EA003112B1 - Downhole device for controlling fluid flow in a well - Google Patents

Abstract

1. A downhole device for controlling the flow of fluids through a perforation of a well casing in a hydrocarbon fluid production well, the device comprising a deformable chamber which contains a stimuli responsive gel, which gel has a volume that varies in response to variation of a selected physical stimulating parameter, providing closing off perforations in a well casing. 2. The device of claim 1, wherein the gel is an electromagnetic field responsive gel which releases water if an electromagnetic field of a certain field strength is exerted to the gel and which absorbs water in the absence of an electromagnetic field and wherein the device is equipped with an electromagnetic field transmitter which is adapted to exert an electromagnetic field of a selected field strength to the gel. 3. The device of claim 2, wherein the gel is selected from the group of polyacrylamide gels and polymethylacrylic acid gels. 4. The device of claim 1, wherein the gel is contained in a flexible bladder which seals off the fluid passage in response of a volume increase of at least part of the gel in the chamber. 5. The device of claim 4, wherein the flexible bladder has a toroidal shape and surrounds an orifice in a production liner in the inflow region of an oil and/or gas production well and wherein the gel in the flexible bladder is induced to swell so that the bladder seals off the orifice in response to the detection of influx of water into the well via the orifice. 6. The device of claim 4, wherein the flexible bladder has a toroidal shape and is arranged in an annular space between two co-axial production tubing sections of which the walls are perforated near one end of the annular space such that the perforations are closed off in response to a volume increase of at least part of the body of gel within the bladder and the perforations are opened in response to a volume decrease of at least part of the body of gel within the bladder. 7. The device of claim 5, wherein the flexible bladder comprises two segments which are separated by at least one bulkhead which is impermeable to the gel and which is at least temporarily permeable to water. 8. The device of claim 7, wherein said at least one bulkhead is made of a material which is permeable to water if an electromagnetic field is imposed on the bulkhead and which is impermeable to water if no electromagnetic field is exerted to the bulkhead. 9. The device of claim 8, wherein said at least one bulkhead separates two segments of the flexible bladder which each comprise a gel according to claim 2 or 3 and the device comprises one or more electromagnetic sources which are adapted to selectively impose an electromagnetic field on one of the segments of the chamber and/or the bulkhead. 10. The device of claim 7, wherein the flexible bladder comprises two gel-filled segments which are separated by a pair of gel impermeable bulkheads which are separated by an intermediate segment of the chamber which is filled with water.

Description

FIELD OF THE INVENTION

The invention relates to a downhole device for controlling fluid flow through a well for producing hydrocarbon feedstocks.

There are many devices for controlling fluid flow in a well. Typically, these devices comprise a valve body that opens or closes the passage of fluid in response to valve activation by an electric or hydraulic motor.

Since the fluid pressure and the pressure difference across the well valve are usually large, powerful electric or hydraulic motors are required that require significant space in a usually narrow well and the use of conduits to supply electrical or hydraulic power to a high power or high voltage or high voltage pressure.

The aim of the present invention is to provide a downhole fluid control device for use in a well for hydrocarbon production, which is compact and does not require the use of special channels for supplying high voltage or high pressure energy.

SUMMARY OF THE INVENTION

The downhole device according to the invention comprises a deformable chamber that contains a gel responsive to control influences, the gel having a volume that changes in response to a change in the selected physical impact parameter, and a fluid passage that closes in response to an increase in volume of at least at least parts of the gel and deformable chamber.

The gel is preferably a gel that responds to an electromagnetic field that releases water if the electromagnetic field acts on the gel with a certain field strength and which absorbs water in the absence of an electromagnetic field, and the device is equipped with electromagnetic field transmission means that is configured to act on the gel by electromagnetic field with the selected force.

Suitable gels that respond to an electromagnetic field are polyacrylamide gels and polymethylacrylic acid gels. Gels that respond to an electromagnetic field of this type are known from patents I8-A5100933, νθ-920-9202005 and 1P-A-2711119. These state-of-the-art sources indicate that gels that respond to electromagnetic fields can be used for various applications, such as microcapsules for dyes or drugs, sensors, actuators, converters, memory devices, and selective pumps.

Known applications are limited to surface equipment and are used in relatively small mechanical assemblies that operate under controlled environmental conditions.

However, it has been found that such gels can be used in a downhole fluid flow control device that operates in a well at high pressure and temperature. The gels can be actuated by means of an electromagnetic field, the intensity of which is from 0.5 to 50 V per centimeter of the length of the deformable chamber, so that the required energy is small compared to mechanical valves and can be easily generated by a battery located in the well, a galvanic cell, a power generator and / or transmitted along the wall of the borehole pipe.

The gel is preferably contained in an elastic balloon that blocks the fluid passage in response to an increase in the volume of at least a portion of the gel in the chamber.

The elastic balloon preferably has a toroidal shape and surrounds the hole in the production casing in the inlet of the well for oil and / or gas production, while swelling the gel in the elastic balloon so that the balloon closes the hole in response to detecting fluid flow through the hole.

As an alternative, the elastic balloon has a toroidal shape and is located in the annular space between two coaxial sections of the production string, the walls of which are perforated near one end of the annular space, so that the perforation closes in response to an increase in the volume of at least part of the gel volume inside the balloon and perforation opens in response to a decrease in the volume of at least a portion of the volume of the gel inside the balloon.

It should be noted that in publication XV O 97/0330 a drilling fluid formulation is disclosed, including non-polyampholytic polymers and gels that change their hydration state in response to environmental influences.

The known drilling fluid selectively blocks the pores of the rock outside the well, in contrast to this invention, which relates to a downhole flow control device that is located inside the wellbore.

Description of the preferred embodiment

The following is a detailed description of the invention with reference to the accompanying drawings, which depict the following:

FIG. 1A is a device according to the invention with a gel-filled balloon in an open position;

FIG. 1B shows the device of FIG. 1A, when the gel-filled balloon closes the fluid passage;

FIG. 2A is an alternative embodiment of the device according to the invention in the open position;

FIG. 2B - the device according to FIG. 2A in the closed position;

FIG. ZA is another alternative embodiment of the device according to the invention in the open position;

FIG. 3B - the device according to FIG. FOR in the closed position;

FIG. 4A and 4B are modifications of the device of FIG. ZA and ZV in a plan view and in isometric view;

FIG. 5 is a sectional view of the device of FIG. 4A and 4B in the well pipe;

FIG. 6 - well pipe according to FIG. 5, in which several devices according to the invention are installed in isometric view.

In FIG. 1A and 1B show a well 1 for producing oil and / or gas, which passes through a formation 2 carrying oil and / or gas.

The casing liner Z forms the liner of the wellbore, and the perforation 10 in the liner Z allows oil and / or gas to pass into the well 1 from the surrounding formation.

Inside the casing shank 3, sleeve 4 is removably fixed using a pair of inflatable packers 5.

The sleeve 4 contains an annular space 6, which is formed between the inner and outer walls 7 and 8 of the sleeve 4 and in the right part of the annular space 6, both the inner and outer walls of the sleeve have a perforation 9.

In the annular space 6 is located a gel-filled cylinder 11. The cylinder 11 contains two parts 11A and 11B, which are separated by a partition 12. The partition 12 is permeable to water, but impermeable to gel 1Z that responds to an electromagnetic field in the cylinder 11.

The sleeve 4 is equipped with a battery 14 and a block 15 for receiving and / or transmitting electric energy, which is configured to expose the electric field to the first or second parts 11A or 11B, respectively, of the balloon.

In FIG. 1A, an electromagnetic field acts on the first part 11A and the water contained in the gel 1Z is squeezed out of it through the baffle 12 into the second part 11B, in which the gel 1Z absorbs water. As a result, the cylinder 11 is pushed to the right side of the drawing and closes the perforation 9, so that the flow of fluid into the sleeve 4 is excluded. The pressure equalizing channels 17 allow free movement of the cylinder parts 11A and 11B in the annular space 6.

In FIG. 1B, an electromagnetic field acts on the second part 11B, and then water is squeezed out of the gel 1Z contained therein into the first part 11A, so that the balloon moves to the left and allows fluid to pass through the openings 9 and 10 from the formation 2 into the well 1.

In FIG. 2 shows a device substantially similar to that shown in FIG. 1, in which similar components are denoted by the same reference numbers, except that there are two water-permeable partitions 12A and 12B in the container, between which there is a body 16 to facilitate the flow of water between parts 11A and 11B.

In FIG. 2A, the device is shown in the open position, and in FIG. 2B - in the closed position.

In FIG. 3A and 3B show another embodiment of a downhole fluid flow control device according to the invention, which, as shown in FIG. 6, can be inserted into the hole of the well pipe.

In FIG. 3A shows the device Z0 in the open position, so that the fluid can flow into the well, as indicated by the arrow

31.

The device Z0 contains a disk-shaped housing Z2, in which there is a disk-shaped cavity ZZ.

The toroidal balloon Z4 is installed in the housing Z2, so that the central hole Z5 in the cylinder Z4 is on the same axis as the central passage Z6 for fluid in the housing

32. At the entrance of passage Z6, a sand-proof sieve Z7 is located to prevent sand and other solid particles from entering the well.

The cylinder Z4 is surrounded by a toroidal casing of foam material Z8, the pores of which are filled with water. The foam also contains cells or granules that are filled with expanding gas. The cylinder Z4 is filled with an electromagnetic field-responsive gel Z9 and has a cylindrical outer wall 40 that is permeable to water but impermeable to gel Z9.

An electric coil 41 is built into the body of foam material Z8. The coil 41 forms part of the electrical circuit 42, which contains an electric switch 43 and an electric source 44 in the form of a rechargeable battery. The battery can be charged by passing a low voltage electric current through the wall of the borehole pipe and / or using a downhole electric energy generator (not shown), which is driven by a small fan or turbine, which in turn is rotated by a fluid stream passing through the borehole.

In FIG. The switch 43 is open so that no electric current passes through the coil 41. As a result, the gel 39 is not affected by an electromagnetic field and the gel releases water, which seeps through the water-permeable outer wall 40 of the cylinder 34 and is absorbed by the material 38. This reduces the gel 39 so that the cylinder 34 is compressed in the direction of the cylindrical outer wall 40 and is created a central hole 35 through which fluid can flow into the well, as indicated by arrow 31.

In FIG. 3B, the switch 43 is closed so that the electric coil 41 acts by an electromagnetic field on the gel 39. As a result, the gel absorbs water from the foam 38 through the cylindrical outer wall 40 of the balloon 34. This causes the gel 39 to swell, so that the balloon 34 expands and thereby closes central passage 36 for the fluid.

The switch 43 can be connected to a sensor (not shown) located inside the well, which closes the switch if water inflow through the device is detected. The sensor may also form part of a sensor unit that controls several parameters and which is connected to a data processing unit that is programmed to optimize hydrocarbon production from the reservoir.

In FIG. 4A and 4B show an embodiment of the device according to the invention, in which the housing 50 has an oblong or elliptical shape. As shown in FIG. 4A, in this case, the gel filling the balloon 51 can be separated from the pair of bodies 52 from the foam filled with water material by a pair of permeable walls 53. The central passage for the fluid may have a cylindrical or elliptical shape and contain a sand screen 54, while in the housing 50 built-in electric coil (not shown).

In FIG. 5 shows a section through the device of FIG. 4A and 4B, which is inserted into the wall of the pipe 55 of the well. In FIG. 6 is a perspective view of the well pipe 55 of FIG. 5, in which a pair of inflow control devices shown in FIG. 4A, 4B and 5.

The housings 50 of the devices shown in FIG. 6 are oriented in the longitudinal direction with respect to the well pipe to provide a substantially flat shape of the bodies 50, which simplifies the manufacturing process.

It should be understood that the gel-filled balloon may have a permeable wall that is in contact with the fluid of the well and which allows the gel to absorb and release water from the fluid of the well and vice versa. In this case, the wall of the cylinder should be permeable to water, but impermeable to gel and produced oil and / or gas.

It should also be understood that the gel responsive to the electromagnetic field can be replaced by a gel responsive to other control actions, such as temperature, and that the cylinder can be replaced by another deformable chamber, such as a cylindrical chamber, in which the gel forces the piston to move up and down in response to a change in gel volume.

Claims (10)

CLAIM 1. Downhole device for controlling the flow of fluid through the perforation of the casing in the well during the extraction of hydrocarbons, containing a deformable chamber filled with gel, responsive to the control action and able to change its volume in response to changes in the selected physical effect parameter, while ensuring the perforations overlap in the casing. 2. The device according to claim 1, characterized in that the gel is a gel that reacts to an electromagnetic field, capable of emitting water when the gel is affected by an electromagnetic field of a given intensity, and absorb water in the absence of an electromagnetic field, while the device is equipped with an electromagnetic field emitter with the possibility of exposure to the gel electromagnetic field of a given intensity. 3. The device according to claim 2, characterized in that the gel is selected from the group of polyacrylamide gels or polymethyacrylic acid gels. 4. The device according to claim 1, characterized in that the gel is contained in an elastic cylinder, which is made with the possibility of sealing the perforation in response to an increase in the volume of at least part of the gel in the container. 5. The device according to claim 4, characterized in that the elastic cylinder has a toroidal shape and surrounds a hole in the production casing in the inflow zone for oil and / or gas production, while the gel in the elastic cylinder seals the hole in response to the detection of water inflow into the well through the hole. 6. The device according to claim 4, characterized in that the elastic cylinder has a toroidal shape and is located in the annular space between two coaxial sections of the production casing, the walls of which are perforated near one end of the annular space, so that the perforation closes in response to an increase in volume of at least at least part of the body of the gel inside the container and the perforation opens in response to a decrease in the volume of at least part of the body of the gel inside the container. 7. The device according to claim 5, characterized in that the elastic cylinder contains two parts, separated from one another by at least one partition, impermeable to the gel and at least temporarily permeable to water. 8. The device according to claim 7, characterized in that at least one partition is made of a material that is permeable to water when an electromagnetic field acts on the material of the partition, and which is impermeable to water when there is no effect of the electromagnetic field. 9. The device according to claim 8, characterized in that at least one partition separates two parts of an elastic balloon, each of which contains a gel according to claim 2 or 3, and the device contains one or more sources of electromagnetic field made with the possibility of selective exposure to an electromagnetic field on one of the parts of the chamber and / or partition. 10. The device according to claim 7, characterized in that the elastic balloon contains two gel-filled parts, which are separated by a pair of barrier-impermeable partitions, which, in turn, are separated by means of an intermediate section of the chamber filled with water.