Releasing structure for bridge plug

Abstract

The utility model relates to the technical field of oil and gas well exploitation equipment, in particular to a releasing structure for a bridge plug, which comprises a pull rod, a lower push ring, a fastening nail and a pull rod sealing ring, the lower end of the pull rod is in threaded connection with the lower push ring; the lower push ring is fixed on the bridge plug; the fastening nail is connected with the bottom of the pull rod and attached to the bottom of the lower push ring. The pull rod is sleeved with the inner side of the pull rod sealing ring, and the outer side of the pull rod sealing ring is attached to the lower push ring. Effective sealing is formed between the pull rod and the lower push ring through the pull rod sealing ring, and liquid in a well is prevented from intruding into the lower push ring along the upper portion of the lower push ring. The lower push ring sealing ring further prevents liquid from invading from the lower portion of the lower push ring. Due to the double sealing guarantee, the internal thread of the lower push ring is isolated from corrosive well liquid in the whole downhole operation process, thread damage caused by corrosion is avoided, and therefore the stability and reliability of setting force in the transmission process are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of oil and gas well mining equipment, in particular to a releasing structure for a bridge plug. Background Art

[0002] A bridge plug is a commonly used downhole tool in oil and gas well production. It is a packer that remains at a certain depth in the wellbore and is detached from the tubing string. It is also known as a drop-out packer. The basic operating principle of a bridge plug is to transport it to a predetermined location in the wellbore via a cable. The cable transmits power and an ignition device activates the setting tool, which generates thrust to anchor the bridge plug, set it, and then break through a mechanical weakness, separating the setting tool from the bridge plug and achieving drop-out release.

[0003] Some existing technologies use a soluble metal threaded connection to the tie rod, allowing the release operation to be achieved by pulling the thread apart. However, this structure poses the problem of corrosion on the internal threads of the soluble component. In the harsh environment of oil and gas wells, the well fluid contains various corrosive components. When the internal threads of the soluble component come into contact with the well fluid, a chemical reaction occurs, leading to corrosion of the internal threads.

[0004] Corrosion of the internal threads reduces the setting force. The tightness of the threaded connection is crucial for transmitting the setting force during the setting process. Corrosion of the internal threads reduces the connection strength between the tie rod and other components, thus affecting the setting effect and failing to meet the reliability requirements of bridge plug setting in oil and gas well operations.

[0005] Therefore, it is necessary to design a new type of release structure for the bridge plug to improve the stability and reliability of the bridge plug during the setting process. Utility Model Content

[0006] The utility model aims to provide a release structure for a bridge plug, thereby improving the stability and reliability of the bridge plug during the setting process, thereby solving the technical problems in the background technology.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solution: a release structure for a bridge plug, comprising a pull rod, a push ring, a fastening pin and a pull rod sealing ring, wherein:

[0008] The upper end of the pull rod is connected to the setting tool of the bridge plug; the lower end of the pull rod is threadedly connected to the lower push ring; the lower push ring is fixed on the bridge plug; the fastening nail is connected to the bottom of the pull rod, and the fastening nail is attached to the bottom of the lower push ring;

[0009] The inner side of the pull rod sealing ring is sleeved on the pull rod, and the outer side of the pull rod sealing ring is in contact with the lower push ring.

[0010] Furthermore, a sealing groove is provided on the pull rod, and the sealing groove is an annular groove for installing a pull rod sealing ring;

[0011] The lower portion of the sealing groove of the pull rod is provided with an external thread, and correspondingly, the lower push ring has an internal thread matching the external thread of the pull rod, and the pull rod is threadedly connected to the lower push ring through the external thread;

[0012] The upper part of the internal thread of the push-down ring is provided with a countersunk section which is sealed with the tie rod sealing ring;

[0013] The tie rod sealing ring is installed in the sealing groove of the tie rod and is sealed with the countersunk section of the push-down ring to prevent the liquid in the well from entering the interior of the push-down ring.

[0014] Furthermore, the bottom of the pull rod is provided with an internal thread matching the fastening nail; one end of the fastening nail is provided with an external thread matching the internal thread of the pull rod, and the other end is a nail cap, and the lower end of the lower push ring is provided with an inner annular groove for placing the lower push ring sealing ring; the lower push ring sealing ring is installed in the inner annular groove of the lower push ring, and when the fastening nail is screwed into the internal thread of the pull rod, the nail cap contacts the lower push ring sealing ring to form a seal.

[0015] Furthermore, the fastening pin and the push-down ring are made of soluble alloy material; the pull rod is made of alloy steel.

[0016] Furthermore, the pull rod sealing ring and the push-down ring sealing ring are both rubber sealing rings with circular cross-sections.

[0017] Beneficial effects

[0018] The utility model constructs a strict sealing system by arranging sealing rings at key positions. When the pull rod is connected to the push ring, the pull rod sealing ring forms an effective seal between the sealing groove and the countersunk section, preventing the liquid in the well from invading the interior of the push ring along the upper part of the push ring. The push ring sealing ring further prevents liquid from entering from below the push ring at the inner annular groove at the lower end. This double sealing protection isolates the internal threads of the push ring from corrosive well fluids during the entire downhole operation process, avoids thread damage caused by corrosion, ensures the integrity and strength of the threaded connection, and thus ensures the stability and reliability of the sealing force during transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0020] Figure 1 This is a structural diagram of the hand-dropping structure disclosed in the utility model;

[0021] Figure 2It is a structural diagram of the push-down ring of the hand-releasing structure disclosed in the utility model.

[0022] In the picture:

[0023] 1. Pull rod; 2. Push ring; 3. Fastening pin; 4. Pull rod sealing ring; 5. Push ring sealing ring; 6. Countersunk section; 7. Inner annular groove. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] This utility model aims to address the existing issues with shear pin or threaded connection bridge plug release mechanisms, which can lead to unstable setting forces, impacting setting effectiveness, or even failure to release. By innovatively designing a new release mechanism, the bridge plug's stability and reliability during setting are improved, ensuring smooth release, minimizing downhole accidents, and enhancing the overall efficiency and safety of oil and gas well operations.

[0026] In order to achieve the above purpose, the present invention provides the following technical solutions: Figure 1-2 As shown, a release structure for a bridge plug includes a pull rod 1, a push ring 2, a fastening pin 3 and a pull rod sealing ring 4, wherein:

[0027] The upper end of the tie rod 1 is connected to the setting tool; the lower end of the tie rod 1 is threadedly connected to the lower push ring 2; the lower push ring 2 is fixed on the bridge plug; the fastening nail 3 is connected to the bottom of the tie rod 1, and the fastening nail 3 is attached to the bottom of the lower push ring 2;

[0028] The inner side of the tie rod sealing ring 4 is sleeved on the tie rod 1, and the outer side of the tie rod sealing ring 4 is in contact with the lower push ring 2;

[0029] The pull rod sealing ring 4 is used to create a seal between the pull rod 1 and the lower push ring 2; the fastening nail 3 is attached to the bottom of the lower push ring 2 to form a seal on the bottom of the lower push ring 2; thereby isolating the internal thread on the lower push ring 2 from the outside world and protecting the internal thread.

[0030] Furthermore, a sealing groove is provided at the lower end of the tie rod 1, and the sealing groove is used to install the tie rod sealing ring 4 to prevent the liquid in the well from entering the threaded connection part; the sealing groove is an annular groove, and its depth and width are adapted to the size of the tie rod sealing ring 4;

[0031] The lower end of the sealing groove of the pull rod 1 is provided with an external thread, and the corresponding lower push ring 2 has an internal thread matching the external thread of the pull rod 1. The pull rod 1 is threadedly connected to the lower push ring 2 through the external thread to transmit the pulling force;

[0032] The upper end of the lower push ring 2 is provided with a countersunk section 6 that seals with the tie rod sealing ring 4. The lower push ring 2 is connected to the tie rod 1 through an internal thread to jointly transmit the sealing force. The countersunk section 6 provides a sealing space for the tie rod sealing ring 4. The countersunk section 6 is a cylindrical groove with an inner diameter slightly larger than the outer diameter of the tie rod 1. Its depth is sufficient to accommodate the tie rod sealing ring 4 and ensure that the sealing ring can effectively seal when under pressure.

[0033] The tie rod sealing ring 4 is installed in the sealing groove of the tie rod 1 and is sealed with the countersunk section 6 of the lower push ring 2 to prevent the liquid in the well from entering the lower push ring 2.

[0034] Furthermore, the bottom of the pull rod 1 is provided with an M8 internal thread matching the fastening nail 3, and the M8 internal thread is used to install the fastening nail 3 to prevent the connection from loosening;

[0035] One end of the fastening nail 3 is provided with an external thread matching the M8 internal thread of the pull rod 1, and the other end is a nail cap. The fastening nail 3 is screwed into the M8 internal thread of the pull rod 1, and the nail cap contacts the lower push ring sealing ring 5 to form a seal. When the fastening nail 3 is tightened, the pre-tightening force of the thread between the pull rod 1 and the lower push ring 2 can be increased to prevent the pull rod 1 and the lower push ring 2 from loosening, and the sealing effect between the nail cap and the lower push ring sealing ring 5 can also be enhanced;

[0036] An inner annular groove 7 for placing the lower push ring sealing ring 5 is provided at the lower end of the lower push ring 2 , and the width and depth of the inner annular groove 7 are designed according to the size of the lower push ring sealing ring 5 .

[0037] The lower push ring sealing ring 5 is installed in the inner annular groove 7 of the lower push ring 2, forming a sealing interface with the lower push ring 2 and the upper surface of the fastening nail 3 to prevent the liquid in the well from entering the internal threaded area from the lower end of the lower push ring 2.

[0038] Furthermore, the fastening pin 3 and the lower push ring 2 are made of a soluble alloy material; the soluble alloy material can dissolve under certain conditions, facilitating subsequent downhole operations. The pull rod 1 is made of alloy steel, which has high strength and toughness and can withstand large tensile forces. It should be noted that since the lower push ring 2 is made of a soluble alloy material, the strength of the soluble alloy material is lower than that of the alloy steel used to make the pull rod 1. This makes it easier for the setting tool to pull off the internal thread on the lower push ring 2 through the pull rod 1 when pulling the pull rod 1 to break it.

[0039] Furthermore, the rod sealing ring 4 is a circular cross-section rubber sealing ring, the diameter of which is slightly larger than the inner diameter of the sealing groove of the rod 1, and is made of a high-temperature resistant, corrosion-resistant, and aging-resistant rubber material, such as fluororubber.

[0040] Furthermore, the lower push ring sealing ring 5 is a rubber sealing ring with a circular cross-section, the diameter of which is slightly larger than the size of the annular groove 7 in the lower push ring 2, and the material is the same as that of the pull rod sealing ring 4.

[0041] The setting tool drives the pull rod 1 and the lower push ring 2 to apply the bridge plug setting thrust to the bridge plug, so that the bridge plug is anchored and set in sequence. When the anchoring and setting work are completed, the setting tool continues to pull the pull rod 1, and finally breaks the mechanical weakness, that is, the pull rod 1 pulls off the internal thread on the lower push ring 2, so that the setting tool is separated from the bridge plug, and the bridge plug is separated.

[0042] The working principle and process are as follows:

[0043] During oil and gas well operations, the assembled bridge plug release structure is first connected to other bridge plug components (such as the setting tool, anchoring device, etc.) to form a complete bridge plug system, which is then lowered to the predetermined position in the wellbore via a cable or other means of transportation. After reaching the predetermined position, the setting tool is activated by power transmission via the cable, and the thrust generated by the setting tool acts on the bridge plug system. During the setting process, the setting force is transmitted to the push ring 2 through the pull rod 1.

[0044] At this point, the tie rod seal 4 forms an effective seal between the tie rod 1 and the lower push ring 2, preventing wellbore fluid from invading the lower push ring 2 from its upper portion. The lower push ring seal 5, located in the inner annular groove 7, further prevents fluid from entering from below. This dual sealing ensures that the internal threads of the lower push ring 2 are isolated from corrosive wellbore fluids throughout downhole operations, preventing thread damage due to corrosion.

[0045] Because the internal threads are well protected, the threaded connection between the tie rod 1 and the lower push ring 2 always maintains a tight fit. During the setting operation, the setting force is accurately and stably transmitted from the tie rod 1 to the lower push ring 2 and the entire bridge plug system, allowing the bridge plug to be securely anchored to the wellbore wall and preventing problems such as sliding, shifting, or sealing failure caused by unstable setting force.

[0046] The setting tool drives the pull rod 1 and the lower push ring 2 to apply the bridge plug setting thrust to the bridge plug, so that the bridge plug is anchored and set in sequence. When the anchoring and setting work are completed, the setting tool continues to pull the pull rod 1, and finally breaks the mechanical weakness, that is, the pull rod 1 pulls off the internal thread on the lower push ring 2, so that the setting tool is separated from the bridge plug, and the bridge plug is separated.

[0047] The bridge plug remains independently within the well to perform its functions of plugging and isolating. During subsequent operations, the push ring 2 and fastener 3, made of soluble alloy material, gradually dissolve according to the wellbore environmental conditions. If the bridge plug needs to be recovered or other interventions are required, the dissolved components will not hinder the operation, reducing the difficulty and cost of the operation.

[0048] The embodiments of the present invention are provided for purposes of illustration and description and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those skilled in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention and to enable those skilled in the art to understand the present invention and design various embodiments with various modifications suitable for specific applications.

Claims

1. A release structure for a bridge plug, characterized in that: It comprises a pull rod (1), a push ring (2), a fastening nail (3) and a pull rod sealing ring (4), wherein: The upper end of the pull rod (1) is connected to the setting tool of the bridge plug; the lower end of the pull rod (1) is threadedly connected to the lower push ring (2); the lower push ring (2) is fixed on the bridge plug; the fastening nail (3) is connected to the bottom of the pull rod (1), and the fastening nail (3) is attached to the bottom of the lower push ring (2); The inner side of the pull rod sealing ring (4) is sleeved on the pull rod (1), and the outer side of the pull rod sealing ring (4) is in contact with the lower push ring (2).

2. The release structure for a bridge plug according to claim 1, characterized in that: The pull rod (1) is provided with a sealing groove, which is an annular groove and is used to install a pull rod sealing ring (4); The lower portion of the sealing groove of the pull rod (1) is provided with an external thread, and correspondingly, the lower push ring (2) has an internal thread matching the external thread of the pull rod (1), and the pull rod (1) is threadedly connected to the lower push ring (2) via the external thread; The upper portion of the internal thread of the lower push ring (2) is provided with a countersunk section (6) that seals with the tie rod sealing ring (4); The tie rod sealing ring (4) is installed in the sealing groove of the tie rod (1) and is sealed with the countersunk section (6) of the lower push ring (2) to prevent the liquid in the well from entering the interior of the lower push ring (2).

3. The release structure for a bridge plug according to claim 1, characterized in that: The bottom of the pull rod (1) is provided with an internal thread matching the fastening nail (3); one end of the fastening nail (3) is provided with an external thread matching the internal thread of the pull rod (1), and the other end is a nail cap, and the lower end of the lower push ring (2) is provided with an inner annular groove (7) for placing the lower push ring sealing ring (5); the lower push ring sealing ring (5) is installed in the inner annular groove (7) of the lower push ring (2), and when the fastening nail (3) is screwed into the internal thread of the pull rod (1), the nail cap contacts the lower push ring sealing ring (5) to form a seal.

4. The release structure for a bridge plug according to claim 1, characterized in that: The fastening nail (3) and the lower push ring (2) are made of soluble alloy material; the pull rod (1) is made of alloy steel.

5. The release structure for a bridge plug according to claim 1, characterized in that: The pull rod sealing ring (4) and the push-down ring sealing ring (5) are both rubber sealing rings with circular cross-sections.

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