also resets. This allows the slide plate 13 to push the expansion fluid in the glue tube 14, improving the mixing effect of the accelerator pre-placed in the glue tube 14 and the subsequent flow of expansion fluid. This improves the hardening speed of the glue tube 14 after it is filled with expansion fluid, thus improving work efficiency.

[0044] Working principle: The worker first inserts the opening plug 2 into the sleeve 1. Then, pressure is pumped into the sleeve 1, causing the opening plug 2 to be pushed downwards inside the sleeve 1 due to the pressure. At the same time, some expansion fluid is stored above the opening plug 2. When the opening plug 2 passes the position of the magnetic piece 5, the magnetic piece 5 and the magnetic ring 3 will attract each other. At this time, the opening plug 2 slides downwards, which will drive the magnetic piece 5 to move downwards as well. The magnetic piece 5 then drives the push rod 6, causing the two locking pieces 7 to disengage. At the moment the locking pieces 7 disengage, the spring 10 releases its elastic potential energy, unfolding the multi-layer collar 9. During the unfolding process, the multi-layer collar 9 will push the slide plate 13, which in turn pushes the rubber cylinder 14, thereby causing the rubber cylinder 1 to... 4 is initially expanded. During the expansion process, the rubber sleeve 14 will draw some of the expansion fluid above the opening plug 2 into the interior of the rubber sleeve 14 through the fluid inlet 23. Then, when the pressure is further applied to the inside of the casing 1 to drive the opening plug 2 to slide downward, due to the magnetic attraction between the opening plug 2 and the magnetic plate 5, there is not enough pressure to drive the opening plug 2 to move downward. At this time, the excess pressure will be used to push the rubber sleeve 14 to continue to expand. At the same time, the filling fluid will also flow into the interior of the multi-layer collar 9 until the rubber sleeve 14 expands to completely fill the oil and gas well wall. During the expansion process, it will also push the spring 10 to stretch and store elastic potential energy. Then, after the filling is complete, the pressure inside the rubber sleeve 14 will push the toothed rod 20 to move downward. During the movement of spring 20, it causes rack 18 to slide upwards. As rack 18 slides, connecting block 17 disengages from rack 18, causing spring 20 to release its elastic potential energy. This releases the multi-layer collar 9, causing it to contract. The contraction of the multi-layer collar 9 delivers the expansion fluid inside to the locking structure. Once the expansion fluid cools, it provides a more stable and permanent lock to the locking structure. Simultaneously, when rack 18 is no longer inserted into counterweight 15, spring 36 also releases its elastic potential energy, causing counterweight 15 to be pulled and moved. Since counterweight 15 has a high weight, it will repeatedly sway after moving a certain distance. During the pulling and swaying process of counterweight 15... This will cause the slide plate 13 to move, thereby allowing the slide plate 13 to stir the expansion fluid inside the rubber sleeve 14 during the movement of the multi-layer collar 9. When the rubber sleeve 14 expands to its maximum size, it can promote the mixing of the expansion fluid with the rubber sleeve 14, causing the expansion fluid on the inner wall of the rubber sleeve 14 to harden rapidly. At this time, the rubber sleeve 14 can no longer transport expansion fluid, which will cause the opening plug 2 to continue to slide downward. At the same time, the opening plug 2 and the magnetic plate 5 separate, and the stop column 4 is pushed by the spring 8 to elastically reset. The expansion fluid fills the lower end of the stop column 4, thereby realizing the integrated and rapid sealing of the empty ring between the casing 1 and the oil and gas well wall. At the same time, the sealing and locking of the rubber sleeve 14 is more convenient and stable.

[0045] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A staged cementing device for offshore oil and gas wells, comprising a casing (1) and an opening plug (2), characterized in that: A magnetic ring (3) is installed on the outer wall of the opening plug (2), and a number of switching valve structures are provided on the inner side of the casing (1). An expansion sealing structure is provided on the outer wall of the casing (1), which can seal the oil and gas well wall. The switching valve structure includes a magnetic sheet (5), which is slidably connected to the inner wall of the sleeve (1). A baffle (4) is fixedly connected to one side of the magnetic sheet (5). An infusion hole (23) is opened on the inner wall of the sleeve (1), and the groove of the infusion hole (23) can be blocked by the baffle (4). A locking structure is provided at the lower end of the baffle (4). A multi-layer collar (9) is provided on the other side of the locking structure. The multi-layer collar (9) is slidably connected to the outer wall of the sleeve (1). An inlet hole (12) is opened on the outer wall of the multi-layer collar (9). A sliding plate (13) is slidably connected to the side of the multi-layer collar (9) away from the sleeve (1). An air suction groove (22) is opened between the multi-layer collar (9) and the sliding plate (13). A shaking structure is provided inside the sliding plate (13), and the shaking structure and the expansion sealing structure are interlocked.

2. The staged cementing device for offshore oil and gas wells according to claim 1, characterized in that: The expansion structure includes a rubber sleeve (14), which is installed on the outer wall of the sleeve (1) and the cavity of the rubber sleeve (14) is in communication with the switch valve structure.

3. A staged cementing device for offshore oil and gas wells according to claim 2, characterized in that: The inner wall of the rubber cylinder (14) is fixed with several connecting blocks (17), and each connecting block (17) can be connected to the swaying structure on the corresponding slide plate (13).

4. A staged cementing device for offshore oil and gas wells according to claim 1, characterized in that: The engaging structure includes a push rod (6), which is fixed to the lower end of the stop post (4). A spring (8) is sleeved on the outer side wall of the push rod (6), and the spring (8) abuts against the stop post (4). Two locking pieces (7) are provided on the side surface of the push rod (6), and the two locking pieces (7) are inserted into each other.

5. A staged cementing device for offshore oil and gas wells according to claim 4, characterized in that: The locking piece (7) has a fixed connecting rod (11) on the side away from the push rod (6), and the connecting rod (11) is fixedly connected to the multi-layer collar (9). The outer wall of the connecting rod (11) is fitted with a second spring (10), and the second spring (10) abuts between the sleeve (1) and the multi-layer collar (9).

6. A staged cementing device for offshore oil and gas wells according to claim 3, characterized in that: The swaying structure includes a counterweight (15) which is slidably connected inside the slide plate (13). A spring (16) is fixedly connected to one side of the counterweight (15), and the other end of the spring (16) is fixedly connected to the slide plate (13). The side surface of the counterweight (15) is inserted into the connecting block (17).

7. A staged cementing device for offshore oil and gas wells according to claim 6, characterized in that: The slide plate (13) is internally connected to a toothed rod two (20) that slides up and down. A gear (19) is engaged on one side of the toothed rod two (20), and the gear (19) is rotatably connected to the slide plate (13). A toothed rod one (18) is engaged on one side of the gear (19), and the lower end of the toothed rod one (18) is inserted into the connecting block (17).

8. A staged cementing device for offshore oil and gas wells according to claim 7, characterized in that: A piston (201) is fixedly connected to the upper end of the second rack (20), and a spring (21) is fixedly connected to the lower end of the second rack (20).

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