Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
CA 02799947 2012-12-27
Oil Spill Recovery System and Method
FIELD
The invention is in the field of oil spill cleanup, particularly oil spill
cleanup and recovery by
hydraulic separation.
BACKGROUND
Marine drilling for oil has expanded exponentially in recent decades, due to
the technologically-
facilitated accessibility to undersea reserves. However, with such drilling
comes the risk of oil
spills such as the Exxon Valdez incident that was a surface spill from a
tanker, and the BP
Deepwater Horizon spill, which occurred both at the surface and deep under the
sea.
Oil spills cause mass amounts of environmental damage and it is extremely time
consuming,
expensive and generally difficult to clean up the mess left in their wake.
Often oil spills occur in
hostile environments such as the sea subject to storms or in the far north.
Prior art oil spill
technologies include adding dispersants to disperse the spill, containing the
spill and burning
the oil. In these cases, the oil is lost or destroyed, which results in a
significant loss in addition
to the cleanup costs.
In the past, to address oil spills authorities have sucked the oil and water
mixture directly into
trucks or barges, wherein the mixture contained 95% water and 5% oil, and
either destroyed
the mixture reclaimed or separated the oil from the water offsite. This is
very inefficient due to
the high transportation costs. Further, barging and booming was commonly
practiced by
authorities; however the booms and the barges couldn't protect the coastline
because oil spill
constantly went overboard due to heavy blowing wind. As oil has monetary
value, a recovery
method is preferable to destruction of the oil that also leaves potentially
toxic by-products in
the environment.
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The cleanup procedure becomes even more challenging when a supervisor has to
be present at
the spill site for the duration of the process. Further, some of the most
skilled cleanup
specialists are only available remotely.
There is therefore a need for an oil cleanup system which vacuums up the
mixture of spilled oil
and water, and separates the oil from the water for processing and resale,
before returning the
clean water to the sea. Further there is a need for such a system that may be
operated
remotely.
More and more, fixed oil platforms are being replaced by mobile oil platforms,
connected to a
subsea well by a flexible hose, which enables the platform to move with the
water without
becoming disconnected to the well. There are risks that the hose break or
become
disconnected underwater and leak oil into the sea. Prior art means of finding
the hose break
are limited to checking along the high structure over the well. The hose flow
could be stopped
at various checkpoints along the hose length, as well, so that parts of the
hose could be
replaced without the requirement of replacing the whole hose, however finding
the broken
hose end was still a problem.
Therefore, there is also a need for a means of retrieving a broken subsea
hoses in order to
minimize the spilling of oil into the sea.
SUMMARY
An oil spill cleanup system is disclosed comprising a vessel; a separator
within the vessel for
separating oil and water, the separator further comprising two or more
adjacent tanks, having
first and last tanks, the tanks in overflowing communication; and a water
evacuation valve on a
lower portion of the first tank with a filter between the valve and the first
tank; a pump for
creating a vacuum and pumping an oil/water mixture into the separator; and one
or more
floating probes having hoses connected to the pump, for collecting the
oil/water mixture
wherein the pumps pumps the oil/water mixture into the top of the separator,
the oil/water
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mixture separates within the separator such that the oil floats on the water,
and the surface oil
overflows into the adjacent tank, and the water is evacuated from the water
evacuation valve.
An embodiment further comprises one or more submersibles connected by a hose
to the
pump, for collecting the oil/water mixture. The probes may be remotely
controlled and
manoeuvrable to the oil/water mixture, and each probe has a camera to identify
areas of high
oil concentration. The system may have an oil evacuation valve on the last
tank. The vessel may
be a ship or a truck.
A method for oil spill cleanup comprising: deploying one or more probes into
the oil spill for
sucking an oil/water mixture; sucking the oil/water mixture into a separator;
gravity separating
the oil/water mixture into oil and water; and evacuating the separated water.
The method may
further comprise the step of deploying a submersible into a subsea oil spill
for sucking the
oil/water mixture, or may further comprise the step of controlling the one or
more probes
remotely, using a camera. The method also may further comprise the step of
controlling the
one or more submersibles remotely, using a camera. In an embodiment, the
separator may
comprise two or more tanker trucks.
A mobile oil platform is disclosed, comprising: a vessel for holding oil; a
subsea hose connected
to a subsea well; a pump mounted on the vessel for detachably connecting to
the subsea hose
and for pumping oil into the vessel; one or more floats connected to the
subsea hose by cables
for holding the end of the subsea hose, wherein the subsea hose is detachably
connected to the
vessel and when full, the vessel detaches the hose such that the floats hold
the hose in the sea,
and the full vessel is replaced by an empty vessel.
A method of hose management for the mobile platform is disclosed comprising:
retrieving one
or more floats connected to a subsea well hose by cables; pulling the cables
from the sea to
retrieve the connected hose; and connecting the hose to a platform. The method
may further
comprise: detaching the hose from the platform; attaching the cables connected
to the one or
more floats to the hose; and dropping the hose in the water wherein the floats
mark a hose
position. In an embodiment, the floats are gas bags.
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The method may further comprise: deploying one or more probes into an oil
spill for sucking
an oil/water mixture; sucking the oil/water mixture into a separator; gravity
separating the
oil/water mixture into oil and water; and evacuating the separated water. In
an embodiment,
the method further comprises the step of deploying a submersible into a subsea
oil spill for
sucking the oil/water mixture. It may also further comprise the step of
controlling the one or
more probes remotely, using a camera, or controlling the one or more
submersibles remotely,
using a camera.
DESCRIPTION OF FIGURES
Figure 1 shows the oil spill recovery system, according to one embodiment of
the present
invention;
Figure 2 shows a perspective view of the oil spill recovery system, according
to one
embodiment of the present invention;
Figure 3 shows the technician within a remote cleanup control centre,
according to one
embodiment of the present invention;
Figure 4 shows a plan view of a surface probe, according to one embodiment of
the present
invention;
Figure 5 shows an elevation view of a surface probe, according to one
embodiment of the
present invention;
Figure 6 shows a cut away view of the separator ship, according to one
embodiment of the
present invention;
Figure 7a shows a cut away view of the separator, according to one embodiment
of the present
invention;
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Figure 7b shows a cut away view of the separator, according to another
embodiment of the
present invention;
Figure 8 shows the pump mounted on the separator, according to one embodiment
of the
present invention;
Figure 9a shows an elevation view of the separator, according to one
embodiment of the
present invention;
Figure 9b shows a plan view of the separator, according to one embodiment of
the present
invention;
Figure 10a shows a perspective view of the dual truck separator, according to
one embodiment
of the present invention;
Figure 10b shows a perspective view of a single truck separator, according to
one embodiment
of the present invention;
Figure 11 shows a plan view of a platform connected to a subsea well;
Figure 12 shows a plan view of floats attached to the subsea well hose;
Figure 13 shows a plan view of the platform and relief vessels above the
subsea well; and
Figure 14 shows plan view of the platform and relief vessels above the subsea
well, cleaning up
an oil spill.
DETAILED DESCRIPTION
The word "vessel" includes in its meaning oil tanker ships and converted
separator ships, oil
carrier trucks, separator trucks or oil carrier trucks carried on a ship.
The words "sea" and "subsea" refer to any body of water, including oceans,
seas, lakes and
inland waterways.
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The described oil spill cleanup system provides an efficient way to clean up
an oil spill that can
be operated remotely from within a control room on a ship or on a truck, for
example.
Depending on the scale required, the ship may be as large as an oil tanker or
much smaller,
with lower operating costs and greater agility. With reference to Figures 1
and 2 the separator
ship 10 is shown floating within an oil spill 8. The ship 10 has a submarine
hose 12 having a
coupler 14 for connection to a remote-controlled submersible 15. The coupler
facilitates use of
different length or thickness of hoses. The submersible 15 has no passengers,
therefore need
not be pressurized, and is thus capable of descending beyond 10000m, able to
probe the
deepest regions of the sea. Assuming an undersea spill, the submersible is
directed to the
source of the spill and vacuums the spill up through the hose 12. The hose 12
is a durable oil-
resistant hose that may be reeled out to the depth desired, beyond 10000m in
some cases. A
pump 20 on the ship 10 pulls the oily water from the hose 12 and into the ship
10. The
submersible 15 directs the hose 12 to the spill, and pumping water from the
spill into the ship is
performed by the pump 20 on the ship. The submersible 15 may be robotic in
that, once the
location of the undersea spill is provided, it is able to direct itself to the
spill without user
intervention. As will be seen below, within the ship is a mechanism to
separate the oil and
water. The resulting oil-free water is returned to the sea by a nozzle 24.
Further, at least one surface probe 25 is deployed within the spill waters
surrounding the ship
10. The probe 25 is remote controlled such that it may be steered to areas of
greatest oil
density. The control may be from any remote location, however preferably
located in the ship
bridge 27. As shown in Figure 3, the cleanup technician, in front of his deck,
has live videos of
the oil spill area from the probe and from the ship; therefore, the cleanup
operating room may
be anywhere in the world. The surface hose 30 is connected to the probe 25 by
means of a hose
connector, which facilitates changing the hose for longer or shorter, or
different hose
characteristics. The probe 25 is then connected to the pump 20 by the hose 30.
The probe
directs the hose 30 to a desired location, and the pump 20 then sucks the oil/
water mixture
into the ship 10 for separation.
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CA 02799947 2012-12-27
The probe 25 may simply comprise a float that floats around the spill waters
and sucks up the
oil/water mixture on the surface. In an embodiment, the surface hose 30 may be
directed by
personnel in a small motorboat or other vehicle. There may be a plurality of
surface hoses,
fanning out around the ship 10 in order to cover a broader area.
With reference to Figures 4 and 5, an embodiment of the surface probe 25 is
shown. The probe
25 is operable on either side, therefore is able to withstand rough seas which
may flip it over.
The probe body 28 floats as it is filled with foam or gas, or having sealed
floats therein. The
float has a hose connector 26 for the hose 30. At the end opposite the hose
connector 26, is a
sucking tube 40 for sucking the oil/water surface mixture. In one embodiment,
the sucking tube
40 is movable and manoeuvrable into the oil nearby, as seen in Figure 4.
Further, the sucking
tube 40 may have a camera 42 for identifying the locations of greater oil
concentration for
increased efficiency. For mobility, the probe has paddles or a rudder and
propeller
configuration, as is known in the art.
The probe 25 may be operated remotely, and the camera 42 sends real-time
footage of the
area and of oil concentrations to the operator who may operate the probe 25 as
easily as if
onsite. The probe may also be robotic in that it senses the location of the
oil and directs itself
there to suck up the oil/water mixture.
With reference to Figure 6 the vacuum pump 20 generates a vacuum and can suck
up oil and
deposit it directly into the ship's first and second tanks 32, 34. The tanks
are open to one
another at the top, and are separated by a high wall 31 between them, which
wall 31 extends
80 ¨ 95% of the height of the tanks 32, 34. With reference to Figure 6, the
tanks may be
organized adjacent lengthwise of the ship, such that one tank is on the port
side of the ship and
one on the starboard side, or adjacent widthwise of the ship, such that the
first tank is in the
bow of the ship and the second tank in the stern. In order to prevent listing
of the vessel the
tanks 32, 34 may take concentric forms, for example, to prevent the oil/water
mixture from
weighing only one side of the vessel and risk capsizing. Multiple tanks may
also be used within
the ship in a separator, for further, better separation of oil and water, as
discussed below.
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CA 02799947 2012-12-27
The oil/water mixture is pumped from the submersible 15 or the probe 25,
through the hoses
12, 30 and into the first tank deck 32. The oil and water can be separated by
specific gravity
("gravity separation") as oil is less dense than water and hydrophobic, so the
water is pushed to
the bottom of the first tank deck and the separation between the oil 35 and
water 37 is quite
distinct. The first tank deck is filled with the oil/water mixture, which
separates as it is filled.
With the oil on top, once the level of the first tank overflows into the
second, it is only oil that is
transferred since the water remains in the bottom of the first tank 32. Any
excess volume in the
first tank overflows into the second tank deck 34. The clean water at the
bottom of the first
tank deck 32 will dispense back into the body of water through the nozzle 24,
by means of a
pump (not shown) or simply by water pressure.
A separator 50 is shown in Figures 7a - 7b, 8 and 9a 9b, which may be present
in the ship 10
(not shown) or a truck (not shown), having a pump 20 above the separator 50 to
pull the
oil/water mixture in. The separator 50 consists of a number of tanks, in one
embodiment four
tanks 32, 34, 52, 54. The first tank 32 receives the water/oil mixture from
the pump 20, through
an entry 55 located above the first tank 32. As the first tanks fills, the oil
separates to the top of
the tank, and the water separates to the bottom. When full, the tank will have
gradients, with
almost pure oil at the top, with a mixture of water and oil in the middle, and
almost pure water
at the bottom. As the mixture settles the gradients are more defined. A
typical breakdown in
the first tank 32 is 15% pure oil, 35% water/oil mixture, and 50% water. Once
full, the first tank
32 overflows, such that the almost pure oil at the top overflows into the
second tank 34. The
second tank is now 50% oil, and 50% water/oil mixture. As the second tank
fills and the oil rises
to the top, it overflows into the third tank 52, such that the third tank is
90% oil. The third tank
overflows once full, and given that the components have had a chance to
settle, the overflow is
pure oil and therefore the fourth tank 54 contains 100% pure oil, which may be
evacuated
through the oil evacuation valve 57, which has a pump (not shown) to
facilitate evacuation. The
clean water that settles to the bottom of the first tank 32 is evacuated by
the water evacuation
valve 59 on a lower portion of the first tank 32. There is a mechanical filter
53 between the
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valve 59 and the tanks 32. In one embodiment the filter extends to the top of
the separator 50,
and creates an oil free zone 49.
Such a separator may be within the ship or within a truck, for mobile
shoreline applications. It
may also be operated and monitored remotely. In Figures 9a - b and 10a - b, a
configuration
preferable to a truck is shown, wherein the separator 50 is contained within a
truck body 51
and may be entered by a door 60, and the various tanks accessed by steps 65.
The separator 50
operates as described above and the water is ejected from the truck once
separated.
With reference to Figures 10a - b, tanker trucks 66 can be used as vessels to
remove oil from
the shoreline. The trucks 66 are designed to contain a separator 50, which
receives an oil/water
mixture from a plurality of hoses 72 connected to a pump 71 mounted to the
roof of the truck
66. The hoses 72 are inserted into the oil/water mixture, and the pump 71
sucks the mixture
into the first tank of the separator (not shown).
Two trucks may implement the two-tank design described above, wherein a first
tank 62 is
within a first truck 66 and a second tank 64 is within a second truck 67. The
oil/water mixture
70 is pumped into the first tank 62 within the first truck 66 by oil spill
hoses 72, from a probe 25
or simply vacuuming the shore oil by hand or boat, and a transfer 68 hose at
the top of the first
truck 66 sucks the separated oil from the top of the first tank 62 and into
the second tank 64
where it further separates. Separated water is ejected from the bottom 62a of
each tank (not
shown for second tank), and after a period of time the second tank 64 will be
full of separated
oil, at which point it may be hauled away in the second truck 67, and a
further truck (not
shown) with the same features replaces it The chain of trucks, with a further
truck replacing a
full second truck, will continue until the cleanup is complete.
With reference to Figure 11, a further oil spill safety system comprised of
floats for facilitating
the retrieval of an undersea hose from a subsea well 105. The subsea well 105
is typically
connected to a mobile oil platform 100 with a hose 110 to pump the oil up and
into the
platform by means of a pump 102. The platform 100 may consist of an oil
carrier vessel
converted for the purpose of pumping up and storing the oil from the subsea
well. The
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converted oil carrier vessel as platform 100 can drop the hose 110 and depart
once full, taking
the oil to port, while a replacement oil carrier arrives to serve as platform
100 for the hose 110.
The hose opening 112 closes while the hose 110 is not attached to the platform
100 so as to
prevent the spilling of oil. Detachment of the hose 110 from the platform 100
is also beneficial
in case of an emergency, when the crew and costly equipment can be relocated,
rather than
remain in place as a fixed oil platform must.
The platform 100 is equipped with a winch. The hose attachment method is as
follows: i) once
the platform arrives at the well, and retrieve the floats 115 holding the hose
110, the
technicians free the cable 113 from the floats 115, which are hooked to the
exterior of the
vessel for storage; ii) the cable 113 is hooked to the winch, and iii) the
hose 110 emerges from
the sea, and iv) the hose opening 112 is connected to the platform 100. For
detachment, the
hose opening 112 is detached from the platform 110; ii) the cable 113 is
attached to the hose
110 and the hose 110 lowered into the water by the winch; Hi) the floats 115
are reattached to
the cable 113; and iv) the floats float in the water holding the hose 110 at a
known position.
The benefits of eliminating fixed oil platforms in favour of the described
converted oil carrier
vessels is the safety benefit of having a platform that is movable from the
danger zone; the
mobile platform of the converted oil carrier is cheaper and easier to
manufacture and deploy;
and the fixed structure that is susceptible to water movement and storms is
replaced by a long
hose that is flexible and allows the platform to move with the elements.
With reference to Figure 12, floats 115 hold the hose 100 in an accessible
position for the
arrival of the next platform 100, and prevent it from sinking. The hose may be
connected to the
one or more floats by cable 113 or other similar means. The floats 115 contain
a substance
having a lower density than water, and may consist of robust balloons or gas
bags for holding a
gas, for example, or foam. Balloons or gas bags have the advantage of
portability when not in
use, however foam floats do not require inflation or deflation. Multiple
floats have the benefit
of maintaining floatation despite the failure of one or more of the floats.
The floats may have
CA 02799947 2012-12-27
surveillance cameras attached thereto to ensure the security of the subsea
well, and to monitor
shipping lanes as desired.
With reference to Figure 13, the system is shown, with the platform 100
pumping oil through
the hose 110 from the subsea well 105, the hose 110 attached to the platform's
pump 102,
which pumps the oil. The floats 115 are attached to the hose 110 to facilitate
disconnection and
connection to another platform 100 in the form of a vessel. In this
embodiment, platform 100 is
an oil carrier vessel, which can detach the hose 110 and depart when full, to
be replaced by
another empty oil carrier vessel (not shown). In an embodiment, two further
relief vessels 120
are present for receiving oil from the platform 100 via oil transfer hoses
122, to prevent the
platform 100 from becoming full and dropping the hose 110.
With reference to Figure 14, the floats 115 are shown on the hose 110 in case
the hose 110 is
dropped by the platform 100. Further, an oil spill surrounds the platform 100
and the probe 25
is deployed into the oily water as described above to vacuum the oily water
into the platform
100 using the pump 121, to which both hoses 12, 30 are attached. In one
embodiment,
platform 100 is an oil carrier vessel also containing a separator 50 for the
spilled oil, which
evacuates clean water from the water evacuation valve 123. For example, 80% of
the storage
capacity may be used for oil storage while 20% of the storage capacity is used
for the separator
50. Therefore, the vessel may serve three purposes, as an oil carrier for use
as a platform, as a
separator for oil spill cleanup, and as an oil carrier/separator for use as a
platform with
availability for cleanup should the need arise. Further, a submersible 15 is
deployed to clean up
an underwater spill 8. A helicopter 125 is available for support functions and
evacuation.
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