CN108086938B

CN108086938B - Packer

Info

Publication number: CN108086938B
Application number: CN201611049066.5A
Authority: CN
Inventors: 刘阳; 秦金立; 李洪春; 李奎为
Original assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Current assignee: China Petroleum and Chemical Corp; Sinopec Research Institute of Petroleum Engineering
Priority date: 2016-11-21
Filing date: 2016-11-21
Publication date: 2020-03-31
Anticipated expiration: 2036-11-21
Also published as: CN108086938A

Abstract

The invention relates to a packer, which comprises a cylindrical switch mandrel, wherein a first flow through hole is formed in the side wall of the switch mandrel; the rubber cylinder assembly is sleeved on the outer wall of the switch mandrel, and a liquid cavity of the rubber cylinder assembly is communicated with the first flow through hole; the inner sliding sleeve is arranged in the inner cavity of the switch mandrel and can move axially relative to the switch mandrel, a second flow through hole is formed in the side wall of the inner sliding sleeve, the inner sliding sleeve can move downwards relative to the switch mandrel to enable the first flow through hole and the second flow through hole to be communicated, the inner sliding sleeve can move upwards relative to the switch mandrel to enable the first flow through hole and the second flow through hole to be cut off, and the packer is convenient to set or unseal and wide in application range.

Description

Packer

Technical Field

The invention relates to the technical field of oil and gas field construction, in particular to a packer.

Background

Packers are important tools for sealing off the annulus in a well.

For example, the packer may be used in old wells that are re-fractured. After a period of time of fracturing well completion production of the low permeability oil and gas well, the fracture flow conductivity is gradually reduced. To increase the single well productivity, the potential for oil and gas well production is often re-fractured. Different from the fracturing of a new well, the repeated fracturing of an old well needs reliable mechanical packing of the existing cracks, a packer in a conventional double-packing single-clamp pipe column adopts a hydraulic expansion sealing structure, and the pipe can be expanded and sealed by throttling pressure difference, and is decompressed and unsealed. However, the old well is complicated in well condition, and needs to be pumped and injected in the pipe in the construction process, and the conventional packer is easy to expand and seal midway due to the existence of throttling pressure difference and surging pressure when liquid is pumped and injected in the oil pipe, and is not suitable for the complicated well condition of old well reconstruction.

Disclosure of Invention

In order to solve the problems, the invention provides a packer. The packer is high in safety and capable of remarkably improving the repeated transformation process of the low-efficiency well.

The packer according to the invention comprises:

a first flow through hole is arranged on the side wall of the cylindrical switch mandrel,

a rubber cylinder component sleeved on the outer wall of the switch mandrel, a liquid cavity of the rubber cylinder component is communicated with the first flow through hole,

an inner sliding sleeve which is arranged in the inner cavity of the switch core shaft and can axially move relative to the switch core shaft, a second flow through hole is arranged on the side wall of the inner sliding sleeve,

the inner sliding sleeve is configured to move downwards relative to the switch core shaft to enable the first flow through hole and the second flow through hole to be communicated, and can move upwards relative to the switch core shaft to enable the first flow through hole and the second flow through hole to be cut off.

In one embodiment, the packer further comprises:

a limit shaft which is arranged at the upper end of the inner sliding sleeve in a butt joint mode, a first shaft shoulder is arranged on the outer wall of the limit shaft,

an upper joint fixedly arranged at the upper end of the limiting shaft,

a limit sleeve fixedly arranged at the upper end of the switch core shaft and sleeved on the outer wall of the inner sliding sleeve,

a pressing cap sleeved on the outer wall of the limiting shaft, the pressing cap is fixedly connected with the limiting sleeve,

wherein, press the lower terminal surface of cap and set up the first step face on the inside wall of stop collar and form spacing space in the axial, first shoulder with set up including the equal radial extension of second shoulder on the sliding sleeve outer wall to spacing space in.

In one embodiment, a resilient member is disposed in a spacing space between the second shoulder and the first step surface.

In one embodiment, the elastic member is a spring sleeved on the outer wall of the inner sliding sleeve.

In one embodiment, the first and second flow holes are the same in shape and flow area.

In one embodiment, when the first flow through hole and the second flow through hole are cut off, sealing elements are respectively arranged at the upper end and the lower end of the first flow through hole between the inner sliding sleeve and the switch mandrel.

In one embodiment, the sealing element is a sealing ring and is sleeved on the outer wall of the inner sliding sleeve.

In one embodiment, the rubber sleeve assembly comprises a rubber sleeve and an upper limiting ring and a lower limiting ring which are respectively arranged at the upper end and the lower end of the rubber sleeve, and the upper limiting ring and the lower limiting ring are fixedly connected with the rubber sleeve in a vulcanization mode.

In one embodiment, a lower joint is fixedly arranged at the lower end of the switch mandrel, and a lower limiting ring is sleeved on the outer wall of the lower joint and can move along the axial direction of the lower joint.

In one embodiment, the pressing cap is in threaded connection with the stop collar, and the side wall of the pressing cap and the side wall of the stop collar are connected by a screw.

Compared with the prior art, the invention has the advantages that: the inner sliding sleeve of the packer can move upwards or downwards relative to the axial direction of the switch mandrel to cut off or communicate the first flow through hole and the second flow through hole, so that expansion sealing and retraction of the rubber sleeve assembly can be better controlled, and accidental expansion sealing of the packer in the process of pumping in the pipe is avoided.

Drawings

The invention will be described in more detail hereinafter on the basis of embodiments and with reference to the accompanying drawings. Wherein:

FIG. 1 schematically shows a state diagram of a packer according to the invention;

FIG. 2 schematically shows another state diagram of a packer according to the invention;

in the drawings, like parts are provided with like reference numerals. The drawings are not to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

FIG. 1 shows a packer 100 according to the present invention. As shown in fig. 1, the packer 100 comprises an upper joint 1, a limiting shaft 2, a pressing cap 3, a limiting sleeve 4, an inner sliding sleeve 5, a rubber sleeve component 7, a switch mandrel 8 and a lower joint 9.

Wherein, the upper joint 1 is a cylindrical structure and is used for being connected with an oil pipe or other downhole tools. The limiting shaft 2 is of a cylindrical structure and is arranged at the lower end of the upper joint 1 and fixedly connected with the upper joint 1. The pressing cap 3 is sleeved on the outer wall of the limiting shaft 2, and the lower end of the pressing cap is inserted into the inner cavity of the limiting sleeve 4 and is fixedly connected with the limiting sleeve. The upper end of the limiting sleeve 4 is sleeved on the outer wall of the limiting shaft 2, and a first step surface 41 is arranged in the inner cavity. The first step surface 41 is disposed opposite to the lower end surface of the press cap 3, and forms a limit space 40 in the axial direction. The upper end of the inner sliding sleeve 5 is arranged in the inner cavity of the limiting sleeve 4, and the upper end surface of the inner sliding sleeve is in face-to-face joint with the lower end surface of the limiting shaft 2. And, set up first shaft shoulder 21 on the outer wall of spacing axle 2, set up second shaft shoulder 51 on the outer wall of inner sliding sleeve 5. The first shoulder 21 and the second shoulder 51 each project radially outward to extend into the retaining space 40. Thus, when the limiting shaft 2 and the inner sliding sleeve 5 are forced to move axially, the limiting space 40 cooperates with the first shoulder 21 and the second shoulder 51 to limit the axial movement of the limiting shaft 2 and the inner sliding sleeve 5. A second flow through hole 52 is provided in the side wall of the inner slide sleeve 5. The switch mandrel 8 is sleeved on the outer side wall of the inner sliding sleeve 5 and is fixedly connected with the lower end of the limiting sleeve 4. And a first flow-through hole 81 is provided on the side wall of the switching spindle 8. During the axial movement of the inner sliding sleeve 5 relative to the switching mandrel 8, the second flow through hole 52 can be connected or disconnected with the first flow through hole 81. The rubber cylinder assembly 7 is arranged on the outer side wall of the switch mandrel 8, and the liquid cavity 71 of the rubber cylinder assembly is communicated with the first flow through hole 81. When the second flow through hole 52 is in communication with the first flow through hole 81, pressure fluid may be injected into the fluid chamber 71 through the inner cavity of the packer 100 to actuate the packing element 72 of the packing element assembly 7 to expand and seal, thereby sealing off the formation, as shown in FIG. 2.

An elastic member 6 is provided in the stopper space 40 between the second shoulder 51 and the first step surface 41. Preferably, the elastic member 6 is a spring sleeved on the outer wall of the inner sliding sleeve 5. After the upper joint 1 applies an axial downward force, the force is transmitted to the inner sliding sleeve 5 through the limiting shaft 2, and the inner sliding sleeve 5 moves downward after receiving the downward force, so that the second flow through hole 52 is close to and communicated with the first flow through hole 81. At this time, the spring is compressed. When the upper joint 1 is lifted up, the limiting shaft 2 moves upwards along with the upper joint 1. Under the elastic force of the spring, the inner sliding sleeve 5 moves upward, so that the second through hole 52 is far away from the first through hole 81 to stop the two. The packer 100 is easily operated by pressing down to connect the fluid chamber 71 of the packing element 7 with the inner chamber of the packer 100, thereby ensuring the expansion of the packing element 7. Meanwhile, the packer 100 can also stop the communication between the second through hole 52 and the first through hole 81 through the lifting operation, so that the liquid is blocked from entering the liquid cavity 71 of the rubber sleeve assembly 7, and the rubber sleeve assembly 7 is prevented from being expanded accidentally. Therefore, the packer 100 is high in safety, and can be repeatedly expanded and unsealed for many times, so that the construction efficiency is improved.

In a preferred embodiment, the first and second flow holes 81 and 52 are identical in shape and flow area. For example, the first and second flow through

holes

81 and 52 are each configured as a circular hole. By means of the arrangement, a large throttling pressure difference generated after the pressure fluid flows through the second through hole 52 and the first through hole 81 can be avoided, and therefore the expansion sealing stability of the rubber cylinder assembly 7 is guaranteed.

In one embodiment, when the first flow hole 81 and the second flow hole 52 are blocked, the sealing members 10 are respectively disposed at the upper and lower ends of the first flow hole 81 between the inner sliding sleeve 5 and the switching mandrel 8 for preventing the pressure fluid from entering the fluid chamber 71 through the first flow hole 81. Preferably, the sealing member 10 is a sealing ring and is sleeved on the outer wall of the inner sliding sleeve 5. The seal 10 may be provided on the outer wall of the opening/closing stem 8 at the upper and lower ends of the first flow through hole 81.

In one embodiment, the glue cartridge assembly 7 includes a glue cartridge 72, an upper confinement ring 73 and a lower confinement ring 74. An upper limit ring 73 and a lower limit ring 74 are provided at upper and lower ends of the rubber cylinder 72, respectively, for limiting the rubber cylinder 72. The upper limiting ring 73 and the lower limiting ring 74 are fixedly connected with the rubber cylinder 72 in a vulcanization mode. This packing element subassembly 7 simple structure, the security is high. Preferably, the upper limiting ring 73 is fixedly connected with the position-limiting sleeve 4, and the lower limiting ring sleeve 74 is sleeved on the outer wall of the lower joint 9. During the forced expansion or unsealing of the rubber sleeve 72, the lower limiting collar 74 can move axially on the outer wall of the lower joint 9 to compensate for the deformation caused by the rubber sleeve 72.

To facilitate assembly of the packer 100, the gland 3 is threadedly connected to the stop collar 4. By this arrangement, quick connection and disconnection can be ensured. In addition, a screw 11 is provided on the outer wall of the spacing sleeve 4 to further fix the pressing cap 3 and the spacing sleeve 4. Through the arrangement, the connection stability of the pressing cap 3 and the limiting sleeve 4 can be ensured, and accidents caused by loosening of threaded connection are prevented.

In this application, the azimuthal terms "upper" and "lower" are both referenced to the operating state of the packer 100.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A packer, comprising:

a rubber cylinder component sleeved on the outer wall of the switch mandrel, wherein a liquid cavity of the rubber cylinder component is communicated with the first flow through hole,

an inner sliding sleeve which is arranged in the inner cavity of the switch mandrel and can axially move relative to the switch mandrel, a second flow through hole is arranged on the side wall of the inner sliding sleeve,

an upper joint fixedly arranged at the upper end of the limit shaft,

a limit sleeve fixedly arranged at the upper end of the switch mandrel and sleeved on the outer wall of the inner sliding sleeve,

the inner sliding sleeve is constructed to be capable of moving downwards relative to the switch core shaft to enable the first flow through hole to be communicated with the second flow through hole and enable the first flow through hole to be stopped with the second flow through hole to be stopped, the lower end face of the pressing cap and a first step face arranged on the inner side wall of the limiting sleeve form a limiting space in the axial direction, the first shaft shoulder and a second shaft shoulder arranged on the outer wall of the inner sliding sleeve radially extend into the limiting space, and an elastic piece is arranged in the limiting space between the second shaft shoulder and the first step face.

2. The packer of claim 1, wherein the elastic member is a spring fitted over an outer wall of the inner sliding sleeve.

3. A packer as claimed in claim 1, wherein the first and second flowthrough holes are of the same shape and flow area.

4. The packer as claimed in claim 1, wherein when the first through hole and the second through hole are cut off, sealing members are respectively disposed at upper and lower ends of the first through hole between the inner sliding sleeve and the switch mandrel.

5. The packer of claim 4, wherein the sealing element is a sealing ring and is sleeved on an outer wall of the inner sliding sleeve.

6. The packer of claim 1, wherein the packing element assembly comprises a packing element and an upper limiting ring and a lower limiting ring which are respectively arranged at the upper end and the lower end of the packing element, and the upper limiting ring and the lower limiting ring are fixedly connected with the packing element in a vulcanization mode.

7. A packer as claimed in claim 6, wherein a lower sub is fixedly arranged at the lower end of the switch mandrel, and the lower limiting ring is sleeved on the outer wall of the lower sub and can move along the axial direction of the lower sub.

8. A packer as claimed in any one of claims 1 to 7, wherein the gland is threadedly connected to the stop collar and a screw is used to connect a side wall of the gland to a side wall of the stop collar.