RU2303124C1 - Device for gas bypassing from annular space into tubing string - Google Patents

Abstract

FIELD: downhole equipment, particularly to operate, complete, kill and flush vertical, inclined and horizontal oil producing wells during gas bypassing from annular space into tubing string.

SUBSTANCE: device comprises clutch with side orifice connected to flow string from both ends thereof. Side surface of the clutch is connected to side body surface and conforms thereof over maximal possible area to increase heat transmission from the clutch to the body. The body also has longitudinal channel and side orifice connected with each other. The side orifice is in register with side clutch orifice. Jet and check valve with filter are installed in longitudinal channel of the body. Check valve provides gas bleeding as pressure in annular space exceeds that in flow string by 0.1-0.2 MPa. Device provides circulation liquid flow rate reduction by not more than 10%.

EFFECT: increased working ability in winter period at negative environment temperatures.

2 dwg

Description

The invention relates to underground downhole equipment and can be used in the operation, development, killing and flushing of vertical, deviated and horizontal oil wells during operations involving gas bypass from the annular space of the well into the tubing string.

A device for discharging oil gas from an annulus containing a tubing string, an electric centrifugal pump unit, wellhead shutoff valves, an ejector device and a check valve is known. The ejector device is located at the wellhead using a quick-detachable connection with the possibility of creating a region of reduced pressure in the receiving chamber compared to the pressure in the annulus of the well, and the check valve contains a locking pin that prevents clogging of the outlet of the check valve at high flow rates - supply of oil gas. The non-return valve seat is made removable for inspection during repairs (RF patent No. 2256779, class E21B 43/00, published. 07.20.2005).

The known device is located on the day surface at the wellhead and is subject to the influence of freezing temperatures. Negative winter temperature in combination with cooling in the ejector device leads to freezing of the liquid in the winter and loss of the device’s performance.

A device for discharging gas from the annulus, consisting of a submersible engine, hydraulic protection, a centrifugal pump and an ejector device, including a nozzle, a mixing chamber and a diffuser. At the level of the mixing chamber, a channel for bypassing gas from the annulus, equipped with a check valve, is made. When the pump is operating, the produced fluid is directed through the nozzle, creating a vacuum in the region of the mixing chamber, causing the valve to open and bypass gas from the annulus to the region of the mixing chamber. The gas, mixed with the produced fluid, enters the diffuser and then at the wellhead (RF patent No. 2079636, class E21B 43/00, published May 20, 1997).

The known device is applicable only in conjunction with a centrifugal pump and is operable only when the centrifugal pump. When the device is located near the wellhead in winter time, the device may freeze and lose working capacity.

Closest to the invention in technical essence is a device for transferring gas from the annulus of the well into the tubing string, including a housing connected at both ends with tubing with radial openings that are covered by a sleeve mounted on a threaded leaky connection outside the housing (RF patent No. 2074954, CL ЕВВ 43/00, ЕВВ 43/12, publ. 03/10/1997 - prototype).

The known device provides the passage of gas and liquid in the forward and reverse directions without the possibility of stopping the passage and adjusting the flow of gas and liquid through the device. When the device is located in close proximity to the wellhead in winter time, the device may freeze and lose its working capacity.

In the proposed invention solves the problem of improving the health of the device in winter under conditions of exposure to negative temperatures.

The problem is solved in that in the device for transferring gas from the annulus to the tubing string, including a coupling connected at both ends to the tubing with a side opening, according to the invention, the coupling is connected by the side surface to the side surface of the housing with maximum contact plane to ensure the greatest heat transfer from the coupling to the housing, the housing is provided with interconnected longitudinal channel and a side opening aligned with the side opening of the coupling, A fitting and a non-return valve with a filter are located in the longitudinal channel of the housing, while the non-return valve provides gas bleeding when the pressure in the annulus exceeds the pressure in the tubing string by 0.1-0.2 MPa, and due to the minimum hydraulic resistance of the device, reduction in flow during fluid circulation by no more than 5-10%.

The features of the invention are:

1) a coupling with a lateral hole connected at both ends to the tubing;

2) the connection of the coupling side surface with the side surface of the housing;

3) the same with fit on the maximum plane to ensure the greatest heat transfer from the coupling to the housing;

4) interconnected longitudinal channel and side hole in the housing;

5) the combination of the side hole of the housing with the side hole of the coupling;

6) the location in the longitudinal channel of the nozzle body and check valve with a filter;

7) the use of a check valve that provides gas bleeding when the pressure in the annulus exceeds the pressure in the tubing string by 0.1-0.2 MPa;

8) due to the minimum hydraulic resistance of the device, ensuring a decrease in flow rate during fluid circulation by no more than 5-10%.

Sign 1 is common with the prototype, signs 2-8 are the salient features of the invention.

SUMMARY OF THE INVENTION

When operating an oil well in the annulus, i.e. gas accumulates in the space between the well casing and the tubing string. Gas as a lighter hydrocarbon fraction fills the upper wellhead. A large accumulation of gas is a negative phenomenon. In the upper part of the well, gas is passed into the tubing string and sent with the produced oil to the flow line. With a large pressure difference in the annulus and the tubing string during gas bypass and expansion, the wellhead part of the well is intensively cooled. In winter, cooling is aggravated by low air temperatures and heat loss in the soil frozen to the depth of freezing. All this can lead to freezing of the wellhead zone, especially during the production of highly watered oil. In the proposed invention solves the problem of improving the health of the well and devices in the estuary zone in winter under conditions of exposure to negative temperatures. The problem is solved by the device shown in figures 1 and 2.

The tubing 1 and 2 are connected by a sleeve 3 to a side hole 4. The sleeve 3 is connected by a side surface 5 to a side surface 6 of the housing 7. The housing 7 is provided with a longitudinal channel 8 and a side hole 9 connected to one another, aligned with the side hole 4 of the sleeve 3. A fitting 10 and a non-return valve 11 with a filter 12 are located in the longitudinal channel 8 of the housing 7. The non-return valve 11 ensures that the gas is vented when the pressure in the annulus 13 exceeds the pressure in the tubing string 1 and 2 by 0.1-0.2 MPa . Due to the minimum hydraulic resistance of the device, the flow rate is reduced by not more than 5-10% during fluid circulation.

The device operates as follows.

When the pressure in the annulus 13 exceeds the pressure in the column of tubing 1 and 2 by 0.1-0.2 MPa, the check valve 11 opens and gas flows from the annulus 13 through the filter 12, the check valve 11, fitting 10, longitudinal channel 8, side hole 9, side hole 4 into the inner space of the sleeve 3 and the inner space of the tubing 1 and 2. Next, the gas together with the produced products (oil) is sent to the flow line of the well.

A heated fluid passes through the tubing string 1 and 2, warming the sleeve 3, and through it the housing 7 and valve 11. This eliminates freezing and failure of the entire device. The connection of the side surface 5 of the coupling 3 with the side surface 6 of the housing 7 contributes to a more complete heat transfer and heating of the housing 7. Providing gas bleeding when the pressure in the annulus 13 is higher than the pressure in the string of tubing 1 and 2 by 0.1-0.2 MPa helps minimize gas expansion and the effect of lowering the temperature due to this effect. When the fluid circulates through the tubing string 1 and 2 and the annular space 13, the device provides minimal loss of fluid flow by 5-10% due to the minimum hydraulic resistance of the device.

The application of the proposed device will improve the efficiency of the device in the winter under the influence of negative temperatures.

Claims (1)

A device for transferring gas from the annulus to the tubing string, including a coupling with a lateral hole connected at both ends to the tubing, characterized in that the coupling is connected by the lateral surface to the lateral surface of the housing with the fit on the maximum plane to ensure maximum transmission heat from the coupling to the housing, the housing is provided with a longitudinal channel and a side opening interconnected with one another, combined with the side opening of the coupling in the longitudinal housing of the housing a fitting and a non-return valve with a filter are located, while the non-return valve provides gas bleeding when the pressure in the annulus is higher than the pressure in the tubing string by 0.1-0.2 MPa, and due to the hydraulic resistance of the device, the flow rate is reduced during circulation liquids no more than 10%.

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