US 3195639 A
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Description (OCR text may contain errors)
July 20, 1965 R. o. POLLARD ETAL OFF-SHORE DRILLING AND PRODUCTION APPARATUS Filed oct. 1e. 1961 United States Patent O 3,195,639 GFF-SHURE DMLIJING AND PRODUCHN AFPARATUS Robert i). Pollard, Downey, and Charles E. Wakefield, lr.,
Bakersfield, Calif., assignors to Richlield Oil Corporation, Los Angeles, Calif., a corporation oir' Delaware Filed st. 16, 1961, Ser. No. 145,165 8 Claims. (Cl. 16e-66.5)
The present invention relates to off-shore drilling from a oating vessel and more particularly relates to a systern for supporting a casing riser and such drilling equipment as a blowout preventeror other drilling equipment from the drilling barge whereby the blowout preventer can be released from the casing riser and raised to the barge for repairs without losing drilling iiuid.
Heretofore it has been necessary to mount the blowout prevention equipment either at the ocean'oor or to a rigid structure on the drilling barge. In the prior art, where a casing riser was utilized in off-shore drilling and the blowout prevention equipment axed thereto, it was not feasible to suspend the blowout prevention equipment under the drilling barge through the access well since the blowout preventer could not be raised to the barge for service, without also raising the casing riser. In deep water drilling where the ocean floor is not accessibleto divers, the positioning of the primary blowout preventer on the ocean floor is not feasible since the casing riser must be brought to the barge stand by stand in order to raise the blowout preventer for repairs of replacements. When the blowout prevention equipment is iiXed on the barge, all Ipitching motion must be taken above the blowout prevention equipment but below the working iioor, thus requiring a substructure supporting the working iloor to be at least the height of the slip-joint used. In other words, the free board or portion of the vessel above the water level must necessarily be increased when the blowout prevention equipment is fixed on .the drilling barge.
It is therefore a primary object of our present invention to provide an oli-shore drilling system wherein the casing riser and the blowout preventer are releasably fastened together and supported from the barge in such a manner that the blowout preventer can be disconnected from the casing riser and raised to the barge for repairs without breaking the drilling tluid return path through the riser annulus.
It is also an object of our present invention to provide a releasable safety joint extension whereby the rigid connection between the riser and the blowout preventer can be disconnected while maintaining iiuid communication between the riser and the blowout preventer.
It is also an object of our present invention to provide an olf-shore drilling system wherein a minimum free board and sub-structure height are required.
It is a further object of our present invention to provide an oil-shore drilling apparatus whereby a casing riser and a blowout preventer are supported by constant tension cable lines at high ocean wave action.
Other objects and a more complete understanding of our present invention may be had by reference to the following specification and the appended claims taken in conjunction with the following drawings, in which:
FIGURE 1 shows in elevation partially in section, olishore drilling apparatus with drilling tools extending through a drilling barge access opening.
FIGURE 2 shows in cross-sectional elevation an enlarged view of the releasable safety joint extension.
FIGURE 3 shows the safety joint extension of FIG- URE 1 in cross-section, with the blowout preventer raised to the barge.
Briey described, our present invention relates to an off-shore drilling system whereby a blowout preventer 30 and a casing riser 26 may together be supported from a drilling barge 10 and the blowout preventer disconnected from the casing riser and raised to the drilling barge for repair or replacement of parts without breaking the return drilling fluid path through the riser, by providing an extended safety latch joint connection 44 between the riser and the blowout preventer.
Referring now more particularly to the drawings, in FIGURE l, a iioating barge 10 having an access well 12 therein and a working floor 13 is utilized for drilling a well bore 14 in a submarine formation. A drilling base 18 with a conductor pipe 20 extending therethrough may be aiixed to the formation at the well site and drilling performed by rotating a drill pipe 22 having a drill bit 23 thereon through the base and conductor pipe. The drill pipe is rotated with conventional rotary drive apparatus preferably located on the barge. A surface casing 24 is landed in the formation after the Well has been suiiiciently deepened. Drilling fluid may be returned to the barge mud tanks through the surface casing-drill pipe annulus, thence through the casing riser 26 annulus and pitcher nipple 28 to the mud-treating tanks (not shown). Blowouts are controlled in the well by a blowout preventer 30 which is preferably suspended within the access well 12 as shown in FIGURE 1.
Additional blowout prevention equipment 32 may be provided at the well-head to serve as auxiliary blowout prevention equipment and to perform the blowout prevention function when the blowout preventer 30 is out of service for repairs, etc. The addition blowout preventers 32 are not, strictly speaking, essential to the operation of our present invention, although it is preferable practice to use them. A riser landing mandrel (not shown) protrudes from the conductor pipe 20 and is latched by the latching gate 34. Funnel 36 is provided to aid in guiding the lower end of the casing riser and the blowout prevention equipment 32 onto the riser landing mandrel. A retrievable television mount 38 enables the operator at the barge to view the auxiliary blowout prevention and latching equipment as it engages the riser latching mandrel above the landing base 18.
The casing riser assemblage 26 and the blowout preventer 3Q are supported from the drilling barge with cables 4t) which are maintained in constant tension by any well-known means, e.g. oats, buoys, counter weights, etc., although we prefer to use for this purpose compensating hydraulic cylinders 42. Thus, as the drilling barge is raised or lowered with the tide and wave action, more or less, cable 40 is supplied under the same tension by the self-compensating hydraulic cylinders 42. Preferably the riser pipe and the blowout preventer are supported from the barge by a cantilever arrangement through the use of sheaves 43.
A manual release safety joint 44, for example the releasing safety joint shown and described on page 4987 of the 1960-61 Composite Catalog of Oil Field Equipment and Services, published by the Gulf Publishing Company, is provided in the casing riser operatively above the cable support eyes d6 which connects the cables 40 to the release joint and casing riser.
The internal member 4S of the safety latch is provided with a telescopic extension sleeve 50 so that the joint 44 may be disconnected and the lblowout preventer including the internal portion 4S of the latch joint raised vertically to the access well 12, for repairs, as shown in phantom line in FIGURE l, without breaking the drilling fluid return pass through the casing riser or in the event that the drill pipe has been removed, losing contact with the riser below the joint. The length of the sleeve 50 is Y preferably approximately the depth to which the blowout preventer 30 is submerged through the access well 12 into the ocean so that when the blowout preventer and the internal portion or mandrel 48 of the safety joint 44 are lifted to the barge, the extension sleeve Si) will still be within the casing riser telescopic extension 52, as shown in FIGURE 3. A stop 54 is provided at the lowerend of the extension sleeve 50 so that the blowout preventer will not be raised so high that the extension sleeve 5i) will pull out of the riser extension 52. Y
The riser pipe 26 has an enlarged riser extension 52 connected therewith with an appropriate cross-over meinber 56 and a coupling member 58 so that the internal diameter of the casing riser is approximately the same when the extensiony sleeve 5t) is telescope/d with the cas ing riser extension 52. The casing riser extension 52 is connected to the outer barrel 53 of the safety release joint 44 with a suitable coupling such as the threaded coupling 6i), as shown in FlGURE 2. Y The telescopic part 50 may be raised only when the safety joint 44 is mechanically released or disconnected. In effect, the telescopic parts 50 and 52 constitute a high pressure telescopic joint.. y e Y y Any conventional hoisting means may be utilized to raise and lower vthe blowout preventer 3i) into the access opening, such as the pick-up lines'61 which are connected to eye supportsl on blowout preventer 30, or the top of the riser may be latched with elevators and pulled up with the draw works or crane.
Above the blowout preventer 30 the working slip-joint 62 is provided which comprises a pair of telescopic .pipes 64 and the purpose of whichis to compensate for rise and fall of the bargeand maintain a fixed relationship between the pitcher nipple 28 and machinery on deck.
v The riser extension assemblage 67 is centralized within the access opening 12 by a pair of Ystabilizer lines 68 which are fastened to the pipe 66 and pass over a pair of vsheaves 70. v
Thus our present linvention provides an apparatus whereby a blowout preventer which is suspended with a casing riser connected thereto may be raised to the drilling barge for repair without lifting the entire casing riser which, of course, would -require unlatching the casing riser Vat the well-head. This is accomplished in our presentv invention by providing an extension sleeve on the internal portion of a conventional safety releasejoint 44 so that the drilling fluid return path is not broken when the blowout preventer is released inthe casing riser nor is contact lost 2. VApparatus for removing a blowout preventer from drilling apparatus extending from a vessel on the surface of a body of water to a well in a formation underlying said body of water comprising:V a landing base adapted to be aflixed to said formation, tubular apparatus extendable between said landing base and said drilling vessel delining a fluid path between said well and said vessel, said tubular apparatus having a sleeve near the upper portion thereof, a blowout preventer having a telescopic part extending therefrom and adapted to be received by said sleeve, said telescopic part being so arranged and constructed to enable raising of said blowout preventer to the surface of said body of water while maintaining fluid communication through said tubular apparatus with said well, meansfor supporting said tubular apparatus from said vessel independently of said blowout preventer, releasable fastening means operatively associated with theupper portion of said sleeve'and said telescopic part'for fastening of said telescopic part and said sleeve, and means for raising said blowout preventer upon release of said fastening means. 3. The'apparatus of claim 2 wherein said telescopic part extending from said blowout preventer has a stop member attached to the lower portion thereof. 4. The apparatus of claim 2 including means for maintaining said Vsupporting means in constant tension.
, 5. The apparatus of claim 2 including compensating hydraulic cylinders affixed to said vessel and wherein said supporting means .are maintained inV constant tension by said hydraulic cylinders;
, 6. Apparatus for removing a blowout preventer from drilling'apparatus extending from a vessel on the surface of a body of water to a well inea formation underlying said bodyvof4 Water without losing fluid contact between said vessel .and said well comprising: a landing base afwith the casing riser when the blowout preventer is deorder to set forth the best mode of operation presentlyV known, the scope of our present invention should not be limited to the details set forth, but should be given the full breadth of the appended claims.
1. Apparatus for removing an upper portion of a drilling apparatus extending from a vessel on the surface of abody of Water into a well in a formation underlying said body of water, comprising: a landing base afxed to said formation, drilling apparatus comprising an upper removable part and a lower part, said lower part having a sleeve atthe upper end thereof, and said upper part having a telescopic part extending therefrom, said telescopic part being adapted for receipt in telescopic relationship in said sleeve and of sufficient length to permit the raising of said blowout preventer to the surface of said body of water without losing uid contact through said drilling apparatus with said well, means for independently supporting said upper and lower parts of said drilling apparatus from said vessel, releasable'fastening means operatively associated with the upper end of said sleeve and said telexed to said formation, drilling apparatus extending downwardly through said body of waterlying between said base and said drilling vessel, said drilling apparatus defining a Huid return path from said landing base to said vessel and comprising a'blowout preventer and a casing riser, said riser having a sleeve near the upper end thereof and-said blowout Vpreventer Vhaving a telescopic part extending therefrom and adaptedfor receipt in said sleeve in telescopic relationship, said telescopic part being ofrsuicient length that fluid contact with said sleeve can be maintained when -saidblowout preventer is raised to said vessel, means for supporting said riser from said vessel independently of said blowout preventer, and releasable fastening means connected to the upper end of said sleeve and said Vtelescopic part for releasing said riser from said blowout-preventer whereby said blowout preventer may be .raised to said vessel without breaking said iiuid return path 1 j 7. The apparatus of claim 6 wherein said releasable fastening means comprise a safety release joint having a mandrel and a barrel, said barrel being connected to said riser, and said mandrel being connected to said blowoutV preventer. 1
8. The apparatus of claim 7 wherein said mandrel of blowout preventer.
said safety joint is connected to said telescopic part of said` CHARLES E. ocoNNELL, Primary Examiner. NORMAN YUDKOFF, Examiner. i