Patent Application
20140023439
The present invention relates to oil leaks under water (or similar situations such as gas leaks on land) and means of containing and recovering spilled oil, quickly, efficiently and conveniently thereby minimizing loss of oil and protecting the environment.
For years, the problem of salvaging deep sea oil leaks has been of great concern. It has long been known that such leaks waste valuable quantities of oil and/or gas, and the oil causes huge environmental problems, both to the sea, beaches, wildlife, etc. The monetary expense and cost to the environment of these spills is staggering.
Great quantities of oil wastage are involved with these spills. For example, in the 1979 tragedy of the Mexican oil well leak in the Bay of Campeche, it was reported that the leak was spewing out more than 10,000 barrels of oil daily, and that in less than three months it had dumped over 2,000,000 barrels of oil into the gulf.
The recent Deepwater Horizon oil spill spilled oil in the Gulf of Mexico for three months in 2010. The impact of the spill continued long after the well was capped. It is the largest accidental marine oil spill in the history of the petroleum industry. On July 15, the leak was stopped by capping the gushing wellhead, but not until after it had released about 4.9 million barrels or 205.8 million gallons of crude oil. It was estimated that 53,000 barrels per day (8,400 m3/d) were escaping from the well just before it was capped. It is believed that the daily flow rate diminished over time, starting at about 62,000 barrels per day (9,900 m3/d) and decreasing as the reservoir of hydrocarbons feeding the gusher was gradually depleted. On September 19, the relief well process was successfully completed, and the federal government declared the well “effectively dead”. However, the spill continues to cause extensive damage to marine and wildlife habitats as well as the Gulf's fishing and tourism industries.
In late November 2010, 4,200 square miles (11,000 km2) of the Gulf were re-closed to shrimping after tar balls were found in shrimpers' nets. The total amount of Louisiana shoreline impacted by oil grew from 287 in July to 320 miles (510 km) in late November. In January 2011, eight months after the explosion, an oil spill commissioner reported that tar balls continue to wash up, oil sheen trails are seen in the wake of fishing boats, wetlands marsh grass remains fouled and dying, and that crude oil lies offshore in deep water and in fine silts and sands onshore.
Accordingly, there remains a need to provide a means of containing and recovering spilled oil, quickly, efficiently and conveniently, thereby minimizing loss of oil and protecting the environment.
The present invention generally relates to containment and control of an oil spill caused by a damaged or broken riser in deepwater, damaged subsea equipment, or the like. It can also be used for preventative purposes, such as during the drilling cycle.
More specifically, the present invention relates to a reusable unit that will contain oil spills to a specific location and also allow oil to be harvested as it flows to the top of the unit while minimizing or even eliminating any environmental clean-up cost.
An object of the present invention is to provide a containment unit comprising a weighted base, at least one flotation unit and a barrier.
The unit of the present invention is dropped over a damaged or broken riser or damaged equipment. The unit is released and stabilized in sections until the surface of the water is reached and the containment unit is completely erected. Alternatively, the sections could be extended to any distance above the mud line, not necessarily to the surface of the water.
It is another object of the present invention to provide a method of using a containment unit, comprising the steps of: a) deploying a compressed containment unit to the ocean floor over a broken riser; b) releasing a first flotation unit; c) releasing subsequent flotation units sequentially at regular increments, preferably 1,000 foot increments, until the ocean surface is reached; and d) anchoring each flotation unit as necessary before releasing a subsequent flotation unit.
There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described further hereinafter.
In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting.
As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may be readily utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that equivalent constructions insofar as they do not depart from the spirit and scope of the present invention, are included in the present invention.
For a better understanding of the invention, its operating advantages and the aims attained by its uses, references should be had to the accompanying drawings and descriptive matter which illustrate preferred embodiments of the invention.
Preferred embodiments of the invention will be set forth in detail with reference to the drawings, in which like reference numerals refer to like elements throughout.
The containment unit of the first preferred embodiment is used by having a Remotely Operated Vehicle (ROV) deploy a compressed containment unit to the ocean floor over a broken riser. A first flotation unit is released, and subsequent flotation units are then sequentially released at about 1,000 foot increments until the ocean surface is reached. Each flotation unit is anchored to the ocean floor (preferably up to 3,000 feet from the ocean floor) or to tug boats/barges (preferably over 3,000 feet from the ocean floor) as necessary to stabilize each flotation unit before releasing a subsequent flotation unit.
The result is an erected containment unit comprising multiple flotation units (depending on the depth needed) with Kevlar or rubber walls reinforced with cables, rubber coated cables or solid PVC piping, which keeps the spilled oil in one specific location and does not allow the oil to spread and contaminate the environment. The containment unit of the present invention also allows ships or tankers to draw the oil from the top of the unit.
The process will now be described in greater detail. The specifics of the process are illustrative rather than limiting and can vary as determined by specific needs or conditions.
As shown in
As shown in
The containment unit is preferably made of barrier walls comprising a synthetic fiber, preferably an aramid fiber material such as Kevlar or Twaron, reinforced with cable, with flotation units at about 1,000 foot increments to form a stack or tower. Both the dimensions and the material are illustrative rather than limiting and can be determined by circumstances. Alternatively, the walls may be made of rubber. The flotation units are preferably braced with metal bars. The unit is preferably large enough to allow equipment to be deployed from the surface of the unit. More preferably, it can be used as a drafting tank, while protecting the environment.
The containment unit of the first embodiment is preferably made up of 4 flotation units and 1 anchor unit. Each flotation unit preferably has an inside diameter of 30×30 feet to accommodate a broken/damaged riser and Kevlar walls reinforced with rubber coated iron cables for frame support. The base unit is 2 to 4 tons and 20 feet high depending on the water depth. The containment unit may also be square, rectangle, oval or round.
The walls are preferably made of a layer of Kevlar with a rubber coated cable frame and then another coat of Kevlar for added strength. When attached to the flotation units that will become the containment unit, the cables comprise 20,000 feet of Kevlar and cable frame. Each flotation unit will rise 1,000 feet. While Kevlar is given as an illustrative example, any other suitable material can be used, as long as it is impermeable to oil, flexible, and not broken down by oil or salt water. Kevlar is considered a good choice because it can withstand salt water for long-term deployments.
The base unit serves as a platform and housing for the flotation units. All flotation units are stacked on top of the base unit and lowered to the ocean floor. Packing straps are released from the base unit to the top flotation unit, one at a time. Each section must be stabilized before moving to the next section at 1,000 foot increments. Preferably, all units are not released at once to avoid ripping of material and loss of control of the stacking process. The containment unit should be raised as straight as possible, but the pliable materials (Kevlar/cables) allow it to shift and sway with the movement of the ocean. Alternatively, the base unit could be made of clump weights and preinstalled.
An ROV is utilized to release each flotation unit starting from base unit. Drop anchor blocks with attached cables at strategic points are used for structural support. As the first flotation unit is released, it will rise up 1,000 feet from the base, with or without the additional use of lift bags or air bags. The first flotation unit may or may not need anchor lines for support. If so, anchors are attached before the second flotation unit is released. Then the second unit is released and the containment unit is raised another 1,000 feet, i.e., 2,000 feet total, and anchor blocks are attached with cables to the flotation unit. ROVs are used to anchor all 4 sides every 1,000 feet. Then the ROV releases the third flotation unit and anchors it at 3,000 feet on 4 sides. This method is used up to 3,000 feet. Barges or tug boats are used once the containment unit is 4,000 to 5,000 feet high.
At approximately 4,000 feet, anchor lines may be attached to barges or tug boats for additional support and stabilization of the units. At the surface of ocean, additional flotation units can be added to increase the height of the containment unit. An additional perimeter barrier such as an oil boom can be used around the surface containment section to capture any oil that may escape from the containment unit. As the riser loses pressure and oil flows to the surface, ships can draw oil from the surface inside the containment area.
The completed structure is high enough to contain the oil while necessary repairs are done without allowing oil to reach the shoreline. On that note, the unit is a “containment” unit and not a “tank”; i.e., sea water will flow into the unit through an opening in the concrete base, and the oil, via pressure, will push upwards to the surface for capture by barges/ships on the surface. Sea water is necessary in order to avoid freezing of the oil at such depths.
Preferably, the containment unit of the present invention is compressed for storage, such as by means of straps, preferably rubber or nylon straps. The packaging for deployment can include pulleys and other devices to prevent tangling of the cables. The cables themselves can be made out of metal, nylon, or any other material capable of withstanding the environment.
The second preferred embodiment is constructed and used like the first preferred embodiment, with the flotation unit lowered in the closed position over the riser or other equipment and the anchor unit, and opened up from the bottom to the top. The second preferred embodiment uses a storm cap and buoy to contain oil (or gas, etc.) in a Kevlar (or other suitable material) column to direct flow to a production vessel/tanker. More specifically, as shown in
The storm cap 910 is a transfer tank that retains oil while allowing gas to escape. The containment unit 900 can be topped initially with a metal plate, which is then replaced with the storm cap 910 as necessary.
One advantage of the present invention over conventional techniques is that only three ships are required: a transfer ship 914, which separates oil from water; a tanker 920, which carries the oil to shore, and a deployment ship 922, which deploys the unit 900. The containment unit 900 can be conveyed in a closed position by the deployment ship 920 and then opened and installed from bottom to top. Another is that the storm cap 910 can be used at various locations depending on local conditions, including storms. For example, the storm cap 910 can be located at the least pressure point. The gap between the storm cap 910 and the water's surface 916, in combination with the use of the hose 912, will protect ships from explosions.
The second preferred embodiment provides for the containment and control of an oil spill caused by a damaged or faulty piece of subsea equipment in deepwater situations. The containment unit of the present invention is a cost effective way to contain oil spills to a specific location and also allows the oil to be harvested as it flows to the top at the water surface, minimizing impact on the environment.
The unit 900 itself is comprised of two major components. The first is a weighted base 902 measuring approximately 30 feet in diameter, preferably circular. The unit can also have different shapes to best suit the need of a specific situation. The base is made of concrete and embedded structural beams. Its purpose is to provide an anchor for the rest of the components to function properly. The unit 900 is deployed over a leaking structure 1002, such as a blowout preventer (BOP), on or near the seabed 1004 as shown in
The second piece of the unit is a section of barrier composed of a flotation unit 908 at the top of an encompassing perimeter 906 made of Kevlar or other such material which extends down from the flotation unit 1,000 feet. The sections are connected topside before deployment. The number of sections needed depends on the water depth on location, one section per 1,000 feet water depth. There are numerous ways to install and customize the above components to facilitate installation in adverse conditions such as high currents and well pressure. A guide by wire system may be used to attach barrier components to the concrete base. Provisions can also be made to supply enough mooring points to the overall unit to withstand currents and vibrations. This can be done with clump weights, a partial ring or other available methods to obtain stability.
The Kevlar or other material provides an insulating column that acts as a barrier to keep the environment safe. The material is preferably light-weight to maintain stability during deployment and recovery. As seen in
The structure of the second embodiment provides:
In either of the preferred embodiments, or in any other embodiment, variations on the flotation device are possible. For example, lift bags can be used for quick erection, and the flotation units are then used to keep the containment unit upright and erected. Although foam is preferred for the flotation units because of its stability for long-term deployment in various environments, other suitable materials as would be known to one of skill in the art may also be used. Preferably, the foam should be able to provide sufficient lift, e.g., 1,000 lbs, to keep the containment unit upright. In addition to the flotation units that are permanently mounted to the inside of the barrier at 1,000 foot increments, additional flotation units may be added to the exterior of the barrier, i.e., flotation donuts. These flotation donuts may be fixed to the outside of the barrier or may be movable, i.e., they can be fixed to the exterior of the barrier during manufacture or during deployment. Also, the spacing can be varied; for example, the external (donut) flotation units can be placed every 500 or 800 feet as the conditions warrant. In addition, the weighted base can be replaced by, or supplemented with, an anchoring scheme in which pins are shot into the mud at the sea floor.
Having now described a few embodiments of the invention, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by way of example only. Numerous modifications and other embodiments are within the scope of the invention and any equivalent thereto. It can be appreciated that variations to the present invention would be readily apparent to those skilled in the art, and the present invention is intended to include those alternatives.
Further, since numerous modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention. For example, numerical limitations are illustrative rather than limiting, as are recitations of particular materials. Also, the invention can be used to contain any leak of a material into an ambient fluid, in which the ambient fluid can be water, air for land-based uses, or the like. Therefore, the present invention should be construed as limited only by the appended claims.
The present application is a continuation-in-part of U.S. Provisional Patent Application No. 61/439,352, filed Feb. 3, 2011, whose disclosure is hereby incorporated by reference in its entirety into the present disclosure.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2012/023839 | 2/3/2012 | WO | 00 | 10/9/2013 |
| Number | Date | Country | |
|---|---|---|---|
| 61439352 | Feb 2011 | US |
