RU2464407C1 - Device to drive packer seal - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: proposed device comprises case made up of branch pipe with cylindrical cavity made in its wall to be filled with fluid and two holes to communicate the latter with seal, plug fitted in cylindrical cavity, slide valve piston with spring and bush fitted on piston rod with spaced apart first and second pins and ring provided with shaped slots arranged there between to limit piston displacement between said holes, thrust arranged on piston between bush and spring, and seal rings. Said ring with shaped slots represents a solid body while bush is furnished with third and fourth spaced apart pins arranged to make axes of said first, second, third and fourth pins are located along appropriate diametral lines of the bush. Note here that piston spring is fitted in plug.

EFFECT: higher reliability and expanded performances at high pressure differences.

4 cl, 10 dwg

Description

The invention relates to the oil and gas industry and is intended to actuate the sealing assembly of the packer during the separation of layers.

A device is known for supplying fluid to the sealing element of the packer, comprising a pipe body with a cylindrical cavity made in its wall and filled with liquid and two holes for communicating the latter with the sealing element, a spring-loaded spool with a limiter for its movement, mounted in the cylindrical cavity between the holes with the possibility of their communication with each other during axial movement (see USSR author's certificate No. 1701892, class E21B 33/12, publ. 12/30/1991).

However, this device has significant drawbacks, in particular, when using it there is a danger of premature packer operation when the discharge line breaks, significant depressurization of the column, etc. In the event of a pressure drop in the column, the spool during its movement leads to premature actuation of the valve device, that is, an emergency situation is created. In addition, this packer cannot be installed in the upper intervals of the wellbore, where due to the insignificant pressure difference between the annulus and the annulus, the packer is not always prepared for operation.

The specified device is impractical to use to isolate a productive formation of low power when installing several packers, as it is not possible to sequentially actuate them from the bottom up.

The design of the known device is difficult to manufacture.

The closest technical solution adopted for the prototype is a device for actuating the sealing element of the packer, comprising a pipe body with a cylindrical cavity made in its wall and two holes for communicating the latter with the sealing element, a spool with a spring and a limiter for its movement, installed in a cylindrical cavity between the holes with the possibility of their communication with each other during axial movement, and the sealing rings, the spool being made in the form of a piston with an axis, on which has a sleeve with stops (pins), asymmetrically offset from each other, and between the stops (pins) there is a spool stop, made in the form of a split ring with curly grooves (see RF patent No. 2096583 for the invention, CL Е21В 33/12 , publ. 11/20/1997, the prototype).

Due to the placement on the axis of the piston-spool of the sleeve with displaced stops, between which there is a limiter for moving the valve, which is a split ring with curly grooves, it is possible to repeatedly create and relieve excess pressure in the casing due to the consistent interaction of the stops of the sleeve with curly grooves limiter, which eliminates the premature operation of the device with unforeseen pressure drops in the process of cementing wells.

The main disadvantage of the known design is the extremely low reliability, since the ring with curly grooves (step limiter for moving the piston-spool) is split. Moreover, the complexity of ensuring the required manufacturing accuracy of the diametrical dimensions of the specified split ring increases the complexity of manufacturing and the cost of the device. The low reliability of the device is due to the fact that the cavity in the pipe body, where a ring with curly grooves and a sleeve with stops are installed, is connected to the internal passage channel of the casing. Thus, small abrasive particles contained in the drilling fluid can fall into the gap between these elements and lead to their jamming. The device withstands a small pressure drop due to the fact that it has only two limit stops (pins).

The technical result of the invention is to increase the reliability of the device and expand the scope due to the ability to work with large pressure drops.

The technical result is achieved by the fact that in the device for actuating the sealing element of the packer, including the housing-pipe with a cylindrical cavity made in its wall for filling with liquid and two holes for the latter to communicate with the sealing element, a plug placed in the cylindrical cavity, a piston-spool with a spring, on the axis of which a sleeve is placed with first and second pins displaced relative to each other, between which a ring with curly grooves is installed to limit movement the piston-spool located in the cylindrical cavity between these holes with the possibility of their communication with each other during axial movement, the emphasis located on the piston-spool between the sleeve and the spring, and the o-rings, the ring with curly grooves made solid, the sleeve is equipped with offset relative to the other, the third and fourth pins mounted on the sleeve so that the axis of the first, third pins and the axis of the second, fourth pins are located on the respective diametrical lines of the bushings ki, with the piston-spool spring installed in the plug.

It is advisable that the first, second pins and the third, fourth pins are respectively offset relative to each other by an angle of 7 to 25 degrees to the axis of the sleeve.

The first, third pins and the second, fourth pins, it is advisable to place symmetrically with respect to the corresponding diametrical lines of the sleeve.

It is advisable that the first, second, third and fourth pins are made with a diameter of from 0.8 mm to 3.2 mm.

When conducting patent research, no solutions were found that are identical to the claimed, and therefore, the proposed solution meets the criterion of "novelty." The invention does not follow explicitly from the known solutions, therefore, the proposed invention meets the criterion of "inventive step".

Figure 1 shows the device in the initial (transport position) in the context.

Figure 2 depicts the device after creating a pressure in the casing (after receiving the signal "STOP").

Figure 3 shows the device after depressurization (after receiving the signal "STOP").

Figure 4 shows the device in the mode of "Packing".

Figure 5 - device when depressurizing after the mode of "Packing".

In Fig.6 - the device in the mode "Dopakovka".

Fig.7 depicts a device when depressurizing after the mode of "Packing".

On Fig presents the device with all subsequent sets of pressure after the mode "Dopakovka" (in the final "closed" position).

Figure 9 shows a sleeve;

Figure 10 - sleeve in figure 9 (top view).

Figure 1-10 adopted the following notation:

1 - pipe body (packer case);

2 - cork;

3 - piston-spool;

4 - spring;

5 - sleeve;

6 - axis of the sleeve 5;

7 - the first pin;

8 - the second pin;

9 - the third pin;

10 - the fourth pin;

11 - ring with curly grooves (step limiter for moving the piston-spool 3);

12 - the first curly grooves;

13 - second curly grooves;

14 - hole (for communication of the cylindrical cavity with the sealing element);

15 - hole (for communication of the cylindrical cavity with the axial channel of the packer);

16 - emphasis;

17 - the first sealing ring;

18 - the second sealing ring.

The device (figure 1) includes a housing-pipe 1 with a cylindrical cavity made in its wall for filling with liquid, a tube 2 located in the cylindrical cavity, a piston-spool 3 with a spring 4, on the axis of which a sleeve 5 is placed, having an axis 6 and offset relative to each other, the first and second pins 7, 8 and the third and fourth pins 9, 10 offset from each other, between which a single ring 11 is installed with the first and second curly grooves 12, 13 for stepwise restricting the movement of the piston-spool 3.

The cylindrical cavity of the housing-pipe 1 has a message through the hole 14 with the sealing element and through the hole 15 with the axial channel of the packer.

The piston-spool 3 is placed in a cylindrical cavity between these holes 14, 15 with the possibility of their communication with each other during axial movement.

The spring 4 is installed in the plug 2 and is separated from the sleeve 5 by the emphasis 16.

The first, second, third and fourth pins 7, 8, 9, 10 (Fig. 9) are mounted on the side surface of the sleeve 5 with the possibility of interaction with the corresponding first and second curly grooves 12, 13 so that the axis of the first, third pins 7, 9 and the axes of the second, fourth pins 8, 10 are located on the corresponding diametrical lines of the sleeve 5. The axes of the first and second pins 7, 8 and the axes of the third and fourth pins 9, 10 in a horizontal projection are respectively at an angle (β) from 7 to 25 degrees relative to axis 6 of sleeve 5, i.e. these pins 7, 8 and pins 9, 10 are offset (figure 10) relative to each other by an angle (β) from 7 to 25 degrees to the axis 6 of the sleeve 5.

The necessary tightness of the joints in the device is provided by the first and second o-rings 17, 18.

The device operates as follows. After lowering the packer with a device for supplying fluid to the sealing element on the casing in a predetermined interval of the well and releasing the hole 15 from its overlap, excessive pressure is created in the axial channel of the body-pipe 1, for example 2 MPa (figure 2), and liquid from the inner cavity the casing string through the hole 15, compressing the spring 4 (for example, 1.5 MPa is used to compress the spring), moves the piston-spool 3 with the sleeve 5 in the axial direction. The second and fourth pins 8, 10 exit the second curly grooves 13 rings 11 of FIG. urn grooves (step limiter of axial displacements), and the first and third pins 7, 9, interacting with the first curly grooves 12, rotate the sleeve 5, thereby installing the second and fourth pins 8, 10 opposite the following corresponding second curly grooves 13. When removing excess the pressure in the inner cavity of the casing string, the piston-spool 3 with the sleeve 5 under the action of the compressed spring 4 moves in the opposite direction. The first and third pins 7, 9 of the sleeve 5 come out of the corresponding first curly grooves 12, and the second and fourth pins 8, 10, interacting with the corresponding second curly grooves 13, rotate the sleeve 5, thereby installing the first and third pins 7, 9 opposite the corresponding first curly grooves 12 (figure 3).

When you re-set the pressure in the inner cavity of the casing string (mode "Packing") (figure 4), the liquid from the hole 15 enters the cylindrical cavity of the valve mechanism. While the piston-spool 3 compresses the spring 4, the first and third pins 7, 9 come out of the first curly grooves 12, and the second and fourth pins 8, 10 enter the second curly grooves 13 of increased length, while simultaneously turning the sleeve 5 at a predetermined angle . The first sealing ring 17 extends beyond the bore, so that the liquid from the inner cavity of the casing string is able, through the opening 15, flowing around the first sealing ring 17, to fill the cavity under the sealing element with deformation of the latter.

When the pressure is released in the inner cavity of the casing string after the completion of the "Packing" mode (Fig. 5), the piston-spool 3 under the action of an expanding spring 4 returns to its original position. In this case, the second and fourth pins 8, 10 come out of the second curly grooves 13, and the first and third pins 7, 9 enter the first curly grooves 12, while simultaneously turning the sleeve 5 through a predetermined angle.

At the next set of pressure in the inner cavity of the casing string ("Dupacking" mode) (Fig.6), fluid from the hole 15 again enters the cylindrical cavity of the valve mechanism. In this case, the piston-spool 3 again compresses the spring 4, the first and third pins 7, 9 come out of the first curly grooves 12, and the second and fourth pins 8, 10 are in the second row of the second curly grooves 13 of increased length, while turning the sleeve 5 at a given angle. The first o-ring 17 again extends beyond the bore, so that liquid from the aperture 15, flowing around the first o-ring 17, again enters the cavity under the o-ring, compensating for the partial pressure drop under the o-ring, caused by stretching of the rubber layer.

When the pressure is released in the inner cavity of the casing string after the completion of the “Additional Packing” mode (Fig. 7), the piston-spool 3 is returned to its original position by the force of an expanding spring 4. In this case, the second and fourth pins 8, 10 come out of the second curly grooves 13, and the first and third pins 7, 9 enter the first curly grooves 12, while simultaneously turning the sleeve 5 through a predetermined angle.

With all subsequent sets of pressure (Fig. 8), the liquid from the opening 15 is no longer able to enter the cylindrical cavity of the valve assembly, since the first sealing ring 17 never again extends beyond the limits of the bore. In this case, the piston-spool 3 compresses the spring 4, the first and third pins 7, 9 exit the first curly grooves 12, and the second and fourth pins 8, 10 do not enter the second curly grooves 13, the sleeve 5 does not rotate. The first o-ring 17 does not extend beyond the bore, thereby preserving the tightness between the insulated cavities.

The design of the proposed device withstands three times greater pressure drop (up to 25 MPa) than the prototype. In addition, the reliability of the entire product as a whole increases significantly due to the arrangement of the valve mechanism (bushings 5 with restrictive first, second, third, fourth pins 7, 8, 9, 10, rings 11 with curly grooves, springs 4) in a separate cylindrical cavity isolated from the axial channel of the packer. Thus, the possibility of ingress of small abrasive particles and jamming of the device until the completion of the packing process is excluded. The device has a wider field of application, including in packers for isolation of productive formations having large reservoir pressures.

Claims (4)

1. A device for actuating the sealing element of the packer, comprising a housing-pipe with a cylindrical cavity made in its wall for filling with liquid and two holes for the latter to communicate with the sealing element, a tube located in the cylindrical cavity, a piston-spool with a spring, on the axis of which a sleeve is placed with first and second pins displaced relative to each other, between which a ring with curly grooves is installed to limit the movement of the piston-spool placed in the cylinder dical cavity between these holes with the possibility of their communication with each other during axial movement of it, an emphasis located on the piston-spool between the sleeve and the spring, and O-rings, characterized in that the ring with shaped grooves is made integral, the sleeve is provided with a third offset relative to each other and fourth pins mounted on the sleeve in such a way that the axes of the first, third pins and the axis of the second, fourth pins are located along the respective diametrical lines of the sleeve, and the spring is then The spool is mounted in a plug. 2. The device according to claim 1, characterized in that the first, second pins and the third, fourth pins, respectively, are offset relative to each other by an angle from 7 ° to 25 ° to the axis of the sleeve. 3. The device according to claim 1, characterized in that the first, third pins and the second, fourth pins are placed symmetrically with respect to the corresponding diametrical lines of the sleeve. 4. The device according to claim 1, characterized in that the first, second, third and fourth pins are made with a diameter of from 0.8 mm to 3.2 mm

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