Double-rubber-barrel self-sealing-examining bridge plug

Abstract

The utility model discloses a double-rubber-barrel self-examining sealing bridge plug, which belongs to the field of drilling tools and comprises a bridge plug and an internal sealing mechanism, the bridge plug comprises a guide ring, a central pipe, a first rubber barrel and a second rubber barrel, and a first runner hole is formed in the side wall of the central pipe. The first rubber sleeve and the second rubber sleeve are arranged on the outer wall of the central pipe in a sleeving mode and located on the two sides of the first flow channel hole respectively, the outer wall of one end of the central pipe is sleeved with the guide ring, the guide ring is used for moving along with the pumping pressure of a wellhead oil pipe and making the first rubber sleeve and the second rubber sleeve complete setting, and the inner sealing mechanism is arranged on the inner wall of the central pipe in a sliding sleeving mode. A second flow channel hole is formed in the side wall of the internal sealing mechanism, and the internal sealing mechanism moves in the direction away from the guide ring through continuous pumping pressure of an external wellhead oil pipe till the first flow channel hole communicates with the second flow channel hole, so that liquid in the internal sealing mechanism can flow into an annular space formed by the first rubber sleeve, the second rubber sleeve and the sleeve; and the setting effect of the bridge plug can be checked.

Description

Technical Field

[0001] The utility model relates to the technical field of drilling tools, in particular to a double-rubber tube self-testing and sealing bridge plug. Background Art

[0002] Bridge plug is an important tool for underground layered plugging. With the accumulation of oilfield production and development time, the number of multi-perforation sections and multi-set damaged old wells increases year by year. The treatment method is to use cast iron bridge plugs that can be quickly milled for layered plugging. After the bridge plug is set, the sealing performance is verified by upper pressure. For example, the utility model patent for a self-testing fracturing bridge plug with authorization announcement number CN202882843U includes a center pipe, a piston, an upper sealing rubber cylinder, and a lower sealing rubber cylinder. A sealing sleeve and a sealing shear are provided between the upper sealing rubber cylinder and the lower sealing rubber cylinder. The seal inspection pins and the seal inspection piston, the seal inspection sleeve, the seal inspection shear pins and the seal inspection piston are all mounted on the center pipe. When the bridge plug is lowered to the designed well depth, water is injected to pressurize the piston, and the upper and lower sealant tubes are squeezed upward to seal the bridge plug. After the sealing is completed, the oil pipe is pressurized continuously. When the pressure rises to a certain value, the seal inspection shear pins are cut off, and the hydraulic pressure pushes the seal inspection piston downward. The liquid enters the annular cavity formed by the lower and upper sealant tubes and the casing through the first seal inspection hole on the center pipe and the second seal inspection hole on the seal inspection sleeve, so as to test the sealing performance of the lower and upper sealant tubes.

[0003] However, when the bridge plug fails to be set and the staff continues to test the seal by pressing the oil pipe, the annular cavity formed by the lower sealing rubber cylinder, the upper sealing rubber cylinder and the casing is in a non-sealed state due to incomplete sealing. As a result, the sealing shear pins cannot be cut off even though the preset pressure shear value is reached. If the staff continues to pressurize the oil pipe blindly, it may cause damage to the upper and lower sealing rubber cylinders and even cause a safety accident. Utility Model Content

[0004] In view of this, it is necessary to provide a double-rubber-tube self-sealing bridge plug to solve the technical problem in the prior art that the staff cannot promptly detect the failure of the bridge plug to seal.

[0005] The utility model provides a double rubber tube self-testing and sealing bridge plug, comprising:

[0006] A bridge plug, the bridge plug comprising a guide ring, a center tube, a first rubber tube and a second rubber tube, the side wall of the center tube is provided with a first flow channel hole, the first rubber tube and the second rubber tube are both sleeved on the outer wall of the center tube and are respectively located on both sides of the first flow channel hole, the guide ring is sleeved on the outer wall of one end of the center tube, the guide ring is used to move with the pump pressure of the wellhead oil pipe, and enable the first rubber tube and the second rubber tube to complete the sealing;

[0007] The internal sealing mechanism is slidably sleeved on the inner wall of the central tube, and a second flow channel hole is opened on the side wall of the internal sealing mechanism.

[0008] In one of the embodiments, a sealing pin is provided between the inner wall of the guide ring and the outer wall of the central tube.

[0009] In one embodiment, a sealing ring is provided between the first rubber tube and the second rubber tube, and the sealing ring is sleeved on the outer wall of the central tube.

[0010] In one embodiment, the ends of the first rubber cylinder and the second rubber cylinder which are away from each other are respectively provided with a first cone, a second cone, a first slip and a second slip, the first cone, the second cone, the first slip and the second slip are all sleeved on the outer wall of the center tube, and the guide ring is located in the direction where the first slip is away from the first cone.

[0011] In one of the embodiments, an upper joint is provided at the end of the guide ring facing away from the first slip, and the internal sealing mechanism is detachably connected to the upper joint.

[0012] In one embodiment, the internal sealing mechanism includes a lower insert tube, an insert tube sealing assembly, a ball seat seating tube and a shear ball seat. The lower insert tube, the insert tube sealing assembly and the ball seat seating tube are sequentially connected from top to bottom, and the shear ball seat is slidably sleeved on the inner wall of the lower insert tube.

[0013] In one of the embodiments, a sealing shear annular groove is provided on the outer wall of the lower insert, and a sealing pin is provided on the inner wall of the upper joint, and the sealing pin is embedded in the sealing shear annular groove.

[0014] In one of the embodiments, a locking member is provided between the guide ring and the first slip, and the locking member is sleeved on the outer wall of the central tube.

[0015] In one of the embodiments, a guide shoe is provided at one end of the central tube away from the guide ring.

[0016] In one of the embodiments, a sealing ring is provided on the outer wall of the end of the central tube facing the guide shoe.

[0017] Compared with the prior art, the double-rubber-tube self-sealing bridge plug provided by the utility model has the following beneficial effects:

[0018] When setting, the internal sealing mechanism blocks the center tube (i.e., the second flow channel hole is blocked by the inner wall of the center tube), so that when the external wellhead oil pipe is pumped, it will only push the guide ring to move and compress the first rubber cylinder and the second rubber cylinder until the bridge plug is set;

[0019] During self-sealing inspection, the continuous pumping pressure of the external wellhead oil pipe causes the internal sealing mechanism to move away from the guide ring until the first flow channel hole is connected to the second flow channel hole, so that the liquid in the internal sealing mechanism can flow into the annulus formed by the first rubber cylinder, the second rubber cylinder and the casing, and the sealing effect of the bridge plug can be inspected. Once the sealing inspection value is abnormal, the staff can immediately know that the bridge plug has failed to be sealed, which effectively improves the sealing inspection efficiency of the bridge plug.

[0020] The above description is only an overview of the technical solution of the utility model. In order to more clearly understand the technical means of the utility model and implement it according to the contents of the specification, the preferred embodiments of the utility model are described in detail as follows in conjunction with the accompanying drawings. The specific implementation method of the utility model is given in detail by the following embodiments and their drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present application. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

[0022] Figure 1 An isometric schematic diagram of a double-rubber-tube self-sealing bridge plug provided by the utility model;

[0023] Figure 2 for Figure 1 A partial cross-sectional view of the middle bridge plug;

[0024] Figure 3 It is an isometric schematic diagram of an internal sealing mechanism in a double-rubber-tube self-sealing bridge plug provided by the utility model;

[0025] Figure 4 for Figure 3 A cross-sectional view of the internal sealing mechanism;

[0026] Figure 5 A partial cross-sectional view of a double-rubber self-sealing bridge plug provided by the utility model (in the self-sealing operation state);

[0027] Figure 6 for Figure 5 A magnified schematic diagram of the local A in the middle;

[0028] Figure 7 A cross-sectional view of a double-rubber-tube self-sealing bridge plug provided by the utility model (under cement operation state).

[0029] The reference numerals are as follows: 1, bridge plug; 11, guide ring; 111, seal inspection pin; 12, center tube; 121, first flow channel hole; 13, first rubber cylinder; 131, first cone; 1311, first pin; 132, first slip; 14, second rubber cylinder; 141, second cone; 1411, second pin; 142, second slip; 15, guide shoe; 151, sealing ring; 16, seal inspection ring; 161, third flow channel hole; 16 2. Flow channel cavity; 17. Locking piece; 18. Upper joint; 181. Sealing pin; 2. Internal sealing mechanism; 21. Lower insert; 211. Sealing shear annular groove; 22. Insert seal assembly; 23. Ball seat seating cylinder; 231. Second flow channel hole; 24. Shear ball seat; 25. Shear pin; 26. Steel ball; 3. Casing; 4. Sliding valve; 41. U-shaped groove; 5. Cement retainer guide shoe; 51. Mud injection through hole; B. Liquid flow direction. DETAILED DESCRIPTION

[0030] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0031] See also Figure 1-Figure 7 The utility model provides a double rubber tube self-sealing bridge plug 1, comprising:

[0032] The bridge plug 1 comprises a guide ring 11, a center tube 12, a first rubber tube 13 and a second rubber tube 14. A first flow channel hole 121 is provided on the side wall of the center tube 12. The first rubber tube 13 and the second rubber tube 14 are both sleeved on the outer wall of the center tube 12 and are respectively located on both sides of the first flow channel hole 121. The guide ring 11 is sleeved on the outer wall of one end of the center tube 12. The guide ring 11 is used to move with the pump pressure of the wellhead oil pipe and enable the first rubber tube 13 and the second rubber tube 14 to complete the sealing.

[0033] The internal sealing mechanism 2 is slidably sleeved on the inner wall of the central tube 12 , and a second flow channel hole 231 is opened on the side wall of the internal sealing mechanism 2 .

[0034] Specifically, when setting, the internal sealing mechanism 2 blocks the central tube 12 (i.e., the second flow channel hole 231 is blocked by the inner wall of the central tube 12), so that when the external wellhead oil pipe is pumped, it will only push the guide ring 11 to move and compress the first rubber cylinder 13 and the second rubber cylinder 14 until the bridge plug 1 is set;

[0035] During the self-sealing test, the internal sealing mechanism 2 is moved away from the guide ring 11 through the continuous pumping pressure of the external wellhead oil pipe until the first flow channel hole 121 is connected with the second flow channel hole 231, so that the liquid in the internal sealing mechanism 2 can flow into the annulus formed by the first rubber cylinder 13, the second rubber cylinder 14 and the casing 3, and the sealing effect of the bridge plug 1 can be tested. Once the sealing test value is abnormal, the staff can immediately know that the bridge plug 1 has failed to be sealed, which effectively improves the sealing test efficiency of the bridge plug 1.

[0036] Firstly, during sealing, the internal sealing mechanism 2 is inserted into the central tube 12 and blocks the central tube 12, so that when the external wellhead oil pipe is pumped, the guide ring 11 moves downward and compresses the first rubber cylinder 13 and the second rubber cylinder 14 until the sealing of the bridge plug 1 is completed; then, during self-sealing, the internal sealing mechanism 2 moves away from the guide ring 11 through the continuous pumping pressure of the external wellhead oil pipe until the interior of the internal sealing mechanism 2 can be connected with the annulus formed by the first rubber cylinder 13, the second rubber cylinder 14 and the casing 3 through the first flow channel hole 121 and the second flow channel hole 231; finally, the liquid can enter the annulus after passing through the first flow channel hole 121 and the second flow channel hole 231 from the internal sealing mechanism 2 in sequence, and judge whether the sealing is qualified by the pressure drop within a specific time, so as to achieve the goal of self-sealing.

[0037] It should be noted that the first rubber cylinder 13 and the second rubber cylinder 14 are both composed of an outer back ring, an inner back ring, an upper rubber cylinder, a retaining ring and an auxiliary sealing O-ring.

[0038] Furthermore, in this embodiment, a seal checking pin 111 is provided between the inner wall of the guide ring 11 and the outer wall of the central tube 12. Specifically, the guide ring 11 is fixed to the outer wall of the central tube 12 by the seal checking pin 111.

[0039] Furthermore, in this embodiment, a seal inspection ring 16 is provided between the first rubber cylinder 13 and the second rubber cylinder 14, and the seal inspection ring 16 is sleeved on the outer wall of the central tube 12. Specifically, the side wall of the seal inspection ring 16 is provided with a third flow channel hole 161 and a flow channel cavity 162, and forms a seal inspection channel with the first flow channel hole 121 and the second flow channel hole 231 on the central tube 12 (the seal inspection liquid will flow along with the seal inspection liquid). Figure 6 Injection in the direction marked with B).

[0040] Furthermore, in the present embodiment, the ends of the first rubber cylinder 13 and the second rubber cylinder 14 which are away from each other are respectively provided with a first cone 131, a second cone 141, a first cava 132 and a second cava 142. The first cone 131, the second cone 141, the first cava 132 and the second cava 142 are all sleeved on the outer wall of the center tube 12, and the guide ring 11 is located in the direction where the first cava 132 is away from the first cone 131. Specifically, the first cone 131 is fixed to the outer wall of the central tube 12 by the first pin 1311, and the second cone 141 is fixed to the outer wall of the central tube 12 by the second pin 1411. After the bridge plug 1 is lowered to the specified position, the internal sealing mechanism 2 blocks the central tube 12, and the hydraulic sealing tool applies continuous thrust to the guide ring 11 through the wellhead oil pipe. The sealing pin 111, the first pin 1311 and the second pin 1411 are cut off in sequence, and the guide ring 11 moves downward along the axial direction of the central tube 12. Finally, the first cone 131 pushes the first slip 132 and the second cone 141 pushes the second slip 142, so that they move radially respectively until they are anchored on the inner wall of the casing 3. At the same time, the first rubber cylinder 13 and the second rubber cylinder 14 are further compressed until the first rubber cylinder 13, the second rubber cylinder 14 and the casing 3 form a cavity for easy sealing.

[0041] Furthermore, in order to prevent the bridge plug 1 from rotating during the setting process and affecting the setting effect, a guide key is provided between the second cone 141 and the second slip 142 .

[0042] Further, in this embodiment, an upper joint 18 is provided at the end of the guide ring 11 away from the first slip 132, and the internal sealing mechanism 2 is detachably connected to the upper joint 18. Specifically, the function of the upper joint 18 is to connect the bridge plug 1 with a specific hydraulic setting tool so that it can be lowered into the well along with the oil pipe.

[0043] Furthermore, in this embodiment, the internal sealing mechanism 2 includes a lower insert tube 21, an insert tube sealing assembly 22, a ball seat seating cylinder 23 and a shear ball seat 24. The lower insert tube 21, the insert tube sealing assembly 22 and the ball seat seating cylinder 23 are sequentially connected from top to bottom, and the shear ball seat 24 is slidably sleeved on the inner wall of the lower insert tube 21. Specifically, the function of the lower insert tube 21 is to be threadedly connected with an external specific hydraulic sealing tool. The initial state of the shear ball seat 24 is to be fixedly connected with the inner wall of the lower insert tube 21 through the ball seat shear pin 25. When the bridge plug 1 is lowered to the specified position, the steel ball 26 is dropped into the shear ball seat 24 to form a ball seal, which is convenient for the pump pressure of the external wellhead oil pipe, so that the hydraulic sealing tool applies continuous thrust to the guide ring 11, and the bridge plug 1 starts to be sealed.

[0044] Furthermore, a second flow channel hole 231 is opened on the side wall of the ball seat seating tube 23. After the bridge plug 1 is sealed, the internal sealing mechanism 2 is lifted up, and when the internal sealing mechanism 2 is completely separated from the bridge plug 1, the pump pressure is re-applied to cut off the ball seat shear pin 25, and the steel ball 26 and the shear ball seat 24 fall into the ball seat seating tube 23 together. The pump pressure is stopped, and the internal sealing mechanism 2 is reinserted into the center tube 12 until the liquid in the ball seat seating tube 23 can pass through the second flow channel hole 231 and sequentially pass through the first flow channel hole 121, the flow channel cavity 162 and the second flow channel hole 231 and then enter the cavity formed by the first rubber cylinder 13, the second rubber cylinder 14 and the sleeve 3.

[0045] Furthermore, in order to facilitate the processing and assembly of the ball seat shear pin 25 , a ball seat shear ring is provided between the lower insert pipe 21 and the shear ball seat 24 .

[0046] Furthermore, in this embodiment, a sealing shear annular groove 211 is provided on the outer wall of the lower insert 21, and a sealing pin 181 is provided on the inner wall of the upper joint 18, and the sealing pin 181 is embedded in the sealing shear annular groove 211. Specifically, after the internal sealing mechanism 2 is inserted into the central tube 12, it is fixed by the sealing shear annular groove 211 and the sealing pin 181 being engaged with each other.

[0047] Furthermore, after the bridge plug 1 is set, the pump pressure is continued until the setting pin 181 is sheared off, and the internal sealing mechanism 2 is separated from the inside of the bridge plug 1 under the action of the pump pressure, so that the bridge plug 1 is not affected when the shear ball seat 24 is pressed.

[0048] Furthermore, in this embodiment, a locking member 17 is provided between the guide ring 11 and the first slip 132, and the locking member 17 is sleeved on the outer wall of the central tube 12. Specifically, the guide ring 11 is connected to the locking member 17 by a threaded connection, and the function of the locking member 17 is to ensure that the first rubber cylinder 13 and the second rubber cylinder 14 do not rebound after pressure relief.

[0049] It should be noted that the locking member 17 includes a locking ring and a locking ring seat, and the contact surfaces of the locking ring and the locking ring seat are provided with serrated grooves. As the guide ring 11 pushes the locking member 17 to continuously move axially, the locking ring moves downward along the serrated groove on the center tube 12. The serrated groove structure ensures that the first rubber cylinder 13 and the second rubber cylinder 14 do not rebound after pressure relief. When the pump pressure reaches a certain value, the bridge plug 1 is completely sealed.

[0050] Furthermore, in this embodiment, a guide shoe 15 is provided at one end of the center pipe 12 away from the guide ring 11. Specifically, the guide shoe 15 is fixedly connected to the center pipe 12 by a set screw to ensure the sealing of the end of the center pipe 12 during the setting process of the bridge plug 1.

[0051] Furthermore, in order to improve the practicality of the device, a sliding valve 4 is added inside the guide shoe 15, and a mud injection hole 51 is opened on the side wall of the guide shoe 15 to form a cement retainer guide shoe 5. By exchanging the guide shoe 15 with the cement retainer guide shoe 5, the bridge plug 1 and the cement retainer can be quickly switched to achieve cement squeezing operation, wherein the function of the sliding valve 4 is to control whether the mud injection hole 51 is connected to the second flow channel hole 231.

[0052] Furthermore, the sliding valve 4 is provided with a plurality of U-shaped grooves 41 at the end of the ball seat seating tube 23, and each U-shaped groove 41 is arranged at equal intervals along the circumference of the cross section of the sliding valve 4. The initial state of the sliding valve 4 is located at the upper end of the mud injection through hole 51, which is used to prevent the liquid in the ball seat seating tube 23 from leaking into the cement retainer guide shoe 5. When cement action is required, the external wellhead oil pipe is continuously pumped, and the steel ball 26 shears the ball seat 24 to drive the ball seat seating tube 23 to insert into the sliding valve 4, and drives the sliding valve 4 to move toward the cement retainer guide shoe 5 until the second flow channel hole 231 is connected to the mud injection through hole 51 through the U-shaped groove 41, and the cement can pass through the second flow channel hole 231, the U-shaped groove 41 and the mud injection through hole 51 in sequence and then be discharged to the designated position.

[0053] Furthermore, in this embodiment, a sealing ring 151 is provided on the outer wall of the central pipe 12 facing the guide shoe 15. Specifically, the sealing ring 151 is used to prevent liquid leakage and improve the sealing performance during the setting process of the bridge plug 1.

[0054] The specific working process of the utility model is as follows: first, when setting the seal, the upper joint 18 is connected to the external hydraulic setting tool, the internal sealing mechanism 2 is inserted into the central tube 12, and is fixed with the setting pin 181 through the setting shear annular groove 211, and the steel ball 26 is dropped into the shear ball seat 24 to form a ball seal for blocking the central tube 12. After the bridge plug 1 is lowered to the specified position, the external wellhead oil pipe starts to pump pressure, the guide ring 11 moves downward and compresses the first rubber cylinder 13 and the second rubber cylinder 14, and the locking member 17 ensures that the first rubber cylinder 13 and the second rubber cylinder 14 do not rebound after the pressure is released. When the pressure reaches a specific value, the sealing pin 111 is sheared off, and the setting is completed;

[0055] Then, during the self-sealing test, the pipe column is lifted up a certain distance to separate the internal sealing mechanism 2 from the bridge plug 1 (at this time, the sealing pin 181 is sheared off), and water injection and pressure are continued to knock down the shear ball seat 24 and seat it on the ball seat seating cylinder 23;

[0056] Finally, stop pressurizing and push down the pipe column to reinsert the internal sealing mechanism 2 into the center pipe 12 until the first flow channel hole 121 is connected with the second flow channel hole 231, so that the liquid in the internal sealing mechanism 2 can enter the annulus formed by the first rubber tube 13, the second rubber tube 14 and the casing 3, and the sealing effect of the bridge plug 1 can be tested by continuously pumping for several minutes, thereby realizing self-sealing.

[0057] The above are only preferred specific implementation methods of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims

1. A double-rubber self-sealing bridge plug, characterized in that: include: A bridge plug, the bridge plug comprising a guide ring, a center tube, a first rubber tube and a second rubber tube, the side wall of the center tube is provided with a first flow channel hole, the first rubber tube and the second rubber tube are both sleeved on the outer wall of the center tube and are respectively located on both sides of the first flow channel hole, the guide ring is sleeved on the outer wall of one end of the center tube, the guide ring is used to move with the pump pressure of the wellhead oil pipe, and enable the first rubber tube and the second rubber tube to complete the sealing; The internal sealing mechanism is slidably sleeved on the inner wall of the central tube, and a second flow channel hole is opened on the side wall of the internal sealing mechanism.

2. A double-rubber self-sealing bridge plug according to claim 1, characterized in that: A sealing pin is arranged between the inner wall of the guide ring and the outer wall of the central tube.

3. The double-rubber self-sealing bridge plug according to claim 1 is characterized in that: A sealing ring is provided between the first rubber tube and the second rubber tube, and the sealing ring is sleeved on the outer wall of the central tube.

4. The double-rubber self-sealing bridge plug according to claim 1 is characterized in that: The ends of the first rubber cylinder and the second rubber cylinder which are away from each other are respectively provided with a first cone, a second cone, a first slip and a second slip. The first cone, the second cone, the first slip and the second slip are all sleeved on the outer wall of the central tube, and the guide ring is located in the direction where the first slip is away from the first cone.

5. The double-rubber self-sealing bridge plug according to claim 4 is characterized in that: An upper joint is provided at the end of the guide ring away from the first slip, and the internal sealing mechanism is detachably connected to the upper joint.

6. A double-rubber self-sealing bridge plug according to claim 5, characterized in that: The internal sealing mechanism includes a lower insert tube, an insert tube sealing assembly, a ball seat seating tube and a shear ball seat. The lower insert tube, the insert tube sealing assembly and the ball seat seating tube are sequentially connected from top to bottom, and the shear ball seat is slidably sleeved on the inner wall of the lower insert tube.

7. A double-rubber self-sealing bridge plug according to claim 6, characterized in that: A sealing shear annular groove is formed on the outer wall of the lower insert, and a sealing pin is formed on the inner wall of the upper joint. The sealing pin is embedded in the sealing shear annular groove.

8. The double-rubber self-sealing bridge plug according to claim 4 is characterized in that: A locking piece is provided between the guide ring and the first slip, and the locking piece is sleeved on the outer wall of the central tube.

9. The double-rubber self-sealing bridge plug according to claim 1, characterized in that: A guide shoe is provided at one end of the central tube away from the guide ring.

10. A double-rubber self-sealing bridge plug according to claim 9, characterized in that: A sealing ring is sleeved on the outer wall of the central tube facing one end of the guide shoe.

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