Drillable bridge plug

Abstract

The utility model discloses a drillable bridge plug which comprises a pull rod, a baffle ring sleeved on the outer side of the pull rod, a push pipe, a slip, a taper pipe arranged between the push pipe and the slip and used for expanding the push pipe and the slip, and a guide head fixed below the pull rod, a plurality of ring grooves are arranged on the push pipe, and a sealing ring is arranged in each ring groove. Protective sleeves with U-shaped sections are arranged outside the sealing rings; a clamping groove for accommodating the protective sleeve is formed in the outer side of the push tube; the protective sleeve is of a multi-section structure, and the two ends of the protective sleeve are embedded into the clamping grooves in a close fit mode. The protective sleeves do not protrude out of the surface of the push pipe after being installed, and the multiple segments of protective sleeves are enclosed into a ring shape in the clamping grooves. A flexible layer is arranged in the middle of the protective sleeve. The utility model provides a drillable bridge plug. According to the drillable bridge plug, a protective sleeve and a flexible layer are arranged, so that a sealing ring is protected, and meanwhile it is guaranteed that no obstacle exists between the sealing ring and the inner wall of a sleeve during plugging, and whole-circle tight contact can be achieved for sealing.

Description

Technical Field

[0001] The utility model relates to the technical field of downhole tools in oil fields. More specifically, the utility model relates to a drillable bridge plug. Background Art

[0002] At present, during the operation of oil and gas wells, drillable bridge plugs have been widely used for formation isolation; using bridge plugs for formation isolation can effectively achieve staged fracturing. After the staged fracturing construction is completed, the drillable bridge plugs need to be drilled out in sequence.

[0003] The utility model patent with the patent application number CN217538648U discloses a composite material drillable bridge plug. The lower part of the pull rod is threadedly connected to the tail pipe. The outer side of the tail pipe is a conical head with a smaller upper part and a larger lower part. A push pipe is sleeved outside the conical head. The push pipe extends upward to the step part of the pull rod. Three annular grooves are opened on the push pipe, and a sealing ring is installed in each annular groove. The utility model protects the sealing ring through a cast iron ring to prevent the sealing ring from being damaged during the downhole process and reducing the sealing effect. However, it is difficult to control the falling position of the cast iron ring after it is broken. If the cast iron ring is still between the sealing ring and the inner wall of the casing after being broken, it will affect the sealing effect. Summary of the Utility Model

[0004] An object of the utility model is to solve the above problems and / or defects and provide the advantages described below.

[0005] To achieve these objects and other advantages of the utility model, there is provided a drillable bridge plug including: a pull rod, a retaining ring, a push pipe and slips sleeved outside the pull rod, a tapered pipe disposed between the push pipe and the slips for expanding the two, a guide head fixed below the pull rod. A plurality of annular grooves are opened on the push pipe, and sealing rings are provided in the annular grooves. A protective sleeve with a U-shaped cross-section is provided outside each sealing ring;

[0006] A card slot for accommodating the protective sleeve is provided on the outer side of the push pipe;

[0007] The protective sleeve has a multi-segment structure, and its two ends are tightly and fittingly embedded in the card slot;

[0008] After being installed, the protective sleeve does not protrude from the surface of the push pipe, and the multi-segment protective sleeves enclose into a ring in the card slot;

[0009] The middle of the protective sleeve is configured as a flexible layer.

[0010] Preferably, an easily breakable groove is provided in the central vertical axis direction of the flexible layer.

[0011] Preferably, a positioning hole Ⅰ is provided on the tapered surface of the tapered pipe;

[0012] A positioning pin Ⅰ is provided in the positioning hole Ⅰ;

[0013] An elastic member I is provided between the positioning pin I and the positioning hole I;

[0014] The slip is provided with a positioning hole II which cooperates with the positioning pin I after the slip is expanded to a certain position.

[0015] Preferably, a positioning hole III is provided on the upper surface of the guide head;

[0016] A positioning pin II is provided in the positioning hole III;

[0017] An elastic member II is provided between the positioning pin II and the positioning hole III;

[0018] The slip is provided with a positioning hole IV which cooperates with the positioning pin II after the slip is expanded to a certain position.

[0019] The utility model at least includes the following beneficial effects: by arranging a protective sleeve on the outside of the sealing ring, the sealing ring is prevented from being damaged and reducing the sealing effect during the process of going down the well; by arranging a flexible layer in the middle of the protective sleeve and fixing its two ends in the push tube, the push tube is expanded and deformed during the process of the push tube expansion, and the flexible layer is broken, and moves from the broken part to the embedded parts at the two ends, so that the sealing ring is exposed, so that there is no obstacle between the sealing ring and the inner wall of the casing, and the whole circle can be in close contact for sealing; at the same time, the flexible layer of the protective sleeve is broken into upper and lower ends, which are respectively attached to the upper and lower sides of the sealing ring, and the sealing ring can be squeezed and blocked on the upper and lower sides of the sealing ring to enhance the sealing effect.

[0020] Other advantages, objectives and features of the present invention will be reflected in part through the following description, and in part will be understood by those skilled in the art through research and practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A cross-sectional view of a drillable bridge plug in one embodiment of the utility model;

[0022] Figure 2 A cross-sectional view of a protective sleeve of a drillable bridge plug in one embodiment of the utility model;

[0023] Figure 3 A fractured cross-sectional view of a protective sleeve of a drillable bridge plug in one embodiment of the utility model;

[0024] Figure 4 A cross-sectional view of a slip of a drillable bridge plug in one embodiment of the utility model;

[0025] Figure 5 The present invention is a schematic structural diagram of a drillable bridge plug in one embodiment of the present invention.

[0026] Markings in the figure: 1. Pull rod, 2. Retaining ring, 3. Push tube, 31. Ring groove, 4. Conical tube, 41. Positioning hole I, 42. Positioning pin I, 5. Slip, 51. Positioning hole II, 52. Positioning hole IV, 6. Guide head, 61. Positioning hole III, 62. Positioning pin II, 7. Sealing ring, 8. Protective sleeve, 81. Breaking groove. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0028] It should be understood that terms such as “having”, “including” and “comprising” used herein do not recite the existence or addition of one or more other elements or combinations thereof.

[0029] It should be noted that in the description of the present invention, the orientation or position relationship indicated by the term is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present utility model, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the utility model can be understood according to specific circumstances.

[0031] In addition, in the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0032] Example 1

[0033] A drillable bridge plug having a structure as follows Figure 1-5As shown in the figure, it includes: a pull rod 1, a retaining ring 2, a push tube 3, and a slip 5 sleeved outside the pull rod 1, a tapered tube 4 arranged between the push tube 3 and the slip 5 to expand the two, and a guide head 6 fixed below the pull rod 1. A plurality of annular grooves 31 are formed on the push tube 3, and sealing rings 7 are arranged in each annular groove 31. A protective sleeve 8 with a U-shaped cross-section is arranged outside each sealing ring 7.

[0034] A clamping groove for accommodating the protective sleeve 8 is arranged on the outside of the push tube 3.

[0035] The protective sleeve 8 has a multi-segment structure, and its two ends are tightly fitted and embedded in the clamping groove.

[0036] After the protective sleeve 8 is installed, it does not protrude from the surface of the push tube 3, and the multi-segment protective sleeves 8 are enclosed in a ring shape in the clamping groove.

[0037] The middle of the protective sleeve 8 is configured as a flexible layer.

[0038] In actual application, three annular grooves 31 are formed on the push tube 3, and three sealing rings 7 and three protective sleeves 8 are provided in a matching manner. The middle of the protective sleeve 8 is configured as a flexible layer, and the two ends are made of hard materials and embedded in the clamping groove to cover the sealing ring 7 to prevent the sealing ring 7 from protruding and being worn during the falling process. After installation, the multi-segment protective sleeves 8 can be connected into one body by welding, bonding, etc. to improve stability, so that the protective sleeve 8 can expand and deform and the flexible layer can break smoothly.

[0039] Working principle: During use, the pull rod 1 is connected to the setting tool, and the retaining ring 2 is abutted against the setting tool. After the drillable bridge plug is placed in the casing and reaches the designed setting depth, the setting tool is triggered to drive the pull rod 1 and the retaining ring 2 to squeeze the parts sleeved on the pull rod 1, forcing the tapered tube 4 to expand the push tube 3. The protective sleeve 8 expands and deforms, and the flexible layer breaks, and moves from the fracture to the clamping positions at both ends, so that the sealing ring 7 is exposed. Thus, there is no obstruction between the sealing ring 7 and the inner wall of the casing after expansion, and the sealing ring 7 can be in close contact with the inner wall of the casing in a whole circle for sealing. At the same time, the flexible layer of the protective sleeve 8 breaks into upper and lower ends, which are respectively attached to the upper and lower sides of the sealing ring 7, and can squeeze and seal the sealing ring 7 on the upper and lower sides of the sealing ring 7 to enhance the sealing effect. At the same time, the guide head 6 pushes the slip 5 to move towards the lower conical surface of the tapered tube 4 for expansion and closely adheres to the inner wall of the casing for anchoring.

[0040] By arranging a protective sleeve 8 on the outside of the sealing ring 7, the sealing ring 7 is prevented from being damaged and reducing the sealing effect during the process of going down the well; by arranging a flexible layer in the middle of the protective sleeve 8 and fixing its two ends in the push tube 3, the push tube 3 is expanded and deformed during the expansion of the push tube 3, and the flexible layer is broken, and moves from the broken part to the embedded parts at both ends, so that the sealing ring 7 is exposed, so that there is no obstacle between the sealing ring 7 and the inner wall of the casing, and the whole circle can be in close contact for sealing. At the same time, the flexible layer of the protective sleeve 8 is broken into upper and lower ends, which are respectively attached to the upper and lower sides of the sealing ring 7, and the sealing ring 7 can be squeezed and blocked on the upper and lower sides of the sealing ring 7 to enhance the sealing effect.

[0041] Example 2

[0042] This embodiment 2 is a preferred embodiment of the present utility model, which discloses the following improvements based on the embodiment 1: a breakable groove 81 is provided in the center of the flexible layer in the direction perpendicular to the axis.

[0043] Working principle: The provision of the easy-to-break groove 81 allows the protective sleeve 8 to break along the easy-to-break groove 81 when it is deformed, which is beneficial to ensure its breaking effect and further ensure the sealing effect of the sealing ring formed after the breaking.

[0044] Example 3

[0045] This embodiment 3 is a preferred embodiment of the present utility model, and the specific structure is as follows Figure 5 As shown, it discloses the following improvements based on the embodiment 1: a positioning hole I41 is provided on the conical surface of the conical tube 4;

[0046] A positioning pin Ⅰ42 is provided in the positioning hole Ⅰ41;

[0047] An elastic member I is provided between the positioning pin I 42 and the positioning hole I 41;

[0048] The slip 5 is provided with a positioning hole II 51 which cooperates with the positioning pin I 42 after the slip 5 is expanded to the right position.

[0049] The upper surface of the guide head 6 is provided with a positioning hole III 61;

[0050] A positioning pin II 62 is provided in the positioning hole III 61;

[0051] An elastic member II is provided between the positioning pin II 62 and the positioning hole III 61;

[0052] The slip 5 is provided with a positioning hole IV52 which cooperates with the positioning pin II 62 after the slip 5 is expanded to the right position.

[0053] Working principle: The positioning pins I42 and II62 are arranged to prevent the position of the slip 5 from changing after it is expanded to its full position, thereby preventing the slip 5 from slipping into the casing and causing anchor failure; at the same time, when the device is drilled and removed, the connected parts are not easy to rotate relative to each other, which is conducive to drilling and removal.

[0054] The above solutions are only an illustration of a preferred example, but are not limited thereto. When implementing the present utility model, appropriate replacement and / or modification can be performed according to user needs.

[0055] The number of devices and processing scales described here are used to simplify the description of the utility model. Applications, modifications and variations of the utility model are obvious to those skilled in the art.

[0056] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and the embodiments. It can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily realized. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described here.

Claims

1. A drillable bridge plug, comprising: A pull rod, a retaining ring, a push tube and a slip that are sleeved outside the pull rod, a tapered tube disposed between the push tube and the slip for expanding the two, a guiding head fixed below the pull rod, and a plurality of annular grooves are formed in the push tube, and sealing rings are arranged in each annular groove. It is characterized in that protective sleeves with a U-shaped cross section are arranged outside each sealing ring; A clamping groove for accommodating the protective sleeve is arranged outside the push tube; The protective sleeve has a multi-segment structure, and its two ends are tightly and fittingly embedded in the clamping groove; After the protective sleeve is installed, it does not protrude from the surface of the push tube, and the multi-segment protective sleeves are enclosed in a ring shape in the clamping groove; The middle of the protective sleeve is configured as a flexible layer.

2. The drillable bridge plug according to claim 1, characterized in that: A breakable groove is arranged in the central vertical axis direction of the flexible layer.

3. The drillable bridge plug according to claim 1, characterized in that: A positioning hole Ⅰ is arranged on the tapered surface of the tapered tube; A positioning pin Ⅰ is arranged in the positioning hole Ⅰ; An elastic member Ⅰ is arranged between the positioning pin Ⅰ and the positioning hole Ⅰ; A positioning hole Ⅱ that cooperates with the positioning pin Ⅰ after the slip is expanded in place is arranged on the slip; 4. The drillable bridge plug according to claim 1, wherein: A positioning hole Ⅲ is arranged on the upper surface of the guiding head; A positioning pin Ⅱ is arranged in the positioning hole Ⅲ; An elastic member Ⅱ is arranged between the positioning pin Ⅱ and the positioning hole Ⅲ; A positioning hole Ⅳ that cooperates with the positioning pin Ⅱ after the slip is expanded in place is arranged on the slip;

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