U.S. patent application number 11/672194 was filed with the patent office on 2008-08-07 for subsea intervention with compliant guide.
This patent application is currently assigned to Schlumberger Technology Corporation. Invention is credited to Axel Destremau, Alan Johnston, Yves Le Moign, Lars Mangal, Pascal Paneta, Andrea Sbordone, Rene Schuurman, Eric Smedstad.
Application Number | 20080185153 11/672194 |
Document ID | / |
Family ID | 39186602 |
Filed Date | 2008-08-07 |
United States Patent
Application |
20080185153 |
Kind Code |
A1 |
Smedstad; Eric ; et
al. |
August 7, 2008 |
SUBSEA INTERVENTION WITH COMPLIANT GUIDE
Abstract
A technique improves the capabilities and performance of subsea
intervention operations. An intervention vessel is coupled with a
subsea well system via a compliant guide. The structure and
arrangement of the compliant guide enables passage of a variety of
intervention tools and a variety of conveyance mechanisms to
facilitate performance of intervention operations.
Inventors: |
Smedstad; Eric; (League
City, TX) ; Le Moign; Yves; (Singapore, SG) ;
Sbordone; Andrea; (Venice, IT) ; Schuurman; Rene;
(Singapore, SG) ; Paneta; Pascal; (Longiumeau,
FR) ; Destremau; Axel; (Houston, TX) ;
Johnston; Alan; (Noisy-Le-Roi, FR) ; Mangal;
Lars; (Croissy Sur Seine, FR) |
Correspondence
Address: |
SCHLUMBERGER TECHNOLOGY CORPORATION
300 SCHLUMBERGER DRIVE
ROSHARON
TX
77478
US
|
Assignee: |
Schlumberger Technology
Corporation
Sugar Land
TX
|
Family ID: |
39186602 |
Appl. No.: |
11/672194 |
Filed: |
February 7, 2007 |
Current U.S.
Class: |
166/345 |
Current CPC
Class: |
E21B 17/015 20130101;
E21B 17/01 20130101 |
Class at
Publication: |
166/345 |
International
Class: |
E21B 43/01 20060101
E21B043/01 |
Claims
1. A method for subsea intervention, comprising: coupling an
intervention vessel and a subsea well system with a compliant
guide; conveying intervention tools through the compliant guide
with a cable-type conveyance; and utilizing the intervention tools
to perform an intervention operation.
2. The method as recited in claim 1, wherein utilizing comprises
utilizing the intervention tools to perform an intervention
operation in a subsea well.
3. The method as recited in claim 1, wherein utilizing comprises
utilizing the intervention tools to perform an intervention
operation in a subsea flowline.
4. The method as recited in claim 1, further comprising deploying a
fluid into an interior of the compliant guide; and maintaining the
fluid separate from well fluids.
5. The method as recited in claim 4, further comprising applying
pressure to the fluid.
6. The method as recited in claim 1, further comprising changing
the cable-type conveyance to another type of conveyance for
movement through the compliant guide.
7. The method as recited in claim 6, wherein changing comprises
changing the cable-type conveyance to a coiled tubing
conveyance.
8. The method as recited in claim 6, wherein changing comprises
changing the cable-type conveyance to a coiled rod conveyance.
9. The method as recited in claim 1, further comprising arranging
the complaint guide in a generally S-shaped pattern.
10. The method as recited in claim 1, further comprising
temporarily moving the intervention vessel to change the
configuration of the compliant guide for facilitating passage of
intervention tools.
11. The method as recited in claim 1, further comprising performing
grease injection operations on the surface.
12. A method for subsea intervention, comprising: coupling an
intervention vessel and a subsea well system with a spoolable
compliant guide extending untethered between the intervention
vessel and the subsea well system; isolating an interior of the
spoolable compliant guide from well fluids; and arranging the
spoolable compliant guide to accommodate passage of a plurality of
conveyance types.
13. The method as recited in claim 12, wherein arranging comprises
accommodating passage of cable-type conveyances, coiled tubing, or
coiled rod.
14. The method as recited in claim 12, further comprising filling
the spoolable compliant guide with a fluid separated from well
fluids.
15. The method as recited in claim 12, further comprising enabling
swiveling of the spoolable compliant guide.
16. The method as recited in claim 12, further comprising
temporarily moving the intervention vessel to change the
configuration of the compliant guide for facilitating passage of an
intervention tool
17. The method as recited in claim 12, further comprising
connecting a lower end of the spoolable compliant guide to a subsea
lubricator.
18. A system, comprising: a deep water subsea well system; a
compliant guide coupled to the deep water subsea well system, the
compliant guide being arranged to accommodate passage of a variety
of intervention tools and conveyance systems; and a seal positioned
to limit incursion of well fluid into the compliant guide.
19. The system as recited in claim 18, wherein the deep water
subsea well system comprises a subsea lubricator and a blowout
preventor.
20. The system as recited in claim 18, wherein the deep water
subsea well system comprises a disconnect device to enable an
emergency disconnect.
21. The system as recited in claim 18, further comprising a swivel
connection positioned to enable swiveling of the compliant
guide.
22. The system as recited in claim 18, further comprising a
buoyancy device positioned to facilitate placement of the compliant
guide into a desired configuration.
23. The system as recited in claim 18, further comprising a bend
restrictor coupled to the compliant guide.
24. The system as recited in claim 18, wherein the compliant guide
is coupled to an intervention vessel located at the surface.
25. The system as recited in claim 18, further comprising a
conveyance system and an intervention tool coupled to the
conveyance system for movement through the compliant guide.
26. The system as recited in claim 24, further comprising a return
hose coupled between the intervention vessel and the deep water
subsea well system.
27. A method for subsea intervention, comprising: locating a subsea
well system in deep water; coupling a compliant guide between an
intervention vessel and the subsea well system; and passing an
intervention tool through the compliant guide via a conveyance
system of the type unable to transmit a pushing force.
28. The method as recited in claim 27, wherein locating the subsea
well system comprises engaging the subsea well system with a subsea
well.
29. The method as recited in claim 27, wherein locating the subsea
well system comprises engaging the subsea well system with a subsea
flowline.
Description
BACKGROUND
[0001] The retrieval of desired fluids, such as hydrocarbon based
fluids, is pursued in subsea environments. Production and transfer
of fluids from subsea wells relies on subsea installations, subsea
flow lines and other equipment. Additionally, preparation and
servicing of the subsea well relies on the ability to conduct
subsea intervention work.
[0002] Subsea intervention work involves numerous challenges not
normally faced when working on land wells or offshore platforms. In
most cases, intervention in subsea wells is performed from a
floating platform or ship by extending the borehole to a surface
location by a tensioned riser. However, the cost of platforms is
high and the availability of vessels capable of adequately
performing intervention work is limited.
[0003] A variety of existing techniques are currently used for
intervention work. In shallow waters, for example, subsea
intervention work can be performed with a specially equipped vessel
having subsea lubricators, subsea pressure control equipment, and
wave motion compensating systems. In most cases, guide wires
extending from a wellhead all the way to the vessel combined with
the aid of professional divers is required. Additionally, this
approach requires that equipment is conveyed and guided from the
vessel to the subsea installation through open waters. Once the
subsea lubricator is connected to the subsea installation and the
tools are inside, the conveyance cable remains exposed to open
waters. Because existing non-rig intervention capability is limited
to shallow water wireline and slick line operations, most
intervention on subsea wells is currently performed with expensive
and scarce heavy drilling units.
SUMMARY
[0004] In general, the present invention provides a technique for
subsea intervention operations. An intervention vessel is coupled
with a subsea well system via a compliant guide. The structure and
arrangement of the compliant guide enables passage of a variety of
intervention tools and a variety of conveyance mechanisms to
facilitate performance of intervention operations. The intervention
operations can be performed on, for example, a subsea well or a
subsea flowline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] Certain embodiments of the invention will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements, and:
[0006] FIG. 1 is a schematic front elevation view of a subsea
intervention system, according to an embodiment of the present
invention; and
[0007] FIG. 2 is a schematic front elevation view of another
configuration of the subsea intervention system, according to an
alternate embodiment of the present invention.
DETAILED DESCRIPTION
[0008] In the following description, numerous details are set forth
to provide an understanding of the present invention. However, it
will be understood by those of ordinary skill in the art that the
present invention may be practiced without these details and that
numerous variations or modifications from the described embodiments
may be possible.
[0009] The present invention generally relates to a technique for
intervening in subsea installations, such as subsea wells or subsea
flowlines. The technique enables intervention tools to be conveyed
via different methods of conveyance through a compliant guide, such
as a spoolable compliant guide, that is coupled between the subsea
installation and a vessel on the sea surface. The technique also
enables the use of a variety of conveyances in non-rig deep water
interventions.
[0010] Intervention tools are conveyed from the surface vessel and
through the compliant guide to an entry point of the subsea
installation which may be located on the seabed. For tools or
completion components having a larger outside diameter, a subsea
lubricator can be used for deployment. A dynamic seal is positioned
to prevent well fluids from entering the compliant guide, thus
reducing concerns related to incursion of hydrocarbons into the
compliant guide. The technique and utilization of the compliant
guide enables subsea intervention in a variety of different
scenarios, with a variety of different intervention tools, and with
a variety of interchangeable conveyance systems.
[0011] The compliant guide is arranged to accommodate flexible
conveyance systems of the type that are generally unsuitable for
transmitting a pushing force, e.g. a cable-type conveyance system.
This enables the use of cable-type conveyance systems, e.g.
wireline or slickline conveyance systems, in deep water
intervention operations. The compliant guide is flexible and can
undergo dynamic and temporary (or long-term) changes in shape to
facilitate tool string passage when the tool string is coupled to a
flexible conveyance system.
[0012] The ability to use different conveyances or to interchange
conveyances during a given operation greatly enhances the
adaptability of the present system to a variety of intervention
environments and operations. When starting an intervention job, the
execution of certain operations depends on the real state of the
subsea installation determined once access is gained to the
installation. During the planning stage of the intervention, an
intervention team considers all possible scenarios and defines
contingency plans to handle unexpected conditions. The present
compliant guide intervention technique provides the intervention
team with great flexibility in conveying a variety of intervention
tools with a variety of conveyances to the subsea installation.
[0013] By way of example, a conventional seabed "carousel system"
would require that all intervention tools for the carousel be
identified and loaded into the system before the system is lowered
to the bottom of the sea. The present technique, however, provides
a relatively simple way of conveying tools, thereby enabling the
changing of intervention tools at the surface and the conveyance of
those tools through the compliant guide to the subsea installation.
This provides intervention operations that are faster and more
efficient while reducing the risks involved with subsea connections
and disconnections. Additionally, the ability to change conveyances
also can greatly increase the efficiency of the overall
intervention operation. For example, if after gaining access to the
subsea well and attempting an intervention operation with one type
of conveyance, the intervention team may determine the operation
would be more successful with another type of conveyance. In this
scenario, the present technique allows the conveyance to simply be
changed and used with the same compliant guide rather than
requiring changing out all of the equipment involved. The use of a
single system for different conveyances also reduces deck space
requirements for the surface vessel.
[0014] Coupling a compliant guide between the subsea installation
and the surface vessel also eliminates the need for motion
compensation systems often otherwise required to compensate for the
relative movement of the surface vessel with respect to the subsea
installation. This again simplifies the operating procedures and
further reduces the deck space requirements of the surface
intervention vessel.
[0015] The use of an enclosed compliant guide also enables faster
run-in of intervention tools. The operator can run the intervention
tools to the subsea installation at higher speeds without having to
worry about the actual path followed by the tool string and the
conveyance and without having to deploy remotely operated vehicles
to guide the tool string into a lubricator of the subsea
installation. Furthermore, placement of a dynamic seal at the
bottom of the compliant guide reduces the risk of environmental
contamination. In the event a small leak passes through the dynamic
seal, the fluid is contained and isolated within the compliant
guide. Additionally, the enclosed compliant guide allows control
over the pressure within the guide through the use of surface
pressure control equipment so as to reduce the pressure
differential across the dynamic seal. This enables the construction
of a simpler dynamic seal.
[0016] The compliant guide system also lowers the risk of pollution
because the operator does not need to disconnect for each tool
change out. Furthermore, the compliant guide is capable of
resolving the problem of subsea grease injection as the use of the
compliant guide under pressure allows an operator to benefit from a
low pressure differential and thus work wit a much simpler seal
below the surface. On-surface grease injection can be utilized to
seal in high pressure differential applications.
[0017] Referring generally to FIG. 1, an intervention system 20 is
illustrated according to an embodiment of the present invention. In
this embodiment, system 20 comprises a compliant guide 22 which may
be a spoolable compliant guide. Compliant guide 22 is coupled
between a subsea installation 24 and a surface vessel 26, such as
an intervention vessel located at a surface 28 of the sea. Subsea
installation 24 may be located on or at a seabed floor 30.
[0018] Compliant guide 22 is flexible and may be arranged in a
variety of curvilinear shapes extending between intervention vessel
26 and subsea installation 24. For example, compliant guide 22 may
be arranged generally in a serpentine or S-shape that curves along
radii selected to facilitate the passage of intervention tools and
conveyances. Compliant guide 22 also may be constructed as a
tubular member formed from a variety of materials that are
sufficiently flexible, including metal materials of appropriate
cross-section and composite materials.
[0019] Once compliant guide 22 is coupled between subsea
installation 24 and intervention vessel 26, intervention tools 32
may be conveyed from intervention vessel 26 down through compliant
guide 22 and subsea installation 24 via a conveyance 34. The
compliant guide 22 also provides the path along which the
intervention tool or tools 32 can be retrieved to the surface. For
example, an intervention tool or tool string 32 can be delivered to
the subsea installation and upon completion of a specific
intervention operation, the tool 32 can be retrieved to the surface
and interchanged with another intervention tool or tool string.
This process is readily repeated as many times as necessary to
complete the entire intervention operation.
[0020] Conveyance 34 may be a flexible, cable-type conveyance, such
as a wireline or slickline. However conveyance 34 also may comprise
stiffer mechanisms including coiled tubing and coil rod. When a
cable-type conveyance 34 is used to convey intervention tool string
32, compliant guide 22 is arranged to facilitate passage of the
intervention tool string 32 without requiring a pushing force. In
other words, the curvilinear configuration of compliant guide 22 is
readily adjustable via, for example, locating intervention vessel
26 so as to avoid bends or deviated sections that could interfere
with the gravity induced passage of intervention tools 32. The
flexibility of compliant guide 22 enables its configuration to be
adjusted, if necessary, simply by moving intervention vessel 26 in
an appropriate direction, e.g. a direction as indicated by one of
the arrows 36 or 3 8. Dynamic changes can temporarily be made to
compliant guide 22 to change the shape of the compliant guide for
facilitating the passage of a tool string. In some applications, a
tractor 40 also can be used to pull the conveyance through
compliant guide 22. The tractor 40 can be included in tool string
32.
[0021] Although a variety of subsea installations 24 can be
utilized depending on the particular environment and type of
intervention operation, one example is illustrated in FIG. 1. In
this example, the subsea installation 24 comprises a subsea
wellhead 42, sometimes referred to as a Christmas tree, coupled to
a subsea well 44. Additionally, a subsea dynamic seal 46 is
positioned generally at the bottom of compliant guide 22 to help
block incursion of well fluids into an interior 48 of the compliant
guide. It should be noted that the interior 48 can be filled with a
fluid 50 which can be used, for example, to regulate the pressure
differential acting on dynamic seal 46. Also, dynamic seal 46 can
be mounted as a retrievable seal or a stationary seal that
selectively opens for passage of the tool string and selectively
closes on conveyance 34 to provide the desired seal.
[0022] In the embodiment illustrated, dynamic seal 46 is generally
positioned at the top end of a subsea lubricator 52 of subsea
installation 24. In some applications, a lower portion of compliant
guide 22 also can be utilized as part of the lubricator to enable
the use of much longer tool strings and/or a reduction in length of
subsea lubricator 52. By way of example, the dynamic seal 46 can be
attached at the lower end of compliant guide 22, or it can be
mounted at the top of the subsea lubricator 52. In some embodiments
having the dynamic seal combined with a closed environment of the
compliant guide 22 reduces or eliminates the need for a subsea
grease injection system when using a flexible conveyance 34, e.g.
an electric line or braided line conveyance. It also should be
noted that subsea lubricator 52 can be used to deploy tools that
have a relatively large outside diameter.
[0023] Subsea installation 24 also may comprise a variety of
additional components. As illustrated, subsea installation 24
comprises a lubricating valve 54 that may be deployed directly
above subsea wellhead 42. Lubricating valve 54 can be used to close
the borehole of subsea well 44 during certain intervention
operations, such as tools change outs. A blowout preventor 56 may
be positioned above lubricating valve 54 and may comprise one or
more cut-and-seal rams 58 able to cut through the interior of the
subsea installation and seal off the subsea installation during an
emergency disconnect. The subsea installation 24 also may comprise
a second blowout preventor 60 positioned above blowout preventor 56
and comprising one or more sealing rams 62 able to seal against the
conveyance 34. Additionally, an emergency disconnect device 64 may
be located at a suitable location above blowout prevent or 60.
Emergency disconnect device 64 can be used when the operator
desires to perform an emergency disconnection at the subsea
installation 24.
[0024] The compliant guide 22 also can be used in cooperation with
a variety of components that facilitate intervention operations.
Some of these components facilitate the conveyance and retrieval of
intervention tools 32 from, for example, deep water locations with
a variety of conveyances, including cable-type mechanisms. Other
components improve the longevity of the system or aid in carrying
out emergency procedures.
[0025] For example, a dynamic seal 66 can be positioned at or above
an upper end 68 of compliant guide 22. Dynamic seal 66 enables the
selective pressurization of fluid 50 disposed in interior 48 of
compliant guide 22. As described above, the ability to pressurize
fluid 50 enables, for example, control over differential pressures
exerted on subsea dynamic seal 46, thereby improving the life of
the seal and/or lowering the required functional specifications for
the seal.
[0026] An emergency disconnection device 70 also can be disposed at
upper end 68 of compliant guide 22. The emergency disconnection
device 70 comprises cut and seal capabilities to enable
disconnection from the compliant guide 22 while providing positive
pressure sealing at the upper end of the compliant guide. In this
embodiment, the emergency disconnection device 70 comprises a
buoyant member 72. A buoyant member 72 maintains upper end 68 of
compliant guide 22 suspended in the water for later retrieval by
intervention vessel 26 once the emergency disconnection situation
is over and intervention operations can resume.
[0027] One or more swivel connections also can be formed along
compliant guide 22. For some applications, the swivel connections
can be used to reduce or eliminate torque applied by compliant
guide 22 to the subsea installation 24. Additionally, the one or
more swivel connections extend the operating envelope for
intervention vessel 26. For example, the ability of compliant guide
22 to swivel enables intervention vessel 26 to adjust the
configuration of compliant guide 22 and/or to orient itself in a
desired direction. The intervention vessel can be turned to orient
itself with its bow against the wind, waves and currents and to
deploy the serpentine, i.e. S-shaped, compliant guide 22 in any
direction with respect to subsea installation 24. The desired
orientation of the compliant guide may change from one intervention
operation to another or during a given intervention operation
depending parameters, such as current, subsea obstacles, surface
obstacles and other environmental factors. By way of example, a
swivel 74 can be located proximate a bottom end 76 of compliant
guide 22, and a swivel 78 can be positioned proximate upper end 68
of compliant guide 22. One alternative configuration is to locate a
single swivel 80 generally in a middle region of compliant guide
22.
[0028] In one embodiment, compliant guide 22 is arranged to
facilitate conveyance of intervention tools 32 with cable-type
conveyances 34 by connecting upper end 68 to intervention vessel 26
and suspending a relatively long section of the compliant guide
below the intervention vessel. Closer to the bottom end 76 of
compliant guide 22, a flotation device 82 is attached to the
compliant guide to provide an upward, buoyant force. This maintains
compliant guide 22 in a generally serpentine or S-shaped
configuration conducive to the passage of intervention tools 32 to
a deep water location or other subsea installation location. The
flotation device or devices 82 maybe clamped or otherwise fastened
to the compliant guide to maintain the curvature of the compliant
guide within a desired range without creating any bends having
radii shorter than desired for suitable passage of intervention
tools 32. The flotation device or devices 82 can be designed as
bending stiffeners to further maintain a desired curvature through
at least a section of compliant guide 22. One or more bend
restrictors 84 also can be combined with compliant guide 22 to help
prevent undue bending of the compliant guide. For example, a bend
restrictor 84 can be installed on the vessel side of compliant
guide 22 proximate, for example, upper end 68. In configurations
such as those illustrated, the compliant guide 22 can be utilized
in a variety of environments without requiring tethers.
[0029] For some intervention operations, a return hose 86 (shown in
dashed lines) can be used to enable procedures that benefit from
movement of fluids. For example, return hose 86 can be used to
circulate fluids through compliant guide 22, to flush the compliant
guide, to pump tools up or down within the compliant guide, and for
other fluid based procedures. In many of these applications, the
return hose 86 is connected between the Christmas tree 42 and
appropriate fluid tanks and/or manifolds on the intervention vessel
26.
[0030] In the embodiment illustrated in FIG. 1, compliant guide 22
is used to facilitate intervention operations in a subsea well.
However, system 20 can comprise a variety of other components and
can be used in a variety of other intervention operations, e.g. an
intervention operation in a subsea flowline as illustrated in FIG.
2. In this latter embodiment, subsea installation 24 comprises a
subsea flowline head 88 instead of the subsea wellhead 42. Subsea
flowline head 88 is coupled to an appropriate subsea flowline 90.
Depending on the environment and the specific intervention
operations, a variety of other components can be incorporated into
the subsea installation 24 and or used with compliant guide 22. For
example, flotation devices 82, bend restrictors 84, return hoses
86, and other components can be used with compliant guide 22, as
described above. Additionally, a variety of other components can be
used with subsea installation 24, as illustrated in FIG. 2 and as
described above with reference to FIG. 1.
[0031] Intervention system 20 and compliant guide 22 can be adapted
to a variety of intervention operations and environments. In each
of these cases, the system enables a more efficient overall
operation and adaptation to changing parameters. The intervention
system 20 enables the interchangeability of a variety of
intervention tools and intervention conveyances. Additionally, the
system facilitates the use of cable-type conveyances and other
flexible conveyances for conveying intervention tools to a variety
of locations, including deep water locations. The configuration of
the compliant guide also can be adjusted during or between
intervention operations.
[0032] Accordingly, although only a few embodiments of the present
invention have been described in detail above, those of ordinary
skill in the art will readily appreciate that many modifications
are possible without materially departing from the teachings of
this invention. Accordingly, such modifications are intended to be
included within the scope of this invention as defined in the
claims.
* * * * *