CN217151862U - Telescopic short piece and underground pipe column - Google Patents

Abstract

The embodiment of the application relates to the technical field of petroleum and natural gas drilling, and discloses a telescopic short section and a downhole tubular column, which comprises a central tube, an intermediate connecting sleeve and a piston sleeve, wherein the central tube is of an internal hollow structure, the intermediate connecting sleeve and the piston sleeve are respectively sleeved on the central tube, and the telescopic short section adopts a hydraulic opening mode to realize the functions of opening and gradually unsealing each layer of section packer by layer control, so that the whole downhole tubular column is retrieved, and the operation timeliness and the operation cost are reduced.

Description

Telescopic short piece and underground pipe column

Technical Field

The embodiment of the utility model provides a relate to oil, natural gas drilling technical field, concretely relates to flexible nipple joint and tubular column in pit.

Background

At present, after the offshore oil and gas field lower part multilayer sand control and layered water injection pipe column are operated for a long time, the whole pipe column needs to be lifted up for the deblocking of the top packer at the uppermost end of the pipe column, and the central shaft of the packer and an anchoring mechanism generate relative displacement, so that the packer is deblocked.

The inventor of this application discovers in the research, because of whole tubular column exists a plurality of isolation packers, in addition the dead weight of tubular column and rubs and hinder, whole trip of going up of tubular column can't go on because of well head hoisting device's ability is not enough, has caused the unable deblocking of top packer and the unable problem of playing of whole sand control tubular column.

SUMMERY OF THE UTILITY MODEL

In view of the above problem, the embodiment of the utility model provides a flexible nipple joint and tubular column in pit for solve the above-mentioned problem that exists among the prior art.

According to the utility model discloses an aspect provides a flexible nipple joint, include: the outer cylinder, the central pipe, the middle connecting sleeve and the piston sleeve; the outer cylinder is of an internal hollow structure, one end of the outer cylinder is connected with the middle connecting sleeve and sleeved on the central pipe, and the other end of the outer cylinder is connected with the upper connecting joint; the central tube is of an internal hollow structure, one end of the central tube is connected with the outer barrel and is in butt joint with the upper connecting joint, the other end of the central tube is in butt joint with the lower connecting joint, and the middle connecting sleeve and the piston sleeve are respectively sleeved on the central tube; the outer wall of the central pipe is provided with a first convex part and a first groove, and the first convex part is positioned at one end, far away from the middle connecting sleeve, of the outer wall of the central pipe; one end of the middle connecting sleeve is fixedly connected with the outer cylinder, one end of the middle connecting sleeve, which is close to the piston sleeve, extends to form a fixed cylinder, a second convex part is arranged on the inner side of one end of the fixed cylinder, and the second convex part is arranged in the first groove; the inner side of the piston sleeve is provided with a piston part, a pressing part and a releasing part, and the piston part is positioned at one end of the inner side of the piston sleeve, which is far away from the middle connecting sleeve, and is abutted against the first convex part; the pressing part is positioned between the piston part and the releasing part and is used for pressing the second convex part of the fixed cylinder in the first groove; one end of the release part is connected with the middle connecting sleeve through a connecting part; a pressure transmission hole is formed in the central pipe at the position where the first convex part is abutted to the piston part in a penetrating manner; when to in the center tube applys pressure, pressure passes through pass the pressure hole to piston portion transmission makes piston portion is keeping away from bear first pressure in the direction of adapter sleeve, works as when first pressure value is greater than and predetermines the threshold value, release portion one end with the adapter sleeve separation, piston portion drives piston sleeve is to keeping away from the direction of adapter sleeve removes, compress tightly the portion with the separation of second convex part, the second convex part is followed throw off in the first recess, release portion with form the cavity between the center tube outer wall, the solid fixed cylinder is in freely sliding in the cavity, make the urceolus with the center tube relative slip.

The technical scheme that this application embodiment provided, through setting up biography pressure hole, sealed rubber ring and piston sleeve 3, make flexible nipple joint possess the function that pressure control opened, can be more convenient when making borehole operation control flexible nipple joint. Wherein, the starting threshold value of pressure can be adjusted through the joint strength of adjustment connecting portion according to actual conditions, has improved the suitability of flexible nipple joint.

In an optional mode, a guide groove is formed in the position, corresponding to the intermediate connecting sleeve, on the outer wall of the central pipe in the axial direction, a guide portion is arranged on the inner surface of the intermediate connecting sleeve, the guide portion is arranged in the guide groove, and the intermediate connecting sleeve moves along the guide groove. When the torque needs to be transmitted to the pipe column in the process of recovering the pipe column, the guide groove and the guide part have a limiting effect on the rotation of the central pipe and the middle connecting sleeve, so that the telescopic short section can transmit the torque to the lower pipe column through the guide groove and the guide part. Simultaneously, the guide way with the guide part can also improve the stability of intermediate junction cover when flexible activity.

In an alternative mode, sealing structures are respectively arranged on the outer wall of the central tube at positions on two sides of the pressure transfer hole, and the piston part and the outer wall of the central tube form a closed space through the sealing structures. When needs start stretch shorten the festival, need through to transmission pressure in the center tube makes pressure pass through the biography pressure hole transmits to the piston intracavity promotes thereby the piston bush realizes the start-up of flexible nipple joint the biography pressure hole both sides set up seal structure then can guarantee better that pressure can not reveal after transmitting the piston chamber, guaranteed the operation of piston bush.

In an embodiment of the present application, the sealing structure is a sealing rubber ring. And sealing the piston cavity by using a sealing rubber ring.

In an embodiment of the application, the connection is a shear pin. When pressure is applied to the piston cavity, a certain pressure threshold value is required to be reached to push the piston sleeve, namely, the pressure required for breaking the connection of the connecting part is the pressure threshold value. One end of the release part is connected with the middle connecting sleeve through the shearing pins, and the size of the pressure threshold value can be adjusted by adjusting the number of the shearing pins.

In an alternative mode, one end of the central tube close to the intermediate connecting sleeve is provided with a stopping part, and when the intermediate connecting sleeve moves axially, the stopping part is used for limiting the stroke of the intermediate connecting sleeve. When the telescopic short section successfully realizes the unsealing of the pipe column, the pipe column needs to be lifted and recovered, and the blocking part ensures that the middle connecting sleeve can transmit lifting force to the pipe column below while ensuring a certain movable telescopic space.

In an embodiment of the present application, the stopper is disposed at one end of the center pipe by a thread, and an outer diameter of the stopper is larger than an inner diameter of the intermediate coupling sleeve. When the stopping part abuts against one end of the middle connecting sleeve, the movement of the middle connecting sleeve is limited, and in order to enable the stopping part to abut against the middle connecting sleeve, the outer diameter of the stopping part must be larger than the inner diameter of the middle connecting sleeve.

In an embodiment of the present application, the fixed cylinder includes a plurality of elastic extension portions, each of the elastic extension portions is disposed at an interval in an axial direction of the fixed cylinder, and the second protrusion is disposed at one end of the elastic extension portion. The elastic extension parts are axially arranged on the fixed cylinder at intervals, and the second convex part is arranged at one end of the elastic extension part, so that a spring claw type locking structure is formed at one end of the fixed cylinder and is connected with the central pipe in a multi-point mode, the connection stability is guaranteed, and the fixed cylinder is beneficial to bearing larger axial load.

According to the utility model discloses an on the other hand provides a tubular column in pit, include: the pipe column comprises a pipe column body and the telescopic short section in the embodiment, wherein the telescopic short section is connected with the pipe column body. Through the tubular column body with the tubular column in pit that flexible nipple joint is constituteed can realize tubular column length compensation, layered control and open, the function of deblocking each layer section packer and the recovery of whole tubular column in pit step by step.

In an embodiment of the present application, the column body is a cylindrical structure with a hollow interior. The pipe column body is hollow and is used as a channel for flowing of a downhole fluid medium or tripping of a downhole tool.

The embodiment of the utility model provides a pass through the center tube the intermediate junction cover with the combination of piston sleeve can make flexible nipple joint possesses simple structure, and application scope is wide, but layered control is opened step by step, can transmit the moment of torsion, can bear great axial load, the advantage of unexpected start-up is difficult for appearing.

The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the present invention is given.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

fig. 1 is a plan view showing an overall structure of a telescopic short joint provided by an embodiment of the present invention;

fig. 2 is an enlarged plan view of the main structure of a telescopic short joint provided by the embodiment of the present invention;

fig. 3 is a plan view of a central tube of the telescopic short joint provided by the embodiment of the present invention;

fig. 4 shows a plan view of a middle connection sleeve of the telescopic short joint provided by the embodiment of the present invention;

fig. 5 shows a schematic structural diagram of a fixed cylinder of a telescopic short joint provided by the embodiment of the present invention;

fig. 6 is a plan view of a piston sleeve of a telescopic short joint provided by an embodiment of the present invention;

fig. 7 shows a plan view of the working state of the telescopic short joint provided by the embodiment of the utility model.

The reference numbers in the detailed description are as follows:

1-a central tube;

11-a first convex part, 12-a first concave groove, 13-a pressure transfer hole, 14-a sealing structure, 15-a guide groove and 16-a stopping part;

2-middle connecting sleeve;

21-fixed cylinder, 22-second convex part, 23-guide part, 24-elastic extension part;

3-a piston sleeve;

31-piston part, 32-compression part, 33-release part, 34-connection part;

4-outer cylinder;

5-connecting the joint;

6-lower connecting joint.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are merely used to more clearly illustrate the technical solutions of the present application, and therefore are only examples, and the protection scope of the present application is not limited thereby.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "including" and "having," and any variations thereof, in the description and claims of this application and the description of the above figures are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first", "second", and the like are used only for distinguishing different objects, and are not to be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary-secondary relationship of the technical features indicated. In the description of the embodiments of the present application, "a plurality" means two or more unless specifically defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is only one kind of association relationship describing an associated object, and means that three relationships may exist, for example, a and/or B, and may mean: there are three cases of A, A and B, and B. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural pieces" refers to two or more (including two).

In the description of the embodiments of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", and the like, indicate the directions or positional relationships indicated in the drawings, and are only for convenience of description of the embodiments of the present application and for simplicity of description, but do not indicate or imply that the referred device or element must have a specific direction, be constructed and operated in a specific direction, and thus, should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless otherwise explicitly stated or limited, the terms "mounted," "connected," "fixed," and the like are used in a broad sense, and for example, may be fixedly connected, detachably connected, or integrated; mechanical connection or electrical connection is also possible; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

During operations such as well drilling, well cementation, testing, well completion, water injection, downhole and the like, in order to seal and separate an oil pipe and an oil gas well casing or an open hole well wall annular space, a downhole pipe column is required to be connected with a packer, and when the pipe column is lowered to a designed depth, the packer is pressed and started. Deblocking packer need lift the tubular column and make packer center pin and anchoring mechanism take place relative displacement, because there are a plurality of packers in whole tubular column, including the dead weight of tubular column and the friction of packer and the wall of a well hinder, whole tubular column lift often because of well head hoisting device's ability not enough and can't go on, lead to the unable deblocking of packer and the unable problem of playing of whole tubular column. Currently, field operations can only adopt two solutions: the first mode is a sectional cutting and sectional fishing combined operation mode, and the mode has long operation time, long operation preparation time and large operation difficulty. The other is that increase flexible nipple joint in the tubular column, in order to reduce borehole operation accident probability, how to make the ability of flexible nipple joint bear bigger axial load and guarantee the stability of start-up very important.

The inventor of the application notices that the flexible nipple joint among the prior art adopts mechanical type length compensation mode, and is inefficacy easily when tubular column axial load is great, causes the wriggling of packer, very easily causes packer inefficacy, influences borehole operation, and axial load starts and needs great axial force, is difficult for starting, and goes into or normal operation in-process axial load is whole to be born by cutting off the structure, and bearing capacity is little, starts in advance easily. Therefore, the development of a telescopic short section which can be controlled in a layered mode, can provide the free telescopic length of the tubular column step by step and is simple and stable in structure is urgently needed.

In order to solve the above problems, the inventor has designed a telescopic short section by means of research, pressure is injected into a pipe column by adopting an injection pressure opening mode, the pressure is transmitted into a central pipe in the telescopic short section through the pipe column and is transmitted into a piston part in a piston sleeve through a pressure transmission hole in the central pipe, a piston cavity is formed in the piston part, when the pressure reaches a preset pressure threshold value of the telescopic short section, the connection of a connecting part is disconnected, the piston sleeve axially moves in a direction away from a middle connecting sleeve under the action of the pressure of the piston part, so that a pressing part in the piston sleeve does not press a second convex part on the middle connecting sleeve any more, the second convex part can be separated from a first groove on the central pipe, the middle connecting sleeve is not limited by the central pipe any more, when a lifting force is applied to the upper connecting joint, the upper connecting joint drives an outer cylinder to move the middle connecting sleeve upwards relative to the central pipe, the length compensation of the telescopic short section to the pipe column is realized. Because the connecting part on the telescopic short section does not directly bear the axial pressure, but bears the axial pressure through the second convex part on the middle connecting sleeve, the capability of the telescopic short section for bearing the axial pressure is improved, and the accidental starting in the process of downhole operation is avoided. Due to the fact that the injection pressure opening mode is adopted, when the time-saving opening and shortening mode needs to be opened, only injection pressure needs to be injected into the pipe column, axial load does not need to be additionally provided, and therefore starting difficulty is lowered, and operation timeliness and operation cost are reduced. Meanwhile, due to the fact that the shearing structure capable of adjusting the pressure threshold value according to the number of the shearing connection points is arranged, when the starting sequence of each telescopic short section of the whole tubular column needs to be controlled respectively, the starting sequence can be achieved by increasing or decreasing the number of the shearing connection points, and therefore the effect of starting the tubular column step by step or simultaneously is achieved.

The telescopic short section disclosed by the embodiment of the application can be used for operations such as drilling, well cementation, testing, well completion, water injection, underground and the like, can also be applied to any other scenes needing length compensation, and is only described by taking the operation in the underground as an example in the embodiment of the application.

According to some embodiments of the application, referring to fig. 1 and 2, fig. 1 shows a plan view of the overall structure of the telescopic short joint, and fig. 2 shows an enlarged plan view of the main structure of the telescopic short joint. The application provides a flexible nipple joint. The telescopic short section comprises an outer barrel 4, a central tube 1, a middle connecting sleeve 2 and a piston sleeve 3, wherein the outer barrel 4 is of an internal hollow structure, one end of the outer barrel 4 is connected with the middle connecting sleeve 2 and sleeved on the central tube 1, and the other end of the outer barrel is connected with an upper connecting joint 5. The central tube 1 is of an internal hollow structure, one end of the central tube is connected with the outer tube 4 and is in butt joint with the upper connecting joint 5, the other end of the central tube is in butt joint with the lower connecting joint 6, and the middle connecting sleeve 2 and the piston sleeve 3 are respectively sleeved on the central tube 1. The outer wall of the central tube 1 is provided with a first convex part 11 and a first groove 12, and the first convex part 11 is positioned at one end of the outer wall of the central tube 1 far away from the intermediate connecting sleeve 2. One end of the middle connecting sleeve 2 is fixedly connected with the outer cylinder 4, one end of the middle connecting sleeve, which is close to the piston sleeve 3, extends to form a fixed cylinder 21, a second convex part 22 is arranged on the inner side of one end of the fixed cylinder 21, and the second convex part 22 is arranged in the first groove 12. The piston portion 31, the pressing portion 32 and the releasing portion 33 are disposed inside the piston sleeve 3, and the piston portion 31 is located at an end of the piston sleeve 3 away from the middle connection sleeve 2 and abuts against the first protrusion 11. The pressing portion 32 is located between the piston portion 31 and the releasing portion 33, and is used for pressing the second convex portion 22 of the fixed cylinder 21 into the first groove 12; one end of the relief portion 33 is connected to the intermediate connecting sleeve 2 by a connecting portion 34. The center tube 1 has a pressure transmission hole 13 formed therethrough at a position where the first convex portion 11 abuts against the piston portion 31. When pressure is applied to the inside of the central tube 1, the pressure is transmitted to the piston part 31 through the pressure transmission hole 13, so that the piston part 31 bears a first pressure in a direction away from the intermediate connecting sleeve 2, when the first pressure value is greater than a preset threshold value, one end of the release part 33 is separated from the intermediate connecting sleeve 2, the piston part 31 drives the piston sleeve 3 to move in the direction away from the intermediate connecting sleeve 2, the pressing part 32 is separated from the second convex part 22, the second convex part 22 is separated from the first groove 12, a cavity is formed between the release part 33 and the outer wall of the central tube 1, and the fixed tube 21 freely slides in the cavity, so that the intermediate connecting sleeve 2 freely slides along the central tube 1.

As shown in fig. 1, the overall structure schematic diagram of the telescopic short section provided by the embodiment of the present application is shown, the telescopic short section is used for connecting an upper connection joint 5 and a lower connection joint 6 together, the telescopic short section comprises an outer barrel 4, a central tube 1, an intermediate connection sleeve 2 and a piston sleeve 3, the outer barrel 4 is of an internal hollow structure, one end of the outer barrel 4 is connected with the upper connection joint 5, and can be hermetically connected through threads or riveting and the like, the other end of the outer barrel 4 is provided with the intermediate connection sleeve 2, and the intermediate connection sleeve 2 and the outer barrel 4 are jointly sleeved on the central tube 1. This intermediate connection cover 2 is used for cooperating with piston sleeve 3, when piston sleeve 3 suppressed the second convex part 22 on intermediate connection cover 2 in the first recess 12 on center tube 1 surface, then urceolus 4 and intermediate connection cover 2 and center tube 1 relatively fixed, when piston sleeve 3 removed, intermediate connection cover 2 was released, then urceolus 4 and intermediate connection cover 2 and center tube 1 can move about relatively, realize the length adjustment to flexible nipple joint, and then can adjust the distance between last attach fitting 5 that urceolus 4 is connected and the lower attach fitting 6 that is connected with center tube 1, realize the length compensation to the tubular column.

As shown in fig. 2 and 3, a specific structure of the base pipe 1 is shown, and the base pipe 1 is a hollow tubular structure, and the inner space of the hollow tubular structure is a channel for circulating a downhole fluid medium or tripping a downhole tool. The outside cover of center tube 1 is equipped with urceolus 4, and when urceolus 4 was connected with last attach fitting 5, the one end of center tube 1 was connected with last attach fitting 5, and the other end is connected with attach fitting 6 down for as the passageway that overflows of last attach fitting 5 and lower attach fitting 6, couple together last attach fitting 5 and lower attach fitting 6. In order to realize the regulation to the length of flexible nipple joint, in the outside of center tube 1, overlap respectively and be equipped with intermediate junction cover 2 and piston bush 3, intermediate junction cover 2 and the cooperation of piston bush 3 mutual butt. The middle connecting sleeve 2 and the outer cylinder 4 are fixedly arranged, the piston sleeve 3 is arranged on the outer wall of the central tube 1 and can move in a piston mode relative to the central tube 1, and the middle connecting sleeve 2 is pressed on the central tube 1 or released. Namely, the relative movement between the outer cylinder 4 and the central tube 1 is controlled by arranging the middle connecting sleeve 2 and the piston sleeve 3, and then the length of the telescopic short section is adjusted.

In order to realize the adjustment of the length of the telescopic short section, as shown in fig. 2 and 3, one end of the outer wall of the central tube 1, which is far away from the intermediate connecting sleeve 2, is provided with a first convex portion 11, when the piston sleeve 3 is sleeved on the first convex portion 11, the first convex portion 11 abuts against the inner surface of the piston sleeve 3, so as to position the piston sleeve 3, and simultaneously limit the moving direction of the piston sleeve 3, so that the piston sleeve 3 can only move along the central tube 1 in the direction far away from the intermediate connecting sleeve 2. The outer wall of the central tube 1 is provided with a first groove 12 at one end close to the first protrusion 11. The first groove 12 is adjacent to the first convex portion 11, the piston sleeve 3 can be sleeved outside the first convex portion 11 and the first groove 12, the first groove 12 is used for accommodating the second convex portion 22 at one end of the middle connecting sleeve 2, when the piston sleeve 3 is sleeved outside the first groove 12, the second convex portion 22 at one end of the middle connecting sleeve 2 can be pressed in the first groove 12, and then the outer cylinder 4 and the central pipe 1 are relatively fixed by fixing the middle connecting sleeve 2.

Fig. 2 and 4 show the structure diagram of the middle connection sleeve 2, one end of the middle connection sleeve 2 is fixedly connected with the outer cylinder 4, one end close to the piston sleeve 3 extends to be provided with a fixed cylinder 21, the fixed cylinder 21 is of a cylindrical structure and is sleeved on the central tube 1, a second convex part 22 is arranged on the inner side of one end of the fixed cylinder 21, when the telescopic short section is not started, the second convex part 22 is located in the first groove 12 on the outer wall of the central tube 1, the piston sleeve 3 presses the second convex part 22 in the first groove 12 on the central tube 1, so that the fixed cylinder 21 and the middle connection sleeve 2 cannot move on the central tube 1, and the outer cylinder 4 and the central tube 1 are relatively fixed. In order to realize the lifting and recovery of the whole underground pipe column and better transfer the pulling force of the pipe column, the central pipe 1, the intermediate connecting sleeve 2 and the outer cylinder 4 are made of hard materials with certain strength, such as metal materials. The fixed cylinder 21 may be constructed in various ways, for example, one or more connecting claws may be symmetrically arranged on both sides of the middle connecting sleeve 2. Fig. 5 shows a structural schematic diagram of the fixed cylinder 21 proposed in the embodiment of the present application, and one end of the connecting claw is provided with a second protrusion 22, and the second protrusion 22 is pressed into the first groove 12, so that the fixing of the outer cylinder 4 can be also achieved, and the intermediate connecting sleeve 2 and the outer cylinder 4 are further fixed.

As shown in fig. 2 and 6, which illustrate the structure of the piston sleeve 3, the piston sleeve 3 includes a piston portion 31, a pressing portion 32 and a releasing portion 33, the piston sleeve 3 is integrally sleeved on the central tube 1, and the pressing portion 32 and the releasing portion 33 of the piston sleeve 3 are sleeved on the intermediate connecting sleeve 2 and connected with the outer surface of the intermediate connecting sleeve 2 through a connecting portion 34. As shown in fig. 6, the piston portion 31, the pressing portion 32, and the releasing portion 33 are stepped, the piston portion 31 is disposed corresponding to the first protrusion 11 of the center tube 1, and the inner wall of the piston portion 31 abuts against the first protrusion 11 to seal the piston sleeve 3 and the outer wall of the center tube 1, thereby forming a piston chamber. The center tube 1 is provided with a pressure transmission hole 13 at a position where the first convex portion 11 abuts against the piston portion 31. As shown in fig. 2, the pressure transmission hole 13 is located at the abutting position of the first protrusion 11 and the piston part 31 in the piston part 31, and communicates the piston part 31 and the hollow interior of the central tube 1, and since the abutting position of the first protrusion 11 and the piston part 31 has a certain pressure accommodating space, when the pressure is transmitted to the piston part 31 through the pressure transmission hole 13, a piston cavity is formed at the abutting position in the piston part 31, and a force for pushing the piston sleeve 3 away from the intermediate connecting sleeve 2 is generated, so that the piston sleeve 3 performs piston-type movement along the central tube 1.

The pressing part 32 is arranged corresponding to the first groove 12 of the central tube 1, and is used for pressing the second convex part 22 in the first groove 12 when the second convex part 22 of the middle connecting sleeve 2 is positioned in the first groove 12 of the central tube 1, so that the outer tube 4 and the central tube 1 are relatively fixed together.

A certain space is formed between the inner wall of the release part 33 and the central tube 1, one end of the release part 33 is connected with the intermediate connecting sleeve 2 through the connecting part 34, and the space formed between the release part 33 and the central tube 1 can be used for the second convex part 22 of the intermediate connecting sleeve 2 to move freely.

Before starting, as shown in fig. 1, the pressing portion 32 on the piston sleeve 3 presses the second protrusion 22 on the intermediate connecting sleeve 2 into the first groove 12 on the central tube 1, and the second protrusion 22 cooperates with the first groove 12 to fix the intermediate connecting sleeve 2 on the central tube 1 and further fix the outer tube 4 and the central tube 1 relatively.

When the length of the telescopic short section needs to be adjusted, a first pressure is applied to the hollow interior of the central tube 1, the first pressure is transmitted to the piston part 31 through the pressure transmission hole 13, referring to fig. 7, the piston sleeve 3 is pushed by the pressure transmitted by the piston part 31, after a preset pressure threshold is reached, the connecting part 34 at one end of the releasing part 33 on the piston sleeve 3 is pressed and disconnected, so that the piston sleeve 3 is disconnected from the intermediate connecting sleeve 2, the piston sleeve 3 can be pushed by the pressure to slide, the pressing part 32 moves along with the piston sleeve 3 until the second convex part 22 is not pressed, the releasing part 33 on the piston sleeve 3 moves along with the piston sleeve to the second convex part 22, and a cavity is formed between the releasing part 33 and the central tube 1 due to the fact that a gap between the releasing part 33 and the central tube 1 is large, so that the second convex part 22 can be easily rebounded and separated from the first groove 12. When the second convex part 22 is separated, the middle connecting sleeve 2 can move axially along the central tube 1, so that the outer tube 4 can move axially along the central tube 1, and when a tensile force is applied to the upper connecting joint 5, the upper connecting joint 5 drives the outer tube 4 to move relative to the central tube 1, so that the length of the tube column is compensated.

The first pressure is a pressure transmitted from the center tube 1 to the piston portion 31 through the pressure transmission hole 13, and may be a pneumatic pressure or a hydraulic pressure. The pressure required to separate one end of the release portion 33 on the piston sleeve 3 from the intermediate connecting sleeve 2 is a preset pressure threshold, and the preset pressure threshold can be adjusted by changing the connection strength between the connecting portion 34 on one end of the release portion 33 and the intermediate connecting sleeve 2, or by changing the number of the connecting portions 34.

This application embodiment is through connecting urceolus 4 and central tube 1 through intermediate junction cover 2 and piston sleeve 3 to set up pressure transmission hole 13 on central tube 1, and connect intermediate junction cover 2 and piston sleeve 3 with the mode that can cut, because connecting portion 34 on the flexible nipple joint does not directly bear axial pressure, avoided the unexpected start of operation process in the pit or in the pit, it is particularly favorable to the stability of operation. Meanwhile, by adopting the injection-pressure opening mode, when the opening extension section is shortened, only injection pressure is needed to be injected into the pipe column, and no axial load is needed to be additionally provided, so that the starting difficulty is reduced, and the operation timeliness and the operation cost are reduced. Meanwhile, the piston sleeve 3 and the middle connecting sleeve 2 are arranged together through the connecting part 34 with the shearing function, so that the piston sleeve 3 and the middle connecting sleeve 2 can be conveniently disconnected, and the structure is simple and convenient to operate.

According to some embodiments of the present application, referring to fig. 1 and 3, and further referring to fig. 4, a guide groove 15 is provided in an axial direction at a position corresponding to the intermediate connecting sleeve 2 on an outer wall of the center pipe 1, a guide portion 23 is provided on an inner surface of the intermediate connecting sleeve 2, the guide portion 23 is provided in the guide groove 15, and the intermediate connecting sleeve 2 moves along the guide groove 15.

A guide groove 15 is axially arranged at a position on the outer wall of the central tube 1 corresponding to the middle connecting sleeve 2, a guide part 23 is arranged on the inner surface of the middle connecting sleeve 2, and the guide groove 15 and the guide part 23 are matched to limit the rotation of the middle connecting sleeve 2, so that the middle connecting sleeve 2 can only move axially along the central tube 1. The guide grooves 15 and the guides 23 can also transmit torque to each other for the center tube 1 and the intermediate coupling sleeve 2, because the rotation of the intermediate coupling sleeve 2 is restricted. The guide groove 15 may be an elongated groove provided along the axial direction of the center tube 1, and the guide portion 23 may be a protrusion. In addition, an opening can also be formed in the outer surface of the middle connecting sleeve along the axial direction, the guide part 23 is arranged in the opening, so that the guide part 23 moves along the axial direction of the guide groove 15, and the guide part 23, the opening and the guide groove 15 are matched to limit the middle connecting sleeve 2, so that the middle connecting sleeve 2 can only move along the axial direction of the central tube 1 and transmit torque. In order to allow the guide portion 23 to perform the function of transmitting torque, the guide portion 23 should be made of a material having a certain hardness, such as a metal material.

When the middle connecting sleeve 2 moves axially to realize length compensation, the guide groove 15 and the guide part 23 can improve the stability of the movement of the middle connecting sleeve 2 and reduce the fault probability of the structure. Meanwhile, when torque needs to be applied to the underground pipe column and the telescopic short joint, the torque can be transmitted through the guide groove 15 and the guide part 23.

According to some embodiments of the present application, referring to fig. 2 and 3, the outer wall of the central tube 1 is provided with sealing structures 14 at positions on both sides of the pressure transfer hole 13, and the piston portion 31 forms a closed space with the outer wall of the central tube 1 through the sealing structures 14.

The sealing structures 14 are respectively arranged on two sides of the pressure transmission hole 13 on the outer wall of the central tube 1, and the sealing structures 14 are used for forming a closed space in the piston part 31 and preventing the pressure transmitted to the piston part 31 through the pressure transmission hole 13 from leaking. In addition to providing the sealing structures 14 on both sides of the pressure transmission hole 13, there is a possibility that pressure leaks between the central tube 1 and the outer tube 4 or the intermediate connection sleeve 2 at the joint between the central tube 1 and the upper connection joint 5 and the lower connection joint 6 due to insufficient sealing performance of the connection portion 34, so that the pressure in the column is difficult to maintain, sufficient pressure cannot be transmitted to the piston portion 31 in the piston sleeve 3, and normal disconnection of the connection portion 34 is affected, and in order to further ensure stable transmission of pressure, an additional sealing structure may be provided between the central tube 1 and the intermediate connection sleeve 2 to prevent pressure leakage.

When exerting pressure to center tube 1, in center tube 1 internal pressure transmitted piston portion 31 through passing pressure hole 13, owing to pass pressure hole 13 both sides all to be equipped with seal structure 14, make pressure be difficult for revealing, can be better act on piston portion 31, and then guaranteed that piston sleeve 3 can be promoted by pressure, reduced piston sleeve 3 because pressure is revealed unable probability that leads to starting failure to reach the pressure threshold value, improved the stability of structure operation.

According to some embodiments of the present application, referring to fig. 3 and 6, the sealing structure 14 is a sealing rubber ring.

Sealing rubber rings are adopted as sealing structures 14 on two sides of the pressure transfer hole 13 in the central tube 1 to seal the interior of the piston part 31. In addition, an inflatable sealing device can be used for sealing.

By using the sealing structure 14 for sealing, the pressure in the piston portion 31 can be ensured to act on the piston sleeve 3 better, and the failure caused by pressure leakage is avoided.

According to some embodiments of the present application, the connection 34 is a shear pin.

One end of a release part 33 on the piston sleeve 3 is connected with the middle connecting sleeve 2 through a shearing pin, when the pressure in the piston part 31 reaches a threshold value to disconnect the shearing pin, one end of the release part 33 is separated from the middle connecting sleeve 2, and the piston sleeve 3 can move. The number of shear pins can be adjusted and by adjusting the number of shear pins, a pressure threshold can be set for separating the relief 33 from the intermediate connection sleeve 2. In addition, the connecting portion 34 may also be a magnetic structure. Contain a plurality of when stretching to shorten the festival in the tubular column in the pit, can set up the shearing pin of different intensity or different quantity through flexible nipple joint for the difference to make different flexible nipple joints can stretch out and draw back respectively according to the intensity of the pressure of exerting and adjust, increased the flexibility of adjusting tubular column in the pit.

The pin is sheared to enable one end of the releasing part 33 to be connected with the middle connecting sleeve 2 and separated under the action of the piston sleeve 3 driven by pressure. When the extension and shortening period needs to be started, pressure is applied to the center tube 1, the pressure is transmitted to the piston part 31 through the pressure transmitting hole 13, the piston part 31 is stressed in the direction of keeping away from the middle connecting sleeve 2 under the action of pressure, when the pressure is enough to enable the piston sleeve 3 to break the shearing pin, the shearing pin is broken, the piston sleeve 3 is not connected with the center connecting tube, and the telescopic short section is started. Meanwhile, the shear pin also has certain structural strength, and is not easy to start in advance by accident. In the operation is retrieved to tubular column in the pit, can also realize different start pressure threshold values through the quantity of the shear pin of adjustment different degree of depth extending structure, make operating personnel can open step by step and layered control flexible nipple joint, improved suitability and convenience.

According to some embodiments of the present application, an end of the center tube 1 near the intermediate coupling sleeve 2 is provided with a stopper 16, and the stopper 16 is used to limit the stroke of the intermediate coupling sleeve 2 when the intermediate coupling sleeve 2 moves axially.

One end of the central tube 1 close to the middle connecting sleeve 2 is provided with a blocking part 16, and the blocking part 16 can be abutted against the middle connecting sleeve 2 to prevent the middle connecting sleeve 2 from continuously moving after the middle connecting sleeve 2 axially moves for a certain position, so that the effect of limiting the stroke of the middle connecting sleeve 2 is realized. The stroke of the middle connecting sleeve 2 is related to the length of the middle connecting sleeve 2 and the spacing distance between the stopping part 16 and the middle connecting sleeve 2, and the length of the middle connecting sleeve 2 or the position of the stopping part 16 can be adjusted according to actual requirements, so that the stroke of the middle connecting sleeve 2 is set.

When the piston sleeve 3 slides and the second protrusion 22 on the intermediate connecting sleeve 2 is disengaged from the first groove 12 on the central tube 1, the intermediate connecting sleeve 2 can move axially along the central tube 1, so that length compensation is realized. When the pipe column is lifted up to recover the telescopic short section and the pipe column, the telescopic short section is exerted to lifting tension, the lifting tension drives the middle connecting sleeve 2 to move to abut against the blocking part 16 on the central pipe 1, and then the lifting tension is transmitted to the central pipe 1 through the blocking part 16, so that the central pipe 1 can be synchronously pulled up to be recovered.

According to some embodiments of the present application, the stopper 16 is threadedly provided at one end of the center pipe 1, and the outer diameter of the stopper 16 is larger than the inner diameter of the intermediate coupling sleeve 2.

The stopping part 16 is fixedly sleeved at one end of the central tube 1 through threads, and in order to enable the stopping part 16 to be abutted against the middle connecting sleeve 2 and achieve the effect of stopping the movement of the middle connecting sleeve 2, the outer diameter of the stopping part 16 must be larger than the inner diameter of the middle connecting sleeve 2. In addition, the blocking portion 16 may be fixed and sleeved on the central tube 1 by welding or clamping, which is not particularly limited in this embodiment.

The stopping part 16 is arranged at one end of the central tube 1 through threads, so that the replacement of equipment parts is facilitated, when the intermediate connecting sleeves 2 with different sizes are replaced according to actual conditions, the stopping part 16 matched with the intermediate connecting sleeves 2 can be replaced more conveniently and synchronously through the threads, and the applicability of the equipment is improved. Meanwhile, the blocking part 16 can bear larger axial force in a butting mode that the outer diameter is larger than the inner diameter of the middle connecting sleeve 2, the central tube 1 can be pulled up better and synchronously when the tubular column and the telescopic short section are pulled up, and certain stability is guaranteed.

According to some embodiments of the present application, referring to fig. 4 and 5, the fixed cylinder 21 includes a plurality of elastic extensions 24, each elastic extension 24 being disposed at intervals in an axial direction of the fixed cylinder 21, and the second protrusion 22 being disposed at one end of the elastic extension 24.

The elastic extensions 24 and the second protrusions 22 included in the fixed cylinder 21 together form an elastic claw structure, when the second protrusion 22 at one end of the elastic extension 24 moves to the first groove 12 on the central tube 1, the elastic extension 24 has elasticity, so that the elastic extension 24 can drive the second protrusion 22 to be embedded in the first groove 12, and when the pressing portion 32 presses the second protrusion 22, the elastic extension 24 and the second protrusion 22 can be fixed with the central tube 1, so that the intermediate connecting sleeve 2 cannot move.

The elastic claw structure formed by the elastic extension parts 24 and the second convex part 22 can bear larger axial load, so that the structure operation of the telescopic short section is more stable and reliable.

According to some embodiments of the present application, referring to fig. 1 and 7, the present application further provides a downhole tubular string comprising a tubular string body and a telescopic short section as described above, the telescopic short section being connected with the tubular string body.

The telescopic short section is connected with the tubular column body through threads to jointly form the underground tubular column so as to realize the length compensation of the tubular column. In addition, the telescopic short section and the tubular column body can be connected with each other by welding or clamping, and the embodiment does not specially limit the telescopic short section and the tubular column body. When the packer deblocking that needs made the tubular column, through exerting pressure in to center tube 1, make piston portion 31 promote piston sleeve 3 break away from intermediate junction cover 2, make the portion of compressing tightly 32 on the piston sleeve 3 no longer sticis the second convex part 22 of the solid fixed cylinder 21 on the intermediate junction cover 2, intermediate junction cover 2 can be followed the axial activity of center tube 1, through applying last attach fitting 5 and lifting the tensile force and drive urceolus 4 and the flexible realization of intermediate junction cover 2 to the length compensation of tubular column, through length compensation, reach the effect of economizing when carrying the tubular column to carry out the deblocking at last.

Increase flexible nipple joint in the tubular column, when needs let the packer deblocking of tubular column in order to retrieve the tubular column, the length compensation that provides through flexible nipple joint makes the packer change the deblocking, solved because of there are a plurality of packers in whole tubular column, including the dead weight of tubular column and rub and hinder, the lifting of whole tubular column is because of well head hoisting device's ability is not enough and can't go on, the unable deblocking of top packer and the unable problem that plays of whole sand control tubular column, and then make whole tubular column retrieve more easily.

According to some embodiments of the present application, the tubular string body is a cylindrical structure with a hollow interior.

The interior cavity of the tubular column body that links to each other with flexible nipple joint, the inside of its cavity should link up with flexible nipple joint cavity inside and form vertical runner.

The flow passage formed in the hollow interior of the pipe column body can be used as a passage for the circulation of underground fluid media and can also be used as a passage for the laying down and the folding up of underground tools. When the packer deblocking of tubular column is required to be enabled, to the inside notes pressure of cavity of tubular column body, pressure transmits center tube 1 through the inside transmission of cavity of tubular column body, the piston portion 31 on piston sleeve 3 is transmitted to pressure transmission hole 13 on the rethread center tube 1, reach the pressure threshold value of connecting portion 34 after, connecting portion 34 disconnection, promote piston sleeve 3 and remove to the direction of keeping away from intermediate junction cover 2, make intermediate junction cover 2 and urceolus 4 can follow 1 axial activity of center tube, through applying to the tubular column body and lifting the pulling force and drive intermediate junction cover 2 and urceolus 4 flexible realization to the length compensation of tubular column. The mode of opening flexible nipple joint through the inside notes pressure of cavity to the tubular column body realizes the effect that can conveniently control in the pit and open.

Finally, it should be noted that: the above embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present disclosure, and the present disclosure should be construed as being covered by the claims and the specification. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present application is not intended to be limited to the particular embodiments disclosed herein but is to cover all embodiments that may fall within the scope of the appended claims.

Claims (10)

1. A telescopic short section is characterized by comprising an outer cylinder, a central pipe, a middle connecting sleeve and a piston sleeve;

the outer cylinder is of an internal hollow structure, one end of the outer cylinder is connected with the middle connecting sleeve and sleeved on the central pipe, and the other end of the outer cylinder is connected with the upper connecting joint;

the central tube is of an internal hollow structure, one end of the central tube is connected with the outer barrel and is in butt joint with the upper connecting joint, the other end of the central tube is in butt joint with the lower connecting joint, and the middle connecting sleeve and the piston sleeve are respectively sleeved on the central tube;

the outer wall of the central pipe is provided with a first convex part and a first groove, and the first convex part is positioned at one end, far away from the middle connecting sleeve, of the outer wall of the central pipe;

one end of the middle connecting sleeve is fixedly connected with the outer cylinder, one end of the middle connecting sleeve, which is close to the piston sleeve, extends to form a fixed cylinder, a second convex part is arranged on the inner side of one end of the fixed cylinder, and the second convex part is arranged in the first groove;

the inner side of the piston sleeve is provided with a piston part, a pressing part and a releasing part, and the piston part is positioned at one end of the inner side of the piston sleeve, which is far away from the middle connecting sleeve, and is abutted against the first convex part; the pressing part is positioned between the piston part and the releasing part and is used for pressing the second convex part of the fixed cylinder in the first groove; one end of the release part is connected with the middle connecting sleeve through a connecting part;

a pressure transmission hole is formed in the central pipe at the position where the first convex part is abutted to the piston part in a penetrating manner;

when to in the center tube applys pressure, pressure passes through pass the pressure hole to piston portion transmission makes piston portion is keeping away from bear first pressure in the direction of adapter sleeve, works as when first pressure value is greater than and predetermines the threshold value, release portion one end with the adapter sleeve separation, piston portion drives piston sleeve is to keeping away from the direction of adapter sleeve removes, compress tightly the portion with the separation of second convex part, the second convex part is followed throw off in the first recess, release portion with form the cavity between the center tube outer wall, the solid fixed cylinder is in freely sliding in the cavity, make the urceolus with the center tube relative slip.

2. The telescopic short section according to claim 1, wherein a guide groove is formed in an outer wall of the central pipe at a position corresponding to the intermediate connecting sleeve in the axial direction, a guide portion is formed on an inner surface of the intermediate connecting sleeve, the guide portion is disposed in the guide groove, and the intermediate connecting sleeve moves along the guide groove.

3. The telescopic short section according to claim 1, wherein sealing structures are respectively disposed on the outer wall of the central tube at positions on both sides of the pressure transfer hole, and the piston portion forms a closed space with the outer wall of the central tube through the sealing structures.

4. The telescopic sub of claim 3, in which the sealing structure is a sealing rubber ring.

5. The telescopic sub of claim 1, in which the connection is a shear pin.

6. The telescopic sub according to any one of claims 1 to 5, characterized in that one end of the central tube close to the intermediate connecting sleeve is provided with a stop portion for limiting the stroke of the intermediate connecting sleeve when the intermediate connecting sleeve moves axially.

7. The telescopic sub of claim 6, wherein the stop is threaded at one end of the central tube, the stop having an outer diameter greater than an inner diameter of the intermediate coupling sleeve.

8. The telescopic sub of claim 1, wherein the fixed cylinder includes a plurality of elastic extensions, each of the elastic extensions being disposed at intervals in an axial direction of the fixed cylinder, and the second protrusion being disposed at one end of the elastic extension.

9. A downhole string comprising a telescoping sub as claimed in any of claims 1 to 8 and a string body;

the telescopic short section is connected with the tubular column body.

10. A downhole string according to claim 9, wherein the string body is a hollow-inside cylindrical structure.

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