RU2236560C2 - Method for oil extraction - Google Patents

Abstract

FIELD: oil extractive industry.

SUBSTANCE: method includes lowering into operational column of well of tubing string with packer and washing valve fixed in its lower portion. Packer is placed in lower portion of tubing string, above operational oil bed, and washing valve - above the packer. Then packer is switched into operating mode with overlapping of ring-shaped space between tubing string and operational column for separating operational oil bed. Well is taken into operation for oil extraction. In case of influx of foreign water into the well, maintenance operations are performed. Interval of non-sealed portion of operational column is determined. Tubing string is lowered. Washing valve is placed above non-sealed zone, and packer - below that zone for separating operating oil bed from zone of foreign water influx in the well.

EFFECT: excluded performing of long costly maintenance operations.

2 cl, 1 dwg

Description

The proposal relates to the oil industry and can be used in oil wells with violations of the tightness of the production string or to transfer the well to the underlying oil reservoir.

During the exploitation of oil fields, especially old ones, cases of leakage in the production string as a result of corrosion are not uncommon. After the development of oil reserves or the premature flooding of an operating oil class, it becomes necessary to transfer the well to the underlying formation. In both cases, repair and insulation work is required.

There are various methods for the restoration of a destroyed column and the separation of layers, including metal plaster and plugging agents.

A known method of repairing wells by lowering into the well a string of tubing with a packer (SU 1514906 A1, E 21 B 33/12, 10/15/1989.).

Using this method is ineffective and durable due to high depressions in the production casing.

Closest to the proposed one is a method of oil production, including the descent into the production casing of a well of a string of tubing with a packer and a flush valve fixed in its lower part so that the packer is placed above the working oil reservoir, and the flush valve above the packer, putting the packer in working condition with overlapping annular space between the tubing string and the production string to separate the working oil reservoir and launching the well into oil production and (RU 2081303 C1, E 21 B 43/00, 06/10/1997.).

However, the known method of oil production does not provide for the possibility of reducing the flow of foreign fluid into the well during depressurization of the production string.

The technical result of the invention is the ability to reduce the flow of foreign fluid into the well while continuing to produce oil without lengthy expensive repairs.

The technical result is achieved by the fact that the method of oil production includes lowering into the production casing a well of tubing string with a packer and a flush valve fixed in its lower part so that the packer is placed above the working oil reservoir, and the flush valve is above the packer, putting the packer in working condition with overlapping the annular space between the tubing string and the production string to separate the working oil reservoir and putting the well into operation for oil production, In this case, if foreign water enters the well, repair work is carried out, for which the leakage interval of the production string is determined, the tubing is lowered into the production string so that the flush valve is placed above the leakage zone, and the packer is below the leakage zone to separate the working oil formation from the zone of entry into the well of extraneous water.

In addition, after the said annular space is closed by the packer, a sealing liquid is introduced into it above the packer to close the leakage interval of the production string.

The drawing shows an example implementation of the method.

A device for implementing the method consists of a tubing string 1, a packer 2, a flushing valve 3 and a sealing liquid 4. A packer 2 is placed below the foreign water supply zone, but above the working formation 5. The flushing valve 3, located above the foreign water supply zone, It is used for technological flushing and killing of wells during repair work. Packer 2 and flush valve 3 are attached to the tubing 1.

The method of oil production is as follows.

A tubing string 1 with a packer 2 and a flushing valve 3 mounted on it is lowered into the production casing 6 of the well. The packer 2 is placed above the working oil reservoir 5. The packer 2 is put into operation, blocking the annular space between the tubing string 1 and production casing 6. When in a foreign water well by known methods, determine the leakage interval of the production string 6. To carry out repair work, the tubing 1 is lowered into the well so that the packer 2 is placed t below the leakage zone, but above the working oil reservoir 5, and the flushing valve 3 is above the leakage zone. Packer 2 is put into operation - it expands and overlaps the annular space between the compressor pipes 1 and production casing 6. In this case, the oil reservoir 5 is separated from the zone of entry of foreign fluid into the well. Above the packer 2, the annular space between the tubing 1 and the production casing 6 can be additionally filled with sealing liquid 4, covering the leakage interval. In this case, the flow of foreign fluid into the well will be significantly reduced. The well, depending on the method of operation, is launched into operation by a submersible pump or by swabbing.

Claims (2)

1. A method of oil production, including the descent into the production casing of a well of a string of tubing with a packer and a flush valve fixed in its lower part so that the packer is placed above the working oil reservoir and the flush valve is above the packer, transferring the packer to working the condition with the overlap of the annular space between the tubing string and the production string for separating the working oil reservoir and launching the well into oil production, characterized in that if foreign water enters the well, repair work is carried out, for which the leakage interval of the production string is determined, the tubing string is lowered into the production string of the well in such a way that the flush valve is placed above the leakage zone and the packer is below the leakage zone to separate the worker oil reservoir from the zone of entry into the well of extraneous water. 2. The method according to claim 1, characterized in that after the packer closes the annular space between the tubing string and the production string, sealing liquid is introduced into the said annular space of the well above the packer to close the leakage interval of the production string.