U.S. patent application number 12/982408 was filed with the patent office on 2011-04-28 for docking and drilling stations for running self-standing risers and conducting drilling, production and storage operations.
Invention is credited to Keith K. Millheim.
Application Number | 20110094430 12/982408 |
Document ID | / |
Family ID | 40640604 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110094430 |
Kind Code |
A1 |
Millheim; Keith K. |
April 28, 2011 |
Docking and Drilling Stations for Running Self-Standing Risers and
Conducting Drilling, Production and Storage Operations
Abstract
A sea vessel exploration and production system is provided,
wherein the system includes a drilling station formed from at least
one section of a first sea vessel hull; and a docking station,
which is also formed from at least one section of a second sea
vessel hull. A mooring system suitable for connecting the drilling
station to the docking station is also provided. Means for
anchoring the vessels to the seafloor, and for attaching them to
turret buoys, are also considered. Various exploration and
production packages, as well as equipment required to deploy and
control a self-standing riser system in either deep or shallow
waters, are also described.
Inventors: |
Millheim; Keith K.; (The
Woodlands, TX) |
Family ID: |
40640604 |
Appl. No.: |
12/982408 |
Filed: |
December 30, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12274192 |
Nov 19, 2008 |
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12982408 |
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61003657 |
Nov 19, 2007 |
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Current U.S.
Class: |
114/264 ;
175/85 |
Current CPC
Class: |
B63B 21/508 20130101;
B63B 2021/003 20130101; B63B 35/44 20130101; B63B 21/507 20130101;
B63B 2035/448 20130101; B63B 35/4413 20130101; B63B 21/00 20130101;
E21B 43/013 20130101 |
Class at
Publication: |
114/264 ;
175/85 |
International
Class: |
B63B 35/44 20060101
B63B035/44; B63B 21/00 20060101 B63B021/00; B63B 21/50 20060101
B63B021/50; E21B 19/00 20060101 E21B019/00 |
Claims
1. A sea vessel exploration and production system, said system
comprising: a drilling station, wherein said drilling station
further comprises at least one section of a first sea vessel hull;
and a docking station, wherein said docking station further
comprises at least one section of a second sea vessel hull.
2. The sea vessel exploration and production system of claim 1,
further comprising a mooring system suitable for mooring said
drilling station in communication with said docking station.
3. The sea vessel exploration and production system of claim 1,
further comprising one or more anchor lines configured to position
and stabilize said drilling station and said docking station.
4. The sea vessel exploration and production system of claim 1,
further comprising a turret buoy system disposed in permissive
communication with either of said drilling station and said docking
station.
5. The sea vessel exploration and production system of claim 1,
wherein said drilling station further comprises a moon pool.
6. The sea vessel exploration and production system of claim 1,
wherein at least one of said drilling station and said docking
station further comprises a hydrocarbon testing unit.
7. The sea vessel exploration and production system of claim 1,
wherein at least one of said drilling station and said docking
station further comprises a hydrocarbon separation unit.
8. The sea vessel exploration and production system of claim 1,
wherein at least one of said drilling station and said docking
station further comprises a storage unit for storing equipment
relating to a self-standing riser system.
9. The sea vessel exploration and production system of claim 8,
wherein said equipment relating to a self-standing riser system
further comprises additional lengths of riser tubulars.
10. The sea vessel exploration and production system of claim 8,
wherein said equipment relating to a self-standing riser system
further comprises one or mote buoyancy chambers.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S.
Non-Provisional application Ser. No. 12/274,192 filed Nov. 19,
2008, still pending, which claims the benefit of prior U.S.
Provisional Application No. 61/003,657, filed Nov. 19, 2007.
FIELD OF THE INVENTION
[0002] The present invention relates generally to offshore
facilities used in connection with the exploration and production
of oil and gas, and in a particular though non-limiting embodiment,
to a docking and drilling vessel system suitable for deploying
self-standing risers and conducting oil and gas drilling,
production and storage operations.
BACKGROUND OF THE INVENTION
[0003] Offshore drilling is quickly becoming the prevalent method
of exploring and producing oil and gas, especially in Western
countries where land operations are frequently inhibited by
environmental concerns. There is, however, a serious shortfall of
offshore drilling units called Mobile Offshore Drilling Units, or
MODUs. The relative unavailability of MODUs has resulted in
significant delays in many drilling projects. Consequently, the
cost of obtaining either a new or existing MODU for an exploration
and production operation has dramatically increased over the past
decade.
[0004] As will be readily appreciated by those of skill in the art,
MODUs are utilized during the early testing phase required to
evaluate oil, gas, and other hydrocarbon discoveries. However, due
to the lack of floating production facilities and the high cost of
MODUs, early testing is seldom accomplished, which often results in
unnecessary delays and inaccurate predictions of economic
assessments, project development schedules, etc. Moreover,
procurement of offshore production and storage facilities required
to operate offshore projects in a timely manner can be quite
difficult. In extreme circumstances or in especially remote
regions, the lag time between hydrocarbon discovery and the
production phase can reach 10 years or more.
[0005] Meanwhile, self-standing riser assemblies supported by buoy
devices are becoming a more common method of performing oil and gas
exploration and production related activities. Compared to the
large scale riser assemblies typically serviced by MODUs, the
self-standing riser provides for lighter and less expensive riser
tubulars (e.g., drilling pipe, stack casing, etc.). Self-standing
risers also admit to the use of lighter blowout preventers, such as
those used by land drilling rigs.
[0006] Moreover, the top buoy of a self-standing riser system can
be positioned near the surface of the water in which it is disposed
(for example, less than around 100 ft. below surface level),
allowing for efficient drilling in even shallow waters.
Furthermore, where riser systems are tensioned and controlled with
associated buoyancy chambers, buoy-based systems can be used
successfully in much deeper waters.
[0007] However, as those of skill in the art have learned in the
field, buoy-based systems utilizing general purpose vessels for
riser and buoyancy chamber deployment are deficient in that
large-scale operations (e.g., deployment in very deep or turbulent
waters, or projects involving multiple combinations of riser
strings and buoyancy chambers, etc.) are very difficult to control,
and thus installation, operation and maintenance of the resulting
system is significantly impaired.
[0008] There is, therefore, a need for a custom vessel that admits
to efficient deployment of large-scale riser systems in a manner
similar to the manner of a MODU even when a MODU is not
available.
SUMMARY OF THE INVENTION
[0009] A sea vessel exploration and production system is provided,
wherein the system includes a drilling station formed from at least
one section of a first sea vessel hull; and a docking station,
which is also formed from at least one section of a second sea
vessel hull. A mooring system suitable for connecting the drilling
station to the docking station is also provided. Means for
anchoring the vessels to the seafloor, and for attaching them to
turret buoys, are also considered. Various exploration and
production packages, as well as equipment required to deploy and
control a self-standing riser system in either deep or shallow
waters, are also described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1A is an overhead view of a docking and drilling
station moored end-to-end, according to example embodiments.
[0011] FIG. 1B is a side view of a docking and drilling station
moored end-to-end, according to example embodiments.
[0012] FIG. 2 is a schematic diagram of an anchored drilling
station and docking station operating a self-standing riser
assembly, according to example embodiments.
[0013] FIG. 3 illustrates a sequence of steps for mooring a docking
station and a drilling station using an end-to-end method,
according to example embodiments.
[0014] FIG. 4 illustrates a sequence of steps for mooring a docking
station and a drilling station using a side-by-side method,
according to example embodiments.
[0015] FIG. 5 illustrates a sequence of steps for mooring a docking
station and a drilling station to a turret buoy anchoring assembly,
according to example embodiments.
[0016] FIG. 6 is a schematic diagram of an alternative docking
station with side-by-side docking to a docking station, according
to example embodiments.
[0017] FIG. 7 is a schematic diagram of alternative docking station
mooring schemes for varying current conditions, according to
example embodiments.
[0018] FIG. 8 is a schematic diagram of a docking station or a
drilling station attached to a turret buoy, according to example
embodiments.
DETAILED DESCRIPTION
[0019] The description that follows includes exemplary systems,
methods, and techniques that embody various aspects of the
presently inventive subject matter. However, it will be readily
understood by those of skill in the art that the disclosed
embodiments may be practiced without one or more of these specific
details. In other instances, well-known manufacturing equipment,
protocols, structures and techniques have not been shown in detail
in order to avoid obfuscation in the description.
[0020] Referring now to the example embodiment illustrated in FIG.
1A, an overhead view of a docking station 6 and a drilling station
8 are depicted as being moored together in an end-to-end manner.
The embodiment of the drilling station shown in FIG. 1B comprises
crew quarters and an operations office; a drilling rig; a void
space designed for housing and deploying various buoyancy devices;
a helipad; a moon pool; a plurality of anchor lines used to anchor
the system to an associated seabed; and mooring lines configured to
moor said drilling station and said docking station together. The
example embodiment of the docking station further comprises modular
production, testing and injection facilities; a plurality of anchor
lines; and mooring lines configured to mate with the mooring
assembly of the drilling station. A self-standing riser disposed in
mechanical communication with one or more buoyancy devices is also
provided.
[0021] In the embodiment depicted in FIG. 1A, the docking station 6
and drilling station 8 are moored together using mooring lines in
such a manner that both portions of the combined vessel are able to
properly perform offshore drilling operations. In alternative
embodiments, various other devices can be used to secure the
mooring system, for example, clamps, rods, latches, locks and other
mechanical devices; strong magnets and electrical control systems;
vacuum systems, etc.
[0022] Although not illustrated in FIG. 1, typical embodiments of
the docking and drilling stations further comprise a plurality of
oil and gas related drilling, production and exploration equipment.
For example, a modified land or platform drilling rig installed on
the drilling station can be used to operate a self standing riser
while maintaining functional stability and efficient operational
continuity. Similar equipment disposed within or upon the drilling
station 8 enables storage, deployment, lifting, and retrieval
operations, as well as storage of additional riser and one more
buoyancy devices should they be required during drilling
operations.
[0023] In further embodiments, hydrocarbons such as oil, gas,
liquid natural gas, etc., encountered during the drilling process
are separated, treated and stored either onboard or within docking
station 6. In still further embodiments, docking station 6 further
comprises modular production facilities and storage space that can
be used for testing operations or as a facility to separate oil,
gas, water, etc. Other embodiments of the docking station 6
comprise one or more of a flare boom used to bleed off gas and
fluid pressure; oil, water and gas separators; and storage
facilities used to store crude and previously treated oil and gas.
In further embodiments still, water and gas injection equipment
used to re-inject wells and the mechanical equipment required to
facilitate such operations are also included.
[0024] Since the drilling station does not necessarily have to
support deployment of conventional riser and buoyancy chamber
systems, it can utilize a typical land or platform drilling rig
modified to endure extreme sea and weather conditions. The
embodiment depicted in FIG. 2, for example, illustrates an anchored
drilling station and docking station operating in tandem to support
and control a self-standing riser system equipped with an
associated buoyancy device. The drilling station of FIG. 2 further
comprises a void space suitable for the storage and handling of
buoyancy devices, as well as a hoisting system and retractable
guide rails that assist in guiding the buoyancy devices below the
hull of drilling station.
[0025] In various other embodiments, the drilling station depicted
in FIG. 2 allows the drilling rig to hoist, lower and otherwise
handle self standing riser, casing, drilling pipe, etc., passed
through the moon pool. One specific example embodiment permits self
standing riser tubulars to be lowered into the water until a
desired length is obtained and the required quantity of buoyancy
devices are in place. Although not depicted, those of skill in the
art will appreciate that further embodiments of the drilling
station are equipped to deploy, store and handle most other types
of routine or custom fit offshore drilling equipment, such as shear
rams, ball valves, blowout preventers and hoists therefor.
[0026] Following installation of the self standing riser, the
drilling station can commence drilling, completion, testing and
workover operations, etc. As operations continue, some portions of
the system can be removed so that the drilling station can be
utilized in other types of operations. In further embodiments, the
drilling station is utilized to drill a hole in a seabed so as to
permit installation of a wellhead and associated casing. In still
further embodiments, the drilling station is used to remove and
store the riser assemblies, as well as attendant buoyancy devices
and other offshore drilling equipment.
[0027] In some example embodiments, the described installation and
removal process is applied to wellheads created by others and
abandoned. Such projects would typically utilize cranes, hoists,
winches, etc., operating in mechanical communication with the
drilling station in order to perform installation and removal of
existing riser assemblies, wellheads, production trees and blowout
preventers.
[0028] In some embodiments, the void space formed to store and
handle buoyancy devices further comprises a moveable floor, tracks,
a gantry, etc., that transports buoyancy devices to a desired
location (e.g., near the moon pool) to be joined with a self
standing riser assembly stack. Various embodiments of the moon pool
further comprise retractable guide rails that assist in guiding and
delivering the buoyancy devices down below the hull to a deployment
station.
End-to-End and Side-to-Side Mooring of the Docking and Drilling
Stations
[0029] FIGS. 3 and 4 depict an embodiment of the docking station
and the drilling station moored together using end-to-end and
side-to-side mooring methods, respectively.
[0030] In the example embodiment illustrated in Step 1 of both
FIGS. 3 and 4, docking station is towed by a towing vessel toward
anchor lines preinstalled by workboats, anchor handling vessels,
etc. Towing of the docking and drilling stations can of course be
facilitated by any vessel capable of towing another vessel of
appropriate size, such as a work boat, a tug, etc.
[0031] Step 2 depicts various transportation vessels (e.g.,
workboats, towing vessels, etc.) transporting a plurality of anchor
lines to fastening members disposed in communication with the
docking station. Some embodiments of the fastening members assist
in adding tension to the anchor lines, and slowly moving the
docking station toward desired site coordinates.
[0032] In the end-to-end embodiment shown in FIG. 3, the anchor
lines are affixed to fastening members positioned on all sides of
the docking station. Note, however, that the anchor lines would
typically be affixed to fastening members on a particular side of
the docking station in the side-to-side method depicted in Step 2
of FIG. 4. Such embodiments of side-to-side mooring help maintain
proper lateral spacing and controlled efficient movement as the
drilling station and docking station are joined. In further
embodiments, the drilling station 8 is transported to within a
close proximity of the docking station 6 during Step 2, and a
plurality of anchor lines are thereafter affixed to fastening
members of the drilling station in order to secure the system in a
desired dynamic equilibrium.
[0033] Step 3 illustrates the drilling station as disposed in
stable operative communication with the docking station. Various
known attachment means, such as mooring lines, as well as any new
or custom designed fasteners or the like can be used to facilitate
stable and reliable operations. In the embodiment depicted in FIG.
3, the drilling station and the docking station are mutually joined
and operated in a back-to-back or end-to-end manner, whereas in the
embodiment illustrated in FIG. 4, the drilling station and the
docking station are joined in a side-to-side manner. Either manner
will, if configured correctly, permit the drilling station to
drill, deploy casing, deploy self standing riser tubulars, etc. In
some embodiments, the drilling station is configured to position
itself over an existing self standing riser system in order to
perform workover operations, well completions, and other common
drilling operations.
[0034] In the embodiment illustrated in Step 4 of FIGS. 3 and 4,
the drilling station is disconnected from the docking station and
towed away. In a typical example embodiment, anchoring lines
previously used to anchor the drilling station in place are
attached to the remaining docking station, thereby resulting in a
spread mooring configuration suitable for receiving a new vessel.
In some embodiments, the docking station is then used as a testing
or production vessel to process and separate oil, gas and water,
etc. In further embodiments, the docking station provide facilities
to inject water and gas back into well(s), power to operate
electric submersible pumps, or lifting support to aid with other
production methods.
[0035] Step 5 depicts an embodiment of the mooring sequence in
which an oil tanker is joined in communication with the docking
station. As previously discussed, example embodiments may comprise
a wide variety of attachment methods and means, such as mooring,
docking, fastening, etc. In one example embodiment, the docking
station then utilizes pipes, tubulars, hoses, etc., to transfer
oil, gas or other stored fluids to and from the tanker.
End-to-End Mooring Using a Turret Buoy
[0036] FIG. 5 depicts an embodiment of a turret buoy mooring
process that allows the drilling station and the docking station to
cooperate in a synchronized manner even in very poor weather
conditions, such as strong winds, rough currents, etc. In the
embodiment illustrated in Step 1 of FIG. 5, conventional mooring
lines and anchors are affixed to a turret buoy as known in the art.
Embodiments of the drilling station are subsequently towed to the
turret buoy, as illustrated in Step 2. In the embodiment depicted
in Step 3, a plurality of towing vessels position the drilling
station in relatively close proximity to the turret buoy, where the
drilling station and the turret buoy are mutually joined. In Steps
4 and 5, the docking station is similarly joined to the system in
accord with the principles previously discussed above. In one
specific embodiment, the drilling station is also capable of
performing a multitude of other offshore drilling functions,
including deployment and operation of drilling equipment; the
drilling of holes on the seabed and installation of casing;
deployment and operation of self-standing riser, etc.
[0037] In the embodiments illustrated in Step 5 and Step 6, the
docking station is moved to a location and attached in
communication with the turret buoy after completion of operations
by the drilling station. In further embodiments, the drilling
station is then removed from the turret buoy to allow for
attachment of the docking station so that testing and production
can commence.
Side-by-Side Mooring Using a Spread Mooring System
[0038] Referring now to the example embodiment depicted in FIG. 6,
the docking station and drilling station are joined using a
side-by-side mooring system. Various embodiments of the drilling
station are affixed to the docking station using a system of
attachment mechanisms, such as mooring, docking, fastening devices,
etc., which lend support and provide rigid separation in the
lateral direction while still allowing mutual vertical movement. In
one embodiment, conventional mooring with anchor lines can secure
the drilling station and docking station in proximity of a
self-standing riser. Several embodiments of side-by-side mooring
utilize hydraulically compensated cylinders to maintain constant
lateral distance and compensate for wave and swell actions. For
example, embodiments using a hydraulically compensated cylinder can
maintain separation forces while dampening related transient forces
caused by wave and swell movement.
End-to-End and Side-by-Side Mooring of the Drilling Station and
Docking Station Using the Turret Moored Buoy
[0039] Referring now to the example embodiment in FIG. 7,
side-by-side and end-to-end mooring configurations of the drilling
station and docking station attached in communication with a turret
buoy is illustrated. In some embodiments, the turret buoy is
utilized for situations where a particular area of the water has
significantly varying or conflicting currents. In further
embodiments, the turret buoy is designed to be attached to a
self-standing riser, while relative positioning of the drilling
station and docking station is maintained. According to still
further embodiments, the design of the turret buoy varies depending
on the dimensions of the docking or drilling stations, or in
conformity with the dimensions of the moon pool.
[0040] In some embodiments, the drilling station and the docking
station attach to the turret buoy using mechanical or hydraulic
couplers or other fastening devices known in the art. In the
embodiment illustrated in FIG. 8, the turret buoy allows for a 360
degree rotation of the particular station with which it is
disposed. For example, the docking station can rotate 360 degrees
once it is attached to the turret buoy.
[0041] In some example embodiments utilizing a turret buoy, the
drilling station is moored first, and used to perform one or more
of drilling, deployment, workover, completion, testing, etc.,
operations. In other embodiments, the docking station is moored to
the drilling station, and used to conduct one or more of the
aforementioned operations, as depicted in FIG. 8. Once the work of
drilling station is concluded, it is detached from the turret buoy
while the docking station remains behind for continued
operations.
[0042] The foregoing specification is provided for illustrative
purposes only, and is not intended to describe all possible aspects
of the present invention. Moreover, while the invention has been
shown and described in detail with respect to several exemplary
embodiments, those of ordinary skill in the art will appreciate
that minor changes to the description, and various other
modifications, omissions and additions may also be made without
departing from the spirit or scope thereof.
* * * * *