RU33600U1 - Device for cleaning wells from sand plugs - Google Patents

Description

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Device for cleaning a well from a plug

The proposal relates to the oil and gas industry and can be used when cleaning wells from unoccupied traffic jams.

A device for cleaning wells from sand plugs is known, consisting of a fixed body on which a movable cup is mounted rigidly connected to a turbine. A sleeve spring-loaded with an external spring is installed on the body. It consists of a lower casing and an upper outer cup. In the upper part of the fixed housing there is a rectangular annular groove in which a split spring ring is installed. Trapezoidal grooves with mutually opposite taper angles 1 are made in the upper part of the outer cup.

The disadvantage of this device is the design complexity, due to the presence of a large number of moving units and parts, which in the process of working in contact with the slit (a mixture of working fluid and sand) reduce the efficiency of its use.

Closest to the technical nature of the proposed device is a device for cleaning wells from sand plugs, containing a circulation coupling connected to a housing in which there are radial holes. A special coupling is screwed onto the upper end of the housing. On the outer surface of the housing, a rubber self-sealing cuff is installed, which is held by a spacer ring and

Device object

MPK7E 21 at 37/00, 21/00

clamping nut. In the middle of the circulation sleeve there is a socket in the thread of which

the lower end of the inner pipe is screwed in, and its upper end is sealed from the outside with a stuffing box packing and packing follower, which excludes the possibility of the passage of the working fluid through the connection of the pipe with a special coupling. Significant disadvantages of the device are:

-the complexity of the design, due to the large number of nodes and parts;

 -complicated intensive removal of sludge due to the different areas of the internal cross sections of the inner pipe and flushing pipes;

- damage to the self-sealing cuff due to friction against the walls of the well during its descent to the sand plug, which reduces the cleaning efficiency.

The objective of the utility model is to develop a device with a simpler design that can improve the efficiency of cleaning a well from sandy plugs by optimizing the erosion of the plugs with intensive removal of slurry and reliable sealing of annular space due to the integrity of the self-sealing cuff during descent into the well.

This problem is solved by the proposed device containing a nozzle concentrically mounted in a hollow body on which is located a self-sealing cuff with a clamping nut and a tip.

New is that it is equipped with a hollow cylindrical nozzle connected to the lower part of the hollow body; equipped with an installation sleeve on which the self-sealing sleeve is located, and a clamping nut mounted on the outer surface of the hollow body, in addition, the hollow body has the ability to axially move a certain length / relative to the installation sleeve, which allows you to create a limited load when pressing the self-sealing sleeve; equipped with a tip having longitudinal grooves on the outer surface and installed in the upper part of the hollow body; equipped with four taps.

2 located radially in a hollow housing, and communicating the internal space

a nozzle plugged from the bottom with a sand plug formation zone, and the ratio of the structural dimensions of these elements is determined by the following relationship:

(1)

where S is the internal cross-sectional area of the pipe, m;

Si is the internal cross-sectional area of one branch, m

Also new is the fact that the inner diameter of the nozzle is equal to the inner diameter of the flushing tubes.

Also new is the fact that the device is equipped with a limiter rigidly connected to the installation sleeve using rods that determine the optimal distance for effective erosion of the sand plug L 0.15 - 0.25 m, selected experimentally.

Also new is the fact that the device is equipped with rigid centralizers installed in the lower part of the installation nut, the outer diameter of which is larger than the outer diameter of the self-sealing cuff.

In FIG. 1 shows the proposed device.

It consists of a pipe 1, muffled from the bottom and concentrically located in the hollow body 2 onto the lower end of which a hollow cylindrical nozzle 3 is screwed.

Above the ledge 4 of the hollow body 2, an installation sleeve 5 is located on which a self-sealing sleeve 6 is mounted, fixed on it with a clamping nut 7. The installation sleeve 5 is equipped with rigid centralizers 8. The lower part of the installation sleeve 5 is rigidly connected to the limiter 9 by means of rods 10. The hollow body 2 and the installation sleeve 5 are interconnected by a shear element 11. A tip 12 having longitudinal channels on the outer surface 13 is screwed onto the upper part of the hollow body 2. Four radially arranged bends 14 communicate internally The lower cavity of the pipe 1 with the zone of formation of the sand plug 15.

3 Moreover, the outer diameters of the rigid centralizers di are slightly larger than the outer

the diameter of the da self-sealing cuff, therefore, during the descent, it is not damaged, and during the erosion of the sand cork, it provides reliable sealing of the annular space.

For the effective operation of the device, it is necessary to observe the ratio of the structural dimensions of the elements, which is determined by the dependence (1).

The device operates as follows.

It is connected using a sleeve 16 to the column of washing pipes 17 (for example, a flexible pipe) and lowered into the well 18 to the zone of formation of the sand plug 15.

The wellhead is sealed with an oil seal 19, after which the wash pipe string begins to be discharged onto a sand cork, as a result of which the sheared element 11 is cut off, as a result, parts 5,6,7,8,9,10 remain stationary, and parts 1, 2, 3, 4, 12, 14, 16 together with the column of flushing pipes 17 are lowered down a certain length /, until the tip 12, having spread the collar of the self-sealing cuff 6, reliably presses it against the wall of the well 18 with a certain force limited by the length of the axial displacement /.

After that, the working fluid (for example, industrial water with surfactants) is supplied under a certain pressure to the annulus of the well, which enters the longitudinal grooves of the tip 12, additionally hydraulically pressing the collar of the self-sealing cuff against the wall of the well 18. In parallel, the working fluid enters the annular the space formed by the pipe 1 and the hollow body 2, and through the hollow cylindrical nozzle 3, the jet of the working fluid rushes into the sand formation zone cork 15, eroding it. A mixture of washed sand cork and working fluid

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4 gets through bends 14 into the pipe 1 p rises along the column of washing pipes to

surface.

As the sand plug eroses, the wash pipe string 17 descends into the well to the height of the sand plug, and in the process of erosion and removal of sludge to the surface, it is always in an unloaded state on it.

. The completion of the well cleaning process is indicated by a decrease in the load on the sand plug, which is controlled by the weight indicator, after which the stuffing box 19 is removed from the wellhead, the flushing pipe string 17 is lifted, as a result of which the self-sealing cuff 6 moves away from the well walls, and the flushing string is fully lifted pipes with the device to the surface.

The proposed device is simpler in design, and due to reliable closure of annular space by preliminary mechanical control of the pressing force of the self-sealing cuff to the well wall during the erosion of the sand plug and the high rate of upward flow of sludge in the washing pipes, achieved due to the same internal cross-sectional area of the nozzle and the washing pipe , as well as the optimally selected distance L between the nozzle and the sand cork during its erosion, allow o to increase the efficiency of well cleaning, which means to reduce the cost of work and save significant material resources.

Information used

1.Analog. A.S. No. 829877, MKI E21 B37 / 00 MKI E21 21 / 00.1981.

2. The prototype. Amirov A.D., Ovnatanov S.T., Yashchin A.S. Overhaul of oil and gas wells. M., Pedra, 1975 p. 214-216.

5

Claims (4)

1. A device for cleaning a well from a sand plug, containing a nozzle concentrically mounted in a hollow body on which a self-sealing sleeve is located, characterized in that it is provided with a hollow cylindrical nozzle connected to the lower part of the hollow body, equipped with an installation sleeve on which the self-sealing is located cuff, and a clamping nut mounted on the outer surface of the hollow body, in addition, the hollow body has the possibility of axial movement by a certain length l relative to the mouth the sleeve, which allows you to create a limited load when pressing the self-sealing cuff to the walls of the well, is equipped with a tip having longitudinal grooves on the outer surface and installed in the upper part of the hollow body, is equipped with four bends located radially in the hollow body and communicating the inner space of the pipe muffled from below the zone of formation of sand cork, and the ratio of the structural dimensions of these elements is determined by the following relationship: S≤4S ₁ , where S is the internal cross-sectional area of the pipe, m ² ; S ₁ - the internal cross-sectional area of one branch, m ² . 2. The device according to claim 1, characterized in that the inner diameter of the nozzle is equal to the inner diameter of the washing pipes. 3. The device according to claim 1, characterized in that it is equipped with a limiter rigidly connected to the installation sleeve using rods that determine the optimal distance for the effective erosion of the sand plug L = 0.15 ÷ 0.25 m 4. The device according to claim 1, characterized in that it is equipped with rigid centralizers installed in the lower part of the installation nut, the outer diameter of which is larger than the outer diameter of the self-sealing cuff.