US3190358A

US3190358A - Offshore well drilling apparatus

Info

Publication number: US3190358A
Application number: US308267A
Authority: US
Inventors: Glenn D Johnson; Bruce J Watkins
Original assignee: Shell Oil Co
Current assignee: Shell USA Inc
Priority date: 1963-09-11
Filing date: 1963-09-11
Publication date: 1965-06-22
Anticipated expiration: 1982-06-22

Description

June 22, 1965 Filed Sept. 11, 1963 G. D. JOHNSON ETAL OFFSHORE WELL DRILLING APPARATUS 2 Sheets-Sheet 1 FIG- 2 INVENTORS.

GLENN D. JOHNSON BRUCE J. WATKINS THEIR AGENT June 22, 1965 a. D. JOHNSON ETAL 3,190,353

OFFSHORE WELL DRILLING APPARATUS 2 Sheets-Sheet 2 Filed Sept. 11, 1963 FIG. 4

FIG.

INVENTORSI GLENN o. JOHNSON BRUCE J. WATKINS BY: 4.1M.

THEIR AGENT United States Patent "ice 3,190,358 OFFSHORE WELL DRELLING APPARATUS Glenn D. Johnson, Downey, and Bruce J. Watkins, Palos Verdes Estates, CalitZ, assignors to Shell Gil Company, New York, N .Y., a corporation of Delaware Filed Sept. 11, 1963, Eer. No. Sit-3,267 6 Claims. (Ci. 166-665) This invention relates to the drilling of oil and gas wells, and pertains more particularly to a method and apparatus for drilling offshore wells wherein the wellhead assembly is positioned on the ocean floor or a considerable distance under the surface of a body of water.

During recent years the continued search for oil has resulted in developing methods and apparatus for drilling underwater wells at locations where the Water may range from 100 to 1500 feet or more in depth. In these locations it is customary to position the wellhead at a considerable distance below the surface of the water, preferably on the ocean floor, so that it is not a hazard to the navigation of ships in the area. During well drilling operations it is often necessary to suspend two or more concentric strings of pipe casing or tubing from a drilling structure or vessel on the ocean surface with the pipe and tubing extending down into the well drilled in the ocean floor. A problem arises in providing the necessary pipe engaging and pipe supporting apparatus on the crowded operating floor of a drill rig in order to safely and adequately temporarily suspend multiple concentric strings .of pipe.

A primary object of the present invention is to provide offshore well drilling apparatus whereby multiple concentric strings of pipe extending from an underwater Well to a point above the surface of the ocean may be individually engaged and supported in a temporary manner.

A further object of the present invention is to provide a drilling vessel having multiple operating decks provided with apparatus for suspending each of a pair of concentric pipe strings from a separate operating deck of the vessel.

Another object of the present invention is to provide a drilling vessel with suitable pipe supporting apparatus whereby a string of easing may be suspended from one deck and extend into an underwater well while a drill string extends from a second deck through the casing and in the well.

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

FIGURE 1 is a diagrammatic view illustrating a floating drilling vessel position over a drilling location while supporting concentric strings of pipe therefrom;

FIGURE 2 is a longitudinal fragmental view diagrammatically illustrating another arrangement of suspending concentric pipe strings from the vessel illustrated in FIGURE 1;

FIGURE 3 is a fragmental view taken in longitudinal cross section illustrating two forms of pipe supporting equipment adapted to be used on the drilling vessel of FIGURE 1;

FIGURE 4 is a view taken in longitudinal cross section illustrating the lower pipe support on the auxiliarly deck of FIGURE 3 when raised to its vertical non-operative position; and

3,19%,358 Patented June 22, 1955 FIGURE 5 is a plan view of the pipe support structures on the lower or auxiliary deck of the vessel as shown in FiGURE 3.

Referring to FIGURE 1 of the drawing, an offshore structure for carrying out well drilling, completion and workover operations is shown. A drilling barge, vessel, or platform 1-1 of any suitable floating or floatable type is illustrated as floating on the surface of a body of water 12 and fixedly positioned over a preselected drilling location by being anchored to the ocean floor by

anchor lines

14 and 15 running to anchors (not shown). Equipment of this type may be used when carrying on well drilling operations in water varying from about feet to 1500 feet or more. The drilling vessel is equipped with a suitable derrick 16 containing a fall line system, including a travelling block 17, a hoist 18, a drilling swivel and/ or an elevator 19. The barge 11 is also provided with other auxiliary equipment neede during the drilling of the well, such for example as a rotary table 2% positioned on the operating deck 21, a hinged slip-and-spider assembly 22 positioned on the lower deck 23, etc. The elevator 19 is normally provided for suspending therefrom, during certain of the drilling operations, a drill string 24 or the kelly section at the top of the drill string while the slip-and-spider assembly 22 is adapted to secure fixedly a string of pipe, for example, a string of surface casing 25 against a vertical movement relative to the vessel 11.

During the actual drilling operations during which the kelly at the upper end of the drill string 24 is positioned in and rotated by the master bushing 26 in the rotary table Zii, it is to be understood that the kelly and rotary table could be replaced by a power swivel (not shown) in a manner well known to the art. The derrick 16 is positioned over a drilling slot, or well 26, which extends vertically through the vessel in a conventional manner. When using the equipment of the present invention, the slot 25 in the barge 11 may be either centrally located or extending from one edge. However, drilling operations may be carried out over the side of the barge without using a slot. It is also to be understood that in some areas the apparatus and method of the present invention may be utilized when operating from either a permanently fixed platform, or a temporarily fixed and normally iloatable platform. However, for purposes of illustration, the present invention will be described with regard to its use when drilling and completing a well from a floating barge which is preferably anchored but not necessarily so. In many drilling operations, the floating vessel may be maintained in a rela tively fixed position on the surface of the ocean by means of two or more outboard motors or other marine propulsion units arranged to act in our position.

The operating deck 21 of the offshore structures provided with a vertical opening 27 While the lower or auxiliary deck 23 is provided with a second vertical opening 28. Both the first and

second openings

27 and 28, respectively, are in vertical axially alignment. The operating deck 21 may also be provided with support beams 30 and 31 on opposite sides of the first opening 27 for supporting the rotary table 2%) thereon. If desired, the high beams 30 and 31 may be removably secured to the deck 21 so as to give a larger opening through the deck when lowering large equipment down to the underwater wellhead. Preferably, the spacing between the operating deck 21 and the auxiliary deck 23 is substantially equal to a normal length of pipe, say 20 feet, used to make up a drill string 24. Thus, the elevator 19 may be able to engage and suspend the upper end of the pipe section while the lower tool joint was being made up or broken on the auxiliary deck level.

The pipe-engaging and supporting apparatus used on the auxiliary deck 23 in supporting the pipe string 25 is preferably'a slip-and-spider assembly 22 of any conventional design; The slips32iare wedge shaped elements having handles 34'to facilitate Wrapping them aroundthe pipe 25 and inserting them into the hinged casing spider 22. The spider isprovided with. suitable handles 35 whereby it may be pulled apart along joint 36; When not in usethe casing spider 22 may be openedta nd pulled to one side. of theopening 28 through the auxiliary deck 23 by sliding it along the deck or in any other suitable manner, as willbe described hereinbelow. One suitable type of a casing spider is manufactured by the Baash- Ross Tool Company of .Houston', Texas, and is described in the Composite Catalog'of Oil Field Equipment and 4 suitable manner as by ticing it back with a rope 53 connected to a ring 54. V

'In moving the casing spider 22 and its platform 44 out of the way when a pipe string was extending down through the opening in the auxiliary deck 23 of the vessel, the lock pin 42 (FIGURE 5) would be pulled up and the two halves of the casing spider 22 opened after the slips had been removed therefrom. The two halves of the casing spider 22 would be pulled back until they were stopped by

locks

55 and 56 welded to the top of the platform 44. The platform 44 wouldthen be raised to its verticalpositionas shown in FIGURE 4 with the casing spider resting against the

blocks

55 and 56. I I

While the normal pipe engaging andsupportingmeans for use on the operating deck 21 would comprise slips 38 being used in conjunction with the rotary table 20 as described with regard to FIGURE 2, if desired, the rotary table 20 maybe removed and substituted for. a second casing spider diagrammatically represented by element 58 assurroundinglthe. pipe string .24 extending .up through theopening 2'7. in'the operating deck, 21 (FIGURE 3 A split type casing bushing. 59 having handles 60 may be inser'ted inthe casing .spiderxin. a manner well known to the 'artwith use of smaller diameter p'ipes,it being understood'thatzasuitable set ,of slips similar to those. described a with regard to 'slip's 32 would be inserted in the pipe string with that described with regard to FIGURE 1 with slips 32 engaging the large diameter pipe string whilebeing 1 positioned within the casing spider 22., On the operating deck 21, the masterbushing 26 (FIGURE 1), ifrequired,

is removed from the rotary'table 20 and is replaced by casing supporting table bushing (not shown). A set of slips 38 having handles 39 are in pipe-supporting engagement with the table bushings for supporting the smaller pipe 24, the latter being positioned in the vertical opening through the rotary table-20.." This leaves the elevator v19 free to engage the upper end of the pipe-string 24 as desired, or to support a tool or a third string of pipe if desired.

One form of a' slip-and-spider assembly is shown in greater detail in FIGURES 3 and 5. As shown in FIG- URE-5 the casing spid er 22 is made of two parts spread along lines 40 and provided with a hinge pin'41 at one end ailock' pin 42 at the other, end. Thus, to remove the casing spider 22 from around a pipe-sectionpassing therethr'ough, the .lock pin 42 would be pulled out and able manner, asv by mounting it on wheels to move it laterally on the auxiliary deck 23 or providing itwith a hinge 45 adapted to be secured to a cooperating hinge 46 Welded to the deck 23, the hinges being connected by means of a hinge pin 47 extending horizontally. The otherend of 'theplatform-M maybe secured to the deck 23 by any suitable means, as by a removable bolt 48.

Asshown in FIGURES the platform 44 is preferably bifurcated having laterally extending arms 50 and 3 51 arranged in parallel spaced relationship and of the length to stand the, opening 28 through the auxiliary deck 23.

As maybe seen in'FIGURE 3,v the pivot pin 41 extends entirely throughthe casing spider 22 and is fixedly secured at its lowerend tothe platform 44fso that thecasing spider- 22 remains on the top of the platform 44 when thelatter is iraisedto its vertical position as shown in FIGURE 4. The platform 44 or casing spider 22 may rest against. a suitable support 52 on the drilling vessel andthe equipment may be maintained'in place in any 24 and the casing bushing 59 when it was desired to supportthe'pipe string 24..therein. a

This application is a continuation-impart.application of copending application Serial No. 79,842 filed December 30,1960... I

We'claim'as-our invention: g V 1. An offshore structure for carrying out well drilling and completion and ,well work-over operations, said structure adapted to be. positioned .at.a .selected. offshore location in a manner sufiiciently stationary to carry out operations wherein pipe means-may ,:be supported ;at two vertically-displaced levels, said structure comprising an operating deck having a vertical firstoperiing there.-

throughof a isize-suflicient to pass well tools and 7 equipment therethrough. an auxiliary-lower deck 'poistioned. below said operat- "ingdeck and having a verticalsecond .openingtherethrough at least similar in .size to said first opening in said operating deck and in vertical alignment therewith,"

7 .first pipe-engaging means supported by. said. operating deck and arranged concentrically relative to openingin said.deck,.. l second pipe-engaging means carried by said auxiliary deck andadaptedfto be positioned concentrically relativeto said second openingin said auxiliary deck, said. second. pipe-engaging means being movably positioned on said auxiliary deck for-movement into and out of alignment. with said'openingin said deck, and movable platform means interposed between said second pipe-engaging means and .said auxiliary deck for movement into a'ndoutof alignment with said opening in said deck for supporting said second pipesaid first engaging means. 2. Theapparatus. of claim:1 including vertical pivot pin means securing :said second pipe-engaging means to said movable platform means.

means, is bifurcated/with arms extending on either side of the axis offlsaid second opening through said auxiliary decks...

3. Th'e apparatus of claim 1 including horixontal pivot pin means;inengagementwithone side of said platform means and said auxiliary deck to one side of said second opening tlierethro'ughv whereby said platform means is movable from a horizontal position to a substantially vertical position; I

4. The apparatus of claim 3 wherein said platform 5. The apparatus of claim l -including vertical pivot pin vmeans in engagement between said second pipe-engaging means and said platform means at a point intermediate 1,894,093 1/33 Hill 175-171 said horizontal pivot pin means thereof and the axis of 2,068,217 1/ 37 Abegg 24-263.5 said second opening through said auxiliary deck. 2,628,818 2/53 Graham 175-9 6. The apparatus of claim 1 wherein said offshore struc- 193 34 4 1 Bauer et 1 175 5 ture is a floating structure at least when being moved to 2,988,144 6/61 Conrad X an Offshore locatlon- 3,015,360 1/62 Stratton 16666.5 x References Cited by the Examiner 310431255 7/62 Bauer et a1 175 7 X UNITED STATES PATENTS 3,077,227 2/63 Haeber 166-665 X 1,448,172 3/23 Wellensiek 175171 10 CHARLES E, OCONNELL, Primary Examiner,

Claims

1. AN OFFSHORE STRUCTURE FOR CARRYING OUT WELL DRILLING AND COMPLETION AND WELL WORK-OVER OPERATIONS, SAID STRUCTURE ADAPTED TO BE POSITIONED AT A SELECTED OFFSHORE LOCATION IN A MANNER SUFFICIENTLY STATIONARY TO CARRY OUT OPERATIONS WHEREIN PIPE MEANS MAY BE SUPPORTED AT TWO VERTICALLY-DISPLACED LEVELS, SAID STRUCTURE COMPRISING AN OPERATING DECK HAVING A VERTICAL FIRST OPENING THERETHROUGH OF A SIZE SUFFICIENT TO PASS WELL TOOLS AND EQUIPMENT THERETHROUGH. AN AUXILIARY LOWER DECK POSITIONED BELOW SAID OPERATING DECK AND HAVING A VERTICAL SECOND OPENING THERETHROUGH AT LEAST SIMILAR IN SIZE TO SAID FIRST OPENING IN SAID OPERATING DECK AND IN VERTICAL ALIGNMENT THEREWITH, FIRST PIPE-ENGAGING MEANS SUPPORTED BY SAID OPERATING