RU2556738C1 - Well strainer filtering element cleanout device - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device comprises a resonator installed inside the case of well strainer, source of pulsations. Well strainer is installed at the lower end of flow column inside the casing. Source of pulsations is installed in cavity of the well strainer and coupled to a log cable with oscillation generator, which is coupled by electrical connections through a coupling device to PC. Flushing fluid feed pipeline is connected to the flow column. Flushing fluid return pipeline is connected to a gap between the casing and the flow column, and frequency sensors and pulsation amplitude sensors are installed at the above pipeline. Resonator may be made as a cylindrical case with resonant cavity inside it; the case is concentrated inside the well strainer case. At inner surface of the resonator case there are radial openings connected to the cavity of the well strainer.

EFFECT: raised efficiency of clean-up and reduced time for repair.

4 cl, 5 dwg

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: - cleaning asphalt-resinous and paraffin-hydrated deposits (soluble), - cleaning solid mechanical deposits (sand, clay, dolomite and other insoluble impurities).

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

The known method and device for cleaning the downhole filter according to the patent of the Russian Federation for the invention No. 2332560, IPC E21B 43/00, publ. August 27, 2008

The downhole 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: the ability to clean only from tar and paraffin deposits and the need to supply electricity to a great depth.

A known method and device for cleaning a downhole filter according to the patent of the Russian Federation No. 2382178, IPC E21B 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 E21B 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.

Disadvantage: the need for periodic replacement of power elements installed inside the downhole filter due to clutter of its internal section. A device for cleaning the 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 a. St. USSR 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 the inlet fitting, and acoustic resonators made in the form of a set of parallel plates placed coaxially on the working surfaces of the reflector and pressure plate, as well as located along both sides of the filter elements with lattice discs with countersink holes.

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

Objectives of the invention: a significant improvement and acceleration of the cleaning of the downhole filter.

The solution of these problems was achieved in a device for cleaning the filter element of the well filter, containing at least one resonator mounted inside the case of the well filter and a pulsation source, in that the well filter is installed at the lower end of the tubing string inside the casing string, and the source pulsations installed in the cavity of the downhole filter and connected by a geophysical cable to the oscillation generator, which is connected by electrical connections through a device matching objects with a flushing fluid supply pipe is connected to the tubing string, a flushing fluid return pipe is connected to the gap between the siege string and the tubing string, on which pulsation frequency and amplitude sensors are mounted. 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 are made directly near them.

The invention is illustrated in FIG. 1 ... 5, where

- in FIG. 1 shows a diagram of a device

- in FIG. 2 shows a resonator circuit,

- in FIG. 3 shows the power supply circuit of the pulse generator,

- in FIG. 4 shows a well filter with a single resonator,

- in FIG. 5 shows a downhole filter with two resonators.

A device for implementing a well filter cleaning (Fig. 1 ... 5) is intended for cleaning a well filter 1 mounted on a tubing string — tubing 2 inside the 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 attached, 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. Inside the downhole filter 1, a source of pulsations 13 has been established, to which a geophysical cable 12 is connected. Inside the downhole filter 1, at least one resonator 15 is installed in the cavity 14.

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 other end of the geophysical cable 12 is connected by electrical connection 21 to an oscillation generator 27, which is connected to an object matching device 26 (USO), the input of which is connected by a communication line 21 to a computer 20. On the return line of the washing liquid 19, pulsation frequency and amplitude sensors are installed, respectively 25 and 25a. The sensors 25 and 25a communication lines 21 are connected to the input of 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. In FIG. 4 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. 4). It is preferable to install two filter elements 15 directly near the coupling 32 and the nipple 33 (Fig. 5).

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 pipe 10 to the cavity 14 of the tubing 2 pipe and then to the downhole filter 1, then through the gap 16 to the cavity 17 of the manifold 18 and then returned via the discharge pipe 19 to the tank 6.

The inclusion, frequency and amplitude of the pulsations is controlled by computer 20. Computer 20 supplies the control signal through USO 26 to the pulse generator 25 and then through the geophysical cable 12 to the pulse source 13. The pulse source 13 creates pressure pulsations in the cavity 15 and inside the well filter 1. As a result of this, the solid particles from the outer side of the downhole filter 1 are separated from the filter element 35 and fall into the gap 16 and then through the return pipe of the washing liquid 19 into the container 6.

The ripple amplitude sensors 25a measure the ripple amplitude and, when it increases, adjust the ripple frequency of the pulse source 13 to a maximum, i.e. before the onset of resonance. The frequency sensor 25 captures the 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. A device for cleaning a filter element of a well filter, comprising at least one resonator installed inside the case of the well filter and a pulsation source, characterized in that the well filter is installed on the lower end of the tubing string inside the casing, and the pulsation source is installed in cavity of the downhole filter and is connected by a geophysical cable to an oscillation generator, which is connected by electrical connections through a device for matching objects with a computer, to the pump string flushing fluid supply pipe is connected to the o-compressor pipes, a flushing fluid return pipe is connected to the gap between the siege column and the tubing string, on which pulsation frequency and amplitude sensors are installed. 2. The device for cleaning 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 the cavity inside the downhole filter. 3. A device for cleaning a downhole filter according to claim 1 or 2, characterized in that the resonators are installed on parts of the downhole filter housing that are free of the filter element. 4. The device for cleaning 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.

Images