U.S. patent application number 13/363412 was filed with the patent office on 2012-06-21 for universal subsea oil containment system and method.
Invention is credited to George Carter, Michael Volk.
Application Number | 20120155964 13/363412 |
Document ID | / |
Family ID | 46234640 |
Filed Date | 2012-06-21 |
United States Patent
Application |
20120155964 |
Kind Code |
A1 |
Carter; George ; et
al. |
June 21, 2012 |
Universal Subsea Oil Containment System and Method
Abstract
A system, method, and apparatus for containing oil and gas
leaking from an underwater wellhead or other man-made structure.
The apparatus includes a conduit having an upper end and a lower
end with an opening. The conduit is sized for the lower end to be
positioned over a plume leaking from the man-made structure and the
upper end to be substantially near or at the seawater surface. The
apparatus also includes a port for introducing a suitable gas such
as nitrogen into the interior of the conduit for displacing
seawater from the interior of the conduit. In addition, the
apparatus includes a plurality of valves for metering liquid and
gas flow within the interior of the conduit. The conduit is
positioned over the leaking man-made structure and oil and gas flow
upward from the leaking man-made structure through the interior of
the conduit.
Inventors: |
Carter; George; (Lucas,
TX) ; Volk; Michael; (Tulsa, OK) |
Family ID: |
46234640 |
Appl. No.: |
13/363412 |
Filed: |
February 1, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13162666 |
Jun 17, 2011 |
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13363412 |
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61358697 |
Jun 25, 2010 |
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13162666 |
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Current U.S.
Class: |
405/60 |
Current CPC
Class: |
E21B 43/0122 20130101;
E02B 2015/005 20130101 |
Class at
Publication: |
405/60 |
International
Class: |
E02B 15/00 20060101
E02B015/00 |
Claims
1. A system of containing oil and gas leaking from an underwater
man-made structure, the system comprising: a conduit positioned
over a plume leaking from the man-made structure; the conduit
having an upper end located at or substantially near a seawater
surface and a lower end positioned over the leaking man-made
structure, the lower end having an opening leading to an interior
of the conduit; means for creating a pressure differential between
a pressure within the interior of the conduit and a pressure
outside the conduit to induce an upward flow of fluids within the
interior of the conduit, the interior pressure of the conduit being
below the pressure outside the conduit; means for expelling liquid
from the interior of the conduit; means for releasing gas from the
interior of the conduit; means for introducing a suitable gas into
the interior of the conduit for displacing seawater from the
interior of the conduit; a plurality of valves for metering liquid
and gas flow within the interior of the conduit; whereby liquid and
gas flow upward from the leaking man-made structure through the
interior of the conduit and are removed from the interior of the
conduit.
2. The system according to claim 1 wherein the upper end of the
conduit includes a containment tank.
3. The system according to claim 2 wherein the containment tank
includes a Gas/Liquid Cylindrical Cyclone (GLCC).
4. The system according to claim 3 wherein the containment tank
includes a port for injecting monoethylene glycol (MEG), methanol
or other chemical into the interior of the containment tank.
5. The system according to claim 2 wherein the means for creating a
pressure differential includes means for pumping any liquid located
in the containment tank out of the containment tank.
6. The system according to claim 2 wherein the means for releasing
gas is a gas release tube coupled to the containment tank.
7. The system according to claim 6 wherein the gas release tube
releases gas above the seawater surface.
8. The system according to claim 2 wherein the means for expelling
liquid from the interior of the conduit includes: a liquid ejection
tube coupled to the containment tank for expelling the liquid from
the interior of the conduit; and a pump for pumping the liquid from
the interior of the conduit.
9. The system according to claim 1 wherein the plurality of valves
includes an upper valve located near the upper end of the conduit
and a lower valve located at the lower end of the conduit.
10. The system according to claim 1 wherein the means for
introducing a suitable gas into the interior of the conduit is a
port for injecting the suitable gas from outside the conduit into
the interior of the conduit.
11. The system according to claim 1 wherein the conduit is
constructed of two or more sections coupled together.
12. The system according to claim 11 wherein each section includes
at least one valve for metering liquid and gas within the interior
of the conduit.
13. The system according to claim 1 wherein the lower end includes
an induction bell for gathering leaking hydrocarbons from the
man-made structure.
14. The system according to claim 13 wherein the induction bell
includes a port for injecting a suitable gas into the interior of
the conduit.
15. The system according to claim 1 wherein the conduit includes a
double wall providing thermal insulation to the conduit.
16. A method of containing oil and gas leaking from an underwater
man-made structure, the method comprising the steps of: closing one
or more valves within an interior of a conduit; injecting a
suitable gas into the interior of the conduit; positioning a
conduit over a plume leaking from the man-made structure, the
conduit having an upper end located at or substantially near the
seawater surface and a lower end having an opening leading to an
interior of the conduit; opening one or more valves to meter liquid
and gas through the interior of the conduit; pumping liquid from an
upper portion of the interior of the conduit to reduce an interior
pressure of the conduit below a pressure outside the conduit to
induce an upward flow of fluids within the interior of the conduit;
and expelling gas located within the interior of the conduit
through a gas release tube coupled to an interior of the
conduit.
17. The method according to claim 16 wherein: the step of closing
one or more valves includes closing all valves for configuring the
conduit in a closed configuration; and the step of injecting a
suitable gas into the interior of the conduit includes injecting a
gas as the conduit is submerged into the seawater.
18. The method according to claim 15 wherein: the step of closing
one or more valves includes leaving at least one valve open for
configuring the conduit in an open configuration; and the step of
injecting a suitable gas into the interior of the conduit includes
injecting a gas after the conduit is submerged to displace the
seawater from the interior of the conduit.
19. The method according to claim 16 wherein the upper portion of
the conduit includes a containment tank and the step of pumping
liquid from an upper portion includes pumping liquid located within
the containment tank out of the conduit.
20. The method according to claim 16 wherein the step of injecting
a suitable gas includes injecting nitrogen into the interior of the
conduit.
21. The method according to claim 16 further comprising the step of
injecting a suitable gas into an interior of an induction bell, the
induction bell being located at the lower end of the conduit.
22. The method according to claim 21 further comprising the step of
injecting mono-ethylene glycol (MEG), methanol, other chemical into
a cavity surrounding the induction bell.
23. An apparatus for containing oil and gas leaking from an
underwater man-made structure, the apparatus comprising: a conduit
having an upper end and a lower end with an opening, the conduit
being sized for the lower end to be positioned over a plume leaking
from the man-made structure and the upper end to be substantially
near or at a seawater surface; a containment tank located in the
upper portion of the interior of the conduit; a first tube for
pumping liquid located within the containment tank out of the
interior of the conduit, thereby creating a pressure differential
between a pressure within the interior of the conduit and a
pressure outside the conduit to induce an upward flow of fluids,
within the interior of the conduit, the interior pressure of the
conduit being below the pressure outside the conduit; a second tube
for releasing gas from the interior of the conduit; a port for
introducing a suitable gas into the interior of the conduit for
displacing seawater from the interior of the conduit; a plurality
of valves for metering liquid and gas flow within the interior of
the conduit; whereby the conduit is positioned over the leaking
man-made structure and liquid and gas flow upward from the leaking
man-made structure through the interior of the conduit.
24. The system according to claim 23 wherein: the lower end
includes an induction bell for gathering leaking hydrocarbons from
the man-made structure; and the induction bell includes a port for
injecting a suitable gas into the interior of the conduit.
25. The system according to claim 23 wherein the conduit includes a
double wall providing thermal insulation to the conduit.
Description
RELATED APPLICATIONS
[0001] This utility application is a continuation-in-part
application of co-pending U.S. patent application Ser. No.
13/162,666 entitled "Universal Subsea Oil Containment System and
Method" filed on Jun. 17, 2011 under the name of George Carter
which claims the benefit of U.S. Provisional Patent Application
Ser. No. 61/358,697 filed Jun. 25, 2010 and is hereby incorporated
by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to oil and gas systems. Specifically,
and not by way of limitation, the present invention relates to a
system and method in some scenarios, however, there are blowout
scenarios were leaks develop outside the well casing, or leaks
develop from the BOP or a damaged connector. Ideas have arisen to
"drop" a containment device over the source of the spill, but
containment domes have had limited success in shallow seawater and
have never worked in deepwater environments. A dome-like design,
with the open end attempting to seal to ocean floor sediment and
debris, is inherently flawed. A new approach is needed to match the
task of potential spill cleanup with the realities of deepwater and
ultra-deepwater drilling.
[0004] Pending U.S. patent application Ser. No. 13/162,666
discloses a novel solution which can capture and contain oil and
gas leaking from leaks originating from man-made structures at deep
underwater depths. Specifically, U.S. patent application Ser. No.
13/162,666 discusses an apparatus and method which includes a
conduit having an upper end and a lower end with an opening. The
conduit is sized for the lower end to be positioned over a plume
leaking from the man-made structure and the upper end to be
substantially near or at the seawater surface. In addition, a
containment tank is located in the upper portion of the interior of
the conduit. The apparatus also includes a first tube for pumping
liquid located within the containment tank out of the interior of
the conduit, thereby creating a pressure differential between a
pressure within the interior of the conduit and a pressure outside
the conduit to induce an upward flow of fluids within the conduit.
The interior pressure of the conduit is lower than the pressure
outside the conduit. The apparatus also includes a second tube for
releasing gas from the interior of the conduit.
[0005] However, natural gas hydrate formation due to high pressure
and cold seawater is a critical problem. It would be advantageous
to have a system and method of initiating a flow through the system
which reduces hydrate formation by reducing the presence of
seawater within the conduit of containing hydrocarbons, such as oil
and gas, from underwater leaks from man-made structures.
[0006] 2. Description of the Related Art
[0007] Recently, oil and gas companies have been initiating
deepwater drilling for capturing oil and gas resources. With the
high revenues associated with selling these natural resources,
these companies have found it economically viable for using
deepwater drilling techniques to capture these oil and gas
resources. However, with the use of deepwater drilling, there have
been several problems. One such problem occurred in 2010 with the
Macondo well blowout in the Gulf of Mexico which caused the
destruction of the Deepwater Horizon rig, sadly resulting in loss
of life, and was the source of the largest offshore oil spill in
U.S. history. The United States government's estimate was that 172
million gallons of oil spilled into the ocean in a period of
approximately three months. The National Commission on the BP
Deepwater Horizon Oil Spill and Offshore Drilling indicated that
both the industry and government were unprepared for such a spill
and that deepwater operators need to have detailed source control
plans to respond to blowouts.
[0008] According to a report by the National Academy of
Engineering, the rapid development of new technologies for
deepwater drilling have surpassed the regulations expected to
evaluate and oversee the industry's safety practices. The BP oil
spill exposed the roughly thirty-year technology gap that exists in
current methods to cleanup and contain an offshore oil spill,
particularly in ultra-deepwater.
[0009] Currently, when a wellhead leaks oil and gas, there are
limited solutions for alleviating or terminating the leak at deep
depths of seawater. The Marine Well Containment Company and Helix
Energy Solutions Group have developed leak remediation plans that
use equipment that directly contacts by capping or connecting to
the BOP. These are useable solutions and maintains the integrity of
the conduit utilized in subsea environment. It is an object of the
present invention to provide such a system and method.
SUMMARY OF THE INVENTION
[0010] In one aspect, the present invention is directed to an
apparatus for containing oil and gas leaking from an underwater
man-made structure. The apparatus includes a conduit having an
upper end and a lower end with an opening. The conduit is sized for
the lower end to be positioned over a hydrocarbon plume leaking
from the man-made structure and the upper end to be substantially
near or at the seawater surface. In addition, a containment tank is
located at the upper portion of the interior of the conduit. The
apparatus also includes a first tube for pumping liquid located
within the containment tank out of the interior of the containment
tank and conduit, thereby creating a pressure differential between
a pressure within the interior of the conduit and a pressure
outside the conduit to induce an upward flow of fluids within the
conduit. The interior pressure of the conduit is lower than the
pressure outside the conduit. The apparatus also includes a second
tube for releasing gas from the interior of the conduit. The
apparatus also includes a port for introducing a suitable gas such
as nitrogen into the interior of the conduit to displace water. In
addition, the apparatus includes a plurality of valves for metering
liquid and gas flow within the interior of the conduit. The conduit
is positioned over the leaking man-made structure and liquid and
gas flow upward from the leaking man-made structure through the
interior of the conduit.
[0011] In another aspect, the present invention is directed to a
method of containing oil and gas leaking from an underwater
man-made structure. The method begins by closing one or more valves
within an interior of a conduit. A suitable gas is injected into
the interior of the conduit. Next, a conduit is positioned over a
hydrocarbon plume leaking from the man-made structure. The conduit
has an upper end located at or substantially near the seawater
surface and a lower end having an opening leading to an interior of
the conduit. Next, one or more of the values are opened to meter
liquid and gas through the interior of the conduit. Liquid
contained in the interior of the conduit is then pumped out from an
upper portion of the conduit to reduce an interior pressure of the
conduit below a pressure outside the conduit to induce an upward
flow of fluids. Gas is released through a gas release tube coupled
to an interior of the conduit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a side view of a containment system in one
embodiment of the present invention;
[0013] FIG. 2 is a side view of a containment system in another
embodiment of the present invention;
[0014] FIG. 3 is an enlarged side view illustrating the induction
bell; and
[0015] FIGS. 4A and 4B are flow charts illustrating the steps of
containing and capturing oil and gas from a leaking structure using
a conduit in a closed configuration; and
[0016] FIGS. 5A and 5B are flow charts illustrating the steps of
containing and capturing oil and gas from a leaking structure using
a conduit in an open configuration.
DESCRIPTION OF THE INVENTION
[0017] The present invention is a system and method of capturing
and containing oil and gas leaking from an underwater man-made
structure. FIG. 1 is a side view of a containment system 10 in one
embodiment of the present invention. The containment system 10
includes a main conduit 12 having a first lower end 14 with an
opening 16 and an opposite second upper end 18 with a containment
tank 20. In one embodiment, the containment tank may be located
below a seawater surface 22. In this embodiment, the containment
tank may be coupled to a gas release tube 24 leading to the surface
22. The tube 24 may lead to an aperture 26 opened to the outside
above-water environment 28 or to a man-made structure such as a
ship (not shown). Flow control devices, such as fixed (e.g.,
Venturi) or variable (e.g., valves) may be used to control the flow
of the gas exiting the tube. The containment tank may also include
a second liquid ejection tube 30 having a pump (not shown) leading
to the surface 22 and a capture vessel or other man-made structure
(not shown). In an alternate embodiment, the containment tank may
extend above the seawater surface 22.
[0018] In addition, the containment system 10 includes a base
section 32 having the lower opening 16 coupled to the lower end 14
of the main conduit. The base section 32 may include an induction
bell 34 having a diameter larger than the diameter of the main
conduit 12. A dissociation zone 36 may be located in an interior of
the conduit where gas-hydrates are dissociated or melted.
Gas-hydrates may also form within interior the conduit in a
gas-hydrate formation zone 84. The base section may be affixed to a
sea floor 38 by any mechanism which allows the containment system
to remain stationary over a plume (leak) originating from a
man-made structure, such as a damaged blowout prevent (BOP) 40. In
one embodiment, the base structure is attached to a plurality of
base pylons 42 embedded into the sea floor 38. Preferably, the
attachment mechanism includes at least three base pylons having
cables 44 affixed to an attachment station 46. The cables may be
lengthened or shortened to move the main conduit laterally or
vertically in relation to a leak plume 50. In the preferred
embodiment of the present invention, the main conduit may include
floatation collars (not shown) or other floatation devices to allow
the main conduit to float underwater. The cables are used to attach
the base structure and main conduit to the pylons. In other
embodiments, the present invention may use other attachment devices
(e.g., rigid arms) to retain the main conduit underwater and close
to the leak. In the preferred embodiment of the present invention,
the induction bell is positioned above the plume 50 with a vertical
space 54. In addition, the open vertical space enables a space
around the BOP 40 to be accessed by remote underwater devices such
as Remotely Operated Vehicles (ROVs), which may be necessary when
operators are attempting to repair the leaking structure while
still capturing leaking oil and gas.
[0019] The interior 52 of the main conduit 12 may include a
multi-phase flow zone for oil, gas-hydrates, natural gas, chemicals
(such as monoethylene glycol (MEG)) and seawater. In the preferred
embodiment of the present invention, the main conduit has a
diameter A no larger than a standard 21 inch riser. This enables
ease in constructing and assembling the containment system
utilizing currently used parts and machinery. An upper section 60
of the main conduit may have a large diameter B in comparison to
the main conduit to allow expansion from hydrate dissociation. In
addition, in other embodiments, there may be many stages of
increasingly greater diameters along the span of the conduit.
[0020] The conduit may be constructed of any material which may
contain a liquid (e.g., liquid-tight). Furthermore, the
cross-section of the conduit may be any shape. In addition, an
interior wall of the conduit may be coated with an epoxy, an
epoxy-like material or any other composite material to reduce the
adhesive qualities of hydrates to the interior wall. Additionally,
the conduit may include a double wall providing thermal insulation.
By maintaining or increasing the temperature of the fluids within
the conduit, hydrate formation is reduced. In one embodiment, the
conduit is sized in the conduit's length to enable the conduit to
be positioned over the plume 50 and still reach near (relative to
the depth of the seawater and length of the conduit) or at the
seawater surface. The conduit may be constructed in sections to
accommodate varying depths from the surface to a wellhead. The
conduit diameter is large enough to prevent clogging from
gas-hydrates and allow for dissociation of hydrates and expansion
of natural gas.
[0021] The induction bell 34 may include ports for injecting MEG,
methanol, anti-agglomerant, or other chemicals into the interior of
the conduit. The expanding natural gas and fluid rises up through
the conduit into the containment tank 20. A liquid level 64 in the
containment tank is adjustable depending on the rate the fluid that
is pumped out of the liquid ejection tube 30.
[0022] A pump (not shown) may be used to pump out the oil and fluid
within the containment tank 20 through the liquid ejection tube 30
to a tanker or other storage facility located above seawater. This
fluid may be stored in a tanker (not shown) through an exit point
70. The fluid is pumped out to maintain the liquid level 64 below
the seawater surface 22. This provides a pressure differential 62
between the interior of the conduit and outside seawater pressure
which induces an upward flow of fluids (i.e., seawater, oil, and
gas). Specifically, by pumping out the fluid, the liquid level 64
inside the conduit, in the containment tank, is maintained below
the seawater surface, thereby keeping pressure in an interior 80
lower than outside 82 (underwater) at any given depth of the
conduit. It should be understood that a conduit may be any device
having a passageway or channel which can contain, funnel or channel
the escaping gas and oil from the wellhead to the surface. Although
the term conduit is used, the present invention is not limited to
tubular or pipe-like devices and may be configured in any size and
shape. In addition, the tubes referred to in the liquid ejection
tube and gas release tube may be any conduit or device allowing the
transfer of oil and gas out of the interior of the conduit.
[0023] FIG. 2 is a side view of a containment system 100 in another
embodiment of the present invention. The containment system 100 of
FIG. 2 may be used in the same manner as the containment system 10
and may contain various modifications from the system of FIG. 1.
The container system 100 may include a main conduit 112 having a
first lower end 114 with an opening 116 and an opposite second
upper end 118 with a containment tank 120. The containment tank 120
may include a Gas/Liquid Cylindrical Cyclone (GLCC) commonly used
in the oil and gas industry which provides optimum gas-liquid
separation performance. In one embodiment, the containment tank may
be located below a seawater surface 22. In this embodiment, the
containment tank may be coupled to a gas release tube 124 leading
to the surface 22. The tube 124 may lead to an aperture 126 opened
to the outside above-water environment 28 or to a man-made
structure such as a ship (not shown). The containment tank may also
include a second liquid ejection tube 130 having a pump (not shown)
leading to the surface 22 and a capture vessel or other man-made
structure (not shown). In an alternate embodiment, the containment
tank may extend above the seawater surface 22.
[0024] In addition, the containment system 100 includes a base
section 132 having the lower opening 116 coupled to the lower end
114 of the main conduit. The base section 132 may include an
induction bell 134 having a diameter larger than the diameter of
the main conduit 112. Gas-hydrates may form within the interior of
the conduit in a gas-hydrate formation zone 184. The base section
may be affixed to a sea floor 38 by any mechanism which allows the
containment system to remain stationary over a plume (leak)
originating from a man-made structure, such as a damaged blowout
prevent (BOP) 40. In one embodiment, the base structure is attached
to a plurality of base pylons 42 embedded into the sea floor 38.
Preferably, the attachment mechanism includes at least three base
pylons having cables 44 affixed to an attachment station 46. The
cables may be lengthened or shortened to move the main conduit
laterally or vertically in relation to a leak plume 50. The plume,
BOP and base components are not shown in FIG. 2, although the
containment system 100 may or may not include such components as
depicted in FIG. 1. The main conduit may include floatation collars
(not shown) or other floatation devices to allow the main conduit
to float underwater. The cables are used to attach the base
structure and main conduit to the pylons. In other embodiments, the
present invention may use other attachment devices (e.g., rigid
arms) to retain the main conduit underwater and close to the
leak.
[0025] The interior 152 of the main conduit 112 may include a
multi-phase flow zone for oil, gas-hydrates, natural gas, and
seawater. The percentage of seawater is controlled by adjusting the
pressure differential. In one embodiment of the present invention,
the main conduit has a diameter A no larger than a standard 21 inch
riser. This enables ease in constructing and assembling the
containment system utilizing currently used parts and machinery. In
one embodiment of the present invention, there may be many stages
of increasingly greater diameters along the span of the
conduit.
[0026] The conduit may be constructed of any material which may
contain a liquid (e.g., liquid-tight). Furthermore, the
cross-section of the conduit may be any shape. In addition, an
interior wall of the conduit may be coated with an epoxy, an
epoxy-like material or any other composite material to reduce the
adhesive qualities of hydrates to the interior wall. In one
embodiment, the conduit is sized in the conduit's length to enable
the conduit to be positioned over the plume 50 and still reach near
(relative to the depth of the seawater and length of the conduit)
or at the seawater surface. The conduit may be constructed in
sections to accommodate varying depths from the surface to a
wellhead. The conduit diameter is large enough to prevent clogging
from gas-hydrates and allow for dissociation of hydrates and
expansion of natural gas as the gas-hydrates rise toward the
surface where the gas is separated from the liquid.
[0027] The induction bell 134 may include ports for injecting
anti-agglomerant, or other chemicals into the interior of the
conduit. The expanding natural gas and liquid rises up through the
conduit into the containment tank 120. A liquid level 164 in the
containment tank is adjustable depending on the rate the fluid is
pumped out of the liquid ejection tube 130.
[0028] A pump (not shown) may be used to pump out the contained oil
and liquids within the containment tank 120 through the liquid
ejection tube 130 to a tanker or other storage facility located
above sea level. This liquid may be stored in a tanker (not shown)
through an exit point 170. The liquid is pumped out to maintain the
liquid level 164 below the seawater surface 22. This provides a
pressure differential 162 between the interior of the conduit and
outside seawater pressure which induces an upward flow of fluids
(i.e., seawater, oil, and gas). Specifically, by pumping out the
liquid, the liquid level 164 inside the conduit, in the containment
tank, is maintained below the seawater surface, thereby keeping
pressure in an interior 180 lower than outside 82 (underwater) at
any given depth of the conduit. It should be understood that a
conduit may be any device having a passageway or channel which can
contain, funnel or channel the escaping gas and oil from the
wellhead to the surface. Although the term conduit is used, the
present invention is not limited to tubular or pipe-like devices
and may be configured in any size and shape. In addition, the tubes
referred to in the liquid ejection tube and gas release tube may be
any conduit or device allowing the transfer of oil and gas out of
the interior of the conduit.
[0029] Flow control devices, such as fixed (e.g., Venturi) or
variable (e.g., valves) may be used to control the flow of the gas
exiting the tube. As depicted in FIG. 2, the containment system 100
includes a lower valve 190 controlling the opening 116, an upper
valve 192 at a lower end of the containment tank 120, a valve 194
in the liquid ejection tube 130 and a valve 196 in the gas release
tube 124. It should be understood that the valves may be located
anywhere and still remain in the scope of the present invention.
The valves are also utilized to contain an injection of a gas, such
as nitrogen into the interior of the conduit. As discussed, the
conduit may include several sections. Each section may include an
upper and lower valve located at each end of the section. In
addition, the conduit may include one or more gas ports 200. A gas
port may be located in each section of a staged conduit.
Additionally, the induction bell 134 may include a gas port
202.
[0030] FIG. 3 is an enlarged side view illustrating the induction
bell 134. The induction bell may include insulation 210.
Additionally, the induction bell may include a cover shell 212
having a heated cavity 214. A gas port 216 leading to the cavity
214 may allow the introduction of MEG, methanol, or other chemical
into the cavity. A discharge slot 220 may be utilized for
discharging the MEG, methanol, or other chemical from the
cavity.
[0031] With reference to FIGS. 1-3, the operation of the
containment system 100 will now be explained. In a first embodiment
of the present invention, the valves 190 and 192 are closed to the
conduit 112 or a specific section of the conduit. This first
embodiment is also known as the "dry" embodiment. The conduit or
section of conduit is submerged into the seawater. As the conduit
descends, a gas such as nitrogen is introduced through the port 200
into the interior 152 of the conduit. The introduction of the gas
provides an internal pressure to the conduit, thereby enhancing the
structural integrity of the conduit and preventing pressure from
the surrounding seawater from crushing the conduit. In most cases
where the depth of the lowest end of the conduit is less than
approximately 8000 feet, the use of nitrogen is acceptable. In
particular, when utilizing nitrogen, hydrates of nitrogen do not
form where pressure is approximately 8000 feet of seawater or less.
The conduit may still be lowered below 8000 feet seawater pressure
with the internal pressure of the conduit remaining at
approximately 8000 feet of seawater, which is of a sufficient
outward pressure to retain the structure integrity of the conduit
and counteract the inward pressure from the seawater on the
conduit. If the conduit is constructed in sections, each section
may include upper and lower valves to prevent passage of seawater
into the section's interior. Additionally, each section may include
a port to introduce the gas (e.g., nitrogen) into the interior of
the section. The sections are added to the conduit as needed to
provide a length of the conduit as necessary for the required depth
to the plume.
[0032] The conduit is eventually positioned near the plume 50 from
a leaking wellhead, man-made structure, BOP 40 or where the leak
emanates (e.g., seafloor). The conduit may be moved laterally to
position the opening 116 of the conduit directly over the plume 50.
The appropriate valves are then opened as necessary to meter a
portion of the leaking hydrocarbons (fluids, which includes gas and
liquid) through the interior of the conduit. After the flow of the
fluids progresses upward, the valves may be configured as necessary
to allow passage of a majority, or all of the leaking fluid through
the interior of the conduit. Furthermore, after startup of the flow
of fluids in the conduit, the introduction of gas (nitrogen) is
discontinued into the conduit. As gas and oil (hydrocarbons) escape
from the wellhead, the oil and gas travels up the conduit 112. The
liquid (e.g., oil and seawater) is pumped out of the conduit to a
storage area, such as a tanker through the liquid ejection tube
130. Furthermore, the natural gas contained in the containment tank
120 may be released through the gas release tube 124 where the
natural gas may be contained or flared. The liquid level 164 is
maintained below the seawater surface 22. The escaping oil and gas
emitted from the wellhead rise through the conduit where the liquid
is pumped out the liquid ejection tube 130 and gas is released
through the release tube respectively. The startup of the flow of
fluids through the conduit provides for minimal flow of seawater
through the interior of the conduit, thereby reducing the formation
of hydrates in the interior of the conduit.
[0033] In a second embodiment of the present invention, the conduit
is submerged in an open configuration where the lower valve 190 is
opened and the upper valve 192 is closed prior to entering the
seawater. This second embodiment is also known as the "wet"
embodiment. The nitrogen or other suitable gas may then be
introduced into the interior through the port 200 when the conduit
or section is submerged. The nitrogen gas displaces the seawater in
the interior of the conduit out through the valve 190. After
injecting the nitrogen into the interior of the conduit, the
conduit is eventually positioned near the plume 50 from a leaking
wellhead, man-made structure, BOP 40 or where the leak emanates
(e.g., seafloor). The conduit may be moved laterally to position
the opening 116 of the conduit directly over the plume 50. In a
similar manner as the dry embodiment, the appropriate valves are
then opened as necessary to meter a portion of the leaking
hydrocarbons (fluid, which includes gas and liquid) through the
interior of the conduit. After the flow of the fluids progresses
upward, the valves may be configured as necessary to allow passage
of a majority or all of the leaking fluid through the interior of
the conduit. Furthermore, after startup of the flow of fluids in
the conduit, the introduction of gas (nitrogen) is discontinued
into the conduit. As gas and oil (hydrocarbons) escape from the
wellhead, the oil and gas travel up the conduit 112. The liquid
(e.g., oil and seawater) is pumped out of the conduit to a storage
area, such as a tanker through the liquid ejection tube 130.
Furthermore, the natural gas contained in the containment tank 120
may be released through the gas release tube 124 where the natural
gas may be contained or flared. The liquid level 164 is maintained
below the seawater surface 22. The escaping oil and gas emitted
from the wellhead rise through the conduit where the liquid is
pumped out the liquid ejection tube 130 and gas is released through
the release tube respectively. The startup of the flow of fluids
through the conduit, as in the other dry embodiment discussed
above, provides for minimal flow of seawater and mostly
hydrocarbons, thereby reducing the formation of hydrates in the
interior of the conduit.
[0034] For both embodiments described above, as the conduit is
submerged, the induction bell enters the seawater open to the
seawater. Once the induction bell 134 is at the desired depth of
8000 feet or less, nitrogen is injected through the port 202 into
the interior of the induction bell to displace the seawater out of
the interior of the induction bell. For depths greater than 8000
feet, helium may be substituted for nitrogen. In addition, MEG,
methanol, or other chemical may be optionally injected into the
cavity 214 through the port 216 and discharged through the
discharge slot 220. The use of MEG, methanol, or other chemical
also reduces the occurrence of hydrates in the induction bell.
[0035] FIGS. 4A and 4B are flow charts illustrating the steps of
containing and capturing oil and gas from a leaking structure by
submerging a closed conduit according to the teachings of the
present invention. FIGS. 4A and 4B relate to the dry embodiment
discussed above. With reference to FIGS. 1-4, the method will now
be explained. The conduit may be constructed in sections to provide
a length allowing the conduit to span from the bottom of the ocean
floor where the wellhead is located to at or near the seawater
surface 22. Prior to beginning the method, the conduit is
assembled, preferably one section at a time and placed underwater.
The method begins with step 300, where the valves 190 and 192 are
closed to the conduit 112 or a section of the conduit.
[0036] Next, in step 302, the conduit or section of conduit is
submerged into the seawater to the desired depth or a maximum of
approximately 8000 feet. As the conduit descends into the seawater,
suitable gas such as nitrogen is introduced into the interior of
the conduit in step 304. The introduction of the suitable gas
provides an internal pressure to the conduit, thereby enhancing the
structural integrity of the conduit and preventing pressure from
the surrounding seawater from crushing the conduit. In most cases
where the depth of the conduit is less than approximately 8000
feet, the use of nitrogen is acceptable. In particular, nitrogen
hydrates do not form for seawater pressure of approximately 8000
feet or less. The conduit may still be lowered below 8000 feet
seawater pressure with the internal pressure of the conduit
remaining at approximately 8000 feet, which is of a sufficient
outward pressure upon the conduit to retain the structural
integrity of the conduit and counteract the inward pressure from
the seawater on the conduit. If the conduit is constructed in
sections, each section may include upper and lower valves to
prevent passage of seawater into the section's interior.
Additionally, each section may include a port to introduce the gas
(e.g., nitrogen) into the interior of the section. The sections are
added to the conduit as needed to provide a length of the conduit
as necessary for the required depth to the plume.
[0037] As the conduit is submerged, the induction bell enters the
seawater open to the seawater. In step 306, once the induction bell
134 is at the desired depth 8000 feet or less, nitrogen is
optionally injected through the port 202 into the interior of the
induction bell to displace the seawater out of the interior of the
induction bell. For depths greater than 8000 feet, helium (which
does not form hydrates below 8000 feet) may be substituted for
nitrogen. In addition, MEG, methanol, or other chemical may be
optionally injected into the cavity 214 through the port 216 and
discharged through the discharge slot 220. The use of MEG, methanol
or other chemical also reduces the occurrence of hydrates in the
induction bell.
[0038] In step 308, the conduit is positioned over the plume 50
from a leaking wellhead, man-made structure, BOP 40 or where the
leak emanates (e.g., seafloor). Next, in step 310, the appropriate
valves are then opened as necessary to meter a portion of the
leaking hydrocarbons (fluids, which includes gas and liquid) and
some seawater through the interior of the conduit. As the upward
flow of the fluids progress, the valves may be configured as
necessary to allow passage of a majority or all of the leaking
hydrocarbons through the interior of the conduit. Furthermore,
after startup of the flow of fluids in the conduit, the
introduction of gas (such as nitrogen) may be discontinued into the
conduit. As gas and oil (hydrocarbons) escape from the wellhead,
the oil and gas travel up the conduit 112. In step 312, the liquid
is pumped out of the conduit to a storage area, such as a tanker
through the liquid ejection tube 130. In step 314, the natural gas
contained in the containment tank 120 may be released through the
gas release tube 124 where the natural gas may be contained or
flared. The startup of the flow of fluids through the conduit
provides for minimal flow of seawater and mostly hydrocarbons,
thereby reducing the formation of hydrates in the interior of the
conduit.
[0039] FIGS. 5A and 5B are flow charts illustrating the steps of
containing and capturing oil and gas from a leaking structure by
submerging an open conduit according to the teachings of the
present invention. FIGS. 5A and 5B relate to the wet embodiment
discussed above. With reference to FIGS. 1-3, and 5, the method
will now be explained. The method begins with step 400 where the
lower valve 190 is opened. Next, in step 402, the conduit or
section of conduit is submerged into the seawater to the desired
depth or a maximum of approximately 8000 feet. In step 404,
nitrogen is then injected into the interior of the conduit through
port 200 to displace the seawater from the interior of the conduit.
The nitrogen gas displaces the seawater in the interior of the
conduit out through the valve 190. Valve 190 is then closed. If the
leaking structure is at a depth greater than approximately 8000
feet, the conduit may continue to be lowered to the desired depth.
As the conduit is submerged, the induction bell enters the seawater
open to the seawater. In step 406, once the induction bell 134 is
at the desired depth 8000 feet or less, nitrogen is optionally
injected through the part 202 into the interior of the induction
bell to displace the seawater out of the interior of the induction
bell. For depths greater than approximately 8000 feet, helium
(which does not form hydrates below 8000 feet) may be substituted
for nitrogen. In addition, MEG, methanol, other chemical or other
gas/liquid may be optionally injected into the cavity 214 through
the port 216 and discharged through the discharge slot 220. The use
of MEG, methanol, or other chemical also reduces the occurrence of
hydrates in the induction bell.
[0040] In step 408, the conduit is positioned over the plume 50
from a leaking wellhead, man-made structure, BOP 40 or where the
leak emanates (e.g., seafloor). Next, in step 410, the appropriate
valves are then opened as necessary to meter a portion of the
leaking hydrocarbons (i.e., fluids, which includes gas and liquid)
through the interior of the conduit. As the upward flow of the
fluids progress, the valves may be configured as necessary to allow
passage of a majority or all of the leaking hydrocarbons through
the interior of the conduit. Furthermore, after startup of the flow
of fluids in the conduit, the introduction of gas (nitrogen) may be
discontinued into the conduit. As gas and oil (hydrocarbons) escape
from the wellhead, the oil and gas travel up the conduit 112. In
step 412, the liquid is pumped out of the conduit to a storage
area, such as a tanker through the liquid ejection tube 130. In
step 414, the natural gas contained in the containment tank 120 is
released through the gas release tube 124 where the natural gas may
be contained or flared. The startup of the flow of fluids through
the conduit provides for minimal flow of seawater and mostly
hydrocarbons, thereby reducing the formation of hydrates in the
interior of the conduit.
[0041] The present invention utilizes a negative pressure
differential which causes the fluid to flow upward away from the
leaking structure. The oil and gas may be drawn from the interior
of the conduit and stored in areas designated by the operators. The
present invention introduces a suitable gas into the interior of
the conduit to eliminate or displace seawater from the interior of
the conduit during startup. Additionally, the introduction of a
suitable gas into the interior of the conduit provides an internal
pressure to counteract the external pressure from the surrounding
seawater.
[0042] While the present invention is described herein with
reference to illustrative embodiments for particular applications,
it should be understood that the invention is not limited thereto.
Those having ordinary skill in the art and access to the teachings
provided herein will recognize additional modifications,
applications, and embodiments within the scope thereof and
additional fields in which the present invention would be of
significant utility.
[0043] Thus, the present invention has been described herein with
reference to a particular embodiment for a particular application.
Those having ordinary skill in the art and access to the present
teachings will recognize additional modifications, applications and
embodiments within the scope thereof.
[0044] It is therefore intended by the appended claims to cover any
and all such applications, modifications and embodiments within the
scope of the present invention.
* * * * *