CN214118146U - Self-balancing mechanism of packer - Google Patents

Abstract

The utility model discloses a self-balancing mechanism of packer, it includes: the central tube, the balance piston, the limiting ring, the limiting locking block, the limiting pin and the deblocking sleeve are designed on one side of the packer, which is far away from the setting piston, so that the deblocking pin can be prevented from being cut off when the side is subjected to external high pressure, and a locking mechanism can be damaged; the external pressure-bearing capacity of one side of the packer, which is deviated from the setting piston, is greatly improved, so that the packer bears high pressure in two directions.

Description

Self-balancing mechanism of packer

Technical Field

The mechanism of the utility model is designed on one side of the packer departing from the setting piston, which can prevent the side from shearing the deblocking pin when the side is subjected to external high pressure and destroy the locking mechanism; the external pressure-bearing capacity of one side of the packer, which is deviated from the setting piston, is greatly improved, so that the packer bears high pressure in two directions.

Background

The Y341 packer commonly used in the oil field at present is limited by the setting and sealing principle, and has the following problems: 1. The pressure-bearing capacity difference of the rubber cylinders is obvious, the external pressure-bearing capacity of one side close to the setting piston is high, and the external pressure-bearing capacity of one side far away from the setting piston is low; 2. the external pressure bearing capacity of the side, which is far away from the setting piston, is greatly influenced by the shearing strength of the unsetting pin, and the side bears excessive external pressure, so that the locking mechanism of the packer is directly damaged, and the packer is automatically unset; 3. increasing the shear strength of the unset pin will make it more difficult to lift the tubular string unset packer up, and thus it is impractical to increase the external pressure bearing capacity of the side away from the setting piston by increasing the shear strength of the unset pin.

SUMMERY OF THE UTILITY MODEL

In view of the above-mentioned drawbacks of the prior art, the present invention provides a self-balancing mechanism for a packer to overcome the above-mentioned drawbacks.

The technical scheme (as figure 1) of the utility model is that:

a self-balancing mechanism of a packer is characterized in that a hydraulic balance piston is additionally arranged on one side, away from a setting piston, of a rubber cylinder; when the central pipe is set with high pressure, the balance piston helps the packer to set; when the packer is subjected to a high pressure difference on the side of the packing element facing away from the setting piston after setting (relative to the middle fling abuses pipe and the side close to the setting piston), the high pressure acts on the balance piston, and the piston force generated on the balance piston prevents the locking mechanism of the packer from being damaged, thereby improving the pressure bearing capacity of the outer part of the side of the packer.

On the basis of the technical scheme, the method further comprises the following technical scheme:

the limiting locking block 4 is two semicircles, the inner side of the limiting locking block sinks in the groove of the central tube 1, the outer side of the limiting locking block is wrapped and surrounded by the limiting ring 3, the limiting ring 3 is connected with the limiting locking block through a plurality of limiting pins 5, and therefore the limiting locking block is prevented from radially expanding

The limiting locking block 4 is two semicircles, the inner side of the limiting locking block sinks in the groove of the central tube 1, the outer side of the limiting locking block is limited by the limiting ring 3 and cannot be radially expanded, and the axial direction of the limiting locking block is limited by the groove of the central tube 1 and cannot move, so that the limiting locking block can bear enough shearing force.

The length of the limiting ring 3 is slightly smaller than that of the limiting locking block 4, the balance piston 2 can only abut against the limiting locking block 4 when moving downwards, so that the limiting ring 3 is not affected by shearing force in the axial direction, and the limiting pin 5 is not affected by shearing force and is not easy to lose efficacy.

The balance piston 2 is positioned in an annular space enclosed by the unpacking sleeve 6 at the upper end of the packer and the central pipe 1, the lower part of the balance piston is limited by the limiting locking block 4, and the upper part of the balance piston is limited by an inner step of the unpacking sleeve 6.

The top of the valve cover 7 is milled with a certain number of longitudinal grooves, so that the valve cover can be radially opened and closed under a certain condition to change the inner drift diameter of the top.

When the packer is set (the pressure of the central pipe is higher than that of the sleeve 8), the balance piston 2 moves downwards, the piston force acts on the limiting locking block 4 and drives the central pipe to move downwards, and the function of the balance piston is to help the packer to set; when the packer bears external high pressure (the pressure of the sleeve 8 is higher than the pressure of the central pipe and the external pressure of the setting piston end), the balance piston 2 moves upwards, the piston force of the balance piston acts on the inner step of the unpacking sleeve 6 to push the unpacking sleeve 6 to move upwards, so that most of the piston force of the external high-pressure driving rubber sleeve group moving downwards is offset, the unpacking pin 7 is not easily sheared by the external high-pressure piston force of the side, and the external pressure bearing capacity of the side of the packer is greatly improved.

Because of above-mentioned technical scheme's application, the utility model discloses compare with current ordinary hydraulic packer after hydraulic packer is added to the structure and have following advantage:

1. the side of the packer facing away from the setting piston can also be subjected to high external pressure (relative to the central fling abuses tube and the side near the setting piston); 2. the pin is not required to be unsealed by the packer, the shearing strength is not required to be greatly improved, and the unsealing difficulty is not increased; 3. the whole design structure of the packer is not damaged, the number of added accessories is small, and the implementation is easy.

Drawings

The invention will be further described with reference to the following drawings and examples:

fig. 1 is a schematic cross-sectional view of the present invention;

fig. 2 is a schematic view of the principle of assisting in setting when the balance piston 2 of the present invention is set;

fig. 3 is the self-balancing principle schematic diagram of the balance piston 2 when the packer receives external high pressure.

Detailed Description

Example (b): referring to fig. 1, the present invention provides a self-balancing mechanism for a packer, in particular embodiment: the packer is a Y341 type non-backwashing packer capable of being unlocked by lifting, and one side of the upper joint is the side departing from the setting piston. An annular groove is processed at a proper position on the central tube 1, the inner sides of two semicircular limiting locking blocks 4 sink into the groove, and the limiting ring 3 externally surrounds the outer side of the limiting locking blocks and is connected with the limiting locking blocks through a plurality of limiting pins 5. The axial direction of the limiting locking block 4 is limited by the annular groove on the central tube 1, and the radial direction is limited by the limiting ring, so that the limiting locking block 4 and the central tube 1 are locked into a whole and can bear enough shearing force. The balance piston 2 is positioned in an annular space enclosed by the unpacking sleeve 6 at the upper end of the packer and the central pipe 1, the lower part of the balance piston is limited by the limiting locking block 4, and the upper part of the balance piston is limited by an inner step of the unpacking sleeve 6.

The balance piston 2 helps the setting principle when setting, as shown in figure 2: when the packer seals, the setting internal pressure of center tube 1 is higher than the external pressure (the packer deviates from the external pressure of one side of setting piston), and balanced piston 2 is down spacing by spacing locking piece 4 under this pressure differential effect, and axial displacement can not take place for spacing locking piece 4 and center tube 1 to drive center tube 1 and drive the unpacking cover 6 down, help the packing element compression to set, and also can't take place relative displacement between center tube 1 and the unpacking cover 6, can not cut deblocking pin 7.

The self-balancing principle of the balance piston 2 when the packer is subjected to external high pressure is as shown in figure 3: when deviating from one side of setting piston and bearing outer high pressure after the packer is set, external pressure (the pressure of sleeve pipe 8) is higher than interior pressure (center tube pressure), balance piston 2 goes upward, its piston force is used for on the interior step of the cover 6 of separating, promote the cover 6 of separating and go upward, thereby offset the descending piston force of most outside high-pressure drive packing element group, make deblocking pin 7 be difficult for being cut by the outer highly compressed piston force of this side, thereby under the condition that does not improve deblocking pin intensity, improve the outside bearing capacity of this side of packer by a wide margin.

The utility model relates to a setting, the sealed principle of rubber seal, packer do not be the scope of this patent application protection, do not give the repeated description here.

The above-mentioned embodiments are only for illustrating the technical concept and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to implement the present invention, which should not be construed as limiting the scope of the present invention. All equivalent changes or modifications made according to the spirit of the main technical solution of the present invention should be covered within the protection scope of the present invention.

Related terms:

1. setting: process for switching packer-like tool from standby state to working state

2. Pressure bearing: abbreviation for object resisting high pressure

3. Deblocking: process for changing packer type tool from working state to non-working state

4. Pressure: the pressure referred to in this patent application refers to the common name of physical pressure in the industry, not the name of physical pressure

5. Piston force: when two fluids with different pressures which are not communicated with each other act on the same object, a certain acting force is generated on the object, the object moves towards the direction with small acting force, and the difference value of the acting forces is called as piston force for short.

Claims (1)

1. The self-balancing mechanism of the packer is characterized in that: it includes: the device comprises a central tube (1), a balance piston (2), a limiting ring (3), a limiting locking block (4), a limiting pin (5) and an unsealing sleeve (6);

the limiting locking block (4) is in a shape of two semicircles, the inner side of the limiting locking block sinks in the groove of the central tube (1), the outer side of the limiting locking block is wrapped and surrounded by the limiting ring (3), the limiting ring (3) is connected with the limiting locking block through the multiple limiting pins (5), so that the radial expansion and the axial displacement of the limiting locking block are prevented, and the length of the limiting ring (3) is slightly smaller than that of the limiting locking block (4), so that the limiting ring (3) is not affected by the shearing force in the axial direction;

the balance piston (2) is positioned in an annular space formed by the unpacking sleeve (6) at the upper end of the packer and the central pipe (1), the lower part of the balance piston is limited by the limiting locking block (4), and the upper part of the balance piston is limited by the inner step of the unpacking sleeve (6).

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