US 3353364 A
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Description (OCR text may contain errors)
Nov. 21, 1967 J. E. BLANDING ETAL 3,353,354
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER 17 Sheets-Sheet 1 Filed April 26, 1962 their ATTORNEYS Nov. 21, 1967 J. E. BLANDING ETAL Filed April 26, 1962 UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER 17 Sheets- Sheet 2 "II II! JAMES VINCE TINVENTORS' N HARRING N EDMUND c. TRAGESER 8T0 JOHN E. BLANDING- their ATTORNEYS J. E. BLANDING 'ETAL 3,
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UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26,- 1962 17 Sheets-Sheet 4 IN VEN TORS.
JAMES VINCENT HARRINGTON, EDMUND C. TRAGESER 8 JOHN E. BLANDING their ATTORNEYS.
1967 I J. E. BLANDING ETAL UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER l7 Sheets-Sheet 5 Filed April 26, 1962 w 5T8 MW e Mmmm Q SD & V EN N A TML m5 M E M1 VD S W C. .M
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INVENTORS. JAMES'VINCENT HARRINGTON, EDMUND c. TR'AGESER 8.
JOHN E. BLANDING h ATTORNEYS.
J. E. BLANDING ETAL 3,353,364
17 Sheets-Sheet 7 0 0 0 in: P wn a W INVENTORS JOHN. E. BLANDI NG,
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Nov. 21, 1967 Filed April 26, 1962 EDMUND C. TRAGESER a V JAMES VINCENT HARRINGTON their 7 ATTORNEYS Nov. 21, 1967 J.E. BLANDING ETAL 3,353,364
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed A ril 26, 1962 1-7 Shqets-Sheet s EDMUND C. TRAGESER 8: JAMES VINCENT HARRINGTON M 4 M, @MJ
' iheir ATTORNEYS 1967 J. E. BLANDING ETAL 3,353,364
UNDERWATER WELL ENC LOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 17 Sheets-Sheet 9 FIG. /2
I NVENTORS JOHN E; BLANDING,
EDMUND QTRAGESER & JAMES VINCENT HARRINGTON the r ATTORNEYS 1967 J, E. BLANDING ETAL 3,353,364
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 17 Sheets-Sheet 1O FIG. /4
INVENTORS JOHN E. BLANDING, EDMUND C. TRAGESER 8 JAMES VINCENT HARRINGTON iheir ATTORNEYS Nov. 21, 1967 3,353,364
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER J. E. BLANDING ETAL l7 Sheets-Sheet 11 Filed April 26, 1962 INVENTORS JOHN E. BLANDING,
EDMUND C. TRAGESER 8| v JAMES VINCENT HARRINGTON their ATTORNEYS I 2131967 7 J.E. BLAN'DING-ETALI. 3,353,364
UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed A ril 26, 1962 17 Sheets-Sheet 12 Hat/7 INVENTO S JOHN E. BLANDING, EDMUND C. TRAGESER 8 JAMES VINCENT HARRINGTON 5 q P @MMZ their ATTORNEYS 21, 5 J. E. BLANDING ETAL 3,353,364
' UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 17 Sheets-Sheet 15 MIN F/a/a INVENTORS JOHN E. BLANDING, EDMUND C. TRAGESER Bu JAMES VINCENT HARRINGTON I Jhe ir ATTORNEYS O 1957 J. E. BLANDING ETAL UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 INVENTORS JOHN E. BLANDING,
EDMUND C.TRAGESER a JAMES VINCENT HARRINGTON ,6 W their ATTORNEYS" 17 Sheets-Sheet 14 Nov. 21, v1967 J. E. BLANDING ETAL 3,353,364
UND ERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER l7 Sheets-Shet 15 Filed April '26, 1962 INVENTORS JOHN E. BLANDING,
EDMUND C-TRAGESER 7 BY JAMES VINCENT HARRINGTON I W, PW
ave-= their ATTORNEYS NOV. 21, 1967 BLANDmG L- 3,353,364
UNDERWATER WELL'ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 17 Sheets-Sheet 16 INVENTORS JOHN E. BLANDING heir ATTORNEYS 1967 J. E. BLANDING ETAL UNDERWATER WELL ENCLOSING CAPSULE AND SERVICE CHAMBER Filed April 26, 1962 17 Sheets$heet 17 m F/G. 22-
INVENTORS JOHN E. BLANDING, EDMUND C.TRAGESER a JAMES VINCENT HARRINGTON their ATTORNEYS United States Patent Ofiice 3,353,364 Patented Nov. 21, 1967 3,353,364 UNDERWATER WELL EN CLOSING CAPSULE AND SERVICE CHAMBER John E. Blanding, Old Lyme, Edmund C. Trageser, Norwieh, and James Vincent Harrington, Mystic, Conn., assignors to General Dynamics Corporation, New York, N.Y., a corporation of Delaware Filed Apr. 26, 1962, Ser. No. 193,040 16 Claims. (CI. 6169) The present invention relates to underwater drilling methods and apparatus and, more particularly, to novel methods and apparatus permitting a separation of the drilling, producing, and servicing phases of underwater well construction and operation.
This is a continuation-in-part of our application Ser. No. 81,543, filed Jan. 9, 1961, and now abandoned The rapid depletion of the natural resources underlying the earths land masses and the growing demand for raw materials have led to an urgent quest to develop means for exploiting deposits beneath the floor of the sea and in other areas underlying water. A number of devices have been developed for this purpose, including notably the mobile platforms now in operation off the coasts of the United States mainland. However, conventional mobile platforms and similar apparatus have not provided a complete solution to the problem.
It is an object of the present invention, accordingly, to provide new and improved means for drilling, operating and servicing wells under the water.
A further object of the invention is to provide new and improved means for enclosing an underwater wellhead, keeping it dry, and enabling workmen to gain access to it for well maintenance.
Still another object of the invention is to provide means for lowering workmen to the wellhead for inspection and maintenance purposes.
Another object of the invention is to provide separate pieces of equipment to accomplish the drilling, operating, and servicing of underwater wells, including means for drilling a well, a watertight capsule for enclosing the wellhead, and personnel-carrying means for servicing the equipment at the wellhead at periodic intervals.
Another object of the invention is to make possible the replacement of conventional platforms by a small underwater capsule which is inexpensive and undisturbed by weather and shipping.
These and other objects are attained, in a first representative embodiment of the invention, by providing a submersible vessel which is outfitted with the accouterments of the well driller. Attached to the vessels exterior surface is a watertight capsule adapted sealably to pass drilling and easing means. Drilling means are extended from the vessel through the capsule for drilling a well, and casing is inserted into the well and sealed to the capsule. When the well is completed, the capsule and the vessel are sealed off from each other and separated. The capsule remains on the floor of the sea enclosing the wellhead and keeping the equipment at the wellhead dry, and the vessel is available for drilling another well. At periodic intervals a service chamber may be lowered to facilitate inspection and repair of the equipment at the wellhead. A line extending from the capsule to a float on the surface or a coded transponder on the capsule facilitates relocation of the capsule.
A second embodiment of the invention has numerous features which adapt it particularly for shallow-water drilling. For example, means are provided for mounting blowout preventers above the waters surface.
A third embodiment of the invention, adapted particularly for drilling in great water depths,has many novel features including novel hold-down equipment for holding down underwater-well apparatus. The apparatus so held includes a plurality of submersible chambers mounted upon a wellhead in vertically-stacked relation on a floor underlying water.
For an understanding of further particulars of the invention, reference may be made to the following detailed description of three representative embodiments thereof and to the accompanying figures of the drawings, in which FIGS. 1-6 illustrate the first embodiment, FIGS. 7-13 the second, and FIGS. 14-22 the third. More particularly:
FIG. 1 is a perspective view, partially broken away, of a submersible vessel supported by a foundation pad on a floor underlying water and sealably attached to a watertight capsule in accordance with a first representative embodiment of the invention;
FIG. 2 is a detailed view in elevation (partly sectioned along the line 22 of FIG. 4) of the capsule as it appears when it is attached to the submersible vessel and has typical drilling equipment in place;
FIG. 3 is a detailed view in elevation (partly sectioned along the line 3-3 of FIG. 4) of the capsule as it appears after completion of the well, substitution of well-completion equipment for the drilling equipment, placement of a watertight hatch on the capsule, and departure of the submersible vessel;
FIG. 4 is a plan view, partially broken away, showing the construction of the capsule-hatch seal;
FIG. 5 is a diagrammatic representation of a service chamber being lowered from a tender to the capsule at the wellhead for the purpose of facilitating inspection or repairs in accordance with the invention;
FIG. 6 is a view in elevation, partially broken away, of the service chamber in position on top of the capsule and forming a watertight seal therewith;
FIG. 7 is a perspective view of apparatus for lowering a capsule support easing into a conductor pipe driven or otherwise placed into a shallow-sea floor in accordance with the invention;
FIG. 8 is a partly-sectioned elevational view of a drilling capsule particularly suited for drilling in relatively shallow water;
FIG. 9 is a partly-sectioned fragmentary elevational view of the mechanism by which the watertightintegr'ity of the capsule shown in FIG. 8 is established along an annular junction of upper and lower halves of the capsule and by which the upper half is guided into sealing relation with the lower half; 1
FIG. 10 is a partly-sectioned detailed elevational view of one form of adaptor constructed in accordance with the invention;
FIG. 11 is a vertical sectional view of a wellhead and associated means constructed in accordance with the invention for hanging a plurality of casings down into a well during a drilling operation and for supporting a plurality of upper casing extensions associated therewith;
FIG. 12 is a partly-sectioned elevational view of a production capsule particularly adapted for use in relatively shallow waters;
FIG. 13 is a partly-sectioned fragmentary elevational view of a hydraulic lifting device shown also in FIG. 12;
FIG. 14 is a diagrammatic view of an overall arrangement of capsule, adaptor, separating equipment, production buoy, underwater storage tank, surface vessel and other apparatus particularly adapted for use in'connection with wells drilled in great depths of water;
FIG. 15 is a partly-sectioned elevational view of a conductor pipe and a foundation pad which are being prepared at great depth to receive a drilling capsule;
FIG. 16 is a partly-broken-away and partly-sectioned I elevational view of a capsule enclosing a wellhead on the floor of the sea, the structure being particularly adapted for use in drilling in great depths of water;
FIG. 17 is a partly-sectioned elevational view of a deep-water capsule having well-completion valves in place and hydraulically-operated hold-downs from a superior chamber inserted in hold-down tubes attached to the capsule;
FIG. 18 is a partly-sectioned elevational view of a novel adaptor for use with the capsule shown in FIG.
cordance with the invention;
FIG. 21 is a partly-sectioned elevational view of a center-line elevator or submersible personnel chamber constructed in accordance with the invention; and
- FIG. 22 is a partly-sectioned elevational view of a production buoy constructed in accordance with the invention.
While for purposes of exposition the three embodiments are treated separately, various apparatus and methods described in connection with one embodiment may also be used in combination with apparatus and methods which are described as relating to another embodiment.
First embodiment: Drilling a well from a submersible vessel In FIG. 1 a submersible vessel '10 is shown permanently secured to a foundation pad 11 at the bottom of the sea by remotely-controlled vertical adjustors 13. As many adjustors are used as may be necessary, and, in any event, other adjustors similar to the ones shown are locatedon the side of the vessel opposite the side visible in the figure, so that the vessel 10 is provided with at least four legs formed in a manner hereinafter set forth to hold down the vessel 10 and make final adjustments in its position when it arrives at the bottom.
The adjustors 13 are permanently attached to the vessel 10 and comprise cylinders 13a fitting sealably about rams 13b slidably mounted therein. Ram extensions 130 which extend downwardly from the rams 13b and sealably through the bottoms of the cylinders 13a to form .the legsjare secured to the pad 11 by ball-in-socket connections 13e or other (preferably universal) connections. Fluid lines 13d communicate with opposite ends of the cylinders 13a and extend to conventional apparatus (not shown) mounted within the vessel 10 for supplying a fluid to and exhausting it from the cylinders 13a, so that the' ram extensions 130 may be remotely moved upwardly or downwardly to provide proper control of the position of the vessel 10.
A capsule 14 extending through a hole 15 in-the pad 11 forms a watertight seal at its upper end with the vessel 10 by means of a mechanism indicated generally at 16, hereinafter described in detail, and at its lower end with .a well casing 17.
Inasmuch as the pad '11 may settle during the drilling operation, it may be necessary to adjust the position of the vessel 10 with respect to the pad 11 by means of the adjustors 13 in order to preserve the seals at the end of the capsule 14. Relative vertical movement of the vessel 10 with respect to the pad 11 is readily elfected by equal parallel movements of the ad justors 13. Limited horizontal movement of the vessel 10 with respect to the pad 11 is efiected by certain unequal movements of the adjustors 13.
' Lugs 18 help to establish the proper orientation of the capsule 14 with respect to the vessel 10 and thereby facilitate the forming of the seal by means of the mechanism 16. The lugs 18 are conveniently three in number and spaced at -degree intervals around the periphery of the capsule 14.
A traveling block 20 is used to lower a kelly 21, a drillpipe (not shown in FIG. 1), and the casing 17 into the capsule 14 and sealably through sealing means such as locks (not shown) in the bottom thereof.
FIG. 2 shows in detail the structure of the capsule 14 and the equipment associated therewith during the drilling process. The top 22 of the wellhead 23, which is securely mounted in and tightly sealed to the capsule 14, supports a double cellar gate 24 having a lower gate 25 and an upper gate 26. In accordance with the custom of the art, the cellar gate 25 is fitted with pipe rams (not shown), while the cellar gate 26 is fitted With blind rams (not shown). An annular preventer 27 is removably mounted on the double cellar gate 24, and an extension spool 28 extends upwardly from the top 29 of the preventer 27 for engagement with a drill-through blowout preventer 31.
The drill-through blowout preventer 31 comprises a lower stationary body portion 32 and an upper or stripper portion 33, also stationary. While drilling is in progress, the kelly 21 is slidably and rotatably attached to the stripper portion 33 and extends downwardly through the portion 32 for engagement with a drill pipe 34 which drives a drill bit (not shown) at its lower end.
In accordance with standard drilling practice, all of the blowout preventers, including any additional preventers mounted between the extension spool 28 and the preventer 31, are remotely controlled, and drill bits and casing are passed or locked through the preventers and into the floor of the sea.
Mud return is provided for in the usual manner by an emergency high-pressure outlet 35 on the wellhead 23 which communicates through a valve 36 with a high-- pressure mud-return line 37 and by a normal-pressureoutlet 38 on the preventer 31 which communicates through a valve 39 with the high-pressure mud-return line 37 to form a combined-pressure mud-return line 40.
A closure plate 41, which is sealed to a flange 42 on the vessel 10 by means of bolts 43 and annular packing 44, prevents the entry of seawater into the interior of the vessel 10 in the event that the seal established by means of the mechanism 16 between the vessel 10 and the capsule 14 becomes ineflective during the drilling operation. A first opening 45 in the plate 41 is fitted with a removable gland 46, which forms a slidable seal about the spool 28. A second opening 47. in the plate 41 is fitted with a removable gland 48, which forms a seal about the high-pressure mudreturn line 37. A manhole 49, the third and final opening in the plate 41, is provided with a cover 50, which is tightly .sealable about its periphery to the plate 41.
The watertight seal between the vessel- 10 and the capsule 14 is effected by a circular flange 42 on the vessel 10 and a. mating flange 51 on the capsule 14 which are wedded .by the mechanism 16 referred to above. The mechanism 16 includes a level 52 for turning a shaft 53 at the end of which a pinion 54 engages a ring gear or annulus 55. The annulus 55 has a dovetail circular tongue 56 which fits within a dovetail circular groove 57 in the bottom of the vessel 10 so that the annulus can be freely rotated. When the annulus 55 is rotated, spaced-apart inwardly projecting lips 58 on the annulus engage spaced-apart. outwardly projecting lips 59 formed around the circum-- ference of the flange 51. The. lips '58 and 59 are inclined.
to form portions of helices, so that the vessel 10 and capsule 14 are drawn tightly together when the annulus 55 is rotated in one direction and are disengaged from each other when the annulus is rotated in the opposite direction. Suitably placed packing or gaskets at 60, '61 and 62 ensure a watertight seal. A collar 63 on the shaft'53 maintains the vertical position of the shaft regardless of the pressure of the sea.
Thus it will be seen that drilling can be conveniently accomplished from the submerged vessel by personnel who are not subjected to the hazards of working while exposed to the great pressures which prevail in the ocean depths.
After the drilling of the Well is completed the welldrilling equipment is removed from the capsule 14, well production equipment is put in place, a hatch 64 is put onto the capsule 14, and the vessel 10 withdraws; see FIG. 3. The cementing of the casing 17 may be accomplished in a conventional manner.
The well completion equipment illustrated in FIG. 3 includes a Christmas tree 65 which has one or more master valves 66 and wing connections 67 and 68 which pass sealably through the capsule 14 for the delivery of oil. Wing valves 69 and 70, respectively, control the flow of oil through the wing connections 67 and 68 and sea valves 71 and 72 so that either of the wing connections can be closed off to facilitate the making of repairs.
The watertight integrity of the capsule 14 in the vicinity of the hatch 64 is maintained by a circular sealing flange 73 on the hatch which mates with the sealing flange 51 on the capsule. The flanges are locked together by means of a wheel 74 which rotates a shaft 75 connected to rods 76. When the wheel 74 is turned the rods 76 are rotated about the axis of the shaft 75 so that their outer ends fit into slots 77. The slots 77 are inclined to form portions of helices, so that the hatch 64 and capsule 14 are drawn tightly together when the wheel 74 is rotated in one direction and are disengaged from each other when the wheel is rotated in the opposite direction. Packing 78 ensures a watertight seal. See also FIG. 4, which is a plan of the capsule 14 and hatch 64.
A downhaul cable 79, illustrated in FIGS. 3 and 5, extends vertically from the hatch 64 to the surface of the water, where it may be secured to a float (not shown) indicating the position of the well. The float may be distinctively marked to identify a particular well in a field. Alternatively, a transponder 79a on the capsule 14 may be used for this purpose. The transponder 79a may be coded to transmit an identifying signal on demand.
FIG. 5 ShOWs a service chamber 80 guided in its descent from a tender 81 to the capsule 14 by the downhaul cable 79, which is taken up within the chamber 80 on a cable reel 82 (see FIG. 6). Cables 83 include air supply and exhaust hoses and light and communications lines. Anchor chains 84 and 85 hold the tender 81 in position during the descent of the chamber 80 (FIG. 5).
When the chamber 80 reaches the capsule 14, (FIG. 6) it is guided by the downhaul cable 79 and the lugs 18 so that it is properly oriented with respect to the capsule 14. A gasket 86 corresponding to the gasket 62 on the vessel 10 is compressed by the chamber 80 to form a temporary seal.
In FIG. '6 the chamber 80 is illustrated in position on top of the capsule 14. The chamber 80 comprises an upper compartment 87 and a lower compartment 88 divided by a deck 89. The upper compartment 87 is of a watertight construction, while the lower compartment 88 has a diving bell configuration: That is, it is enclosed on the top and around the sides but open at the bottom during the descent of the chamber 80.
The personnel who are to effect repairs within the capsule 14 make the descent in the compartment 87 (to which they gain access through an upper hatch 90 while the chamber 80 is on the surface) and are accordingly exposed to a pressure of only one atmosphere. The compartment 88 admits water at the bottom as the chamber 80 makes the descent. The water is, of course, unable to rise completely to the top of the compartment 88 but compresses into the upper portion thereof the air trapped therein, keeping it always at the pressure of the water 6 at the depth at which the chamber happens to be located.
A pump 91 is provided to expel the water from the compartment 88 through a valve 92 and into the sea after the chamber 80 is seated on the capsule 14. The air trapped within the compartment 88 simultaneously expands and fills all of the compartment except the part thereof which is now occupied by the upper portion of the capsule 14. Thus, with the removal of the water from the compartment 88, the pressure within the compartment is reduced to little more than one atmosphere. Venting the lower compartment 88 to the upper compartment 87 equalizes the pressures in the two compartments.
If the chamber 80 is accidentally tipped while being lowered into the Water, so that the compartment 88 prematurely fills with water, air is admitted into the compartment 88 after a temporary seal has been established between the chamber 80 and the capsule 14 by means of the packing 86 and during the time when the Water in the compartment 88 is being pumped out into the sea in order to fill the vacuum which is created in the compartment 88 upon the removal of the water. The air to fill the vacuum is supplied from the compartment 87 or tanks (not shown) of compressed air.
After the pressure in compartment 88 has been brought to the proper level, a hatch 94 in the deck 89 may safely be opened by means of a block-and-tackle 95, and the personnel within the compartment 87 may descend into the compartment 88. Here they may complete the formation of a watertight seal between a circular flange 96 (identical to the flange 42 on the vessel 10) and the flange 51 by means of a mechanism 97 (identical to the mechanism 16 on the vessel 10) in the manner described above, open the hatch 64 and descend into the capsule 14 for the purpose of making an inspection or etfecting repairs. Upon completion of the inspection or repairs they may reenter the compartment 88, replace the hatch 64 on the capsule 14, break the seal between the flanges 96 and 51 by means of the mechanism 97, re-enter the compartment 87, replace the hatch 94 in the deck 89, admit water into the compartment 88 to raise the pressure therein, and signal the personnel on the tender 81 that the chamber 80 is returning to the surface. A cable 98 is reeled in as the chamber 80 rises.
Second embodiment: Drilling at well in shallow water FIGS. 7 through 13 illustrate an embodiment of the invention particularly adapted for use in drilling, completing and producing from a well in shallow waters. Water is deemed to be shallow for present purposes when drilling may be accomplished from a platform which is mounted on a floor underlying water but which extends above the waters surface.
FIG. 7 shows means for lowering casing into an underwater well. A conductor pipe 100 has been driven by conventional means into the floor of the sea to the point of refusal in preparation for drilling a well. An anchor pad 101, having casing-means-receiving means such as a center hole 102 large enough to pass over the conductor pipe 100, is lowered about the conductor pipe 100 in concentric relation thereto. Elongated guide means such as guide cables 103 attached to the anchor pad 101 on opposite sides of the hole 102 by conventional releasable end fittings 104 extend upwardly to a drilling rig (not shown) on the surface of the water. The drilling rig may be a conventional rig mounted on a platform resting on the bottom of the sea and rising above the waters surface.
A hole or well is drilled to a desired depth (which may be a thousand feet or so) below the lower end of the conductor pipe 100, so that the hole 102 is aligned with the well, and the conductor pipe 100 is then severed in the vicinity of the pad 101 at, say, a point 105, the upper portion being withdrawn to the drilling rig, where it may be stored for later use on another Well. A capsule-support casing 107 also carried aboard the drilling rig is then