RU2459930C1 - Downhole packer installation and device for gas extraction for it - Google Patents

Abstract

FIELD: oil and gas production.

SUBSTANCE: downhole packer installation includes packer, gas extraction device mounted in packer cavity coaxially to it. Gas extraction device is consists of two parts, lower and upper, the upper part is done with outer diameter equal to packer mandrel inner diameter, the lower part is done with outer diameter less than the inner diameter of packer mandrel and mounted with formation of longitudinal bypass channel between its outer surface and inner surface of packer mandrel, bottom end of gas extraction device lower part is equipped with the bead the diameter of outer surface of which is equal to the diameter of packer mandrel inner surface, the bead is located below the radial bypass channel of packer, the lower part of gas extraction device is separated from the upper part by upper radial bypass channel that connects its longitudinal bypass channel to upper part of packer cavity, the bottom end of gas extraction device upper part and top end of its lower part in the zone of upper radial bypass channel location are performed with formation of narrowing zone of gas extraction device cavity.

EFFECT: stable pump operation for fluid supply without operating mode breakdown, continuous gas extraction from annular space under packer above pump suction, simplification of gas extraction device structure, increase of processibility of downhole packer installation mounting and maintaining.

2 cl, 1 dwg

Description

The invention relates to downhole exploitation of hydrocarbon deposits and can be used in the design of a downhole packer installation for the extraction of fluid and gas outlet at the same time.

Known borehole packer installation, which includes a pump for extracting fluid lowered into a borehole on a pipe string and a packer dividing the insulated interval from the bottom of the pump intake (see the description of the invention to RF patent No. 2331758 "Well packer installation with a pump (options)", IPC E21B 3/00, published 08/20/2008., Option 5, Fig.14). In option 5 of the installation, the pipe string in its lower part, near the fluid pump, contains a bypass device with at least one radial channel connecting the annular space of the fluid pump with the longitudinal cavity of the pipe string. This installation also contains a pipe of smaller diameter located in the pipe string above the fluid pump, mounted coaxially with the pipe string, which is connected by the lower part of its internal cavity to the pump discharge and which forms longitudinal channels with the pipe string. The longitudinal channels are connected through the radial channels of the bypass device with the annulus. The upper part of the pipe of smaller diameter is connected to a device for gas removal - an ejector jet pump, which is made with a receiving chamber in the form of a nipple with a seating surface and with a working body with a nozzle, a mixing chamber and a diffuser. The receiving chamber of the ejector pump is connected through a longitudinal channel formed by a pipe of smaller diameter and a pipe string, and through the radial channels of the bypass device with the annulus.

When the pressure at the pump intake is lower than the saturation pressure, free gas is released from the fluid, which is removed from the space under the packer through the lower bypass device through its radial channels using a jet ejector pump. Otherwise, gas accumulating below the intake of the fluid pump can cause a sharp decrease in fluid withdrawal due to gas squeezing out the liquid level below the intake of the fluid pump. In the event of a breakdown or clogging of the jet pump, it must be removed, flushed and installed back, which may lead to the need to remove the packer and leads to additional labor costs and an increase in the time of well repair. If the jet pump is installed above the packer, then there is a problem of connecting the landing nipple of the jet pump to the packer so that the receiving nozzle of the jet pump nipple coincides with the gas outlet pipe. There is also the problem of installing the lower part of the pipe of a smaller diameter to ensure its exact tight connection with the bypass device. A poor pump fit or poor pipe installation will impair the reliability of connecting the mixing chamber of the jet pump mixing chamber to the under-annular annular space or the reliability of connecting a smaller diameter pipe to a bypass device, which will reduce the efficiency of gas extraction from the packer, and consequently, the efficiency of fluid extraction. Removing the jet pump located under the packer is an even more complicated procedure and is possible if the diameter of the flow section of the packer is larger than the overall dimensions of the pump itself. The problem of connecting the jet pump to the bypass device is also exacerbated. All this causes equipment downtime and leads to a decrease in the efficiency of the well, to additional labor costs, to increase the cost of hydrocarbon production.

A well-known downhole packer installation comprising a pipe string equipped with a bypass device with at least one radial channel and a longitudinal channel, a fluid supply pump and a packer that is lowered into the well on the pipe string and separates the insulated interval from the bottom of the pump intake (see description of the invention) to the patent of the Russian Federation No. 2331758 "Downhole packer installation with a pump (options)", IPC E21B 3/00, published on 08/20/2008., option 2, Fig. 8). The transfer device is located on the pipe string below the packer. A pipe of a smaller diameter, mounted concentrically or eccentrically, which is hermetically connected by the lower end to the transfer device, is lowered into the cavity of the pipe string. The upper end of the pipe of smaller diameter is connected to the wellhead equipment of the well for gas extraction or is located freely at a given height above the packer, hydraulically connected to the cavity of the pipe string. The functions of the device for the removal of gas performs a pipe of smaller diameter associated with the bypass device. This installation is the closest analogue. Its gas exhaust device is the closest analogue to the gas exhaust device in accordance with the invention.

The described design also does not remove the problem of accurately installing the lower part of the pipe of smaller diameter for hermetic connection with the bypass device. The design is complex, cumbersome, because through the longitudinal channel of the packer pass additional pipes of different diameters associated with the radial channels of the bypass devices. The operation of the packer of this design necessitates the installation of control valves, blind plugs, plugs, bypass circulation valves during operation, which further complicates both the design of the packer and its preparation for operation. Installing valves offset from the axis of the column using a special tool is a separate problem in itself.

The objective of the invention is to ensure the stable operation of the pump for supplying fluid without disruption of the operating mode, increasing the reliability of the downhole packer installation by providing constant gas removal from the annulus under the packer over the pump intake, simplifying the design of the gas exhaust device, improving the installation and maintenance of the downhole packer installation.

The problem is solved by the design of the downhole packer installation, including

- a string of tubing of a well,

- a packer made with a cavity, launched into the well on a pipe string, which separates the insulated interval from the bottom from the pump intake,

- a device for venting gas installed in the cavity of the packer coaxially with it,

- the device for venting gas includes interconnected at least one lower radial channel and at least one longitudinal channel of the bypass device - radial and longitudinal bypass channels for venting gas,

- the lower bypass radial channel connects the longitudinal channel of the gas exhaust device with the annulus of the well below the packer, ensuring the tightness of their joints, i.e. with sealing of mating surfaces,

- bypass longitudinal channel connects the output of the lower bypass radial channel with the upper part of the cavity of the packer, therefore, with the upper cavity of the pipe string,

- the upper end of the gas exhaust device is hydraulically connected to the cavity of the pipe string.

The difference between the invention in relation to the prototype is the following.

- the lower bypass radial channel is made not under the packer, but in the lower part of the packer,

- the gas exhaust device is made of two parts, lower and upper, both cylindrical,

- the cylindrical upper part of the gas exhaust device is made with an outer diameter equal to the inner diameter of the packer barrel, ensuring the tightness of the junction,

- the cylindrical lower part of the gas exhaust device is made with an outer diameter smaller than the inner diameter of the packer barrel,

- and installed with the formation between its outer cylindrical surface and the inner cylindrical surface of the barrel of the packer, at least one longitudinal bypass channel,

- the lower end of the lower part of the gas exhaust device is provided with a shoulder, the diameter of the lateral outer surface of which is equal to the diameter of the inner cylindrical surface of the barrel of the packer, ensuring the tightness of the junction,

- a gas exhaust device is installed in the packer so that the bead is located below the radial bypass channel of the packer,

- the lower part of the gas exhaust device is separated from its upper part by at least one upper radial bypass channel,

- the upper radial bypass channel of the gas exhaust device connects its longitudinal bypass channel to the upper part of the packer cavity,

- the lower end of the upper part of the gas exhaust device and the upper end of its lower part in the area of location (exit) of the upper radial bypass channel are made with a diameter of their inner surfaces less than the diameter of their inner surfaces with respect to their diameters in other parts, with the formation of a zone of narrowing of the cavity gas exhaust devices.

The problem is also solved by the design of a device for removing gas from the annulus through the longitudinal cavity of the packer to the well outlet, which contains:

- at least one longitudinal channel for gas bypass,

- the longitudinal channel of the gas exhaust device is hermetically connected with its lower end to the lower radial channel for gas bypass,

- the upper end of the gas exhaust device is hydraulically connected to the cavity of the pipe string.

The difference between the device for gas extraction in accordance with the invention with respect to the prototype is the following.

- the gas exhaust device is made of two parts, lower and upper, both cylindrical,

- the cylindrical upper part is made with an outer diameter equal to the inner diameter of the packer,

- the cylindrical lower part of the gas exhaust device is made with an outer diameter smaller than the outer diameter of the cylindrical upper part of the gas exhaust device, i.e. packer barrel inner diameter,

- the lower part of the gas exhaust device is separated from its upper part by at least one upper radial bypass channel, with the possibility of connecting the upper radial channel of the gas exhaust device with the cavity of the gas exhaust device, i.e. with the top of the packer cavity,

- the lower end of the lower part of the gas exhaust device is provided with a shoulder, the diameter of the lateral outer surface of which is equal to the outer diameter of the upper part of the gas exhaust device,

- the lower end of the upper part of the gas exhaust device and the upper end of its lower part in the area of location (exit) of the upper radial bypass channel are made with a diameter of their inner surfaces less than the corresponding diameter of the other parts with the formation of a narrowing zone (mixing chamber).

The figure shows a longitudinal section of a packer installation mounted on a string of tubing of a well containing a gas removal device. The arrows indicate the direction of fluid flows (arrows with tails) and exhaust gas flows (simple arrows).

The packer 1 is lowered on the casing string 2 of the well tubing below the insulated interval 3 from the intake of the fluid supply pump 4. In the lower part of the packer 1, a radial channel 5 is made - the lower radial channel for bypassing gas accumulated in the annulus 6. Packer 1 is installed on the column 2 of the well pipes, resting on the inner surface of the pipe of the production casing of the well with a centralizer 7, an anchor spot assembly 8, which is set on the cone 9 of the packer 1. The packer 1 is provided on its outside for sealing the insulated interval 3 with elastic elastic, for example rubber, cuffs 10 that interact with the stop 11. The packer 1 is made with a cavity 12. When Using electrocentrifugal pump 4 is provided with a fluid supply electrical cable disposed in the sealed cable duct 13 to the outside of the barrel 1. The packer apparatus 14 is installed in the gas discharge cavity packer 1 coaxially with it. The gas exhaust device 14 is made of two parts, the lower 15 and the upper 16, both parts are cylindrical. The cylindrical upper part 16 is made with an outer diameter equal to the inner diameter of the barrel of the packer 1, with the possibility of hermetically landing on the inner surface of the barrel of the packer 1. Such an installation of the upper part 16 of the device 14 gas removal can be carried out in the form of a fit of its sealing elements (rings) on a longitudinal landing seat either on the packer barrel, or using a locking assembly mounted on the outer diameter of the device 14 (not shown). The cylindrical lower part 15 of the gas exhaust device 14 is made with an outer diameter less than the inner diameter of the barrel of the packer 1, i.e. smaller than the outer diameter of the upper part 16, and mounted on the packer 1 with the formation between its outer cylindrical surface and the inner cylindrical surface of the barrel of the packer 1, at least one longitudinal (vertical) channel 17 or a single annular channel 17. The figure shows in cross section two vertical channel 17 or a single annular channel. The channel 17 can be made by making a groove, longitudinal or spiral, on the outer surface of the lower part of the insert and / or on the inner surface of the portion of the packer barrel located opposite the lower part 15 of the gas exhaust device 14, as with equal diameters of the lower part 15 and the packer barrel , and with the indicated diameter of the lower part 15 is less than the specified diameter of the barrel of the packer. The lower end of the lower part 14 of the device 14 of the gas outlet is provided with a shoulder 18 with a sealing connection of the device 14 with the packer 1 element, as shown in the figure. The diameter of the side outer surface of the shoulder 18 is equal to the diameter of the inner cylindrical surface of the barrel of the packer 1 for mounting the device 14 on the packer 1, i.e. the diameter of the outer surface of the upper part 16 of the gas exhaust device 14. The gas exhaust device 14 is installed in the packer 1 so that the flange 18 is located below the radial channel 5 of the packer 1 with sealing mating surfaces. In this case, the vertical channel 17 of the gas exhaust device 14 is in its lower part in communication with the lower radial bypass hole 5. The lower part 15 of the gas exhaust device 14 is separated from its upper part 16 by at least one upper radial bypass channel 19 made in the middle part the side surface of the device 14. The figure shows in cross section two upper radial bypass channels 19 or one annular. The upper radial bypass channel 19 of the gas exhaust device 14 connects the longitudinal bypass channel 17 to the upper part of the cavity 12 of the packer 1. The lower end of the upper part 16 of the gas exhaust device 14 and the upper end of its lower part 15 in the location (outlet) of the upper radial bypass channel 19 with diameters of their inner surfaces less than the diameters of their inner surfaces in other parts with the formation of a constriction zone 20 (mixing chamber) in the cavity of the gas exhaust device 14, i.e. in the cavity 12 of the packer 1. The internal dimensions and shape of the narrowing zone of the device are calculated, as well as the parameters of the wellhead equipment of the well for gas extraction, by computer simulation using engineering calculations for certain characteristics of the well. The number 21 indicates the pipe of the production casing of the well.

Downhole packer installation with a gas exhaust device operates as follows.

When pump 4 is operating to extract fluid, a decrease in pressure at the pump inlet below the saturation pressure may occur. Free gas is released from the fluid, which accumulates in the sub-packer zone 6 of the annulus. The pressure of the accumulated gas and the occurrence of a pressure drop at the location of the lower radial bypass channel 5 with respect to the pressure in the constriction zone 20 (mixing chamber) in the cavity of the gas exhaust device 14 causes the gas to penetrate into the lower radial bypass channel 5. differential pressure, the gas under pressure rises along the channel 17 between the outer diameter of the lower part 15 of the device 14 for gas removal and the inner diameter of the barrel of the packer 1 and enters the upper radial bypass channel 19 entering the mixing chamber 20. The difference in the geometric dimensions of the constriction chamber 20 and the upper radial bypass channel 19 creates a diffuser effect in the mixing chamber, in which the flow of gas passing through is slowed down / expanded, its pressure rises, and then the gas rushes to the outlet of the selection device 14 gas, expanding even more at its outlet and the output of the packer 1, falling into the cavity of the pipe string and further to the wellhead. In this case, the pump 4 continues to extract the fluid, the flow of which passing through the cavity 12 of the packer 1 and the mixing chamber 20 of the gas exhaust device 14 carries with it the flow of gas leaving the upper radial bypass channel 19. In this case, both the gas for the fluid and the fluid for gas perform the functions of a gas-lift medium, increasing the total joint flow and simplifying the flow of both fluid and gas at the wellhead.

Thus, the design of the gas exhaust device and the packer installation as a whole with such a device provide constant gas removal from the annulus under the packer, excluding the effect of gas on the fluid, squeezing it from pump 4, and thereby violating the operating mode of hydrocarbon recovery, ensure stable operation of the pump for supplying fluid, increasing production efficiency. The packer installation with the gas exhaust device has a simple design, their location relative to each other eliminates the problems inherent in the prototype, simplifies the operation of lifting the gas exhaust device in the event of clogging and reinstallation with a simple connection of the lower radial bypass channel, without dismantling the packer installation. The manufacturability of installation and maintenance of a downhole packer installation is increased, it becomes possible to quickly change the operating mode of the gas exhaust device by replacing the nozzle (diffusers) of the mixing chamber of the gas exhaust device.

Claims (2)

1. A downhole packer installation including a cavity packer, a gas exhaust device installed coaxially with the packer cavity, the gas exhaust device includes at least one lower radial channel and at least one longitudinal channel of the transfer device interconnected, the bypass longitudinal channel connects the output of the lower bypass radial channel with the upper part of the packer cavity, characterized in that the lower bypass radial channel is made in the lower part of the packer, the device Yes, the gas is made of two parts, the lower and upper, both are cylindrical in shape, the cylindrical upper part of the gas exhaust device is made with an external diameter equal to the inner diameter of the packer barrel, ensuring the tightness of the junction, the cylindrical lower part of the gas exhaust device is made with an external diameter less than the internal the diameter of the packer barrel and is installed with the formation between its outer cylindrical surface and the inner cylindrical surface of the packer barrel at least one product gas bypass channel, the lower end of the lower part of the gas exhaust device is equipped with a shoulder, the diameter of the lateral outer surface of which is equal to the diameter of the inner cylindrical surface of the barrel of the packer, ensuring the tightness of the junction, the gas removal device is installed in the packer so that the collar is located below the radial bypass channel packer, the lower part of the gas exhaust device is separated from its upper part by at least one upper radial bypass channel, the upper radial bypass A gas channel of the gas exhaust device connects its longitudinal bypass channel to the upper part of the packer cavity, the lower end of the upper part of the gas exhaust device and the upper end of its lower part in the location (outlet) of the upper radial bypass channel are formed to form a narrowing zone of the cavity of the gas exhaust device. 2. A gas exhaust device, characterized in that it is made of two parts, lower and upper, both cylindrical in shape, the cylindrical lower part of the gas exhaust device is made with an outer diameter smaller than the outer diameter of the cylindrical upper part of the gas exhaust device, the lower part of the gas exhaust device from its upper part by at least one upper radial bypass channel, the lower end of the lower part of the gas exhaust device is provided with a shoulder, the diameter of the lateral outer surface of which is equal to the outer Diameter of the upper part of the gas discharge device, the lower end of the upper portion of the gas discharge device and an upper end of the lower part of a location area (exit) of the upper radial passageway adapted to form a restriction zone.

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