Acid-resistant soluble bridge plug
By adopting acid-resistant treatment and multi-layer sealing structure in soluble bridge plugs, the problem of bridge plug dissolution in acidic high formation environment is solved, and the long-term pressure bearing and sealing effect in high acid environment is achieved, ensuring oil well sealing stability.
Patent Information
- Application Number
- CN202411626772.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-14
- Publication Date
- 2025-01-10
AI Technical Summary
In a highly acidic stratigraphic environment, existing soluble bridge plugs are prone to dissolve before reaching the designated location and cannot effectively hold pressure and seal, resulting in poor sealing of oil wells.
An acid-resistant soluble bridge plug is designed, using acid-resistant cone sleeves, tile and lead shoes. There are internal teeth on the inner side of the lower part of the cone sleeve, and a vulcanized fixed first soluble rubber layer on the upper end and outside of the cone sleeve. The lock ring is Made of acid-resistant material, it improves sealing performance through a multi-layer sealing structure and elastic telescopic rod, including an outer ring, an inner ring, a rubber ring and a retaining ring, ensuring that the sealing effect is maintained in a high acid environment.
该耐酸可溶桥塞在高酸环境下能够延长承压时间,确保井液密封性,避免提前溶解和扩张,提高了井下工具的稳定性和封堵效果,能够在90℃条件下长时间承受 High pressure difference.
Smart Images
Figure CN119288382A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of downhole tools, and in particular to an acid-resistant soluble bridge plug. Background Art
[0002] The bridge plug was invented in the 1980s. As it has fewer construction procedures, a short cycle, and accurate sealing position, it has been widely used in oil and gas well sealing since its introduction. It has basically replaced the previous cement plug sealing technology and has become the main sealing technology for testing wells to seal the tested layer and conduct upper construction, especially the cable pumping soluble bridge plug perforation and fracturing construction technology. At present, in the development of oil fields, with the increase in the depth of drilling, due to the influence of geological and formation environment and other factors, the soluble bridge plug will be dissolved before reaching the designated location and cannot play the role of pressure-bearing plugging. The acidity in some formation environments is getting higher and higher, especially in acid fracturing construction, so the acid resistance requirements for soluble bridge plugs are getting higher and higher. Therefore, soluble bridge plugs with strong acid resistance are of great significance for oil well plugging. Summary of the invention
[0003] The technical problem to be solved by the present invention is to provide an acid-resistant soluble bridge plug which has strong acid resistance and is suitable for working in a highly acidic formation environment.
[0004] In order to achieve the above object, the technical solution provided by the present invention is:
[0005] The acid-resistant soluble bridge plug comprises a cone sleeve, a slip and a guide shoe whose surfaces are treated with acid resistance. The inner side of the lower part of the cone sleeve is processed with inner teeth. The upper end face of the cone sleeve, the inner edge of the cone sleeve above the inner teeth and the outer side above the outer cone surface of the cone sleeve are vulcanized and fixed with a first soluble rubber layer. A locking ring is installed in the cone sleeve. The locking ring is made of acid-resistant material. The outer edge of the locking ring is processed with outer teeth. The outer teeth of the locking ring are engaged with the inner teeth of the cone sleeve. The lower end of the locking ring is inserted into the upper end of the guide shoe. The upper end of the guide shoe is processed with lower teeth that are engaged with the outer teeth of the locking ring. The upper end, outer side surface and lower end surface of the guide shoe are vulcanized and fixed with a second soluble rubber layer. The upper end of the slip is sleeved on the outer side of the lower end of the cone sleeve. The upper end of the slip is fixedly connected to the cone sleeve by sealing shear nails. The outer side of the lower end of the slip is sleeved with An anti-dissolving outer ring and an anti-dissolving inner ring are fixedly installed on the inner side of the lower end of the slip, the lower ends of the anti-dissolving outer ring, the lower ends of the anti-dissolving inner ring and the lower ends of the slip are all in sealing contact with the second soluble rubber layer, an outer sleeve of the cone sleeve above the slip is provided with a rubber ring, and an outer sleeve of the cone sleeve above the rubber ring is provided with a retaining ring, which blocks the upper end of the rubber ring, the core rod passes through the cone sleeve, the locking ring and the guide shoe, the core rod and the guide shoe are fixedly connected by shear nails, a soluble sealing rubber sleeve is concentrically bonded and fixed to the lower end of the core rod, an annular groove is provided on the outer edge of the upper end of the soluble sealing rubber sleeve, a plurality of elastic telescopic rods are evenly distributed and fixed on the circumference of the inner side of the lower end of the locking ring, the telescopic end of the elastic telescopic rod is in sliding contact with the core rod, and after the annular groove of the soluble sealing rubber sleeve corresponds to the telescopic end of the elastic telescopic rod, the telescopic end of the elastic telescopic rod can be inserted into the annular groove.
[0006] Specifically, a plurality of slip teeth are fixed on the outer side of the slip, and the slip teeth are made of cemented carbide or ceramic.
[0007] Specifically, a spiral spacer ring is provided on the cone sleeve between the lower end of the rubber ring and the upper end of the slip, and the spiral spacer ring blocks the upper end of the slip.
[0008] Specifically, a step is processed on the inner side of the upper end of the guide shoe, the lower end of the lock ring is in sealing contact with the bottom surface of the step through a rubber ring, and the outer side of the lower end of the lock ring is in sealing contact with the side surface of the step.
[0009] Specifically, the locking ring is made of polyacetate material.
[0010] Specifically, the elastic telescopic rod includes an outer sleeve, an inner rod is slidably and sealedly connected to the inner sleeve, one end of the inner rod extends to the outside of the outer sleeve, one end of the inner rod inside the outer sleeve is connected to the outer sleeve through an elastic member, the outer sleeve is fixed at the lower end of the locking ring, and one end of the inner rod outside the outer sleeve is in sliding contact with the outer edge of the core rod.
[0011] Specifically, the outer sleeve and the inner rod are both made of polyacetate material.
[0012] Compared with the prior art, the present invention has the following beneficial effects:
[0013] 1. After the acid-resistant soluble bridge plug is set, the upper end of the lock ring is in sealing contact with the first soluble rubber layer on the inner side of the cone sleeve, the rubber ring is in sealing connection with the inner wall of the casing and the first soluble rubber layer on the outer side of the cone sleeve, the anti-dissolving outer ring is in sealing contact with the inner wall of the casing, the anti-dissolving inner ring is in sealing contact with the lower end of the cone sleeve, and the soluble sealing rubber sleeve is in sealing contact with the inner wall of the guide shoe. The cone sleeve and the guide shoe are in contact with the well fluid only after the first soluble rubber layer and the second soluble rubber layer are dissolved, which can increase the pressure-bearing time of the bridge plug.
[0014] 2. After setting, the rubber ring is sealed and connected with the inner wall of the casing and the first soluble rubber layer on the outer side of the cone sleeve, the anti-dissolving outer ring is in sealing contact with the inner wall of the casing, the anti-dissolving inner ring is in sealing contact with the lower end of the cone sleeve, and the slips are dissolved last, which can further increase the pressure bearing time.
[0015] 3. By setting the spiral spacer, the spiral spacer can block the upper end of the slip to prevent premature sealing.
[0016] 4. The retaining ring can block the rubber ring, so that the rubber ring can be prevented from expanding upward and contacting with the inner wall of the casing when the acid-resistant soluble bridge plug is lowered into the well, thereby ensuring that the acid-resistant soluble bridge plug can be lowered into the well smoothly. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] Figure 1 It is a schematic diagram of the present invention.
[0018] Figure 2This is a schematic diagram of the present invention after removing the core rod and the soluble sealing rubber sleeve.
[0019] Figure 3 It is a schematic diagram of the present invention after sealing.
[0020] Figure 4 It is a cross-sectional view of the elastic telescopic rod.
[0021] The names of the parts in the accompanying drawings are: 1. cone sleeve, 2. retaining ring, 3. rubber ring, 4. spiral spacer ring, 5. setting shear pins, 6. slips, 7. slip teeth, 8. locking ring, 9. anti-dissolving inner ring, 10. anti-dissolving outer ring, 11. guide shoe, 12. release shear pins, 13. core rod, 14. soluble sealing rubber sleeve, 15. ring groove, 16. elastic telescopic rod, 17. first soluble rubber layer, 18. second soluble rubber layer, 19. rubber ring, 20. casing, 21. outer sleeve, 22. inner rod, 23. elastic part. DETAILED DESCRIPTION
[0022] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.
[0023] like Figure 1-Figure 4 As shown, the acid-resistant soluble bridge plug includes a cone sleeve 1, a slip 6 and a guide shoe 11, the inner side of the lower part of the cone sleeve 1 is processed with internal teeth, and a first soluble rubber layer 17 is vulcanized and fixed on the upper end surface of the cone sleeve 1, the inner edge of the cone sleeve 1 above the internal teeth, and the outer surface above the outer cone surface of the cone sleeve 1.
[0024] A lock ring 8 is installed in the cone sleeve 1, and the lock ring 8 is made of acid-resistant material. Specifically, the lock ring 8 is made of polyacetic acid alcohol material.
[0025] The outer edge of the lock ring 8 is processed with external teeth, and the external teeth of the lock ring 8 are engaged with the internal teeth of the cone sleeve 1. The lower end of the lock ring 8 is inserted into the upper end of the guide shoe 11, and the upper end of the guide shoe 11 is processed with lower teeth that are engaged with the external teeth of the lock ring 8.
[0026] The inner side of the upper end of the guide shoe 11 is processed with a step, the lower end of the lock ring 8 is in sealing contact with the bottom surface of the step through the rubber ring 19, and the outer side of the lower end of the lock ring 8 is in sealing contact with the side surface of the step.
[0027] A second soluble rubber layer 18 is fixed to the upper end surface, the outer side surface and the lower end surface of the guide shoe 11 by vulcanization.
[0028] A plurality of slip teeth 7 are fixed on the outer side of the slip 6, and the slip teeth 7 are made of hard alloy or ceramic. The upper end of the slip 6 is sleeved on the outer side of the lower end of the cone sleeve 1, and the upper end of the slip 6 is fixedly connected to the cone sleeve 1 through the setting shear nails 5.
[0029] An anti-dissolving outer ring 10 is sleeved on the outer side of the lower end of the slip 6, and an anti-dissolving inner ring 9 is fixedly installed on the inner side of the lower end of the slip 6. The lower ends of the anti-dissolving outer ring 10, the anti-dissolving inner ring 9 and the slip 6 are all in sealing contact with the second soluble rubber layer 18.
[0030] A rubber ring 3 is sleeved on the outer side of the cone sleeve 1 above the slip 6 , and a retaining ring 2 is sleeved on the outer side of the cone sleeve 1 above the rubber ring 3 . The retaining ring 2 blocks the upper end of the rubber ring 3 .
[0031] A spiral spacer ring 4 is sleeved on the cone sleeve 1 between the lower end of the rubber ring 3 and the upper end of the slip 6 , and the spiral spacer ring 4 blocks the upper end of the slip 6 .
[0032] The core rod 13 passes through the cone sleeve 1 , the locking ring 8 and the guide shoe 11 , and the core rod 13 is fixedly connected to the guide shoe 11 by means of a shear nail 12 .
[0033] A soluble sealing rubber sleeve 14 is concentrically bonded and fixed to the lower end of the core rod 13, and an annular groove 15 is provided on the outer edge of the upper end of the soluble sealing rubber sleeve 14. A plurality of elastic telescopic rods 16 are evenly distributed and fixed on the inner circumference of the lower end of the locking ring 8. The telescopic ends of the elastic telescopic rods 16 are in sliding contact with the core rod 13. After the annular groove 15 of the soluble sealing rubber sleeve 14 corresponds to the telescopic end of the elastic telescopic rod 16, the telescopic end of the elastic telescopic rod 16 can be inserted into the annular groove 15.
[0034] The elastic telescopic rod 16 includes an outer sleeve 21, and an inner rod 22 is slidably and sealedly connected inside the outer sleeve 21. One end of the inner rod 22 extends to the outside of the outer sleeve 21. One end of the inner rod 22 inside the outer sleeve 21 is connected to the outer sleeve 21 through an elastic member 23. The outer sleeve 21 is fixed inside the lower end of the locking ring 8, and one end of the inner rod 22 outside the outer sleeve 21 is in sliding contact with the outer edge of the core rod 13.
[0035] The outer sleeve 21 and the inner rod 22 are both made of polyacetate material.
[0036] When in use, lower the acid-resistant soluble bridge plug to the designed depth. When setting, pull the core rod 13 upward, and the soluble sealing rubber sleeve 14 moves upward accordingly. The lower end of the pipe column blocks the upper end of the cone sleeve 1. When the core rod 13 pulls the guide shoe 11 upward, the locking ring 8 moves upward in the cone sleeve 1 and the outer teeth of the locking ring 8 engage with the inner teeth of the cone sleeve 1. When the guide shoe 11 moves upward, the slip 6 moves upward accordingly and continues to expand under the action of the cone sleeve 1. When the slip 6 expands, the spiral spacer ring 4 expands upward, the rubber ring 3 expands upward, and the retaining ring 2 is squeezed and broken by the rubber ring 3. When the slip teeth 7 of the slip 6 are inserted into the casing 20, continue to pull the core rod 13 upward, and after the hand-release shear nails 12 are cut off, the setting of the acid-resistant soluble bridge plug is completed.
[0037] When the soluble sealing rubber sleeve 14 goes up with the core rod 13, after the inner rod 22 corresponds to the annular groove 15, the inner rod 22 enters the annular groove 15 under the elastic force of the elastic member 23, and after the core rod 13 is pulled out, the soluble sealing rubber sleeve 14 seals the inner wall of the guide shoe 11. At this time, the upper end of the lock ring 8 is in sealing contact with the first soluble rubber layer 17 on the inner side of the cone sleeve 1, the rubber ring 3 is in sealing connection with the inner wall of the casing 20 and the first soluble rubber layer 17 on the outer side of the cone sleeve 1, the anti-dissolving outer ring 10 is in sealing contact with the inner wall of the casing 20, the anti-dissolving inner ring 9 is in sealing contact with the lower end of the cone sleeve 1, and the soluble sealing rubber sleeve 14 is in sealing contact with the inner wall of the guide shoe 11. When the first soluble rubber layer 17 and the second soluble rubber layer 18 are dissolved, the cone sleeve 1 and the guide shoe 11 are in contact with the well fluid, which can increase the pressure bearing time of the bridge plug.
[0038] After setting, the rubber ring 3 is partially sealed and connected to the inner wall of the casing 20 and the first soluble rubber layer 17 on the outer side of the cone sleeve 1, the anti-dissolving outer ring 10 is in sealing contact with the inner wall of the casing 20, the anti-dissolving inner ring 9 is in sealing contact with the lower end of the cone sleeve 1, and the slip 6 is dissolved last, which can further increase the pressure bearing time.
[0039] By arranging the spiral spacer ring 4, the spiral spacer ring 4 can block the upper end of the slip 6 to prevent premature setting.
[0040] The retaining ring 2 can block the rubber ring 3, and when the acid-resistant soluble bridge plug is lowered into the well, the rubber ring 3 can be prevented from expanding upward and contacting the inner wall of the casing 20, thereby ensuring that the acid-resistant soluble bridge plug can be lowered into the well smoothly.
[0041] The acid-resistant soluble bridge plug can withstand a pressure difference of 50MPa≥24h and a pressure difference of 80MPa≥15min in a 1% potassium chloride standard solution at 90℃. It can withstand a pressure difference of 70MPa≥6h in a 20% hydrochloric acid standard solution at 90℃.
[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. An acid-resistant soluble bridge plug, comprising a cone sleeve (1), a slip (6) and a guide shoe (11) with a surface treated with acid resistance, characterized in that: The inner side of the lower part of the cone sleeve (1) is processed with inner teeth, and a first soluble rubber layer (17) is vulcanized and fixed on the upper end surface of the cone sleeve (1), the inner edge of the cone sleeve (1) above the inner teeth, and the outer surface above the outer cone surface of the cone sleeve (1). A lock ring (8) is installed in the cone sleeve (1), and the lock ring (8) is made of acid-resistant material. The outer edge of the lock ring (8) is processed with outer teeth. The outer teeth of the lock ring (8) are engaged with the inner teeth of the cone sleeve (1). The lower end of the lock ring (8) is inserted into the upper end of the guide shoe (11). The upper end of the shoe (11) is processed with lower teeth that engage with the outer teeth of the lock ring (8); the upper end surface, outer side surface and lower end surface of the guide shoe (11) are vulcanized and fixed with a second soluble rubber layer (18); the upper end of the slip (6) is sleeved on the outer side of the lower end of the cone sleeve (1); the upper end of the slip (6) is fixedly connected to the cone sleeve (1) through a sealing shear nail (5); the outer side of the lower end of the slip (6) is sleeved with a dissolving-resistant outer ring (10); the inner side of the lower end of the slip (6) is fixedly installed with a dissolving-resistant inner ring (9); the dissolving-resistant outer ring (10) The lower end, the lower end of the anti-dissolving inner ring (9) and the lower end of the slip (6) are all in sealing contact with the second soluble rubber layer (18); the outer side of the cone sleeve (1) above the slip (6) is provided with a rubber ring (3); the outer side of the cone sleeve (1) above the rubber ring (3) is provided with a retaining ring (2); the retaining ring (2) blocks the upper end of the rubber ring (3); the core rod (13) passes through the cone sleeve (1), the locking ring (8) and the guide shoe (11); the core rod (13) and the guide shoe (11) are fixedly connected by a shear nail (12 ...; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod (13) and the guide shoe (11) are fixedly connected; the core rod ( A soluble sealing rubber sleeve (14) is coaxially bonded and fixed to the lower end of the locking ring (8), an annular groove (15) is provided on the outer edge of the upper end of the soluble sealing rubber sleeve (14), and a plurality of elastic telescopic rods (16) are evenly distributed and fixed on the inner circumference of the lower end of the locking ring (8), and the telescopic ends of the elastic telescopic rods (16) are in sliding contact with the core rod (13). After the annular groove (15) of the soluble sealing rubber sleeve (14) corresponds to the telescopic end of the elastic telescopic rod (16), the telescopic end of the elastic telescopic rod (16) can be inserted into the annular groove (15).
2. The acid-resistant soluble bridge plug according to claim 1, characterized in that: A plurality of slip teeth (7) are fixed on the outer side of the slip (6), and the slip teeth (7) are made of hard alloy or ceramic material.
3. The acid-resistant soluble bridge plug according to claim 1, characterized in that: A spiral spacer ring (4) is sleeved on the cone sleeve (1) between the lower end of the rubber ring (3) and the upper end of the slip (6), and the spiral spacer ring (4) blocks the upper end of the slip (6).
4. The acid-resistant soluble bridge plug according to claim 1, characterized in that: The inner side of the upper end of the guide shoe (11) is processed with a step, the lower end of the lock ring (8) is in sealing contact with the bottom surface of the step through a rubber ring (19), and the outer side of the lower end of the lock ring (8) is in sealing contact with the side surface of the step.
5. The acid-resistant soluble bridge plug according to claim 1, characterized in that: The locking ring (8) is made of polyacetate material.
6. The acid-resistant soluble bridge plug according to claim 1, characterized in that: The elastic telescopic rod (16) comprises an outer sleeve (21), an inner rod (22) is slidably and sealingly connected inside the outer sleeve (21), one end of the inner rod (22) extends to the outside of the outer sleeve (21), one end of the inner rod (22) inside the outer sleeve (21) is connected to the outer sleeve (21) through an elastic member (23), the outer sleeve (21) is fixed inside the lower end of the locking ring (8), and one end of the inner rod (22) outside the outer sleeve (21) is in sliding contact with the outer edge of the core rod (13).
7. The acid-resistant soluble bridge plug according to claim 6, characterized in that: The outer sleeve (21) and the inner rod (22) are both made of polyacetate material.