Method of feeding reagent into well tubing

FIELD: oil and gas production.

SUBSTANCE: proposed method consists in using tubing incorporating borehole pump and packer. Note here that borehole pump is equipped with check valve. Check valve is arranged close to and above the pump on tubing outer side to allow one-way fluid flow from tubing into tube space. Said tube space is filled with process fluid with corrosion inhibitor in required concentration. Pressure in tube space is maintained not exceeding tolerable magnitude by means of electric-contact pressure gage connected to borehole pump control unit. Reagent if injected into tubing from wellhead with tube space gate valve.

EFFECT: efficient injection, safe production of oil or gas.

1 dwg


The invention relates to technology downhole cleanup of underground equipment producing wells from sediments using solvent injection and can be used in the oil and gas industry.

There is a method of delivery of solvent to the reception of the downhole pump with armored capillary hose patent RF №2260677 (publ. 20.09.2005,). The disadvantage of this technology is the inability to fill the downhole pump and lift pipes with clean solvent without dilution of the downhole fluid, while for maximum solvent effect of the solvent should be delivered to the zone sediments without dilution, i.e. in a pure form.

Known coiled tubing technology / Mini coiled tubing as it is / Sergey Cables, Nov Fidmash // Time of the coiled tubing. - 2009. No. 29. - p.28-30/based on descent in the column lift pipes long flexible tube of small diameter with a nozzle and the rinsing of the column from the sediment feed tube of a solvent. Technology is not applicable in the lift pipe with a column of rods inside the drive to the deep plunger pump.

You know the invention of the Russian Federation No. 2194152 "Well installation to control and block the flow environment" (publ. 10.12.2002, which describes a number of technologies for installation, problem solving GP the wasps downhole production. In particular, column lift pipes above the packer and downhole pump is provided with a chamber for flow of fluid from the lift pipe annulus (POS figure 9 of the patent specification). It is obvious that the operation of productive oil reservoir located below the packer, the proposed scheme (figure 9) is impossible for the following reasons:

- reservoir fluid after the pump 40 will be free to flow through the chamber 29 in the annular space;

- according to the invention, the pump 40 is not equipped with a check valve, so pumped from the wellhead to the column lift pipes technological reagent will not linger in the column, and will flow under gravity down through the pump 40 or annulus through the chamber 29.

Coming into the annulus through the chamber 29, the reservoir fluid will go in the upper layer, and in his absence - to the surface in the annular space. The latter is undesirable from an environmental point of view as aggressive components of the produced oil and water (high salinity, presence of hydrogen sulfide and solids) will lead to violation of the integrity of the casing and subsequent contamination of the upstream reservoirs freshwater complex.

The aim of the invention is the creation of such technology operation of the said downhole equipment, which will allow safe extraction of the reservoir fluid and gas and, if necessary, without tripping, to make filling the columns of the lifting pipe (tubing) reagent, in particular solvent asphalt, resin and paraffin deposits (ARPD).

The goal is the fact that in the known technical solution (patent RF №2194152), based on the application of the column lift pipes (tubing) to pump deep, packer and special cameras with valve, submersible pump supply check valve above the pump outside tubing have a check valve providing one-way passage of fluid from the tubing annulus, the very annulus fill technical coolant with corrosion inhibitor concentration, the pressure in the annular space support is not higher than the permissible values using electrocontact pressure gauge at the wellhead associated with the remote control pump deep and filling the column lift pipes reagent lead from the wellhead at an open gate valve annulus.

Main and auxiliary equipment necessary for the implementation of the invention, represented in figure 1, where 1 is a column of lift pipes (tubing), 2 - pump, 3 - check valve above the pump, 4 - valve annulus, 5-packer, 6 - annulus between the casing lift pipes and casing (operational) column wells, 7 - valve annulus, 8 - contact manometer associated with electric pump 2.

Made technical changes according to the invention can operate underground equipment in 2 modes.

1. Exploitation of the productive formation: the mouth valve annulus 7 is closed and extracted by pump 2 production rises only on the tubing 1, as the check valve 4 in the annular space is closed hydraulic - pressure in the annular space 6 is always higher than in the column lift pipes. Until the start of the downhole pump this will, in particular, to contribute to the increased density of the fluid in the annular space.

2. Delivery reagent (solvent) in the column lift pipes: the valve 7 open, into the tubing string from the mouth pumped reagent, while the check valve 3 closes the bottom of the casing, and a check valve (C) 4 opens under the action of differential pressure and forces. In the Elevator pipe pump the required volume of reagent, approximately the same amount (or slightly less due to associated petroleum gas in the lift pipe) liquid leaks out of the valve 7 to open the container. The valve 7 is closed and leave the well is at rest at time required for the reaction of the reagent with the sediments in the lift pipe.

In subsequent pump 2 is put into operation, the dissolved deposits together with the production wells are carried by the Elevator tubes on the surface of the earth.

Note the important role of the fluid in the annular space 6. The first function - inhibiting protection tubing and operational (casing) columns from corrosion processes. The second function is a reliable closing OK 4 the simplest design due to the increased density of the fluid. This is important in the days of idle wells, when through an idle pump 2, the reservoir fluid with gas will flow into the tubing string 1. Because the moment you stop the borehole hydrostatic pressure in the annular space 6 will be higher than the pressure in the column 1, the non-return valve 4 will be securely closed.

The most common form of technical fluids in the oil and gas companies is highly mineralized water with higher density (1180-1200 kg/m3containing an effective corrosion inhibitor in a dose of 30-50 g/m3. Gas production wells in column lift pipes typically has a density of not more than 1000 kg/m3so even a slight pressure drop sufficient for the efficient operation of the check valve 4 and twisting during the downtime of the well.

Contact manometer 8 is connected with the control operation of the pump 2, namely: disables the power supply to the pump when the pressure in the annular space 6 above the permissible value. This abnormal situation may occur when the pump is on and the sudden or gradual blockage of the lift pipes or onshore pipelines from wells sediments of different nature: ASPO, mechanical impurities or foreign objects.

The inventive method is implemented by the following simple actions.

1. With the remote control to stop the operation of the downhole pump 2.

2. The valve 7 is connected with a mobile tank trucks or CA-320.

3. The valve 7 open, and in the column lift pipe from the wellhead pump the required volume of reagent (solvent).

4. The valve 7 is closed and the well is left alone for the time necessary for dissolving deposits in the tubing.

5. The valve 7 reopens the add annulus additional volume of process fluid.

6. The valve 7 is closed, and pump 2 are allowed to work in normal mode.

Proposed to the examination method is particularly relevant for wells equipped with sucker rod pump (SRPS) for 2 reasons:

- the role of the non-return valve 3 perform regular valve plunger pump;

- Elevator Tr is such wells, generally covered by ASPO because of low productivity, with the consequent increase the load on the column bars.

In our opinion, the proposed solution meets the criteria for "significant difference" and "novelty", as first proposed to operate well with permanent unilateral hydrodynamic connection between the column tubing and the annular space and the annular space is reliably protect the corrosion inhibitor in the composition of the heavy technical liquids. To use already existing hydrodynamic connection (check valve 4 in figure 1) when the downloading reagent (solvent) in the Elevator pipe open end communicating vessels, i.e. the valve 7 annulus.

The goal according to the invention is performed, and the economic effect is to successfully address the delivery of the reagent in the Elevator tube. And this leads to reduction of expensive reagent. Associated, but important effect is the preservation of the casing and operational (casing) columns from corrosion processes. There are also third - scientific effect. The difference between the volumes of injected reagent and released the fluid mixed with aerated oil from the valve 7 can be estimated gas content in oil lift pipes and other issues the state is of different fluids under pressure.

The method of delivery of the reagent to the column lift tube wells, which consists in the use column lift pipes with deep pump and packer, wherein the submersible pump supply check valve above the pump at the nearest distance to it come from the external side of the Elevator pipe check valve providing one-way passage of fluid from the lift pipe in the annulus itself annulus fill technical coolant with corrosion inhibitor concentration, the pressure in the annular space support is not higher than the permissible values using electrocontact pressure gauge associated with the remote control operation of the downhole pump and the injection of the reagent to the column lift pipes are from the wellhead at an open gate valve annulus.


Same patents:

FIELD: oil and gas industry.

SUBSTANCE: according to the method of oil-gas wells killing on deep water subsea deposits by pumping of certain volume of kill composition together with sea water into the well thus providing creation of killing spout in the well with timeless pressure on formation exceeding formation pressure not less than 1.2 times, as a killing composition, preventing immediate contact of cold sea water with overheated formation fluids and productive stratum of formation, large hydrophobic disperse system is used with density exceeding density of sea water more than 5 times in the volume ensuring in bottom-hole zone of the well creation of spout of large hydrophobic disperse system with height exceeding productive stratum formation opened by perforation not less than 3 times. Mentioned disperse system is a disperse system with volume of 70%, where as disperse medium hydrocarbon liquid is used, this liquid doesn't set solid under temperatures to -10°C, its density is not less than 0.860 g/cm3; as disperse phase a mixture of hard metal balls with diameter within 1-2 mm is used, 50% of this ball mixture volume have fusion temperature well over bottom-hole temperature, and the other 50% of this ball mixture volume have fusion temperature 10°C and more below bottom-hole temperature.

EFFECT: improving reliability of oil-gas wells killing on deep water subsea deposits with excessive temperature and pressure of productive formation.

3 cl, 2 tbl

FIELD: oil and gas industry.

SUBSTANCE: typical well operating equipment can include separator for separation of water from oil, in which the produced mixture of fluid media is obtained and mixture is divided into the corresponding water and oil flows. Water flow can be pumped back to the well. For that purpose, well system for water pumping speed control back to the well can be developed. Group of inventions provides the improvement of well flow control efficiency. Essence of inventions: well equipment designed for receiving fluid medium flows through the first and the second fluid medium flow passage channels is arranged in the well. The above equipment includes flow separation control having the device connected to the first channel and the device connected to the second channel, which are interconnected. Outlet flows in the first and the second channels are controlled by means of the control.

EFFECT: increasing outlet flow in one of the first and second channels in response to increase in outlet flow in the other of the first and the second channels by means of action on one of the above devices to keep constant ratio of outlet flows in the above channels.

16 cl, 6 dwg

FIELD: oil and gas production.

SUBSTANCE: method includes gaslift well operation by adjusting the flow rate of working and produced gas. The withdrawal of produced gas is done by tubing string and additional tubing string. The flow rate of working and produced gas is adjusted by opening and closing of driven shut-off elements in accordance to the control signals. Control signals come from automatic control unit and are generated according to the results of measured values compared with set parameter values. Note that the pressure is measured in the mouth and bottom hole, at the same time the flow rate of produced gas is measured. The flow rate of working and produced gas is adjusted in such a way to provide the specified well operation mode.

EFFECT: increase of well operation efficiency, reduction of level and removal of fluid accumulated in bottom-hole zone, provision of well operation stability.

2 cl, 1 dwg

FIELD: oil and gas production.

SUBSTANCE: system for use in the hole includes the string designed for location in the hole that consists of submersible electric pump, the first part of inductive coupler and completion section. Note that completion section is located in the well zone under development and includes the second part of inductive coupler, isolating packer, detection cable and electric device electrically connected to the second part of inductive coupler. Note that detection cable goes through the packer for provision of sensors to some well zones.

EFFECT: increase of system operation efficiency and collection of measurement data referred to the well characteristics.

28 cl, 7 dwg

FIELD: oil and gas industry.

SUBSTANCE: well of hydrocarbon raw material deposit, either gas one or gas-condensate one, includes production string with tubing string with underground operating equipment. Operating equipment includes at least a cutout valve with remote control, which is provided with an actuator, and well head with wellhead equipment. Wellhead equipment comprises casing head, tubing head on which there mounted is X-tree in the form of a fir tree, which includes shutoff members - master and side gate valves with actuators, as well as throttle valve adjacent to the latter, which controls the well flow rate and is provided with an actuator, and monitoring and control members - fuse insert and gas line pressure monitoring valve. Well is connected to control station by means of shutoff members, throttle valve and cutout valve. Control station is made in the form of a cabinet and includes pump accumulator plant and at least one control unit per well.

EFFECT: improving reliability and accident-free operation of gas well and simplifying the control of processes.

12 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: opening and closing of shutoff-control valves of well cluster is performed by independent supply of working medium to actuators of shutoff-control valves and underground cutout valves in the specified sequence, as well as valves controlling the flow rate of each well. Method is implemented by means of control station mounted in the cabinet and including instrumentation and control, as well as hydraulic system. Hydraulic system includes pneumatic hydraulic pressure accumulators combined with working medium tank, pumps, pressure controls and multiplying gears, and has the possibility of controlling actuators of shutoff-control valves with time delay and in certain sequence. At that, in addition, control lines of loop and flare gate valves are mounted in cabinet of the station, which are installed on pipelines in close proximity to control cabinet, for example on one common frame.

EFFECT: invention simplifies mineral deposit production control process, as well as allows reducing the area occupied with process equipment.

21 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: single wells or wells forming clusters are drilled; production wells are equipped with wellhead equipment with X-tree including at least one side gate valve and one master gate valve, as well as underground cutout valve and throttle valve and monitoring and control members, which are installed on the loop, for example, fuse strip and gas line pressure monitoring valve. Operation of the well is performed at simultaneous control of production processes of hydrocarbons by means of the station. Control processes involve opening and closing of shutoff-control valves of well cluster by independent supply of working medium to actuators of shutoff-control valves, as well as flare and loop gate valves, which are arranged on pipelines in close proximity to control cabinet, for example on one common frame with control cabinet. Opening of shutoff-control valves of each well is performed in the following way: underground cutout valve, master gate valve, loop gate valve, side gate valve; closing is performed in the reverse order.

EFFECT: improving operating reliability of shutoff-control valves.

3 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: well cluster includes at least two wells. Each well includes underground operating equipment containing cutout valve and wellhead equipment having casing head, tubing head on which there mounted is X-tree including shutoff members - master and side gate valves. Well cluster is connected to control station of actuators of shutoff members, which is made in the form of a cabinet. Control station includes power lines of function control of shutoff members' actuators. In addition, control lines of loop and flare gate valves are mounted in the cabinet. Loop and flare gate valves are installed on pipelines in close proximity to control cabinet, for example on one common frame.

EFFECT: reducing the surface area occupied with the equipment and increasing cluster operating safety.

12 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: control method of X-tree consists in opening/closing of shutoff-control valves by supplying the working medium to mechanisms of actuators of underground cutout valve, side and master gate valves by means of control station. Control station includes pneumatic hydraulic system connected through monitoring sensors of station operation parameters to control unit of the station. As control unit there used is software-and-hardware system with local control panel containing a display with sensor control to enter commands in on-line mode and local keyboard.

EFFECT: improved operating reliability of the control station and simpler design of the latter.

18 cl, 3 dwg

FIELD: process engineering.

SUBSTANCE: invention relates to operation of oil production wells. Differential filter comprises swelling polymer applied on matrix particles to swell after contact with water to decrease filter permeability. Polymer is selected from polyacrylic acid or polymethacrylic acid, polymaleic anhydride, acrylamide polymer, polyamide, polyester, latex, and polyvinyl alcohol. Method of adjusting water ingress into well comprises incorporating claimed differential filter into wall bottom for operation therein. Note here that differential filter permeability decreases after contact with water.

EFFECT: controlled water ingress.

18 cl, 2 dwg, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: method of reactant impulse treatment of bottom-hole formation zone includes replacement of killing liquid in casing string with active liquid reactant medium upon simultaneous repressive-impulse action, when active liquid reactant medium reaches roof of productive formation it is pumped into bottom-hole formation zone under repressive-impulse action, then there is repeated implosion action with formed passive medium being removed from bottom-hole formation zone, the passive medium contains products of destruction of asphalt-resin wax deposits and of other colmataging formations, till pumped volume of active liquid reactant medium is removed, then bottom-hole formation zone is treated through annular space under repressive-depressive impulse action of killing liquid with addition of water-repellent SAS, active liquid reactant medium is used as a solvent with addition up to 5 wt % SAS, the pumping is performed under nanowave repressive-impulse action with alternating depressive impulses. Plant for reactant-impulse treatment of bottom-hole formation zone, containing casing string, installed in succession swabing device, packer, impulse depressive generator which radial channels are at the same level with lower perforation holes of well perforation interval, the generator is installed on day surface with possibility of connection to both casing string and annular space, impulse wave depressor with discharge chamber provided with free hydraulic output to reservoir, is provided with pressure multiplier with impulse nanogenerator installed before impulse depressive generator.

EFFECT: recovery and increase of efficiency and initial permeability of well bottom-hole formation zone.

2 cl, 1 ex, 1 dwg

FIELD: oil and gas industry.

SUBSTANCE: invention pertains to method for removing deposits from pipelines and can be used in oil and gas industry for cleaning oil-gathering pipelines from deposits with the help of solvents. Method consists in filling the pipeline with solvent, holding the time for deposits dissolving and start of pipeline operation. The finish of oil-gathering pipeline with deposits filling with solvent is defined by regular samples from sampling device at the end of the pipeline. The time necessary for deposits dissolving is divided by intervals and in each time interval the solvent is returned from pipeline into initial reservoir due to elastic energy of liquid-gas mixture in pipeline for evaluation of residual dissolving capacity of the solvent, and then it is again pumped into the pipeline. If necessary, the operation of productive wells connected to the oil-gathering pipeline after processed area is used for solvent reverse movement into the initial reservoir.

EFFECT: increase of chemical agents application efficiency and extension of oil-gathering pipelines service life.

2 cl, 2 dwg

FIELD: oil and gas industry.

SUBSTANCE: unit contains a housing with opening cover. Inside the housing there are arranged control unit with electrical equipment, hanged tank for chemical agent provided with agent availability control system and dosing pump. The reservoir is provided with filling hole for chemical agent. In control unit there are dosing pump control circuits located. The reservoir is installed by means of assembly functioning both as fastener and as weight measuring system. On the upper part of the reservoir the assembly contains two distant from each other metallic slats rigidly fixed with the housing. Assembly is provided with two U-shaped levers consisting of beam and branches. Levers are installed under mentioned slats in inversed manner with beams towards each other. Each lever is connected by branches body to the first and the second slats by means of hinged joint. End parts of branches of U-shaped levers, closer to end ones, are connected to the reservoir by means of hinged joint. Levers beams are connected to each other by means of hinged joint of each beam with strain-measuring sensor which outlet is connected to control unit.

EFFECT: simplifying the design, improving operating reliability, reducing material costs.

8 cl, 5 dwg

FIELD: oil and gas industry.

SUBSTANCE: device is made in the form of box body installed on carriage frame of transport vehicle and divided into instrument compartment and process compartment by means of blind sealed partition. Control cabinet, flushing water tank, water supply station, direct-flow water heater, earthing cable and powder fire-fighting module is installed in instrument compartment. Tanks for various types of chemicals with a dosing pump for each of them, drain tank, self-priming pump, powder fire-fighting module, video camera, electric contact pressure gauges, safety valves, non-return valves, flow metres, suction lines, delivery lines and explosion-proof control stations are installed in process compartment. Each tank is provided with possibility of being changed over to dosing pump of any other of the above tanks. Plant is equipped with connection assembly to the treated well, which allows disconnecting the delivery line from treated well and in case it is impossible to close the pipe gate valve, or with pipe gate valve passes, as well as with power supply in the form of synchronous generator located in the front or rear part of carriage frame cardan drive from power take-off device of transport vehicle.

EFFECT: increasing the number of treated wells during a working shift.

3 cl, 1 dwg

FIELD: oil and gas production.

SUBSTANCE: method consists in circulation of washing compound in the well for 3-6 hours at flow rate 5-10 l/s, washing out the reaction products from the well by water in well volume, bottom flushing by water in volume not less than 1.5 of well volume. Washing compound represents a mixture that contains, parts by volume: solvent of asphaltic-resinous-paraffin deposits "INTAT-4" - 100-360, chemical reagent ITPS-04-A - 45-60, service water with density from 1.0 to 1.18 g/cm3 - 1000.

EFFECT: in case of flexible tubes they are reciprocated in the course of circulation from the bottom to the top of productive stratum.

2 cl

FIELD: oil-and-gas production.

SUBSTANCE: proposed device comprises tubular container located under downhole pump and tube to feed solvent from surface into container. The latter has open bottom and comprises heater with output varying over its length. Container inner surface is coated by heat-insulation composition. Degree of solvent heating in container and its displacement is estimated by means of temperature transducers arranged regularly over container length.

EFFECT: higher efficiency of cleaning.

1 dwg

FIELD: oil and gas industry.

SUBSTANCE: method includes stages at which cloudy treating fluid with primary microbial population is provided. The fluid is placed in self-contained road mobile manifold of treatment by ultra-violet, which contains source of ultra-violet. Cloudy treating fluid is treated using source of ultra-violet in the presence of weakening reagent to form irradiated treating fluid. Then irradiated treating fluid is supplied to mixing system. Mobile system of treating fluid treatment by ultra-violet contains inlet device, source of treating ultra-violet, chamber for treatment by ultra-violet, weakening reagent, outlet device. At that system of treating fluid treatment by ultra-violet is transported using self-contained road mobile platform.

EFFECT: increasing efficiency of treating fluids disinfection.

12 cl, 2 tbl, 8 dwg

FIELD: oil and gas industry.

SUBSTANCE: equipment complex for production of high-viscosity oil comprises a lifting pipe with an oil pump drive installed inside and a mounted assembly from an oil pump, a perforated section of a pipe with a pump anchor and a well device. The well device is made in the form of a cylindrical vessel, in which there is a tight cavity and a circular chamber serially arranged with radial channels in its vessel. Besides, in the tight cavity there is a source of elastic oscillations of high frequency made as an ultrasonic converter of circular shape. The tight cavity along the assembly axis is equipped with a brace having an inner through channel leading to a circular chamber. The well device is connected with an electric cable to a ground power supply source. At the same time the complex is complemented with a ground pump, a line of liquid chemical reagent supply via an inner channel of the tight cavity brace into the circular chamber. The perforated channel of the pipe between the oil pump and the pump anchor is equipped with a hole for supply of a power supply cable and a chemical reagent supply line.

EFFECT: higher efficiency of ultrasonic treatment due to intensified additional chemical impact at oil into a casing pipe.

4 cl, 2 dwg, 3 tbl, 1 ex

FIELD: oil and gas industry.

SUBSTANCE: device includes a reagent tank and dosing pump interconnected with it and having its own drive and control system. Device is placed inside the well below oil-extracting equipment. Power is supplied to dosing pump drive from battery of electrolytic cells located in air-tight cavity of the device.

EFFECT: effective reagent supply; higher protection reliability of the whole submersible unit.

6 cl, 4 dwg

FIELD: oil and gas industry.

SUBSTANCE: method involves supply of solvent to bore-hole pump inlet by means of flexible wear-resistant small-diameter tube through annular space. The required amount of solvent is supplied under packer through its transient channel with non-return valve at the stopped bore-hole pump and closed damper at the outlet of flow column on the well head. After that, such solvent volume V1 is supplied by means of bore-hole pump from the available solvent volume under the packer to flow column, which will fill in the flow column space free from deposits. Well is stopped for the period of time required for dilution of maximum possible part of deposits with volume V1deposit; after that, during the second cycle the solvent with volume V2 = V1 + V1deposit is pumped with bore-hole pump to flow column with further dilution of deposits at the stopped well. Such cyclic filling of flow column with the solvent is continued until the solvent coming out of flow column onto the well head contains inconsiderable content of deposit elements.

EFFECT: improving the cleaning quality.

2 cl, 1 dwg

Check valve // 2455546

FIELD: oil and gas industry.

SUBSTANCE: check valve has housing 1 with installed on it shutoff member in the shape of a ball 8. Ball 8 is installed in stepped shell 7 with axial through channel. Shell 7 is provided with upper trap of ball 9 and seat 10. Seat 10 is located in site of coupling of axial channel parts with cross-sections different from each other. Shell has radial through holes 11 in upper part of side wall. Spring 3 is installed inside valve. Spring 3 is located on lower limit stop 2 installed in housing 1 with possibility of axial movement. Valve has additional shutoff member in the form of the second ball 13. Ball 13 is installed in sleeve 12 with axial channel of variable cross-section and seat 14. Seat 14 is located in upper part of sleeve 12 in site of coupling of axial channel parts with cross-sections different from each other. In side walls of sleeve there are through holes 15 made. Stock 16 is installed in axial channel of sleeve 12. Stock 16 interacts with ball 13 and is sprung by spring 3. Flow splitter in the form of bushing 4 is installed in housing 1. Shell 7 is fixed on upper end of bushing 4, sleeve 12 is fixed on lower end of bushing 4. There are at least two channels 5 of forward flow and at least two channels 6 of backward flow inside bushing 4.

EFFECT: increasing reliability of valve operation due to improving of its tightness.

2 cl, 4 dwg