US3592005A

US3592005A - Oil barrier for offshore oil rigs

Info

Publication number: US3592005A
Application number: US801985A
Authority: US
Inventors: Eugene C Greenwood
Original assignee: FRE DEL ENGINEERING CORP
Current assignee: FRE DEL ENGINEERING CORP; FRE-DEL ENGINEERING CORP
Priority date: 1969-02-25
Filing date: 1969-02-25
Publication date: 1971-07-13
Anticipated expiration: 1988-07-13

Abstract

A floating barrier is anchored in place in a generally circular shape around an offshore oil rig. The barrier consists of a plurality of rigid segments extending above and below the surface of the water and attached to each other by flexible couplings which permit movement in both horizontal and vertical planes. At each joint, a sheet of flexible material seals the joint from an interchange of oil and water from the inside of the barrier to the outside.

Description

United States Patent [56] References Cited UNITED STATES PATENTS [72] Inventor Eugene 0 Greenwood Newport Beach, Calif. [211 App]. No. 801,985

[22] Filed Feb. 25, 1969 [45] Patented July 13, 1971 [7 3] Assignee F re-Del Engineering Corporation Santa Ana, Calif. a part interest ABSTRACT: A floating barrier is anchored in place in a OIL BARRIER FOR OFFSHORE OIL RGs generally circular shape around an offshore oil rig. The barrier consists of a plurality of rigid segments extending above and Claims 9 Drawing Figs below the surface of the water and attached to each other by flexible couplings which permit movement in both horizontal and vertical planes. At each joint, a sheet of flexible material seals the joint from an interchange of oil and water from the inside of the barrier to the outside.

[51] Int. [50] Field of Search........

PATENTED JUL13I9Y| $592,005

SHEET 1 [1F 3 INVENTOR.

EUGENE C. GREENWOOD ATTORNEYS PATENTEU JUL 1 3 l9?! JSHEU 2 OF 3 m 5 0L.\ 0 5 2 r K 9 4 2 4 m f M 1 o J- 4 5 2 11 4 1 I 8 1 4 7 O 5 9 I 4 l O 2 2 l I 6 \/l\ a g G l m F h INVENTOR.

EUGENE c. GREENWOOD ATTORNEYS FIG. 2

PATENTED JUL 1 3191:

SHEEI 3 [IF 3 INVENTOR.

E UGENE C. GREENWOOD @Z Z i M FIG. 9

ATTORNEYS- OIL BARRIER FOR OFFSHORE OIL RIGS BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and means for preventing escape of oil from offshore oil rigs and, more particularly, to an oil barrier extending both above and below the water completely around an offshore drilling platform so as to prevent escape of floating oil from the vicinity of the platform.

2. Description of the Prior Art In recent years, a substantial effort has been made to harvest the vast oil resources which exist beneath the ocean floors. Most large scale attempts to reach the oil include the construction of a drilling platform placed on the ocean floor and extending above the surface of the water. Equipment is mounted on the platform for drilling through the ocean floor until the oil pocket is reached, whereupon the oil is pumped either onto tankers or directly to shore through underwater pipelines.

There are many dangers inherent in such an operation. As demonstrated time and again, one of the greatest dangers is that oil will leak, spill or blow out from a well. Since oil is lighter than water, the escaping oil immediately floats to the surface of the water and begins to disperse in a direction determined by the wind and prevailing currents. Very often the oil is blown ashore thereby ruining beaches, docks, boats, etc. In addition, the oil presents a serious hazard to existing wildlife. Birds landing on the water become coated with the oil and usually die. To prevent this, detergents are often sprayed onto the oil to make the oil sink. However, this is damaging to the plants and other animal life which exist on the ocean floor.

To date, no serious attempts have been made to solve this problem. When an underwater well begins to leak, spill or blow out, the only available procedure is to try and plug the well. This may be done in many ways but is usually done by pumping mud or other materials into the well. However, this procedure usually takes many days during which time the oil is constantly flowing into the water thereby spreading its destruction in all directions.

SUMMARY OF THE INVENTION According to the present invention, there is provided a technique which, although in no way preventing oil from leaking, spilling or blowing out from an underwater well, will effectively confine the oil within a predetermined space from where it may be easily pumped from the surface into tankers, etc. By providing a technique for trapping leaking oil, the problem of offshore oil wells blowing becomes insignificant, since the only real danger associated with the oil leakage is the fact that the spreading oil causes a hazard to animal and plant life and the coastline.

Briefly, the present invention comprises a barrier which is anchored in place in a generally circular shape around a drilling platform. The barrier is light enough in weight to float on the water and consists of a plurality of steel segments attached to each other by flexible couplings which allow movement in both horizontal and vertical planes. The barrier extends both above and below the water, the section above the water preventing the oil from splashing over the barrier, and the section below the water preventing the oil from becoming deep enough to pass beneath the barrier. Inside the barrier, at each joint, a sheet of flexible material seals the joint from interchange of oil or water from one side of the barrier to the other.

It is, therefore, an object of the present invention to provide an oil barrier for offshore oil rigs.

It is a further object of the present invention to provide means for preventing the escape of floating oil from the vicinity of an offshore oil rig.

It is a still further object of the present invention to provide a generally circular oil barrier around a drilling rig to trap oil which may leak, spill or blow out from an underwater well.

Still other objects, features and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiments constructed in accordance therewith, taken in conjunction with the accompanying drawings wherein like numerals designate like parts in the several figures and wherein:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of an oil barrier'constructed in accordance with the teachings of the present invention shown in place around a drilling platform;

FIG. 2 is an enlarged cross-sectional view taken along the line 2-2 in FIG. 1 showing a first embodiment for the individual segments of the barrier;

FIG. 3 is an enlarged cross-sectional view taken along the line 2-2 in FIG. 1 and showing a second embodiment for the individual segments of the barrier;

FIG. 4 is an enlarged plan. view of the barrier of FIG. 1 showing the flexible couplings between the individual segments thereof;

FIG. 5 is a view taken along the line 5-5 in FIG. 4 and showing the details of the coupling which permits movement in a vertical plane;

FIG. 6 is a view taken along the line 6-6 in FIG. 5;

FIG. 7 is a view taken along the line 7-7 in FIG. 4 and showing the details of the flexible coupling which permits movement in a horizontal plane;

FIG. 8 is a view taken along the line 8-8 in FIG. 7; and

FIG. 9 is an enlarged plan view of the gate portion of the present barrier showing the details of the sealing pin.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and, more particularly, to FIG. 1 thereof, there is shown a drilling platform 10 positioned on the floor of the ocean and extending above the surface of the water 12. Also shown is a barrier, generally designated 13, made up of a plurality of segments 14. Barrier 13 may have a diameter, for example, of from 500 to I000 feet which would permit it to contain any oil 15 which may leak, spill or blow out from the wells below platform 10. A plurality of anchors 16 (not shown) connected to segments 14 of barrier 13 by steel, cables 17 are located at intervals which are frequent enough to hold barrier 13 in place in the presence of expected currents, winds and wave forces. Steel cables 17, however, are loose enough or extensible enough to provide for changes in depth due to tides. If found necessary, anchors 16 may be set in concrete caissons poured on the ocean floor.

Referring now to FIGS. 1 and 2, since oil is lighter than water, any oil leaking, spilling or blowing out from an underwater well within the confines of barrier 13 will flow to the top and be contained by the barrier. For this reason barrier 13 is made of a plurality of segments 14 which are light enough in weight to float on the surface of water 12. As shown in FIG. 2, segments 14 extend both above and below the surface. According to a first embodiment, segments 14 may consist of half of a large diameter pipe 20, the open side of which is welded adjacent one end of a flat plate 21. Pipe 20, containing air, will float on the surface of water 12. A first section 22 of plate 21 will extend above the surface of water 12 and a second section 23 of plate 21 will extend below the surface of water 12. A typical height may be 2 to 3 feet above the surface of water 12 and 4 to 6 feetbelow the surface of water 12. Segments 14 may be as short as 2 or 3 feet in cases where very rough seas are usual or as long as 10 or more feet where ocean conditions are generally calm. In addition, a splash plate 24, may be welded at the top edge of section 22 of plate 21 to prevent wave action from forcing any oil 15 floating on the surface of water 12 from splashing over the top of barrier 13. A plurality of spaced gussets 25 may be utilized to support splash plate 24 relative to plate 21.

FIG. 2 also shows steel cables 17 attached to a ring 26 on pipe 20 to hold barrier 13 anchored in place around drilling platform 10. A plurality of buoys 27 attached to cables 17 and spaced from pipe 20 may be provided to support cables 17 so that the weight of cables 17 does not pull barrier 13 underwater. In this manner, a loop may be provided between cable support buoy 27 and pipe 20 to provide for changes in depth of barriers 13 due to tides.

With barrier 13 in place, any oil 15 seeping, leaking or blowing out from the well beneath platform will be effectively contained within the confines of barrier 13. From this trapped location, oil may easily be pumped from the surface onto tanker 18 where it may be simply separated from the water and carried to shore. For example, the famous Santa Barbara Channel oil blowout which occurred during Jan. 1969, could have been contained in a 500 foot diameter circular barrier since the 500 barrels per day which were emanating from the ocean floor would have only caused an oil accumulation of approximately is inch per 24 hours. A siphoning ship outside of barrier 13 could have easily cleaned this up each day.

Referring now to FIG. 3, there is shown an alternate embodiment for individual segments 14. According to the embodiment of FIG. 3, segments 14 consist of a large diameter pipe 30 having a first flat steel plate 31 extending from the bottom thereof and a second, smaller steel plate 32 extending from the top thereof. In addition, rather than providing a separate splash plate welded to the top of plate 32 and supported by gussets as in FIG. 2, the upper end of plate 32 may be bent to provide a curved section 33 which will effectively operate as a splash plate.

Referring now to FIG. 1, individual segments M are attached to each other by flexible couplings 40 and 411, and a removable gate coupling 60, flexible couplings 4M) permitting segments 14 to move in a vertical plane and flexible couplings -11 pennitting segments M to move in a horizontal plane to give the entire barrier 13 the necessary degree of flexibility to permit motion due to wave forces.

Referring now to FIGS. 5 and 6, flexible couplings 40 are constructed so that adjacent segments 14 are permitted relative motion in a vertical plane. At the end of alternate segments 14, pipes are sealed with semicircular plates 42. The remainder of plates 21 beyond the ends of plates 12 overlap by an amount d, the overlapping sections extending the entire height of plates 21. An additional plate section 43, attached to semicircular plate 412 of one of segments 14 and supported by gussets 44, is positioned parallel to the overlapping sections adjacent the section of the other segment 14. In this manner, a simple dovetail interlocking joint is formed. A rivet or bolt 45 extending through the overlapping sections of plates 21 and plate 413 provides a pivot point to permit segments M to flex in a vertical plane. In addition, splash plates 24 are omitted within the overlapping area d to prevent interference therebetween in the presence of flexure of the segments.

Positioned inside barrier 13, at each flex joint, is a sheet of flexible material 411 attached between adjacent segments M so as to seal

joints

40 and 41 to prevent an interchange of water and oil from one side of the barrier to the other. Sheet 68 may be made of a tough, flexible material such as rubber, vinyl or plastic impregnated cloth. Sheets 48 may be secured to adjacent segments 14 using thin, steel strips 49. The opposite ends of sheet 48 are positioned between plates 21 of segments 14 and strips 49 whereupon strips 49 are secured to plates 21 with rivets 50 thereby squeezing the ends of sheet 63 between plate 21 and strip 49 to provide a watertight seal.

Referring now to FIGS. 7 and d, flexible couplings 41 are constructed so that adjacent segments 14 are permitted relative motion in a horizontal plane. At the end of alternate segments M, pipes 20 are sealed with semicircular plates 70. The remainder of plates 21 beyond the ends of plates 70 are curved so as to provide adjacent sections 71 and 72 which are portions of a cylinder which may pivot with respect to each other about a pivot point 77 aligned with their center of curvature. Furthermore, segments 14 are provided with

horizontal backing plates

73 and 74, respectively, which are secured to plates and supported by gussets 75, backing plate 7 also being secured to section 72. Plates 73 and 741 overlap in the vicinity of pivot point 77, so that a flex pin 76 may be inserted therethrough at centerline 77. Therefore, and as shown in FIGS. 7 and 8, segments 14 may pivot in a horizontal plane about flex pin 76, curved segments 71 and 72 freely sliding across one another. In addition, as in FIGS. 5 and 6, a flexible sheet 48 secured by strips 419 land rivets 50 prevents leakage from one side of barrier 13 to the other.

Referring now to FIGS. 4 and 9, barrier 13 may be provided with a gate so that two adjacent segments 14 may be separated to permit a ship to come into and exit from barrier 113. Gate coupling 60 is identical to flexible coupling 41 except that flex pin 76 is replaced with an elongated gate pin 65 which may be removed to

separate plates

73 and 74. In addition, and as shown in FIG. 9, means are provided to permit the detachment of flexible barrier 48 from at least one of segments 14. This may be permitted by providing one end of sheet 48 with a loop 61 and by providing a clamp member 62 secured to plate 21 by rivets 63. The diameter of loop 61 and the spacing between clamp member 62 and sheet 21 is such that a sealing pin 64 extending through loop 61 will slightly compress the material in loop 61 between member 62 and sheet 21, thereby securely clamping the one end of sheet 48 and providing a watertight seal. On the other hand, gate 60 may be readily opened by removing seal pin 64 and gate 65 whereupon segments M may be swung inwardly or outwardly to provide an opening in barrier 13 through which a ship may pass.

While the invention has been described with respect to several physical embodiments constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention.

Iclaim:

1. Apparatus for confining floating oil within a predetermined space comprising a floating barrier extending entirely around said predetermined space, said barrier consisting of a plurality of segments, each of said segments comprising a hollow, substantially semicylindrical member and a flat plate, the opposite edges of said member being connected to said plate to form an airtight float, said segments being interconnected by flexible couplings which permit relative motion of said segments in both horizontal and vertical planes.

2. Apparatus according to claim 1 wherein the upper end of said flat plate is curved toward the center of said predetermined space thereby forming a splash guard.

3. Apparatus according to claim 1 further comprising a second substantially flat plate, said second plate being connected to the upper edge of said first-mentioned flat plate, said second flat plate extending toward the center of said predetermined space thereby forming a splash guard.

4. Apparatus according to claim 1 wherein each of said semicylindrical members is sealed at the opposite ends thereof with a semicircular plate connected thereto and wherein said flexible couplings which permit relative motion of said segments in a vertical plane comprise a dovetail interlocking joint connected to the ends of adjacent segments and a rivet or bolt extending through said joint.

5. Apparatus according to claim 4 wherein said dovetail joint comprises a first plate section attached to the end of one of said segments and extending beyond said semicircular plate, and a pair of spaced second plate sections attached to the end of the other one of said segments and extending beyond said semicircular plate, said first plate section fitting between said pair of second plate sections, said rivet or bolt extending through said first and second plate sections to provide a pivot point to permit said segments to flex in a vertical plane.

6. Apparatus according to claim 5 wherein said first and second plate sections are aligned in a substantially vertical plane and wherein said rivet or bolt extends in a substantially horizontal plane.

7. Apparatus according to claim 1 wherein each of said semicylindrical members is sealed at the opposite ends thereof with a substantially semicircular plate connected thereto and wherein at said flexible couplings which pennit relative motion of said segments in a horizontal plane a portion of said flat plates extend beyond said semicircular plate, said portions being curved to form a section of a cylinder, the cylindrical portions of adjacent segments being in contact, and wherein said flexible coupling further comprises a generally horizontal backing plate secured to each of said adjacent segments, said backing plates being connected to said cylindrical portions and overlapping, and a rivet or bolt extending through said overlapping backing plates at the center of curvature of said cylindrical portions whereby said segments may pivot in a horizontal plane about said rivet or bolt.

8. Apparatus for confining floating oil within a predetermined space comprising a floating barrier extending entirely around said predetermined space, said barrier consisting of a plurality of segments, each of said segments comprising a hollow, cylindrical member, a first substantially flat, elongated plate connected to one side of said cylindrical member, and a second substantially flat, elongated plate connected to the opposite side of said member, said cylindrical member adapted to float with said first plate above the water and said second plate below the water, said segments being interconnected by flexible couplings which permit relative motion of said segments in both horizontal and vertical planes.

9. Apparatus according to claim 8 wherein the upper end of said plat plate is curved toward the center of said predetermined space, thereby forming a splash plate.

10. Apparatus according to claim 8 further comprising a third substantially flat, elongated plate, said third plate being connected to the upper edge of said first plate, said third plate extending toward the center of said predetermined space, thereby forming a splash guard.

Claims

7. Apparatus according to claim 1 wherein each of said semicylindrical members is sealed at the opposite ends thereof with a substantially semicircular plate connected thereto and wherein at said flexible couplings which permit relative motion of said segments in a horizontal plane a portion of said flat plates extend beyond said semicircular plate, said portions being curved to form a section of a cylinder, the cylindrical portions of adjacent segments being in contact, and wherein said flexible coupling further comprises a generally horizontal backing plate secured to each of said adjacent segments, said backing plates being connected to said cylindrical portions and overlapping, and a rivet or bolt extending through said overlapping backing plates at the center of curvature of said cylindrical portions whereby said segments may pivot in a horizontal plane about said rivet or bolt.