RU2351749C1 - Installation for intra-well transfer of water from lower reservoir into upper one (version) - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: group of inventions refers to oil extracting industry, particularly to systems of maintaining reservoir pressure. The essence of the invention by one of versions is as follows: the installation consists of production tubing, of a packer, and of an electro-immersed pump with electric engine, a cable and a case. According to the invention the case envelops only the electric engine and it is equipped with the cable sealing unit located in an input module of the pump and conjugated with under packer space via a tail piece. A reverse valve is installed at the output of the electro-immersed pump; the said pump communicates via the reverse valve with the production string made with apertures for water supply into annular space and an upper reservoir. Also a flow meter is assembled in the interval between the aperture and pump output. According to the second version an additional production string is installed inside the production string; the additional production string is made with nipple for movable connecting with a seat and for water supply via the string and two-channel coupling into annular space and an upper reservoir.

EFFECT: simplification of installation design and assembly and also prevention of a production string from corrosion effect of transferred water.

2 cl, 2 dwg

Description

The invention relates to the oil and gas industry, in particular to systems for maintaining reservoir pressure.

A well-known installation for downhole pumping of water from the lower reservoir to the upper one (see I.I. Andreev and others. Cross-well and downhole pumping of water in the reservoir pressure maintenance system. M., OJSC VNIIOENG, 2006, p. 107, Fig. 3.3.6 ), containing an “inverted” ESP, in which the motor is located above the pump, and a packer that separates the layers.

The disadvantages of the installation are the design complexity, the inability to ensure engine cooling at close placement of aquifers and reservoirs.

The closest in its technical essence to the proposed installation for downhole pumping of water from the lower layer to the upper one (see I.I. Andreev et al. Inter-well and downhole pumping of water in the reservoir pressure maintenance system. M., JSC VNIIOENG, 2006, p. 107, Fig.3.3.a), containing a packer separating aquifers and reservoirs, a column of elevator pipes and an electric submersible pump placed in a casing.

The disadvantages of the installation are the difficulty of assembling an electric submersible pump at the well, large metal consumption, the possibility of gas accumulation above the pump intake, which impairs its operation, water injection through the production casing, leading to its corrosion.

The technical problems solved by the proposed installation are to simplify the design and its assembly, to protect the production string from corrosion.

This problem is solved by the proposed installation for downhole pumping of water from the lower layer to the upper, containing the main column of elevator pipes, a packer, an electric submersible pump with an electric motor, cable and casing.

What is new is that the casing covers only the electric motor, is equipped with a cable sealing unit, which is located in the inlet module of the pump and communicates with the under-packer space through the shank, and a check valve is installed at the outlet of the electric-submersible pump, through which it is connected to the column of elevator pipes made with a hole to supply water to the annulus and the upper reservoir, while a flow meter is installed in the gap between the hole and the pump outlet.

This problem is also solved by installing for downhole pumping of water from the lower layer to the upper one, containing the main column of elevator pipes, a packer, an electric submersible pump with an electric motor, cable and casing.

What is new is that the casing covers only the electric motor, is equipped with a cable sealing unit, which is located in the inlet module of the pump and communicates with the under-packer space through the shank, and a check valve is installed at the outlet of the electric-submersible pump through which it communicates with the column of elevator pipes having a two-channel coupling and a seat, while inside the column of elevator pipes there is an additional column of elevator pipes made with a nipple for movable connection with the seat and water supply through it and vuhkanalnuyu sleeve into the annulus and the upper layer.

The essence of the invention lies in the fact that only an electric motor of an electric submersible pump is enclosed in a casing. And the liquid is returned to the reservoir after measuring the flow rate at the mouth by an additional lift column or, in general, is not raised to the mouth, but is pumped through the hole in the main lift column, measuring the liquid flow rate by a flow meter installed in the gap between the pump and the hole.

Figure 1 shows the installation with an additional elevator column.

Figure 2 shows the installation with a hole in the main elevator column.

The installation (see Fig. 1) contains a production casing 1 of a well with a packer 2 separating the lower (aquifer) 3 and upper (productive) 4 formations and connected by a shank 5 with a casing 6 covering the electric motor 7 of the electric submersible pump 8 and closing at the input node 9 The pump 8 through the check valve 10 is connected to the main lift column 11, equipped with a sleeve 12 with channels 13 and 14 and a seat 15 for movable sealed connection with an additional lift column 16, which is located inside the main 11 and is equipped with a nipple 17 for the movable connection with the seat 15 of the sleeve 12. This connection of the sleeve 12 and the nipple 17 can be threaded, using a shaped groove or, for example, using a connection from an insert rod pump (not shown). The upper end of the additional elevator column 16 is connected to a two-channel wellhead valve 18, on which a pressure gauge 19 and a flow meter 20 are installed (shown conventionally).

The electric motor 7 is equipped with a pressure sensor 21, and power is supplied to it via a cable 22 having a sealed input into the casing 6 in the input node 9.

In the single-lift version (see FIG. 2), the main elevator column 11 is made with a hole 23, and a flow meter 24 is installed between it and the pump 8, lowered, for example, on a wireline cable 25.

The installation works as follows.

To install the installation, first lower the packer 2 on the shank 5 on the main elevator column 11 with the sleeve 12, the casing 6 with the electric motor 7, the pump 8 and cable 22. Then, after the packer 2 is planted and the wellhead fittings 18 are mounted, the additional elevator column 16 is lowered until the nipple 17 enters in the seat 15. Then complete the installation of the wellhead 18 and actuate the pump 8.

The pump 8 pumps liquid from the aquifer 3 (see FIG. 1) located under the packer 2 installed in the production casing 1, through the shank 5 into the cavity of the casing 6 and then to the inlet 9 of the pump 8, driven by an electric motor 7, fed through a cable 22, hermetically inserted into the casing 6 through the inlet 9. The pump 8 pumps liquid into the main lift column 11, which passes through the channel 13 of the coupling 12, the annular gap between the main 11 and the additional 16 lift columns, the wellhead 18 and enters the cavity of the additional lift 16. From this column through a channel 14 in the sleeve 12 and the annular space enters the reservoir 4. The pressure and volume of fluid injection into the reservoir 4 is measured manometer 19 and flow meter 20 mounted on the wellhead 18.

For the operation of a single-lift installation (see Fig. 2), the same equipment is lowered onto the main lift column 11 with a hole 23 using conventional single-channel wellhead fittings. In this case, the cavity of the main elevator column 11 is closed by a valve and a pressure gauge 19 is installed.

In the gap between the hole 23 and the pump 8, a flow meter 24 is installed, which can be constant and transmitting a signal, for example, along the supply core of cable 22 (not shown) or periodically lowered on the wireline 25.

In this installation, the fluid pumped by the pump 8 through the hole 23 and the annulus is fed into the reservoir 4.

In this case, the injection pressure is controlled by the wellhead pressure gauge 19, and the injection volume by the flowmeter 24 is stationary or periodically released on the wireline 25. In this case, the injected water immediately after the opening 23 enters the reservoir 4 without affecting the production string 1 along its entire length.

The non-return valve 10 prevents the backflow of fluid when the pump stops, and the pressure sensor 21 will ensure optimal operating conditions of the pump 8 and reservoir 3.

Thus, the present invention allows to simplify the design of the installation and its assembly, as well as to protect the production string from the corrosive effects of the pumped water.

Claims (2)

1. Installation for downhole pumping of water from the lower layer to the upper one, containing a column of elevator pipes, a packer, an electric submersible pump with an electric motor, cable and a casing, characterized in that the casing covers only the electric motor, is equipped with a cable sealing unit that is located in the pump input module and communicated with the under-packer space through the shank, and a check valve is installed at the outlet of the electric submersible pump, through which the said pump is able to communicate with the column of elevator pipes made with a hole for supplying water to the annulus and the upper layer, while a flow meter is installed between the hole and the pump outlet. 2. Installation for downhole pumping of water from the lower layer to the upper one, containing a column of elevator pipes, a packer, an electric submersible pump with an electric motor, cable and a casing, characterized in that the casing covers only the electric motor, is equipped with a cable sealing unit, which is located in the pump input module and communicated with the under-packer space through the shank, and a check valve is installed at the outlet of the electric submersible pump, through which the said pump is able to communicate with the column of elevator pipes having two a channel coupling and a seat, while inside the column of elevator pipes there is an additional column of elevator pipes made with a nipple for movable connection with the seat and water supply through it and a two-channel coupling into the annular space and the upper layer.

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