Packer

Abstract

The present invention proposes a packer, which includes a cylindrical main body and a packer assembly sleeved on the outer wall of the main body, wherein the packer assembly has an elastic packer and an actuating device located radially inward of the elastic packer, the actuating device can dispersedly apply force to the elastic packer so that the elastic packer is decomposed and deformed to perform adaptive sealing. During use, the packer has the characteristic of being able to adapt to expansion according to an irregular open hole wellbore to solve the problem of poor sealing of the open hole packer.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas field production devices, and in particular to a packer, which is especially suitable for open hole packing. Background Art

[0002] Open hole completion is a completion method in which cementing is performed down to the top of the production layer, leaving the production layer exposed. Its advantages are a large exposed area of ​​the production layer and low resistance to oil and gas flowing into the well. Combined with open hole staged fracturing, it can achieve higher production capacity for the gas well.

[0003] In the implementation of this completion method, open hole packers are often used. At present, commonly used open hole packers include expandable open hole packers, oil-expandable open hole packers, etc. But no matter which type of packer, the open hole section is required to be as flat and smooth as possible, with high roundness. Only in this way can the rubber be guaranteed to be in close contact with the open hole rock wall after uniform expansion, and the contact force between the rubber and the rock wall at each point remains relatively consistent, meeting the requirements of sealing and pressure bearing. Once the wellbore is irregular, with low radial roundness or inconsistent axial diameters, there will be a "bridging" phenomenon in which the rubber has been pressed tightly in some parts and has not been in contact with the rock wall in some parts, which will lead to poor sealing of the open hole packer or insufficient sealing force, resulting in failure of the packer. It is precisely because of this that open hole completion technology has not been promoted in major oil and gas fields.

[0004] Therefore, it is necessary to invent a packer to solve the problem of packer sealing failure caused by the irregularity of the open hole wall. Summary of the invention

[0005] In view of some or all of the above technical problems existing in the prior art, the present invention proposes a packer which has the characteristic of being able to adapt to the expansion according to the irregular open hole wellbore to solve the problem of loose sealing of the open hole packer.

[0006] According to the present invention, a packer is provided, comprising a cylindrical main body and a packer assembly sleeved on the outer wall of the main body, wherein the packer assembly has:

[0007] Elastic seals,

[0008] The actuating device is located radially inward of the elastic sealing member, and the actuating device can disperse the force on the elastic sealing member so that the elastic sealing member is decomposed and deformed to perform adaptive sealing.

[0009] In one embodiment, the actuating means comprises:

[0010] A support tube is sleeved on the outer wall of the main body and located on the inner side of the elastic sealing member.

[0011] A plurality of actuating members are arranged on the support tube, and the actuating members are configured to move radially relative to the support tube under the action of force and to apply a force to the elastic sealing member in a top-extending manner to actuate the elastic sealing member to deform.

[0012] In one embodiment, a radial through hole is configured on the support tube, and the actuating member is configured as a push rod and is inserted into the through hole. When the push rod is subjected to radial force, it can move radially outward along the through hole to push out the elastic sealing member.

[0013] In one embodiment, a push-out head is provided at the outer end of the outer wall of the push-out rod extending out of the through hole, and friction lines are provided on the outer end wall of the push-out head.

[0014] In one embodiment, a ratchet structure for preventing the extending rod from retreating is provided between the outer peripheral wall of the extending rod and the inner wall of the through hole.

[0015] In one embodiment, a ball seat for sealing the inner cavity of the body is provided in the inner cavity of the lower end of the body, the through hole is configured to communicate with the inner cavity of the body, and a movable seal is provided between the extension rod and the through hole.

[0016] In one embodiment, a connecting hole for connecting the through hole and the inner cavity of the body is provided on the peripheral wall of the body, and the cross-sectional area of ​​the connecting hole is smaller than the cross-sectional area of ​​the through hole.

[0017] In one embodiment, a radially extending blind hole is provided at the inner end of the extension rod, and the position of the blind hole matches the corresponding connecting hole.

[0018] In one embodiment, a circumferential groove is provided on the outer wall of the body, wherein the sealing assembly is embedded in the groove, and the axial ends of the elastic sealing member are sealed and fixedly connected to the wall of the groove.

[0019] In one embodiment, the actuators uniformly distributed in the circumferential direction form a group, and multiple groups of actuators are arranged in the axial direction, wherein the actuators between adjacent groups in the axial direction are distributed in a plum blossom pattern, and / or the actuators located at both ends of the axial direction are denser than the actuators located in the middle.

[0020] Compared with the prior art, the advantage of the present invention is that during use, the packer has the characteristic of being able to adapt to expansion according to the irregular open hole wellbore, so as to solve the problem of loose sealing of the open hole packer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, in which:

[0022] Figure 1 shows a packer according to one embodiment of the present invention;

[0023] Figure 2 For Figure 1 AA section view;

[0024] Figure 3 An enlarged view of an actuating device according to one embodiment of the present invention is shown.

[0025] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION

[0026] The present invention will be further described below in conjunction with the accompanying drawings.

[0027] Figure 1 A packer according to the present invention is shown. Figure 1 As shown, the packer 100 includes a main body 1 and a packing assembly 2. The main body 1 is cylindrical and mainly serves as a connection and support. The packing assembly 2 is sleeved on the outer wall of the main body 1 and mainly serves as a packing. In addition, the packing assembly 2 has an elastic packing member 21 and an actuating device 22. The elastic packing member 21 can be elastically deformed and is used to abut against the wall of the open hole to be packed when it is necessary to seal, so as to play a sealing role. The actuating device 22 is located radially inside the elastic packing member 21. According to the actuating device 22 of the present application, a dispersed force can be applied to the elastic packing member 21, so that the elastic packing member 21 is decomposed and deformed to perform adaptive sealing. Therefore, in the packer 100 of the present application, the elastic packing member 21 avoids the overall deformation of the elastic packing member in the prior art, but can adapt to the characteristics of the open hole wall such as its own smoothness and perform dispersed deformation, thereby achieving a better sealing effect. It is this characteristic of the packer 100 that makes it particularly suitable for open hole wells, but the present application does not limit its scope of use, that is, the packer 100 can also be used in cased wellbores that need to be isolated.

[0028] In one embodiment, the actuating device 22 includes a support tube 221 and an actuating member 222. The support tube 221 is sleeved on the outer wall of the main body 1 and is located on the inner side of the elastic sealing member 21, mainly playing a supporting role. The actuating member 222 is arranged on the support tube 221. The actuating member 222 is configured to be able to move radially relative to the support tube 221 under the action of force, and to apply a top-extending force to the elastic sealing member 21 and actuate the elastic sealing member 21 to deform, thereby playing a sealing role.

[0029] In a specific embodiment, the support cylinder 221 is configured with a radial through hole 223, such as Figure 2 , as shown in FIG3 . The actuating member 222 is configured as a push rod and is inserted into the through hole 223 . When the push rod is subjected to radial force, it can move radially outward along the through hole 223 to push the elastic sealing member 21 .

[0030] Preferably, a top extension head 224 is provided at the outer end of the top extension rod extending out of the outer wall of the through hole 223. In the initial state, the top extension head 224 protrudes from the inner cavity of the through hole 223 to ensure that the top extension rod can move better in the through hole 223. At the same time, the cross-sectional area of ​​the top extension head 224 becomes relatively larger, so the top extension area can be appropriately increased to ensure the top extension strength. Preferably, friction lines are provided on the outer end wall of the top extension head 224. This arrangement can increase the friction strength between the top extension head 224 and the elastic sealing member 21, and ensure the top extension firmness and stability.

[0031] In addition, a ratchet structure 225 for preventing the extension rod from retreating is provided between the outer peripheral wall of the extension rod and the inner wall of the through hole 223. The ratchet structure 225 can allow the extension rod to move radially outward relative to the through hole 223, and can also prevent the extension rod from retreating, thereby ensuring the sealing effect and reliability.

[0032] In one embodiment, a ball seat 11 is provided in the inner cavity of the lower end of the body 1 for blocking the inner cavity of the body 1. That is, after the ball 3 is put into the inner cavity of the body 1, the inner cavity of the body 1 is blocked, so that the packer 100 can be set by pumping fracturing fluid. The through hole 223 is configured to communicate with the inner cavity of the body 1, and a movable seal 226 is provided between the extension rod and the through hole 223. When the pressure fluid is pumped into the inner cavity of the body 1, the pressure fluid can act on the radial inner end of the extension rod, thereby actuating the extension rod to move radially outward relative to the through hole 223.

[0033] In order to ensure the communication effect of the pressure liquid, a communication hole 12 for connecting the through hole 223 and the inner cavity of the body 1 is provided on the wall of the body 1. That is, the communication hole 12 is a radial hole provided on the body 1 in a position matching the through hole 223. Preferably, the cross-sectional area of ​​the communication hole 12 is smaller than the cross-sectional area of ​​the through hole 223. This arrangement can ensure that a throttling pressure difference is generated between the two, so that a greater force acts on the radial inner end of the extension rod to better promote its radial movement.

[0034] Preferably, a radially extending blind hole 227 is provided at the inner end of the extension rod. The blind hole 227 matches the position of the corresponding connecting hole 12. With this arrangement, most of the liquid flowing from the connecting hole 12 to the through hole 223 enters the blind hole 227. On the one hand, this method can effectively prevent the liquid from entering between the extension rod and the inner wall of the through hole 223, so that the sealing pressure of the moving seal 226 is relatively small; on the other hand, this method can ensure that the pressure liquid acts better on the extension rod, thereby ensuring the extension effect.

[0035] Structurally, a circumferential groove 13 is provided on the outer wall of the main body 1. The sealing assembly 2 is embedded in the groove 13. The elastic sealing member 21 can be constructed as a rubber sleeve made of rubber material. And the axial ends of the elastic sealing member 21 are sealed and fixedly connected to the wall of the groove 13. This arrangement of the groove 13 can well protect the sealing assembly 2 therein, and has a simple structure. In the initial state, the sealing assembly 2 is completely embedded in the groove 13 so that its outer wall does not protrude from the outer wall of the main body 1, thereby ensuring the smooth lowering of the sealing device 100 and preventing the sealing elastic member 21 from being scratched and damaged. Preferably, the elastic deformation amount of the elastic sealing member 21 that can reliably withstand pressure is greater than the footage difference of the ratchet structure 225, so as to ensure the reliability of the sealing of the elastic sealing member 21 after the internal pressure is unloaded and the ratchet structure 225 retreats slightly.

[0036] In order to ensure the sealing effect, the actuators 222 evenly distributed in the circumferential direction are grouped together. Multiple groups of actuators 222 are arranged in the axial direction. Among them, the actuators 222 between adjacent groups in the axial direction are distributed in a plum blossom pattern. The actuators 222 located at both ends of the axial direction are more densely distributed than the actuators 222 located in the middle. This arrangement can make the elastic sealing members 21 at both ends have a more decentralized deformation trend, which can ensure the sealing effect.

[0037] The packer 100 further includes an upper joint 5 and a lower joint 6. The upper joint 5 is arranged at the upper end of the body 1. The lower joint 6 is arranged at the lower end of the body 1. The upper joint 5 and the lower joint 6 both play a connecting role and are used to set the packer 100 on the pipe string.

[0038] According to the following Figures 1 to 3 The method of using the packer 100 is described in detail.

[0039] The packer 100 is set on a pipe string and lowered into the wellbore.

[0040] When sealing is required, a ball 3 is first thrown into the pipe string. The ball 3 is seated at the ball seat 11 to seal the inner cavity of the main body 1.

[0041] Then, pressure liquid is pumped into the pipe string, and the pressure is held in the inner cavity of the main body 1. The pressure liquid flows to the through hole 223 through the connecting hole 12, and most of it acts on the blind hole 227. Under the action of pressure, the extension rod moves radially in the inner cavity of the through hole 223 to extend the elastic packing 21. During the extension process, the wall of the wellbore outside the elastic packing 21 may not be smooth, but through the dispersed force of multiple extension rods, the elastic packing 21 is deformed in a decomposed manner and better adapted to the wall of the wellbore. In other words, according to the height of the wall of the wellbore, the extension rod can be adaptively extended to different lengths, so that the deformation of different parts of the elastic packing 21 can be different, thereby achieving a good sealing effect everywhere, and then the overall sealing effect of the packer meets the use requirements.

[0042] In the present application, the directional terms "upper" and "lower" are all referred to the stratum when the packer 100 is working.

[0043] The above are only preferred embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily make changes or modifications within the technical scope disclosed in the present invention, and such changes or modifications should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A packer, characterized in that: The invention comprises a cylindrical main body and a packing assembly sleeved on the outer wall of the main body, wherein the packing assembly has: Elastic seals, An actuating device is located radially inside the elastic sealing member, and the actuating device can disperse the force on the elastic sealing member, so that the elastic sealing member is decomposed and deformed to perform adaptive sealing. The actuating device comprises a support tube sleeved on the outer wall of the main body and located on the inner side of the elastic sealing member, and a plurality of actuating members arranged on the support tube, wherein the actuating members are configured to be able to move radially relative to the support tube under the action of force and to extend and apply force to the elastic sealing member to actuate the elastic sealing member to deform. The support tube is provided with a radial through hole, the actuating member is configured as a push rod and is inserted into the through hole. When the push rod is subjected to a radial force, it can move radially outward along the through hole to push out the elastic sealing member. A ball seat for blocking the inner cavity of the main body is provided in the inner cavity of the lower end of the main body, and the through hole is configured to communicate with the inner cavity of the main body. A connecting hole for connecting the through hole and the inner cavity of the main body is provided on the peripheral wall of the main body, and the cross-sectional area of ​​the connecting hole is smaller than the cross-sectional area of ​​the through hole. A radially extending blind hole is provided at the inner end of the extension rod, and the blind hole matches the corresponding connecting hole position. The actuating members uniformly distributed in the circumferential direction form one group, and multiple groups of the actuating members are arranged in the axial direction, and the actuating members located at both ends of the axial direction are more densely distributed than the actuating members located in the middle.

2. The packer according to claim 1, characterized in that: A jacking head is arranged at the outer end of the jacking rod extending out of the outer wall of the through hole, and friction lines are arranged on the outer end wall of the jacking head.

3. The packer according to claim 1 or 2, characterized in that: A ratchet structure for preventing the extending rod from retreating is arranged between the outer peripheral wall of the extending rod and the inner wall of the through hole.

4. The packer according to claim 1 or 2, characterized in that: A movable sealing member is arranged between the extending rod and the through hole.

5. The packer according to claim 1 or 2, characterized in that: A circumferential groove is arranged on the outer wall of the main body, wherein the sealing assembly is embedded in the groove, and the axial ends of the elastic sealing member are sealed and fixedly connected to the wall of the groove.

6. The packer according to claim 1 or 2, characterized in that: The actuating members between adjacent groups in the axial direction are distributed in a quincuncial pattern.

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