RU2739178C1 - Mechanical impurities cleaning system for production wells with application of spiral-slot filter - Google Patents

Abstract

FIELD: mining.

SUBSTANCE: invention relates to cleaning impurities from production wells. Proposed system comprises casing string with motor and pump, spiral-slotted filter and perforated tube. At the same time casing string in lower part contains packer. With the help of this packer casing string is tightly connected to safety device of automatic coupler-catcher. This filter is installed inside perforated pipe. Upper part of the filter is blind and is tightly fixed in the automatic coupler-catcher. Lower part of the pipe is perforated. Besides, the filter from the lower end face is covered with an impermeable cover.

EFFECT: technical result is improved wear resistance and durability of cleaning system, as well as simplification of this system.

6 cl, 1 dwg

Description

The proposed technical solution relates to filtration systems for capturing mechanical impurities contained in the extracted solution and their precipitation in the storage tank during the extraction of uranium-containing solutions.

Known spirally slotted filter, see RF patent No. 2378494 from 10.01.2010. This slotted filter with a wire filtering element contains a perforated pipe with nipple and coupling parts, concentrically to which the filtering element is made of spiral wound wire connected to longitudinal wire stringers. In this case, the wire in the spiral is laid turn to turn, and, at least on one of the contacting sides of the wire, a notch is made to provide a filter gap, while the notch on the wire is tangential or intersecting. The disadvantages of this solution are the complexity of cleaning and disassembly and low durability.

The closest technical solution is a downhole pumping filter, see RF patent No. 2302514 dated 10.07.2007. This filter contains a perforated pipe and a filtering metal mesh, covering the outer surface of the perforated pipe, and is made of two main parts: filtering and connecting, which are fixed to each other by means of a coupling, the filtering part is a perforated pipe with slotted holes 0.04-0 , 05 and 1.5-2.0 in length from its inner diameter, and the connecting part is a perforated pipe with holes 0.2-0.22 in diameter from its outer diameter and occupying an area of 20-30% of the entire surface of the connecting part, a bushing with a threaded joint is welded onto the pipe body of the connecting part for installing rubber sealing rings, the outer diameter of which is 3-5 mm larger than the inner diameter of the well, with gaskets clamped with a round nut and fixed with a lock nut. The disadvantage of this system is the lack of reliability and maintainability.

The proposed solution can eliminate the above disadvantages.

The proposed system allows you to clean the solution from mechanical impurities, precipitating them in the accumulator and preventing the ingress of solid inclusions into the working bodies of the submersible pumping unit, thereby eliminating accelerated wear of the pump and its clogging (stopping the supply).

Fundamental improvements from existing analogues:

• The unit is operated in corrosive environments, which forces the use of corrosion-resistant construction materials;

• The system is mounted without the use of fraction separators and retaining units such as an anchor or packer;

• The system is easily removed and cleaned due to the built-in automatic coupler elements;

• The filter itself is very durable;

• Allows autonomous, independent mounting from a submersible pumping unit;

• Allows you to extract and dispose of mechanical impurities, thereby cleaning the productive formation and extending the operational periods between repair and restoration works.

• To exclude the filling of the casing "liner" with mechanical impurities, it can additionally be equipped with a limiter, which can also be easily removed by means of an automatic coupler.

EFFECT: increased wear resistance and durability, simplified system cleaning.

The technical result is achieved by the fact that the system for cleaning from mechanical impurities for production wells using a spiral-slotted filter includes: a casing with an electric motor and a pump installed in it, a spiral-slotted filter and a perforated pipe. In this case, the casing string in the lower part contains a packer, by means of which it is hermetically connected to a spiral-slotted filter-automatic coupler, and the spiral-slotted filter is installed inside the pipe, the lower part of which is made perforated.

Also, the spiral-slotted filter should preferably include a centralizer, centering it in the pipe, and the spiral-slotted filter at the bottom end is closed with an impermeable cover.

In addition, the spiral slot filter may include an extension and / or a cone weighting agent.

In the lower part of the pipe, a restrictor glass can be installed, which is a rod installed in the perforated part of the pipe. In this case, as a rule, the lower perforated part of the pipe corresponds to the productive formation of the produced fluid.

The upper part of the pipe is made blind and hermetically fixed in the automatic coupler catcher.

The pump through pipes made of low pressure polyethylene delivers the cleaned liquid to the surface.

The suggested solution is illustrated by the figure:

FIG. - General scheme of the proposed cleaning system from mechanical impurities for production wells using a spiral slotted filter.

In the figure, reference numerals designate the following reference numerals.

1 - productive formation;

2 - perforated part of the pipe,

3 - casing string;

4 - spiral slotted filter;

5 - conical weighting agent;

6 - centralizer;

7 - glass-limiter;

8 - pump;

9 - electric motor;

10 - catcher-automatic coupler;

11 - packer.

The operation of the proposed device shown in the figure is as follows:

The fluid or solution comes from the reservoir (item 1) through the perforated pipe (item 2) into the casing body. The diameter and number of holes are calculated based on the well rate and the size of the drainage pebbles. At the junction of the casing diameters on the flange, which ensures tight separation using the casing packer (item 11) (item 3), a spiral slotted filter (item 4) is mounted. with automatic coupler safety device (pos. 10). The filter is made of AISI316L type corrosion-resistant steel or its analogs. It can be additionally equipped with an extension cord made of low-pressure polyethylene HDPE and, if necessary, with a conical weighting agent (item 5) and a centralizer (item 6). Liquid with inclusions of mechanical impurities lifted by a corrosion-resistant pump, for example, Grundfos (item 8) assembled with an electric motor drive (item 9), enters the filter elements, where the liquid is separated from mechanical impurities, and then flows into the discharge pipe ... In this case, solid particles settle and are retained on the slotted screen, partially fall into the "liner" of the casing string. To exclude clogging of deposits by mechanical particles of the "liner" of the casing, which lies below the level of the productive formation and to maintain a constant velocity of the fluid (solution) movement, it is allowed to equip with a restrictor glass (item 7). The purified liquid is pumped (item 8) through pipes made of low-pressure polyethylene HDPE to the surface. When the liquid supply is interrupted, due to clogging of the filter element slots by mechanical impurities, the production process stops and repair and restoration work is carried out.

Claims (6)

1. A system for purification from mechanical impurities for production wells using a spiral-slotted filter, including: a casing with an electric motor and a pump installed in it, a spiral-slotted filter and a perforated pipe, characterized in that the casing in the lower part contains a packer, by of which it is hermetically connected to the automatic-coupler safety device of the spiral-slotted filter, while the spiral-slotted filter is installed inside the perforated pipe, the upper part of which is made deaf and hermetically fixed in the automatic coupler safety device, and the lower part of the pipe is made perforated, in addition, the filter from the lower the end is closed with an impermeable lid. 2. The system of claim. 1, characterized in that the spiral-slotted filter includes a centralizer for centering it in the pipe. 3. The system according to any one of paragraphs. 1, 2, characterized in that the spiral-slotted filter includes an extension and / or a cone weighting agent. 4. The system according to claim. 1, characterized in that in the lower part of the pipe there is a nozzle-limiter, which is a rod installed in the perforated part of the pipe. 5. The system of claim. 1, characterized in that the lower perforated part of the pipe corresponds to the productive formation of the produced fluid. 6. The system of claim. 1, characterized in that the pump through pipes made of low pressure polyethylene is provided with the ability to supply the purified liquid to the surface.

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