CN1222679C - Downhole device for controlling fluid flow in a well - Google Patents

Abstract

A downhole device for controlling the flow of fluids through an oil and/or gas production well comprises a deformable chamber which contains an electromagnetic field or other stimuli responsive gel and a fluid passage which is closed off in response to a volume increase of the gel and the deformable chamber.

Description

Downhole device for controlling fluid flow in a wellbore

Background technique

The present invention relates to a downhole device for controlling the flow of fluids through a hydrocarbon fluid production well.

Various devices exist for controlling the flow of fluids within a wellbore. These devices basically consist of a valve body which opens or closes a fluid passage in response to activation of an electric or hydraulic motor.

Because the fluid pressure and the differential pressure across the downhole valve are usually high, high power electronic or hydraulic motors are required, which take up a lot of space in small boreholes and require high power and higher voltage or high voltage electronic or hydraulic power supply lines.

It is an object of the present invention to provide an apparatus for controlling downhole fluid control in hydrocarbon production wells which is compact and does not require higher voltage or high voltage power supply lines for operation.

Technical solutions

A downhole device according to the present invention includes: a deformable chamber containing an excitation-sensitive gel whose volume varies with selected physical excitation parameters; and a fluid flow channel that responds to the deformable The cavity, or at least a portion of the gel, increases in volume and closes.

As a preferred mode, the gel is an electromagnetic field sensitive gel, and if an electromagnetic field of a certain strength is applied to the gel, the gel releases water; and when there is no electromagnetic field, the gel absorbs water; wherein, the device assembly There is an electromagnetic field emitter adapted to apply an electromagnetic field of selected strength to the gel.

Suitable electromagnetic field sensitive gels include polyacrylamide and polymethylacrylic acid gels. This type of electromagnetic field sensitive gel is of the type in US Patent 5100933, International Application WO9202005 and Japanese Patent No. 2711119. The electromagnetic field-sensitive gels disclosed in these prior art can be useful in various applications, such as microcapsules of colorants or drugs, mechanical or chemical memories or switches, sensors, actuators, frequency converters, memories, controllable release systems and selection sex pump.

These known applications are limited to surface equipment and are suitable for smaller machines operating in controlled environments.

However, the applicant has surprisingly found that such a gel can be used in downhole flow control devices operating in high pressure and high temperature borehole environments. The gel can be excited by an electromagnetic field of 0.5-50 volts per centimeter of deformable cavity length, thus requiring less power than mechanical valves, and the magnetic field can be powered by downhole accumulators, batteries, generators and/or through wells Produced by tube wall transfer.

In a preferred manner, the gel is filled in a flexible bladder, which closes the liquid flow channel corresponding to the increase in volume of at least a portion of the gel in the deformable cavity.

As a suitable form, the flexible capsule is toroidal and surrounds an orifice of the production liner in the inflow zone of the oil and/or gas production well; wherein the gel in the flexible capsule can be induced and expand, thereby sealing the orifice in response to detecting water flowing through the orifice into the wellbore.

As another form, the flexible capsule is in the shape of a ring and is arranged in an annular space; There are openings at one end of the space so that the openings close corresponding to an increase in the volume of at least a portion of the gel within the capsule and open corresponding to a decrease in the volume of at least a portion of the gel within the capsule.

It has been observed that International Application WO97/0330 discloses a drilling composition comprising a non-polyampholite polymer and gel which change in response to environmental stimuli their hydration state.

In contrast to this known drilling composition which selectively seals off the pores of the formation around the wellbore and thus relates to treatment of the formation outside the wellbore, the present invention relates to a downhole fluid disposed within the wellbore control device.

best practice

The invention will be described in detail with reference to the accompanying drawings, which include:

Accompanying drawing 1A shows a device according to the present invention, wherein, a capsule filled with gel is in open position;

Figure 1B shows the device of Figure 1A, wherein a gel-filled capsule closes the fluid pathway;

Figure 2A shows a device according to another embodiment of the present invention, the device is in an open position;

Figure 2B shows the device of Figure 2A in the closed position;

Fig. 3 A shows the device according to another embodiment of the present invention, the device is in the open position;

Figure 3B shows the device of Figure 3A in the closed position;

Figures 4A and 4B are three-dimensional top views of the device in Figures 3A and 3B with slight modifications;

Figure 5 shows a schematic cross-sectional view of the device according to Figures 4A and 4B within an oil well tubular; and

Fig. 6 is a three-dimensional view of the oil well tubular of Fig. 5 incorporating a plurality of devices according to the invention.

Referring to Figures 1A and 1B, an oil and/or gas production well 1 is provided which traverses an oil and/or gas containing formation 2.

A liner 3 lines the wellbore; perforations 10 in the liner 3 allow oil and/or gas to flow into the wellbore 1 from the surrounding formation.

A sleeve 4 is removably secured within the wellbore liner 3 by means of a pair of expandable packers 5 .

The sleeve 4 comprises an annular space 6 formed between an inner wall 7 and an outer wall 8 of the sleeve 4, at which both the inner wall and the outer wall of the sleeve 4 comprise holes, viewed from the right side of the drawing 9.

A gel-filled capsule 11 is arranged in this annular space 6 . The capsule 11 comprises two parts 11A and 11B separated by a barrier 12 . The baffle 12 is permeable to water but not to the electromagnetic field sensitive gel 13 in the capsule 11 .

The sleeve 4 is equipped with a rechargeable accumulator 14 and a power receiver and/or transmitter device 15 adapted to apply an electromagnetic field to the first part 11A and the second part 11B of the capsule, respectively.

In FIG. 1A , an electromagnetic field is applied to the first part 11A and water is extruded from the gel 13 through the baffle 12 into the second part 11B where the gel 13 absorbs the water. As a result, the balloon 11 is pushed to the right in the figure closing the aperture 9 , thus preventing fluid from flowing into the interior of the sleeve 4 . The pressure equalization line 17 allows free movement of the first part 11A and the second part 11B of the capsule through the annular space 6 .

In Fig. 1B, an electromagnetic field is applied to the second part 11B, then water is extruded from the gel 13 of the second part 11B into the first part 11A, thus the capsule 11 moves to the left allowing the wellbore fluid to flow from the formation. 2 flows into wellbore 1 through holes 9 and 10.

Figure 2 shows a device substantially similar to that of Figure 1, wherein like reference numerals indicate like parts, except that two water permeable baffles 12A and 12B are provided in the capsule: There is a free body of water 16 in between to enable easy movement of water between the two parts 11A and 11B.

Figure 2A shows the device in the open position and Figure 2B shows the device in the closed position.

Referring to FIGS. 3A and 3B , another embodiment of a downhole fluid flow control device according to the present invention, which is installed in an opening of an oil well tubular, is shown, as shown in FIG. 6 .

Figure 3A shows the device 30 in an open position, thus allowing fluid to flow into the wellbore as indicated by arrows 31 .

The device 30 comprises a disc-shaped housing 32 including a disc-shaped cavity 33 therein.

An annular capsule 34 is mounted within the housing 32 such that a central opening in the capsule 34 is aligned with a central fluid flow channel 36 within the housing 32 . A sand screen 37 is provided at the inlet of the fluid flow passage 36 to prevent sand and other solid particles from flowing into the borehole.

The capsule 34 is surrounded by a torus 38 of foam, the pores of which are filled with water. The foam 38 also contains small cells or particles that are filled with an expanding gas. The capsule 34 is filled with an electromagnetic field sensitive gel 39 and has a cylindrical outer wall 40 which is permeable to water but not to the passage of the gel 39 .

An electronic coil 41 is incorporated into the body of the foam 38 . The coil 41 forms part of an electronic circuit 42 comprising an electronic switch 43 and a power source 44 in the form of a locally rechargeable battery. The battery may be powered by low voltage current passing through the well tubing wall and/or by a downhole generator (not shown) driven by a small fan or turbine itself powered by a Fluid flow through the wellbore is swirled.

In FIG. 3A , the switch 43 is open, so that no current flows through the coil 41 . As a result no electromagnetic field is applied to the gel 39 and the gel will release water which flows through the water permeable outer wall 40 of the capsule 34 and is absorbed by the foam 38 . This causes the gel 39 to contract causing the capsule 34 to contract towards the cylindrical outer wall 40 of the capsule, thereby forming a central opening 35 through which fluid can flow into the wellbore, as indicated by arrow 31 in the figure.

In FIG. 3B , the switch 43 is closed so that the electronic coil 41 induces an electromagnetic field to the gel 39 . As a result, the gel 39 will absorb water from the foam 38 through the cylindrical outer wall 40 of the capsule 34 . This causes the gel 39 to swell and the balloon 34 to expand thereby closing the central fluid flow channel 36 .

Switch 43 may be connected to a downhole sensor (not shown) which will close the switch if an inflow of water is detected. The sensors also form part of a sensor arrangement which monitors a range of parameters and is connected to a data processing unit which can be programmed to optimize production operations for the recovery of hydrocarbon liquids from the reservoir.

4A and 4B show an embodiment of the device according to the invention, in which the housing 50 has an oblong or oval shape. In this case, a gel-filled capsule 51 is separated from a pair of aqueous foam 52 by a pair of water-permeable baffles 53, as shown in FIG. 4A. The central liquid flow channel can be cylindrical or oval and includes a sand screen 54 . An electronic coil (not shown) is mounted within the housing 50 .

Figure 5 is a cross-sectional view of the device of Figures 4A, 4B encased in the wall of an oil well tubular 55. FIG. 6 is a three-dimensional perspective view of the oil well tubular 55 in FIG. 5, in which a pair of inflow control devices as shown in FIGS. 4A, 4B and 5 are embedded.

The housing 50 of the device shown in FIG. 6 is longitudinally oriented relative to the oil well tubular, thereby allowing the housing 50 to have a substantially flat shape, simplifying the manufacturing process of the housing 50 .

It should be understood that the gel-filled capsule may have a water-permeable wall that contacts the wellbore fluid and allows the gel to absorb water from the wellbore fluid and release water into the wellbore fluid. In this case the wall of the capsule should be permeable to water, but impermeable to the gel and the oil and/or gas produced.

It should be understood that the electromagnetic field-sensitive gel may be replaced by another excitation-sensitive gel, such as a temperature-sensitive gel, and that the capsule may be replaced by another deformable cavity, such as a cylindrical cavity, corresponding to the gel in the cavity. As the volume of the gel changes, the gel causes a piston to move up and down.

It should be understood that the electromagnetic field-sensitive gel may be replaced by another excitation-sensitive gel, such as a temperature-sensitive gel, and that the capsule may be replaced by another deformable cavity, such as a cylindrical cavity, corresponding to the gel in the cavity. As the volume of the gel changes, the gel causes a piston to move up and down.

Claims (10)

1. downhole hardware, be used to control the liquid flow that flows through a hydrocarbon liquid producing well, this device comprises a deformable cavity, and this deformable cavity comprises a responsive gel of excitation, and this encourages the volume of responsive gel to change along with the variation of selected electromagnetic field excitation parameter; This device also comprises a liquid flowing channel, and liquid flowing channel is closed corresponding to the increase of the volume of at least a portion gel and deformable cavity.

2. device according to claim 1, wherein gel is the responsive gel of an electromagnetic field, if the electromagnetic field of certain intensity is applied on this gel, this gel discharges water; And when non-electromagnetic field, this gel absorption water; Wherein, this device is equipped with an electromagnetic field emissions device, and this electromagnetic field emissions device is fit to apply the electromagnetic field of a selected intensity to gel.

3. device according to claim 2, wherein, gel is selected from the group that is made of polyacrylamide and polymethyl acid gel.

4. device according to claim 1, wherein, gel filling in a flexible packing, this packing corresponding at least a portion gel in the deformable cavity the increase of volume and the sealing liquid circulation road.

5. device according to claim 4, wherein, flexible packing is circular, and an osculum of the production liner in the inflow district of encirclement oil and/or gas production well; Wherein, the gel in the flexible packing can be excited and expand, thereby seals this osculum corresponding to detecting the water that flow in the well by this osculum.

6. device according to claim 4, wherein, flexible packing is circular, and is arranged in the annular space; Described annular space is between two coaxial production flow line parts, and production flow line is all being opened perforation near this annular space one end place, therefore, these perforates are sealed corresponding to the increase of at least a portion gel volume in the packing, and open corresponding to the minimizing of at least a portion gel volume in the packing.

7. device according to claim 5, wherein, flexible packing comprises two parts, these two parts are at least by a barrier partitions; This baffle plate is infiltrative to the gel right and wrong, but is that part is infiltrative to water at least.

8. device according to claim 7, wherein, described at least one baffle plate is made by a kind of material, and this material is infiltrative to water when an electromagnetic field is applied on the baffle plate, and this material is not infiltrative to the water right and wrong when having electromagnetic field to be applied on the baffle plate.

9. device according to claim 8, wherein, two parts of the flexible packing of described at least one barrier partitions, each parts includes according to claim 2 or 3 described gels; This device comprises one or more electromagnetism field source, and this electromagnetism field source is suitable for applying electromagnetic field selectively on parts of deformable cavity and/or baffle plate.

10. device according to claim 7, wherein, flexible packing comprises two filling gel packing parts, and these two parts are by a pair of gel impermeability barrier partitions, and this is separated by an interlude that contains water in a described chamber gel impermeability baffle plate.

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