US3066325A

US3066325A - Replaceable marine marker

Info

Publication number: US3066325A
Application number: US43578A
Authority: US
Inventors: William J Hayes
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1960-07-18
Filing date: 1960-07-18
Publication date: 1962-12-04
Anticipated expiration: 1979-12-04
Also published as: GB939712A

Description

Dec. 4, 1962 w. J. HAYES REPLACEABLE MARINE MARKER 5 Sheets-Sheet 1 Filed July 18, 1960 FIG. I

INVENTOR:

WILLIAM J. HAYES IS AGENT Dec. 4, 1962 w. J. HAYES 3,066,325

REPLACEABLE MARINE MARKER Filed July 18, 1960 3 Sheets-Sheet 2 II I 0' 24 460 4440 /45u FIG. 2

INVENTOR:

WILLIAM J. HAYES MW a42 HIS AGENT Dec- 4, 1962 w. J. HAYES 3,066,325

REPLACEABLE MARINE MARKER Filed July 18, 1960 5 Sheets-Sheet 5 FIG.3

INVENTOR:

WILLIAM J. HAY ES IS AGENT rates Patent time ware

Filed July 18, 196i), Ser. No. 43,578 8 Claims. (Cl. 9-8) This invention relates to marine markers and pertains more particularly to a marine marker buoy assembly for marking an underwater installation, such for example, as a wellhead assembly positioned on the ocean floor at the top of a well that has been drilled and completed therein.

Oil and gas wells located in deep offshore waters are generally drilled and completed in a manner whereby the entire operation is carried out underwater and the final wellhead assembly including production controls are positioned beneath the surface of the body of water, generally on the ocean floor. From time to time it is necessary to go back to these wells, locate them from a surface vessel, and carry out maintenance and servicing operations from a suitable barge floating on the surface of the water. It is therefore quite apparent that it is necessary to mark each well installation in some suitablemanner', as by the use of a permanent buoyattached to the wellhead, or to provide some other method or apparatus by which these underwater wellhead assemblies maybe readily located so that -a physical connection may be made with them. Buoys that are-permanently anchored to well installations have been used in the past with the buoy floating at all times on the surface of the water, but in some installations these buoys, together with their anchor line or cable, have proved to be a hazard to navigation.

It is therefore a primary object of the present invention to provide a marine marker or buoy which is releasably secured to an underwater installation in a manner whereby it may be readily released and allowed to float to the surface of the water when it is desired to establish physical contact with the underwater installation to which it is connected.

A further object of the present invention is to provide a method and apparatus for remotely installing from a surface vessel a marine marker or buoy on an underwater installation without the necessity of employing a diver to connect the buoy to the underwater installation.

Another object of the present invention is to provide a marine marker adapted to pass down through the Water along a buoy line and attach itself and its cable to an underwater marine installation while at the same time disconnecting the buoy line from the same installation.

These and other objects of this invention will be understood from the following description taken with reference to the drawing wherein:

FIGURE 1 is a view taken in partial longitudinal crosssection of the buoy apparatus of the present invention;

FIGURE 2 is a view taken in partial longitudinal crosssection of one form of a buoy container of the presentinvention that is adapted to be fixedly secured to an underwater installation; and,

FIGURE 3 is a view taken in partial longitudinal crosssection of the marine buoy apparatus of FIGURE 1 locked within the buoy container of FIGURE 2.

Referring to FIGURE 1 of the drawing, the buoy apparatus is illustrated as comprising a buoyancy tank 11, preferably spherical in design, and a buoy line housing 12 which are connected together by means of a tubular member 13 which extends axially through the buoyancy tank 11 and the buoy line housing 12, securing them together. The tubular element 13 may be welded to the buoy line housing 12 with the buoyancy tank 11 being held on the upper end of the tubular element 13 by any suitable means, as by a cap 14. Preferably, the-inside of the cap 14 is in the form of a fishing neck so as to facilitate removal of the buoy apparatus in the event that a fishing device has to be lowered down on an old buoy line 16 toretrieve the buoyancy apparatus. 7

As shown in FIGURE 1 the buoy apparatus is being lowered down over an old buoy line 16 with the-tubular element 13 serving as a central guide member along which the buoy apparatus slides as it is formed down through the Water by means of a weight 17 which is heavy enough to force the buoy apparatus down through the water. The weight 17 is preferably provided with a vertical central hole therethrough so that the old buoy line 16 may be threaded through it during lowering operations of the buoy apparatus. Additionally, the weight 17 is provided with any suitable hoisting line 19 for raising it again to the surface.

The buoy apparatus of FIGURE 1 is provided with suitable latching means, for example, in the form of spring-loaded latching dogs 22 which are pivoted in a manner to extend outwardly beyond the vertical wall of the buoy line housing 12 so as to latch in a cooperating shoulder 23 (FIGURE 2) formed on the inner wall of the container 24. Thus, when the buoy line housing 12 of the buoy apparatus of FIGURE 1 passes downwardly into the container 24 of FIGURE 2, the spring-loaded dogs 22 (FIGURE 1) are forced inwardly by the inner surface of the container 24 until they pass the shoulder 23 thereof, at which time the latching dogs 22 move outwardly underneath the shoulder and prevent the buoy apparatus from rising out of the container 24. The container 24 is preferably provided with a guide cone 25 around its open end for facilitating the entry of the buoy line housing 12 of FIGURE 1 thereinto. The spring-loaded latching dogs 22 may form part of a remotely controlled releasably lockdown assembly 26, positioned above the buoy line housing 12, which contains the necessary equipment and circuitry and power units for receiving preferably a sonic signal transmitted from a remote source, such as the barge on the surface of the water, so as to cause the latching dogs 22 to be retracted and allow the buoy apparatus to escape from the container 24.

Alternatively, instead of locating the mechanism for retracting the latching dogs in the lock-down assembly 26, other suitable means may be provided which are positioned on the container 24. For example, in FIGURE 2 the container 24 is shown as being provided an unlatching ring element 27 which is adapted to be raised and lowered within an annular groove 28 in the inner wall of the container 24, in any suitable manner. In the mechanism illustrated in FIGURE 2, a portion of the ring element 27 extends outside the container 24 and is connected through pivot pin 31 and piston arm 32 to a piston (not. shown) contained within a hydraulic cylinder 33 which is securely mounted, as by a bracket 34, to the outer wall of the container 24.

Hydraulic lines

36 and 37 leading to the cylinder 33 are in communication with a pressure source (not shown). Thus, by supplying pressure fluid through one line 36 or the other 37, the piston rod 32 can be moved up or down to actuate the unlatching ring element 27 which is arranged to move upwardly as far as the shoulder 23 and force latching dogs 22 (FIGURE 1) out of the annular groove 28 (FIGURE 2). In the event that the buoy apparatus and its container were being used on a wellhead installation positioned on the ocean floor, the

hydraulic pressure lines

36 and 37 could be arranged in a bundle together with the other power transmission lines leading from the wellhead installation. If desired, a single hydraulic line 37 may be employed to force the ring element 27 upwardly while compression springs 38; are used to force the ring element downwardly to its original position. While these springs 38 are shown as being uncovered, they would normally be covered in anunderwater installation or contained within the hydraulic cylinder. Preferably, both the releasable lock-down assembly 26 of FIGURE 1 and the unlatching ring element 27 of FIGURE 2 are provided on the same installation with the releasable lock-down assembly 26 serving as an auxiliary release in the event that the unlatching ring assembly 27 should fail.

Coiled within the buoy line housing 12 (FIGURE 1) is a suitable length of buoy line whose upper end is secured, as at 41, to the buoy line housing 12. The buoy line housing 12 has an opening in the bottom thereof through which the lower end 42 of the buoy line 40 may be pulled. Preferably the lower end of the buoy line housing 12 is open with a plurality of radially extending metal straps 43 extending horizontally and being of a strength sutficient to support the weight of the cable 40 and prevent it from dropping out of the open bottom of the housing 12. These straps are made of a corrodible metal which will corrode in a few hours or days in seawater after the buoy apparatus of FIGURE 1 has been installed in its container of FIGURE 2. When the metal straps 43 corrode the buoy line is left free to be released readily from the buoy line housing 12. The lower end 42 of the buoy line 40 is connected to an anchoring mechanism 44, as by an anchor-eye bolt 45. If it is desired to release an old buoy line 16 from its connection with the container 24, the anchor-eye bolt 45 is designed to fail under less tension than that which would break the buoy line 40. The buoy line 40 may be of any suitable material, either metal or a plastic such as nylon, with the tensile strength of the line depending upon future operations that are to be carried out at the wellhead installation through use of the line. Preferably a line that will support at least 5,000 lbs. is employed when other operations are to be carried out through use of this buoy line 40.

The anchoring mechanism 44 is provided with one or more locking dogs 46 which are preferably spring-loaded and adapted to move outwardly and engage a shoulder 47 formed in the bottom of the container 24. The anchoring mechanism 44 is releasably secured in a sliding manner on the lower end of the tubular element 13 in any suitable manner, as by means of very light collect fingers or spring elements 50 which frictionally engage the top of the anchoring mechanism 44 and prevent it from dropping downwardly when the buoyancy apparatus, as illustrated in FIGURE 1, is being lowered down along an old buoy line 16 into the container 24 of FIGURE 2. When the anchoring mechanism 44, on the buoy apparatus of FIG- URE l, enters the container 24 of FIGURE 2 and contacts the top of the old anchoring mechanism 44a which is still positioned therein, the weight of the buoy apparatus forces the old anchoring mechanism 44a downwardly and out the bottom of the container 24. At the same time the latching dogs 46 of the anchoring mechanism 44 latch beneath the shoulder 47 of the container 24 as illustrated in FIGURE 3. While this action is taking place the latching dogs 22 on the buoy line housing 12 are also seating beneath the shoulder 23 in the container 24.

With the new buoy apparatus positioned within the container 24 as shown in FIGURE 3, the old buoy line 16 is pulled free of the apparatus by applying a tension sufiicient to break the anchor-eye bolt 45a (FIGURE 2). Alternatively, the old buoy line 16 could be severed near the bottom thereof by lowering a wire line cutter of any suitable type well known to the art of oil well operations for cutting the buoy line 16. With the buoy in place, the lowering weight 17 (FIGURE 1) which was used to force the new buoy apparatus down through the water is pulled back to the surface. If desired, the buoyancy tank 11 may be provided with one or more radar reflectors 51 extending upwardly therefrom to aid in location of the buoy when radar is used on the surface vessels. The buoyancy tank 11 is designed to withstand a hydrostatic pressure of the ocean water at the desired depth and has enough positive buoyancy to lift the entire buoyancy apparatus and buoy line 40 to the surface. The positive buoyancy effect of the buoyancy tank 11 is also sufficient to pull the collect fingers 50 of the tubular element 13 out of the anchoring mechanism 44.

I claim as my invention:

1. A marine marker buoy assembly for marking an underwater installation, said assembly comprising a buoy apparatus base to which a buoy apparatus is adapted to be secured, said base adapted to be secured to an underwater installation, a buoy apparatus normally releasably secured to said base, said buoy apparatus comprising a buoyancy tank, a buoy line holder positioned below said tank, guide means secured to said tank, a buoy line adapted to be stored in said holder, the upper end of said buoy line being secured to said buoy apparatus, anchoring means connected to the lower end of said buoy line and releasably carried on the buoy apparatus for engaging said base and anchoring said buoy line thereto, and latching means for latching said buoy apparatus within said base, a portion of said latching means carried by said buoy apparatus and a cooperating portion carried by said base.

2. A marine marker buoy assembly for marking an underwater installation, said assembly comprising a buoy apparatus container having an opening in the top thereof for discharging a buoy apparatus therefrom, said container adapted to be secured to an underwater installation, a buoy apparatus normally releasably positioned Within said container, said buoy apparatus comprising a buoyancy tank, a buoy line housing positioned below said tank and having an opening in the bottom thereof for discharging a buoy line therefrom, guide means secured to said tank and said housing, a buoy line adapted to be stored in said housing, the upper end of said buoy line being secured to said buoy apparatus, anchoring means connected to the lower end of said buoy line and releasably carried on the buoy apparatus for engaging said container and anchoring said buoy line thereto, and latching means for latching said buoy apparatus within said container, a portion of said latching means carried by said buoy apparatus and a cooperating portion carried by said container.

3. A marine marker buoy assembly for marking an underwater installation, said assembly comprising a buoy apparatus container having an opening in the top thereof for discharging a buoy apparatus therefrom, said container adapted to be secured to an underwater installation, a buoy apparatus normally releasably positioned within said container, said buoy apparatus comprising a buoyancy tank, a buoy line housing positioned below said tank and having an opening in the bottom thereof for discharging a buoy line therefrom, a tubular guide element extending axially and vertically through and being secured to said tank and said housing, a buoy line adapted to be stored in said housing, the upper end of said buoy line being secured to said buoy apparatus, anchoring means connected to the lower end of said buoy line and releasably carried on the lower end of said tubular guide element for engaging said container anchoring said buoy line thereto, and latching means for latching said buoy apparatus within said container, 9. portion of said latching means carried by said buoy app-aratus and a cooperating portion carried by said container, one of said portions of said latching means including remotely-actuatable radially-extendible latching dogs, said container having recess means therein for engaging said latching dogs.

4. A marine marker buoy assembly for marking an underwater installation, said assembly comprising a buoy apparatus container having an. opening in the top thereof for discharging a buoy apparatus therefrom, guide cone means secured to said container around the top opening thereof for guiding a buoy apparatus thereinto, said container adapted to be secured to an underwater installation, a buoy apparatus normally releasably positioned within said container, said buoy apparatus comprising a buoyancy tank, a buoy line housing positioned below said tank and having an opening in the bottom thereof for discharging a buoy line therefrom, a tubular guide element extending axially and vertically through and being secured to said tank and said housing, a buoy line adapted to be stored in said housing, the upper end of said buoy line being secured to said buoy apparatus anchoring means connected to the lower end of said buoy line and releasably carried on the lower end of said tubular guide element for engaging said container anchoring said buoy line thereto, buoy line release means carried by buoy apparatus for disconnecting the lower end of the buoy line from said container, latching means for latching said buoy apparatus within said container, a portion of said latching means carried by said buoy apparatus and a cooperating portion carried by said container, one of said portions of said latching means including remotely-actuatable radially-extendible latching dogs.

5. A method of installing a releasable buoy in an underwater buoy container and anchoring a new buoy line thereto, said method comprising the steps of slidably engaging a buoy having a buoy line to a second buoy line extending upwardly through the water from a fixedly-positioned underwater buoy base, reducing the buoyancy of said buoy to a negative value, sliding said buoy and its line downwardly along said second buoy line and to said buoy base, releasably-latching said buoy and its line to said buoy base, anchoring one end of said buoy line to said buoy base, and subsequently providing said latched buoy with a positive buoyancy sufiicient to raise it and its buoy line to the surface when unlatched.

6. A method of installing a releasable buoy in an underwater buoy container and anchoring a new buoy line thereto, said method comprising the steps of slidably engaging a buoy and its buoy line to a second buoy line extending upwardly through the water from a fixedlypositioned underwater buoy container, weighting the buoy suificiently to give it a negative buoyancy, sliding said weighted buoy and its line downwardly along said second buoy line and into said buoy container, releasably-latching said buoy and its line within said buoy container anchoring one end of said buoy line to said buoy container, and subsequently removing the weight from said latched buoy.

7. A method of installing a releasable buoy in an underwater buoy container and anchoring a new buoy line thereto, said method comprising the steps of slidably engaging a buoy and its buoy line to a second buoy line extending upwardly through the water from a fixedly-positioned underwater buoy container, weighting the buoy sufiiciently to give it a negative buoyancy, sliding said weighted buoy and its line downwardly along said second buoy line and into said buoy container, releasably-latching said buoy and its line within said buoy container anchoring one end of said buoy line to said buoy container, removing said second buoy line from engagement With said container and subsequently removing the Weight from said latched buoy.

8. A marine marker buoy assembly for marking an underwater installation, said assembly comprising a buoy apparatus base adapted to be secured to an underwater installation, a buoy apparatus normally releasably secured to said base, a buoy line holder positioned below said buoy apparatus, saidbuoy apparatus comprising a buoyancy tank, a buoy line adapted to be stored in said holder, the upper end of said buoy line being secured to said buoy apparatus, anchoring means connected to the lower end of said buoy line for engaging said base and anchoring said buoy line thereto, and latching means for latching said buoy apparatus to said base, a portion of said latching means carried by said buoy apparatus and a cooperating portion carried by said base.

References Cited in the file of this patent UNITED STATES PATENTS