1. Field of the Invention
Embodiments of the present invention relate generally to an apparatus for providing a column of water for collecting underwater fluids and contaminants. More particularly, embodiments of the present invention relate to a chimney-type apparatus that is used to collect fluids having a lower density than water, for example, oil from shipwrecks, sunken oil tankers, or underwater wells, or to collect large volumes of water, for example, cold seawater. Additionally, embodiments of the present invention relate to non vertical, large diameter underwater conduits that can be used to transport water and other fluids to the shore.
2. Description of the Related Art
Typically, the pumping and/or the recovery of a liquid product or viscous material, such as, for example, fuel or petroleum (oil), from the ocean floor at deep depths from a sunken oil tanker or from oil wells, is difficult if not impossible mainly because of depths ranging from 3000 to 4000 m and high hydrostatic pressures, for example, 400 bars. In addition, recovery efforts can be impeded by bad weather, which results in rough seas.
An example of a prior device for such recovery efforts includes International Application Publication No. WO 94/17251, which is directed to a device for collecting fluids from shipwrecks. The device described in this application, however, is limited by the depths at which it can be used.
Another example of a prior device includes French Patent No. 2 850 425, filed on Jan. 28, 2003 (the “French patent”), also published as International Application Publication No. WO 2004/070165 (the “International publication”), both of which are by the inventors named on the present application and which are directed to a device for recovering petroleum from a shipwreck. The entire contents of both the French patent and the International application are incorporated herein by reference in its entirety. The present application is directed to improvements on the French patent and the International application.
For the reasons included above, it is therefore a principal object of embodiments of the present invention to provide an apparatus for the collection or sub sea oil and seawater.
It is a further object of embodiments of the present invention to provide an apparatus that can deliver the large volumes of cold seawater required for Ocean Thermal Energy Conversion (“OTEC”), seawater-based air conditioning (“SWAC”), and other cooling processes such as, for example, natural gas liquefaction.
Yet another object of embodiments of the present invention is to provide an apparatus that can provide an isolated column of seawater from the depths of the oceans to the oceans' surface.
A further object of embodiments of the present invention is to provide a modular, tubular structure or chimney-type apparatus that can be constructed on-site to provide a column of seawater from the depths of the oceans to the oceans' surface.
A still further object of embodiments of the present invention is to provide a modular, fabric or textile, tubular apparatus that can be constructed on-site to provide a column of seawater in order to act as a passageway for oil, cold seawater, and nutrients or other products carried by air lifted water such as metallic nodules located at depth in the oceans to the oceans' surface.
A further object of embodiments of the present invention is to provide an apparatus that can be used to shelter piping, risers and other equipment used in offshore drilling operations and/or to insulate such equipment from the surrounding cold seawater.
Yet another object of embodiments of the present invention is to provide an apparatus that can be used to circulate warmer water from the ocean surface around piping, risers and other equipment used in offshore drilling operations in order to heat up oil that is recovered as a result of offshore drilling operations or that is recovered from sunken ships.
These and other objects and advantages are provided by the embodiments of the instant invention. In this regard, embodiments of the present invention are directed to a tubular apparatus having a large diameter. The apparatus provides a vertical column of water regardless of the depth in the ocean to the ocean's surface. Such an apparatus can be used in many applications, examples of which include:
Accordingly, in one embodiment, the present invention includes a base structure that is anchored to the ocean floor above the area of interest where, for example, oil is to be recovered or cold seawater is to be taken from. Attached to the base structure is a plurality of modular elements that are connected together by a plurality of connecting rings. The depth of the base structure determines the number of modular elements that need to be connected such that a continuous column of seawater extends from the base structure to the ocean surface. Attached to the topmost modular element is either a collecting means for collecting, for example, recovered oil, or a means for attaching the topmost modular element to an oil rig or an OTEC or SWAC platform where an OTEC, SWAC or other renewable energy plant may be located. Extending from the base structure through anchoring means on the ocean floor, through the connecting rings and onto a platform on the ocean surface, is a plurality of ropes or cables that connect to winches, capstans or hydraulic jacks. These ropes or cables are used to anchor the chimney apparatus to the ocean floor and to provide vertical tensioning in order to vertically stabilize the structure. In order to prevent oil from adhering to the interior surface of the base structure and the modular elements, the interior surfaces are coated with an anti-adhesive coating. Further, in one embodiment, the modular elements and the base structure can be a double walled structure having an interior wall and an exterior wall that provides a layer of water between the two in order to insulate the interior of the structure from the surrounding seawater.
According to another embodiment of the present invention, instead of using an anchoring means to anchor the structure and provide tension, the structure may be directly hung from a floating body or platform with tension being provided by the structure's own weight and a ballast means at its bottom end. Thus, the bottom end of the tubular structure will be allowed to hang freely in the body of water.
For a better understanding of the embodiments of the present invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying descriptive matter in which preferred embodiments of the invention are illustrated in the accompanying drawings.
Preferred features of the embodiments of the present invention are disclosed in the accompanying drawings, wherein similar reference characters denote similar elements throughout the several views, and wherein:
Embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these illustrated embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.
In the following description, like reference characters designate like or corresponding parts throughout the FIGS. Additionally, in the following description, it is understood that terms such as “top,” “bottom,” “upper,” “lower,” and the like, are words of convenience and are not to be construed as limiting terms.
Typically, oil or petroleum exploration by way of offshore oil rigs is performed using metal piping. The metal pipes are connected to each other using fittings such that a plurality of pipes can be connected together to form a continuous passageway from the well on the ocean floor to an oil rig at the surface for the extraction of the oil. However, because the joined metal pipes form a rigid structure, the pipes undergo numerous vibrations as a result of high currents or rough seas acting on the pipes. These high vibrations result in the pipes undergoing significant mechanical stresses, which may result in damage to the pipes, thereby allowing oil to leak from the pipes. In addition, at depths beneath the thermocline, the temperature of seawater is low. Lower temperatures result in the viscosity of oil at these depth being higher, which makes extraction and recovery of oil more difficult and problematic. Because of these issues associated with deep water drilling and extraction, oil exploration and recovery typically does not exceed a depth of 3,000 m, however, with embodiments of the present invention, deeper oil exploration and recovery is possible. For example, embodiments of the present invention (1) can be used to deliver warmer water from the surface down to the oil wells on the ocean floor or (2) can be used to provide an insulated structure to protect against the colder seawater.
Further, with offshore drilling, there is always the possibility of a blow-out or explosion at the well located on the ocean floor. Currently, there is no one standard device that can be used to recover leaking oil as a result of a blow-out or an explosion because the circumstances surrounding a blow-out or explosion are unique, i.e., the depth of the blow-out or explosion, the position and condition of the pipes extending from the well, etc. Moreover, with a blow out, a gas such as methane usually leaks from the well with the leaking oil. This is problematic because the high pressures and low temperatures that are present on the ocean floor, results in the methane gas crystallizing, which typically causes an obstruction or blockage in any apparatus that is used to recover the leaking oil.
In addition, oil recovery from sunken oil tankers is also difficult and problematic because the circumstances surrounding a sunken ship are also unique, i.e., the depth of the sunken ship, the position of the sunken ship, the number of leaks and the location of the leaking oil, the ocean conditions in the area of the sunken ship, etc.
Moreover, Ocean Thermal Energy Conversion (“OTEC”), which uses the temperature differences between the ocean's colder deep water and the warmer surface water as a renewable energy source to produce commercial power, and seawater-based air conditioning (“SWAC”), which uses cold seawater located near coastlines as an air conditioner coolant, both require large volumes of seawater. For OTEC, the volume of cold water that must be supplied from the oceans' depths is very large, on the order of 150 m3/s (for a 50 MW power plant) or 3 m3/s per MW (megawatt). Such a volume of seawater requires a pipe having a cross-sectional area of 150 m2, which equates to a pipe having a diameter of over 14 m (approximately 45 ft.). With current technology, it is difficult, if not impossible, to design and construct a metal pipe having such a diameter.
Thus, a need exists for an apparatus that can be used for (1) deep water oil recovery either as a result normal drilling operations or from a blow-out or explosion, (2) oil recovery from sunken oil tankers, and/or (3) that can be used to deliver the large volumes of cold water necessary for OTEC and SWAC. Additional applications for the embodiments of the present invention include, and are not limited to, bringing minerals located on the ocean floor or sea bed to the surface and use in fish farms or the like. Fish farms require nutrient-rich water. Thus, the present apparatus can be used to bring the deeper, nutrient-rich water, to the surface where the fish farms are located. Embodiments of the present invention are directed to addressing these needs and can be used in various bodies of water such as, for example, oceans, lakes, etc.
Embodiments of the present invention are directed to a modular flexible tubular apparatus/structure that can be deployed anywhere in the world's oceans or other bodies of water in order to recover oil or other fluids or to provide the large volumes of cold water necessary for OTEC and SWAC operations or any process that utilizes the temperature difference between a body of water's warmer surface water and its colder water at depth as a renewable energy source. The modular flexible tubular apparatus/structure can be constructed from, for example, fabric or textile membranes. Essentially, embodiments of the present invention provide a vertical column of water from a body of water's floor to its surface. This vertical column of water is shielded from the surrounding currents and water conditions and therefore, provides a column of calm water. This column of calm water can be used to provide shelter for other structures such as oil piping risers. Advantageously, because the tubular apparatus can be used to provide a vertical column of seawater, recovery of oil from deep within the oceans, can be performed without the need for pumping equipment. This is possible because oil is less dense than seawater and, as a result, is more buoyant than seawater. Consequently, oil that enters the tubular apparatus rises up the column of seawater to the surface as a result of its natural buoyancy. Further, because the tubular apparatus is made of modular elements, the tubular apparatus is very versatile and can be used for various applications at various depths. Thus, a single tubular apparatus can be used multiple times for multiple applications. Moreover, the tubular apparatus's modular construction allows the separate components that comprise the chimney apparatus to be manufactured simultaneously by multiple suppliers, which reduces the manufacturing time and costs.
As depicted in
The base 2 can be any shape necessary to achieve its desired function but as shown in
As can be seen in
As will be apparent to those skilled in the art, additional anchoring means may be used to anchor the base 2. For example, metal baskets can be lowered from the surface to the ocean floor in a similar manner to the anchoring blocks. The baskets can also include sheaves similar to the anchoring blocks in order to receive the cables (see cables 11h and 11i). Once in position, ordinary anchor chain can be lowered into these metal baskets, thus forming the anchoring means. Accordingly, this type of anchoring means can be constructed quickly and easily transported to the deployment site and the weight can be tailored based on the desired application by the amount of anchor chain that is lowered into the metal baskets. Further, for more permanent operations, instead of anchoring blocks or baskets, moorings can be constructed into the ocean floor
At or near the water surface is included a surface structure or a means 6 for collecting or storing the recovered oil or other fluids. As depicted in
As depicted in
One embodiment of the collecting means 6, operates as follows. Oil that enters the base 2 of the chimney apparatus 1 rises to the surface as a result of its natural buoyancy in seawater. At the surface, the collecting means 6 contains the oil within its boundaries. Because the oil is less dense than the seawater, the oil forms a layer on top of the sweater at the surface. The more oil, the deeper the layer of oil. The layer of oil can then be siphoned off the water surface and pumped into a recovery tanker or vessel.
As can be seen in
The connecting rings, 12a, 12b, 12c, 12d, are designed to withstand radial tension or compression and can be made from different materials depending on the intended use of the chimney apparatus 1 and/or the duration of submersion. Examples of these materials include metals such as steel, aluminum and/or other metals and alloys, laminated woods that can advantageously be used for their natural buoyancy, reinforced composite materials that include preforms woven from glass, ceramics, carbon, aramid, polyethylene, etc. and embedded in a matrix material such as an epoxy resin.
As previously disclosed, the modular elements, 5a, 5b, 5c, 5d, 5e, that form the tubular apparatus 1, are joined together using a plurality of connecting rings, 12a, 12b, 12c, 12d. As depicted in
Depicted in
In another embodiment, as depicted in
Having a two-piece connecting ring makes joining the modular elements together during the deployment process (discussed below) easier and quicker, thus reducing deployment time. Deployment time is reduced because each half of the connection ring can be attached to a modular element on shore prior to deployment. Then, during deployment, each half of the connecting ring can be joined together, for example, in the manner described above, which is quicker and easier than joining the ends of adjacent modular elements to a single connection ring through clamping, which may require the use of hundreds of screws for each end of the modular elements.
In another embodiment, the connecting rings, 12a, 12b, 12c, 12d, can be a torus-shaped fabric structure that is filled and inflated with water and super pressurized by one or two pairs of bladders filled with oil where at least one bladder is included in the torus-shaped structure and at least another bladder is located 20 to 40 m deeper. These bladders are connected to each other with a hose, pipe or other similar structure. The difference in densities between oil and sea water at this depth generates 400 to 800 millibars of suppression in the torus, regardless of depth. That is, water pressure on the lower bladder is transmitted to the upper bladder in the torus through the hose or pipe that connects the two bladders. This occurs because, as previously discussed, oil is less dense than water and thus, for every 20 meters of depth, 2 bars of water pressure is created. Thus, a 20 m difference in depth between the oil in the 2 bladders produces 1.6 bars of pressure (density=0.8 kg/dm3). Therefore, the pressure in the upper bladder is 0.4 bars (or 400 millibars) more than that of the water surrounding the torus, which provides the surpression or stiffness.
As shown in
To help reinforce each individual modular element, 5a, 5b, 5c, 5d, 5e, as depicted in
Depicted in
The materials used to construct the modular elements, 5a, 5b, 5c, 5d, 5e, and the base 2, can be textile fabrics made of synthetic yarns and are such that the fabrics are impermeable to fluids, i.e., seawater and oil. Accordingly, the column of water created by the tubular apparatus, is isolated from the surrounding water and, as a result, prevents the surrounding water from becoming contaminated with any oil or other contaminants that enter and rise up the tubular apparatus. Thus, the tubular apparatus can be used to form an impermeable barrier between the column of water contained on its interior and the water on its exterior.
The fabric can be a pre-stressed fabric, for example, Préconstraint® 1502 from the Ferrari® Textiles Corp. The internal side of the fabric, i.e., the side of the fabric on the interior of the modular elements or base, can be coated with an anti-adhesive coating or laminated with an oil repellant in order to prevent the oil or other fluids from adhering or sticking to the interior surfaces of the tubular apparatus 1 as the oil or fluids ascend within the tubular apparatus 1. Examples of this coating include, and are not limited to Tedlar® and Teflon® from DuPont™, PTFE (polytetrafluoroethylene), silicone, and any other coating that has anti-adhesion properties. The anti-adhesive coatings as well as additional coatings, can be used to help render the modular elements and the base of the chimney apparatus impermeable to water and other fluids.
Although embodiments of the present invention have been described as having fabric or textile components, as will be apparent to those skilled in the art, additional materials may be used.
Some applications may require that the tubular apparatus 1 have thermal insulative properties either (1) to protect against the colder water at the deeper portions of the tubular apparatus 1 and thereby prevent any gas associated with leaking oil from crystallizing or (2) to keep the deeper water cold as it rises to the surface so it can be used in an OTEC or SWAC process. As depicted in
A non-limiting example of a structure constructed in accordance with embodiments of the present invention will now be discussed with reference to
The base 2 is made from the same fabric as the modular elements and has a bottom diameter of 120 m and a top diameter of 12 m corresponding to the diameter of the first connection ring 5a, which is connected to the top of the base 2. A base 2 of this size has an approximate weight of 25 to 30 metric tons. In order to connect the modular elements to each other and to the base 2, 75 connection rings will be used, each having a diameter of 12 m. In one embodiment, the connection rings will be aluminum and will have a height of approximately 55 cm. As depicted in
Deployment of the tubular apparatus 1 according to an embodiment of the present invention will now be described with reference to
Because the modular elements are made from a fabric material, each modular element can be folded onto itself within its connection rings thereby forming a folded structure that is very compact and does not take up much space (when folded, the volume of each modular element is reduced by approximately 90%). The base 2 can also be folded and stored in a similar manner. Because the elements of the chimney apparatus 1 can be folded and thus, reduced in volume, storage costs are reduced. When needed, all of the chimney apparatus 1 components are loaded onto the specially adapted barges or platforms and brought out to the recovery site. Again, because the components can be folded and their volumes reduced, more components can be included on fewer barges or platforms reducing deployment costs and deployment times as less trips to the deployment site will be necessary.
Once at the deployment site, the anchoring blocks, 3a, 3b, 3c, 3d, 3e, 3f, 3g, are positioned on the ocean floor 4 around the recovery area. Connected to the anchoring blocks, 3a, 3b, 3c, 3d, 3e, 3f, 3g, by way of sheaves or other similar device, 26a and 26b, are a plurality of cables or ropes, 11a, 11b, 11c, 11d, 11e, 11f, 11g. One end of these cables or ropes, 11a, 11b, 11c, 11d, 11e, 11f, 11g, fixedly attach to the bottom of the base 2 by way of connecting rings, 14a, 14b, 14c, 14d, 14e, 14f, 14g, and the other end of the cables or ropes attach to winches, capstans or hydraulic jacks included on the barges or platforms. The length of cables or rope required for the ocean depth at the recovery site is also stored on these winches, capstans or drums included on the barges or vessels. Connecting the cables or ropes to the anchoring blocks, the base 2, and the winches, capstans, or hydraulic jacks, allows the anchoring blocks with the ropes or cables connected through the sheaves first to be lowered into position on the ocean floor and then permits the base and modular elements to be lowered to the ocean floor only after all of the anchoring blocks are positioned. In other words, connecting the ropes or cables to the anchoring blocks is not a two step process. Because sheaves are used, the anchoring blocks can be lowered in position with the ropes or cables attached, without dragging the base along with them. Thus, because the ropes or cables are already attached to the anchoring blocks through the sheaves, after the anchoring blocks are positioned, a separate procedure is not required to attach the cables to the already positioned anchoring blocks.
Once the anchoring blocks are positioned, the base 2 and connected modular elements can then be winched down into position on the ocean floor. During the winching process, the cables or ropes, one end of which is attached to the winches, capstans or hydraulic jacks, and the other end of which is attached to the base 2, travel through the sheaves on the anchoring blocks and are taken in by the winches, capstans, or hydraulic jacks, thereby causing the base 2 to be pulled down towards the anchoring blocks into position. When modular units are added to the tubular apparatus 1, the shackles 210 on the connecting rings (see
During the deployment process, as the base 2 is winched down into position on the ocean floor, each modular unit is attached to the preceding modular unit by way of the connecting rings. Thus, the tubular apparatus 1 is essentially constructed on site as it is being lowered into position.
As previously discussed, embodiments of the present invention avoid the gas crystallization problems of prior devices. Additional reasons as to why crystallization of gas is not an issue with the present chimney apparatus include (1) the large diameter of the vertical column formed by the base and the modular elements, minimizes if not eliminates any possibility of any crystals that form from obstructing the chimney apparatus and (2) as any crystals that form rise to the surface within the vertical column, the seawater in the column, which naturally warms up closer to the surface, also warms the crystals causing the crystals to regenerate as a gas. Any crystals that do make it to the surface can be collected and burned off. Essentially, the large diameter of the chimney apparatus permits the leaking oil and any gas crystals that form, to behave as they normally would in the open ocean.
In order to avoid any possibility of leaking oil from escaping and polluting the oceans during offshore drilling operations as a result of damage to the subsurface well or piping, the present chimney apparatus could be used as a permanent containment vessel that encloses all of the oil piping, structures and equipment that extend from the oil rig to the well on the ocean floor. Thus, any leaking oil would rise within the column of water formed by the chimney apparatus and would be collected or contained at the surface by a collecting means 6. Any oil collected by the collecting means 6, would then be pumped or siphoned off into the regular components on the oil rig that are used to retrieve and collect oil from the well. In addition to providing a containment vessel for leaking oil, the chimney apparatus would, as discussed above, provide a column of calm water around the oil piping, thereby sheltering the piping from rough sea conditions and possible damage. The oil piping can be stabilized and/or centered within the chimney apparatus by structures that attach to the piping and the connecting rings of the modular elements.
If the tubular apparatus disclosed herein is used for OTEC or SWAC, the collecting means 6 at the top of the tubular apparatus 1 may not be necessary. Instead, the last or topmost modular element may form a surface structure that can be connected to the OTEC or SWAC platform or plant for delivery of the cold seawater.
Not only can the present tubular apparatus 1 be used to collect and transport fluids vertically as depicted in
In one embodiment, as depicted in
In another embodiment where the tubular structure 1 is naturally buoyant, as depicted in
In another embodiment depicted in
Because horizontal or inclined tubular structures cannot be tensioned by gravity like vertical tubular structures, axial tensioners must be employed. These tensioners are used to adjust the length of the tubular structure and are in the form of specially constructed modular elements.
Although a preferred embodiment of the present invention and modifications thereof have been described in detail herein, it is to be understood that this invention is not limited to these precise embodiments and modifications, and that other modifications and variations may be effected by one skilled in the art without departing from the spirit and scope of the above-discussed embodiments of the invention. For example, the embodiments of the present invention could also be used to recover oil and/or to provide an isolated column of water in lakes.
This application claims the benefit of U.S. Provisional Application No. 61/357,691, filed Jun. 23, 2010, the entire contents of which are incorporated herein by reference in its entirety.
Number | Date | Country | |
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61357691 | Jun 2010 | US |