Acid-resistant soluble bridge plug

Abstract

The utility model relates to an acid-resistant soluble bridge plug which comprises a central pipe, an upper slip assembly, an upper cone, a soluble rubber cylinder, a lower cone, a lower slip assembly and a lower connector. The outer surface of each component is coated with an acid-resistant layer; a groove is formed in the middle of the center pipe, the end of the center pipe is connected with the lower connector, the soluble rubber cylinder is arranged in the middle of the groove in a sleeved mode, the upper slip assembly and the upper cone are matched with each other and then installed on one side of the upper portion of the groove, and the lower cone and the lower slip assembly are matched with each other and then installed on one side of the lower portion of the groove. According to the soluble bridge plug sealing device, the inclination of the upper slip assembly and the lower slip assembly is small, the risk of falling after setting sealing is reduced, the outer surface of each component is coated with an acid-resistant layer, the acid-resistant layers are used for preventing a metal structure from being corroded and damaged in an acid environment, and the service life of the soluble bridge plug sealing device in an oil and gas well sealing layer under the acid condition is prolonged.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas well sealing construction, in particular to an acid-resistant soluble bridge plug. Background Art

[0002] Soluble bridge plugs are mainly used in acid fracturing sealing of oil and gas wells. This device has the characteristics of fewer construction steps, short cycle and accurate sealing position, and is widely used in oilfield development, natural gas extraction and other fields.

[0003] During operation, the soluble bridge plug is transported to the predetermined position of the wellbore by using cables or pipe strings, and then the pressure generated by the gunpowder blasting, hydraulic setting or mechanical setting tool acts on the upper slip, and the pulling force acts on the tension component, and the upper and lower cones exert two forces of upper pressure and lower pull on the sealing rubber tube. When the pulling force reaches a certain value, the tension component breaks, and the setting tool and the bridge plug are separated. At this time, the locking device on the center tube of the soluble bridge plug takes effect, the upper and lower slips are broken and embedded in the inner wall of the casing, the rubber tube expands and seals, and the setting is completed.

[0004] In the prior art, for example, in an all-metal soluble bridge plug disclosed in Chinese patent application number CN201922060743.9, when the metal sealing tube and the slip are used to seal the ball seat, the impact force will cause the metal sealing tube and the slip to break rapidly and be embedded in the outer surface of the ball seat under the action of gunpowder explosion. However, due to the large inclination of the surface of the ball seat, there is still a risk of falling off after sealing, and the presence of acidic conditions in the sealing layer of the oil and gas well can easily cause damage to the soluble bridge plug sealing device. Utility Model Content

[0005] The utility model aims to provide an acid-resistant soluble bridge plug to solve the problems encountered in the above-mentioned background technology.

[0006] To achieve the above purpose, the technical solution of the utility model is as follows:

[0007] An acid-resistant soluble bridge plug includes a central tube, an upper slip assembly, an upper cone, a soluble gel tube, a lower cone, a lower slip assembly, and a lower joint; and the outer surface of each component is coated with an acid-resistant layer; a groove is provided in the middle of the central tube, the end of the central tube is connected to the lower joint, the soluble gel tube is sleeved in the middle of the groove, the upper slip assembly cooperates with the upper cone and is installed on the upper side of the groove, and the lower cone cooperates with the lower slip assembly and is installed on the lower side of the groove. Wherein, an axial hole is opened in the central tube, and a guide step for installing a rotating shaft is provided.

[0008] The above scheme also includes a bearing seat, which is a circular ring structure with a rectangular cross-section. The bearing seat is installed at the upper end of the groove.

[0009] In the above scheme, the inner side of the upper slip assembly is provided with a first bevel, the outer wall of the upper cone is inclined and matched with the first bevel; the inner side of the lower slip assembly is provided with a third bevel, the outer wall of the lower cone is inclined and matched with the third bevel. The inclination angle of the outer wall of the lower cone is smaller than the inclination angle of the outer wall of the upper cone, and the inclination angle of the outer wall of the lower cone is 5-15 degrees.

[0010] Furthermore, the upper cava component is provided with a groove in the middle; its outer surface is provided with at least one first circular hole, and the first circular hole is inclined; the lower cava component is provided with a threaded area inside; its outer surface is provided with at least one second circular hole, and the second circular hole is inclined.

[0011] As a preferred solution, the grooves include outer grooves and inner grooves, the outer grooves are provided in plurality and are evenly arranged on the outer peripheral surface of the upper slip assembly, and the inner grooves are provided in plurality and are evenly arranged on the inner diameter surface of the upper slip assembly. In implementation, the upper slip assembly includes a first outer shell and is an integrated structure; the lower slip assembly includes a second outer shell, and the second outer shell is an integrated structure or a split combined structure.

[0012] In the above scheme, the two sides of the soluble gel tube are provided with second bevels, and the interior of the soluble gel tube is provided with a buffer groove. It also includes an outer protective ring and an inner protective ring, both of which are hollow basin-shaped structures, and the outer cone surfaces thereof are provided with cracks; the outer protective ring and the inner protective ring fit together, and after being combined, they are respectively sleeved between the upper cone and the soluble gel tube, and between the soluble gel tube and the lower cone.

[0013] Compared with the prior art, the utility model has the following beneficial effects: in this product, the inclination of the upper and lower groups of slip assemblies is small, which reduces the risk of back-slipping after setting and sealing, and outer and inner protective rings are arranged on the upper and lower sides of the soluble gel tube to protect the soluble gel tube, disperse the buffer force, and use the cracks to increase the adaptability after expansion. In addition, the outer surface of each component is coated with an acid-resistant layer to prevent the metal structure from being corroded and damaged in an acidic environment, and to increase the service life of the soluble bridge plug sealing device under acidic conditions in the sealing layer of oil and gas wells. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The disclosure of the present invention is described with reference to the accompanying drawings. It should be understood that the drawings are only for illustrative purposes and are not intended to limit the scope of protection of the present invention. In the accompanying drawings, the same reference numerals are used to refer to the same components. Among them:

[0015] Figure 1 It is a schematic diagram of the overall connection structure of the utility model;

[0016] Figure 2 It is a structural schematic diagram of the upper slip assembly in the utility model;

[0017] Figure 3 It is a side view structural schematic diagram of the upper slip assembly in the utility model;

[0018] Figure 4 It is a structural schematic diagram of the soluble glue cartridge in the utility model;

[0019] Figure 5 This is a schematic diagram of the structure of the inner guard ring in the utility model;

[0020] Figure 6 It is a side view structural schematic diagram of the inner guard ring in the utility model;

[0021] Figure 7 It is a schematic diagram of the structure of the outer and inner guard rings of the utility model;

[0022] Figure 8 It is a side view structural diagram of the outer and inner guard rings of the utility model;

[0023] Fig. 9 It is a structural schematic diagram of the middle and lower slip assembly of the utility model;

[0024] Fig.10 It is a structural schematic diagram of the lower joint in the utility model.

[0025] Numbers in the figure: 1-center tube; 2-load bearing seat; 3-upper slip assembly; 31-slot; 32-connecting part; 33-first bevel; 34-first circular hole; 35-outer slot; 36-inner slot; 4-upper cone; 5-outer protective ring; 51-first inner diameter; 52-first crack; 53-inner cone; 6-inner protective ring; 61-second inner diameter; 62-second crack; 63-outer cone; 7-soluble rubber tube; 71-second bevel; 72-buffer groove; 8-lower cone; 9-lower slip assembly; 91-third bevel; 92-threaded area; 93-second circular hole; 94-tightening groove; 95-third crack; 10-lower joint; 101-threaded inner diameter; 102-card platform; 103-fourth bevel. DETAILED DESCRIPTION

[0026] In order to make the technical means, creative features, objectives and effects of the utility model easier to understand, the utility model is now further described in detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the utility model in a schematic manner, and therefore only show the relevant components of the utility model.

[0027] According to the technical solution of the utility model, without changing the essential spirit of the utility model, a person skilled in the art can propose a variety of interchangeable structural modes and implementation modes. Therefore, the following specific implementation modes and drawings are only exemplary descriptions of the technical solution of the utility model, and should not be regarded as the entirety of the utility model or as a limitation or restriction to the technical solution of the utility model.

[0028] The technical solution of the utility model is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0029] Embodiment 1, as Figure 1 As shown, an acid-resistant soluble bridge plug includes a central pipe 1, an upper slip assembly 3, an upper cone 4, a soluble gel tube 7, a lower cone 8, a lower slip assembly 9, and a lower joint 10. The outer surfaces of the listed components are coated with an acid-resistant layer, which can be an organic coating, an inorganic coating, a polyester coating, or an epoxy resin coating, and is used to prevent the metal structure from being corroded and damaged in an acidic environment.

[0030] A groove is provided in the middle of the central pipe 1, the end of the central pipe 1 is threadedly connected to the lower joint 10, other components, such as the soluble gel tube 7, are set in the middle of the groove, the upper slip assembly 3 and the upper cone 4 are installed on the upper side of the groove after being matched with each other, and the lower cone 8 and the lower slip assembly 9 are installed on the lower side of the groove after being matched with each other. By setting the front and rear slip assemblies, the bridge plug can be well set during operation.

[0031] The central tube 1 is provided with an axial hole and a guide step for installing the rotating shaft to facilitate the transportation of the product to the working area. Fig.10 A threaded inner diameter 101 is provided at the inner axis of the lower joint 10, a clamping table 102 in contact with the rotating shaft is provided on the side close to the inlet, and a fourth oblique opening 103 is provided on the outer axis to facilitate extension into the working position of the seal.

[0032] Embodiment 2, an acid-resistant soluble bridge plug, includes a central tube 1, an upper slip assembly 3, an upper cone 4, a soluble rubber tube 7, a lower cone 8, a lower slip assembly 9, a lower joint 10, and a bearing seat 2. The bearing seat 2 is a circular ring structure with a rectangular cross section. The bearing seat 2 is installed at the upper port of the groove to provide support for the upper slip assembly 3.

[0033] See also Figure 2 The inner side of the upper slip assembly 3 is provided with a first oblique opening 33, and the outer wall of the upper cone 4 is inclined and matched with the first oblique opening 33; please refer to Fig. 9 A third oblique opening 91 is provided on the inner side of the lower slip assembly 9 , and the outer wall of the lower cone 8 is inclined and matched with the third oblique opening 91 .

[0034] As a preferred solution, the outer wall inclination angle of the lower cone 8 is smaller than the outer wall inclination angle of the upper cone 4, and the outer wall inclination angle of the lower cone 8 is 5-15 degrees. The smaller inclination angle makes it easier to seal after blasting, and the lower slip assembly 9 and the lower cone 8 are squeezed against each other to seal first, and the upper slip assembly 3 and the upper cone 4 are further sealed, and the two form a double sealing effect.

[0035] See also Figure 2 and Figure 3 The upper slip assembly 3 is provided with a slot 31, which includes an outer slot 35 and an inner slot 36. A plurality of outer slots 35 are provided and are evenly arranged on the outer peripheral surface of the upper slip assembly 3, and a plurality of inner slots 36 are provided and are evenly arranged on the inner diameter surface of the upper slip assembly 3. The slot 31 is provided to increase the telescopic performance of the product and make it better wrap around the seal.

[0036] In addition, the outer surface of the upper slip assembly 3 is provided with at least one first circular hole 34, which is inclined and has slip teeth installed inside. The lower slip assembly 9 is provided with a threaded area 92 inside, which is used to be threadedly connected with the center pipe and to limit the position. Fig. 9 At least one second circular hole 93 is provided on its outer surface. The second circular hole 93 is inclined and a slip tooth is also installed inside.

[0037] In implementation, the upper slip assembly 3 includes a first housing and is an integrated structure. The lower slip assembly 9 includes a second housing, which is an integrated structure or a split combined structure. When the lower slip assembly 9 adopts an integrated structure, its appearance is similar to Figure 3 As shown, there is only a third crack groove 95 similar to the outer groove 35, and the third crack grooves 95 are evenly distributed on the third bevel 91. When the lower slip assembly 9 adopts a split structure, tightening grooves 94 are provided on the upper and lower sides of its outer circumference, and the split lower slip assembly 9 is fixed together by installing a sealing ring. In addition, the third crack grooves 95 can be arranged on the second shell in a staggered manner, that is, the third crack grooves 95 are staggered on the left and right sides of the second shell, which is also one of the integrated structures.

[0038] See also Figure 4 The two sides of the soluble gel tube 7 are provided with second oblique openings 71, and the interior of the soluble gel tube 7 is provided with a buffer groove 72. The soluble gel tube 7 is installed between the upper and lower groups of slip assemblies, specifically at the lower end of the upper cone 4 and the upper end of the lower cone 8, and has a certain elastic buffer force, so that it can better compress the oil and gas well sealing part after sealing.

[0039] Embodiment 3, an acid-resistant soluble bridge plug, including a central tube 1, an upper slip assembly 3, an upper cone 4, a soluble gel tube 7, a lower cone 8, a lower slip assembly 9, a lower joint 10, and an outer protective ring 5 and an inner protective ring 6, which are mainly used to protect the soluble gel tube 7. The outer protective ring 5 and the inner protective ring 6 are both hollow basin-shaped structures, and cracks are opened on the outer cone surface to increase the adaptability after expansion. The outer protective ring 5 and the inner protective ring 6 are fitted together, and after being combined, they are respectively set between the upper cone 4 and the soluble gel tube 7, and between the soluble gel tube 7 and the lower cone 8.

[0040] For details, please refer to Figures 5 to 8 The outer retaining ring 5 has a first inner diameter 51 in the middle, a first crack 52 is provided on the outer edge, and an inner conical surface 53 is provided on the inner side. The inner conical surface 53 is used to fit with the outer arm of the inner retaining ring 6. The inner retaining ring 6 has a second inner diameter 61 in the middle, a second crack 62 is provided on the outer edge, and an outer conical surface 63 is provided on the outer side. The outer conical surface 63 is used to fit with the inner conical surface 53. When squeezed by impact force, the first crack 52 and the second crack 62 can play a buffering role and open the notch.

[0041] In summary, in this product, the inclination of the upper and lower sets of slip assemblies is small, which reduces the risk of back-off after setting and sealing, and outer protective rings 5 ​​and inner protective rings 6 are also set on the upper and lower sides of the soluble gel tube 7 to protect the soluble gel tube 7, disperse the buffer force, and use the cracks to increase the adaptability after expansion. In addition, the outer surface of each component is coated with an acid-resistant layer to prevent the metal structure from being corroded and damaged in an acidic environment, and to increase the service life of the soluble bridge plug sealing device under acidic conditions in the sealing layer of oil and gas wells.

[0042] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. These undisclosed elements are all prior art that can be known to those skilled in the art.

[0043] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only the specific implementation method of the utility model and is not used to limit the protection scope of the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. An acid-resistant soluble bridge plug, characterized in that: The invention comprises a central tube (1), an upper slip assembly (3), an upper cone (4), a soluble gel cartridge (7), a lower cone (8), a lower slip assembly (9), and a lower joint (10); and the outer surfaces of each component are coated with an acid-resistant layer; a groove is provided in the middle of the central tube (1); the end of the central tube (1) is connected to the lower joint (10); the soluble gel cartridge (7) is sleeved in the middle of the groove; the upper slip assembly (3) and the upper cone (4) are installed on the upper side of the groove after being matched with each other; and the lower cone (8) and the lower slip assembly (9) are installed on the lower side of the groove after being matched with each other.

2. The acid-resistant soluble bridge plug according to claim 1, characterized in that: An axial hole is provided in the central tube (1), and a guide step for installing the rotating shaft is provided.

3. The acid-resistant soluble bridge plug according to claim 1, characterized in that: It also comprises a bearing seat (2), which is a circular ring structure with a rectangular cross section. The bearing seat (2) is installed at the upper end of the groove.

4. The acid-resistant soluble bridge plug according to claim 1, characterized in that: The inner side of the upper slip assembly (3) is provided with a first oblique opening (33), and the outer wall of the upper cone (4) is inclined and matched with the first oblique opening (33); the inner side of the lower slip assembly (9) is provided with a third oblique opening (91), and the outer wall of the lower cone (8) is inclined and matched with the third oblique opening (91).

5. The acid-resistant soluble bridge plug according to claim 4, characterized in that: The inclination angle of the outer wall of the lower cone (8) is smaller than the inclination angle of the outer wall of the upper cone (4), and the inclination angle of the outer wall of the lower cone (8) is 5-15 degrees.

6. The acid-resistant soluble bridge plug according to claim 4, characterized in that: The upper slip assembly (3) is provided with a groove (31) in the middle; its outer surface is provided with at least one first circular hole (34), and the first circular hole (34) is arranged obliquely; the lower slip assembly (9) is provided with a threaded area (92) inside; its outer surface is provided with at least one second circular hole (93), and the second circular hole (93) is arranged obliquely.

7. The acid-resistant soluble bridge plug according to claim 6, characterized in that: The grooves (31) include outer grooves (35) and inner grooves (36); a plurality of outer grooves (35) are provided and are evenly distributed on the outer peripheral surface of the upper slip assembly (3); and a plurality of inner grooves (36) are provided and are evenly distributed on the inner diameter surface of the upper slip assembly (3).

8. The acid-resistant soluble bridge plug according to claim 6, characterized in that: The upper slip assembly (3) comprises a first outer shell and is an integrated structure; the lower slip assembly (9) comprises a second outer shell and is an integrated structure or a split combined structure.

9. The acid-resistant soluble bridge plug according to claim 1, characterized in that: Second oblique openings (71) are provided on both sides of the soluble colloid tube (7), and a buffer groove (72) is provided inside the soluble colloid tube (7).

10. The acid-resistant soluble bridge plug according to claim 1, characterized in that: The invention also comprises an outer protective ring (5) and an inner protective ring (6), wherein the outer protective ring (5) and the inner protective ring (6) are both hollow basin-shaped structures, and grooves are provided on the outer cone surfaces thereof; the outer protective ring (5) and the inner protective ring (6) are fitted together, and after being assembled, they are respectively inserted between the upper cone (4) and the soluble gel tube (7), and between the soluble gel tube (7) and the lower cone (8).

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