SU540029A1 - Device for cleaning the well bottom zone - Google Patents

Description

one

The invention relates to the exploitation and development of wells, in particular to the design of devices designed to clean the wellbore bottomhole zone.

The known device for cleaning the well bottom zone, consisting of tubes concentrically placed relative to each other, a packer, a cylinder with windows and a piston with a spring-loaded piston with channels connected to the inner tube space located in the cylinder.

However, this device is not suitable for repeated use without lifting it to the surface.

The purpose of the invention is to ensure the multiple operation of the device without lifting it to the surface.

This is achieved by the fact that the inner pipe string is equipped with a movable hollow rod with a valve mounted to interact with the piston, which, in turn, is provided with an additional channel connected to the annular space.

The drawing schematically shows the proposed device.

It consists of columns of the outer row of pipes I and internal -2 that are concentric with respect to each other. A cylinder 3 with windows 4 and 5 is attached to the outer row of pipes, inside which is placed a spring-loaded

from the spring side G, a piston 7 with channels 8 and 9. A shank 10 is attached to the cylinder 3 to stop the packer 11 against the bottom of the well. The inner row of pipes 2 in the lower part is equipped with a movable hollow rod 12 with a valve 13 and centering lights 14. In order to fit the rod 12 in the socket 15 of the piston 7, its lower part is made tapered. Stock mobility limited

two thrust rings 16 and 17.

The operation of the device is as follows.

Under the action of a part of the weight of the empty tubes of the inner row and 2, the hollow rod 12, which is planted in the tapered seat 15 of the piston 7, overcomes the resistance of the spring 6, moves the piston down. When the cylinder reaches the inner row of pipes 2 of the upper cover of the cylinder 3, the channels 9 in the piston 7 will coincide with the windows

4 in cylinder 3. This will result in a complete depression of the pressure on the reservoir, as a result of which the formation fluid rushes through these windows 4 in the cylinder 3 and channels 9 in the piston 7 into the empty cavity of the pipes 2. When the required level is reached, a second depression pressure on the reservoir. This is achieved as follows.

On the ball valve 13 an additional pressure is given from the surface, under the action of which the clanan closes and the piston 7