Information
-
Patent Grant
-
6823936
-
Patent Number
6,823,936
-
Date Filed
Wednesday, October 2, 200221 years ago
-
Date Issued
Tuesday, November 30, 200419 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Bracewell & Patterson, L.L.P.
-
CPC
-
US Classifications
Field of Search
US
- 166 50
- 166 313
- 166 320
- 166 386
-
International Classifications
-
Abstract
A first passageway (17) provides a first fluid flow path, in a well between a first zone (9) and a, common region (26). A second passageway (23), outside the first passageway (17), provides a second fluid flow path; between the second zone (10) and the common region (26). The first passageway (17) is provided with a first flow controller (25), for controlling the flow of fluid between the first zone (9) and the common region (26). The second passageway (23) is provided with a second flow controller (28), for controlling the flow of fluid between the second zone (10) and the common region (26).
Description
The present invention relates to fluid flow control apparatus.
The control of the extraction or ingestion of fluid from or to a well in a fluid (e.g. oil or gas) extraction system is effected by chokes which have variable orifices in the production tube wall, typically operated by hydraulic or electric actuators.
FIG. 1
shows a sectional view of a well with a choke fitted within a casing
1
of a borehole
2
and sealed with a packer
3
. The choke body
4
of the choke is larger in diameter than production tubing
5
in order to accommodate a mechanical drive for controlling variable orifices
6
of the choke and its control and monitoring electronics around the circumference of the tubing
5
. Thus, the standard sizes of the casings used in the fluid extraction industry determine the maximum diameters of choke bodies. In order to maximise the output extraction rate of the well, the maximum diameter of production tubing
5
is utilised.
FIG. 1
also illustrates an extraction area
7
with a sand screen
8
fitted, as is typical. Invariably, the external diameter of the sand screen
8
is also limited by the bore of the casing
1
, in order that it can be passed down it during installation.
Thus, as shown in
FIG. 2
, in the situation where there are two extraction zones
9
and
10
, each with a respective one of sand screens
11
and
12
, typically two chokes are fitted. Since the outer diameter of each of the choke bodies
13
and
14
does not allow it to pass through a sand screen, and/of the choke assembly is often too long to be accommodated by a sand screen, the two chokes are arranged in series as shown in
FIG. 2
, which shows the extracted fluid from zone
9
passing through the sand screen
11
to the variable orifices
15
of the lower choke having choke body
13
in a conventional manner, as shown by the arrows on the Figure. However, the extracted fluid from zone
10
, through the sand screen
12
, has to pass through the space between the choke body
13
of the lower choke and the well casing
1
, in order to pass through variable orifices
16
of the upper choke having choke body
14
. An alternative arrangement is to fit a choke of smaller diameter, and thus smaller production tubing bore, in the position of the upper choke. However, these typical arrangements create a number of problems:
1/ The flow of fluid between the choke body
14
and the casing
1
is seriously restricted by the relatively small gap between them.
2/ If the upper choke having choke body
14
, is replaced with a choke of smaller dimensions, then a major redesign of the choke is required and the production flow tubing for the extraction from zone
10
is reduced.
It should be noted that when ingestion of fluid, typically water, into the well is required typically for maintenance, the same problems occur.
According to the present invention, there is provided apparatus for use in controlling the flow of fluid between first and second zones and a common region, comprising:
a first passageway, for providing a first fluid flow path, between the first zone and the common region, in use of the apparatus; and
a second passageway, outside the first passageway, for providing a second fluid flow path, between the second zone and the common region, in use of the apparatus, the first passageway being provided with first flow control means, for controlling the flow of fluid between the first zone and the common region and the second passageway being provided with second flow control means, for controlling the flow of fluid between the second zone and the common region.
The first and second passageways are preferably substantially concentric with each other.
The first and second control means may each comprise at least one orifice between the respective passageway and the common region.
The first and second passageways may be provided by first and second tubular members.
There may be sealing means between the first and second passageways for isolating the first and second flow paths from each other.
The apparatus may include a third passageway (for example provided by a tubular member) in fluid communications with the common region, which third passageway is preferably substantially co-axial with the first and second passageways.
There may be sealing means between the third passageway and the first and second passageways.
The third passageway may be in communication with the common region via at least one (preferably non-variable) orifice and in this case the or each such orifice may be in a wall of such tubular member providing the third passageway.
Each of the first and second passageways may be provided with means for varying the rate of fluid flow through the respective flow control means.
Apparatus according to the invention may be in the form of a choke assembly for use in controlling the flow of fluid between first and second zones and production tubing in a production well.
The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
FIGS. 1 and 2
are sectional views of known installations;
FIG. 3
is a schematic sectional view of apparatus according to an example of the invention;
FIG. 4
is an enlarged view of part of what is shown in
FIG. 3
; and
FIG. 5
is a part-sectional view showing how chokes of the apparatus are controlled.
FIG. 3
shows a sectional view of an installation using an example of the invention in a hydrocarbon production well. A tube
17
, providing a first passageway, passes concentrically through a lower choke having a choke body
18
and fixed (non-variable) orifices
19
are in the wall of output production tubing
20
of an upper choke having a choke body
21
. A removable plug
22
fitted as shown in
FIG. 3
is in the tube
17
between the fixed orifices
19
and variable orifices
25
of the upper choke, this plug being of a removable type, typically expandable, in order to facilitate the use of a wire line tool for maintenance.
The concentric tube
17
passes through production tubing
23
(providing a second passageway) of the lower choke having choke body
18
. The output from zone
9
passes via sand screen
11
through inner concentric tube
17
(as shown by the flow arrows), which is sealed from zone
10
by a seal
24
and out through the variable orifices
25
of the upper choke, into the space
26
between tubing
23
and tubing
20
and the well casing
1
. The flow then enters the output production tubing
20
via the fixed orifices
19
. Thus the orifices
25
, which are varied (see
FIG. 5
) by the actuator of the upper choke, control the fluid flow from zone
9
into the production tubing
20
.
The production zone
9
is isolated from the production zone
10
by a packer
27
, and the output from zone
10
passes via sand screen
12
through production tubing
23
(as shown by the flow arrows) outside the tube
17
, and out through variable orifices
28
of the lower choke, the orifices
28
being varied (see
FIG. 5
) by the actuator of the lower choke. The output from zone
10
then joins the fluid flow from zone
9
, in the space
26
(providing a common region) between the tubing
23
and the tubing
20
and the well casing
1
and into the production tubing
20
via the fixed orifices
19
.
Packers
29
and
30
prevent any leakage flow past the overall choke assembly.
The fluid flow from the variable orifices and into the fixed orifices is shown diagrammatically in
FIG. 4
, which is an enlarged view of part of the overall choke assembly.
FIG. 5
shows in more detail the realisation of what is shown in
FIGS. 3 and 4
. The seal
22
is in a tubular part
31
which is movable up and down in tubing
20
(which is fixed), tubular part
31
having, on the one hand, fixed orifices
32
receiving the flow from fixed orifices
19
and, on the other hand, having orifices
33
which vary the orifices
25
, the tubular part
31
being moved by the actuator of the upper choke. In the lower choke there is a tubular body
34
moved up and down by the actuator of the lower choke and having orifices
35
which vary the orifices
28
, tubing
23
being fixed.
It will be appreciated that the above example of the invention may also be used in reverse, that is for ingesting water, for example, into the zones
9
and
10
.
Claims
- 1. Apparatus for use in controlling the flow of fluid between first and second zones and a common region, comprising:a first passageway, for providing a first fluid flow path, between the first zone and the common region, in use of the apparatus; a second passageway, outside the first passageway, for providing a second fluid flow path, between the second zone and the common region, in use of the apparatus, the first passageway being provided with first flow control means, for controlling the flow of fluid between the first zone and the common region and the second passageway being provided with second flow control means, for controlling the flow of fluid between the second zone and the common region; and a third passageway in fluid communication with the common region via at least one orifice.
- 2. Apparatus according to claim 1, wherein the first and second passageway are substantially concentric with each other.
- 3. Apparatus according to claim 1, wherein the first and second control means each comprises at least one orifice between the respective passageway and the common region.
- 4. Apparatus according to claim 1, wherein the first and second passageways are provided by first and second tubular members.
- 5. Apparatus according to claim 1, wherein there is sealing means between the first and second passageways for isolating the first and second flow paths from each other.
- 6. Apparatus according to claim 1, wherein the third passageway is substantially co-axial with the first and second passageways.
- 7. Apparatus according to claim 1, wherein there is sealing means between the third passageway and the first and second passageways.
- 8. Apparatus according to claim 1, wherein said at least one orifice via which the third passageway is in communication with the common region is non-variable.
- 9. Apparatus according to claim 1, wherein the third passageway is provided by a tubular member.
- 10. Apparatus according to claim 9, wherein said at least one orifice via which the third passageway is in communication with the common region is in a wall of the tubular member providing the third passageway.
- 11. Apparatus according to claim 1, wherein each of the first and second passageways is provided with means for varying the rate of fluid flow through the respective flow control means.
- 12. Apparatus according to claim 1, in the form of a choke assembly for use in controlling the flow of fluid between first and second zones and production tubing in a production well.
Priority Claims (1)
Number |
Date |
Country |
Kind |
0104269 |
Feb 2001 |
GB |
|
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/GB02/00691 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO02/06678 |
8/29/2002 |
WO |
A |
US Referenced Citations (13)
Foreign Referenced Citations (6)
Number |
Date |
Country |
851096 |
Oct 1960 |
GB |
1008383 |
Oct 1965 |
GB |
1105949 |
Mar 1968 |
GB |
WO 9208875 |
May 1992 |
WO |
WO 9931352 |
Jun 1999 |
WO |
WO 0029715 |
May 2000 |
WO |