RU2267608C2 - Hydroimpulsive well bottom zone treatment device - Google Patents

Abstract

FIELD: oil production, particularly equipment for well bottom zone cleaning by exerting hydropulsive action on well bottom zone.

SUBSTANCE: device comprises flow distribution with chemical reagent injection channel, nozzle, mixing chamber and pressure accumulator. The pressure accumulator comprises elastic ball and body with contraction tube and diffuser. The second channel with check valve is formed in distributor body. Shutoff valve with differential piston is installed in the first channel. The greater piston diameter faces bottomhole formation zone. Pressure accumulator with elastic ball arranged in lower part thereof is provided with movable seat and return spring resting upon protective grid.

EFFECT: increased oil output from well due to improved collecting properties, possibility of well bottom treatment only through tubing string.

1 dwg

Description

The invention relates to the oil industry, in particular to equipment for cleaning the bottom-hole zone of a well by hydro-pulse treatment.

A device is known for influencing the bottom-hole zone of a well (RU No. 2151283 C1, 06/20/2000), which includes an injection and discharge chamber with openings for fluid flow, separated from each other by a locking element in the form of a ball located in a conical saddle. The ball is made of an elastic material that changes shape under the influence of pressure, and when punching through the chamber, a series of hydraulic shocks occurs.

The disadvantage of this device is a slight increase in the productivity of the well after exposure in case of destruction of the adsorption layer and the creation of mud products and, as a result, the short-term effect observed.

The closest in technical essence to the present invention is a device for hydrodynamic impact on the bottomhole zone of the well, comprising a housing, injection and discharge chambers, separated from each other by a locking element in the form of a ball made of elastic material, a jet pump is installed in the upper part of the device, hydraulically connected with the discharge chamber of the hydrodynamic device by an eccentric channel, with a saddle in the upper part of the channel, locked by a ball valve, reset from the wellhead (RU No. 29333 U1.10.05.2003).

The disadvantage of this device is the inability to repeatedly change the processing modes of the bottomhole zone of the well without lifting the tubing string.

The objective of the invention is to develop a device for hydro-pulse treatment of wells, allowing repeatedly to produce cycles of treatment of the bottom-hole formation zone with different chemicals and for a long period of time to increase the productivity of wells.

The problem is solved in that the device for hydro-pulse treatment of the bottom-hole zone of the wells contains a flow distributor with a channel for injecting a chemical reagent, a nozzle, a mixing chamber and a pressure accumulator, including a housing with a confuser and a diffuser and an elastic ball, and the second channel with a check valve, and in the first channel there is a shut-off valve with a differential piston, the larger diameter of which is facing the bottom-hole zone of the formation, while the pressure accumulator with electric The ball at the bottom is equipped with a movable seat and a return spring resting on a protective grill.

The drawing shows a structural diagram of a device for hydro-pulse treatment of the bottom-hole zone of wells.

The device consists of a pressure accumulator 1, including a housing 2 with a confuser 3 and a diffuser 4, an elastic ball 5, protective grilles 7 and 8, a movable seat 9 and a return spring 10. The diffuser 4 and the confuser 3 are hydraulically connected through a critical channel 6.

The upper threaded part of the pressure accumulator 1 is screwed through a threaded sleeve 11 with a flow distributor 12, including a housing 13 with channels 14 and 15, a nozzle 16, a mixing chamber 17, a diffuser 18, a shut-off valve 19 with a differential piston 20 mounted on the channel for chemical reagents injection 15, and a check valve 21 mounted on the channel 14.

The device operates as follows: with a closed annular valve at the wellhead using the hydraulic lock principle to prevent chemical reagents from entering the annulus through the nozzle 16, the mixing chamber 17 and the outlet diffuser 18 chemical reagent (clay acid) from the pump unit through the tubing string 22 through channel 15 enters the shut-off valve 19, with increasing pressure, the differential piston 20 of the shut-off valve 19 moves down and through the openings 23 the working solution enters the upper chamber 24 of the battery and pressure 1 and fluid pressure presses the elastic ball 5 to the confuser 3, while blocking the critical channel 6. When the calculated pressure is reached, the elastic ball 5 begins to deform and push into the critical channel 6 and then into the diffuser 4. Continuing to move, the elastic ball 5 pushes the movable the seat 9, compressing the spring 10. At this time, in the space under the packer 27 there is a sharp jump in pressure (water hammer) and the working fluid through the perforation holes 25 enters the bottomhole formation zone 26.

After stopping the flow of the working solution, the spring 10 pushes the movable seat 9 and presses the elastic ball 5 against the diffuser 4, blocking the critical channel 6. By opening the pipe valve at the wellhead, the pressure in the tubing string 22 decreases to hydrostatic, while the differential piston 20 of the shut-off valve 19 returns to its original position, while blocking the hydraulic connection through the channel 15 between the tubing string 22 and the upper chamber 24 of the pressure accumulator 1. At the same time, the check valve 21 opens between the column H T 22 and the upper chamber 24 there is a hydraulic pressure accumulator 1 through the communication channel 14 and the nozzle 16. The pressure in upper chamber 24 and the pressure accumulator is reduced to hydrostatic. The excess pressure generated in the under-packer space 28 due to the injection of the working solution into the perforation zone, the elastic ball 5 is forced through the critical channel 6 into the upper chamber 24 of the pressure accumulator 1, while the pressure in the under-packer chamber decreases sharply to hydrostatic, which helps to separate the colmatant and reaction products .

Subsequent cycles of shock-chemical exposure are repeated in the same sequence.

Removal of colmatant and reaction products from the bottomhole formation zone is as follows.

Having opened the annular valve at the wellhead, the pumping unit pumps the flushing fluid (water) into the tubing string 22. From the tubing string 22, water is supplied to the nozzle 16, mixing chamber 17, the outlet diffuser 18, and then through the annular space to the wellhead. In this case, an ejection effect occurs and a pressure drop occurs in the channel 14, as a result of which the check valve 21 opens and a hydraulic connection appears between the under-packer space 28 and the mixing chamber 17. There is a pressure drop in the under-packer space, which is hydraulically connected through the openings 25 to the bottomhole formation zone 26, formation fluid from the bottom-hole zone of the formation 26 through the holes 25 enters the under-packer space 28 and then through the pressure accumulator 1, the channel 14 of the flow distributor 12 enters the mixing chamber 17 , where, mixing with the flushing fluid, through the outlet diffuser 18 through the annular space it is fed to the wellhead, taking with it the mud and reaction products formed as a result of the reaction of the chemical reagent solution (clay acid) and hydraulic impulses.

If necessary, several cycles of injection of various chemical reagents into the bottom-hole zone of the formation and the selection of reaction products and colmatant at the wellhead without additional tripping and changing equipment are performed.

EFFECT: invention enables effective transfer of formation fluid from stagnant zones and channels to zones of active drainage with the possibility of removal of colmatization material and reaction products immediately after treatment in a different sequence, allowing to increase well production by improving reservoir properties of the formation, and the entire processing cycle is carried out only along the tubing string .

Claims (1)

A device for hydro-pulse treatment of the bottom-hole zone of wells, containing a flow distributor with a channel for injecting a chemical reagent, a nozzle, a mixing chamber and a pressure accumulator including a housing with a confuser and a diffuser and an elastic ball, characterized in that the second channel with a check valve is made in the flow distributor housing and in the first channel there is a shut-off valve with a differential piston, the larger diameter of which is facing the bottom-hole zone of the formation, while the pressure accumulator with an elastic ball in the bottom it is equipped with a movable portion of the seat and a return spring resting on the safety guard.