RU2496971C1 - Automatic device for bypass of annular gas to tubing string - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: device includes a housing, a check ball valve, a hydraulic channel with a central constriction, a string of pump rods, which is equipped with a flow diverter, which is located in annular space above level of well fluid. Besides, the device has a branch pipe in axial line of a hydraulic channel, which attaches the tubing cavity before the flow diverter and the check ball valve protected with a hinged cap against mechanical impurities and equipped with a travel limiter of the protective cap. The device is arranged in the housing fixed on the tubing string, to the walls of which a large base of an isosceles triangular stop is adjacent, with a flow diverter supported from it through a radial thrust bearing in the form of a cylindrical thickening having running fit to the housing walls. Besides, diameter of a circle drawn through the triangle vertex is larger than diameter of the pump screw.

EFFECT: improving reliability and efficiency of an automatic device for bypass of annular gas.

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Description

The invention relates to the field of oil and gas industry and can be used to reduce excess gas pressure in the annulus of producing wells, mainly in wells operated by screw pump installations.

Provides increased reliability and efficiency of an automatic device for annular gas bypass in order to reduce annular pressure in wells operated by screw pump installations while simplifying the design of the device.

A known method of discharging gas from the annulus [RF Patent No. 2079636, EV 43/00, publ. 05/20/1997], which provides for the location of the check valve in the annulus.

The method is applicable only to wells operated by installations of electric centrifugal pumps, its use in wells operated by installations of screw pumps is impossible.

Closest to the proposed invention is an automatic valve device for transferring annular gas into tubing (tubing) [RF Patent No. 2318983, EV 43/00, publ. 03/10/2008], consisting of a non-return valve, a hydraulic channel with central narrowing, a string of pump rods equipped with a flow diverter, located in the annulus, in the coupling of the tubing string above the level of the well fluid.

However, the installation of a sealant on a string of pump rods is difficult, since the seal must be installed in such a way that it ensures their unhindered reciprocating movement. In addition, it is difficult to manufacture and install an annular check valve in the tubing coupling.

The objective of the invention is to increase the reliability and efficiency of an automatic device for bypass annulus gas in order to reduce annular pressure in wells operated by surface-driven screw pump installations while simplifying the design of the device.

The problem is solved by the proposed automatic device for transferring annular gas into the tubing string.

An automatic device for transferring annular gas into the tubing string contains a housing, a check ball valve, a hydraulic channel with central restriction, a column of sucker rods equipped with a flow diverter, located in the annulus above the level of the borehole fluid, has a pipe connecting the pump cavity in the axial line of the hydraulic channel -compressor pipes in front of the flow diverter and a non-return ball valve protected by a hinged cap from mechanical impurities and equipped with a stroke limiter. The device is placed in a housing mounted on a tubing string, to the walls of which there is a large base of an isosceles triangular stop with a flow diverter resting on it through an angular contact bearing in the form of a cylindrical thickening having a running fit to the walls of the housing, the diameter of a circle drawn through the apex of the triangle , larger diameter of the pump screw.

The design of the device is shown in figures 1 and 2.

In Fig.1, the design of the screw pump in the well with an automatic device for by-pass annulus gas into the tubing string.

Figure 2 presents an automatic device for bypass annulus gas into the tubing string.

Inside the housing 1 (see Fig. 2) there is a hydraulic channel B made with a central restriction connecting the cavity of the tubing 2 through the nozzle 3 located in the axial line with the annulus through the check ball valve 4, protected by a hinged cap 5 from mechanical impurities and equipped with a stroke limiter 6. During the descent of the device into the well, the hinge cap 5 of the check ball valve 4 is closed, after installation it opens under its own weight to the level of the stroke limiter 6. Rod string 7 made with a flow diverter 8 in the form of a cylindrical thickening having a landing fit to the walls of the device casing 1 and resting on an isosceles triangular stop 9 by means of an angular contact bearing 10 that does not interfere with the rotational movement of the rod string 7. The large base of the isosceles triangular stop 9 abuts against the walls of the casing 1, and the diameter of the circle drawn through the top of the triangle is larger than the diameter of the pump screw 11 (see figure 1).

Automatic device for transferring annular gas into the tubing string works as follows.

In the process of operation of the screw pump 11, due to a change in the direction of flow of the gas-liquid mixture by the flow diverter 8, the mixture through the pipe 3 enters the hydraulic channel B with a central narrowing. In the narrowing area, the pressure of the gas-liquid mixture is reduced due to the acceleration of its movement, as a result of which the high annular gas pressure opens the check ball valve 4 and the gas is bypassed into the tubing 2. When mixed, the annular gas and gas-liquid mixture pass through the hydraulic channel B into the tubing cavity 2 above the deflector stream 8.

After the gas bypass into the tubing cavity 2, the gas-liquid mixture in the tubing cavity 2 is lightened and, as a result, the energy consumed by the installation for raising the well production is reduced. Since there was a gas bypass from the annulus, the gas pressure drops and the check ball valve 4 closes again until the pressure increases, then the cycle repeats.

Using an automatic device for transferring annular gas into the tubing string allows reducing the gas pressure in the annular space regardless of the temperature conditions of the wells operated by the surface-mounted screw pump installations, increasing the liquid level above the pump, increasing the well flow rate, and avoiding the formation of hydrate plugs in the annular space by reducing gas pressure in the annulus.

Using an automatic device for transferring annular gas into the tubing string will reduce the depth of the pump suspension by increasing the liquid level in the annulus and thereby reduce the consumption of tubing, sucker rods and increase the overhaul period of the plants.

The technical and economic efficiency of an automatic device for transferring annular gas into the tubing string is to increase the efficiency of operation of wells operated by screw pump installations.

Claims (1)

An automatic device for transferring annular gas into the tubing string, comprising a housing, a check valve, a hydraulic channel with central restriction, a string of pump rods equipped with a flow diverter located in the annulus above the level of the well fluid, characterized in that the device has a hydraulic axial line the channel the pipe connecting the cavity of the tubing in front of the flow diverter and the check ball valve protected by a hinged cap from mechanical impurities is limited by a stroke limiter and placed in a housing fixed on a tubing string, to the walls of which there is a large base of an isosceles triangular stop, with a flow diverter resting on it through an angular contact bearing in the form of a cylindrical thickening having a landing fit to the walls of the housing, the circumference of which drawn through the top of the triangle, larger than the diameter of the pump screw.

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