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Publication numberUS3794125 A
Publication typeGrant
Publication dateFeb 26, 1974
Filing dateSep 7, 1971
Priority dateJan 11, 1971
Publication numberUS 3794125 A, US 3794125A, US-A-3794125, US3794125 A, US3794125A
InventorsNelson A
Original AssigneeNelson A
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Apparatus and method of maneuver and sustain
US 3794125 A
Abstract
The attended drilling system comprises a vertical array of objects extending from floor to surface of a body of water. 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 towed to a site as a close coupled self buoyant stable array, whereupon it is expanded and established as stated. Sectionalizing 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 to function in a prolonged underwater environment. A diverter, terminating the annulus defined by the drill string in a casing lined hole, accommodates fluid sealed axial movement of the string therethrough and provides fluid communication between said annulus and a conduit remote to the string. Said diverter is adaptable to drilling rigs employing the conventional kelly bar and draw works.
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Elite 1% States Patent- Nelson APPARATUS AND METHOD OF MANEUVER AND SUSTAIN [76] lnventor: Arthur John Nelson, San Mateo,

Calif.

[22] Filed: Sept. 7, 1971 [21] Appl. No.: 178,002

1 Related U.S. Application Data [63] Continuation-impart of Ser. No. 105,434, Jan. 11,

1971, Pat. No. 3,738,434.

[52] U.S. Cl. 175/6, 166/5 [51] Int. Cl E2lb 7/12 [58] Field of Search 175/6, 5, 7; 166/5, .6

[56] References Cited UNITED STATES PATENTS 3,353,364 11/1967 Blanding et al 175/6 X 3,456,745 7/1969 Peri 175/5 3,491,842 l/l970 Delacour.... 175/6 3,593,808 7/1971 Nelson 175/6 Primary ExaminerErnest R. Purser Assistant Examiner-Richard E. Favreau 5 7 ABSTRACT The attended drilling system comprises a vertical array of objects extending from floor to surface of a body of water. 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 towed to a site as a close coupled self buoyant stable array, whereupon it is expanded and established as stated. Sectionalizing 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 to function in a prolonged underwater environment. A diverter, terminating the annulus defined by the drill string in a casing lined hole, accommodates fluid sealed axial movement of the string therethrough and provides fluid communication between said annulus and a conduit remote to the string. Said diverter is adaptable to drilling rigs employing the conventional kelly bar and draw works.

9 Claims, 16 Drawing Figures mmmrm w Y 3.194.125

SHEET Q [If Fig1O 3:1 \55 ArthunlNelson PAT ENIED FE826 I974 SHEEI s or 6 ArthurJNelson APPARATUS AND METHOD OF MANEUVER AND SUSTAIN This application is a continuation in part of my previous application Ser. No. 105,434, filed .Ian. 11, 1971, now US. Pat. No. 3,738,434, issued June 12, 1973, identified below as Ref. D. Tabulated below are references of significance to the present application:

Symbol Reference Dated Ref A U.S. Pat. No. 3,593,808 issued 7-20-71 Ref B U.S. Pat. No. 3,722,584 issued 3-27-73 Ref C U.S. Pat. No. 3,667,252 issued 6-6-72 Ref D US. Pat. No. 3,738,434 issued 6-l2-73 Ref E Ser. No. 143,769 filed -l7-7l BACKGROUND OF THE INVENTION Conventional derricks limit the travel of the draw works with a corresponding operable kelly bar; thus not only during trips when a changeover is required, but also in drilling, the string must be stopped and hauled up to introduce another string segment with such frequency that liabilities are greatly multiplied. Dependence upon above surface apparatus to power equipment in reach through a body of water and into the strata below poses further liabilities.

Consequently, the present apparatus is employed in part to remove some of the liabilities of the conventional kelly driven string.

The apparatus developed according to the listed references above depends upon advantageous utilization of the situation of offset adversities.

Therefore a prime object of this application is to cope with the depth of water by utilizing buoyancy characteristics to provide extended support afforded by the depth as a superior draw works.

An important object, too, is to immerse the support means of the vertical array well below disrupting surface conditions, constructing surfaced members to contend with those adversities.

A further object is to expedite dismantling of the array when alterations or additions are required to the apparatus or well and facilitate relocation of the apparatus betweeen sites.

A still further object is to provide apparatus which not only automatically continues penetration of the strata over extended periods of time but is also in full control of the well against environmental adversities and dangers.

These and other objects of the inventionwill become more apparent when viewed in light of the following description and accompanying drawings.

SUMMARY OF THE INVENTION An apparatus arranged as a vertical array of buoyantly supported immersed members in a deep body of water to drill a well through the strata below by remote control from a surfaced vessel dependently linked to the array established as a stable assembly. The depth of water is advantageously utilized to prolong-drilling as a continuous operation commensurate with controlled descent of the support means of an integrated drill string preassembled to extend through the depth of water to lowermost penetration of the strata. This application is specifically directed to apparatus and method expediting alterations to the assembly and maneuvering from site to site of the compacted array as a towed body. Of the total assembled length of means employed to transmit drilling fluid to the bottom of a drilled hole, a length approximating three times the water depth of the site is retractable in three unit lengths.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is an elevational view diagrammatically illustrating unit removal of elements from the entire array upon completion of the drilling operation possible with the integrated assembly.

FIG. la is a fractional elevational view showing a method to alter the length of the array.

FIG. 2 is a partial elevational view illustrating a final phase in dismantling the array and displays separation of the drilling station.

FIG. 3 is a partial elevational view illustrating the array configuration upon completion of an assembly and prior to further progress in drilling.

FIG. 4 is an elevational view of the portable portion of the drilling station.

FIG. 5 is a partial sectional elevational view of the means to dismantle the drill string and the attending blow-out preventer.

FIG. 6 is a sectional elevation view of the universal joint.

FIG. 7 is a partial elevational view of the support station and related control station.

FIG. 8 is an elevational view diagrammatically illustrating unit composition of elements of the vertical array upon completion of the drilling operation possible with the integrated assembly.

FIG. 9 is a partial elevational view illustrating the array configuration providing access alley and means to dismantle the drill string and attending diverter. FIG. 10 is a partial sectional elevational view of the diverter means.

FIG. 11 is an elevational view of the diverter means in conjunction with use of the torque tube for an immersed drilling station.

FIG. 12 is an elevational view of the diverter means as employed with a drilling station using a kelly bar to torque the drill string.

FIG. 13 is an elevational view of a portion of a modified diverter showing how the drill bit is confined within prior to separation of the portable portion.

FIG. 14 is an elevational view of the diverter means as employed with a surfaced drilling station, and the diverter terminating an extended conductor pipe in reach through the body of water.

FIG. 15 is an elevational view of the diverter means and drilling station encapsuled in a water tight housing disposed somewhat below water surface.

The following is an abbreviated coverage of only the essential elements involved with the apparatus and methods relating to the purposes of the present application, depending upon the listed reference for a complete disclosure of the apparatus comprising the invention.

(In FIG. 1) A service station 20b floating on the surface 28 of a body of water provides transfer means, supplies and master control attending an array of objects stabilized and extending as a vertical arrangement for boring through the floor 152 of the body of water. The array, fixed to a site by an erect drilling station a bearing on the floor, extends to include control station 34a buoyantly supported by immersed pontoons 40 in vicinity of the surface 28 to define the extent of vertical movement of support station 5212 functioning between as a buoyantly manipulated feeder. The array further includes; drill string 146 preassembled to suspend from support station 52b as bared to the water in reach through the drill station and a diverter assembly 348 fixed to the floor, and a periodically lengthened conduit in fluid communication with the drill string extending therefrom upwardly with a vertical constituent 46 connected by flexible joint 38 to pivotal constituent 22 having the inlet end supported by axis 24 on the service station and adapted for connection to a fluid supply 701.

(In FIG. 6) A universal fitting 50b effects union of the non-rotating conduit 46 to the drill string 146 with the latter automatically and continuously rotated by the drilling station to effect uninterrupted penetration of the strata below the floor by the terminally connected bit 284.

(In FIG. 7) As part of the array, too, is a wire system comprising lower portion 990 connecting the drilling station 150a to the support station 52b and upper portion 99b connecting the control station 34a to the support station 52b joined by equalizers 106a, 106b respectively to the bottom and top of support station 52b to provide balanced tension in the three wires of its portion and the other wire ends are secured to reels. In addition to the preliminary function to tie the array together when in an inoperative position, the wire system also in transmitting a tension load provides taut members serving as an element in the stabilization system 296 and accommodation systems 274.

(In FIG. 7) The control station 34a includes a superstructure 36 transmitting the pontoon buoyant support to an apex assemblage 37 towering above the surface 28 to accommodate mounting of a crane 39 used to manipulate a frame 4] bearing; the flexible joint 38, unsupported end of pivotal constituent 22, all the vertical constituents 46 and reels ll8b for wire portion 99b locked during normal drilling to transmit a deliberate deficiency in the support of the drill string to the control station by way of the loaded crane 39. Thus the support station is insufficiently buoyed to avoid the contingency of buckling the conduit 46 if excessively supporting. Reels 1 18b provides wire length adjustment corresponding with length changes to conduit 46 and the crane 39 sustains movement of the conduit 46 by paying out cable to lower its tail block 55 consistent with penetration of the drill bit 284 in the strata below floor 152.

(In FIG. 1) The superstructure 36 is constructed upon a base 43 supported by the pontoons 40 connected at the vertices of a polygonal configuration dimensional in excess of the height to the apex 37. One of the lateral sides provides passageway 45 for articulative pivotal constituent 22 and assemblage of the array as to be subsequently discussed. The superstructure is provided with a leveler 47 arranged to retain the structure erect. Freeboard of the control station 34a is established by adjusting the position of a regulator 51 mounted to the superstructure at the desired mean water line. For normal drilling the superstructure is positioned to accommodate allowable movement of axis end 24 attributed to the heaving service station b as a surface vessel. When changes are made to the vertical constituent 46 while drilling, the superstructure freeboard may be al-- tered to better position for the assembly method to be subsequently discussed and previously covered in listed references.

(In FIG. 4) Reels 118a at the drilling station periodically haul-in the lower wire portion 99a with accommodation system 274 relating descent of the support station as progress in drilling to prescribe payout by the crane; so that the vertical conduit 46 descends accordingly to preserve a space relationship of its end within the fitting 50b. The lower wires, portion 99a, are provided with a weighted means to establish taut lines essential to the stabilizer system 296a. The weighted means being sheaves 272 guided for vertical movement representing half the descent of the support station 52!; to indicate progress in drilling. These sheaves provide a takeup means so that reels 118a need not be rotated except at periodic intervals when returning sheaves 272 from a lower limiting position to an upper limiting position with the limit switches touched-off communicating with the solenoid included in mechanism 208a transmitting power from the torque table to reels 118a.

(In FIG. 1) The flexible joint 38 connecting the conduit constituents 22, 46 moves vertically within the superstructure between a contracted position 73 of the tail block 55 and a lowermost clamped position 75 of the conduit 46 to the control station 34a, whereupon when so clamped the joint 38 may be disconnected from the conduit 46. The clamp mechanism 77 is integral with the bridge 79 extending between pontoons 40 and in its normal inactivated position provides clear passage through of the pipe segments 46a of the conduit 46 but intercepts couplings 48 connecting adjacent segments 46a. With the coupling engaged to the normal intercepting position of the clamp the conduit can no longer lower except as will occur with lowering of the control station 34a. Means are included to remotely activate the clamp to a non-interceptive position. With approach of joint 38 to clamp 77 certain advance preparations minimizes the time to add a pipe segment 46a to lengthen constituent 46 while penetrating the strata as a continuing operation.

This anticipation principally includes transfer of a pipe segment 46a from the stock of pipe aboard the service station 20b to an erect posture immediate to its installed position as suspended by a hoist 83 fixed uppermost on the control station. A valve 85 is shut off just prior to disconnecting the joint 38; so that during the seconds time required to effect the lengthening, the inertia effect of the moving fluid column is depended upon to maintain the jet at the hole bottom. Frame 41 bearing freed joint 38 is raised by hauling-in on crane 39 and paying-out on reel 118b to provide space above the clamped coupling to add segment 46a. With the conduit 46 lengthened crane 39 is reinstated to respond in lowering the conduit 46 and the clamp deactivated to normal position for interception of the next coupling.

The drilling station a, as can be best seen from FIG. 2, comprises a stationary portion 154a and a portable portion 156a. These portions couple together to fonn the composite structure seen in FIG. 1. Three individually operable telescopic legs 182 are mechanically powered through gearing associated with the turntable 202 to establish an erect posture of the drilling station as monitored by leveling device 248. The leveler 248 also serves as a constant sentinel to the erect posture of the drilling station to re-establish firm footing if affected; so as not to bend the drill string.

The portable portion 156a as can be best seen from FIG. 4, comprises a framework 166a of generally hyperbolical shape terminating in a journal 168 at or near its top 621. The journal rotatably supports a torque tube 170 extending longitudinally of the framework 166a. The lower end of the torque tube 170 is rotatably received in journal 172. Pontoon 620 is the base to which the framework 166a is constructed, thus the pontoon is part of the portable portion 156a to enable various controls for it to be periodically inspected.

' -Pontoon 620 is sectionalized to provide a separately controlled gas chamber for each of the three adjustable legs. The chamber is penetrated by a cylindrical member 175 to define an upper connection with shell 158 to provide an axial guide for bearing member 174 transmitting radial load of bearing 172 to the portable portion 156a. Cylinder 175 provides clearance for the mounting of the top section 354 of the diverter to hearing member 174. Torque imparted to the torque tube 170 through means of the rotary table 202 fixed thereto is transmitted to the drill string 146. The couplings 148 are spaced apart by a distance less than the length of the torque tube 170. Thus, at least one coupling is at all times driven by the torque tube.

(In FIG. 11) The diverter assembly 348 is connected between the surface well casing 350 cemented to the floor 152 and the bearing member 174 supported from removable portable portion 156a of the drilling station 150a. Assembly 348 is separable to permit; removal of the portable portion and drill string for reassemblage as needed, and to divest the well of the string to permit e.g., lining the bored hole with casing. Thus bottom section 352 with the stationary portion of the drilling station remains fixed to the well comprising the diverter portion 347 and conventional blow-out preventer 353 adaptable to seal off the well with the string in place or removed. The top section 354 is automatically fastened to and remotely disengaged from and re mountable the bottom section by jaw assembly 356 locking conically faced flanges 349. A pump 355 and valve 351 are optionally included in the remote conduit assembly. (See FIG. 2) Controls (not shown) to bottom section 352 of diverter assembly 348 are trained along the remote conduit 362 and stationary portion 154a so remain with the permanent portion of the installation.

(In FIG. 10, 11) The diverter assembly accommodates sealed entry of the bared string, with the diverter portion 347 directing flow from the well annulus 53 via branch outlet 358 and formed conduit 360 to the remote conduit and has terminating mechanism 357 sealing off the annulus with a mitigated well condition at the seal.

The purpose of the terminating mechanism 357 is to establish a fluid tight seal between the partition cap 372 and the drill string 14 6 and pass the coupling 148 into the assembly. The purpose of the throttle assembly 363 is to mitigate detrimental characteristics of the well fluid to the extent that an environment is established in the transition chambers 359 a, b most conducive for passage of the coupling and also thereafter prolong the effective seal.

In the operative position the throttle assembly 363 defines the floor of the transition chamber and provides a lengthened sleeve 367 shrouding a length of the tubing of the drill string with close annulus clearance 369. Thus the tubing is free to pass through the transition chamber floor with restricted leakage fluid flow into the transition chamber. The close fit of the sleeve to the string rejects entrainment of particles dimensionally in excess of the clearance measurement and the extended length of the sleeve effectively increases pressure drop between inlet and exit of the leakage fluid to such an extent that pressure in the transition chamber is markedly less than in the well. For the condition when well pressure is greater than surrounding water pressure then the mitigated conditions within the transition chamber correspondingly diminishes the pressure differential across seal 357. Well fluid confined in the diverter assembly below throttle assembly 363 is virtually stagnant by reason of the restricted leakage; so that solids in suspension settle out providing a classified slurry in chamber 361 seeking entry to the clearance annulus 369. Throttle assembly 363 and seal 357 as operative members are separable means to provide passage through of the coupling 148 with monitoring and control means automatically attending these operative members.

Halves 419 bearing against internal ring flange 372 opposes higher pressure of the chamber below it and backs up the seal 406 in contact with string 146. To make this seal more effective gland halves 696 are free to be urged against seal 406 by the mentioned pressure and retained in assembly with the parted halves of members 419 by dovetails 697. All of the power units are represented as 421 and are serially actuated by a cam disc and switch means associated with selsyn 61 to pass couplings. (In FIG. 6) Universal fitting 50b comprises: a tubular housing 68a fastened to cylindrical member 138b in turn fastened to shell 70 of the station 52b; a first tubular element 72 coupled to the lower end of conduit 46 by a weighted coupling 74a, and extending downwardly therefrom slidably into the housing 68a for rectilinear movement relative thereto; and a second tubular conduit element 76 received within the housing 68a and around conduit element 72 for rotational movement relative thereto. The housing 68a has guide means 78a fixed to and extending upwardly therefrom for guiding engagement with coupling 74a. The lower end of the conduit element 76 joined to the string by coupling 148 has a spherically shaped thrust collar 94 fixed thereto for rotation therewith. This collar is supported on a thrust surface 96 fixed to flange 516 formed to tubular support 138b elongated to accommodate mounting of tension equalizer 1416b. A built-in blow-out preventer 700 is formed in housing 68a to provide a sealing assembly of the well when the conduit 46 has been raised; so that then tubular element 72 clears and permits automatic closure of the preventer. Coupling 74a is depicted to be of considerable mass weighting down the lower terminal of the conduit 46.

The interior of cylindrical member 138a is also utilized to mount a retractable clamp mechanism 77a provided to engage with a coupling 148 in support of the drill string when the universal fitting 50b has been removed during retraction and dismantling of the string as to be subsequently discussed. (In FIG. 10) The lowermost position of the support station 52b/3is shown situated just above the top 621 of the drilling station. Since the array must now be altered after having reached the full extent of drilling depth of the integrated assembly, a float 712 is introduced below contol station 34a and assumes support of conduit 46. Thus by virtue of the slip connection at the universal fitting 50b the length of conduit 46 is removable as a unit for disposal and eventual dismantling as for instance at the forward end of vessel 20b utilizing derrick 26b. Instantly the lower terminal of the conduit 46 is raised above a limiting position within the universal fitting 50b, blow-out preventer 700 therein seals off the remaining string communicating with the well.

Thereafter the support station 52b is free to be raised to again occupy its initial position whereby that exposed string portion now extending below to the drilling station has been expeditiously withdrawn, permitted by the effectiveness of system 274 to manipulate the diverter sealing means 354. The result thus far has been to quickly remove an amount of the array corresponding approximately with twice the setting depth of water.

(See FIGS. 1, Thereafter the string is segmentally dismantled utilizing the clamp means 77 of FIG. 5 provided at position 75 on the bridge 79 of the control station. A plug assembly 711 is in readiness to seal off the exposed string end to serve as a blow-out preventer at the open end coupling supported by clamp 77. The vertically movable support station 52b fitted with clamp means 77a is essentially like and used alternately with the clamp 77 of the control station 34a to support the string. By repeatedly becoming engaged with a lower coupling, the support station is used to raise the string each time after a segment 146a has been removed from the array and stowed aboard vessel b to introduce the next segment within station 34a for dismantling. (In FIG. 8) after a sufficient number of string segments have been removed, as above, to expose the drill bit 284 above the base portion portion 154a, the remaining buoyant assembly may be disposed to a remote area; so that again a portion of the array measuring approximately the water depth is removed for eventual dismantling. Now then the well may be cased as covered in Ref. B, sooner than if all segments had been individually detached from the array.

Summary of incidences during dismantling of the array pertaining to the effectiveness of the system employed is as follows: A unit removal of the extended conduit 34 between the control station and the support station during which short time blow-out preventer 700 seals of the well still subject to injected pressurized drilling fluid; rapid withdrawal from the well of a portion of the drill string commensurate with the increased well depth of the drilling stage when completed and still sealed by preventer 700 with increased rate of fluid injection to occupy the vacated space as it occurs; coupling design and mode of handling to effect dismantling a length of string commensurate with the portion remaining below the diverter assembly still sealed against blow-out incidents (plug assembly 711) except during each interval when the support station segmentally raises the string with continued fluid injection as mentioned; final unit removal of the remaining exposed string freed from the diverter fixed portion left to dominate the well by preventer 353 and valve 351 regulating remote conduit 362.

(In FIG. 4) This view of the drilling station (incidentally only of the portable portion 156a) provides a diagram to illustrate the coincidence in position of the sheave 272 of the accommodation system 274 employed to manipulate the sealing means of the diverter top section 354; so that couplings 148 are passable therethrough. It is recalled that reel 118a is periodically used in connection with sheave 272 to account for the store of wire portion 99a accumulated commensurate with the segmental movement of the string (amounting to the distance between couplings). Thus in the case when retracting the string, the sheave is disposed to a lowermost position D when a coupling 148 is imminently below lowermost first throttle 363a. With raising of the string by the support station 52b, the wire portion 99a is raised moving sheave 272 upwards thus activating selsyn 61 to monitor power units 421 to open throttle 363a while coupling 148 passes by. Thereafter throttle 363a is closed defined as a restored position and succeeding secondary throttles to include final seal of terminating mechanism 357 are serially manipulated until the coupling and sheave each are at position C." Thereafter that coupling is free to travel upwards, while the selsyn 61 continues to turn but ineffective with the monitor system until the next lower coupling assumes position D. Coupling spacing A to B equals the torque tube length. coupling travel D to E is twice that of sheave travel D to E, as is the relationship when the coupling traverses the diverter portion 354. As in Ref. D" stops 662a, b, act on switches 664, 665 selectively altered depending upon operational function of drilling or retracting the array.

(In FIG. 1a) Service station 20b is equipped with means to disengage assembly 22 and displace it temporarily during assembly periods (if desired) so as to provide access to alley way 10 and head room directly above. Such a condition is illustrated with the introduction of a monorail 11 in this cleared area to accommodate an electric powered cable hoist 12. An accessory for hoist 12 in addition to the terminal hook is a conventional pipe tong which is self locking when loaded and self opening when unloaded. Extending above vessel 20b is a tower to support a hoist 26a having accessories principally including wire or chain slings which can be quickly adapted to engage with or disengage from a pipe.

Servicing of assemblies 46, 146 is disclosed in the following with reference to previous comments regarding lengths of conduit sections and their storage. Pipe storage areas extend substantially the length of and on both sides of alley-way 10 that in effect contrives vessel 20b to a catamaran. Sections 46a, 146a conveniently occupy the length of these areas, and are anticipated to exceed 150 lengths, representing the assembly increment of change to the array. Phantom illustration depicts the method to add a section to the array with tongs and slings supporting the section drawn somewhat outboard of the storage area. Thus the alley-way has been utilized as a clearance space for the movement of elongaged sections. Slack off of hoist 12 will stablish the section to a vertical position whereupon the lower tongs are disengaged. The lower end of sections are guided through passage 45 assisted at entry by flares, and at the upper end encased so as to confine a section within structure 36.

In this position sections 46a for instance will be oscillating vertically responding with movement of hull 20b, whereas station 34a is essentially immobile. A sling off hoist 83 engages section 46a, 146a approximately where previously supported by the tongs. With an upward surge of a section, as mentioned, hoist 83 is activated to take over the support of a section; so that with descent of hull 20b hoist 26a is made ineffective. Having accomplished transfer of a section to a stable hoist the newly assumed length is positiond to be made up between a coupling connection supported by clamp 77 and the flexible joint 38 as again connected to the returned assembly 22.

The review thus far provides a background disclosing apparatus and method associated with the proposed means to satisfy the purposes of this application. (In FIG. 8) The close coupling three stations 34a, 52b, 150a are towed to a site as united either separated from or with the vessel b. Pontoons 40 are depended upon for principal buoyant support, whereas buoyant support from chambers in pontoon 70 and 620 are minimized. As depicted the unit arrangement may be in a selected stage of assembly depending upon circumstances. The monitoring and control system regulating buoyant support for normal operation is relied on to retain a selected freeboard of superstructure 36 during transfer of apparatus between sites.

A shaft alley 735 extends through this central vertical axis to provide access for addition or removal of replaceable members needing service. As example, FIG. 9 shows a portion of structure 166a so constructed as to be separable when the string drill bit and diverted assembly must be removed. Rabbett fits 736 accommodates such separation together with splines 737 where torsional stresses must be transmitted.

The facility by which the stations are unified and rearranged in assembly together with the ready adaptability of the drilling station to floor contours makes this apparatus most suitable to undertake drilling vertical wells in a field of preconceived spacing without the need to slant drill from a common fixed structure. In this regard the bottom section 352 and stationary portion 154a are left as permanent portions at a completed well as a means to re-enter the hole to recondition it as needed following a certain lapse in time or because of decreased productivity. Thus for each new site a new base portion 352 is added to the assembly of FIG. 8 by lowering one already secured by 3 pendants to pontoons 40 to hang below, and station 156a to be then lowered for engagement therewith by automatic clamp means 164. (In FIG. 10, 11) The discussion covering the diverter means dwelled on terminating well annulus and to accommodate sealed passage of the string through a series of adjacent chambers. The leakage of well fluid across first throttle 363a from stagnant chamber 361 to first transition transition 359a is evacuated through port 738 by a lift pump 739 via secondary conduit 740 to a remote sump 702 aboard the surfaced vessel 20b. The rate of leakage flow through the annulus 369 is minimized by decreasing that clearance area, by increasing the length of the throttle resulting in increased pressure loss across the throttle ends.

The resulting decreased pressure if sustained within first transition chamber 359a adversely affects the discharge capacity of the lift pump 739 operating against high hydrostatic pressure. This effect is averted within chamber 359a while drilling by utilizing the piston effect of close fitting couplings 148 to the inner walls of torque tube 170 to displace entrained water into the uppermost chamber 359s of member 376, whereupon that water is bypassed terminating mechanism 357 into intermediate chamber via second sump system 3715b. From chamber 35% this water is discharged to chamber 359a having bypassed secondary throttle 363b via first sump system 373a. A relief valve 742 (solenoid operated) provides for the restricted escape of water so as not to be entrained with fluid up conduit 740 yet maintains the pressurized water system established by coupling 148 with translation through tube 170.

The coupling descent in the torque tube acts as a displacement pump with restricted discharge through valve 742 thus establishes a suction pressure for the pump and an opposing pressure to minimize leakage through throttles. The pump 739 arbitrarily chosen for illustrative purposes operates on the air lift theory, utilizing the supply of nitrogen gas available at the drilling station as the media by which the density of the discharge column is lightened.

While throttle 363a is parted to pass a coupling, then secondary throttle 363b checks leakage into chamber 35% whereupon such leakage is pumped back to chamber 3590 via sump system 373a as acted on by said water supply. Meanwhile the capacity of pump 739 is increased with increased gas charge.

When retracting the string, the piston action of a coupling is reversed requiring a vacuum breaker 743 to admit water into chamber 35%; also the pump 739 is relied on again to have increased discharge capacity. It should be noted, however, that the string is rapidly withdrawn so that the throttles are only instantaneously opened contrary to the prolonged opening in contention with progress in penetrating the strata. Furthermore, with the omission of the lengthened conductor pipe in reach to water surface, the frequency of occurrence of throttle opening to pass couplings when subject to well conditions is greatly diminished, depending upon the assemblies removal as a unit from the well as previously stated.

Having completed the boring of a well with the smallest bit, the array is retracted so that the string assembly may be rearranged to include a larger bit in a preparation to drill a new hole at another site. Both such adjustment and maneuvering is affected through the unit compaction of the three stations as stated. Also it is recited that this rearrangement is performed with the array remotely disposed from the bored well by turning the vessel 20b end around to present a previously prepared casing assembly for entrance to and cementing in the final lining of the hole.

(In FIG. 3) This figure may be also interpreted to represent the first situation at a new site when the drilling station 150a has finally seated to the floor having been supported in part off the floor by the weight needed to press in the surface casing into the hole bored by the drill string. In this case flushing water was furnished by pump 80, associated with universal fitting 50b in FIG. 7 to entrain cuttings as a slurry for discharge via conduit 362.

(In FIG. 12) The diverter system 348a is utilized to terminate the annulus of a conventional drilling rig employing a kelly bar as the transmission means to torque the drill string (omitting the torque tube). This applies for land based drill rigs, platform mounted rigs over water or for drilling rigs with towers fashioned to the back of a buoyant vessel. In order to minimize the height of towers-the diverter is shown located in a bored pit 744 for the land rig and said pit may be construed to be a caisson if desirable for over water rigs. The distinguishable difference is the substitution of the kelly bar 745 for the torque tube and the location of the diverter assembly 348a near the water surface as an extension of the conductor pipe 350a in reach through the body of water versus the immersed station 150a and diverter assembly 348.

To accomplish this difference the member (now) 376a is lengthened so that space is provided accommodating the special coupling l48b joining the polygonal sectioned kelly bar to the tubular drill string in travel between the turn table 202a and terminating mechanism 357. An elongated vertical cylinder 747 surrounding coupling l48b with close annulus clearance is fixed to the table 1741; to replace torque tube 170 as the means to entrain water for pressurizing chamber 359C as previously related.

In the case without a cylinder 747 no piston pump action occurs so that chamber 359a is not charged with pressurized water but rather pressure is diminished therein with respect well pressure by action of throttle 363a. Nor is there need of such pressurized water with the diverter at the water surface where pump 739a adequately evacuates leakage against relatively low hydrostatic head to pit 746 via conduit 740a. Sump system 373a, 373b evacuates leakage from chambers 35% and 35 90 by said pressurized water when throttle 363b has been the fluid check against leakage while throttle 363a was opened to pass coupling 148. (In FIG. 14) This arrangement differs from the preferred arrangement (with the drilling station positioned as an immersed apparatus at the floor) in that the diverter is hereby connected to an extended conductor 350 with the drilling station located at the surface, supported by an elevated platform or on a buoyant vessel. This may be accomplished in a variety of ways with the turn table 202b relocated at the top of the torque tube below water level 28a or above water level 28a, then adapted to receive a supply of water through port 748 to be intercepted for displacement within chamber 3590 by coupling 148.

A conventional draw works and swivel as in FIG. 15 supports the drill string with fluid flow therethrough to the drill string.

(In FIG. 15) This arrangement provides for the turn table and diverter to be connected to an extended conductor 350 but encapsulated in a housing 749 disposed below water surface free from turbulent conditions. Buoyant of housing 749 maintains the conductor in tension while stays 750 retain the plumb of the array. The drill string 146 is vertically movable supported by the draw works 751 suspended from derrick 752 upon a platform or a vessel 753. Drilling fluid is supplied through swivel 754 connected to string tubing with clamp 755 used to hold the string when adding a segment. Since the kelly is not used the raising of the string to replace it with a tubing section is avoided. The torque tube 170 is shown projecting through a sealing means 756 of the capsule 749 so the couplings 148 again may perform as liquid displacing pistons. The capsule is shown to have a hatch-way 757 in communication with the work area above, noting there is no more manual attention during operation than for the deeply submerged arrangement.

(In FIG. 13) This arrangement of the diverter assembly shows the chamber 361 elongated sufficiently to include the drill bit 284 and drill weights 758 above an additional 8.0!. 353a, so that when the diverter assembly is parted at flange 349 all the entrained drilling mud contained in string 146 and ejected from bit 284 can be saved for pump 739 to recover.

(In FIG. 10) This partial view of the diverter assembly shows another variation in assembly whereby the branch outlet 358a is now a port from chamber 361; so that the lower fixed portion heretofore known as 352 includes any other preferred well head equipment to control the well.

(In FIG. 4) The accommodation system 274 relating hole penetration to the crane 39 is herewith interpreted to be a selsyn transmitter 61 clutched to a sprocket 63 engaging a chain 65 connected at one end to the guide bearing of one of the sheaves 272 and the other end weighted 67; so that when the transmitter is rotated with descent of the sheave it electrically activates a selsyn receiver 49 monitoring the motor powering crane 39 to provide movement of conduit 46 corresponding to movement of string 146. The clutch 69 becomes disengaged in opposite rotation of sprocket 63; so that crane 39 doesnt respond when re-establishing the upper position of sheave 272.

FIG. 15 is typical of arrangements employing draw works 751 as the sole means to manipulate the drill string attached directly to it. Therefore the omission of the articulative conduit comprised of members 46, 38 and 22 makes other members such as crane 39, support station 52b, wire system 99a, b and their appurtenances needless.

However, a part of system 274 is adapted to retain monitoring and control of diverter assembly 348. As in FIG. 4 sheave 272 is supplanted by a wire or other suitable means for connection to the tail block of draw works 751 with the selsyn mechanism and associated appurtenance disposed thereabove. Thus as the draw works is manipulated to alter the string position, the diverter mechanism is actuated to suit each coupling being transmitted therethrough.

In FIG. 7 a typical arrangement employing structure 500 is disclosed herewith to apply as well for the monitoring and control means of other buoyant chambers of pontoon 620 and 40. Variable buoyant support provided is dependent upon gas chamber volume adjusted by differences in liquid surface level supporting a float which actuates magnetic switches at limiting level position established by a motor remotely controlled. A buffer liquid 482 is typical of the means to retain gas purity within the chambers to save mechanisms contained therein from deteriorating effects of the sea water restricted below in transition through foot valve 480.

(In FIGS. 4 and 6) A pair of magnetic switches 181, 183 mounted to an extension 185 of fitting 50b are spaced so that a vane 189 mounted on coupling 74a becomes engaged with one switch depending upon position to activate a monitor regulating crane motor speed to correct the end of conduit 72 to neutral position in fitting 50b. Any sudden freeing of the bit when retracting the string from the well causing the support station 52b to rise more quickly than the conduit 46 can be raised is monitored by a magnetic switch 187 which when engaged is done so by the vane 189 at an excessively lowered position. Switch 187 is electrically wired to activate a solenoid opened blow-ofi valve venting the gas chamber of support station 5212 to instantly avoid compressive liability to conduit 46 designed only as a tension member. Such relief is also a warning to avoid further supercharging of the buoyant chamber when extracting the bit.

(In FIG. 7) Equalizers 106a and 10612 are inverse assemblies of one to the other. The two beams 108 and 110 are pivotally mounted to housing 138a by axis 191 and 193, respectively, extending normal to and at the longitudinal centerline of housing 138a and oriented to provide the extension of the wires 100, 102 and (104 are shown) upward past and clear of preventer 700 and pump 00. A third beam 112 is fastened from the distal ends of the first two beams by intermediate cables 114 and 116. The lines 100 and 102 are secured respectively to the close ends of beams 108 and 110 and the line 104 is secured to the center of beam 112. The pivot axis of the beams 108 and 110 are spaced from the distal and close ends in a two to one ratio thereby geometrically equalizing tension in the three lines.

(in FIG. 7) Three rods 298 fixed to and depending downwardly from support station 52b in oriented alignment with wires 100, 102, 104 terminate with an axis 317 serving as the fulcrum of a lever 319 pivoted about axis 317. A ring 310 supported by wires 100, 102, 104 at a level with the extension of the lever short arm 321 is connected to arm 321 by radially extended links 323. The lever long arm 325 terminating with a vane 304 has an erect posture 325 and a displaced position there to activate a magnetic switch 316 fixed to support station 52b. Thus the displacement of support station 52b occurring with slant of wires 100, 102, 104 displaces the lever 319 with corresponding end movement proportional to the lever arm ratio; so that the monitoring means is more responsive to movement of the array. Aside from the observation that lever 319 is counterweighted to be self balancing, the mechanism 296 functions as disclosed hereafter.

The motion imparting portion of the alignment mechanism 296 comprises: awater manifold 326 (see FIG. '7) of annular configuration fixedly supported on the station 52b in concentric alignment therewith; a centrifugal pump 328 interposed in the manifold 326 to effect the pressurization thereof, said pump being driven by motor 324; a plurality of radially extending nozzles 330, one of which is secured in fluid communication with the manifold 326 in radial alignment with each of the rods 290; an electrically operated valve for each of the nozzles 330 normally maintain it in a closed condition and, upon energization, effect its opening; a pair of electrical leads connecting each of the valves across the switch 316 associated with the rod 298 radially aligned with the nozzle thereof.

Through the foregoing arrangement, when the station 52b traverses laterally relative to the station 150a, the radially extending nozzles 330 are selectively activated to return the station to a vertically aligned condition. It should be appreciated that more than one of the nozzles might be simultaneously activated, depending upon the direction in which the station 521) moves out of vertical alignment with the station 150a. It is movement of the ring 310 relative to the station 52 which effects selective operation of the nozzles.

The control station 34a is maintained in vertical androtational alignment with the support station 52b through means of an alignment mechanism corresponding substantially to the mechanism 296, with the following exceptions:

1. the rods of the mechanism (those corresponding to the rods 298 are fixed to and depend from a structure 36;

2. the rod (i.e., that corresponding to the ring 310) is monitored by the three guy lines; and,

3. the vane switches function to control operation of at least 4 sets of jets 30 and 32, rather than a manifold and nozzle arrangement. See FIG. 1.

The mechanism includes no structure corresponding to the manifold 326 and the nozzle 330. It, rather, functions to control the propelling function of the jets 30 and 32. This, in turn, controls the position of the station 34a, since a guide with passageway 45 maintains the stations 20b and 34a in spaced and rotational alignment.

(In FIG. 5) The plug assembly 711 is dependent upon a rail 723 fixed to structure 36 permitting displacement of assembly 711 to and from axial alignment with the string 146 supported by clamp 77. When a coupling releaser (Ref. B) is used it may be mounted to and integral with plug assembly 711; so that both straddle the string when out of use and selectively aligned when needed over the string by linkage 724 (power activated) connecting the assembly to structure 36. Assembly 711 comprises a movable carriage 725 providing the journal for plug 726 that is brought to bear with coupling collar 542 by an axially movable screw 727 actuated by a nut 728 held in fixed position for rotation thereabout by its peripheral gear 729 in mesh with pinion 730 mounted on rotary power means 731 likewise supported by carriage 725. Thus in event of a blow-out (release of formation fluids), the plug assembly is moved from a stored position by linkage 724 to alignment over the string coupling; whereupon the motive power 731 is automatically actuated to power plug 726 into fit with fixed coupling collar 542; so that gasket means 551a seals off the well, supplementing the coupling gasket 551.

(In FIG. 5) The coupling 148 is temporarily secured to super-structure 34a by arranging the back of the coupling shaped to a frustum of a cone to bear upon a clamp mechanism 77 mounted to a bridge 79 spanning the base 43 to permit changes be made as needed.

Bridge 79 provides rigid support of a peripheral bracket formed with a series of stops and drilled lugs bearing pins 111 about which intercepters 113 pivot from a radial inward position 115 to an erect postion. At least 3 intercepters are uniformly spaced from the peripheral bracket so that when in position 115 they will support the couplings 148 at the cone face. From position 115 the intercepters can only turn upwards because of interference by the bracket 105. Accordingly, the intercepter does not interfere but is tripped out of place when a coupling is raised past the clamp. In order to pass a coupling down past the clamp however, the intercepter is rotated upwards by activating a solenoid 123 which then pulls on a rack 125 in engagement with gear teeth 127 formed concentric with pin 111 in the hub of the intercepter. See FIG. 1. Remote conduit 362 is fastened to drilling station a by compensating coupling 643 and is thereafter buoyantly supported by a pontoon system 366 for extension by a fixable arrangement 710 in accommodation with its connection to conduit 706 aboard heaving surface station 20b to provide discharge of slurry composed of the drilling fluid entraining formation cuttings to sump 702 through one leg of Y fitting 704 for processing as required drilling fluid thereafter transferred to supply sump 710. Conduit 706 is connected at one end to the other leg of Y fitting 704 and connected at the other end to one leg of another Y fitting 708 providing a connection at the other leg of Y fitting 708 to which pivotal constituent 22 is connected.

Valves 85, 707 and 705 included in the fluid transmission system are selectively manipulated so as to provide alternate circuits. For normal drilling the flow of fluid initiates at supply 701 for flow via conduits compressed sequentially of members or passages 22, open valve 85, 46, 146, jets from 284, then returns via annulus 53, diverter portion 347, branch outlet 358 and extension 360 thereof to coupling 643, 362, 710, 704, open valve 705 to sump 702 with valve 707 closed. When retracting the drill string the circuit initiates with fluid flow at supply 701 with valves 85 and 705 closed and valve 707 open, reversing flow of the normal flow circuit to maintain annulus 53 full of pressurized fluid as the string is vacating the well and or thereafter with blow out preventer 353 closed.

CONCLUSION From the foregoing description it is believed apparent that the present invention enables the accomplishment of the object initially set forth herein. It is understood, however, that the invention is not intended to be limited to the specific details of the exemplary embodiment herein described. No attempt is herein made to enumerate all possible variations or include various incidental elements.

What is claimed is:

1. In an apparatus having, an extended drill string with a lower end weighted to impress a drill bit powered by a rotary turntable selectively disposed in elevation above a site for penetration of strata remotely below to bore a hole in forming a well, a fluid transmission system in part conveys drilling fluid from a fluid supply through a cored hole in the drill string for ejection from the drill bit at the hole bottom to entrain formation cuttings as a slurry up the annulus around the drill string formed with the hole progressively lined by casing with a conductor above fastened to said casing to extend the annulus to provide a protected environment from material conveyed therein, a vertically movable support means from which the string suspends regulates bit pressure upon said bottom, a wire system transmits said support means vertical movement to sense an accommodation system employed to monitor and control power means incorporated in a diverter assembly by correlating a coupling sequentially imminent to a partable fluid seal terminating mechanism and at [eat one well pressure ameliorating throttle assembly therein as operative members by said power means to provide passage of the drill string there-through with a normal close clearance when in a closed position around a string segment or in an expanded open position to permit passage of diametrically larger couplings than said segments connected to effect the extended drill string, the improvement comprising:

a. said diverter assembly embodying a branch outlet and a remote conduit, wherein:

l. a sump provides for storage of slurry transmitted by said remote conduit included in the fluid transmission system having extension by a fixable arrangement providing a selective alternate circuit with said fluid supply;

2. said remote conduit supplants said cored hole to introduce drilling fluid to fill the void formed in removing the drill string from the conductor and hole;

3. an evacuating system provides for the transmission of leakage of well fluid past a lowermost first throttle assembly to said sump;

b. an elongated vertical cylinder surmounts the diverter assembly to provide fluid sealed transmission of water therebetween from a remote source with passage of said couplings as pistons through said cylinder to establish a pressurized water system in support of both the operation of the diverter assembly responding to said accommodation system selectively providing passage of the drill string therethrough, and containment of said slurry for dispersement through said branch outlet and said evacuating system, with said throttle assemblies and terminating mechanism incorporated together as the operative members terminating said annulus; and,

c. the diverter assembly having a bottom section to include a blow-out preventer disposed to selectively dominate the well above said branch outlet remains fixed to the conductor, and a remountable top section accommodating rearrangement of the drill string encompasses a series of adjacent chambers having floors formed with partitions spaced to accommodate a coupling therebetween, said sections removably secured together by a jaw assembly automatically fastening and remotely selectively disengaging sections.

2. In an apparatus according to claim 1, wherein said chambers include, an upper chamber having a floor formed by a partition in support of said terminating mechanism, at least one intermediate transition chamber therebelow each having floors formed by a partition in support of secondary throttle assemblies, a first transition chamber therebelow having a floor formed by a partition in support of a first throttle assembly, a stagnant chamber, therebelow having said jaw assembly, the apparatus further comprises:

a. bypass systems to provide transmission of water from said cylinder in communication with said upper chamber to circumvent said terminating mechanism and secondary throttle assemblies for restricted discharge from the first transition chamher.

3. In an apparatus to claim 2 having a supply of water available, wherein the improvement further comprises a vacuum breaker fixed to the upper chamber in fluid communication with said fluid supply provides unrestricted flow of water to the diverter assembly with ascent of the drill string therethrough for entrainment of water in said cylinder by the couplings in reverse passage with retraction of the drill string.

4. In an apparatus according to claim 3, the improvement further comprises: a torque tube formed by fixing the elongagted vertical cylinder to turn with the rotary turntable including a torque transmission means between said cylinder and at least one coupling always in translation therethrough, and adaption of said fluid seal transmission arrangement to accommodate the rotation of the cylinder respective the upper chamber.

S. In an apparatus according to claim 4, the improvement further comprises:

a. a drilling station incorporating said rotary turntable established to the floor of a body of water as an immersed object connected to the diverter assembly terminating a shortened conductor;

b. a buoyant support station provides said support of the drill string with descent as a unit commensurate with said penetration;

c. an articulative conduit transmits drilling fluid to said drill string from said fluid supply; and,

d. a control station having buoyant supports immersed below the surface of said body of water provides a stable and regulated support of the articulative conduit in response to said accommodating system.

6. In an apparatus according to claim 4, the improvement further comprises:

a. a lengthened conductor accommodates establishing said turntable above the surface of the body of water with the torque tube and diverter assembly immersed; and,

b. a conventional draw works and swivel provides support for the drill string and fluid flow therewith.

7. In an apparatus according to claim 4, the improvement further comprises:

a. a buoyant housing immersed below the surface of a body of water maintains tension in the conductor including stays establishing vertical posture of the array contained within the housing comprised of the diverter assembly and turntable with torque tube extended in fluid sealed arrangement therethrough in fluid communication with said body of water; and,

b. a deck and derrick therewith disposed above water provides for the stable support of a draw works and swivel comprising the support of the rotating drill string and transmission of drilling fluid from the supply to said cored hole.

8. In an apparatus according to claim 3, the improvement further comprises:

a. a drilling station incorporating said rotary turn table and diverter assembly terminating said conductor;

b. a conventional kelly bar in transition through the rotary turntable transmits said power to the drill string; and,

c. a conventional draw works and swivel provides support for the drill string and fluid flow therewith.

9. In an apparatus according to claim 8, the improvement further comprises:

a. a bored pit accommodates the disposition of the diverter assembly below the drilling station;

b. lengthened said supper chamber provides space to accommodate said lengthened cylinder extending to the drilling station;

0. a special coupling joining the kelly bar to the drill string adapted with close clearance respective the bore of the cylinder serves together as the displace ment pump for the pressurized water system with repeated descent following each extension of the drill string by a string segment; and,

d. monitoring and control means manipulated by said draw works activates the accommodation system providing passage of the drill string through the diverter assembly.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4883388 *Apr 8, 1987Nov 28, 1989Cherbonnier T DaveLoad compensating system
US4886397 *Aug 27, 1987Dec 12, 1989Cherbonnier T DaveDynamic load compensating system
US5269629 *Jul 29, 1991Dec 14, 1993Shell Oil CompanyElastomeric swivel support assembly for catenary riser
US5673804 *Dec 20, 1996Oct 7, 1997Pri Automation, Inc.Hoist system having triangular tension members
US6360822Jul 7, 2000Mar 26, 2002Abb Vetco Gray, Inc.Casing annulus monitoring apparatus and method
US9816323 *Nov 24, 2015Nov 14, 2017Enhanced Drilling AsSystems and methods for subsea drilling
EP0218405A2 *Sep 22, 1986Apr 15, 1987T. Dave CherbonnierDynamic load compensating apparatus
EP0218405A3 *Sep 22, 1986Mar 9, 1988T. Dave CherbonnierDynamic load compensating apparatus
Classifications
U.S. Classification175/6, 166/358, 166/350, 166/352
International ClassificationE21B7/12, E21B7/124, E21B19/09, E21B19/00
Cooperative ClassificationE21B19/09, E21B7/124
European ClassificationE21B7/124, E21B19/09