All-metal soluble bridge plug with herringbone plugging structure and setting method

Abstract

The invention discloses an all-metal soluble bridge plug with a herringbone plugging structure and a setting method, and relates to the technical field of bridge plugs. The all-metal soluble bridge plug comprises a mandrel and a tubular shaft arranged outside the mandrel in a sleeving mode, the outer surface of the tubular shaft is sleeved with an upper slip assembly and a lower slip assembly, and a lower slip pressing table is arranged above the lower slip assembly; an upper slip pressing table is arranged below the upper slip assembly, a herringbone plugging assembly is arranged between the upper slip pressing table and the lower slip pressing table, and the middle position of the pipe shaft is sleeved with the herringbone plugging assembly. According to the all-metal soluble bridge plug with the herringbone plugging structure and the setting method, stable plugging can be achieved, and the problem of setting failure caused by component slippage and untight setting is solved.

Description

Technical Field

[0001] The invention relates to the technical field of bridge plugs, and in particular to a full-metal soluble bridge plug with a herringbone plugging structure and a setting method. Background Art

[0002] During the shale oil and gas production process, the oil well will pass through multiple oil and gas layer areas because the oil and gas are distributed in different underground areas. The completion process of the oil and gas well requires perforating and fracturing the oil and gas layer areas one by one starting from the bottom oil and gas layer. Before each level of perforation and fracturing, it is necessary to plug the oil and gas layer that has been perforated and fractured in the previous level to ensure that the liquid flow and pressure required for fracturing of each layer are not diverted and divided by the already fractured oil and gas layer.

[0003] The bridge plug provided by the prior art includes: a center tube, a rubber cylinder and two slips, the rubber cylinder and the two slips are sleeved on the center tube and the rubber cylinder is located between the two slips. When in use, the slips are anchored to the casing, and the rubber cylinder is squeezed to expand the rubber cylinder to seal and fix the bridge plug in the casing. The soluble sealing ball adapted to the center tube is put in to seal the pipe opening to complete the isolation. After the isolation operation is completed, the soluble ball dissolves, and the casing can be connected up and down without drilling out the bridge plug. The above-mentioned bridge plug has the following technical problems: the sealing effect of the bridge plug is unstable after the sealing is completed, and it cannot seal the current production layer, resulting in the bridge plug failing to play a sealing role, thereby making it impossible to carry out normal production. Summary of the invention

[0004] The purpose of the present invention is to provide a full-metal soluble bridge plug with a herringbone sealing structure and a sealing method, so as to solve the problem that the sealing effect of the existing bridge plug is unstable after the sealing is completed, and it cannot seal the current production layer, resulting in the bridge plug failing to play a sealing role, thereby making it impossible to carry out normal production.

[0005] To achieve the above-mentioned objectives, the present invention provides a full-metal soluble bridge plug with a herringbone plugging structure, comprising a core shaft and a pipe shaft sleeved on the outside of the core shaft, an upper cava assembly and a lower cava assembly sleeved on the outer surface of the pipe shaft, a lower cava pressing platform is arranged above the lower cava assembly, an upper cava pressing platform is arranged below the upper cava assembly, a herringbone plugging assembly is arranged between the upper cava pressing platform and the lower cava pressing platform, and the herringbone plugging assembly is sleeved at the middle position of the pipe shaft.

[0006] Preferably, an upper pressure ring is fixedly connected to the upper part of the upper slip assembly, and the upper pressure ring is sleeved on the upper end part of the pipe shaft.

[0007] Preferably, a lower pressure ring is fixedly connected to the lower part of the lower slip assembly, a positioning push sleeve is provided below the lower pressure ring, and the positioning push sleeve is sleeved on the lower end part of the pipe shaft.

[0008] Preferably, the upper slip assembly and the lower slip assembly respectively include an upper slip and a lower slip sleeved outside the pipe shaft. A plurality of cut surfaces are provided on the outer surfaces of the lower slip and the upper slip, and a plurality of anchoring teeth are provided on each cut surface. The longitudinal section of each anchoring tooth is arranged as a trapezoidal structure.

[0009] Preferably, the herringbone sealing assembly includes a \丿-shaped rubber sleeve arranged below the upper slip pressing platform and a \乀-shaped rubber sleeve arranged above the lower slip pressing platform. The \乀-shaped rubber sleeve and the \丿-shaped rubber sleeve are fixedly connected. The \丿-shaped pattern on the \丿-shaped rubber sleeve and the \乀-shaped pattern on the \乀-shaped rubber sleeve are joined to form a herringbone pattern.

[0010] Preferably, the top radius of the \丿-shaped rubber sleeve is greater than the bottom radius of the upper slip pressing platform. The bottom radius of the \丿-shaped rubber sleeve is the same as the upper radius of the \乀-shaped rubber sleeve. The bottom radius of the \乀-shaped rubber sleeve is greater than the top radius of the lower slip pressing platform.

[0011] Preferably, both the upper slip pressing platform and the lower slip pressing platform are arranged as conical structures. The tip of the upper slip pressing strip extends into the space between the upper slip and the pipe shaft, and the tip of the lower slip extends into the space between the lower slip and the pipe shaft.

[0012] A setting method for a herringbone sealing structure full-metal soluble bridge plug includes the following steps:

[0013] Step S1: Use the inner cylinder of the downhole operation plug delivery tool to hook and pull the core shaft connecting the bridge plug, and at the same time make the outer cylinder of the downhole operation plug delivery tool abut against the pipe shaft of the bridge plug;

[0014] Step S2: Push the pipe shaft in the direction of the bottom of the oil and gas well where the bridge plug is located by the outer cylinder, and hook and pull the core shaft in the opposite direction by the inner cylinder, so that the pipe shaft reaches the setting position;

[0015] Step S3: During the sliding of the pipe shaft, squeeze the upper pressing ring part of the bridge plug to the setting position. The upper pressing ring and the positioning push sleeve drive the upper slip assembly and the lower slip assembly to move towards the rubber barrel part during the process of reaching the setting position. After being squeezed by the slip assembly, the upper slip pressing platform and the lower slip pressing platform cause the anchoring teeth on the upper slip and the lower slip to be seated on the inner wall of the casing where the bridge plug is located under the action of the axial extrusion force jointly applied by the upper slip pressing platform, the lower slip pressing platform and the pipe shaft;

[0016] Step S4: During expansion, the \丿-shaped teeth and \乀-shaped teeth of the \丿-shaped rubber sleeve and the \乀-shaped rubber sleeve first contact the inner wall of the casing during the outward expansion process. During the continuous outward expansion process, the \丿-shaped teeth and \乀-shaped teeth cannot continue to expand radially outward, and are extruded and expanded along the tangent direction of the \丿-shaped teeth and \乀-shaped teeth to achieve tight setting;

[0017] Step S5: When the bridge plug is in the set state, the downhole operation plug delivery tool drives the mandrel to move relative to the positioning push sleeve to release the connection between the mandrel and the positioning push sleeve; after the connection is released, the mandrel is withdrawn from the central hole of the setting pipe shaft by using the downhole operation plug delivery tool to form an internal fluid passage of the bridge plug in the central hole of the pipe shaft.

[0018] Therefore, the present invention adopts the above-mentioned herringbone plugging structure all-metal soluble bridge plug and setting method, and has the following beneficial effects:

[0019] (1) For the bridge plug with the herringbone plugging structure designed by the present invention, the amount of material used for the rubber cylinder is greatly reduced, and the construction cost is greatly improved. This structure also provides new ideas for the innovation and use of the bridge plug structure.

[0020] (2) When the rubber cylinder of the bridge plug with the herringbone plugging structure designed by the present invention is dissolved, the contact area with the dissolution liquid is larger, which is more conducive to the rapid dissolution of the rubber cylinder, improves the work efficiency, and reduces the construction duration.

[0021] (3) The rubber cylinder of the bridge plug with the herringbone plugging structure designed by the present invention uses an alloy material with stronger dissolution ability. Compared with other metal materials, it not only has stronger ductility, but also has excellent characteristics such as easy processing, providing new ideas for the production and research of bridge plug materials.

[0022] Next, through the drawings and embodiments, the technical solutions of the present invention will be further described in detail. Description of the Drawings

[0023] Figure 1 It is a schematic structural diagram of an embodiment of a herringbone plugging structure all-metal soluble bridge plug and setting method of the present invention;

[0024] Figure 2 It is a cross-sectional view of an embodiment of a herringbone plugging structure all-metal soluble bridge plug and setting method of the present invention;

[0025] Reference numerals: 1, mandrel; 2, pipe shaft; 3, upper pressing ring; 4, upper slip assembly; 5, upper slip pressing platform; 6, \丿-shaped rubber sleeve; 7, \乀-shaped rubber sleeve; 8, lower slip pressing platform; 9, lower slip assembly; 10, lower pressing ring; 11, upper slip; 12, lower slip; 13, cutting surface; 14, anchoring teeth; 15, positioning push sleeve. Detailed Embodiments

[0026] The following further illustrates the technical solutions of the present invention through the drawings and embodiments.

[0027] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0028] Example

[0029] See also Figure 1-2 The present invention provides a full-metal soluble bridge plug with a herringbone plugging structure, comprising a core shaft 1 and a pipe shaft 2 sleeved on the outside of the core shaft 1, an upper slip assembly 4 and a lower slip assembly 9 sleeved on the outer surface of the pipe shaft 2, a lower slip platform 8 is arranged above the lower slip assembly 9, an upper slip platform 5 is arranged below the upper slip assembly 4, a herringbone plugging assembly is arranged between the upper slip platform 5 and the lower slip platform 8, and the herringbone plugging assembly is sleeved at the middle position of the pipe shaft 2.

[0030] An upper pressure ring 3 is fixedly connected to the upper part of the upper slip assembly 4, and the upper pressure ring 3 is sleeved on the upper end of the pipe shaft 2. A lower pressure ring 10 is fixedly connected to the lower part of the lower slip assembly 9, and a positioning push sleeve 15 is arranged below the lower pressure ring 10, and the positioning push sleeve 15 is sleeved on the lower end of the pipe shaft 2.

[0031] The upper slip assembly 4 and the lower slip assembly 9 respectively include an upper slip 11 and a lower slip 12 sleeved on the outside of the pipe axis 2, and the outer surfaces of the lower slip 12 and the upper slip 11 are provided with a plurality of cut surfaces 13, and each cut surface 13 is provided with a plurality of anchor teeth 14, and the longitudinal section of each anchor tooth 14 is provided with a trapezoidal structure. The upper slip pressing platform 5 and the lower slip pressing platform 8 are both provided with a conical structure, and the tip of the upper slip pressing platform 5 extends between the upper slip 11 and the pipe axis 2, and the tip of the lower slip 12 extends between the lower slip and the pipe axis 2.

[0032] When the upper slip assembly 4 is pressed, the upper slip pressing platform 5 is pressed downward, and the conical surface of the upper slip pressing platform 5 is engaged with the upper slip pressing platform 5. The conical surface of the lower slip pressing platform 8 faces downward, and the bottom end extends into between the lower slip assembly 9 and the pipe axis 2. The lower slip pressing platform 8 is pressed by the lower pressure ring 10, and the lower slip pressing platform 8 is forced to move upward.

[0033] The herringbone sealing assembly includes a zigzag rubber sleeve 6 arranged below the upper slip pressing platform 5 and a zigzag rubber sleeve 7 arranged above the lower slip pressing platform 8. The zigzag rubber sleeve 7 and the zigzag rubber sleeve 6 are fixedly connected, and the zigzag patterns on the zigzag rubber sleeve 6 and the zigzag patterns on the zigzag rubber sleeve 7 are connected to form a herringbone pattern.

[0034] The top radius of the ribbed rubber sleeve 6 is greater than the bottom radius of the upper slip platform 5. When the upper slip platform 5 is forced to move downward, the ribbed rubber sleeve 6 is pressed by the upper slip platform 5 and the ribbed rubber sleeve 7 to protrude, forming a ribbed sealing structure located above. The bottom radius of the ribbed rubber sleeve 6 is the same as the top radius of the ribbed rubber sleeve 7, and the bottom radius of the ribbed rubber sleeve 7 is greater than the top radius of the lower slip platform 8. When the lower slip platform 8 is forced to move upward, the ribbed rubber sleeve 7 is pressed by the lower slip platform 8 and the ribbed rubber sleeve 6 to protrude, forming a ribbed sealing structure located below.

[0035] A method for setting a herringbone plugging structure full metal soluble bridge plug comprises the following steps:

[0036] Step S1, using the inner tube of the downhole operation plug delivery tool to hook and pull the core shaft connected to the bridge plug, while making the outer tube of the downhole operation plug delivery tool press against the pipe shaft of the bridge plug;

[0037] Step S2, the outer tube pushes the pipe shaft toward the bottom of the oil and gas well where the bridge plug is located, and the inner tube hooks and pulls the core shaft in the opposite direction, so that the pipe shaft reaches the setting position;

[0038] Step S3, during the sliding process of the pipe shaft, the upper pressure ring part of the bridge plug is squeezed to the setting position, and the upper pressure ring and the positioning push sleeve drive the upper slip assembly and the lower slip assembly to move toward the rubber cylinder part during the process of reaching the setting position, and after the upper slip pressing platform and the lower slip pressing platform are squeezed by the slip assembly, the anchor teeth on the upper slip and the lower slip are set on the inner wall of the casing where the bridge plug is located under the action of the axial extrusion force jointly applied by the upper slip pressing platform and the lower slip pressing platform and the pipe shaft;

[0039] Step S4, during expansion, the grooved rubber sleeve and the grooved rubber sleeve's grooved teeth and the grooved teeth of the rubber sleeve first contact the inner wall of the casing during the outward expansion process, and in the process of continuing to expand outward, the grooved teeth and the grooved teeth cannot continue to radiate outward and expand along the tangent direction of the grooved teeth and the grooved teeth to achieve tight sealing;

[0040] Step S5: When the bridge plug is in the setting state, the downhole operation plug delivery tool drives the core shaft to move relative to the positioning sleeve to release the connection between the core shaft and the positioning sleeve; after the connection is released, the downhole operation plug delivery tool is used to extract the core shaft from the center hole of the setting pipe shaft so that the center hole of the pipe shaft forms the internal fluid channel of the bridge plug.

[0041] Therefore, the present invention adopts the above-mentioned herringbone plugging structure all-metal soluble bridge plug and setting method. When applying forces to the upper pressing ring and the lower pressing ring from both ends respectively, the expansion volume at the junction of the ∠-shaped rubber sleeve and the ∟-shaped rubber sleeve is the largest. Since the diameter of the outer pipe wall is fixed, when the junction expands to a certain volume, it expands towards the left and right ends, thereby achieving the effect of tight setting; the ∠-shaped rubber sleeve and the ∟-shaped rubber sleeve are fixed by bonding, which can prevent the components from falling off in the non-working state.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A herringbone plugging structure full metal soluble bridge plug, characterized by: It includes a core shaft and a pipe shaft sleeved on the outside of the core shaft, an upper slip assembly and a lower slip assembly are sleeved on the outer surface of the pipe shaft, a lower slip pressing platform is arranged above the lower slip assembly, an upper slip pressing platform is arranged below the upper slip assembly, a herringbone sealing assembly is arranged between the upper slip pressing platform and the lower slip pressing platform, and the herringbone sealing assembly is sleeved at the middle position of the pipe shaft.

2. The all-metal soluble bridge plug with herringbone plugging structure according to claim 1 is characterized by: An upper pressure ring is fixedly connected to the upper part of the upper slip assembly, and the upper pressure ring is sleeved on the upper end part of the pipe shaft.

3. The all-metal soluble bridge plug with herringbone plugging structure according to claim 2 is characterized by: A lower pressure ring is fixedly connected to the lower part of the lower slip assembly, and a positioning push sleeve is arranged below the lower pressure ring. The positioning push sleeve is sleeved on the lower end part of the pipe shaft.

4. The all-metal soluble bridge plug with a herringbone plugging structure according to claim 3 is characterized by: The upper cava assembly and the lower cava assembly respectively include an upper cava and a lower cava which are sleeved on the outside of the pipe axis. The outer surfaces of the lower cava and the upper cava are provided with a plurality of cut surfaces, each of the cut surfaces is provided with a plurality of anchoring teeth, and the longitudinal section of each of the anchoring teeth is provided with a trapezoidal structure.

5. The all-metal soluble bridge plug with herringbone plugging structure according to claim 4 is characterized by: The herringbone sealing assembly includes a zigzag rubber sleeve arranged below the upper slip platen and a zigzag rubber sleeve arranged above the lower slip platen, the zigzag rubber sleeve and the zigzag rubber sleeve are fixedly connected, and the zigzag patterns on the zigzag rubber sleeve and the zigzag patterns on the zigzag rubber sleeve are connected to form a herringbone pattern.

6. The all-metal soluble bridge plug with a herringbone plugging structure according to claim 5 is characterized by: The top radius of the ribbed rubber sleeve is larger than the bottom radius of the upper cava pressing platform, the bottom radius of the ribbed rubber sleeve is the same as the top radius of the ribbed rubber sleeve, and the bottom radius of the ribbed rubber sleeve is larger than the top radius of the lower cava pressing platform.

7. The all-metal soluble bridge plug with a herringbone plugging structure according to claim 6 is characterized by: The upper slip pressing platform and the lower slip pressing platform are both configured as conical structures, the tip of the upper slip pressing strip extends between the upper slip and the pipe axis, and the tip of the lower slip extends between the lower slip and the pipe axis.

8. A method for setting a herringbone plugging structure all-metal soluble bridge plug according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step S1, using the inner tube of the downhole operation plug delivery tool to hook and pull the core shaft connected to the bridge plug, while making the outer tube of the downhole operation plug delivery tool press against the pipe shaft of the bridge plug; Step S2, the outer tube pushes the pipe shaft toward the bottom of the oil and gas well where the bridge plug is located, and the inner tube hooks and pulls the core shaft in the opposite direction, so that the pipe shaft reaches the setting position; Step S3, during the sliding process of the pipe shaft, the upper pressure ring part of the bridge plug is squeezed to the setting position, and the upper pressure ring and the positioning push sleeve drive the upper slip assembly and the lower slip assembly to move toward the rubber cylinder part during the process of reaching the setting position, and after the upper slip pressing platform and the lower slip pressing platform are squeezed by the slip assembly, the anchor teeth on the upper slip and the lower slip are set on the inner wall of the casing where the bridge plug is located under the action of the axial extrusion force jointly applied by the upper slip pressing platform and the lower slip pressing platform and the pipe shaft; Step S4, during expansion, the grooved rubber sleeve and the grooved rubber sleeve's grooved teeth and the grooved teeth of the rubber sleeve first contact the inner wall of the casing during the outward expansion process, and in the process of continuing to expand outward, the grooved teeth and the grooved teeth cannot continue to radiate outward and expand along the tangent direction of the grooved teeth and the grooved teeth to achieve tight sealing; Step S5, when the bridge plug is in the sealing state, the downhole plug delivery tool drives the core shaft to move relative to the positioning push sleeve to release the connection between the core shaft and the positioning push sleeve; after the connection is released, the downhole plug delivery tool is used to extract the core shaft from the center hole of the sealing pipe shaft so that the center hole of the pipe shaft forms the internal fluid channel of the bridge plug.

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