U.S. patent number 3,738,434 [Application Number 05/105,434] was granted by the patent office on 1973-06-12 for the apparatus and method to establish and sustain a subaqueous strata drilling system.
Invention is credited to Arthur John Nelson.
United States Patent |
3,738,434 |
Nelson |
June 12, 1973 |
THE APPARATUS AND METHOD TO ESTABLISH AND SUSTAIN A SUBAQUEOUS
STRATA DRILLING SYSTEM
Abstract
The attended drilling system comprises a vertical array of
objects without the conventional conductor pipe extending from
floor to surface of a body of water to encase the drill string. The
principal contributing objects of the array considered in the
present application comprises: a drilling station that is to be
established upon the floor, a control station stably maintained at
the surface and a support station adapted to function between as an
elevator. These stations are transported to a site upon a barge
adapted to the method of drydock handling of buoyant vessels. Means
to sectionalize the drilling station to permit variations to its
assembly and the relocation of the portable sections minimizes lost
time. Adjusting, monitoring and control means are provided and
constructed to function in a prolonged underwater environment.
Inventors: |
Nelson; Arthur John (San Mateo,
CA) |
Family
ID: |
22305825 |
Appl.
No.: |
05/105,434 |
Filed: |
January 11, 1971 |
Current U.S.
Class: |
175/6; 166/355;
166/358 |
Current CPC
Class: |
E21B
7/124 (20130101); E21B 19/09 (20130101) |
Current International
Class: |
E21B
7/12 (20060101); E21B 19/00 (20060101); E21B
7/124 (20060101); E21B 19/09 (20060101); E21b
007/12 (); E21c 019/00 () |
Field of
Search: |
;175/6,8,9 ;166/.5,.6
;114/236 ;61/69,46 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Champion; Marvin A.
Assistant Examiner: Favreau; Richard E.
Claims
What is claimed is:
1. In a system to establish a vertical array of assembled objects
in cooperating arrangement with a surface service station to
automatically and uninterruptedly bore a hole in subaqueous strata
with an integral drill string of a length commensurate with the
array extending from the surface to the floor of a body of water
said string having a drill bit at its lower end with the array
comprising:
a. an elongated first member formed with a buoyant chamber to
supplement support established on the floor for transmitting torque
to rotate the string;
b. a second member for buoyant support of the drill string to
selectively control bearing pressure of the drill bit upon said
strata;
c. an elongated third member comprising the following
components;
1. immersed buoys to provide compensating support for this third
member respective said surface;
2. a conduit for fluid communicating relationship between said
service station and said drill string; and,
d. flexible elements adjustably interconnecting the three members
conveys means for coordinating control of the said bearing pressure
and descent of the integral drill string and conduit corresponding
to progress in boring said hole;
the improvement comprising:
1. a barge is adapted with chocks fitted to the deck to accommodate
mounting said first, second and third members to safely convey the
assembled array to and from situations;
2. said barge is sectionalized into independently buoyant portions
selectively locked together as a unit, having an end section in
support of said first member, a mid section with vertical well
formed in it for passage therethrough of the said second member
supported therewith and another end section in support of said
third member;
3. said third member overhanging the deck is disposed to employ its
buoys as outrigger buoyant support to the stability of the barge
bearing the elongated first and third members comprising the barge
deck load;
4. the end sections pivotally hinged to the mid section by equal
length parallel mounted linkage permit selective vertical
displacement of either end section while retaining parallelism of
the planes of the three decks;
5. an arrangement to establish and maintain freeboard and trim of
the barge comprises a ballast system regulating the exchange of
water to and from the holds of said sections with the hold of each
said section compartmentized by partitions penetrated by small
holes to provide common fluid communication yet avoids horizontal
surging of water introduced;
6. the deck of the end sections are immersible to enable said
buoyant chambers and buoys associated with the first and third
members respectively to assume support of a then released member;
and,
7. said buoyant chambers are regulated through said interconnecting
flexible elements extending to said service station to afford
manipulation of said elongated members to or from the barge in
compliance with the displacement of an end section.
2. A system to establish a vertical array of assembled objects
supported in variable spaced relationship in a body of water having
an uppermost control station retained at the water surface in
buoyant support of a suspended rigid member and a load transmitted
by selectively extendable and retractable primary flexible members
tensioned by a support station likewise in buoyant support of a
suspended rigid member and a load transmitted by selectively
extendable and retractable secondary flexible members tensioned by
a drilling station established to a stable and erect posture as
monitored by a leveling device employed to monitor and control the
support of the drilling station upon the ungraded floor below, the
improvement comprising:
a. said drilling station has at least three supporting telescopic
legs each individually powered to a required length to establish
said erect posture as sensed by said leveling device monitoring and
controlling the adjustment of each leg to an extension providing
said posture;
b. said drilling station has a selectively variable volume gas
filled chamber common with each leg to contribute its buoyant
support to share the weight of the drill station as said volume
responds to said leveling device in control of a liquid level
controller adjustably contained in said chamber to regulate the
liquid level thereby controlling the buoyant support;
c. articulatively fitted feet to the legs are to be impressed into
the floor while said volume is temporarily minimized;
d. a stabilizing means for said stations comprises thrusters
monitored and controlled to exert a reactive force sufficient to
avoid oriented displacement and vertical misalignment between said
objects when actuated by said flexible members displaced from a
normal vertical disposition;
e. said drill station is touched down and erectly established to
the floor by an arrangement comprising, controlled payout of said
extendable members and rotary limit switches superiorly employed to
automatically limit the extent of movement of the legs being
adjusted in length; and,
f. an automatic monitoring means controls said selectively
extendable and retractable secondary flexible members to provide
adjustment to said flexible members commensurate with vertical and
spaced disposition of said rigid members.
3. A subaqueous strata drilling station, responsive to remote
control from a surfaced control station and a service station
therewith, to be automatically parted into a portable portion and a
stationary portion supported by legs bearing with the floor of a
body of water to an immersed position accommodating a diverter
assembly likewise adapted to be automatically parted into a top
section in sliding engagement with said portable portion and a
bottom section secured to a strata fixed surface well casing
concentric with the drilling station providing uninterrupted
torqued translation therethrough of an independently supported
drill string terminating with a drill bit to bore a well in said
strata, the improvement comprising:
a. a conduit system comprises, said diverter assembly accommodating
the fluid sealed passage of the operating drill string therethrough
and limiting fluid from the well to flow through a formed conduit
portion connected to a coupling fixed to said stationary portion
therewith to compensate for limited alternating vertical position
of a remote conduit assembly buoyantly supported for fluid
transmission to said surfaced service station;
b. said diverter assembly is journalled to the drilling station for
tolerable axial space relationship therewith accommodating
dimensional discrepancies between a member common to two
independent bases temporarily engaged upon removal of said portable
portion and top section from said stationary portion and bottom
section respectively;
c. said drilling station is remotely and selectively separable into
a stationary portion designated as the receptive permanent fixture
to the floor and the upper superstructure formed portable portion
optionally disposed to divest the well of the drill string with the
top section of the diverter assembly;
d. said drill station is sustained to an erect posture and stable
position by a support means comprising, a pontoon formed integral
with the portable portion and individually powered and adjustable
telescopic legs extending as foundations for said stationary
portion to firm footing with the floor;
e. antirotational means applied during descent of the portable
portion for correct oriented reengagement with the stationary
portion comprises, said portable portion bears protrudences for
slid-ing bearing with the sloping contour of said receptive
permanent fixture to provide guided return of the portable portion
to re-engage cooperating members between said portions comprising
matching gears selectively employed to transmit said same power to
said legs as dually adapted also to power said drill string;
and,
f. the drilling station support means further comprises, said
pontoon formed into compartments provide an adjustable gas volume
for each of at least three said legs for mutual support of the
drilling station with each automatically responsive to a leveling
device sensing said erect posture for selective monitoring and
controlling both said individually powered legs and a liquid level
controller adjustably contained in said chamber adapted to regulate
the gas volume therein.
4. A drilling station according to claim 3, wherein said remote
conduit extends from the surfaced service station as a vertical
array supported by buoyant means permitting axial surging of the
conduit and is connected through a compensating coupling by a
formed conduit portion to said diverter assembly, the improvement
comprising:
a. an accommodating housing provides for the central location
thereto of the terminal of the formed conduit portion connected at
the central horizontal axes and to one end of the accommodating
housing;
b. an end cover rotatably fitted to and enclosing said
accommodating housing provides for the connection of said remote
conduit with inlet axis offset and parallel to said horizontal
axis;
c. an offset fitting provides fluid communication between said
formed and remote conduits with fluid tight journal-like fit
therebetween and within said accommodating housing;
d. said offset fitting pivots about said horizontal axis through an
arc defining a lower and upper remote conduit inlet position as
sustained by the rotatability of said cover to accommodate said
surges; and,
e. a supply of lubricant for said journal fits in pressure balance
with that of the fluid transported through the coupling.
5. A drilling station according to claim 3, wherein the bottom
section of the diverter assembly is dominated by at least one
blow-out preventor manipulated by a remote control system integral
with the said remote conduit to selectively seal off the well at
any time with or without removal of the drill string, said top
section of the diverter further comprises:
a. joined cylindrical bodies provide a first stagnant chamber
established between said blow-out preventor and a partition
supporting a throttle assembly accommodating passage therethrough
of the drill string with close annulus clearance and at least one
transition chamber serially established thereabove by addition of
like partitions and throttle assemblies for each, all in space
relationship in excess of the coupling length joining tubing
segments of the drill string;
b. a sealing means, operatively incorporated with a partition
establishes the uppermost transition chamber to provide said fluid
sealed passage of the drill string with close fit to said
segments;
c. all said throttle assemblies and the sealing assembly are split
axially into halves movable to and from the drill string segments
to provide an open passageway for said couplings between chambers;
and,
d. a power means connected to each of the halves are serially
operated to pass a coupling and means urge the halves together
before another throttle assembly is parted.
6. A drillinG station according to claim 5, wherein the said close
annulus clearance restricts leakage flow from the well to the said
serially disposed chambers, the improvement comprising:
a. an external bypass effected around each throttle assembly
transmits said leakage back to a transition chamber beneath from
which it escaped; and,
b. said transmission of leakage further comprises, the drainage of
leakage flow from a transition chamber to a sump for ejection
therefrom by an extension of the gas volume control system for the
drilling station.
7. A drilling station according to claim 5, wherein said
independently supported drill string suspends from a thrust bearing
mounted on a buoyant support station stabilized for controlled
vertical travel to feed the drill string bit into the strata below
the drilling station as revealed by flexible members adjustable
interconnected as taut wires between the two stations, the
improvement comprising:
a. a wire length adjustment means periodically spools said wires,
to retain a limited store of wire, corresponding to change in
elevation of the support station above the drilling station;
b. a weighted sheave establishes said taut wires as supported in
the loop developed in the return of a wire on itself to accommodate
the change of accumulated wire responsive with movement of the
support station with the store of wire trained below said
adjustment means;
c. said periodic spooling transfers a wire length commensurate with
the span of equally spaced said couplings and effects the vertical
travel of the sheave in a distance measurably one half of said
span;
d. said sheave is correlated with couplings of the string to
reciprocatingly return once to a specific position coincident with
the imminent position of each coupling to said diverter assembly;
and,
e. monitoring means intercepted with vertical travel of said sheave
for control of said throttle assemblies comprises, said
interception activates magnetic switches regulating each throttle
assembly sequentially to provide said passage of a coupling with
each incidence when confronting a throttle assembly or the sealing
assembly.
Description
LEGEND
Symbol Reference Dated Inventor Ref. A Pat. No. 3,593,808 8-20 -71
A. J. Nelson Ref. B Ser. No. 63,507 8- 13-70 " Ref. C Pat. No.
3,570,815 3-16-71 " Ref. D Pat. No. 3,359,741 12-26-67 " Ref. E
Pat. No. 3,336,895 8-22-67 " Ref. F Pat. No. 3,526,097 9-1-70 "
CORRELATION OF APPLICATIONS
The present application is a further supplement to Ref. A in above
legend. As provided in that disclosure the method depended upon
three separate stations retained in vertical alignment as
contributing factors to prolong uninterrupted drilling of a hole in
the ocean floor. A subsequent application, Ref. B, covers in detail
various means obviating the need of the conventional conductor
pipe, discloses variations to achieve the basic principle and
introduces necessary intermediate phases with drilling to sustain
the improvement in drilling progress. The present application
discloses: means for handling the apparatus with regards conveyance
to and establishing the site, facilities to remotely accomplish
adjustments, variations to the assembly and particulars concerning
protective measures in contention with environmental conditions
affecting members immersed for extended periods of time. Ref. A, B,
C, mutually dependent upon the other, and individually contend with
a particular aspect of the entire system.
BACKGROUND OF THE INVENTION
As disclosed in the aforementioned applications advantage is taken
of the `space` available with deep water to preassemble a drill
string to an integral length which together with the torque and
feed means provides an extended time of drilling not feasible with
conventional apparatus. To further this effectiveness, the
multiplicity of segments comprising the integral length is
minimized; so that fewer time consuming connections are required in
the assembly. Consequently, each replaceable segment itself is of
considerable length requiring corresponding extended apparatus to
accommodate them. Limited integrity of a bored hole dictates the
need to line the hole with a casing, necessitating removal of
obstructions to their placement.
The omission of the conductor pipe also normally used as a
conveyance tube for transfer of materials through the body of water
necessitates a substitute means such as the diverter to control the
well.
The automatic and continuously effective torque means is dependent
upon a control system monitored by means subject to long immersion
and detrimental effects by not only the well fluid but also by
environmental conditions.
The establishment of an erect station to the floor must be
sustained in contention with erosion of the floor supporting the
station.
Accordingly it is a principal object of the present application to
provide those features insuring continuous drilling and to provide
means by which the establishment and servicing of apparatus is
effective.
A prime object contends with the handling of apparatus not feasibly
manipulated by cranes and the like.
A further object is to minimize the makeup of connections so that
shop assemblies eliminates many arduous tasks otherwise undertaken
under more trying conditions.
A still further purpose is to provide means enabling removal and
replacement of components of the assembly in contention with forces
acting on the extended assembly in reach to the floor.
A further object is to insure the continuous performance of
remotely operated control means subject to adverse environmental
effects.
SUMMARY
This application is concerned first with the conveyance, handling
and establishing of a specific form of a subaqueous strata drilling
apparatus that has been extensively adapted to prolong penetration
of that strata. The primary structures of the vertical array of
that apparatus are transported aboard a common carrier and the
sequence of their discharge permits interconnecting flexible
members to remain intact. To effect the discharge the carrier
sectionally assimilates a floating drydock in the handling of those
structures as buoyant vessels relying on operational control means
to assist manipulation of the various objects from an `aboard`
position to operating condition. The service station attending the
vertical array is introduced to make up the drill string to the
anticipated integrated length prior to placement of the drill
station to the floor, thereafter assists in the establishment of
the apparatus and finally becomes inclusive with it.
Secondly, this application proposes sectionalizing the drill
station to provide a permanent portion that facilitates re-entry
into the hole of assemblies with needed modification to stepwise
accommodate various phases of the operation to the completion of
the well.
Thirdly, insurance is provided for the continued performance of the
apparatus by the mode of operation and protective features employed
to contend with not only "well" conditions but environmental
liabilities.
This application therefore discloses means for establishment of the
apparatus and means improving performance and continuance in
operation.
The term `continuous drilling` is predicated upon the space between
the surfaced control station and the remote drilling station below
that permits lowering therebetween of the support station as a
regulated elevator of the preassembled drill string retained as an
integral length through that descent.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is an elevational view diagrammatically illustrating the
assembly having performed a drilling operation and in which a
conveyance 600 is immediate to the control station 34.
FIG. 2 is a partial elevational view diagrammatically illustrating
the initial assembly of the drilling station 150a in the process of
being lowered to the floor where it is to be established.
FIG. 3 is a partial elevational view illustrating the drilling
station 150a with the base portion 154a fixed to the floor and
portable superstructure portion 156a thereof separated as would be
during a servicing operation.
FIG. 5 is an enlarged elevational view with parts broken away of
the drilling station 150a.
FIG. 7 is a sectional elevational view with parts broken away
showing construction of joint 50a.
FIG. 8 is a schematic diagram of the antirotational means taken
from FIG. 6.
FIG. 20 is a sectional elevational view of an alternate sealing
arrangement to that of the shuttle mechanism 357 of Ref. B.
FIG. 6 is a plan view with parts broken away of FIG. 5.
FIG. 21 is an elevational view of the diverter assembly 348.
FIG. 17 is a sectional elevational view with parts broken away
showing construction of the throttle mechanism 363a incorporated in
the diverter assembly 348.
FIG. 9 is a diagram expanding on the control to include
establishing the drill station at the floor.
FIG. 4 is a partial elevational view illustrating the first
supplementary operation to drilling having bored the upper hole
portion.
FIG. 18 is an elevational view of the apparatus in the process of
being modified while attending to supplementary phases to the
drilling operation.
FIG. 16 is a sectional elevational view illustrating an assembly of
apparatus housed for protection against the environment.
FIG. 14 is a sectional elevational view illustrating an assembly of
apparatus housed for protection against the environment.
FIG. 19 is an end view typical of the cam operated switch as part
of the selsyn assembly of FIG. 14.
FIG. 15 is a sectional view showing means to protect members
immersed in a liquid.
FIG. 13 is a schematic diagram of controls associated with
adjustably positioned members.
FIG. 22 is a partial elevational view of drilling apparatus aboard
a conveyance.
FIG. 24 is a plan view of FIG. 22.
FIG. 10 is a sectional view of a compensating means 643 for
coupling the oscillating conduit 362 to the fixed portion 154a of
the drilling station taken from 47--47 of FIG. 11.
FIG. 11 is an end view of FIG. 10 taken from 48--48.
FIG. 12 is an elevational view schematically illustrating operation
of the compensating means 643.
FIG. 23 is a diagramatic illustration of one type of ballast
control for the barge 600.
DESCRIPTION
The procedure concerned with handling the apparatus from aboard a
conveyance, through the various stages establishing the array and
intermediate steps in servicing the system is presented first in a
general discussion to be followed with detailed particulars of
pertinent apparatus thus far deferred or modified from the
references.
See FIGS. 1, 22, 24. A barge 600 preferably as for Ref. E is used
between situations to convey the three stations employed in the
vertical array, namely: drilling station 150a to be established at
the floor 152 of a body of water, the support station 52a monitored
to feed the drill string into the floor and the control station 34
partially submerged at the water surface 28. Unloading from the
barge is to be in this stated sequence as required by flexible
lines retained intact between them as represented by phantom lines
99a, 99b. This discharge is manipulated without use of a crane or
the like, though the barge may be so fitted for other purposes.
The barge 600 is sectionalized (as arbitrarily shown) having a
foresection 601, an aftsection 602 and a midsection 603; the three
sections hinged together by sets of equal length parallel mounted
linkage 604. Either fore or aft section is free upon release of
locks 605 (as shown in phantom view for the foresection) to be
displaced from an aligned position of the three sections. Such
displacement is controlled by any suitable ballast system that
regulates buoyant support of a selected section by introducing or
removing water to its hold. The hold interior is partitioned as by
ribs 606 that are penetrated by small holes to provide common fluid
communication among all yet avoids horizOntal surging of the
confined water. Suitable chockS 607 that are permanent to the deck
are contrived to grip the supported structures 34, 150a, and are
remotely controlled to be selectively operable. The midsection 603
has a well 608 formed through it accommodating passage of support
station 52a from an above water storage position to an immersed
condition as manipulated by jacks 609. It will be observed in FIG.
24 that structures overhang the barge and in the case of
superstructure 34 by a considerable amount. In this case its buoys
40 actually contribute to the stability of the floating mass by the
outrigger effect, noting structure 34 is last-off first-on the
barge.
Upon arrival at a site service station 20a is brought alongside
barge 600; so as to be made up to the feed end of terminal for the
intact flexible members represented by lines 99a, 99b, to provide
the means to manipulate various controls as assistance in
discharging and establishing the array. Meanwhile selected locks
605 are freed to release the aft section 602 supporting the drill
station 150a, then still held in position because of its buoyant
capacity slightly in excess of its aggregate weight (as will occur
for the forward section indicating the midsection contributes less
support than its aggregate weight). By adding ballast to section
602 the mass is made to part from bearing to the midsection and by
the parallel linkage descend with retention of the plane of the
deck parallel to that of the rest of the barge. The aft deck
becomes immersed with continued controlled feed of ballast to
gradually bring the pontoon 620 of the drill station into play as
the buoyant support means as in FIG. 3b. At some point a supply of
baffle fluid 482 introduced to chamber 481 confined above port 480
will be displaced upwards by entry of water past foot valve 480a to
a predetermined level fixed by structure 500 as disclosed in Ref.
B.
Trim of the barge 600 is maintained while simultaneously
diminishing its freeboard; so as to bring the deck of the aft
section below the free floating position of station 150a. When that
position has been reached the chocks are freed whereupon the
buoyancy of pontoons 620 are increased while that of hold of
section 602 is decreased. The pontoon 620 gradually takes over
support of its structure to part from the deck, then to be cleared
free of the barge.
Incidentally as seen in FIG. 24, the preferred barge of Ref. E
utilizes a steering cable system 610 to actuate rudders 611 in
steering the towed barge when deviating off course set by the
towing tug. This steering cable is released from its operative
condition by jack-knife operating comalongs 612 (schematically
shown) to provide the necessary cable extension when the sections
601, 602 are displaced. This wire is also detachable at coupling
613 so that drill string 146 is unconfined in alleyway 614 through
which it has been extended. It is to be noted that the weighted
drill bit serves as a keel towards stabilizing the drill station
when freed off the barge and not yet controlled by wires 99a.
See FIG. 18. Service station 20a is then employed to make up the
drill string length to the required extension of the lowest segment
included in the station assembly and bearing the bit as exemplified
in FIG. 2b. Derrick 26 is complimented with portable platform 615
that bears a clamp means 77a similar to that of clamp 77 of Ref. B
to assist in the make up or dismantling of circuit 46 with surplus
segments stored aboard the service station 20a. Prior to completion
of the string assembly, the support station 52a is lowered below
barge 600 and floated to position adjacent platform 615 for
eventual positioning concentric to the completed string thereafter
elevated above station 52a whereupon fitting 50a is connected by
coupling 148a to the string. Finally the completed string is
lowered for engagement by automatic clamping means 616 of FIG. 7 to
station 52a now in support of the string. Hereafter platform 615 is
removed to storage.
The removal of control station 34 off barge 600 will have been
previously undertaken employing the practice for removal of the
drilling station; noting the flexible members represented by line
99b likewise pass down through the well 608 as attached to station
52a to extend up the outside of barge 600 to the terminal at the
structure 34. Control station 34 is centered above the lowered
array thus far assembled, whereupon the system is operated for
controlled lowering to establish the drill string upon the floor.
FIG. 2 depicts this assembly noting the absence of the diverter
components 348 and conduit 46 since borings of the first short
portion of the hole are washed to waste by a supply of water
introduced by conduit 84 having plugged off coupling 74 seen in
FIG. 7.
In FIGS. 5, 9, the erect posture and stable position of the drill
station 150a is obtained by means of leveling device 248 in control
of individually powered legs 182 as developed in Ref. A and B to
include impressing the feet 628 into the floor under maximum dead
weight by minimizing support by the pontoon chamber 620 and
thereafter relieving the load on the legs to buoyantly support a
share of the weight. The telescopic leg portion 186 terminates with
the foot 628 universally mounted and preferrably has three toes to
which pads are flexibly joined so that the gross bearing area of
the foot is deployed into smaller units more widely dispersed to
contend more effectively with uneven terrain. As previously covered
in Ref. A and B leveling device 248 is used to stabilize the
drilling station and with reengagement of gears 244, 246 with
return of portable portion 156a in subsequent operations the legs
are always controllable to correct any list from the desired
station posture. FIG. 31a furthermore discloses the effectiveness
of rotary limit switch 209 to automatically limit the extent of
movement of leg assembly 182 with remote warning (not shown) to
reveal such condition.
In FIG. 6 a reference centerline extending through the saddle 642
divides the plan view into symmetrical halves whereas the
perpendicular centerline to it divides the plan into non-uniform
halves with nonsymmetry arising from use of triple `leg` components
and a single remote conduit. A method is adopted to provide return
of members as withdrawn, so that a non-rotating means 296b is
employed to supplement stabilizing means included for support
station 52a and service station 20a as disclosed in Ref. A and B.
Such antirotational means permits descent of objects free of
concern of twisting the flexible members. Projecting this reference
centerline to the surface through the remote conduit 362
establishes proper orientation of subsequent transfer
operations.
By referring to FIG. 3 it is seen that drilling station 150a is
parted having removed the portable portion 156a from the stationary
portion. This premature viewing serves to illustrate a previous
first separation of the initial assembly represented by FIG. 2,
then leaving only a bare hole below the receptacle like station
154a. While the portable portion is remotely disposed for
rearrangement as needed for the following drilling operation, the
preassembly of FIG. 4 representing a portion of any other adaptable
assembly of Ref. B. (Ref. B) being lowered for temporary engagement
of mounting jig 617 to fit 618 of FIG. 5, thereby fixing the
position of surface casing 350 and bottom section 352 of diverter
assembly 348. Jig 617 with fixture 619 physically substitutes for
the pontoon 620 and top section 354 of the diverter assembly 348
and sustains the grouting-in operation as covered in Ref. B.
Thereafter the remotely operated clamps 356a are released so that
the assembly above flange 349 is then removed. What remains is that
lower fixed portion of FIG. 3 noting also that remote conduit
system 362 was established with the setting of assembly represented
as FIG. 4.
The upper portion of FIG. 3 schematically shows the appearance of
the portable portion 156a as reconditioned for re-entry to the well
to perform major extended boring operations and now fitted with the
top section 354 of the diverter assembly. As in FIG. 5 and 20
member 174a is adapted for sliding engagement 176a with the pontoon
620 so as to accommodate any minor axial dimensional difference
that would prevent the engagement of a member common to two
independent bases. As arranged clamps 164b and 356a will make up
automatically. A gap 622 is provided to discontinue fit 618 as a
full circle; so that formed conduit portion 358a is provided room
to nest between pontoon 620 and the receptacle like member 623.
Conduit 358a extends from the diverter 347 to a coupling 643
connected to conduit 362 providing fluid communication
therebetween. Coves 625 are formed in the periphery of pontoon 620
which completes free passage of the portable portion 156a from base
portion 154a avoiding interference with gear protrusions 246
extending within the receptacle 623. Shroud 627 guards these
protrusions comprising the adjustable leg driven gear 246 that is
re-engageable with gear 244, depending upon the mesh of these gears
as other separable means besides that at fit 618 and flange 349.
Though receptacle 623 will funnel the drill bit central to the
site, a pair of extending arms 629 redirect mounting of the
portable portion 156a in correct orientation by its sliding bearing
to deflector 630. These arms correct and stabilize the suspended
portion to prevent damage and align gears to mesh to reinstate
control of the fixed base portion that is subject to external
effects.
Again referring to FIG. 3 it will be observed that conduit 46 is
now included in the assembly having been made up per Ref. B as the
assembly is lowered. With first contact of the mating assemblies
phantom lines thereon depicts an off-center condition where
eventually arms 629 will have sliding bearing with the sloping
contour of deflector 630; finally squared by the short vertical
configuration 630a of deflector 630 which provides alignment of
fits and gears to engagement. When pontoon 620 seats in fit 618 the
upper diverter assembly 354 suspending in sliding fit 176a will be
displaced upwards by an established tolerance due to engagement of
flanges 349 to produce an assembly as depicted in FIG. 1. Meanwhile
during the final makeup of the drill station the conduit pivotal
portion 22 is connected to complete the fluid circuit that had been
temporarily displaced as in FIG. 18.
During the drilling operation station 52a will descend commensurate
with penetration of the strata to a lowermost position in vicinity
of the top 621 of tower 166; whereupon station 52a is raised to
retract the drill bit up clear of the preventer 353 which can then
be closed to seal off the well from the seas. Retracting of the
string is accomplished as discussed in Ref. B with regards
dismantling conduit 46 and a subsequent discussion of the automatic
operation of the diverter means 348 and the sealing assembly 357a
therein.
DETAILS
Barge 600
Sufficient discussion has covered this conveyance except for the
remotely controlled chocks 607. An adequate disclosure may be based
upon adopting the method to secure fitting 50a of FIG. 7. Thus each
of the chocks strategically positioned to support a structure would
provide a conical or taper mating of parts with spring loaded
locking jaws solenoid released.
In FIG. 23 a representative diagram illustrates a pneumatic system
for the control of ballast in the hold of the sections comprising
barge 600. This air supply may also be taken from the pneumatic
system on vessel 20a.
Drilling Station 150a
FIG. 5 is distinguishable from FIG. 3a in the rearrangement of
pontoon 620 now to be the base to which the tower structure 166 is
constructed. Thus the pontoon is part of the portable portion 156a
to enable various controls for it to be periodically inspected.
Controls to the lower portion 352 of diverter assembly 348 are
trained along the remote conduit 362 so remain with the permanent
portion of the installation.
Anti-rotational means 296b
See FIGS. 8, 6. The torque tube 170a is supported within structure
166 by a lower journal 172 an upper journal 168 and an intermediate
thrust bearing 276. BearinG 168 is centered by a supporting spider
631 at the top 621 of structure 166 that provides clearance space
633 through which flexible members pass as illustrated by wires
100a, 102a, 104a. A concentric ring 634 free to turn above the
spider bears inwardly extending ferrules 635 for each of the said
wires and a vane 636 located with a normal mean position midway
between two magnetic switches 637 also supported by the spider. In
much the same way as disclosed for the means 296 the taut wires are
relied on when twisted to rotatably displace the vane 636 to an
extreme position when either switch 637 is activated to actuate a
motor 638 driving pump 639 and open the corresponding solenoid
valve 640 to provide a fluid jet discharge from one of two nozzles
641 to establish a reaction to the force causing the displacement.
The arms 629 serve the dual function of transmitting fluid to the
nozzle located at their extremities, advantageously acquiring the
needed torque with least energy. It is anticipated this device may
also employ the leverage principle of Ref. B, so that with the
slightest twist of the station 150a during descent to the floor it
is instantly corrected.
Compensating Coupling 643 See FIGS. 10, 11, 12.
The remote conduit 362 buoyantly supported is connected to formed
conduit portion 358a that is fixed to solidly established drilling
station 150a. The necessary compensation of relative motion between
the two conduits is effected by this coupling 643 which is
supported in saddle 642 provided at the periphery of receptacle
623. The fixed conduit 358a is terminated with a first horizontal
axis member 644 centrally located to the axis of an accommodating
housing 645 that also shrouds a second horizontal axis member 646
disposed at a substantial space from the first member to form the
lower terminal of conduit 362. The members 644, 646 are identical
and their axis established parallel having member 644 journalled at
bearing 648 free to rotate about an axis common to the centerline
of housing 645 whereas member 646 is journalled at bearing 648 in
the end cover 649 enclosing the housing 645 to establish the said
spacing of axis. End cover 649 is supported in groove means 650
formed in housing 645 for free rotating fit therein; so that member
646 is free to revolve about the axis of housing 645.
Each of the members 644, 646 is encompassed by a cylindrical
housing 647 that is free to rotate about the common axis as
supported by distributed bearings 652. The two cylindrical housings
are flanged together by an interconnecting s type fitting 653 which
established their longitudinal spacing in housing 645 to provide
suitable end clearance 654. Split retaining rings 655 prevent the
endwise separatiOn of means 644, 646 whereas shoulders 656 butt to
the flanges of s fitting 653 to resist their inward
displacement.
A substantial volume of a lubricant is contained in a bellows type
reservoir 657 that is mounted within a pressure tight tank 658 to
provide lubricant for the bearings 652 via flexible tubing 659.
Tubing 660 establishes a balance of pressure for the injected
lubricant to that of the conduit system pressures.
As seen in the schematic view FIG. 12 the conduit 362 has
alternating vertical positions where its lower terminal 646 assumes
some position a then a lower position b, possible because of the
provided rotatable end cover 649. Since the conduit 362 remains
perpendicular though displaced horizontally, the journal 648 is
required as the connection to the cover. It is observed that no
such movement occurs between conduits 358a and housing 645
therefore member 644 could have been made fixed; but as arranged
they are more economical, being exchangeable. As seen in the end
view FIG. 11 the vertical displacement of conduit 362 from a to b
is obtained by pivot of s fitting 653 through the arc d--d.
Control of reels 118a
In FIG. 13. This schematic diagram illustrates monitoring means for
the actuation of reels 118a periodically employed to handle
flexible members as covered in Ref. B wherein one of several wires
102a is representative of the method to accumulate or store wire in
a loop fashion by means of a weighted sheave 272. Again briefly, a
motor 200 is clutched 208 to selectively power a turn table 202 or
leg 182. By an automatic monitoring means a second clutch means
208a is employed to mechanically transmit this power to operate
reels 118a as needed. To compensate for possible variations in
existing members a third clutch means 208b connects each of the
several reels to the common mechanical drive of the cluster of
reels. In this diagram sheave 272 is mounted in a carriage 661
guided for vertical travel between rails 662, 663 that terminate
with limiting lower stops 662a, 663a and limiting upper stops 662b,
663b. A pair of magnetic switches 664, 665 together with pivotal
vanes 666, 667 are also mounted on carriage 661. Arms 668, 669
extend as projected parts of the vane to be intercepted by the
stops for their pivotal displacement to a held position by any
suitable spring type clamps 670, 671.
Switch 664 monitors reel 118a during the drilling operation; so
that with descent of sheave 272 accounting for the accumulation of
wire as station 52a lowers to feed the drill bit into the strata,
the vane 666 is in displaced position (non-activating the switch)
represented by phantom view there imminent to the position of its
arms 668 being acted on by stop 662a. Such interference establishes
the vane 666 to a position activating switch 664 shown with
carriage 661 at some upward traveling position occasioned by the
now hauling-in of accumulated wire by reel 118a. Note clamp 670
stabilizes the vane to such position opposing the gravitational
effect of the extended arm 668 to displace the vane. With travel of
the sheave 272 dimensionally half of the length of cable hauled in,
the arm 668 is intercepted by the upper stop 662b so that switch
664 is then inactivated thus clutch means 208a discontinuing to
power reel 118a. Sheave 272 then repeats the downward travel for
accumulation of more cable until stop 662a again interferes.
As long as switch 672 is closed by spring 673 then magnetic switch
664 can be activated to control reel 118a, but by remote closing of
master switches 672b, 692a solenoid 674, 674a are powered to oppose
springs 673, 673a whereby switches 672, 672a are transferred to
make magnetic switch 665 effective to control reel 118a and reverse
the rotation of motor 200 when retracting the drill string. Thus to
raise station 52a to retract the string an accumulation of wire is
provided by payout of wire by reel 118a until sheave 272 is at a
lowermost position whereupon stop 663a interferes with arm 669 to
disengage clutch means 208a. Thereupon sheave 272 is raised with
raising of station 52a to an uppermost position where stop 663b
interferes with arm 669 to reactivate switch 665 to again power
reel 118a for further payout of wire and return of sheave 272 to
the lowermost position. It should be noted that the reels 118a are
geared to rotate at high speed to minimize the time in transferring
wire.
In FIG. 14. As provided in Ref. B, the sheave 272 was relied on to
activate a monitoring means to control crane motor 19 regulating
the elevation of frame 41 supporting conduit 46 in space relation
with fitting 50. Again chain 65 in FIG. 13 is so connected to
activate selsyn transmitter 61 for the remote operation of selsyn
receiver 49 attendding the crane. However, in FIG. 14 the sprocket
63 drives gearing 675 contained below a housing 676 enclosing thee
selsyn 61a and other apparatus associated with the operation of the
throttle system 363a. Housing 676 establishes a gaseous chamber 677
separated from the water body by a liquid baffle 678. A liquid
level controller 679 relying on the mercoid type electric contacts
similar to that of Ref. B monitors means associated with pontoon
620 to retain chamber 677 in balanced fluid communication via
conduit 680 also enclosing electric leads for makeup in chamber 481
of pontoon 620. A float type foot valve 681 is provided to retain
the supply of baffle fluid from escaping via the passageway 682 in
the floor of the housing providing transfer of water
therethrough.
In FIG. 16. A similar enclosure 683 provides protection of switches
664, 665 and appurtenances associated with their operation as
discussed covering FIG. 13. Enclosure 683 is shown with an
alternate arrangement omitting a floor when unconcerned in the loss
of the baffle fluid.
In FIG. 17 - 14
The throttle assembly 363a distinguishes in the removal of
monitoring and switch means from within the diverter cylindrical
portion 368 used to provide for the passage of couplings 148a past
throttle 367. Since as covered above movement of sheave 272 is
related to movement and length of string segments (spacing between
couplings) the monitor means 274b is relied on to serve a dual
purpose to include control of throttle 376. Accordingly, the shaft
684 of selsyn 61a is double extended to drive also a member of disc
cams with only two represented by 685, 686 that are caused to
rotate one turn for the total turns of sprocket 63 (resulting from
travel of sheave 272) through the reduction designed into exemplary
gearing 675, 675a. As in FIG. 19 cam 685 profile includes a
protrusion 687 which displaces vane plunger 689 to activate
magnetic switch 691 for the duration of time needed to pass
coupling 148a by expanded throttle 367 held open by the switch 691
manipulating solenoid valves 431-455 pneumatically controlling
power means 421. Ref. D is relied on for the system to establish
the gas pressure and volume requirements of the stations depending
upon byouant support, chambers, apparatus utilizing gas as a
protective environment, energy to operate associated power means
and the ejection of leakage in a bypass system. Similarly cam disc
685 with protruding profile 688 displaces vane plunger 690 to
inactivate switch 692 in control of motor 200 (otherwiSe shown as
switch 692b in FIG. 13); so that turn table 202 is idled. Thus
without centrifugal force, seal 402 opens for the time interval to
pass coupling 148a upwards without any interferences when
retracting the string. Again note the remote closing of switch 672b
as master control when withdrawing the string. The angular
magnitude of the protrusions 687, 688 and orientation with regards
the turn of shaft 684 conforms to provide a minimum allowance in
excess of that needed to effect the passage of the coupling.
In FIG. 20.
This sectional view of the upper portion of diverter assembly 348
shows the sliding fit 176a of bearing member 174a with pontoon 620
as previously covered and the substitution with sealing means 357a
for the shuttle mechanism 357 of Ref. B. Sealing means 357a
embodies all the features of throttle mechanism 363a of FIG. 17.
The two half portions 419a formed around the drill string 146 are
separable by power means 421 to provide passage through of the
couplings 148a and returned thereafter by spring means to reseal
the string. With this arrangement the stuffing-box sealing means
480a is relocated at bearing member 174a with the lower end of the
torque tube 170a now not including the coupling means 414-416 of
Ref. B.
Halves 419a bearing against internal ring flange 372a opposes
higher pressure of chamber 359b below and backs up the seal 402a in
contact with string 146. To make this seal more effective gland
halves 696 are free to be urged against seal 402a by the mentioned
pressure and retained in assembly with the parted halves of members
419a by dovetails 697. All of the power means are represented as
421 like that described for throttle 363a and actuated by a cam
disc and switch means of FIG. 19 stacked to shaft 684 within
chamber 677 of FIG. 14.
The position of sheave 272 is indexed with the descending couplings
148a when in imminent position to the seal 357a so as to be
approaching its lowermost position whereupon the cam 685 has been
rotated to have its protrudence 687 effective to cause the
expansion of seal 357a as explained. With continued descent of the
coupling subsequent throttles will pass the coupling until it is
disposed below all in the well, whereupon switch 664 is acted on to
cause reel 118a to haul in the accumulated wire. As covered in Ref.
A and B the torque tube 170a is arranged in length to enclose one
coupling at all times and as seen in FIG. 20 a coupling is in
imminent position with seal 357a when emerging from the tube 170a.
Thus the coupling then just entering the tube will be indicative of
the lower coupling position and acts with magnetic switch 197 to
close the circuit that will cause clutch means 208b to release reel
118a from the drive of gear 134a, if sheave 272 is higher than
should be. Switch 199 normally closed is included in the circuit
with switch 197 normally open and is positioned to be deflected
open when the sheave 272 is at the position when throttles shOuld
be attended. Thus the reel 118a can be released if the sheave 272
is higher than should be to pay out cable too with that still being
accumulated with descent of the coupling until the switch 199 is
inactivated with the apparatus in position as intended.
In the operative position with the throttle assembly 363a
restricting leakage between serially established chambers, the well
pressure in the stagnant chamber formed by the throttle assembly
immediately above the blow-out preventor dominating the bottom
sPction of the diverter is reduced substantially to ambient
pressure at the sealing assembly 357a by the pressure loss
occurring as frictional resistance to flow through each throttle.
Accumulation of leakage liquid within a chamber is avoided by a
bypass system permitting flow only as drainage from an upper
chamber to a sump 373 below, whereupon the accumulation within a
sump to a certain volume is monitored by a conventional liquid
level device to activate the pneumatic system extension of the gas
volume control at the drilling station to eject the draimed liquid
to a chamber below. When a throttle has been expanded to pass a
coupling as described, an excessive discharge of liquid accompanies
the coupling into an upper chamber which liquid is restrained
therein to nominal leakage past the closed throttle assembly
defining that chamber and to drainage to the sump as described. The
final chamber above the sealing assembly 357a dominated by the
elongated torque tube 170a is not subject to leakage fluid flow but
the discharge of well fluid into it with passage of a coupling
through the expanded seal assembly is again dispersed by the bypass
system.
In FIG. 15.
Switch 693 is exemplary of electrical devices immersed to great
depths and the means employed to adjust with pressure changes. A
network of pressure tight conduits 694 conveying electric leads are
in fluid intercommunication to a neighboring gaseous chamber
exposed to approximately the same environmental conditions and
already regulated to provide an environment free of deteriorating
effects of the sea in accordance with Ref. F. In this particular
switch of the magnetically actuated type, the reed-like contacts
are first encased in a gas filled capsule 698 to maintain its
operating clearances while being stabilized within a metallic
enclosure by a resilient material 699 and thereafter the capsule is
punctured; so as to subject said clearances with other voids to be
in balance with the controlled gaseous chamber.
SHALLOW WATER
As anticipated in previous coverage this drilling apparatus is
dependent upon the space provided by the depth of water to yield
protracted use of an integrated assembly. The overall performance
improves with increase in depth of water to the subaqueous strata.
In what is herein termed shallow water amounting to present day
maximum depth of `worked` waters the present invention is therefor
adapted to periodic lengthening of the string without resorting to
the system of divesting the well of the portable drill station and
well head. Such alternate method is considered to be within the
realm of the disclosure of Ref. B substantiated by the following
disclosure.
With reference to FIG. 7 it is considered obvious to modify the
arrangement by extending tubular support 138a above chamber 70 to
include the mounting of equalizer 106b, relocating the flange and
thrust bearing immediately thereabove and beneath seal 92. Thus the
remountable flange and thrust bearing secured by clamp 616 are
removable when the string has been retracted by raising the support
station 52a to its initial position below and in bearing with the
control station 34.
The same method is employed, as disclosed in Ref. B to sectionally
remove segments of conduit 46, to remove fitting 50a and segments
of string 146. Thereafter with a new drill bit the string is
reassembled with more segments to re-establish the drill bit to the
depth of hole penetration; so that support station 52a bearing
fitting 50a connected to the integral string is in uppermost
position with the control station 34 in support of a minimum number
of segments forming conduit 46 to be periodically lengthened with
progress in drilling.
CONCLUSION
From the foregoing description it is believed apparent that the
present invention enables the accomplishment of the objects
initially set forth herein. It seems apparent that the extent of
the present application justified treating it as a supplementary
application, deferring claims with this full disclosure of previous
concepts then necessarily included in briefest form to fulfill the
purpose.
* * * * *