RU2280759C2 - Well cleaning device - Google Patents

Abstract

FIELD: oil industry, particularly devices to operate wells complicated with powder material precipitations on well face and in bottomhole formation zone.

SUBSTANCE: device comprises serially arranged flow string, discharge valve, accumulation container and cylinder with piston, as well as check valve and liner. The device also has pushing tube having upper part located in the cylinder so that the tube may cooperate with the piston, and lower part connected to the liner. Accumulation vessel is connected with the cylinder. In initial state the piston is fixed in the cylinder by means of fastening members, which may be sheared under the action of flow string. Pusher tube travel limiter is installed in the cylinder.

EFFECT: increased efficiency of precipitation removal.

2 cl, 1 dwg

Description

The claimed technical solution relates to a means of cleaning wells from solid bulk materials (mechanical impurities): sand, clay, scale, small foreign objects, pieces of metal and cable. The device can be used in the oil industry for wells whose operation is complicated by the accumulation of heavy heavy sediments at the bottom.

During well operation and repair work, accumulation of mechanical impurities at the bottom and in the bottomhole formation zone occurs. This leads to overlapping filtration holes through which oil enters the well, reducing well productivity and reducing oil production. There are various methods and devices for removing mechanical impurities.

A device for cleaning wells is known, comprising a string of tubing, a drain valve, a storage container and a cylinder with a hollow piston, a hollow piston connected to the storage container and ring seals and side openings for the passage of fluid and installed in the cylinder on the middle elements, and the cylinder is connected to a shank having a check valve (Patent RU No. 2160825, FIG. 2, IPC E 21 B 37/00, publ. 20.12.2000).

The known device is ineffective when used with the aim of destroying and lifting densely pressed deposits and small metal objects due to the low throughput gap between the shank and the piston and holes in the piston.

The technical result of the proposed device is to increase the efficiency of the known device for removing densely compressed deposits and heavy particles from the bottom of the well and the bottomhole formation zone.

The technical result is achieved by the fact that the device for cleaning wells, containing sequentially installed tubing string (tubing), drain valve, storage container and cylinder with a piston, as well as a check valve and liner, according to the invention is characterized in that the piston in the source state is fixed in the cylinder using fasteners with the possibility of cutting them under the influence of the weight of the tubing, the device is equipped with a push rod, the upper part of which is located in the cylinder the piston into the storage container and the fluid flow through the cavity of the pusher pipe into it, the lower part of the pusher pipe is connected to the shank, and the storage container is connected to the cylinder in which the stroke limiter of the pusher pipe is installed.

In addition, o-rings can be installed on the piston.

The drawing shows a diagram of the proposed device.

A device for cleaning a well comprises a tubing string 1 connected to a storage container 2 of mechanical impurities. A drain valve 3 is installed between them. In the cylinder 4, rigidly connected with the storage container, a piston 6 (plunger) is mounted on the fixing bolts 5. The dimensions (diameter) and the number of bolts 5 are calculated in advance based on the estimated weight of the tubing string 1 and the back pressure in the well. Between the inner surface of the cylinder 4 and the outer surface of the piston 6, rubber sealing rings 7 are installed at the location of the latter, hermetically separating the inner cavity of the container 2 from the inner cavity of the push rod 8, the upper part of which is placed in the cylinder 4, and the lower one is rigidly connected to the shank 9 ( “Feather”) through the check valve 10. A stroke limiter 11 is fixed on the cylinder 4, and a stop 12 on the pushrod pipe 9.

The device operates as follows.

When the device moves downward, under the influence of the weight of the tubing string 1, the fastening bolts 5 and piston 6 are cut off due to the pressure difference between the well and the internal cavity of the tubing is pushed into the container 2 by the pusher pipe 8.

The pusher pipe 8, rigidly connected with the shank 9, resting on the bottom, during the movement of the tubing remains stationary. The container 2 with the cylinder 4 moves down to the stop of the restrictive stroke 11 at the stop 12 on the pipe-pusher 8.

Through the cavity of the pusher tube 8, the fluid flow, together with the heavy particles, rushes into the container 2. In the process of pressure equalization, the check valve 10 closes, and the device, together with the trapped mechanical impurities, rises to the surface. To facilitate lifting, the drain valve 3 is first opened, and fluid from the tubing flows into the well.

This device can also be effectively used in production and injection wells for cleaning of heavy compressed mechanical impurities and the bottom hole of the formation, due to the large throughput of the pusher pipe, which allows you to capture large volumes of fluid with a large number of heavy particles and throw them directly into the storage container.

Claims (2)

1. A device for cleaning wells, containing sequentially installed tubing string (tubing), a drain valve, a storage container and a cylinder with a piston, as well as a check valve and a liner, characterized in that the piston in the initial state is fixed in the cylinder with shear elements with the possibility of cutting them under the influence of the weight of the tubing, the device is equipped with a pusher pipe, the upper part of which is located in the cylinder with the possibility of pushing the piston into the storage container and the output of a fluid stream Erez cavity pusher tube, the lower part of the pipe is connected to the pusher shaft and a container connected to the drive cylinder, in which a stroke limiter tube-pusher. 2. The device according to claim 1, characterized in that the sealing rings are installed on the piston.