U.S. patent application number 11/630579 was filed with the patent office on 2008-02-07 for valve.
Invention is credited to Giancarlo Pietro Tomasso Pia.
Application Number | 20080029273 11/630579 |
Document ID | / |
Family ID | 32800082 |
Filed Date | 2008-02-07 |
United States Patent
Application |
20080029273 |
Kind Code |
A1 |
Pia; Giancarlo Pietro
Tomasso |
February 7, 2008 |
Valve
Abstract
A downhole valve comprises a body defining a through bore and a
valve member for location in the body and movable between an open
position and a closed position. The valve has a first configuration
in which the valve member is normally closed, and will hold a
pressure differential in a first direction, and a second
configuration in which the valve member is closed and will maintain
a pressure differential in the first direction, and also in an
opposite second direction and a third configuration in which the
valve member is locked in the open position until it is
deliberately closed.
Inventors: |
Pia; Giancarlo Pietro Tomasso;
(Aberdeen, GB) |
Correspondence
Address: |
LAW OFFICES OF CHRISTOPHER L. MAKAY
1634 MILAM BUILDING
115 EAST TRAVIS STREET
SAN ANTONIO
TX
78205-1763
US
|
Family ID: |
32800082 |
Appl. No.: |
11/630579 |
Filed: |
June 24, 2005 |
PCT Filed: |
June 24, 2005 |
PCT NO: |
PCT/GB05/02506 |
371 Date: |
December 22, 2006 |
Current U.S.
Class: |
166/373 |
Current CPC
Class: |
E21B 34/102 20130101;
E21B 2200/05 20200501 |
Class at
Publication: |
166/373 |
International
Class: |
E21B 34/06 20060101
E21B034/06 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 24, 2004 |
GB |
0414128.9 |
Claims
1. A downhole valve comprising: a body defining a through bore; and
a valve member for location in the body and movable between an open
position and a closed position, the valve having a first
configuration in which the valve member is normally closed, and
will hold a pressure differential in a first direction, and a
second configuration in which the valve member is closed and will
maintain a pressure differential in said first direction and also
in an opposite second direction.
2-112. (canceled)
Description
FIELD OF THE INVENTION
[0001] This invention relates to valves, and in particular but not
exclusively to valves for use in downhole applications.
BACKGROUND OF THE INVENTION
[0002] In the oil and gas exploration and production industry,
subsurface hydrocarbon-bearing formations are accessed from surface
by drilling bores, which bores are subsequently lined with metal
tubing known as casing or liner. In instances where the formation
pressure exceeds the hydrostatic pressure produced by the column of
fluid in the well bore, one or more valves must be provided in the
well bore to prevent uncontrolled escape of hydrocarbons from the
well. In contrast, in other instances, it may be desirable to
protect the formation from hydrostatic pressure to prevent fluid
flowing into, and damaging, the formation, and in such cases the
column of fluid in the well bore must be isolated from the
formation.
[0003] A wide range of valves have been proposed and used in well
bores to cope with the situations outlined above and to provide
for, for example, the safe deployment of tools and devices into the
well bore.
SUMMARY OF THE INVENTION
[0004] According to a first aspect of the present invention there
is provided a valve comprising:
[0005] a body defining a through bore; and
[0006] a valve member for location in the body and movable between
an open position and a closed position, the valve having a first
configuration in which the valve member is normally closed, and
will hold a pressure differential in a first direction, and a
second configuration in which the valve member is closed and will
maintain a pressure differential in said first direction and also
in an opposite second direction.
[0007] The two different configurations of the valve extend the
range of functionalities of the valve. For example, for use in
managed pressure or under-balanced drilling applications, the valve
may be utilised as a downhole deployment valve to isolate the
formation from the well bore, that is the valve will hold a
differential pressure from below. However, if the valve is
reconfigured to the second configuration, a fluid barrier may be
provided above the valve to operate in addition to the mechanical
barrier provided by the valve member.
[0008] In accordance with a second aspect of the present invention
there is provided a valve comprising:
[0009] a valve body; and
[0010] a valve member mounted in the body, the valve member being
movable between an open position and a closed position; the valve
being operable in a fail as is mode and a fail-safe closed
mode.
[0011] Alternatively, or in addition, the valve could also be
configured to be operable in a fail as is mode and a fail-safe open
mode.
[0012] This aspect of the invention offers numerous advantages in
that the fail-safe operation of the valve can be arranged to suit
current operations. For example, in normal operation it may be
desired to have the valve operate in fail-safe shut mode, such that
the valve operates as a safety valve. However, when an item, such
as a drill string, extends through the valve, it may be
advantageous to have the valve locked open or fail open in order
not to trap the string in the valve.
[0013] The above-noted aspects of the present invention may both be
provided in the same valve, or may be provided independently.
[0014] Preferably, the valve is adapted to hold a differential
pressure from below while in the first configuration, although in
other embodiments the valve may be adapted to hold differential
pressure from above. Preferably, the valve member is biased towards
the closed position, for example by means of a suitable spring.
[0015] The valve member may take any appropriate form, including a
ball valve. However, it is preferred that the valve member is a
flapper valve, and most particularly a contoured or curved
flapper.
[0016] Preferably, the valve includes an opening member, which will
typically be in the form of a sleeve. The opening member may be
biased towards a position which allows the valve member to close or
remain in the closed position. The opening member may be movable to
move the valve member from the closed position towards the open
position. The opening member may incorporate a valve seat, or a
valve seat may be provided independently of the member.
[0017] The opening member may be actuated by any appropriate means,
but is preferably gas or fluid actuated. Thus, the opening member
may be actuated by pressurised gas or liquid supplied from a remote
gas or fluid source. In the preferred application of the valve,
that is in a downhole environment, the actuating pressure will most
likely be supplied from surface. The pressure may be supplied via
appropriate control lines, or may be applied via an annulus,
typically a secondary annulus provided between two casing strings,
or via a drill pipe string or via an electro-hydraulic control
system. The opening member may be subject to one or more selected
actuation sequences, with actuating pressure being supplied by one
or more gas or fluid conduits, which gas or fluid conduits could be
control lines, an annulus, a drill pipe string or an
electro-hydraulic control system. While the opening member itself
may be hydraulically actuated, pressure may be applied or
transmitted to the opening member actuating arrangement from
surface via gas or liquid.
[0018] The opening member may incorporate a piston, and hydraulic
fluid pressure acting on the piston will tend to move the piston to
open the valve member. Preferably, means are provided for returning
the opening member to a first or retracted position, in which the
valve member may remain closed. The return means may utilise
hydraulic fluid pressure, but most preferably comprises a spring,
such that, for example, only a single hydraulic line or supply is
required to provide or control movement of the opening member in
both directions. The spring may comprise a mechanical spring or a
pressure spring.
[0019] Preferably, the valve comprises a support member, which may
be selectively positioned to maintain the valve member in the
closed position. The support member may take any appropriate form,
but is preferably in the form of a sleeve. In a first or retracted
position the support member may permit movement of the valve member
between the open and closed positions, however in a second or
extended position the support member may prevent or restrict
movement of the valve member from the closed position.
[0020] The support member may be moved towards the extended
position by any appropriate means, but is preferably gas or fluid
actuated. Gas or fluid actuation may be utilised to move the
support member from the extended position to the retracted
position, or a return spring or the like may be provided, however
it is desired that an external mechanical force must be applied to
the support member in order to retract the member.
[0021] Preferably, the valve includes a retaining member, which may
be configured to retain the valve member in the open position. The
retaining member may take the form of a sleeve, and may be movable
between a retracted position in which the valve member is free to
close, and an extended position in which the valve member is
restrained in the open position, typically in a volume between the
valve body and the retaining member.
[0022] In a preferred embodiment, a single member serves as both
the support member and the retaining member, that is a support and
retaining member may be selectively positioned to maintain the
valve member in the closed position or in the open position, though
in other embodiments it may be that two separate members are
provided.
[0023] Both the opening member and support and/or retaining
member(s) may be actuated by any appropriate means but are
preferably fluid or gas actuated. Thus, the opening and support
and/or retaining members may be actuated by pressurised gas or
fluid supplied from a remote source, on surface or within the well.
The pressure may be supplied via appropriate control lines or may
be applied via an annulus, drillstring or any downhole control
system. Both the opening and support and/or retaining members may
be subject to one or more actuation sequences, with actuating
pressure being supplied by one or more gas or fluid conduits, which
gas or fluid conduits could be control lines, an annulus, drill
pipe or an electro-hydraulic control system.
[0024] Actuation of the opening member and support and/or retaining
members can be done independently of, in association with, or in
sequence with the other member or members using pre-determined
pressure levels or sequences or rising pressure levels to trigger
the actuation sequence.
[0025] Timing of the actuation of the opening member and support
and/or retaining members within the valve can be sequenced or
controlled using restrictors to restrict the pressure or fluid flow
rate within the valve to control the timing and sequence of the
members in relation to each other.
[0026] One or both of the support member and retaining member may
cooperate with an opening member, and in one embodiment ends of a
combined support and retaining member and an opening member may
selectively engage or otherwise cooperate such that movement of one
member induces movement of the other member, thus simplifying
operation and control of the valve. Furthermore, if the actuating
arrangement for one member should fail or be rendered inoperative,
it may be possible to actuate the failed member via the other
member. Also, where the two members track one another with little
or no clearance therebetween, this serves to eliminate or reduce
ingress of debris and cuttings behind the members and into the
volume occupied by the valve member, which debris might otherwise
interfere with the operation of the valve.
[0027] One or both of the support member and the retaining member
may be actuated in a similar manner to the opening member, as
described above.
[0028] The valve may be provided in combination with a catcher for
location above the valve, which catcher may operate in conjunction
with a dense fluid barrier above the valve. Preferably, the catcher
includes one or more members for extending into the bore to arrest
the fall of an item that might otherwise damage the valve. The
members may be normally extended, or normally retracted. The
members may be actuated in any appropriate manner, including by
means of pressure, by gas or fluid control lines, or mechanically.
The catcher may be integral with the valve, or may be provided
separately. The catcher may be actuated independently or in
combination with the valve, for example the catcher members may be
extended independently of the valve configuration or may be
extended and retracted as the valve is closed and opened.
[0029] Further aspects of the present invention relate to methods
of reconfiguring valves of the first and second aspects between
their respective configurations.
[0030] In still further aspects of the present invention two or
more valves may be provided in a well bore. The valves may be made
in accordance with the above described embodiments, but may take
other forms, and one valve may take the form of a surface sealing
device, such as a device to restrict or prevent flow around the
BOPs, or a rotating control diverter as provided in an under
balanced drilling (UBD) well. The valves may be located in close
proximity to one another, or more preferably may be spaced apart,
for example one deep set and one close to surface. Typically, the
valves will be spaced apart sufficiently such that the space
between the valves may accommodate and isolate a tool or device
and, as described below, function in a somewhat similar manner to a
surface lubricator. The valves may be spaced apart by a distance of
1000 feet or more, or a distance suitable to permit the volume
between the valves to accommodate, for example, screens, inflatable
screens, sand screens, logging tools, drilling assemblies,
completions, well intervention tool strings and well work-over type
strings, or indeed anything likely to be deployed into or retrieved
from a live well. The valves may be operated simultaneously, but
are most preferably independently operable.
[0031] The provision of two or more valves, not necessarily in
accordance with the first and second aspects of the invention,
offers numerous advantages. For example, closing a lower or deep
set valve while opening an upper or shallow set valve allows a tool
string, sandscreens, expandable tubulars or the like to be run into
a live well and positioned between the valves, and the upper valve
then closed. Conventional drill pipe or the like may then be run
into the bore through conventional BOPs and the like, the upper
valve opened, and the drill pipe string then stabbed into or
otherwise connected to the tool string located between the valves.
The lower valve may then be opened and the tool string advanced
into the section of bore which intersects the formation.
[0032] The weight of the tool string may be selected such that, on
opening the deep set valve, the weight of the string will provide a
downward force substantially equal to or greater than any pressure
force acting to push the string upwards and out of the bore. In
certain embodiments such an object may itself act as a pressure
barrier, and it may thus be possible to omit the upper valve.
[0033] This arrangement of valves or other pressure-containing
devices is particularly useful in managed pressure drilling, that
is in UBD wells or in wells drilled near or at balance. Indeed, all
of the various different aspects of the invention disclosed herein
are particularly well suited for use in managed pressure drilling
applications.
[0034] Another aspect of the invention relates to a valve provided
in combination with a sensor to measure or monitor the fluid level
in the well above the valve, to ensure that the valve is not
leaking. Such measurement may be, for instance, carried out using
an echo meter.
[0035] Another aspect of the invention relates to the use of the
valve as a measuring device of pressure below, above or at the
valve depth, and the use of the valve as a MWD data receiver,
transmitter or repeater.
[0036] Another aspect of the invention relates to the use of
command or control data transmitted from a drill string, completion
string or other tubular conduit deployed into the borehole to
trigger a valve or remote electro-hydraulic control system to
actuate the valve. In one embodiment of this aspect of the
invention, ultrasonic waves or electromagnetic waves may be
utilised to trigger the valve actuation sequencing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] These and other aspects of the present invention will now be
described, by way of example, with reference to the accompanying
drawings, in which:
[0038] FIG. 1 shows a valve in accordance with the preferred
embodiment of the present invention in a normally closed
configuration, and configured to hold pressure from below;
[0039] FIG. 2 is a sectional view of the valve of FIG. 1, showing
the valve open;
[0040] FIG. 3 is a sectional view of the valve of FIG. 1, showing
the valve locked open; and
[0041] FIG. 4 is a sectional view of the valve of FIG. 1, showing
the valve locked closed.
DETAILED DESCRIPTION OF THE DRAWINGS
[0042] The Figures illustrate a full bore isolation valve 10 in
accordance with a preferred embodiment of the present invention.
The valve 10 is intended to be incorporated in a string of tubulars
to be located in a well bore, typically in a concentric casing
string, that is a string of casing which is run inside casing or
liner previously located in the well bore. The valve 10 has a
generally cylindrical body 12 with top and bottom subs 14, 16
adapted for connection to adjacent sections of the casing string.
The valve body 12 further comprises a spring housing 18 which is
coupled to the top sub 14, and a flapper housing 20 which extends
between the spring housing 18 and the bottom sub 16.
[0043] Mounted within the valve body 12 is a valve member in the
form of a curved flapper 22. The flapper 22 is mounted to the
housing 20 via a pivot pin 24 and a spring 26, the spring tending
to move the flapper 22 to the closed position, as illustrated in
FIG. 1. In other embodiments the flapper 22 could be mounted on a
separate collar or the like within the body.
[0044] In the closed position the flapper 22 engages a valve seat
28 formed on the lower end of an opening sleeve 30 which is axially
movably mounted within the body 12. The sleeve 30 is biased upwards
towards the valve closed position, as illustrated in FIG. 1, by a
compression spring 32. The upper end of the spring 32 engages a
shoulder forming part of an annular piston 34 on the exterior of
the sleeve 30. A fluid supply line 36 communicates with an upper
face of the piston 34, such that supply of pressurised fluid via
the line 36 will tend to move the sleeve 30 downwardly, and thus
push the flapper 22 towards the open position, as illustrated in
FIG. 2 of the drawings.
[0045] The lower part of the valve body 12 accommodates a support
and retaining sleeve 38. In FIG. 1, the sleeve 38 is shown in the
fully retracted position, in which the sleeve does not impact on
the ability of the flapper 22 to open and close. Like the opening
sleeve 30, the support and retaining sleeve 38 includes an annular
piston 40 and a further hydraulic supply line allows the supply of
hydraulic fluid to the lower side of the piston 40. Thus, by
supplying fluid to the volume below the piston 40, it is possible
to extend the sleeve towards the flapper 22.
[0046] FIGS. 1 and 2 of the drawings illustrate the valve 10 in a
fail-safe shut configuration. That is, if the supply of hydraulic
fluid to the valve 10 fails, the spring 32 will tend to return the
sleeve 30 to its retracted position, as in FIG. 1, and the flapper
spring 26 will tend to move the flapper 22 to the closed position.
As will be described below, it is possible to reconfigure the valve
10 to a fail-safe open configuration. In particular, if, once the
valve is open, as illustrated in FIG. 2, and the sleeve 30 has been
extended such that the valve seat contacts the upper end of the
support and retaining sleeve 38, hydraulic fluid is then supplied
to extend the sleeve 38, while simultaneously fluid is permitted to
bleed through the line 36, perhaps restricted in flow rate by a
restrictor, and thus permit retraction of the sleeve 30. The
support and retaining sleeve 38 will push the opening sleeve 30
upwards, and thus trap the flapper 22 behind the advancing sleeve
38. As long as pressure is maintained to extend the sleeve 38, the
valve will remain open, as the flapper 22 is trapped behind the
sleeve 38. However, even if the supply of hydraulic fluid tending
to extend the sleeve 38 should fail, there is no return spring or
other biasing force tending to retract the sleeve 38, such that the
sleeve 38 will remain in its extended position, and the valve will
remain open.
[0047] It will be noted that the ends of the sleeves 30,38 are in
contact with each other, or at least close to each other, in a
number of the valve configurations (FIGS. 2, 3 and 4). This offers
two significant advantages, one being that the contacting sleeves
may prevent ingress of debris, cuttings and other material into the
volume between the valve body and the sleeves, which includes the
space occupied by the open flapper 22. Furthermore, if the
actuating arrangement for one sleeve fails, for example a fluid
supply line is damaged or the spring 32 sticks, the other sleeve
may be utilised to move the failed sleeve.
[0048] Thus, it will be apparent to those of skill in the art that
the valve 10 may be configured as a fail-safe closed valve, when
utilised in the configuration illustrated in FIGS. 1 and 2, or as a
fail-safe open valve or fail as is when locked open, when used in
the configuration illustrated in FIG. 3.
[0049] Furthermore, in the configuration illustrated in FIG. 1, the
valve 10 is normally closed, and will hold a differential pressure
from below. However, a differential pressure from above will tend
to open the valve. This configuration is useful, for example, in an
under-balanced situation, where the formation pressure, in
communication with the lower end of the valve 10, is higher than
the well bore pressure above the valve. However, there may be
circumstances in which it is desired for the valve to have the
facility to hold differential pressure from above, for example, if
it is desired to fill the well bore with a relatively dense fluid
and thus provide a further safety barrier between the formation and
surface, which barrier may also serve to arrest the fall of items
through the well bore which might otherwise damage the valve. This
may be achieved by, starting from the valve configuration of FIG.
1, advancing the support and retaining sleeve 38 while the flapper
22 remains in the closed position. The sleeve 38 advances until the
upper end of the sleeve 38 engages and supports the lower surface
of the flapper 22. Thus, in the event of a differential pressure
being applied from above the valve, the flapper 22 will be
supported in the closed position by the extended sleeve 38.
[0050] Those of skill in the art will appreciate that the valve 10
described above offers many advantages over prior art valves. The
low profile of the valve 10 allows the valve 10 to be, for example,
passed through conventional casing of larger diameters, while
permitting passage of standard drill bit sizes and drill string
components through the valve.
[0051] Thus, the valve 10 has the ability to hold pressure from
below, or alternatively the ability to hold pressure both from
above and below. Of course in other embodiments the orientation of
the valve 10 may be reversed, such that the valve is configured to
hold pressure from above, or from above and below.
[0052] Those of skill in the art will recognise that the ability of
the valve 10 to be configured in a fail-safe open or fail-safe shut
configuration also offers significant advantages, and extends the
operational envelope of the valve.
[0053] In the configuration in which the valve will hold pressure
from both above and below, the valve 10 provides a mechanical
barrier that is independent of well pressure. Furthermore, this
allows a fluid barrier to be provided above the valve 10 in
addition to the mechanical barrier provided by the valve itself,
which allows provision of multiple barriers using only a single
tool, and independent of well\reservoir pressure from below to make
and hold the seal. The valve also has the ability to operate with a
relatively high differential pressure across the valve.
[0054] If desired, the valve may include pressure sensors,
communicating to surface, to permit monitoring of pressure above
and below the valve 10, or detectors that indicate flapper or
sleeve position. Alternatively, or in addition, the valve may
include sensors for detecting electromagnetic (EM) or other
signals, and means for relaying these signals towards surface by
other means, for example through cabling. For example, the sensors
may detect signals output by an EM MWD tool in the well bore below
the valve, and transmit these signals to surface. This may be
useful in applications where, for example, formations surrounding
the well bore above the producing formation contains salt or brine
and tend to attenuate EM signals.
[0055] The valve may be provided in combination with sensors to
measure or monitor the fluid level in the well above the valve, to
ensure that the valve is not leaking. Such measurement may be
carried out, for example, by an echo meter.
[0056] As noted above, the valve 10 may be used singly, or two or
more valves may be provided in a bore, or in the same string. The
valves may operate completely independently with separate hydraulic
lines passing from the valves to surface, or the valves may operate
together, being linked by common hydraulic lines. Alternatively,
the valves may be supplied using common hydraulic lines, but
appropriate valving in the lines may be utilised such that, for
example, a selected valve is only actuated when the pressure in the
hydraulic lines rises above a predetermined level.
[0057] In other embodiments, one or both valves may be actuated in
part via annulus pressure, or by pressure applied via a tubular
support string, such as a string of drill pipe, or by a combination
of both, as an alternative to or in addition to control line
actuation. The ability to use different conduits to apply pressure
to the valve or valves provides increased flexibility, and
facilitates provision of different valve operating sequences.
[0058] One example of a use for running two valves in the same well
is to allow running of sand control screens, which may be either
solid or expandable. Currently, sand control screens cannot be run
in accordance with conventional barrier policy in under-balanced
wells, as even with a single deployment valve deep set and rotating
blow-out preventors (RBOPs) or the snubbing unit as part of the
surface BOP barrier environment, sand screens with holes in the
tubes provide a possible leak path to the outside of the well at
surface while the sand screen is located in the RBOP or snubbing
unit. This problem can be overcome by running two valves, one deep
set which may be used for all drilling activities as normal, and a
second valve near to surface, to isolate the well near surface. In
accordance with an embodiment of one aspect of the present
invention, two valves as described above may be provided and a
section of sand screen may be run into the well as follows.
[0059] Firstly, the surface RBOPs or BOPs are closed to isolate the
well. The deep set valve is then closed to provide a mechanical
barrier, isolating the hydrocarbon-producing formation from the
upper part of the well bore. If the valve is locked closed, such
that it may withstand differential pressure from above, a
relatively dense fluid may then be circulated into the well bore
above the deep set valve, to act as a second barrier.
[0060] The well pressure from the section of the well bore isolated
above the deep set valve is then bled down, and checks made to
ensure that there is no leak path past the deep set valve. The
surface BOPs may then be opened and the sand screens deployed into
the well, and hung off a profile just below the shallow set valves.
The sand screen running string is then withdrawn and the shallow
set valve and the surface BOPs are closed. Drill pipe is then run
into the surface BOPs in conventional fashion for under-balanced
tripping operations. The shallow set valve is opened and may be
locked and the drill pipe run through the valve and the end of the
drill pipe stabbed into the sand screens, which releases the
hang-off of the sand screen. At this point, the surface BOPs form a
seal with the drill pipe string. Next, pressure is allowed to
equalise across the deep set valve, the valve is then opened and
may be locked, and the sand screen then run through the open deep
set valve.
[0061] It will be apparent to those of skill in the art that the
above-described embodiments are merely exemplary of the present
invention, and that various modifications and improvements may be
made thereto, without departing from the scope of the invention.
For example, in the aspects of the invention described above which
utilise two spaced-apart valves, in other embodiments the upper
valve could be replaced by an alternative barrier, such as an
alternative valve form, an inflatable packer, or a mechanical set
bridge plug type packer. Furthermore, a surface sealing device at
the BOP or rotating control diverter may serve as the upper
valve.
* * * * *