NO325707B1 - Gas powered pumping device and method for pumping a liquid into a well - Google Patents

Abstract

Gas-powered pumping device (2) and method for downhole pumping a liquid (34) from at least one liquid source (28) in a well (4) to at least one receiving area (16) for the liquid (34). The pump device (2) comprises a pressure manipulation chamber (18) with a lower chamber portion (38) and an upper chamber portion (40), the pressure manipulation chamber (18) being connected in flow to: - a liquid supply channel (42) connecting the pressure manipulation chamber (18) to the liquid source ( 28), and which includes a first one-way valve (50) for liquid flow only to the pressure manipulation chamber (18); - a liquid outlet duct (44) connecting the lower chamber portion (38) of the pressure manipulation chamber (18) to the liquid receiving area (16), and including a second one-way valve (52) for liquid flow only from the pressure manipulation chamber (18); - a gas supply duct (46) connecting the pressure manipulation chamber (18) to a gas source (54) with pressurized manipulation gas (56), and including a first control valve (58) for selectively introducing manipulation gas (56) and regulating the gas (56) thereof pressure (Pkammer); and - a gas outlet passage (48) leading out of the upper chamber portion (40) of the pressure manipulation chamber (18), and which includes a second control valve (60) for selectively discharging manipulation gas (56) and regulating the gas pressure (P chamber). By alternately lowering and increasing the gas pressure (P chamber), liquid (34) is pumped from the liquid source (28) to the receiving area (16) via the pressure manipulation chamber (18).

Description

GAS-DRIVEN PUMPING DEVICE AND METHOD FOR PUMPING A LIQUID IN A WELL

Field of the invention

This invention relates to a gas-driven pump device and a method for being able to pump a liquid, for example water and/or oil, out of a well or within the well. The liquid can consist of water or oil that comes from an underground production formation connected to the well. The liquid can also consist of a secreted liquid, for example aqueous liquid, which comes from a downhole separator associated with such a production formation.

The invention can advantageously be used in connection with downhole separation of oil and water from a hydrocarbon and aqueous production stream, where aqueous liquid is simultaneously injected into an underground deposition formation.

The invention can also be used in all types of wells, including awiks wells and horizontal wells.

The background of the invention

The invention has its background in an industrial need for a simple, reliable and cost-effective pump solution for use down a well.

Known technique and disadvantages with this

The prior art includes many types of conventional and submersible pump devices for use in a well, including piston pumps, displacement pumps, turbine pumps, centrifugal pumps, etc. Such conventional pump devices also include gas-driven pump devices. As a specialist in the field will be familiar with such pumps, a further description is considered unnecessary.

In this context, however, the following patent publications are mentioned as examples of known downhole pump devices: - US 6,929,064 Bl; - US 7,093,661 B2; - WO 2004/081341 A1; - WO 03/031815 A2; - NO 320,870 Bl; in - JP 10266972; - US 2006/0225886 Al; - US 5,536,147; and - US 5,058,669.

Common to such conventional downhole pumping devices is that they usually have relatively complicated constructions,

and/or that they have many moving parts. In addition, they usually receive mechanical, hydraulic, pneumatic or electric drive from the surface, which requires suitable connections

devices and equipment to provide the driving force. They are also usually extensive and/or complicated to operate, inspect and maintain. This usually means that they have a limited lifespan and/or a limited area of application, particularly in deep wells. This is usually reflected in operational and cost disadvantages.

There is thus a need in the industry for a substantially simpler, more operationally reliable and more cost-effective pump solution

which is also applicable under a number of different well conditions, including in deep wells with high pressure and high temperature.

Purpose of the invention

The purpose of the invention is to avoid or significantly reduce

disadvantages of the known technique by providing a new pump device and method for pumping liquid in a well.

How the purpose is achieved

The purpose is achieved through features that are stated in the following description and in the subsequent patent claims.

Furthermore, the invention assumes that a specialist in the field

i will make use of relevant knowledge in the area, including various known well technology and well equipment, and to the extent necessary to adapt the invention to the relevant well conditions and needs. Such known well equipment may include

suitable well seals, valves, control equipment, miscellaneous

in types of pipes, cables and materials, etc. This will not be discussed in more detail either, as this is considered known to the person skilled in the art.

According to a first aspect of the invention, a gas-driven pump device is provided for pumping a liquid from at least one liquid source in a well to at least one receiving area for the liquid, the liquid source having a pressure (Pkiide) and the receiving area having a pressure (Preceiver) is placed in the well.

The peculiarity of the pump device is that it comprises at least one pressure manipulation chamber which extends in the longitudinal direction of the well, and which includes a lower chamber part and an upper chamber part; and

- where said pressure manipulation chamber is connected flow-wise with the following channels: - at least one liquid supply channel which connects the pressure manipulation chamber with said liquid source, where the liquid supply channel includes at least one first one-way valve which allows liquid flow only to the pressure manipulation chamber; - at least one liquid outlet channel that connects the lower chamber part of the pressure manipulation chamber with said liquid receiving area, where the liquid outlet channel includes at least one second one-way valve that allows liquid flow only from the pressure manipulation chamber; - at least one gas supply channel connecting the pressure manipulation chamber with at least one gas source containing a

pressurized manipulation gas, where the gas supply channel includes at least one first control valve which is arranged for the selective introduction of manipulation gas into the pressure manipulation chamber as well as regulation of the gas's pressure (Pchamber) therein; and

- at least one gas outlet channel leading out of the upper chamber part of the pressure manipulation chamber, where the gas outlet channel

i includes at least one second control valve which is arranged for the selective discharge of manipulation gas from the pressure manipulation chamber as well as regulation of the gas's pressure (Pchamber) therein.

Thereby, the pump device is designed to be able to lead manipulation gas out of the pressure manipulation chamber as well as lower the gas pressure (P chamber) therein to a lower pressure (Pnedre) at which a resulting pressure difference (Pkiide-Pnedre) will drive the liquid from the liquid source and into the pressure manipulation chamber via the liquid supply channel. Thereby, the pump device is also arranged to then be able to lead manipulation gas into the pressure manipulation chamber and increase the gas pressure (Pchamber) therein to an upper pressure (PØVre) at which a resulting pressure difference (Pøvre-Preceiver) will drive the liquid from the pressure manipulation chamber to the receiver area via said liquid - outlet channel. In this way, the pump device is designed to be able to alternately lower and increase the gas pressure (Pchamber) in the pressure manipulation chamber, which process represents one operating cycle, in order to thereby be able to pump liquid from the liquid source to the receiving area via the pressure manipulation chamber.

The present pump device is thus based on being able to change the gas pressure (Pchamber) in the pressure manipulation chamber within a large pressure range, and preferably within several tens of bars. This is achieved by said gas source being pressurized to an appropriate pressure level which is at least capable of effecting the relevant upper pressure (PÖVRE) pressure manipulation chamber. The gas source can thus be arranged with such an appropriate pressure level, or a gas source can be selected which is at least pressurized to such a pressure level.

The pressure manipulation chamber can, if necessary, be several

hundred meters long and can hold a significant volume of gas and liquid.

In addition, said supply channels and outlet channels from the pressure manipulation chamber can for example be made up of suitable pipes, hoses or annulus between well pipes, possibly annulus between a well pipe and a well wall.

The pump device can also make use of suitable sensors, valve means and control devices for appropriate control of the gas and liquid flow into and out of the pressure manipulation chamber, but also for appropriate control of the liquid level in the pressure manipulation chamber during the aforementioned operating cycle. One or more water level stop devices and gas flow control devices can thus be used for this purpose. Such equipment is otherwise considered prior art and will therefore not be discussed in detail.

Said water level stop device can for example comprise one or more floats, float seats and known sensors that can distinguish a liquid from a gas at one or more water levels in the pressure manipulation chamber. Such sensors can distinguish differences in physical properties of the liquid and gas, for example differences in pressure, density, temperature, resistivity, acoustic travel time, optical properties and the like.

As an addition or alternative, said gas flow control device can, for example, be connected to known devices and sensors that can distinguish different properties in a liquid and/or gas at one or more water levels in

the pressure manipulation chamber. The gas flow control device is then arranged to be able to register such differences and/or characteristics and, on the basis of this, will be able to control said flow of the overpressure manipulation gas to and from the pressure manipulation chamber. Said sensors can, for example,

discern differences in pressure, density, temperature, resistivity, acoustic travel time, optical properties and the like.

Furthermore, said manipulation gas can consist of any suitable gas, for example a hydrocarbon gas, air, carbon dioxide or nitrogen.

In one embodiment, said liquid supply channel is connected flow-wise with at least one water production formation which is connected to the well, and which thereby constitutes said liquid source; while said liquid outlet channel is connected flow-wise with the surface of the well, which thereby constitutes the receiving area for water from the water production formation.

Thereby, the pump device in question can be used, for example, to pump and produce water from an underground water reservoir, for example a groundwater body. Such a water reservoir usually contains hydrostatically pressurized water, which usually means that the water will not flow to the surface by itself.

In another embodiment, said liquid supply channel is connected flow-wise with at least one oil production formation which is connected to the well, and which thereby constitutes said liquid source;

while said liquid outlet channel is connected flow-wise with the surface of the well, which thereby constitutes the receiving area for oil from the oil production formation.

Thereby, the pump device in question can be used, for example, to pump and produce oil from an underground oil reservoir. The pump device in question can thus replace a so-called nodding pump, which comprises a downhole oscillating piston pump which, via a long pump rod to the surface, is connected to a mechanical drive device on the surface.

In the two preceding embodiments, said gas outlet channel can comprise at least one gas draining channel which is filled with manipulation gas for the selective emission of so-called lifting gas in said liquid outlet channel, whereby a gas pressure gradient will exist in the gas draining channel, while a liquid pressure gradient will exist in the liquid outlet channel; - where the gas-filled gas tapping channel flow-wise connects the upper chamber part of the pressure manipulation chamber with a shallower depth level in the liquid outlet channel where the liquid (ie water or oil) has a liquid pressure (PgrUnnere); and - where said shallower depth level is selected at a depth where the liquid pressure (Pshallower) / via the gas pressure gradient in the gas tapping channel, will cause said lower gas pressure (Plower) in the pressure manipulation chamber, the lower gas pressure (Plower) will be substantially less than a corresponding liquid pressure at the same level in the liquid outlet channel.

Thereby, the difference between the density of the manipulation gas and the liquid flow is utilized to provide the lower gas pressure (Pnedre) in the pressure manipulation chamber. Thereby, the pump device is also designed to be able to selectively lead manipulation gas into the liquid outlet channel as lifting gas for the liquid (i.e. water or oil).

In this context, said gas source can consist of at least one

of the following gas sources:

; - a gas source on the surface; and

- a gas source in an underground formation.

A further embodiment will now be described which is specifically aimed at downhole separation and injection of water

which is separated from a hydrocarbon and aqueous production stream from an underground reservoir.

According to this embodiment, said liquid supply channel is connected flow-wise with an aqueous liquid in at least one hydrocarbon-water separator which is arranged in the well, the separator forming said liquid source;

- where said separator is connected flow-wise with a hydrocarbon- and water-containing production stream from at least one production formation that is connected to the well; - where the separator is designed to at least be able to separate said production stream into said water-containing liquid and into a hydrocarbon-containing liquid; - where the hydrocarbon-containing liquid in the separator is connected flow-wise with at least one production channel for the production of the hydrocarbon-containing liquid; and - where said liquid outlet channel is connected flow-wise with at least one deposition formation which is connected to the well, and which constitutes said receiving area for separated, water-containing liquid from the separator.

The expressions aqueous liquid and hydrocarbon-containing liquid do not presuppose 100% presence of water and hydrocarbons, respectively, but refer here to main components of water and hydrocarbons respectively.

Otherwise, the hydrocarbon-containing part of the production stream may contain only hydrocarbon liquid, possibly a mixture of hydrocarbon liquid and hydrocarbon gas.

Said deposition formation is preferably porous and permeable, but it can also be non-porous and impermeable. In order to be able to pump and inject the secreted and aqueous liquid into the deposition formation, the fluid pressure in the pores of the deposition formation (the pore pressure) and/or the formation's fracture stress (the fracturing pressure) must be overcome. This ratio must be factored in when the aforementioned upper gas pressure (Pavre) in the pressure manipulation chamber is to be determined.

In this embodiment, which is aimed at the production of both hydrocarbons and water, said gas outlet channel may comprise at least one gas tapping channel which is filled with manipulation gas for the selective emission of lifting gas in said production channel, whereby a gas pressure gradient will exist in the gas tapping channel, while a liquid pressure gradient will exist in the production channel; - where the gas-filled gas tapping channel flow-wise connects the upper chamber part of the pressure manipulation chamber with a shallower depth level in the production channel where the hydrocarbon-containing liquid has a liquid pressure (P shallower); and - where said shallower depth level is selected at a depth where the liquid pressure (P shallower) in via gas pressure gradient in the gas tapping channel will cause said lower gas pressure (Plower) in the pressure manipulation chamber, as the lower gas pressure (Plower) will be significantly less than a corresponding liquid pressure at the same level in the production channel.

Thereby, the difference between the density of the manipulation gas and the hydrocarbon-containing liquid is used to produce the lower gas pressure (Pnedre) in the pressure manipulation chamber. Thereby, the pump device is also designed to conduct selectively

manipulation gas into the production channel as lift gas for in the hydrocarbon-containing liquid.

In this context, said gas source can be made up of at least one of the following gas sources: - a gas source on the surface;

- a gas source in an underground formation; and

i - a gas source in the form of gas separated from it

hydrocarbon- and water-containing production flow from said production formation.

Said at least one hydrocarbon-water separator may comprise at least one cyclone separator. US 5,711,374 (corresponds to WO 94/13930) and US 5,296,153 (corresponds to WO 94/18432) describe cyclone separators which can be used in connection with the invention in question. Both of these publications describe the injection of secreted water into an underground disposal formation. However, the water injection takes place with the help of conventional downhole pumps which are covered by the known technique, i.a. the pump types mentioned above.

As an addition or alternative, said at least one hydrocarbon-water separator can also comprise at least one gravity separator. US 6,092,599 (corresponds to WO 99/15755) describes a downhole oil-water separation system which can be used in connection with the invention in question, and which is based on gravity separation of a hydrocarbon-containing production stream. This separation system is shown used in a vertical well. Conventional downhole pumps are used to pro-

in sprinklers secreted water to the surface, or to inject the water into an underground disposal formation.

If the well is a so-called horizontal well, the gravity separator can consist of a horizontal gravity separator which is arranged in a horizontal part of the well, and which can be several hundred meters long. If necessary, the horizontal well can also include several horizontal gravity separators. US 6,277,286 (corresponds to WO 98/41304) describes a horizontal gravity separator which can be used in

connection with the invention in question. Also this public

i tion describes the use of conventional downhole pumps

to inject secreted water into an underground deposition formation, possibly via a side step well.

If necessary, the at least one hydrocarbon-water separator can also comprise at least one gas separation device for separating gas from said production stream. US 6,691,781 describes a horizontal gravity separator for separating both gas, water and oil from a production stream. This type of separator can also be used in connection with the invention in question. The publication describes i.a. injection of secreted gas and/or water into an underground disposal formation. Here too, conventional downhole pumps are used for pumping separated liquid, while a turbine-driven gas compressor is used for pumping separated gas.

Furthermore, the pressure manipulation chamber can be arranged at a distance from the at least one separator. If necessary or desirable, the pressure manipulation chamber can be arranged several hundred meters from said separator. This follows from the fact that the pump device in question is designed to be able to change the gas pressure (Pchamber) in the pressure manipulation chamber within a large pressure range, whereby a correspondingly large pressure head (and lift height) is achieved for the pump device. This feature gives the pump device in question a significant advantage over known suction pumps, which are based on creating a negative pressure in relation to an ambient pressure, which is usually atmospheric

in air pressure. Such a suction pump will therefore be able to produce a driving pressure difference limited upwards to approx. 1 bar on the pump's inlet side, which corresponds to a maximum pressure head (and lift head) of approx. 10 m, depending on the density of the liquid

to be pumped. For this reason, suction pumps are not applicable in most wells. This applies to others as well

types of pumps with such a limited pressure head (and lift height).

Furthermore, said at least one deposition formation may lie shallower and/or deeper than the at least one production formation. As an addition or alternative, the at least one deposition formation may comprise at least one deposition layer in the at least one production formation, for example an aqueous layer underlying a hydrocarbon-containing layer of the same formation.

The pressure manipulation chamber can also have different designs. Thus, the pressure manipulation chamber can be arranged in or outside a pipe in the well, for example a production pipe, casing or coiled pipe. The pressure manipulation chamber

can also be arranged in an annulus in the well, for example between two well pipes or between a well pipe and a well wall.

The pumping device in question can advantageously comprise at least two pressure manipulation chambers which are designed for cooperative pumping of liquid from said liquid source and up to said

receiver area;

i - where said pressure manipulation chambers are arranged with a phase-shifted operating cycle in relation to each other, whereby a more efficient suction and pumping of liquid is achieved.

If the pump device is provided with two cooperating pressure manipulation chambers, the chambers can be arranged with the opposite operating cycle in relation to each other. The pump device may optionally include several such pairs with cooperating pressure manipulation chambers.

According to another aspect of the invention, a method is provided for pumping a liquid from at least one liquid source in a well to at least one receiving area for the liquid, the liquid source having a pressure (Pkiide) and the receiving area having a pressure (Preceiver) •

The peculiarity of the procedure is that it includes:

- to arrange at least one gas-driven pump device in the well, where the pump device comprises at least one pressure manipulation chamber which extends in the longitudinal direction of the well, and which includes a lower chamber part and an upper chamber part, and where said pressure manipulation chamber is connected flow-wise with the following channels: - at least one liquid supply channel which connecting the pressure manipulation chamber to said fluid source, wherein the fluid supply channel includes at least one first one-way valve that allows fluid flow only to the pressure manipulation chamber; - at least one liquid outlet channel that connects the lower chamber part of the pressure manipulation chamber with said liquid receiving area, where the liquid outlet channel includes at least one second one-way valve that allows liquid flow only from the pressure manipulation chamber; - at least one gas supply channel which connects the pressure manipulation chamber with at least one gas source containing a pressurized manipulation gas, where the gas supply channel includes at least one first control valve which is arranged for the selective introduction of manipulation gas into the pressure manipulation chamber as well as regulation of the gas pressure (P chamber) therein; and - at least one gas outlet channel that leads out of the upper chamber part of the pressure manipulation chamber, where the gas outlet channel includes at least one second control valve that is designed for selective discharge of manipulation gas from the pressure manipulation chamber as well as regulation of the gas pressure (P chamber) therein.

The procedure also includes the following steps:

(A) directing manipulation gas out of the pressure manipulation chamber as well as lowering the gas pressure (Pchamber) therein to a lower pressure (Pnedre) at which a resulting pressure difference (Pkiide-Pnedre) drives the liquid from the liquid source into the pressure manipulation chamber via the liquid supply channel; (B) filling the liquid up to an upper liquid level in the pressure manipulation chamber; (C) directing manipulation gas into the pressure manipulation chamber and increasing the gas pressure (Pchamber) therein to an upper pressure (Pøvre) at which a resulting pressure difference (PØVre-Preceiver) drives the liquid from the pressure manipulation chamber to the receiver area via said liquid outlet channel; (D) driving the liquid down to a lower liquid level in the pressure manipulation chamber; and (E) repeating steps (A)-(D), the course of which represents one operating cycle, thereby maintaining the pumping of liquid

from the liquid source up to the receiver area via the pressure manipulation chamber.

The above comments regarding constructive features of the pump device according to the first aspect of the invention also apply to the pump device according to the method in question.

In one embodiment of the method, this also includes the following steps: - connecting said liquid supply channel flow-wise with at least one water production formation which is connected to the well, and which thereby constitutes said liquid source; and - to flow-wise connect said liquid outlet channel with the surface of the well, which thereby constitutes the receiving area for water from the water production formation.

In another embodiment of the method, this also includes the following steps: - connecting said liquid supply channel flow-wise with at least one oil production formation which is connected to the well, and which thereby constitutes said liquid source; and - to flow-wise connect said liquid outlet channel with the surface of the well, which thereby constitutes the receiving area for oil from the oil production formation.

Furthermore, the method may include the following steps:

- to use a gas outlet channel comprising at least one gas tapping channel which is filled with manipulation gas for selective discharge of lifting gas in said liquid outlet channel, whereby a gas pressure gradient exists in the gas tapping channel, while a liquid pressure gradient exists in the liquid outlet channel; - by means of said gas draining channel, to flow-wise connect the upper chamber part of the pressure manipulation chamber with a shallower depth level in the liquid outlet channel where the liquid (i.e. water or oil) has a liquid pressure (P shallower); and - to select said shallower depth level at a depth where the liquid pressure (P shallower) # via the gas pressure gradient in the gas tapping channel, causes said lower gas pressure (Pnder) in the pressure manipulation chamber, the lower gas pressure (Pnder) being substantially less than a corresponding liquid pressure at the same level in the liquid outlet channel .

Thereby, the difference between the density of the manipulation gas and the liquid is utilized to provide the lower gas pressure (Pnedre) in the pressure manipulation chamber. Thereby, the pump device is also designed to selectively lead manipulation gas into

the liquid outlet channel as lifting gas for the liquid (i.e. water or in oil).

In this context, said gas source can be made up of at least one of the following gas sources:

- a gas source on the surface; and

- a gas source in an underground formation.

The method may also be directed specifically to the downhole separation and injection of water secreted from a hydrocarbon and aqueous production stream from an underground reservoir.

Thus, the method can also include the following steps:

- connecting said liquid supply channel flow-wise with an aqueous liquid in at least one hydrocarbon-water separator which is arranged in the well, the separator forming said liquid source; - where said separator is connected flow-wise with a hydrocarbon and aqueous production stream from at least one production formation associated with the well; and - where the separator is arranged to at least be able to separate said production stream into said water-containing liquid and into a hydrocarbon-containing liquid; - connecting the hydrocarbon-containing liquid in the separator flow-wise with at least one production channel for the production of the hydrocarbon-containing liquid; and - to connect said liquid outlet channel flow-wise with at least one deposition formation that is connected to the well, and

which constitutes said receiving area for separated, aqueous liquid from the separator.

This method embodiment can also include the following steps: - using a gas outlet channel comprising at least one gas tapping channel which is filled with manipulation gas for the selective emission of lifting gas in said production channel, whereby

in a gas pressure gradient exists in the gas withdrawal channel, while

a fluid pressure gradient exists in the production channel; - by means of said gas tapping channel, to flow-wise connect the upper chamber part of the pressure manipulation chamber with a shallower depth level in the production channel where the hydrocarbon-containing liquid has a liquid pressure (P shallower); and - to select said shallower depth level at a depth where the liquid pressure (Pshallower) / via the gas pressure gradient in the gas tapping channel, causes said lower gas pressure (Pnedre) in the pressure manipulation chamber, the lower gas pressure (Pnedre) being substantially less than a corresponding liquid pressure at the same level in the production channel .

Thereby, the difference between the density of the manipulation gas and the hydrocarbon-containing liquid is used to produce the lower gas pressure (Pnedre) in the pressure manipulation chamber. Thereby, the pump device is also designed to selectively lead manipulation gas into the production channel as lifting gas for the hydrocarbon-containing liquid.

In this context, said gas source can consist of at least one

of the following gas sources:

i - a gas source on the surface;

- a gas source in an underground formation; and

- a gas source in the form of gas that is separated from the hydrocarbon- and water-containing production stream from said production formation.

i Said at least one hydrocarbon-water separator may comprise at least one cyclone separator and/or at least one gravity separator.

If the well is a so-called horizontal well, the gravity separator can consist of a horizontal gravity separator which is arranged in a horizontal part of the well.

The at least one hydrocarbon-water separator can, if necessary, also comprise at least one gas separation device for separating gas from said production stream.

Furthermore, the pressure manipulation chamber can be arranged at a distance from at least one separator, and preferably several hundred meters from said separator, which is not possible with conventional suction pumps or the like.

As mentioned, said at least one deposition formation can lie shallower and/or deeper than the at least one production formation. As an addition or alternative, the at least one deposition formation may comprise at least one deposition layer in the at least one production formation.

The pressure manipulation chamber can also be arranged inside or outside

a pipe in the well, or it can be arranged in an annulus in the well.

The method can advantageously also include the following steps: - arranging at least two of said pump devices in the well, where each pump device includes at least one pressure manipulation chamber; i - to arrange the pumping devices for cooperative pumping of liquid from said liquid source up to said receiver area; and - aligning the pump devices with a phase-shifted operating cycle in relation to each other, whereby a more even suction ; and pumping of liquid is achieved.

Thus, at least two pump devices can be connected in parallel or in series, depending on the current need.

Advantages of the invention

This invention differs from the prior art in that it: - requires few equipment components; - requires few moving components; - provides a simple and reliable pumping device with a long service life; - can be used in new wells and in existing wells; - can be used both in vertical wells, horizontal wells and in horizontal wells; - can be used in pure water production wells or oil production wells that are not able to drive the production flow to the surface; - can be used in wells that produce a mixture of hydrocarbons and water, where the water is separated in a downhole separator and injected into an underground depositional formation/layer, while hydrocarbons are produced to the surface; - makes it possible to inject secreted water into a deposition formation/layer that is shallower and/or deeper than an associated production formation; and - can be used together with a gas lift system in the well.

Brief description of the drawing figures

In what follows, two non-limiting examples of the present invention are described and with reference to accompanying figures, where: Figures 1-6 show a first embodiment of the invention; and Figures 7-12 show a second embodiment of the invention. The attached figures are greatly simplified and show only the essential and symbolically indicated components of the invention. The components' designs, relative dimensions and relative positions are also marked. In what follows, similar, corresponding or corresponding details in the figures will be indicated largely with the same reference number.

Description of embodiments of the invention

Figures 1-6 show a first embodiment of a gas-powered pump device 2 placed in an underground well 4, which i.a. includes an outer casing 6 and an inner production pipe 8. Although the well 4 is shown as a vertical well in all figures 1-12, in practice it can also be an awiks well or a horizontal well. The casing 6 is provided with perforations 10, 12 situated opposite a production formation 14 and a shallower deposition formation 16, which has a pressure (Preceiver), and which forms a receiving area for liquid.

The pump device 2 comprises a pressure manipulation chamber 18

which is arranged in an annular space 19 in the well 4, and which can extend several hundred meters in the longitudinal direction of the well 4.

The pressure manipulation chamber 18 is delimited between the casing pipe 6 and the production pipe 8, and between a first (upper) well packing 20 and a second (lower) well packing 22. In this

embodiment, the second well packing 22 is arranged immediately

above the deposition formation 16, while a third well packing 24 is arranged immediately below the deposition formation 16. An injection annulus 26 is thereby defined between the second well packing 22 and the third well packing 24, and between the casing pipe 6 and the production pipe 8.

The production pipe 8 leads deeper down into the well 4 to an oil-water gravity separator 28, which is shown very schematically in all figures 1-12. The gravity separator 28 is connected i.a. with the production pipe 8, but it is also connected flow-wise with said production formation 14 via at least one inlet 30 in the separator 28, and via the perforations 10 in the casing pipe 6. From the production formation 14, an oil- and water-containing production stream 32 is led into the well 4 and further into the gravity separator 28, which has a pressure (Pkiide) • In the separator 28, which constitutes a liquid source for the pumping device 2, the production stream 32 is separated into a lower layer of water 34 and an upper layer of oil 36. In the relevant separator 28, the separation will proceed naturally because of. a density difference between water 34 and oil 36. Furthermore, the upper oil well is connected flow-wise with the production pipe 8 for the production of oil 36 to the surface of the well 4.

Although the separator 28 in all figures 1-12 is shown arranged in a vertical well, it can just as easily be arranged in a vertical well or in a horizontal well. In a horizontal well, the separator can be constituted by a horizontal gravity separator which is arranged in a horizontal part of the well. Other types of downhole separators can also be used, for example cyclone separators.

Furthermore, the pressure manipulation chamber 18, which includes a lower chamber portion 38 and an upper chamber portion 40, is fluidly connected with the following flow channels: a water supply pipe 42, a water outlet pipe 44, a gas supply pipe 46 and a gas outlet pipe 48.

Said water supply pipe 42 connects the pressure manipulation chamber 18 with the lower water layer 34 in the separator 28. The water supply pipe 42 is provided with a first one-way valve 50 which allows water flow only to the pressure manipulation chamber 18. The possible direction of flow is indicated by a black arrow in all figures 1-12. Furthermore, the pipe 42 is led in a pressure-sealing manner through said second and third well packing 22, 24.

Said water outlet pipe 44 connects the pressure manipulation chamber 18's lower chamber part 38 with said injection annulus 26,

which is connected flow-wise with said deposition formation 16 via the perforations 12 in the casing 6. The water outlet pipe 44 is provided with a second one-way valve 52 which allows water to flow only from the pressure manipulation chamber 18 into the injection annulus 26. The possible direction of flow is indicated by a black arrow on all figures 1-12. Furthermore, the pipe 44 is led in a pressure-sealing manner through said second well packing 22.

Otherwise, the aforementioned first and second one-way valves are 50, 52

preferably arranged so that they open at a specific pressure level that is adapted to the relevant well conditions and purpose.

Said gas supply pipe 46 connects the pressure manipulation chamber 18 with a gas source 54 containing a pressurized manipulation gas 56, which in the relevant embodiments consists of hydrocarbon gas. The gas source 54 is shown schematically in all figures 1-12. Alternatively, manipulation gas 56 can be supplied to the pressure manipulation chamber 18 directly from a pressurized

annulus 19 overlying said first well packing 20. The gas supply pipe 46 is provided with a first control valve 58

which is arranged for the selective introduction of manipulation gas 56 into the pressure manipulation chamber 18 as well as regulation of the gas 56's pressure (P chamber) therein. Any suitable valve means with associated lines, connections and regulating devices (not shown) can be used for this purpose. Furthermore, the pipe 46 is led in a pressure-sealing manner through the first well packing 20.

Said gas outlet pipe 48 leads out of the upper chamber part 40 of the pressure manipulation chamber 18 and directly into the production pipe 8. The gas outlet pipe 48 is provided with a second control valve 60 which is arranged for the selective release of manipulation gas 56 from the pressure manipulation chamber 18 as well as regulation of the gas 56's pressure ( Pkammer) therein. The manipulation gas 56 thereby functions as a lifting gas 56' for the oil 36 in the production pipe 8. Here, too, any suitable valve means with associated lines, connections and regulating devices (not shown) can be used for this purpose.

The method in question will now be described with reference to Figures 1-6. In all figures 1-12, the production flow 32, the flow of water 34 and the flow of oil 36 are indicated respectively with hatched arrows, white arrows and black arrows.

Figure 1 shows start-up of the pump device 2, where said first control valve 58 is open and manipulation gas 56 is led into the pressure manipulation chamber 18 via said gas supply pipe 46 to pressurize the chamber 18 to a gas pressure (P chamber) • The direction of gas flow is indicated by a black arrow at the gas supply pipe 46's expiry. The gas pressure (P chamber) is increased to a level close to the opening pressure for said second one-way valve 52 in the water outlet pipe 44, and to a level that exceeds the liquid pressure in the production pipe 8 vis-à-vis said second control valve 60.

The first control valve 58 is then closed, while the second control valve 60 is opened. Thereby, manipulation gas 56 is led out of the pressure manipulation chamber 18 via said gas outlet pipe 48 and lowers the gas pressure (Pchamber) in the chamber 18 to a lower pressure (Pnedre) whereby a resulting pressure difference (Pkiide - Pnedre) drives water 34 from the separator 28 and further into the pressure manipulation chamber 18 via the water supply pipe 42. At the same time, manipulation gas 56 is led into the production pipe 8 as a lifting gas 56' for the oil 36 that flows therein. The gas flow direction is indicated by a black arrow at the outlet of the gas outlet pipe 48. This is shown in Figure 2.

Figures 3 and 4 show two different stages during the filling of water 34 in the pressure manipulation chamber 18. The water 34 is filled up to an upper water level 62 in the pressure manipulation chamber 18, as the outflow of manipulation gas 56 decreases at the same time. This is shown in figure 4.

The second control valve 60 is then closed, while the first control valve 58 is opened. Thereby, pressurized manipulation gas 56 is led from the gas source 54 into the pressure manipulation chamber 18 and increases the gas pressure (Pchamber) therein to an upper pressure (PØVre)

at which a resulting pressure difference (Påvre-Preceiver)

drives water 34 from the pressure manipulation chamber 18 into the injection annulus 26 via the water outlet pipe 44. At the same time, the water 34 is driven further into the deposition formation 16 via the perforations 12 in the casing pipe 6. Figures 5 and 6 show two different stages during the emptying of water 34 from the pressure manipulation chamber 18. Using of the upper gas pressure (Pøvre) the water 34 is driven and emptied down to a lower water level 64

in the pressure manipulation chamber 18. The latter is shown in Figure 6. This process concludes an operating cycle for the pumping device 2. This operating cycle is illustrated in Figures 2-6 and is repeated to thereby maintain the pumping of water 34 from the separator 28 and further into the deposition formation 16 via bl .a. the pressure manipulation chamber 18.

Figures 7-12 show a second embodiment of a gas-driven pump device 2 according to the invention. This second embodiment includes most of the central elements from the first embodiment of the invention.

This embodiment, however, includes a pressure manipulation chamber 18 which is arranged as a separate unit outside said production pipe 8 and in said annulus 19 in the well 4.

A second difference is that the pressure manipulation chamber 18 is arranged at a distance from, and is shallower than, both the separator 28 and the deposition formation 16.

A third difference is that said gas outlet pipe 48 is now replaced by a gas tapping pipe 48' which is filled with manipulation gas 56 for the selective emission of lifting gas 56' in the production pipe 8. There will thereby be a gas pressure gradient in the gas tapping pipe 48', while a oil pressure gradient will exist in the production pipe 8. Similar to the previous embodiment, the gas-filled gas withdrawal pipe 48' is also provided with a second control valve 60 for selective discharge of manipulation gas 56 as well as regulation of the gas pressure (P chamber) in the pressure manipulation chamber 18. In addition, gas withdrawal -pipe 48' provided with a third one-way valve 66 which allows gas flow only from the pressure manipulation chamber 18. The possible direction of gas flow is indicated by a black arrow in all figures 7-12. The gas drain pipe 48' connects the upper chamber part 40 of the pressure manipulation chamber 18 flow-wise with a shallower depth level 68 in the production pipe 8 where the oil 36 has an oil pressure (P shallower) •

As an alternative (not shown), both a gas outlet pipe 48 and a gas drain pipe 48' can be used which are each provided with a control valve 60.

This shallower depth level 68 is selected at a depth where the oil pressure (Pshallower) / via the gas pressure gradient in the gas tapping pipe 48', will cause said lower gas pressure (Plower) in the pressure manipulation chamber 18. The gas pressure (Plower) will be substantially less than a corresponding oil pressure at the same level in the production pipe 8. Thereby, the difference between the densities of the manipulation gas 56 and the oil 36 is utilized to provide the lower gas pressure (Pnedre) in the pressure manipulation chamber 18. Thereby, this pump device 2 is also arranged to be able to selectively lead manipulation gas 56 into the production pipe 8 as lifting gas 56' for the flow of oil 36 from the separator 28.

Claims (40)

1. Gas-driven pump device (2) for pumping a liquid from at least one liquid source in a well (4) to at least one receiving area for the liquid, the liquid source having a pressure (Pkiide) and the receiving area having a pressure (Preceiver) # - where the pumping device ( 2) is placed in the well (4), characterized in that the pump device (2) comprises at least one pressure manipulation chamber (18) which extends in the longitudinal direction of the well (4), and which includes a lower chamber part (38) and an upper chamber part (40) ); and - that said pressure manipulation chamber (18) is connected flow-wise with the following channels: - at least one liquid supply channel (42) which connects the pressure manipulation chamber (18) with said liquid source, where the liquid supply channel (42) includes at least one first one-way valve (50) which allows liquid flow only to the pressure manipulation chamber (18); - at least one liquid outlet channel (44) which connects the lower chamber part (38) of the pressure manipulation chamber (18) with said liquid receiving area, where the liquid outlet channel (44) includes at least one second one-way valve (52) which allows liquid flow only from the pressure manipulation chamber (18); - at least one gas supply channel (46) which connects the pressure manipulation chamber (18) with at least one gas source (54) containing a pressurized manipulation gas (56), where the gas supply channel (46) includes at least one first control valve (58) which is arranged for the selective introduction of manipulation gas ( 56) in the pressure manipulation chamber (18) as well as regulation of the gas (56)'s pressure (Pchamber) therein; And - at least one gas outlet channel (48) which leads out of the upper chamber part (40) of the pressure manipulation chamber (18), where the gas outlet channel (48) includes at least one second control valve (60) which is arranged for the selective release of manipulation gas (56) from the pressure manipulation chamber ( 18) as well as regulation of the gas (56)'s pressure (<P>chamber) therein; - whereby the pump device (2) is designed to be able to lead manipulation gas (56) out of the pressure manipulation chamber (18) as well as to lower the gas pressure (Pchamber) therein to a lower pressure (Pnedre) at which a resulting pressure difference (Pkiide-Pnedre) will drive the liquid from the fluid source and into the pressure manipulation chamber (18) via the fluid supply channel (42); - whereby the pump device (2) is also arranged to then be able to lead manipulation gas (56) into the pressure manipulation chamber (18) and increase the gas pressure (Pchamber) therein to an upper pressure (Pøvre) at which a resulting pressure difference (PØVre-Preceiver) will drive the liquid from the pressure manipulation chamber (18) to the receiving area via said liquid outlet channel (44); and - whereby the pump device (2) is arranged to be able to alternately lower and increase the gas pressure (P chamber) in the pressure manipulation chamber (18), which sequence represents one operating cycle, in order to thereby be able to pump liquid from the liquid source to the receiving area via the pressure manipulation chamber (18). 2. Gas-driven pump device (2) according to claim 1, characterized in that said liquid supply channel (42) is connected flow-wise with at least one water production formation which is connected to the well (4), and which thereby constitutes said liquid source; and - that said liquid outlet channel (44) is connected flow-wise with the surface of the well (4), which thereby constitutes the receiving area for water from the water production formation. 3. Gas-driven pump device (2) according to claim 1, characterized in that said liquid supply channel (42) is connected flow-wise with at least one oil production formation which is connected to the well (4), and which thereby constitutes said liquid source; and - that said fluid outlet channel (44) is connected flow-wise with the surface of the well (4), which thereby constitutes the receiving area for oil from the oil production formation. 4. Gas-driven pump device (2) according to claim 2 or 3, characterized in that said gas outlet channel (48) comprises at least one gas drain channel (48') which is filled with manipulation gas (56) for selective discharge of lifting gas (56') in said liquid outlet channel (44), whereby a gas pressure gradient will exist in the gas withdrawal channel (48'), while a liquid pressure gradient will exist in the liquid outlet channel (44); - that the gas-filled gas drainage channel (48') flow-wise connects the upper chamber part (40) of the pressure manipulation chamber (18) with a shallower depth level (68) in the liquid outlet channel (44) where the liquid has a liquid pressure (Pshallower) # And - that said shallower depth level (68) is chosen at a depth where the liquid pressure (PgrUnnere) / via the gas pressure gradient in the gas tapping channel (48'), will cause said lower gas pressure (Pnder) in the pressure manipulation chamber (18), as the lower gas pressure (Pnder) will be significantly less than a corresponding liquid pressure at the same level in the liquid outlet channel (44); - whereby the difference between the densities of the manipulation gas (56) and the liquid flow is utilized to produce the lower gas pressure (Pnedre) in the pressure manipulation chamber (18); and - whereby the pump device (2) is arranged to be able to selectively lead manipulation gas (56) into the liquid outlet channel (44) as lifting gas (56') for the liquid. 5. Gas-driven pump device (2) according to any one of claims 1-4, characterized in that said gas source (54) consists of at least one of the following gas sources: - a gas source on the surface; and - a gas source in an underground formation. 6. Gas-driven pump device (2) according to claim 1, characterized in that said liquid supply channel (42) is connected flow-wise with an aqueous liquid (34) in at least one hydrocarbon-water separator (28) which is arranged in the well (4), wherein the separator (28) constitutes said liquid source; - that said separator (28) is connected flow-wise with a hydrocarbon and water-containing production stream (32) from at least one production formation (14) which is connected to the well (4); - that the separator (28) is designed to at least be able to separate said production stream (32) into said water-containing liquid (34) and into a hydrocarbon-containing liquid (36); - that the hydrocarbon-containing liquid (36) in the separator (28) is connected flow-wise with at least one production channel (8) for the production of the hydrocarbon-containing liquid (36); and - that said liquid outlet channel (44) is connected flow-wise with at least one deposition formation (16) which is connected to the well (4), and which constitutes said receiving area for separated, aqueous liquid (34) from the separator (28). 7. Gas-driven pump device (2) according to claim 6, characterized in that said gas outlet channel (48) comprises at least one gas drain channel (48') which is filled with manipulation gas (56) for selective discharge of lifting gas (56') in said production channel (8) , whereby a gas pressure gradient will exist in the gas withdrawal channel (48'), while a liquid pressure gradient will exist in the production channel (8); - that the gas-filled gas tapping channel (48') flow-wise connects the upper chamber part (40) of the pressure manipulation chamber (18) with a shallower depth level (68) in the production channel (8) where the hydrocarbon-containing liquid (36) has a liquid pressure (P shallower); and - that said shallower depth level (68) is selected at a depth where the liquid pressure (Pshallower) in via the gas pressure gradient in the gas tapping channel (48'), will cause said lower gas pressure (Plower) in the pressure manipulation chamber (18), as the lower gas pressure (Plower) will be significantly less than a corresponding liquid pressure at the same level in the production channel (8); - whereby the difference between the densities of the manipulation gas (56) and the hydrocarbon-containing liquid (36) is utilized to provide the lower gas pressure (Pnedre) in the pressure manipulation chamber (18); and - whereby the pump device (2) is arranged to be able to selectively lead manipulation gas (56) into the production channel (8) as lifting gas (56') for the hydrocarbon-containing liquid (36). 8. Gas-driven pump device (2) according to claim 6 or 7, characterized in that said gas source (54) consists of at least one of the following gas sources: - a gas source on the surface; - a gas source in an underground formation; and - a gas source in the form of gas separated from the hydrocarbon and water-containing production stream (32) from said production formation (14). 9. Gas-driven pump device (2) according to claim 6, 7 or 8, characterized in that said at least one hydrocarbon-water separator (28) comprises at least one cyclone separator. 10. Gas-driven pump device (2) according to any one of claims 6-9, characterized in that said at least one hydrocarbon-water separator (28) comprises at least one gravity separator. 11. Gas-driven pump device (2) according to claim 10, characterized in that the gravity separator consists of a horizontal gravity separator which is arranged in a horizontal part of the well (4). 12. Gas-driven pump device (2) according to any one of claims 6-11, characterized in that the pressure manipulation chamber (18) is arranged at a distance from the at least one separator (28). 13. Gas-driven pump device (2) according to any one of claims 6-12, characterized in that at least one deposition formation (16) lies shallower than the production formation (14). 14. Gas-driven pump device (2) according to any one of claims 6-13, characterized in that at least one deposition formation (16) lies deeper than the production formation (14). 15. Gas-driven pump device (2) according to any one of claims 6-14, characterized in that the at least one deposition formation (16) comprises at least one deposition layer in the production formation (14). 16. Gas-driven pump device (2) according to any one of claims 1-15, characterized in that the pressure manipulation chamber (18) is arranged in a pipe in the well (4). 17. Gas-driven pump device (2) according to any one of claims 1-15, characterized in that the pressure manipulation chamber (18) is arranged outside a pipe (8) in the well (4). 18. Gas-driven pump device (2) according to any one of claims 1-15, characterized in that the pressure manipulation chamber (18) is arranged in an annular space (19) in the well (4). 19. Gas-driven pump device (2) according to any one of claims 1-18, characterized in that the pump device (2) comprises at least two pressure manipulation chambers (18) which are arranged for cooperative pumping of liquid from said liquid source and up to said receiver area; and - that said pressure manipulation chambers (18) are arranged with a phase-shifted operating cycle in relation to each other, whereby a more efficient suction and pumping of liquid is achieved. 20. Method for pumping a liquid from at least one liquid source in a well (4) to at least one receiving area for the liquid, the liquid source having a pressure (Pkiide) and the receiving area having a pressure (Preceiver), characterized in that the method comprises: - to arrange at least one gas-driven pump device (2) in the well (4), where the pump device (2) comprises at least one pressure manipulation chamber (18) which extends in the longitudinal direction of the well (4), and which includes a lower chamber part (38) and an upper chamber part (40), and where said pressure manipulation chamber (18) is connected flow-wise with the following channels: - at least one liquid supply channel (42) which connects the pressure manipulation chamber (18) with said liquid source, where the liquid supply channel (42) includes at least one first one-way valve (50) allowing fluid flow only to the pressure manipulation chamber (18); - at least one liquid outlet channel (44) which connects the lower chamber part (38) of the pressure manipulation chamber (18) with said liquid receiving area, where the liquid outlet channel (44) includes at least one second one-way valve (52) which allows liquid flow only from the pressure manipulation chamber (18); - at least one gas supply channel (46) which connects the pressure manipulation chamber (18) with at least one gas source (54) containing a pressurized manipulation gas (56), where the gas supply channel (46) includes at least one first control valve (58) which is arranged for the selective introduction of manipulation gas ( 56) in the pressure manipulation chamber (18) as well as regulation of the gas (56)'s pressure (Pchamber) therein; And - at least one gas outlet channel (48) which leads out of the upper chamber part (40) of the pressure manipulation chamber (18), where the gas outlet channel (48) includes at least one second control valve (60) which is arranged for the selective discharge of manipulation gas (56) from the pressure manipulation chamber ( 18) as well as regulation of the gas (56)'s pressure (<P>chamber) therein; And that the method further comprises the following steps: (A) directing manipulation gas (56) out of the pressure manipulation chamber (18) as well as lowering the gas pressure (Pchamber) therein to a lower pressure (Pnedre) at which a resulting pressure difference (Pkiide-Pnedre) drives the liquid from the liquid source and into the pressure manipulation chamber (18) via the liquid supply channel (42); (B) filling the liquid up to an upper liquid level in the pressure manipulation chamber (18); (C) directing manipulation gas (56) into the pressure manipulation chamber (18) and increasing the gas pressure (Pchamber) therein to an upper pressure (PØVre) at which a resulting pressure difference (PeVre-Preceiver) drives the liquid from the pressure manipulation chamber (18) to the receiving area via said liquid outlet channel (44); (D) driving the liquid down to a lower liquid level in the pressure manipulation chamber (18); and (E) repeating steps (A)-(D), which course represents one operating cycle, thereby maintaining the pumping of fluid from the fluid source to the receiving area via the pressure manipulation chamber (18). 21. Method according to claim 20, characterized in that the method also comprises: - connecting said liquid supply channel (42) flow-wise with at least one water production formation which is connected to the well (4), and which thereby constitutes said liquid source; and - to connect said liquid outlet channel (44) flow-wise with the surface of the well (4), which thereby forms the receiving area for water from the water production formation. 22. Method according to claim 20, characterized in that the method also comprises: - connecting said liquid supply channel (42) flow-wise with at least one oil production formation which is connected to the well (4), and which thereby constitutes said liquid source; and - to connect said fluid outlet channel (44) flow-wise with the surface of the well (4), which thereby constitutes the receiving area for oil from the oil production formation. 23. Method according to claim 21 or 22, characterized in that the method also comprises: - using a gas outlet channel (48) comprising at least one gas draining channel (48') which is filled with manipulation gas (56) for selective discharge of lifting gas (56') in said liquid outlet channel (44), whereby a gas pressure gradient exists in the gas tapping channel (48'), while a liquid pressure gradient exists in the liquid outlet channel (44); - by means of said gas drain channel (48'), to flow-wise connect the upper chamber part (40) of the pressure manipulation chamber (18) with a shallower depth level (68) in the liquid outlet channel (44) where the liquid has a liquid pressure (P shallower) / And - to select said shallower depth level (68) at a depth where the liquid pressure (P shallower) # via the gas pressure gradient in the gas tapping channel (48'), causes said lower gas pressure (Plower) in the pressure manipulation chamber (18), the lower gas pressure (Plower) being substantially less than a corresponding liquid pressure at the same level in the liquid outlet channel (44); - whereby the difference between the densities of the manipulation gas (56) and the liquid is utilized to produce the lower gas pressure (Pnedre) in the pressure manipulation chamber (18); and - whereby the pump device (2) is arranged to selectively lead manipulation gas (56) into the liquid outlet channel (44) as lifting gas (56') for the liquid. 24. Method according to any one of claims 20-23, characterized in that said gas source (54) consists of at least one of the following gas sources: - a gas source on the surface; and - a gas source in an underground formation. 25. Method according to claim 20, characterized in that the method also comprises: - connecting said liquid supply channel (42) flow-wise with an aqueous liquid (34) in at least one hydrocarbon-water separator (28) which is arranged in the well (4) ), as the separator constitutes said liquid source; - where said separator (28) is connected flow-wise with a hydrocarbon and water-containing production stream (32) from at least one production formation (14) which is connected to the well (4); and - where the separator (28) is arranged to at least be able to separate said production stream (32) into said water-containing liquid (34) and into a hydrocarbon-containing liquid (36); - connecting the hydrocarbon-containing liquid (36) in the separator (28) flow-wise with at least one production channel (8) for the production of the hydrocarbon-containing liquid (36); and - to connect said liquid outlet channel (44) flow-wise with at least one deposition formation (16) which is connected to the well (4), and which constitutes said receiving area for separated, aqueous liquid (34) from the separator (28). 26. Method according to claim 25, characterized in that the method also comprises: - using a gas outlet channel (48) comprising at least one gas drain channel (48') which is filled with manipulation gas (56) for the selective discharge of lifting gas (56') in said production channel ( 8), whereby a gas pressure gradient exists in the gas tapping channel (48'), while a liquid pressure gradient exists in the production channel (8); - by means of said gas drain channel (48'), to flow-wise connect the upper chamber part (40) of the pressure manipulation chamber (18) with a shallower depth level (68) in the production channel (8) where the hydrocarbon-containing liquid (36) has a liquid pressure (P shallower); and - to select said shallower depth level (68) at a depth where the liquid pressure (P shallower) in via the gas pressure gradient in the gas tapping channel (48'), causes said lower gas pressure (Plower) in the pressure manipulation chamber (18), the lower gas pressure (Plower) being substantial less than a corresponding fluid pressure at the same level in the production channel (8); - whereby the difference between the densities of the manipulation gas (56) and the hydrocarbon-containing liquid (36) is utilized to provide the lower gas pressure (Pnedre) in the pressure manipulation chamber (18); and - whereby the pump device (2) is arranged to selectively lead manipulation gas (56) into the production channel (8) as lifting gas (56') for the hydrocarbon-containing liquid (36). 27. Method according to claim 25 or 26, characterized in that said gas source (54) consists of at least one of the following gas sources: - a gas source on the surface; - a gas source in an underground formation; and - a gas source in the form of gas which is separated from the hydrocarbon and water-containing production stream (32) from said production formation (14). 28. Method according to claim 25, 26 or 27, characterized in that said at least one hydrocarbon-water separator (28) comprises at least one cyclone separator. 29. Method according to any one of claims 25-28, characterized in that said at least one hydrocarbon-water separator (28) comprises at least one gravity separator. 30. Method according to claim 29, characterized in that the gravity separator consists of a horizontal gravity separator which is arranged in a horizontal part of the well (4). 31. Method according to any one of claims 25-30, characterized in that the pressure manipulation chamber (18) is arranged at a distance from the at least one separator (28). 32. Method according to any one of claims 25-31, characterized in that at least one deposition formation (16) lies shallower than the production formation (14). 33. Method according to any one of claims 25-32, characterized in that at least one deposition formation (16) lies deeper than the production formation (14). 34. Method according to any one of claims 25-33, characterized in that the at least one deposition formation (16) comprises at least one deposition layer in the production formation (14). 35. Method according to any one of claims 20-34, characterized in that the pressure manipulation chamber (18) is arranged in a pipe in the well (4). 36. Method according to any one of claims 20-34, characterized in that the pressure manipulation chamber (18) is arranged outside a pipe (8) in the well (4). 37. Method according to any one of claims 20-34, characterized in that the pressure manipulation chamber (18) is arranged in an annulus (19) in the well (4). 38. Method according to any one of claims 20-37, characterized in that the method also comprises: - arranging at least two of said pump devices (2) in the well (4), where each pump device (2) includes at least one pressure manipulation chamber (18 ); - arranging the pump devices (2) for cooperative pumping of liquid from said liquid source up to said receiver area; and - aligning the pump devices (2) with a phase-shifted operating cycle in relation to each other, whereby a more uniform suction and pumping of liquid is achieved. 39. Method according to claim 37 or 38, characterized in that at least two pump devices (2) are connected in parallel. 40. Method according to claim 37 or 38, characterized in that at least two pump devices (2) are connected in series.