RU2561640C1 - Cleaning device of filter element of well strainer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device includes at least one resonator installed inside a well strainer housing and a pulse source. The well strainer is installed on the lower end of a tubing string. The pulse source is made in the form of a valve-pulsator with a controlled drive and installed in a supply pipeline of washing liquid to the well strainer; the controlled drive is electrically connected to a computer, and pulsation frequency and amplitude sensors are installed after the valve-pulsator. The resonator can be made in the form of a cylindrical housing with a resonant cavity inside it; the cylindrical housing is centred inside the well strainer housing, and on the inner surface of the cylindrical housing of the resonator there are radial holes interconnected with the cavity inside the well strainer.

EFFECT: improving cleaning efficiency; reducing time consumption.

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Description

The invention relates to the oil and gas industry, is specifically intended for cleaning downhole filters.

It is known that well filters become clogged during operation (mudding occurs) and the well flow rate decreases several times.

Methods for cleaning downhole filters can be divided into two groups:

- purification of asphalt-resinous and paraffin hydrate deposits (soluble),

- purification of solid mechanical deposits (sand, clay, dolomite and other insoluble impurities).

In the first case, heat or solvents are used, and in the second, mechanical cleaning or wave (acoustic or hydraulic) action.

A known method and device for cleaning a downhole filter according to the patent of the Russian Federation for invention No. 2332560, IPC ЕВВ 43/00, publ. August 27, 2008

The well filter with the cleaning function is made in the form of a pipe with nipple threaded sections, one of which has a coupling, and with holes on the side of the pipe. The filter element is installed concentrically to the pipe. The filter element is made in the form of two electrodes isolated from each other by means of a grid of non-conductive material. The electrodes are made in the form of a metal mesh and have the ability to connect to a source of electricity. The energy source is placed on the surface or made autonomous, for example in the form of a battery of batteries or an electric generator, and installed inside the downhole filter. The technical result is an increase in well production due to periodic cleaning of the filter element.

The disadvantages of this technical solution are the ability to clean only from tar and paraffin deposits and the need to perform the supply of electricity to a great depth.

The known method and device for cleaning the downhole filter according to the patent of the Russian Federation No. 2382178, IPC ЕВВ 37/08, publ. 09/27/2009

A device for cleaning a downhole filter includes an oscillator installed in the housing, and means for delivering an oscillator to the bottom of the well and supplying electricity. A geophysical cable is used as a means of supplying electricity. The means of delivery of the oscillation generator contains an electric motor with a hydraulic propulsion. The electric motor and oscillation generator are installed in a sealed enclosure. The hydraulic propeller is made with two propellers connected to the electric motor through a transmission mechanism to allow rotation in opposite directions. The technical result is the provision of cleaning the downhole filter and delivery of the cleaning device to the horizontal section of the well, preventing twisting of the geophysical cable due to rotation of the device.

Disadvantages - a complex and expensive delivery device, the presence of a multi-kilometer geophysical cable, the length of the process of cleaning downhole filters.

A known method and device for cleaning a downhole filter (self-cleaning downhole filter) according to the patent of the Russian Federation for invention No. 2338871, IPC ЕВВ 49/08, publ. 01/09/2007

This invention can be used in gas production and filtering water from sand. The self-cleaning well filter is made in the form of a pipe with nipple threaded sections, one of which has a coupling, and with holes on the side surface of the pipe, the filter element concentrically mounted on it. An insulated winding is installed in the filter element, which can be connected to an autonomous energy source, for example, a battery of power elements or an electric generator installed inside the downhole filter. The technical result is to increase the flow rate of the well due to periodic cleaning of the filter.

The disadvantage is the need to periodically change the power elements installed inside the downhole filter due to clutter of its internal section. A device for cleaning a downhole filter according to the patent of the Russian Federation No. 2178724, IPC B01B 29/00, publ. January 27, 2002

The self-cleaning resonant activator filter contains a cylindrical body with covers and nozzles, two emitters, a resonant chamber filled with a liquid medium, an elastic shell and a volume filled with compressed gas and placed between the elastic shell and the housing, a filter element and a tube plate, while the filter element is placed on the tube plate and together they divide the resonance chamber into two parts: the volume into which the liquid mediums to be mixed and cleaned enter, and the volume with the clean medium, while one emit It is located in one volume, and the second emitter is in the second volume. Using the device allows to increase the productivity and duration of continuous operation, as well as to carry out effective mixing and purification of various media in large volumes.

Disadvantages - low efficiency and speed of cleaning caused by the lack of means for tuning the resonant frequency, and the non-optimal arrangement of the resonators.

A device for cleaning a downhole filter according to the USSR AS No. 1171058, IPC B01D 25/00, publ. 08/07/1985, the prototype.

This filter comprises a housing of replaceable blocks with filtering elements and outlet fittings, a thrust plate with an inlet fitting and a pressure plate that presses the blocks against the thrust plate by means of bolts, characterized in that in order to ensure operational reliability it is equipped with a conical reflector mounted on the thrust plate at input fitting, and acoustic resonators, made in the form of a set of parallel plates placed coaxially on the working surfaces of the reflector, and the pressure plate, as well as located along baa side filter element with a grating disc counterbore.

Disadvantages - relatively low cleaning speed of the filter element due to the lack of tune of the resonant frequency and the non-optimal arrangement of the resonators inside the downhole filter.

The objective of the invention is to significantly improve and speed up the cleaning of the downhole filter.

The solution of these problems has been achieved in a device for cleaning the filter element of a downhole filter, containing at least one resonator mounted inside the downhole filter housing and a ripple source, in that the downhole filter is installed at the lower end of the tubing string and the ripple source made in the form of a pulsating valve with a controlled actuator and installed in the pipeline supplying flushing fluid to the downhole filter, the controlled actuator is electrically connected to a computer, and after pulsar lapana installed frequency and amplitude pulsation sensors. The resonator can be made in the form of a cylindrical body with a resonant cavity inside it, the cylindrical body is centered inside the downhole filter housing, and radial holes are made on the inner surface of the cylindrical resonator body communicating with the cavity inside the downhole filter. Resonators can be installed on parts of the downhole filter housing that are free of the filter element. The downhole filter may contain a nipple and a sleeve, and resonators can be made directly near them.

The invention is illustrated in FIG. 1-4, where:

- in FIG. 1 shows a diagram of a device

- in FIG. 2 shows a resonator circuit,

- in FIG. 3 shows a well filter with a single resonator,

- in FIG. 4 shows a well filter with two resonators.

A device for implementing a downhole filter cleaning (Fig. 1-4) is intended for cleaning a downhole filter 1 installed on a tubing string — tubing 2 inside a casing 3 in the region of the oil reservoir 4 located in the soil 5. This device contains a tank 6 for storing flushing fluid, to which a low pressure pipe 7 is connected, having a filter 8 on one side and a pump 9 with a drive 10 on the other. A flushing liquid supply pipe 11 is connected to the outlet of pump 9, at the other end of which flax pulsator valve 12 with a controllable drive 13. Within the well screen 2 in the cavity 14 is set, at least one resonator 15.

A gap 16 is formed between the tubing string 2 and the casing 3. The gap cavity 16 communicates with the annular cavity 17 of the manifold 18. A flush fluid return pipe 19 is connected to the manifold 18, the other end of which is located above or inside the reservoir 6.

The process control system is made in the form of a computer 20 (system unit), to which a monitor 22, a keyboard 23, and a mouse-type manipulator 24 are connected by electrical connections 21.

The controlled drive 13 is connected to the computer 20 by a communication line 25. After the valve-pulsator 12 are connected sensors of the frequency and amplitude of the pulsations, respectively 26 and 27. Sensors 26 and 27 are connected by communication lines 25 to the input to the computer 20.

The resonator 15 has a cylindrical housing 28, a resonant cavity 29 and openings 30 that communicate with the resonant cavity 29 with the cavity 14. The cylindrical housing 28 communicates with the openings 30 with the cavity 14.

Several options for installing the resonator 15 in the downhole filter 1 are possible. FIG. 3 shows the installation of one resonator 15 in the cavity 14 of the downhole filter 1. The downhole filter 1 comprises a housing 31, a sleeve 32 and a nipple 33. Radial holes 34 are made in the housing 31. The radial holes 34 are closed from the outside by a filter element 35. The resonator 15 is installed outside the filter elements 35 (Fig. 3). It is preferable to install two filter elements 15 directly near the coupling 32 and the nipple 33.

DEVICE OPERATION

In operation, the computer 20 is turned on, on which the corresponding software is pre-installed.

In addition, voltage is supplied to the actuator 10 of the pump 9 and the flushing fluid is supplied through the pipeline 10 through the pulsating valve 12 to the cavity 14 of the tubing pipe 2 and then to the downhole filter 1, then through the gap 16 into the cavity 17 of the manifold 18 and then returned through the discharge pipe 19 into the container 6.

The inclusion, frequency and amplitude of the pulsations is controlled by the computer 20. The computer 20 provides a control signal to the actuator 13 to periodically open and close the pulsator valve 12. The pulsator valve 12 creates pressure pulsations in the cavity 15 and inside the downhole filter 1. As a result, solid particles from the external the sides of the downhole filter 1 are separated from the filter element 35 and fall into the gap 18 and then through the return pipe of the washing fluid 19 to the tank 6.

The pulsation amplitude sensors 27 measure the pulsation amplitude and, when it increases, adjust the pulsation frequency of the pulsating valve 12 to a maximum, i.e. before the onset of resonance. The frequency sensor 26 detects a resonant frequency.

The application of the invention will speed up and improve the cleaning of the downhole filter, while minimizing the clutter of the inner section of the downhole filter and not obscuring its filter element.

Claims (4)

1. The device for cleaning the filter element of the well filter, containing at least one resonator mounted inside the housing of the well filter and a ripple source, characterized in that the well filter is installed on the lower end of the tubing string, and the ripple source is made in the form a pulsator valve with a controlled actuator and is installed in the pipeline for supplying flushing fluid to the well filter, a controlled actuator is electrically connected to a computer, and after a pulsating valve Sensors of frequency and amplitude of pulsations. 2. The device for cleaning the filter element of the downhole filter according to claim 1, characterized in that the resonator is made in the form of a cylindrical body with a resonant cavity inside it, the cylindrical body is centered inside the downhole filter housing, and radial holes are made on the inner surface of the cylindrical resonator body, communicating with a cavity inside the downhole filter. 3. A device for cleaning the filter element of the downhole filter according to claim 1 or 2, characterized in that the resonators are installed on parts of the housing of the downhole filter that are free of the filter element. 4. The device for cleaning the filter element of the downhole filter according to claim 3, characterized in that the downhole filter contains a nipple and a sleeve, and the resonators are made directly near them.

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