RU2280760C1 - Filtering well construction method - Google Patents

Abstract

FIELD: mining, particularly methods or apparatus for obtaining oil, gas, water and other materials from wells.

SUBSTANCE: method involves lowering production and filtering strings provided with circulation valve, flushing channels, shear plug and sealing bush in well; flushing the well; washing-in gravel filler; closing flushing channels with sealing bush provided with shear plug and used as cementing plug. Production string has smooth inner surface. Filtering string is connected to production string during filtering column lowering in well. After gravel filler washing-in the well is cemented. Cement grout is forced by means of sealing bush with shear plug up to shear plug landing onto thrust part of circulation valve and flushing channel closing. Then the shear plugs of sealing bush and circulation valve are sheared. Well flushing, gravel washing-in and cement grout supply are carried out via flushing channels of circulation valve.

EFFECT: increased efficiency due to possibility to perform simultaneously several operations and reduced well diameter.

2 cl, 1 ex, 1 dwg

Description

The invention relates to the field of mining, in particular to wells for producing or injecting a fluid, and can be used when completing a well during drilling, to develop mineral deposits by underground leaching.

A known method of constructing a filter well, including production and filter columns, a flushing pipe with a circulation valve [1].

The known method provides optimal distribution of gravel throughout the prefilter zone of the well, however, the process of packing gravel is provided through the production string, which is possible with sufficiently large diameters of the well.

There is also known a method of constructing a filter well, including drilling, expanding the wellbore, lowering production and filter columns with a circulation valve with flushing channels and a locking sleeve, lowering the injection column with a distribution unit and a locking sleeve control mechanism [2].

The disadvantage of this method is the unreliability of the control mechanism, as well as the failure to ensure the reliability of the processes of gravel washing and cementation with the formation of the reserve and buffer zones of the well.

The closest in technical essence is the method of constructing a filter well, which includes the descent into the expanded part of the wellbore of an operational and filter string with a circulation valve with flushing channels, a shear plug and a locking sleeve [3].

The disadvantage of this method is that the gravel packing is reclaimed through the casing, and the filter string is lowered on the tubing.

The objective of the present invention is to increase the efficiency of the method by combining technological operations and reducing the diameter of the well.

The problem is solved in that in the method of constructing a filter well, which includes running production and filter columns with a circulation valve, flushing channels, shear plug and shut-off sleeve, flushing a well, washing gravel packing and blocking the washing channels with a shut-off sleeve, the filter column is lowered onto the production string , washing the well, washing the gravel pack through the production casing, washing channels, closing the washing channels after feeding etnogo volume of cement slurry into the production tubing, and the plug sleeve is provided with a shear cementing plug and slidably mounted in the production tubing above the cement mortar.

In addition, the production casing is made with a smooth inner surface and is provided with expansion rings at the joints of the casing joints.

The invention is illustrated in the drawing.

The tool includes a filter column 1, a circulation valve 2, a production column 3.

The circulation valve 2 is made with washing channels 4 and a shear plug 5 located on the protruding thrust part 6 under the washing channels 4.

In the production casing 3, a movable locking sleeve 7 is installed, equipped with a shear plug 8 and made as a cementing plug.

The production casing 3 is made with a smooth inner surface and is equipped with compensation rings 9 at the joints of the joints. The filter column 1 is provided with a sump.

The work of the tool is as follows.

The filter string 1 with a sump 10 is lowered into the well on the production string 3 without shutoff sleeve 7 and installed in the area of the extended part of the wellbore 11.

The well is washed and the gravel is washed through the washing channels 4 of the circulation valve 2. After the gravel has been washed to the optimum level, which is controlled by the pressure gauge on the injection pipeline (not shown in the drawing), cementation is performed. For this purpose, the calculated volume of cement mortar is supplied to the production casing 3, the locking sleeve 7 with the shear plug 8 is introduced into it, and it is pressed through the washing liquid until it is mounted on the thrust part 6 of the circulation valve 2.

In this case, the plugs 5, 8 are cut off, and they are washed into the sump 10, and the washing channels 4 are blocked by the locking sleeve 7.

After flushing, the well is ready for operation.

Technical result:

- improving efficiency by combining technological operations and reducing the diameter of the well.

An example implementation of the method.

The injection test well is to be constructed in a section No. 1 200 m deep with PVC casing ⌀90 / 8 mm and ⌀118 mm filter string equipped with a circulation valve with a shut-off sleeve.

The sequence of work and technological operations is as follows:

- drilling a well to a design depth of 161 mm in diameter;

- conducting geophysical research;

- extension of the productive interval of 20 m of the well, determined according to the logging data: up to 300 mm;

- descent of operational, filter columns;

- flushing the well;

- reclamation of gravel packing through production casing, flushing channels;

- flushing excess gravel packing;

- stopping the flushing for at least 30 minutes to ensure compaction of the gravel pack;

- supply of the estimated volume to the production string for feeding into the annulus of the well through the flushing channels;

- installation of a locking sleeve with a shear cementing plug over the cement mortar and forcing the cement mortar with flushing fluid;

- setting the locking sleeve into the thrust part of the circulation valve, closing the washing channels;

- cutting shear plugs and flushing them into the sump of the filter column;

- conducting airlift washing.

Information sources:

1. RF patent No. 2209943, IPC7, E 21 V 43/04, 08/10/2003.

2. USSR author's certificate No. 1191563, MKI4, E 21 V, 43/08, 11/15/85.

3. RF patent No. 2179628, IPC7, E 21 B 43/04, 02.20.2002.

Claims (2)

1. The method of constructing a filter well, including the descent of production and filter columns with a circulation valve, flushing channels, shear plug and shut-off sleeve, flushing a well, filling gravel packing and blocking the washing channels with a shut-off sleeve, characterized in that the shut-off sleeve is provided with a cut-off plug and as a cement plug, the production casing is performed with a smooth inner surface, the filter casing is lowered on the production casing without a locking sleeve, the last The well of the gravel pack is cemented by the well, for which the cement slurry is pressed through with a shut-off sleeve with a shear plug until it fits onto the stop part of the circulation valve and the washing channels are blocked, then the plugs of the shut-off sleeve and circulation valve are cut, while the well is flushed, the gravel pack is washed and the feed cement mortar is produced through the flushing channels of the circulation valve. 2. The method according to claim 1, characterized in that the production casing is provided with expansion rings at the joints of the connections of the column.