Abstract
A containment boom is for confining an oil spill within a restricted area on a water surface, wherein the containment boom has an openable link and connection means for connecting the containment boom at each side of the link to separate towing vessels. A system is for confining an oil spill having the containment boom and a storage means for storing the containment boom, wherein the storage means is configured to be situated at the perimeter of an offshore structure above the water surface, and wherein the lower part of the storage means is configured to be able to be opened and release the containment boom into the water upon deployment of the system. An offshore structure includes the system. A method is for confining an oil spill using the system.
Claims
1. A containment boom for confining an oil spill within a restricted area on a water surface, the containment boom comprising an openable link and connection means for connecting the containment boom at each side of the link to separate towing vessels wherein the openable link is remotely openable.
2. The containment boom according to claim 1, wherein the openable link is a weak link configured to break open when a tension above a threshold value across the weak link is applied.
3. A system for confining an oil spill, the system comprising a containment boom, wherein the containment boom comprises an openable link and connection means for connecting the containment boom at each side of the link to separate towing vessels wherein the openable link is remotely openable, and a storage means for storing the containment boom, wherein the storage means is configured to be situated at a perimeter of an offshore structure above the water surface, and wherein the storage means is configured to be able to release the containment boom into the water upon deployment of the system.
4. The system according to claim 3, wherein the system comprises an oil sensor for being positioned at the water surface and for transmitting a signal if an oil spill is detected.
5. The system according to claim 4, wherein the system comprises at least two oil sensors.
6. The system according to claim 3, wherein the containment boom is in a deflated configuration while stored by the storage means and configured to be automatically inflated upon deployment.
7. The system according to claim 3, wherein the system further comprises delivering means for delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom.
8. The system according to claim 7, wherein the delivering means comprises a pneumatic line thrower.
9. An offshore structure comprising a system for confining an oil spill, the system comprising the containment boom, wherein the containment boom comprises an openable link and connection means for connecting the containment boom at each side of the link to separate towing vessels wherein the openable link is remotely openable and a storage means for storing the containment boom, wherein the storage means is configured to be situated at a perimeter of an offshore structure above the water surface, and wherein the storage means is configured to be able to release the containment boom into the water upon deployment of the system.
10. A method for confining an oil spill using a system comprising the containment boom, wherein the containment boom comprises an openable link and connection means for connecting the containment boom at each side of the link to separate towing vessels wherein the openable link is remotely openable and a storage means for storing the containment boom, wherein the storage means is configured to be situated at a perimeter of an offshore structure above the water surface, and wherein the storage means is configured to be able to release the containment boom into the water upon deployment of the system, wherein the method comprises the steps of: releasing the containment boom from the storage means; delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom; and opening the link and moving the oil spill away from offshore structure by the towing vessels using the connection means.
11. The method according to claim 10, wherein the system further comprises delivering means for delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom, and wherein the step of delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom includes using the delivering means.
12. The system according to claim 4, wherein the containment boom is in a deflated configuration while stored by the storage means and configured to be automatically inflated upon deployment.
13. The system according to claim 5, wherein the containment boom is in a deflated configuration while stored by the storage means and configured to be automatically inflated upon deployment.
14. The system according to claim 4, wherein the system further comprises delivering means for delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom.
15. The system according to claim 5, wherein the system further comprises delivering means for delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom.
16. The system according to claim 6, wherein the system further comprises delivering means for delivering to separate towing vessels the ends of the connection means which are opposite to the containment boom.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] In the following is described an example of preferred embodiments illustrated in the accompanying drawings, wherein:
[0026] FIG. 1 shows an oil rig viewed from above with a storage means installed at the perimeter of the oil rig (FIG. 1A) and after a containment boom has been released (FIG. 1B);
[0027] FIG. 2 shows, on a larger scale, an embodiment of the remotely openable link in the form of a weak link in the containment boom;
[0028] FIG. 3 shows a cross-sectioned view of an embodiment of system according to the second aspect of the invention (FIG. 3A), with the release mechanism viewed from a different angle (3B);
[0029] FIG. 4 shows a cross-sectioned view of another embodiment of the system according to the second aspect of the invention;
[0030] FIG. 5 shows another embodiment of the system according to the second aspect of the invention;
[0031] FIG. 6 shows, on the same scale as in FIG. 2, an embodiment of the remotely openable link comprising a pin bolt;
[0032] FIG. 7 shows on the same scale an embodiment of the remotely openable link comprising a remote release clamp;
[0033] FIG. 8 shows on the same scale an embodiment of the remotely openable link comprising a cutting tool;
[0034] FIG. 9 shows on the same scale an embodiment of the remotely openable link comprising an electromagnet; and
[0035] FIG. 10 shows on the same scale an embodiment of the remotely openable link comprising two permanent magnets.
DETAILED DESCRIPTION OF THE DRAWINGS
[0036] In the drawings, the reference numeral 1 indicates a containment boom according to the invention. The drawings are shown in a schematic manner, and the features therein are not necessarily drawn to scale.
[0037] FIG. 1A shows an oil rig 3 viewed from above comprising a storage means 5 for a containment boom 1 (not visible in FIG. 1A). The storage means 5 is configured to be able to release the containment boom 1 quickly into the water, see for example FIG. 3. The storage means 5 is positioned along the entire perimeter of the oil rig 3 to be able to store a continuous containment boom 1. Thereby, as shown FIG. 1B, if an oil spill 7 has occurred, the containment boom 1 is released from the storage means 5 and falls into the water. The containment boom 1 thereby encircles the oil rig 3 and the spilled oil 7. The containment boom 1 comprises a weak link 9 which will open if a tension above a pre-set threshold is applied across the weak link 9. The containment boom 1 additionally comprises connection means 11, for example pennant lines, for connecting the containment boom 1 at each side of the weak link 9 to separate towing vessels 13. Towing vessels 13 can thereby open the containment boom 1 simply by pulling in the connection means 11, which will apply a tension across the weak link 9. Optionally, the connection means 11 may be delivered to the towing vessels 13 using delivery means such as pneumatic line throwers (not shown).
[0038] FIG. 2 shows, on a larger scale, a possible design of the weak link 9 in the containment boom 1. The containment boom 1 comprises a floatable portion 15, which is configured to emerge above the water surface to prevent spilled oil from escaping above the containment boom 1, and a skirt 17 configured to extend to a pre-set depth below the water surface to prevent spilled oil from escaping below the containment boom 1. The floatable portion 15 may for example be inflated with air or another gas to float, whereby it may be in a deflated state to save space when it is not yet deployed. The skirt 17 comprises a weight 19, which is denser than water, at the bottom end to ensure that the skirt 17 extends into the water. Such a design is typical for a containment boom 1 and is not especially related to the shown design of the weak link 9. The weak link 9 comprises at one side an arrow-shaped portion 21 which is inserted into a complementary-shaped recess 23 at the other side (shown with its cross-section in the figure to make the recess 23 visible). The recess 23 is shaped such that the arrow-shaped portion 21 cannot escape, unless a tension above a pre-set threshold is applied across the weak link 9, whereby the weak link 9 will open. The weak link 9 may for example be constructed to break if the threshold is exceeded, or the arrow-shaped portion 21 may be constructed in a material which allows it to deform elastically if the threshold is exceeded. If it opens by temporary elastic deformation, the weak link 9 has the advantage that it may be closed again and reused, for example after the oil spill 7 has been moved. The tension across the weak link 9 may be applied by pulling in the connection means 11 connected at each side of the weak link 9.
[0039] FIG. 3A shows a cross-sectioned view of a system 25 according to the second aspect of the invention comprising a containment boom 1 within a storage means 5, here in the form of a storage box. The containment boom 1 comprises a floatable portion 15, a skirt 17, and a weight 19 as shown in FIG. 2 and described above. The storage means 5 is in the shown embodiment attached to a railing 27 of an oil rig 3. The bottom portion 29 of the storage means 5 is rotatably attached at one side via a hinge 31 and is supported by a support rod 33 extending from the storage means 5 and connected to the oil rig 3 further below. The support rod 33 is rotatably attached at both the first end 35, which is attached to the bottom portion 29 of the storage means 5, and the second end 37, which is attached to the oil rig 3. The support rod 33 comprises a first portion 39 and a second portion 41 which are rotatably connected through a bolt 43 which extends through both portions 39, 41 of the support rod 33, see also FIG. 3B. A second bolt 45, which is controlled by a releaser 47, ensures that the two portions 39, 41 do not rotate relative to each other around the bolt 43. The releaser 47 is remotely controlled via a cable 49. If an oil spoil occurs and the system 25 is to be deployed, the second bolt 45 is removed by the releaser 47. The two portions 39, 41 of the support rod 33 are thereby free to rotate around the points 35, 43, and 37 which causes the support rod 33 to bend and the bottom portion 29 of the storage means 5 to fall down while rotating around the hinge 31. A plate 51 on the second portion 41 ensures that the support rod 33 can only bend in the desired direction. The containment boom 1 will thereby fall out of the storage means 5 and into the water. The weight 19 of the containment boom is positioned such that it is the first part of the containment boom 1 which starts falling, thereby assuring that the weight 19 reaches the water first and does not end above the floatable portion 15.
[0040] FIG. 4 shows another embodiment of the system 25 according to the second aspect of the invention. The system 25 is similar to the embodiment shown in FIG. 3A, but the release mechanism is different. In FIG. 4, the bottom portion 29 of the storage means 5, which is still rotatably attached at one side via a hinge 31, is held closed via for example a rope 51 strapped between a point 53 on the lower portion 29 of the storage means 5 and a point 55 on the upper portion 57 of the storage means 5. The rope 51 may also be e.g. a belt. A release unit 59 is configured to cut the rope 51 upon recieval of a signal, whereby the bottom portion 29 of the storage means 5 will rotate around the hinge 31 and release the containment boom 1. The release unit 59 may be of a type known in the art and may be activated for example electrically through a cable 61. The release unit 59 may additionally be configured to activate automatically and release the containment boom 1 if subjected to an increased pressure, for example due to hydrostatic pressure of the water if the offshore structure is sinking, as this may cause an increased risk of oil spill.
[0041] FIG. 5 shows another embodiment of the system 25 according to the second aspect of the invention. In this embodiment, the storage means 5 comprises a frame 63, and the containment boom 1 is tied to the frame 63 by a rope 65 or similar. The frame 63 can for example be attached to a railing 27. A release unit 59 is configured to cut the rope 65 upon recieval of a release signal through the cable 61. When the rope 65 is cut, the containment boom 1 is free to fall into the water below. Several frames 63 and ropes 65 may be positioned around the perimeter of the offshore structure.
[0042] FIG. 6 shows a remotely openable link 9 comprising a pin bolt 71 which holds the two ends of the containment boom 1 together by extending through eye bolts 73 on each end of the containment boom 1. The remotely openable link 9 may thereby be opened by pulling the pin bolt 71 out of the eye bolts 73 via a release rope 77, for example from a rig. The end of the pin bolt 71 opposite the release rope 77 includes a safety pin 75 which prevents the pin bolt 71 from escaping the eye bolts 73 unintentionally. The safety pin 75 is constructed to break or bend if a force above a threshold value is applied by pulling on the release rope 77, whereby the pin 71 bolt is removed and the link 9 opened.
[0043] FIG. 7 shows a remotely openable link 9 comprising a remote release clamp 79 connecting eye bolts 73 on each end of the containment boom 1, wherein the remote release clamp 79 may be released from at least one of the eye bolts 73 by pulling in a release rope 77. The remote release clamp 77 additionally comprises a safety pin 75 which must be pulled out with an additional safety line 81 before the release clamp 79 can be released by the release rope 77. The remote release clamp 79 comprises a release lever 83 whereon the release rope 77 pulls.
[0044] FIG. 8 shows a remotely openable link 9 wherein the two ends of the containment boom 1 are sewn together by a rope 85, and wherein an electrically operable cutting tool 87, shown as a pair of scissors, is adapted to cut the rope 85 between the two ends of the containment boom 1 to open the boom 1. The cutting tool 87 is activated through a wire 89.
[0045] FIG. 9 shows a remotely openable link 9 wherein the two ends of the containment boom 1 are held together by an electromagnet 91 at one end which acts on a suitable metal or alloy 93 at the other end of the containment boom 1. The remotely openable link 9 may be opened by turning off the current to the electromagnet 91 via a cable 95, whereby the magnetic force is eliminated.
[0046] FIG. 10 shows a remotely openable link 9 wherein the two ends of the containment boom 1 are held together by two permanent magnets 97, one at each end of the containment boom 1. This remotely openable link 9 is also a weak link, since the link will open if a predetermined threshold value which is greater than the magnetic force is applied. An advantage of a weak link 9 using magnets 97 is that it may easily be closed again.
[0047] It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements.
