US2953904A - Submersible barge assembly - Google Patents

Description

Sept. 27, 1960 L. B. CHRlSTENSON SUBMERSIBLE BARGE ASSEMBLY 5 Sheets-Sheet 1 Filed April 5, 1958 Lowe B. C/W/Jzemmn flINVENT R. BY

L. B. CHRISTENSOYN SUBMERSIBLE BARGE ASSEMBLY I 5 Sheets-Sheetv 2 Filed April 3, 1958 INVENTOR.

Sept. 27, 1960 L. B. CHRISTENSON SUBMERSIBLE BARGE ASSEMBLY Filed April 3, 1958 sneets-sneet 5 3 E 31\|N\\ V E.

. INVENTOR.

A oyve B. C/7/VJ fensan ATTO/F/VE VJ Sept. 1950 L. B. CHRISTENSON 2,953,904

SUBMERSIBLE BARGE ASSEMBLY Filed April 3, 1958 5 Sheets-Sheet 4 Lowe B. C/wuze/van Sept. 27, 1960 L. B. CHRISTENSON 4 SUBMERSIBLE BARGE ASSEMBLY Filed April 3, 9 8 5 Sheets-Sheet 5 Lowe .5. (fir/J fer/Jon U i a es atefifo,"

2,953,904 SUBMERSIBLE BARGE ASSEMBLY Lowell B. Christensen, 7410 Thur-ow, Houston 17, Tex.

Filed Apr. 3, 1958, Ser. No. 726,225

7 Claims. (Cl. 61-465) This invention relates to a submersible barge assembly and more particularly to one in use with oflf-shor-e drilling of oil and gas wells.

With the advent of drilling oil and gas wells in water in off-shore locations numerous structures have been developed to support the equipment necessary to drill such wells. These structures are either fixed or movable with the fixed structure being erected on the location usually by driving pilings into the ocean floor. The movable structures are usually floated to the site of operation and then anchored in position by sinlsing various parts of the structure to the ocean floor and driving temporary pilings to serve as additional anchoring means. The fixed storm of structure has the obvious disadvantage of being immovable and the movable structures now in operation have various disadvantages including lack of stability during anchoring operations and initiating of the removal to a new location and ditficulty with proper 'submerging of various parts of the structure. It is to an improved type of movable structure that the present invention is directed.

It is a general object of the present invention to provide a submersible barge assembly supporting a work platform which assembly includes upper and lower hulls each of which may be lowered to and raised from the ocean rfloor as a unit on vertical columns.

Another object is to provide such an assembly including means preventing binding of the hulls on the columns during "vertical movement of the hulls.

Another object of the present invention is to provide a submersible barge assembly having upper and lower hulls each of which may be lowered to and raised from the ocean floor as a unit on columns with the upper hull carrying with it a bracing structure.

A further object is .to provide a submersible barge assembly having upper and lower hulls with vertical columns from the lower hull extending upwardly and freely slidable through the upper hull and vertical casings extending above the upper hull and having novel means to releasably secure the casings to the columns.

A' still further object of the present invention is to provide a submersible barge assembly including upper and lower hulls with the upper hull adapted to be used conveniently as under water storage for oil.

A still further object of the present invention is the provision of a submersible barge assembly having upper and lower hulls and vertical columns tiltably secured to the lower hull and extending slidably through the upper hull with said colurrms remaining vertical even though the ocean floor on which the lower hull rests may be slanted.

Other objects and advantages will be more apparent from the following description of preferred examples of the invention, given for the purpose of disclosure, taken in conjunction with the accompanying drawings, where like character references refer to like parts throughout the several views and where, p V v 'Figure 1 is an end view of the present invention with invention in position with the lower hull resting on the ocean floor,

Figure 3 is a view similar to Figure 2 illustrating the lowering or raising of the upper hull,

Figure 4 is a view similar to Figure 3 illustrating the structure latter the upper hull has been fully lowered,

Figure 5 is a side elevation illustnating the structure of the present invention with both hulls lowered and anchoring pilings in position,

Figure 6 is an end view of ture of Figure 5, V

Figure 7 is a schematic plan view of the upper hull,

Figure '8 is a schematic plan view ofthe lower hull,

Figure 9 is an enlarged fragmentary elevation of the upper end of a casing through which slidably extends a column with expansible gripping means to releasably grip the column,

Figure 10 is a partially schematic perspective view illustrating the novel relative movement control means for lowering and raising the two hulls, and

Figure 1 .1 is an enlarged fragmentary view of a modified form of connection of a column to the lower hull.

Referring now to the drawings, and particularly to Figure 5, there is illustrated the submersible barge assembly indicated generally by thenumeral 10 supporting aconventional work platform 12 on which are located various structures such .asliving quarters 14, work shops 16, adrilling platform 18,mud tanks 20 and the like. Thiswork platform 12 and the various structures on it are conventional, as such do not constitute the present invention, and no further description of them is necessary.

Referring to Figures 1 through 4, the submersible barge assembly It) includes anupper hull 20, alower hull 22, a plurality of spacedvertical columns 24 secured to thelower hull 22 and extending slidably upwardly through the upper hull 2i andcasings 26 secured to the upper hull 2d. Thecolumns 24 are releasably secured to thework platform 12 and thecasings 26 are rigidly interconnected and held in vertical position by a bracing structure 28 for-med by a network of structural members. The entire structure illustrated in Figures 1 through 4 when being moved is supported by a buoyancy of theupper hull 20 with thelower hull 22 having only sufficient buoyancy in water to support itself.

As illustrated in Figure 8 thelower hull 22 includes a plurality of compartments of which thecompartments 30 around the periphery are open to the sea and filled with Water at all times. To give the desired negative or positive buoyancy there are provided centrally located water tight and individually controlledbuoyancy compartments 32 connected by a system of conduits through individually controlled valves 36 to apump 38 in a pumproom 40. Theindividual compartments 32 are vented, preferably through thecolumns 24, and thepump 38 has a connection, not shown, to sea water. Thepump 38 is electrically controlled and the valves '36 are hydraulically controlled from thework platform 12 by any conventional system. Adrilling slot 39 is formed at one end of thelower hull 22 through whichslot 39 drilling is performed.

As illustrated in Figure 7, theupper hull 20 is subthe right end of the strucstantially co-extensive with thelower hull 22 and includes in a pumproom 50 so that eachcompartment 42 may As illustrated in Figures 1 through 4, thelower hull 22 is moved vertically relative to theupper hull 20 by sliding movement of thehollow columns 24 through thehollow casings 26 and once thelower hull 22 is in position on the ocean floor theupper hull 20 is moved vertically with respect to thelower hull 22 by a sliding movement of thecasings 26 relative to thecolumns 24. A loose fit (Figure 9) giving considerable clearance between thehollow columns 24 and thecasings 26 is provided to prevent undue friction and bending during such movement. However, this loose fit is undesirable when the upper andlower hulls 20 and 24 respectively are not being moved relative to each other as wave action will cause undesirable vibration and movement. To prevent such undesirable movement the upper end of each of thecasings 26 is provided with an annular metal housing 54 containing an inflatablepneumatic ring 56 with thepneumatic ring 56 being connected to an air supply through the lead 58. Any conventional source of air pressure located on thework platform 12 may be connected to the leads 58 to supply air pressure to and drain it from thepneumatic rings 6. Inflation of thepneumatic rings 56 securely locks the upper end of thecasings 26 to thecolumns 24 and deflation of thepneumatic rings 56 permits free sliding movement between thecolumns 24 andcasings 26.

To prevent movement between the lower surface of theupper hull 20 and the upper surface of thelower hull 22 there is provided on thecolumns 24 immediately above the lower hull 22 (Figures 1-4) an upwardly directed coneshaped projection 60 and in the lower surface of the upper hull 20 a mating cone shaped recess 62 which a mating projections and recesses are engaged when the upper and lower hulls are in close proximity as illustrated in Figures 1 and 4 and prevent any horizontal movement between thecolumns 24 andcasings 26 in the vicinity of theseprojections 60. Theseprojections 60 are preferably spaced slightly above the upper surface of thelower hull 22 to prevent contact between the upper andlower hulls 20 and 22 when the structure is either floating as illustrated in Figure 1 or when both hulls are submerged as illustrated in Figure 4. This space between the hulls prevents suction from developing when initiating vertical movement of one hull in relation to the other and prevents debris which might collect on the upper surface of thelower hull 22 from damaging either of the hulls.

Because the upper andlower hulls 20 and 22 are moved vertically in relation to one another all thecolumns 24 simultaneously move through all thecasings 26 and any tilting of one hull relative to the other during such movement will cause binding between thecolumns 24 and thecasings 26 resulting in jerky and dangerous movement and difiiculty in control of the movement. The relativemovement control system 63 to prevent such tilting is best illustrated in Figures 1, 5, and 10.

Secured at the top of a plurality ofspaced columns 24, preferably four with two at each end of thelower hull 22, areshock absorbers 64, 66, 68, and '70 respectively, which may be of any conventional type and no detailed description of them is necessary. Secured to thecasings 26 on each of thesecolumns 24 adjacent the upper surface of theupper barge 20 are tootheddouble pulleys 72, 74, 76,

and 78 respectively forming rotatable guide assemblies. From the shock absorber 64 achain 80 forming a flexible connecting element passes vertically downwardly, under one side of thedouble pulley 72, across to and over one side of thedouble pulley 74, and downwardly through theupper hull 20 where it is secured to an opposite corner of thelower hull 22 by abracket 82. Similarly, achain 84 brake rod extends downwardly from theshock absorber 66 under the other side of thedouble pulley 74, across and over the other side of thedouble pulley 72, and downwardly through theupper hull 20 where it is connected to an opposite corner of thelower hull 22 at thebracket 86. At the opposite end of the hulls achain 88 passes downwardly from theshock absorber 68, under one side of thedouble pulley 76, over one side of thedouble pulley 78 and downwardly through theupper hull 20 where it is connected by the bracket to thelower hull 22. Likewise, achain 92 extends downwardly from theshock absorber 70 under the other side of thedouble pulley 78, over the other side of thedouble pulley 76, and through theupper hull 20 where it is connected to thelower hull 22 by thebracket 94. As thus constructed, when thecolumn 24 to whichshock absorber 64 is connected moves vertically theopposite corner 82 at the same end of thelower hull 22 must move vertically at the same rate because they are connected by thechain 80. It is noted that the corner at thebracket 82 moves downwardly at the same rate ascolumn 24 to which theshock absorber 64 is attached because the portion of thechain 80 leading from thebracket 82 to thedouble pulley 74 and the portion ofchain 80 leading from theshock absorber 64 to thedouble pulley 72 are parallel to each other. This same control also results from the connection of the upper end of thecolumn 24 to which theshock absorber 66 is connected because the portion of thechain 84 leading from theshock absorber 66 to thedouble pulley 74 is parallel to the portion of thechain 84 leading from thebracket 86 at the opposite'corner on the same end of thelower hull 22 to the double.pulley 72. A similar controlled movement is provided at the other end of thelower hull 22 by the chains and double pulleys located there. Because thedouble pulleys 72, 74, 76 and 78 are connected to theupper hull 20 through the connections of these double pulleys to thecasings 26, all vertical movement of theupper hull 20 in relation to thelower hull 22 is likewise controlled.

To force the opposite ends of the bulls to move simultaneously, at least one of thedouble pulleys 72 or 74 at one end of theupper hull 20 is connected to at least one of-thedouble pulleys 76 or 78 at the other end of theupper hull 20 and preferably, as illustrated in Figure 10, each of the double pulleys at one end of theupper hull 20 is connected to one of the double pulleys at the other end by aconnector rod 96 secured between thedouble pulleys 72 and 76 and aconnector rod 98 secured between thedouble pulleys 74 and 78 so that thedouble pulleys 72 and 76 must rotate at the same speed and likewisedouble pulleys 74 and 78 must rotate at the same speed. Because either of thechains 80 or 84 force thepulleys 72 and 74 to rotate at the same speed and either of thechains 88 or 92 force thepulleys 76 and 78 also to rotate at the same speed these connectingrods 96 and 98 require all four double pulleys to rotate at the same speed and cause uniform vertical movement of all four corners of the upper andlower hulls 20 and 22.

To control the speed of vertical movement of the upper andlower hulls 20 and 22 abrake 100 is provided on the connectingbar 98 and is controlled by thetelescoping 102 rising vertically to abrake wheel 104 situated on the work platform 12 (Figures 5 and 10).

In operation, when the structure is to be moved to a location it is in the position illustrated in Figure 1 with thevarious compartments 42 in theupper hull 20 being emptied of water to give sufiicient positive buoyancy to float the entire structure above theupper hull 20. Thelower hull 22 is raised against theupper hull 20 and given sutficient positive buoyancy in water by the buoyancy compartments 32 to float thelower hull 22 but not enough positive buoyancy to give any appreciable lift to theupper hull 20. The provision of theopen compartments 30 in thelower hull 22 prevents a dangerous lifting elfect from being given by thelower hull 22 and adds to the stability of the structure. When in the position illustrated in Figure 1 the mating projections and recesses 60 and 62 respectively adjacent thelower hull 22 and he lower surface of the upper hulll20 are engaged preventing horizontal movement between the two bulls and the pneumatic rings {56 at the upper end of the casings '26 are inflated tightly gripping thecolumns 24 prevent ng any vibration at the upper ends of thecasings 26. 7

Upon reaching the desired location the pneumatic rings 5 6are deflated, thebrake 100 on therod 98 is released, and the ballast compartments 32 in thelower hull 22 are flooded sufliciently to give the lower hull 22 a negative buoyancy causing it to descend carrying with it and being guided by thecolumns 24 moving downwardly through thework platform 12 and thecasings 26. The relativemovement control system 63 causes the four opposite corners of thelower hull 22 to move downwardly at thesame rate of speed with the speed of descent being"'controlled by thebrake 100. Because the four opposite corners of thelower hull 22 move downwardly evenly there is no binding between thecolumns 24 and thecasings 26. Upon thelower hull 22 reaching the ocean floor as illustrated in Figure 2 the ballast compartments 32 may be completely flooded to give additional anchoring effect.

After thelower hull 22 is seated on the ocean floor and while theupper hull 20 is ,still supporting thework platform 12, thework platform 12 is secured to thecolumns 24 and supported thereby so there is no further relative, movement between thecolumns 24 and the work platform 12'. This may be done in any convenient mannersuch as by the slotted locking sleeves 106 (Figure 5) secured to thework platform 12 and though which extendthecolumns 24.Flanges 108 on each slotted locking sleeve 106 are pulled together by bolts 110 binding the slotted locking sleeve 106 tightly to thecolumns 24.

After thecolumns 24 are secured to thework platform 12 the various buoyancy compartments 42 of theupper hull 20 are flooded sufficiently to give the upper hull 20 a negative buoyancy whereupon theupper hull 20, thecasings 26, and the bracing structure 28 are lowered as a unit down thecolumns 24 with all four corners of the upper,hull 20 moving downwardly at an even rate through the operation of the relativemovement control system 63 previously described. Upon theupper hull 20 reaching its lowermost position as illustrated in Figure 4 the mating projections and recesses 60 and 62 are engaged preventing horizontal movement between the upper andlower hulls 20 and 22 and the pneumatic rings 56 at the upper ends of thecasings 26 are expanded gripping the upper ends of thecasings 26 to thecolumns 24 so that horizontal movement of theupper hull 20, thecasings 26, and the bracing structure 28 relative to thecolumns 24 and thelower hull 22 is prevented. After the upper hull is in its lowermost position it also may be completely flooded to give additional anchoring eifect.

If desired, after both the upper andlower hulls 20 and 22 are on the ocean floor additional stability to the entire structure may be given by drivingpilings 112 downwardly through the hollow columns 24 (Figures 5 and 6) into the ocean floor.

When it is desired to move the structure to a new location thepilings 112 are removed, the pneumatic rings 56 at the upper ends of thecasings 26 are deflated, and suflicient positive buoyancy is given to theupper hull 20 by removing water from the buoyancy compartments 42 to cause theupper hull 20 to rise. By action of the relativemovement control system 63 all four corners of theupper hull 20 will rise evenly preventing any binding between thecolumns 24 and thecasings 26 and the speed of the upward movement of theupper hull 20 is controlled by both its buoyancy and thebrake 100. When theupper hull 20 has reached its uppermost position as illustrated in Figure 2 all its buoyancy compartments 42 are emptied, the slotted locking sleeves 106"ar e loosened so thatthecolumns 24 may slide through them, and the ballast compartments 32 of thelower hull 22 are pumped out sufliciently to give it a positive buoyancy causing it to rise. Because the compartments 30' of thelower hull 22 are open to water and cannot be emptied a limit is placed upon the amount of positive buoyancy which can be given to thelower hull 22 with such limited positive'buoyancy and the brake limiting the rate of rise of thelower hull 22.Thelower hull 22 andcolumns 24 will rise because the entire structure is then supported by theupper hull 20. The relativemovement control system 63 prevents canting of thelower hull 22 relative to theupper hull 20 thus preventing binding between thecasings 26 andcolumns 24. Uponthe'lower hull 22 reaching its uppermost position as illustrated in'Figure' 1 themating projections 60 and 62 are re-engaged and the pneumatic rings 56 are again inflated.

Referring now to Figure 11 there is illustrated a modification in the manner of connection of the lower ends of thecolumns 24 tothe lower hull 22- by providing a tiltable connection so that if the ocean floor is slanted the lower hull 22upon seating may slant and seat firmly on the ocean floor with thecolumns 24 still rising vertically. At the lower end of eachcolumn 24 in this modification is aflange 114 in the shape of a spherical segment resting on a mating concave seat 116 secured to the upper surface of thelower hull 22. An overturned ear 118 surrounds the lower end of thecolumns 24 above thespherical flange 114 and allows limited movement oft-hespherical flange 114 with respect to the mating seat 11 6 but prevents the lower end of thecolumn 24 from being separated fromthelower hull 22. 'As thus constructedthe lower hull may tilt relative to the verticalv position of thecolumns 24 allowing thelower hull 22 to conform to a slanting ocean floor.

To grip the lowersurface of theupper hull 20 to thecolumns 24 in this modification when theupper hull 20 is in its lowermost position there is provided at the lower surface of the upper hull 20 apneumatic ring 120 which is in all respects identical to thepneumatic ring 56 at" the upper ends of thecasings 26. To space the upper hull 20' above the lower hull 22 a plurality of wooden;timbers 122 may be secured to the upper surface of thelower hull 22.

In operation of the modification illustrated in Figure 11, the upper and lower bulls are raised and lowered identically to the operation previously described except that thepneumatic ring 120 serves to hold the lower surface of theupper hull 22 securely around thecolumns 24 rather than the mating projections and recesses 60 and 62. When thelower hull 22 is seated on the ocean floor it will confrom to a tilt in the ocean floor without tilting thecolumns 24 and all other structure above thelower hull 22.

Storage of oil at the site of an off-shore drilling structure is a problem that has in the past sought to be overcome by under water storage of oil in submerged pontoons of off-shore drilling structures. The submersible barge assembly of the present invention is particularly adapted for such purpose in that theupper hull 20 may be used for under water storage of oil when theupper hull 20 is in its lowermost position by merely displacing the water in the buoyancy compartments 42 with oil through conventional lines and pumps (not shown) and by displacing the oil with water when it is desired to withdraw the oil from theupper hull 20. In such storage of oil it is necessary that the container be periodically cleaned. Because theupper hull 20 may conveniently be raised for cleaning while the work platform is firmly anchored and braced the present invention provides an excellent means for oil storage.

The present invention, therefore, is well suited to carry out the objects and attain the advantages mentioned as well as others inherent'therein. Changes in details and rearrangements of parts will suggest themselves to those skilled in the art and accordingly it is desired to be limited only by the spirit of the invention as defined by the scope of the appended claims.

What is claimed is: i

1. In a submersible barge assembly the improvement comprising, an upper hull having a positive buoyancy in water; a lower hull below the upper hull, said lower hull having a negative buoyancy in water; at least two spaced vertical columns secured to the lower hull and extending upwardly slidably through the upper hull; means to releasably secure said columns to the upper hull; at least four guide assemblies carried by the upper hull, at least two of which guide assemblies are rotatable, a first flexible connecting element connected to'an upper portion of one of said columns and to the lower hull at a point spaced from said one column, said first flexible connecting element engaging one rotatable guide assembly and one other guide assembly, a second flexible connecting element connected to an upper portion of another said column and to the lower hull at a point spaced from said other column, said second flexible connecting element engaging the other rotatable guide assembly and another guide assembly, and connecting means connecting said rotatable guide assemblies together so constructed and arranged that the rotatable guide assemblies rotate at the same speed, in each said flexible connecting element the portion leading from the colunm and the portion leading from the lower hull being parallel to each other.

2. The invention ofclaim 1 wherein the rotatable guide assemblies include toothed elements and the flexible connecting elements include links engaging said toothed elements.

3. The invention ofclaim 1 including brake means operable from above the upper hull and associated with said rotatable guide assemblies whereby rotation of said rotatable guide assemblies may be stopped.

4. The invention ofclaim 1 wherein the connecting means is rigid.

5. The invention ofclaim 1 including at least one buoyancy compartment carried by the upper hull and buoyancy control means associated with the buoyancy compartment in the upper hull adapted to control its buoyancy in water.

7 6. In a submersible barge assembly'the improvement comprising, an upper hull having a positive buoyancyin water; a lower hull below upper 'hull, said lower,

means releasably securing the columns to the upper hull;

at least four double rotatable guide assemblies carried by the upper hull; four flexible connecting elements, one each of said connecting elements connected to an upper portion of one of said columns and to the lower hull at a point spaced from said column, two each of said flexible connecting elements passing through and engaging the first and second of said rotatable guide assemblies, the other two of said flexible connecting elements engaging the second and third of said rotatable guide assemblies, in each said flexible connecting element the portion leading from said column and the portion leading from the lower hull connection being parallel to each other; and connecting means connecting said first and third guide assemblies together so constructed and arranged that said first and third guide assemblies rotate at the same speed. 7. The invention ofclaim 6 including brake means operable from above the upper hull and associated with said rotatable guide assemblies whereby rotation of said double rotatable guide assemblies may be stopped.

References Cited in the file of this patent UNITED STATES PATENTS

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