Double-clamping single-cylinder bridge plug capable of preventing setting deviation
By setting lateral guides between the bridge plug slips and adding return holes to the release head, the problems of unstable bridge plug setting and low return efficiency were solved, achieving stability and efficient return in downhole operations.
Patent Information
- Application Number
- CN202520037098.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-08
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2035-01-08
AI Technical Summary
Existing bridge plugs are prone to uneven expansion of the slips and insufficient anchoring force during the setting process, making them unable to withstand high-pressure downhole operations. Furthermore, their fluid return efficiency is low, affecting construction progress and costs.
A double-clamp single-cylinder bridge plug is designed to prevent seat misalignment. By setting lateral guides between the slip segments and adding a return hole at the drop end, the slips are ensured to expand evenly and the return efficiency is improved.
This achieved stability and anchoring force in the bridge plug setting, improved the efficiency of backflow fluid, and reduced construction costs and time.
Smart Images
Figure CN223577889U_ABST
Abstract
Description
Technical Field
[0001] This application relates to a double-clamp single-cylinder bridge plug for preventing setting misalignment, applicable to the technical field of downhole plugging tools. Background Technology
[0002] Currently, all bridge plugs used in major oil and gas fields require successful setting to ensure the smooth operation of subsequent fracturing work. Furthermore, flowback is performed after fracturing. Successful bridge plug setting and flowback are crucial aspects of oil and gas extraction, directly impacting the extraction progress. Therefore, adjusting and optimizing the bridge plug structure to ensure stability and improve flowback efficiency is of great significance to oil and gas extraction. Existing technologies have the following drawbacks: uneven expansion of the setting slips, insufficient anchoring force, and inability to withstand high-pressure operating environments.
[0003] On one hand, the conventional dropper serves to connect to the central tube and fix the various bridge plug components located on it. Simultaneously, the threaded connection at the dropper's central hole engages with the setting rod to provide setting force. The slips are gradually expanded as the cone-shaped surface moves from a small diameter to a large diameter. Each slip has a high probability of uneven expansion and cracking. Unevenly expanded slips are also highly likely to remain unevenly expanded during subsequent movement until they adhere tightly to the casing inner wall. In this state, slip setting deviations occur, making it difficult to withstand the high-pressure downhole environment. This leads to bridge plug slippage during pressurization, resulting in insufficient pressure drop. In severe cases, the bridge plug may slip off and fall into the ground, significantly impacting construction progress and causing high construction costs.
[0004] On the other hand, the discharge of flowback fluid from conventional bridge plugs is mainly achieved through the flow-back operation via the central bore of the dropper. Therefore, the main factor affecting flowback efficiency is determined by the bridge plug's bore diameter. However, the inner diameter of the dropper is limited by many other operating parameters and cannot be adjusted. For example, the setting force: the larger the normal bore diameter, the larger the diameter of the dropper thread, and the greater the dropper force, which is detrimental to downhole operations; the casing diameter: the bridge plug's own diameter is influenced by commonly used oil casing specifications during bridge plug design and is proportional to the oil casing specifications. Therefore, with a fixed outer diameter, increasing the inner diameter is also limited. In summary, optimizing the bore diameter is not an effective way to increase flowback efficiency. The high cost of the flowback process is due to the lack of structural design to improve flowback efficiency, resulting in low flowback efficiency. Utility Model Content
[0005] The purpose of this application is to design a double-clamp single-cylinder bridge plug to prevent setting misalignment. It can not only solve the problem of uneven expansion and cracking during the expansion of the slip, but also make the backflow efficiency higher and more effective.
[0006] According to this application, a double-clamp single-cylinder bridge plug for preventing setting misalignment is characterized by comprising a central tube and a dropper head, the lower end of the central tube being connected to the dropper head, and two sets of clamping assemblies being provided between the central tube and the dropper head. The two sets of clamping assemblies include an upper clamping assembly and a lower clamping assembly. The upper clamping assembly includes an upper slip and an upper cone, with the upper slip fitted over the upper cone. The lower clamping assembly includes a lower slip and a lower cone, with the lower slip fitted over the lower cone. The upper slip and the lower slip are each provided with multiple slip flaps, and a separating groove is provided between the multiple slip flaps. A lateral guide is provided within the separating groove.
[0007] The central tube has an upper locking connector on the side away from the dropper head. The central tube and the upper locking connector can be connected by threads or by a mounting base. A rubber sleeve can be provided between the two locking assemblies. The upper locking assembly is located between the upper locking connector and the rubber sleeve, and the lower locking assembly is located between the rubber sleeve and the dropper head. An upper protective cup and a lower protective cup can also be provided on both sides of the rubber sleeve, respectively. The upper locking connector and the upper cone are located between the upper locking connector and the upper protective cup, and the lower locking connector and the upper cone are located between the upper locking connector and the upper protective cup. The lower cone is disposed between the lower protective cup and the dropper head; the upper locking assembly and the lower locking assembly can be mirror images of the rubber sleeve; the lateral guide can be respectively mounted on the upper cone and the lower cone; the upper slip connecting part is provided with a first threaded hole, and the central tube is provided with a second threaded hole, the first threaded hole and the second threaded hole are aligned and a shear pin can be inserted to lock them; the end of the lower slip can be embedded and connected to the end of the dropper head; the dropper head can be provided with a plurality of inclined return holes.
[0008] According to the present application, a double-clamp single-cylinder bridge plug for preventing setting misalignment solves the common problems of poor setting and low backflow efficiency during operation through structural optimization, and has the following technical advantages:
[0009] (1) The design of the lateral guide ensures the uniformity of the opening of the slip, that is, the stability of the setting seal and has sufficient anchoring force.
[0010] (2) By designing auxiliary return holes, the time for return work is saved, which indirectly saves the economic cost of construction. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the dual-card single-tube bridge plug of this application.
[0012] Figure 2 This is a cross-sectional view of the dual-card single-cylinder bridge plug of this application.
[0013] Figure 3 This is a cross-sectional view of the upper card seal component of this application.
[0014] Figure 4 This is a schematic diagram of the card sealing component of this application.
[0015] Figure 5 This is a cross-sectional view of the lower card sealing component of this application.
[0016] Figure 6 This is a sectional view of the present application. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined. The terms indicating orientation in this application are for the purpose of describing the application in conjunction with the accompanying drawings and do not constitute any limitation on the scope of protection. As shown in the accompanying drawings, "above" refers to the left side of the drawing, and "below" refers to the right side of the drawing. For downhole tools, "above" refers to the side of the downhole tool closer to the wellhead, and "below" refers to the side of the downhole tool farther from the wellhead.
[0018] The purpose of this application is to provide a bridge plug structural design that can improve the setting stability of the bridge plug and the efficiency of downhole flowback operations. According to this application, a double-clamp single-tube bridge plug for preventing setting misalignment includes a central tube 8 and a slip connector 1. The lower end of the central tube 8 is connected to the slip connector 1, and an upper slip connection portion 9 is provided on the side of the central tube 8 away from the slip connector 1. A pull rod is provided inside the central tube 8, and the pull rod is connected to the slip connector 1 through a connecting joint. The slip connector 1 is provided with a slip thread so that when the force applied by the pull rod exceeds a threshold, the slip thread is sheared, causing the slip connector 1 to move relative to the central tube 8.
[0019] Specifically, the central tube 8 and the slip base 9 can be connected by, for example, a threaded connection or by a mounting base. Two sets of locking assemblies are provided between the central tube 8 and the dropper head 1, and a rubber sleeve 4 is provided between the two sets of locking assemblies. The two sets of locking assemblies are mirror images of the rubber sleeve 4. The two sets of locking assemblies include an upper locking assembly and a lower locking assembly. The upper locking assembly is located between the upper slip connecting part 9 and the rubber sleeve 4, and the lower locking assembly is located between the rubber sleeve 4 and the dropper head 1. Preferably, protective bowls 5 can also be provided on both sides of the rubber sleeve 4, i.e., an upper protective bowl and a lower protective bowl can be included. The upper locking assembly includes an upper slip 7 and an upper cone 6, with the thicker end of the upper cone 6 facing downwards; the lower locking assembly includes a lower slip 2 and a lower cone 3, with the thicker end of the lower cone 3 facing upwards. The upper slip 7 and the upper cone 6 can be located between the upper slip connecting part 9 and the upper protective bowl, with the upper slip 7 fitted over the upper cone 6. The lower slip 2 and lower cone 3 can be positioned between the lower protective cup and the release head 1, with the lower slip 2 fitted over the lower cone 3. The upper slip 7 and lower slip 2 each have multiple slip segments, with a separating groove 13 between them. The openings of the separating grooves 13 face the upper cone 6 and lower cone 3 respectively, facilitating slip expansion. Laterally positioned lateral guides 12 are provided within the separating grooves 13, and these lateral guides 12 can be mounted on the upper cone 6 and lower cone 3. The lateral guides 12 can be, for example, guide pins, used to achieve uniform opening of the slips by sliding them in a fixed position, ensuring uniform stress on the set seal and providing a better working foundation for subsequent downhole fracturing operations. Preferably, the slip teeth 10 are staggered on each slip segment to ensure more uniform slip tooth embedding.
[0020] Preferably, the upper slip connecting part 9 has a first threaded hole on its outer circumference, and the central tube 8 has a second threaded hole. During installation, the first threaded hole on the upper slip connecting part 9 is aligned with the second threaded hole on the central tube 8, and a shear pin 11 is inserted to lock them in place. A mating fitting can be provided between the upper slip 7 and the upper slip connecting part 9, for example, an insertion flange and an insertion groove. Similarly, the lower slip and the central tube can also be connected in a similar way, with the lower slip and the dropper 1 using an embedded connection, that is, the end of the lower slip is embedded into the end of the dropper 1, which can be achieved, for example, by a threaded connection.
[0021] According to this application, a double-clamp single-cylinder bridge plug for preventing seat misalignment is assembled as follows: Step 1, with the thick end of the center tube 8 facing downwards, the upper clamp connecting part 9 is fitted onto the center tube 8 and pushed to the upper clamp connecting part, aligning the threaded hole on the outer circumference of the upper clamp connecting part 9 with the threaded hole on the center tube 8, and locking it with a shear pin 11; Step 2, the open end of the upper clamp 7 is fitted onto the center tube 8 with upwards, and the upper clamp 7 and the upper clamp connecting part 9 are connected by a fitting; Step 3, the lateral guide 12 is locked into the threaded hole on the side of the upper cone 6. The assembly is formed, and then the tapered part of the assembly is fitted onto the central tube 8. The shear pin 11 is used to lock the threaded hole corresponding to the upper cone 6 and the central tube 8. Step four: Assemble the protective cup 5 onto the upper cone 6. Step five: Insert the soluble adhesive cartridge 4. Step six: Place the protective cup 5 and the adhesive cartridge 3 together. Step seven: Install the lower cone 3 onto the central tube 8 with its tapered end facing upwards, following the steps in step three. Step eight: Install the lower slip 2 with its coarse end facing downwards onto the central tube, ensuring proper alignment with the lateral guide 12. Step nine: Finally, lock the release end 1 through the thread at the end of the central tube 8. This bridge plug design fully considers the requirements of well operations. After setting, it provides strong anchoring force and stable operation. It also incorporates a design to increase backflow efficiency, providing a foundation for rapid backflow in the later stages and improving construction speed.
[0022] According to this application, a double-clamp single-cylinder bridge plug for preventing setting misalignment operates as follows: During the bridge plug setting process, the fixed surface is the left end face of the upper clamp connecting part 9. A pulling force is applied to the release head 1 via a pull rod. Since the upper clamp connecting part 9, the upper cone 6, and the lower cone 3 are all equipped with locking shear pins 11, as the pulling force increases, the shear pins of the upper clamp connecting part 9 are sheared first. Subsequently, the upper clamp connecting part 9 pushes the upper clamp 7, transmitting force to the upper cone 6, causing the shear pins 11 on the upper cone 6 to also be sheared. Then, the force transmitted from the upper clamp connecting part 9 is applied to the lower cone 3 through the first protective cup, the rubber sleeve 4, and the second protective cup, causing the shear pins 11 on the lower cone 3 to also be sheared. The shear pins of the above three components are intended to prevent the bridge plug from being subjected to external forces in a non-working state, causing premature activation of the bridge plug components and leading to bridge plug failure. As the tension increases, after the upper slip 7 and lower slip 2 reach their stress limits, the slip segments expand and separate along the conical surface. Simultaneously, the rubber sleeve 4 is gradually compressed and expanded under pressure until the outer surfaces of the upper slip 7, lower slip 2, and rubber sleeve 4 contact the inner wall of the sleeve. As the tension increases, the slip teeth 10 on the slips become embedded in the sleeve wall, acting as an anchoring mechanism for the bridge plug.
[0023] Once the thrust reaches a certain level, the setting tie rod shears the release thread on the release end 1, and the setting connection joint and setting tie rod are removed together with the setting tool. Then, a soluble ball of the appropriate size is pumped to plug the central tube 8 of the bridge plug, and fracturing is performed on the upper section. After fracturing is completed, the fluid in the lower section can flow through a single flow channel, thus enabling normal blowout or production. During blowout and production, the soluble bridge plug gradually dissolves in the well fluid and eventually disappears.
[0024] like Figure 2-3 As shown, the lateral guide 12 of this application is located on the cone in a three-dimensional assembly relationship, between the partition grooves of each slip segment. The principle by which the lateral guide 12 prevents setting misalignment lies in its guiding function, that is, it allows each slip segment to move along the preset bridge plug axis direction. When the slip segments are subjected to uneven force and deflect, failing to expand, the lateral guide 12 can forcibly prevent the misalignment from occurring. Figure 2 For example, the slip segments of the upper slip 7 expand separately by being pushed to the right by the upper slip connecting part 9. During the movement, the connection points of each slip segment will gradually crack due to limited strength, adding load inward or outward, causing the slip segments to deflect inward or outward. At this time, since the lateral guide 12 is located on the side of the slip segment, its circumferential position will not change due to the axial movement of the slip. When the slip segment moves to a certain position, it will touch the lateral guide 12, stopping its deflection and causing it to move only in the axial direction, thereby ensuring the stability of the slip segment's movement direction and ensuring uniform expansion of the slip.
[0025] Figure 6 This is a cross-sectional view of the dropper head 1 of this application. The dropper head 1 has multiple return holes 14 arranged at an angle. The bridge plug of this application improves the return efficiency by adding auxiliary return holes on the side wall of the dropper head. For example, for a commonly used base with an outer diameter of 110mm, 10 φ10 circular through holes can be distributed in the circumferential direction of the side wall of the dropper head, with the axis of the circular holes making an angle of 45-55° with the axis of the bridge plug, preferably 50°, to achieve the best return effect.
[0026] This application differs significantly in structure from traditional bridge plugs, primarily in the placement of the slipper and the lower and upper slippers. The differences are:
[0027] (1) The bridge plug of this application adds a lateral guide between each slip to ensure that the unexpanded slips expand smoothly and evenly during the movement of the slips, thus ensuring the stability and safety of the setting seal.
[0028] (2) In addition to the above functions and effects, the optimized structure of the bridge plug in this application also includes a backflow hole structure design to improve the backflow efficiency, which greatly improves the backflow efficiency and solves the problem of high construction cost caused by the low backflow efficiency of common bridge plugs.
[0029] Although the embodiments disclosed in this application are as described above, the content is merely for the purpose of facilitating understanding of this application and is not intended to limit this application. Any person skilled in the art to which this application pertains may make any modifications and changes in the form and details of the implementation without departing from the spirit and scope disclosed in this application; however, the scope of patent protection of this application shall still be determined by the scope defined in the appended claims.
Claims
1. A dual packer single barrel bridge plug for preventing setting off center, characterized in that, The center tube is connected with the releasing head, and two sets of clamping and sealing assemblies are arranged between the center tube and the releasing head, the two sets of clamping and sealing assemblies comprise an upper clamping and sealing assembly and a lower clamping and sealing assembly, the upper clamping and sealing assembly comprises an upper slip and an upper cone, and the upper slip is sleeved outside the upper cone; the lower clamping and sealing assembly comprises a lower slip and a lower cone, and the lower slip is sleeved outside the lower cone; the upper slip and the lower slip are respectively provided with a plurality of slip petals, and a separation groove is arranged between the plurality of slip petals, and a lateral guide is arranged in the separation groove.
2. The dual string bridge plug of claim 1, wherein, An upper slip connecting portion is arranged on the center tube away from the releasing head.
3. The dual string bridge plug of claim 2, wherein, The center tube and the upper slip connecting portion are fixedly connected through threads or are connected through a mounting base.
4. The double-string, single-arch bridge plug of any of claims 1-3, wherein, A rubber sleeve is arranged between the two sets of clamping and sealing assemblies, the upper clamping and sealing assembly is arranged between the upper slip connecting portion and the rubber sleeve, and the lower clamping and sealing assembly is arranged between the rubber sleeve and the releasing head.
5. The dual string bridge plug of claim 4, wherein, Upper and lower protecting bowls are further arranged on both sides of the rubber sleeve, the upper slip and the upper cone are arranged between the upper slip connecting portion and the upper protecting bowl, and the lower slip and the lower cone are arranged between the lower protecting bowl and the releasing head.
6. The dual string bridge plug of claim 5, wherein, The upper clamping and sealing assembly and the lower clamping and sealing assembly are arranged in a mirror image relative to the rubber sleeve.
7. The double-string, single-arch bridge plug of any of claims 1-3, 5, wherein, The lateral guides are respectively arranged on the upper cone and the lower cone.
8. The double-string, single-arch bridge plug of any of claims 1-3, 5, wherein, A first threaded hole is arranged on the upper slip connecting portion, a second threaded hole is arranged on the center tube, the first threaded hole is aligned with the second threaded hole, and a shear pin is inserted into the first threaded hole and the second threaded hole to lock them.
9. The double-string, single-arch bridge plug of any of claims 1-3, 5, wherein, An end portion of the lower slip is embedded and connected to an end portion of the releasing head.
10. The double-string, single-arch bridge plug of any of claims 1-3, 5, wherein, A plurality of flowback holes are arranged on the releasing head in an inclined manner.