SU1696676A1 - Device for gas lift oil production - Google Patents

Abstract

The invention relates to the oil and gas industry and is intended for the exploitation of oil wells by a gaslift method. The purpose of the invention is to increase the efficiency of the device by eliminating the influence of the pressure of the injected gas on the opening-closing valves and reducing the overall stiffness of the two bellows (C). Controllable gas lift valves are installed in the well. In the hollow body (PC) 3 of each valve there are circumferentially radial holes 4 and a saddle 5 with a passage 6. At the top of the PC 3, the main C 8 is installed, it forms with the PC 3 a chamber 9 for compressed gas . Concentric in PC 3 there is a rod 10 with a bolt 11. The upper end of the rod 10 is rigidly connected with C 8. Under C 8 between rod 10 and PC 3 an additional C 12 is installed. The effective area C 12 is equal to the area of the passage channel 6 of the saddle 5. On the outer surface PC 3 are annular sealing elements 13. Above the holes 4 are made a series of additional radial channels 14. The upper end C 12 is rigidly connected with the stem 10, and the lower end is connected with the SCR. The internal cavity 15 C 12 communicates with the space behind the PCD through holes 4, and the external cavity 1 b through channels 14. Due to the equality of the effective area C 12 and the cross section of the channel 6 seat 5, the pressure of the injected gas does not change the state of the gas-lift valve, The effect of the injected gas on the valve opening and closing is appreciated. When the stock 10 moves upwards, the C 8 is compressed, and the C 12 is stretched and the rigidity of the C 8 is compensated by the elastic forces of the C 12 2 or U C S o v o VI Os

Description

The invention relates to the oil and gas industry and can be used in the operation of oil wells by gas lift method.

The aim of the invention is to increase the efficiency of the device by eliminating the influence of the pressure of the injected gas on the opening-closing valves and reducing the overall rigidity of the system of two bellows.

FIG. 1 shows the overall layout of the device in the well; in fig. 2 shows a gas lift valve installed in the side pocket of the borehole chamber.

The device includes gas-lift valves 2 installed from the well 1, pressure-controlled gas-liquid mixture, each of which contains a hollow body 3 with radial holes 4 formed around it, a saddle 5 with a passage 6, a check valve 7 located under the saddle 5, the main sylph 8, mounted in the upper part of the cus-pus 3 and forming with it a chamber 9 for compressed gas, concentrically located in the housing 3 a rod 10 with a bolt 11, the upper end rigidly connected with the main bellows 8, an additional bellows 12c eff a wide area equal to the transverse area of the bore 6 of the saddle 5, mounted under the main bellows 8 between the rod 10 and the housing 3, and the annular sealing elements 13 located on the outer surface of the housing 3. In the housings 3 valves 2 above the radial holes 4 are made a number of additional radial channels 14, the upper end of the additional bellows 12 is rigidly connected with the rod 10, and the lower end with the housing 3, and the internal cavity 15 of the additional bellows 12 is connected to the space behind the housing through radial holes 4 the housing 3, and the external cavity 16 by means of additional radial channels 14. The figures also show the packer 17, the borehole chamber 18 and the charging unit 19.

The device works as follows.

Before running into the well, the valves 2 are charged with compressed nitrogen through the charging unit 19 to a predetermined pressure value determined by the ratio

Rgzh Rzar Rzh, (1)

where Rzar is the charging pressure of the bellows 8;

Pf is the pressure of the hydrostatic liquid column in the tubing at the depth of the valve;

Pr l - the pressure of the gas-liquid mixture in the tubing at the depth of the valve after the development of the well.

The lower (working) gas lift valve is charged with compressed nitrogen according to the condition

Rszr - Rgzh (2)

After lowering and installing the gas-lift valves 2 into the well chambers 18 by injecting gas into the annulus, the well development process begins, and under the action of the hydrostatic liquid column all the valves 2 are open and the fluid flows into the tube space before the upper valve is exposed. The pressure of the fluid in the pipes through the channels 14 affects the effective area of the bellows 8. After exposing the upper valve, the gas coming from the annulus varies the liquid column located in the pipes above the valve, resulting in a gas-liquid mixture and the pressure in the pipes at the depth of the valve drops. . The bellows 8 under the action of the charge pressure Rzar, which is greater than the pressure Pg.G., acting on the bellows 8 through the channels 14, closes the gas-lift valve. Moreover, since the effective area of the bellows 12 and the cross-sectional area of the passage channel 6 of the seat 5 are equal, the pressure of the injected gas does not change the state of the gas-lift valve.

As a result of further gas injection into the annulus, the liquid flows through the below located gas lift valves 2. After the next valve is exposed, the process repeats. When the gas reaches the depth of installation of the lower (working) valve, the gas supply to the tube space adjusts with the valve itself by fulfilling the condition (2). At the same time, the valve maintains the calculated optimal operation mode of the well.

It should also be noted that when the stem 10 comes up, the main bellows 8 is compressed, and an additional 12 is stretched. The stiffness of one bellows is thus compensated by the elastic forces of the other. This installation of the main and additional bellows reduces the overall rigidity of the system, which allows for more precise control of the valve in bench conditions and increases its sensitivity to pressure changes in the tube space,

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Claims (1)

Claims of the Invention A device for producing oil by a gas-lift method, including gas injection valves installed in a well, controlled by a pressure of a gas-liquid mixture, each of which contains a hollow body with radial openings formed around it, a saddle with a flow channel, a check valve located 5 under the saddle, the main bellows, mounted in the upper part of the body and forming with it a chamber for compressed gas, concentrically located in the body a rod with a bolt, the upper end rigidly connected with 0 main bellows, an additional bellows with an effective area equal to the transverse area of the seat bore, installed under the main bellows between the rod and the housing, and the ring 5 sealing elements located on the outer surface of the housing, characterized in that. to increase the efficiency of the device by eliminating the influence of the pressure of the injected gas on the opening-closing valves and lower overall stiffness of the two bellows systems; in valve bodies above the radial holes, an additional row of radial channels is made, the upper end of the additional bellows is rigidly connected to the stem, and the lower end is connected to the body, and the internal cavity of the additional bellows is connected to the space behind the body radial holes of the housing, and the external cavity - through additional radial channels. FIG. 2  - yy aza