RU2295630C2 - Device for cleaning mudded surfaces of filters and well walls - Google Patents

Abstract

FIELD: mining industry, in particular, operation of oil and water-intake wells, possible use for cleaning filters from mudding precipitations, preventing influx of useful product into well.

SUBSTANCE: device includes casing column with filter, operation column and immersed pump. In accordance to invention, operation column is composed of water-lifting pipe, branch pipe and body rigidly connected to it. Water-lifting pipe is engaged with branch pipe by means of a barrel. Positioned in the barrel is rotation unit with thrust bearing to provide for possible rotation of branch pipe with the body relatively to water-lifting pipe. Mounted on the body at various levels are cavitation devices, positioned at angles of 18-22° relatively to generatrix of body and at angles of 45-50° relatively to horizontal plane. Immersed pump is located on the tail of operation column.

EFFECT: increased productiveness of device, expanded functional capabilities, increased degree of cavitation and hydrodynamic effect on mudded surface of filter.

2 cl, 1 dwg

Description

The invention relates to the mining industry, in particular to the operation of oil and water wells, and is intended for cleaning filters from clogging deposits that impede the flow of a useful product into the well.

It is well known that during the operation of oil and water wells there is a gradual migration of the finely dispersed rock fraction (colmatant) of the productive horizon from the depth of the formation to the prefilter zone of the well.

This process is characterized by a change in the filtration characteristics of the bottomhole formation zone and directly downhole filters, namely, a drop in the dynamic level and flow rate of the pumped liquid. There are many ways to artificially reduce the hydraulic resistance of a formation and filter surface.

A known method of washing the filter and the filter zone of the well, including installing equipment in the filter and working parts of the well, supplying an aggressive flushing medium, followed by pumping it out of the well (1).

The disadvantage of the described method is the high cost of its implementation, the fragility of the equipment used due to the use of filter media that are aggressive to the material, and environmental degradation.

There is also known a device for pumping liquids with mechanical impurities from a well, including a pump unit containing a submersible pump, discharge and suction pipelines, an ejector and a strainer - prototype (2).

The disadvantage of the described technical solution is the lack of cleaning efficiency of the filter due to the low degree of cavitation of technical means and insufficient productivity of the device.

The technical result expected from the use of the invention is to increase the productivity of the device, expand the functionality, increase the degree of cavitation and hydrodynamic effects on the sealed surface of the filter.

The specified technical result is achieved by the fact that in the device for cleaning the stained surface of the filter and the walls of the wells, including a casing with a filter, a production string and a submersible pump, the production string is made up of a water pipe, a pipe and a housing rigidly connected to it, and the water pipe is connected with a nozzle by means of a cup in which a rotation unit with a thrust bearing is placed to allow rotation of the nozzle with the housing relative to the water Removable tube, wherein the housing at different levels are mounted cavitators angled 18-22 ° with respect to the housing and forming an angle of 45-50 ° relative to the horizontal plane, and a submersible pump disposed on the tail of the production string. The specified technical result is also achieved by the fact that the cavitators are equipped with electrovalves operating sequentially in automatic mode according to the scheme from top to bottom.

The invention is illustrated in the drawing, which schematically shows a device for cleaning stained surfaces of a filter in a flooded state, and the walls of the wells.

The device consists of a casing 1 with a filter 2, production casing, which consists of a riser 3, a pipe 4 and a housing 5 located inside the filter cavity. The water-lifting pipe 3 is connected to the pipe 4 by means of a cup 6 with a cover 7 and a fastening unit consisting of a nut 8 with a lock nut 9, sealing cuffs 10 between which a thrust bearing 11 is placed, and a supporting washer 12. On the outer surface of the housing 5 at various levels are mounted cavitators 13 with electrovalves. Cavitators are located at an angle of 18-22 ° relative to the generatrix of the body and at an angle of 45-50 ° relative to the horizontal plane. On the tail of the production casing there is a submersible pump 14, which serves to pump out water during the operation of the well and create the necessary hydraulic pressure for the effective operation of cavitators.

The device operates as follows: when the water level in the casing string 1 drops, i.e. when the intensity of water inflow through the filter 2 decreases due to its clogging by rock particles of the prefilter zone, a signal comes from the control unit located on the surface (not shown in the drawing) and the water pipe 3 automatically shuts off. At the same time, the first solenoid valve automatically opens counting from the wellhead, from the cavitators 13. Having closed the water-lifting pipe 3, the water flow is directed to the first cavitator 13, and the hydraulic pressure of the liquid developed by the submersible pump 14 creates the conditions for Hydrodynamic cavitation and impact on zakolmatirovannuyu filter surface adjacent to the zone 13 cavitator.

After a certain period of time, which is determined experimentally for the specific conditions of each aquifer, the valve of the first cavitator 13 closes with the simultaneous opening of the valve of the second cavitator and so on, until all cavitators located in the prefilter zone work out. Under the influence of the reactive force of the water flowing from the diffuser of the cavitator 13, the pipe 4 and the housing 5 with cavitators placed on it begin to rotate. As a result of rotation of the housing around its axis, the cavitational and hydrodynamic effects of the cavitators 13 are performed not on the limited sector area of the filter, but on its entire cylindrical surface, i.e. the area of effective operation of the cavitators 13 is increased several times, reducing the filter cleaning time.

As soon as the water level in the casing is restored to its original value, which indicates the cleaning of the filter surface, the signal from the level gauge (not shown in the drawing) will be sent to the control unit, which will command the actuating relay to open the electro-hydraulic valve on the riser and close the valve of the last cavitator 13. The flow rate of the well is restored, and it continues to work in normal mode.

The sequential inclusion of the cavitators 13 is necessary in order to ensure the operation of each of them in the optimal mode, because the power of submersible pumps 14 in small diameter wells cannot provide the necessary hydraulic pressure for the simultaneous operation of all cavitators 13.

The location of the submersible pump 14 below the installation level of the cavitators 13 is necessary to ensure an ejection effect in the area of operation of the cavitators, which significantly increases the efficiency and the area of influence on the sealed filter surface.

Thus, the proposed technical solution of the device has the following advantages over the known:

1. Eliminates the need to use aggressive liquids to clean the sealed filter surfaces, thereby significantly extending the validity of the latter while reducing cost costs.

2. It is possible to restore the flow rate of a well without removing a water-lifting column to the surface, which requires the installation of special equipment at the wellhead.

3. Significantly increases the effective zone of the hydroacoustic and hydrodynamic effect of the fluid flowing from the diffuser of the cavitators, significantly reducing the operating time of the cavitators required to clean the colded filter surface.

Information sources

1. Copyright certificate No. 1068616, cl. F 04 D 13/10.

2. Copyright certificate No. 912858, cl. E 03 B 3/18.

Claims (2)

1. A device for cleaning the stained surface of filters and well walls, including a casing with a filter, a production casing and a submersible pump, characterized in that the production casing is made up of a water pipe, a pipe and a housing rigidly connected to it, and the water pipe is connected to the pipe by means of a glass, in which a rotation unit with a thrust bearing is placed to enable rotation of the nozzle with the housing relative to the water-lifting pipe, while on the body all at different levels mounted cavitators located at an angle of 18-22 ° relative to the generatrix of the housing and at an angle of 45-50 ° relative to the horizontal plane, and a submersible pump is located on the tail of the production casing. 2. The device according to claim 1, characterized in that the cavitators are equipped with electrovalves that are able to work sequentially in automatic mode according to the scheme from top to bottom.