US2940266A - Method of constructing an offshore well drilling island - Google Patents

Description

June 14, 1960 V. SMITH METHOD OF CONSTRUCTING AN OFFSHORE WELL DRILLING ISLAND Filed July 30, 1956 3 SheetsSheet 1 INVENTOR. VfzeA/f SM/T/V BY $0M? V. SMITH METHOD OF CONSTRUCTING AN OFFSHORE WELL DRILLING ISLAND Filed July 30, 1956 3 Sheets-Sheet 2 a 0. W M M M m W "H MW .1 -M 5w 0 m. Y B

June 14, 1960 v. SMITH 2,940,266

METHOD OF CONSTRUCTING AN OFFSHORE WELL DRILLING ISLAND Filed July 30, 1956 3 Sheets-Sheet 3 BY fa/r4 United States l atent O METHOD OF CONSTRUCTING AN OFFSHORE WELL DRILLING ISLAND Verne Smith, Corona Del Mar, Ca1if., assignor to Shamrock Drilling Co., Los Angeles, Calif.

Filed July 30, 1956, Ser. No. 600,906

5 Claims. (Cl. 61-465) This invention relates to a method and apparatus for the connection joint 13. Rubber pads 35 may be provided at the joint if desired.

Support structure 36 carried on the upper member 11 is provided with a circular track having conventional rails 37. A carriage 38 is provided with wheels which roll on this track and with a bearing 39 which is positioned on the vertical axis of the island 10. A

drilling and producing oil, gas or other wells in an ofi shore marine location. This invention finds particular usefulness in connection with a drilling and production island structure which is portable to the extent that it can be floated to the desired site, rested on the bottom and used as a supporting structure for drilling and producing oil Wells, the entire device being movable to float to a new location if desired. i i

Among the objects of the present invention are to provide method and apparatus for constructing a support for a well drilling rig in a marine location and for producing oil or gas from wells drilled from such island. Another object is to provide method and apparatus for constructing a removable island of this type and wherein parts thereof may be separately floated to the drilling site. Another object is to provide a drilling island which is relatively inexpensive to manufacture and erect, which is inherently stable in resisting wind, wave and tide action and which may be used to drill a number of directional holes from the single location. advantages will appear hereinafter.

In the drawings:

Figure 1 is a side elevation showing a preferred embodiment of my invention.

Figure 2 is a fragmentary top plan view thereof, certain parts being omitted for clarity of illustration.

Figures 3, 4, 5, 6 and 7 show steps in the method'of erection of the device.

Figure 8 is a sectional elevation showing a modification.

Figure 9 is a sectional plan view taken substantially on lines 9-9 as shown in Figure 8.

Referring to Figures 1-7 of the drawings, a drilling island generally designated 10 includes an upper member 11 and a bottom member 12 connected at the joint 13 by a plurality of removable fastener elements 14. The bottom member 12 comprises concentric frusto conical walls 15 and 16 connected by partitions 17 forming buoyant chambers 18. The lower ends 19 and 29 of the walls may be cylindrical and these cylindrical portions are joined by an annular bottom wall 21. The upper ends of the walls 15 and- 16 likewise may be cylindrical as indicated at 2 2 and 23 and the connecting annular top wall 24 forms one side of the joint COD: nection 13. v a

A central vertical guide tube 25 is mounted within the lower member 12 and is connected to the wall '16 by-rneans of suitable beams..26.and 27 and by angle braces 28.. These .beamsand braces preferably extend radially with respect to the central tube 25.

The upper member 11 is preferably formed of concentric walls 30 and 31 defining an annular space 32 between them. This annular space is divided by partitions 33 to form buoyant chambers. At the lower ends of the walls 30 and 31 there is provided an annular floor 34 which is shaped to cooperate with the wall 24 to form Other related objects and drill rig assembly generally designated 40 is mounted on this carriage 38.

The drill rig assembly 40 includes a mast 41, drilling and hoisting machinery 42 and engines 43. The carriage 38 may be moved to bring the mast 40 and drilling machinery into position for drilling a hole through any one of the vertical conductor pipes 44 provided in the upper member 11. The vertical axes of these conductor pipes are spaced topass between the beams 26 and 27 and inclined braces 28 on the lower member 12.

In constructing the drilling island in accordance with my method, the drill site 50 on the ocean floor may be levelled or smoothed, if desired, as shown in Figure 5. A vertical cluster of piles 51 is then driven into the ocean fioor at the center of the Well site by conventional means suchas, for example, by pile driving apparatus mounted 'on a floating barge (not shown). The lower member 12 is then floated to the drill site, the compartments 18 being filled with compressed air. A vertical tubular guide or bar 52 is telescoped over the upper end of the pile cluster 51 after the tubular guide 52 has been inserted into the central tube 25 on the member 12.

Pull down cables 53 are attached to the member 12 and pass under pulleys 54 connected to the weight blocks 55 resting on the ocean floor. Each of the cables is connected to one or more buoyant tanks 49 so that the tension applied to the cables by the buoyant tanks serves to apply downward force to the member 12. Additional guy wires 56 are used to maintain the member 12 against lateral movement. The parts are then in the position shown in Figure 4.

The buoyancy tanks 18 are then flooded to cause the member 12 to descend and rest on the ocean floor. The descent is accomplished with the tubular guide 52 and cluster of piles 51 serving to prevent any sub-.

stantial tilting of the lower member 12 as it descends toward the ocean floor. The member comes torest with the annular floor surface 21 resting on the ocean floor...

The device is then in the position shown inFigure 5;

Sand or other material heavier than sea water is then.

pumped into the interior of the lower member 12 to fill the entire space within the inner Wall 16. Piles 48.'

are then driven through vertical openings 57 provided around the periphery of the member 12. The cables 53 and 56 are then removed. The device is then in the. position shown in Figure 6. Rock and rip-rap 57- maythenv be placed around the outer periphery of the lowerv end of the member 12 as shown in Figure 7. The lower member 12 is then firmly anchored inplace-with its upper end substantially below the water line 58. -I't will be understood that although I have referred to the .f body of water as the ocean, it is intended that the device. may be usedin any body of water and not necessarily the open sea.

It will be observed that'the rocks and riprap lie against the inclined outer wall 15 and thereby et fectivelymember 12 and the two members are connected together by the fastener elements 14 to function as a single integral unit. The upper member then extends substantially above the waterlevel '58 so that the machinery on the decks 59 and 60 are positioned above the maximum height of the waves. Thedrill rig assembly 40 maybe in position on the upper member when it is floated out to'sea and as soon as the membels 11 and 12 have been connected solidly together, *the drilling operations may commence. The mud pits, mud pumps and associated equipment may be located on the deck 59. The carriage 38 is moved on the rails 37 to a position to bring the drill string (not shown) into alignment with one of the conductor pipes 44 and the well is directionally drilled through the conductor pipe in the conventional manner. Additional wells may be directionally drilled at each of the other conductor pipes so thata large number of wells may be drilled from the single island. The well: may be completed and produced in conventional manners. Pumpingjacks (not shown) may be mounted on the upper deck Stitor each of the wells. If the island is to be used for production, it is desirable to fill the chambers 18 with concrete so that the island becomes a Y permanent installation.

If oil is not found in commercial quantities, the island 'may be'refloated and moved to a new site. I'his is accomplished'by removing the rocks and rip-rap 57am by pumping'out the sand within the inner wall16, The entire island may then be refloated as a unit after 'the' piles 51 and 56 have been cut by divers. V

The island '10 also may be Iefloated andmoved to 'a new location in two'sections' 'In this case,'the remov level. The joint 13 is omitted. In all other respects the construction and operation are the same as that previously described. The member 10a isiloated to the drill site and installed on bottom using the same series ofsteps as described above in connection with the lower member 12. 7

Having fully described my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

Iclaim:

l. A method of constructing a well drilling or production island in a marine location comprising the steps of: installingcentral vertical piling on the ocean floor terminating below the water level, floating a member into position over the piling so that a guide elementon the 'member' is aligned with the piling, placing a guide bar having a tubular portion through the guide element and over thetop' of the piling to form an extension thereof,

and loweringsaid member so that the guide element thereof telescopes over said guide bar and piling until the lower end, of said member rests on the ocean floor.

a 2 'A inethod of constructing a well drillingor production island in a marine location comprising the steps of;

I installing central vertical piling on the ocean floor terminating below the water level, floating a member into position over the piling so that-a single central guide element on the member is aligned with the piling, extending a guide bar having a tubular portion through the guide element and over the top of the piling to form an extension thereof, and lowering said member so that the guide element thereof telescopes over said guide bar and piling until the lower' end of said me'mber rests on the ocean floor. I H

3. A method oiconstructinga well drilling or production island in a marine location comprising the steps of: installing vertical piling on ;the ocean floor terminating below the water level, floating a lower member into position over the piling so that a guide element on the member is aligned with the piling, placing a guide bar having a tubular portion through the guide element and over the top of the piling to form an extension thereof, lowering said lowermemberso that the guide element thereof telescopes over said guide bar anclpiling until the lower end of said member rests on the ocean floor, removing the guide bar, floating an I'upper member into posin'on above the lower membenrandflowering said upper member to rest on said lower member so that the upper portion-of said upper member extends above the water level.

" 4; A method'of constructing a well drilling or production island in a marine location" comprising the steps of:

installing centralverticalpiling on the ocean floor terminating below'the water level, .floating a-lower member an extension .thereofl lowering said lower member so that the guide element thereof telescopes over said guide bar and piling 'until the lower end of. said member rests on the ocean floor, removing the guide bar, floating an upper member into position above the lower member,

and lowering said upper member to rest on said lower member so that the upper portion of said upper member extends above the water level.

'5. A method of constructing awell drilling or produc' tion island in a marine. location comprising thesteps of:

' installing central verticalpiling on the ocean floor terminating below the water level, floating a memberinto position over the piling so that aguide element on the member is aligned with the piling, extending aguide bar having a tubular portion through the guide element and over the top of the piling to form an extension thereof, lowering said member so that the guide element thereof telescopes over the guidebar and piling until the lower end of said member rests on the ocean floor, filling the interior .of the member with material heavier than water, and driving piles into the ocean floor at intervals around the periphery of the member.

References Cited in the file of thiszpatent UNITED STATES PATENTS.

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