US2476309A - Apparatus for subaqueous geologic prospecting - Google Patents

Description

`Iuly 19, 1949.

Filed May 25, 1944 2 Sheets-Sheet l Zie/ la@ July 19, 1949. W. B. LANG APPARATUS FOR SUBAQUEOUS GEOLOGIC PROSPECTING Filed May 25., 1944 2 Sheets-Sheet 2 Patented July 19, 1949 APPARATUS FOR SUBAQUSEOUS yGEOL'OGIC PRosPEctuNG Walter B. Lang, Roswell, NrMex.

Application May ,25, 1944, Serial No.. 537,285

9 Claims.

(Granted under the act of March 3, 1883, as amended April 30, 1928;.,370.Q. G. 757) The invention described. herein may be manufactured and used hy or for the Goverment of the United vStates for lgovern-mental purposes Without the payment to me of any royalty thereon in. accordance with thev provisions of the act 'of .april 3G, 1.928- (Ch. 4.60, 45 Stat. L. 467).

My invention relates to apparatus for subaque- .ous geologic prospecting by means of a drill or a Lcore and particularly to prospecting for and the subsequent production of oil and gas beneath ybodies .of Water such as `inthe coastal 4:continental shelves, inland lakes-fandurivers.

My .invent-ion .provides .means for prospecting from a platform anchored in :deep water -and therefore beyond the shallow waters in which the bed of the ocean can conveniently be used to support core-drilling apparatus. Myprospecting apparatus may be used where the ocean is three .hundred to three thousand feet or more deep. My invention .provides 1a means .for prospecting in the Abeds of rivers and. inland lakes, Yas Well as practically al1 of the areas 4of the -subaqueous continental shelves, more: particularly those .areas where deep oil seeps are known to` exist, such as olf the California coast. Y

In the accompanying draw-ings.:

Figure 1 is lan. elevation of my apparatus, rdiagrammatically `indicating the essential elements inoperative position.

Figure 2 is -a plan view.

Fig-ure 3 -isan enlarged detail elevatiom. partly.

in section.

,Figure 4 is -an enlargedvertical .section showing .my .driving gears.

Figure 5 is a. cross-section on. the line 55 of: :i

platform is supported by a plurality of floats 6.,

A casing buoy 'I is fastened to a well casing 8 below the elevation of low tide,.'so that they buoy wiilalways be submerged and constantly exert 'lifting .force on the well casing.

.A plurality of anchors 9 provided. with suitable anchor cables i0- serve .to .maintain my platform over a selected site..and..for each. anchor there is warning buoy IVI attached to the anchor by a cable For the .purpose of enabling uncoupling of -theiioatingstructure lfrom the well .casing -8 when it is desired toimove the floating structure to anew vlocation. -or a safe location in case Aof threatenedstor-m, the uppermost :casing section 2l' is detachably connected to the casing just above the high Water mark. as shown in Fig. 3 land hereinafter described, and the floating structure, Aas indicated in Figs. 1 .and 2, is arranged to provide aaclear tunnel I3 extending from one `face of the structure to a position underlying the drill -tower 2. This 'clear tunnel I3 is provided 'by'appropriete location of the ioats `I5 and 'strut-work of the structure to enable the structure to be Withdrawn 'from superposition above the .projecting endof casing 8 and the supporting iioat .'I. ISuitable cable windlasses HI provide means for maintaining my device -in posi-tion` against wave .and current action, as Well as :against the torque due to my core bor-ing drill.

An embedded length of Well casing 8 :is indicated b-y 45, the length `of the embedded portion :depending largely upon the ycharacter Iof the ocean bed. drilled hole is indicated at I6 .anda plurality of torque-lines or cables |=1 each secured to an anchor .9 may yIne-paid yout or shortened by' gym-controlled windlass operating means not shown.

Thebottom of the casing `8 is provided with n. :suitablefan-nular bit Ill-which isrotated to-cut into the rock iby a standard drilling machine :(not shown) which is temporarily mounted .tor that purposeon the platform to permit embedding the par-t I5. By any suitable and well-known process, a cement grout is introduced through the casing and forced outwardly -toform-.a :permanent seal at i9 :between the lportion |-5 of the well casing and thefsurroundin-g -rockrcf the -ocean `floor. A- bolted pipe -clam-p 2i!y provides a supporting stopY for lmy :float 1 which has` an axial tunnell through which succes-sive sections of casingare passed, while Ya similar-clamp 2 Iy transmits flif-ting lforceirom my float 1 'to 4my -casi-ng 8`a-fter the .latter sealed in *the rock. .My ioat 1 Yis provided -near the bottom With-adifferential-check valve 22 through which Water-maybe expelled by admitting acompressed air through-a xvalve .7.31 ande. 4pipe 2A from .an air compresser operated by :asuitable Ymotor 2.5, both ofwhich @are mounted `on the working platform I.-

Afsection .21ct rthe casing 8 :forms aguide .for an internally-rnachir-iedf.sleevel A2.8 .having .a concen- -tric gimbal 29. Depending. from the platform I, ras .shown in Fig. .3,.there are bracket elements which provide 1bea-rings Afor .the trunnions :of .the Cardan joint-.29., which .tr-unnions, as shown 5, extendvat rightangles -to the Ytrunnions .pivotally connecting the Cardan ring 29 to the sleeve 28. By this arrangement provision is made for a sliding and gyral connection between the casing 8-21 and the platform I, thus providing a preferred form of means to accommodate movement of the platform relative to the casing due to ground swell or other wave action, wind, and tide drift. A hollow drill stem 3| has an upper section or griefstem 32 of non-circular section which terminates in a swivel 33 provided with gooseneck 34 through which flushing water is supplied to the hollow drill stem 3|. The casing section 21 is provided with a suitable overow opening or port B for the discharge of flushing water carrying the cuttings from the drill |8. The swivel is provided with an eye 35 to which a drill-hoisting cable 36 is attached. The cable 36 is passed over a pulley of a crown block 31 mounted on the drill tower 2. The cable is passed downwardly over a pulley 38 on the free end of a lever 39 which is pivotally attached at 40 to the casing 8. The lever 39 is also pivotally attached intermediate of its ends to a strut 4| attached to the working platform The strut 4| in the form shown is attached to one of the brackets 3|! which provides a bearing for the Cardan joint 29. The cable 36 is passed from the pulley 38 around a windlass 42 operated by a suitable motor indicated at 43.

A core drill is rotated by the grief-stem 32, freely slidable in the chuck 3 la driven by a turntable 44 which vis thus free to rise and fall relative to the grief-stem 32. The turntable 44 is driven by a bevel gear 45 mounted in a collar 46 on the upper casing 21'. The turntable 44 is operatively connected by a splined universal driving shaft 41 having a torque rod 48, which keeps the gear 45, Fig. 4, aligned with the shaft 41, to a suitable motor 49 mounted on the working platform Preferably, my floats 6 are submerged to a depth at which wave action is very slight-for example, at 100 feet below the normal water line of my iioat which is preferably designed to offer a minimum of resistance to current and wave action, so that the rise and fall of my working platform and my drill tower 2 is less than that of surface oating craft, while the fluctuations due to the tide may also be reduced by varying the volume of water in my ballast tanks 6. The well casing 8 and 21, iioat 1, and turntable 44 do not rise or fall with the waves or tide, while my working platform with everything supported thereby, including my drill tower 2, are subject to iiuctuations with respect to the ocean bottom and the casing attached thereto. For this reason it is necessary to provide a exible turntable drive and means for automatically taking up slack in my cable 36, which are provided for by the splined universal driving shaft 41 and by the arcuate movement of the pulley 38 which moves downwardly as my drill tower 2 moves down and vice versa. As the entire floating structure including strut 4| moves relative to the swivel 33 by the same amount that it moves relative to pivot point 40 it is clear that one unit of such motion in a downward direction produces one unit of slack in cable 36 which must be compensated for by movement of the pulley 38 downwardly by onehalf unit of motion relative to the iioating structure and hence to the pivot 4|a carried thereby. Accordingly, it is apparent that the lever arm 40-38 is related to the lever arm 4ll-4Ia as 3 is to 2 so that as point 4 la moves downwardly one unit, the pulley 38 will move downwardly half as much again, the same relation holding good during upward movement of the floating parts.

My invention makes possible subaqueous geologic prospecting under depths of water which heretofore have been too great with available apparatus. Should my drill tap a supply of oil or gas,

5 storage and oil refining equipment may be mounted on my working platform. Then either crude or refined oil may be delivered directly to ships which may stop for supplies.

Whenever it is desired to move my apparatus, it is only necessary to remove the drill rods to close the air valve 23 to my iioat 1, disconnect the air pipe between this valve and my compresser 25; then uncouple the upper section 21 of my well casing from the lower section 8 and cap the latter; then move my apparatus until the pipe 8 has emerged from the opening |3. After an oil and/or gas supply has been tapped, should it be desired to convey it ashore, suitable piping, such as is already known in this art, may be coupled to my well casing 8. Whenever it is decided to abandon a well which fails to produce oil in suicient quantity to warrant development, the hole may be sealed as by plugging and cementing, and a blasting charge be then use to cut the casing loose from the ocean bed. Submarine television apparatus may be utilized to inspect/the progressive stages of the work.

The size and shape of my oating structure may be varied in accordance with local conditions and the type of prospecting to be undertaken. Means are indicated for maintaining my structure in place without injury to a string of pipe and the attached float serves to relieve the lower portion of a string of pipe from excessive strains. This also makes it possible to remove all weight of the pipe from the platform and makes it independent of my floating equipment.

My mounting of the driving turntable on the string of pipe with yielding connections between the pipe and my floating structure provides for necessary freedom of relative movement, and serves to eliminate iluctuations of pressure on the core cutting bit, or raising it olf the bottom during drilling with the risk of destroying the core. For 45 unusually long strings of pipe a trussed brace may be added to give it rigidity.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modifications, among 50 others being the making of my buoy 1 in axiallydivided sections each provided with a venting check valve 22 and a supply pipe 24, as well as any suitable means for coupling these sections about the well casing 8 after the latter is cemented in place. Changes, therefore, in the construction and arrangement may be made without departing from the spirit and scope of the invention as disclosed in the appended claims, in which it is my intention to claim all novelty inherent in my invention' as broadly as possible in view of the prior art.

What I claim is:

1. In a system of submarine drilling employing a drilling rig carried by a iioating platform, a drill casing and a drill stem operable through the casing; the method which consists in (a) locating the floating platform in a position overlying the site at which it is desired to conduct the drilling; (b) anchoring the floating platform at said location to limit its lateral movement under tide,

wind, wave and ground swell effects; (c) making up, in suspension, a string of casing adapted to reach the site from the floating platform and terminating in a drilling shoe at its lower end;

(d) drilling in said string of casing and cementing the drilled in casing in place so as to secure a firm hold on the subterranean site; (e) supporting said casing to maintain it substantially erect above the site of operations; (f) connecting the so supported casing to said floating platform in a manner providing for vertical and gyral movement of the platform relative to the site; (y) lowering a drilling means through the casing into drilling relation with the site, and connecting said drilling means to the cable of the rig; and (h) drilling with said drilling means While compensating positively and continuously for tendency of the rig cable to become too slack or too short due to rising and falling motion of the platform relative to the site.

2. A method according to claim l, in which said last-named compensating step includes the step of continuously and positively slacking off and picking up the cable as said platform rises and falls relative to the site.

3. A method according to claim 1,in which said last-named compensating step includes the step of slacking olf and picking up the cable as said platform rises and falls relative to the site, and in which compensation for tidal and other relatively slow changes of elevation of the Water surface relative to the site is effected by varying the buoyancy of said floating platform.

4. Flexible drilling apparatus for drilling at deep water submarine sites, comprising a floating platform adapted to be located in a position overlying the site at which it is desired to conduct the drilling, means for anchoring said platform so that its lateral movement under wind, wave and tide elfects is limited to a relatively small percentage of the depth of water at the site; a drill casing having its lower end secured at the site and its upper end connected to the floating platform in a manner providing for vertical and gyral movement of the platform relative to the site; drilling means within the casing; a cable secured to said drilling means; a cable drum on said platform to which said cable is attached; and means for compensating continuously and positively for tendency of the cable to become too slack or too short due to rising and falling motion of the platform relative to the site.

5. Flexible deep water drilling apparatus according to claim 4, in which the upper end of the casing is slidable through a sleeve which in turn is mounted for gyral movement relative to said floating platform.

6. Flexible deep Water drilling apparatus according to claim 4, in which the upper end of the casing is slidable through a sleeve which is mounted in a Cardan joint attached to said floating platform.

7. Flexible deep water drilling apparatus according to claim 4, in which said compensating means comprises a linkage movable by movement of said platform relative to said casing, said linkage having a movable arm carrying an idler pulley engaging a bight in said cable and arranged to positively and continuously increase and decrease the length of said bight to compensate for falling and rising motion of said platform rela tive to said casing.

8. In a flexible deep water drilling apparatus a drill casing secured at its bottom end at the subterranean site at which it is desired to conduct the drilling, means for maintaining said casing substantially erect above the site, said casing at its upper end terminating above the high Water mark; a floating platform adapted to be located in a position overlying the upper end of said casing, strut-Work and buoyancy chambers supporting said platform; a drilling tower carried by said platform; a section of drill casing secured to said platform in underlying relation to said tower and adapted to be detachably secured to the upper end of the first-named casing; flexible means for anchoring said floating casing in position; said strut-work and buoyancy chambers being positioned to provide a tunnel from the edge of said platform to said casing section, whereby said floating structure may be disconnected from said first-named casing and moved to and from the site of operations without disturbance of said first-named casing.

9. In a drilling apparatus for drilling at deep submarine sites, a drill casing having an annular bit at its bottom end drilled into the submarine site and sealed thereto, said casing being of such length as to be incapable of sustaining itself erect under the conditions existing at the site, and a f buoyancy chamber secured to the upper part of said drill casing, said buoyancy chamber constantly exerting lifting force at the upper part of said casing and applying pulling tension to the underlying part of the casing preventing buckling of said casing and maintaining it substantially erect above the site.

WALTER B. LANG.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date Y 496,729 Fairchild May 2, 1893 1,517,556 Grant Dec. 2, 1924 2,033,035 Koons Mar. 3, 1936 2,171,672 Plummer Sept. 5, 1939 2,187,871V Voorhees Jan. 23, 1940 2,239,531 Laurie Apr. 22, 1941 2,244,830 Doe et al June 10, 1941 2,248,051 Armstrong July 8, 1941 FOREIGN PATENTS Number Country Date 160,865 Great Britain Apr. 7, 1921

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