Open hole packer for leakage finding and plugging

Abstract

The open hole packer comprises an upper connector, the lower portion of the upper connector is connected with a center pipe through threads, the outer surface of the upper connector is connected with a reversing outer cylinder through a deblocking shear pin, the center pipe is sleeved with a rubber cylinder assembly, the upper connector is connected with a closing piston through a closing shear pin, and the closing piston is connected with a rubber sleeve. A liquid injection piston is fixedly connected to the center pipe through a starting shear pin, and a plurality of pressure relief grooves are formed in the outer surface of the lower portion of the center pipe. The long rubber sleeve packer capable of being unsealed by multiple times of setting solves the problem of multi-time drilling of leakage finding and leakage stopping of an existing packer, improves operation efficiency, overcomes the problem that the existing packer needs to damage a rubber sleeve to unseal and pull out a hole, reduces the occurrence probability of underground complexity, has the advantages of being simple in structure, high in safety and the like, and is suitable for popularization and application. Meanwhile, leakage finding and leaking stoppage of multiple leakage points can be achieved through one-time drilling, the purpose of accurate leaking stoppage in the well drilling process is achieved, and the well drilling leaking stoppage success rate is increased.

Description

Technical Field

[0001] The utility model belongs to the technical field of well drilling and well repair, and in particular relates to an open hole packer for leak detection and plugging. Background Art

[0002] Formation leakage during the drilling process is inevitable, which affects the progress of drilling operations and increases the drilling cycle. Drilling fluid entering the formation can easily cause pollution. It can also cause formation collapse, stuck drill, overflow blowout and other complex derivatives, increasing operation costs and difficulty.

[0003] In order to plug the leak, it is necessary to accurately find the location of the leakage layer and inject the plugging medium into the formation. The current common practice is to use general plugging. This method cannot overcome the problem of different water absorption of formations in different pressure systems. The plugging efficiency and success rate are low. Using tools to find leaks requires multiple trips in the drill, and it is impossible to achieve multiple sealing and release of the packer, resulting in low construction efficiency. Utility Model Content

[0004] The utility model aims to provide an open hole packer for leak detection and plugging, so as to solve the technical problems raised in the background technology.

[0005] To achieve the above-mentioned purpose, the specific technical solution of the utility model is as follows: an open hole sealer for leak detection and plugging, comprising an upper joint, the lower part of the upper joint is connected to a center tube by a thread, the outer surface of the upper joint is connected to a reversing outer tube by an unsealing shear pin, a rubber cylinder assembly is sleeved on the center tube, a closing piston is connected to the upper joint by a closing shear pin, an injection piston is fixedly connected to the center tube by a starting shear pin, a plurality of pressure relief grooves are provided on the lower outer surface of the center tube, the rubber cylinder assembly is connected to a lower floating ring by a thread, and one end of the center tube is connected to a lower joint by a thread.

[0006] Preferably, the upper portion of the upper joint is provided with threads.

[0007] Preferably, a guide pin is provided on the upper joint, an L-shaped reversing groove is provided on the reversing outer cylinder, and the guide pin is slidably connected to the reversing groove.

[0008] Preferably, shear nail holes are evenly arranged on the upper portion of the reversing outer cylinder, and shear nail grooves corresponding to the shear nail holes are provided on the upper joint.

[0009] Preferably, two groups of pressure transmission holes are axially arranged on the upper part of the central tube.

[0010] Preferably, an anti-retraction retaining spring is provided on the inner side of the closing piston.

[0011] Preferably, the rubber cylinder assembly consists of an upper rubber cylinder gauge ring, a lower rubber cylinder gauge ring and a rubber cylinder. The upper rubber cylinder gauge ring and the lower rubber cylinder gauge ring are located at both ends of the rubber cylinder. The upper rubber cylinder gauge ring is connected to the reversing outer cylinder, and the lower rubber cylinder gauge ring is threadedly connected to the lower floating ring.

[0012] Preferably, a sealing ring is provided on the inner side of the lower floating ring, and the sealing ring is sleeved on the outer side of the central tube.

[0013] The utility model is a kind of open hole packer for leak detection and plugging, which has the following advantages:

[0014] 1. The utility model solves the problem of multiple drilling trips for leak detection and plugging of existing packers, improves operating efficiency, overcomes the difficulty of existing packers requiring the destruction of the rubber tube to unseal and start drilling, and reduces the probability of complicated downhole situations. The multi-sealable long rubber tube packer has the advantages of simple structure and high safety. At the same time, it can realize leak detection and plugging of multiple leaks in one drilling trip, achieve the purpose of accurate plugging during drilling, and improve the success rate of drilling plugging.

[0015] 2. The utility model realizes multiple setting of the packer through a two-stage piston design and shear pins of different pressure levels. Multiple setting can meet the needs of multiple formation tests and can also realize the locking and setting of the packer rubber cylinder. After locking and setting, the rubber cylinder can withstand the upper and lower annular pressures. Through the unique reversing outer cylinder design, the piston force will not be applied to the unsealing shear pins when it is subjected to upward pressure, thereby preventing unsealing misoperation. The locked setting state of the packer can only be released after it is rotated and lifted. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0017] Figure 1 It is a schematic diagram of the overall structure of the utility model;

[0018] Explanation of the marks in the figure: 1. Upper joint; 2. Unsealing shear pin; 3. Reversing outer cylinder; 4. Reversing groove; 5. Guide pin; 6. Closing shear pin; 7. Closing piston; 8. Anti-retraction retaining spring; 9. Starting shear pin; 10. Injection piston; 11. Gauge ring of upper rubber cylinder; 12. Rubber cylinder; 13. Gauge ring of lower rubber cylinder; 14. Lower floating ring; 15. Pressure relief groove; 16. Lower joint; 17. Sealing ring; 18. Center tube. DETAILED DESCRIPTION

[0019] Hereinafter, only certain exemplary embodiments are briefly described. As will be appreciated by those skilled in the art, the described embodiments may be modified in various ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and description are to be regarded as illustrative in nature and not restrictive.

[0020] In the description of the embodiments of the present invention, it should be understood that the terms "length", "vertical", "horizontal", "top", "bottom", etc. indicating the orientation or position relationship are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying 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 on the embodiments of the present invention.

[0021] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0022] In the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0023] The disclosure below provides many different embodiments or examples for implementing different structures of the embodiments of the present invention. In order to simplify the disclosure of the embodiments of the present invention, the components and settings of specific examples are described below. Of course, these are merely examples and are not intended to limit the embodiments of the present invention. In addition, the embodiments of the present invention may repeat reference numbers and / or reference letters in different examples. Such repetition is for the purpose of simplicity and clarity and does not in itself indicate the relationship between the various embodiments and / or settings discussed.

[0024] In order to better understand the purpose, structure and function of the present invention, the following is a further detailed description of the open hole packer for leak detection and plugging of the present invention in conjunction with the accompanying drawings.

[0025] like Figure 1As shown, the utility model is an open hole packer for leak detection and plugging, comprising an upper joint 1, the upper portion of which is provided with threads for connection to an oil pipe or drill pipe when lowered, the lower portion of which is connected to a central pipe 18 via threads, the outer surface of the upper joint 1 being connected to a reversing outer tube 3 via an unsealing shear pin 2, the upper joint 1 being provided with a guide pin 5, the reversing outer tube 3 being provided with an L-shaped reversing groove 4, the guide pin 5 being slidably connected to the reversing groove 4, and the reversing groove 4 being used to determine the relative position of the rubber sleeve 12 and the central pipe 18, thereby placing the rubber sleeve 12 in a set or unsealed state. The upper portion of the reversing outer tube 3 is evenly distributed with shear pin holes, and the upper joint 1 is provided with shear pin grooves corresponding to the shear pin holes, so that the reversing outer tube 3 is positioned and fixed to the outer surface of the upper joint 1 via the unsealing shear pin 2. Shearing of the unsealing shear pin 2 can disengage the upper joint 1 and the reversing outer tube 3, thereby relieving the internal pressure of the rubber sleeve 12 and unsealing the packer. The center tube 18 is fitted with a rubber sleeve assembly. The upper connector 1 is connected to a closing piston 7 via a closing shear pin 6. When the closing shear pin 6 is sheared under pressure, the closing piston 7 is activated. An anti-retraction retaining spring 8 is provided inside the closing piston 7, locking it in place after actuation to prevent it from retracting. An injection piston 10 is fixedly connected to the center tube 18 via a starting shear pin 9. Once the starting shear pin 9 is sheared, the injection piston 10 is activated, allowing liquid within the center tube 18 to enter the rubber sleeve 12 through the injection piston 10, causing it to expand. The expanded rubber sleeve 12 then adheres to the wellbore wall to achieve a seal. The lower outer surface of the center tube 18 is provided with multiple pressure relief grooves 15. The rubber sleeve assembly is threadedly connected to a lower floating ring 14. A sealing ring 17 is provided inside the lower floating ring 14. The sealing ring 17 is sleeved onto the outside of the center tube 18 and forms a seal with the center tube 18. One end of the center tube 18 is threadedly connected to a lower connector 16, the lower portion of which is threadedly connected to other tools in the tubing string.

[0026] There are two groups of pressure transmission holes arranged axially on the upper part of the central tube 18. The lower pressure transmission hole is used to start the injection piston 10 when the pressure in the pipe is accumulated. After starting, the rubber tube 12 expands and seals. After the pressure in the pipe is released, the internal pressure of the rubber tube 12 is released and unsealed through the lower pressure transmission hole. During the leak detection process, the position of the leakage layer can be accurately determined by multiple sealing and pressure testing of the annulus. Once the leakage point is determined, the pressure in the pipe can be increased, the closing piston 7 can be activated, and the sealing state can be locked. At this time, the packer can withstand the upper or lower pressure difference and perform construction operations such as injecting plugging slurry. There are multiple pressure relief grooves 15 on the outer surface of the lower part of the central tube 18. After assembly, the sealing ring at the upper floating ring of the pressure relief groove 15 prevents the liquid in the rubber tube 12 from contacting the pressure relief groove 15. Once it is lifted up and unsealed, the internal pressure of the rubber tube 12 is unloaded through the pressure relief groove 15.

[0027] The rubber cylinder assembly consists of an upper rubber cylinder gauge ring 11, a lower rubber cylinder gauge ring 13 and a rubber cylinder 12. The upper rubber cylinder gauge ring 11 and the lower rubber cylinder gauge ring 13 are located at both ends of the rubber cylinder 12. The upper rubber cylinder gauge ring 11 is connected to the reversing outer cylinder 3, and the lower rubber cylinder gauge ring 13 is threadedly connected to the lower floating ring 14. The upper rubber cylinder gauge ring 11 and the lower rubber cylinder gauge ring 13 are vulcanized into a whole with the rubber cylinder 12. The rubber cylinder 12 usually has a deformable sealing section of more than 900mm, which can better adapt to irregular wellbore sealing.

[0028] The working process of open hole packer for leak detection and plugging is as follows:

[0029] (1) When the packer is lowered into place for expansion sealing, the wellhead pumps liquid, and the pressure in the center tube 18 cuts the starting shear pin 9. The injection piston 10 moves to the right under the action of the hydraulic pressure, and the liquid enters the rubber cylinder 12 through the injection channel, thereby achieving the expansion sealing of the rubber cylinder 12. As the rubber cylinder 12 expands radially and shrinks in axial length, the lower floating ring 14 moves upward until the rubber cylinder 12 fully squeezes the well wall, and then the movement stops. After the center tube 18 is depressurized, the injection piston 10 does not retreat, and the liquid inside the rubber cylinder 12 is depressurized and returns to the center tube 18, achieving unsealing;

[0030] (2) Repeating the above actions can achieve multiple times of setting and releasing seals, and formation testing can be carried out in conjunction with annular pressure holding;

[0031] (3) When the final sealing position is determined and the packer needs to be locked and sealed, liquid is pumped into the wellhead, and the pressure in the central tube 18 is built up. The pressure exceeds the shear pin pressure of the first injection piston by 8-12 MPa, shearing the closing shear pin 6 of the closing piston 7. The closing piston 7 moves to the right under the action of the hydraulic pressure, closing the injection channel on the central tube 18, thereby achieving the locking and expansion sealing of the rubber cylinder 12. At this time, the central tube 18 is depressurized, and the liquid in the rubber cylinder 12 is retained, always maintaining the pressure-holding expansion sealing state. In conjunction with the pumping operation in the pipe or annulus, leak plugging or testing operations can be achieved.

[0032] After the operation is completed, when it is necessary to unseal, it is only necessary to rotate the pipe string forward by a certain angle and switch the guide pin 5 of the upper joint 1 from the horizontal part of the L-shaped reversing groove 4 of the reversing outer cylinder 3 to the vertical part. Since the rubber cylinder 12 is in contact with the well wall and provides sufficient friction, the pipe string is lifted up with a certain load at this time, the unsealing shear pin 2 is cut off, the reversing outer cylinder 3, the rubber cylinder assembly and the lower floating ring 14 remain in place, the center pipe 18 moves upward relative to the three, the pressure relief groove 15 is sealed by the lower floating ring 14, and the liquid in the rubber cylinder 12 flows to the outside through the groove, realizing pressure relief and unsealing. The pipe string can be recovered by continuing to lift up.

[0033] It is understood that the present invention is described by way of certain embodiments, and those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. Furthermore, under the guidance of the present invention, these features and embodiments may be modified to suit specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are intended to be protected by the present invention.

Claims

1. An open hole packer for leak detection and plugging, characterized by: The invention comprises an upper joint (1), the lower part of the upper joint (1) is connected to a center tube (18) by a thread, the outer surface of the upper joint (1) is connected to a reversing outer tube (3) by an unsealing shear pin (2), a rubber tube assembly is sleeved on the center tube (18), the upper joint (1) is connected to a closing piston (7) by a closing shear pin (6), the center tube (18) is fixedly connected to a liquid injection piston (10) by a starting shear pin (9), a plurality of pressure relief grooves (15) are provided on the outer surface of the lower part of the center tube (18), the rubber tube assembly is connected to a lower floating ring (14) by a thread, and one end of the center tube (18) is connected to a lower joint (16) by a thread.

2. The open hole packer for leak detection and plugging according to claim 1, characterized in that: The upper portion of the upper joint (1) is provided with a thread.

3. The open hole packer for leak detection and plugging according to claim 1, characterized in that: The upper joint (1) is provided with a guide pin (5), the reversing outer cylinder (3) is provided with an L-shaped reversing groove (4), and the guide pin (5) is slidably connected to the reversing groove (4).

4. The open hole packer for leak detection and plugging according to claim 1, characterized in that: Shear nail holes are evenly arranged on the upper portion of the reversing outer cylinder (3), and shear nail grooves corresponding to the shear nail holes are provided on the upper joint (1).

5. The open hole packer for leak detection and plugging according to claim 1, characterized in that: Two groups of pressure transmission holes are axially arranged on the upper part of the central tube (18).

6. The open hole packer for leak detection and plugging according to claim 1, characterized in that: An anti-retraction retaining spring (8) is provided inside the closing piston (7).

7. The open hole packer for leak detection and plugging according to claim 1, characterized in that: The rubber cylinder assembly is composed of an upper rubber cylinder gauge ring (11), a lower rubber cylinder gauge ring (13) and a rubber cylinder (12), wherein the upper rubber cylinder gauge ring (11) and the lower rubber cylinder gauge ring (13) are located at both ends of the rubber cylinder (12), the upper rubber cylinder gauge ring (11) is connected to the reversing outer cylinder (3), and the lower rubber cylinder gauge ring (13) is threadedly connected to the lower floating ring (14).

8. The open hole packer for leak detection and plugging according to claim 1, characterized in that: A sealing ring (17) is provided on the inner side of the lower floating ring (14), and the sealing ring (17) is sleeved on the outer side of the central tube (18).

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