CA1065624A - Off-shore oil field production equipment - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

Off-shore oil field production equipment with a production plat-form anchored on the ground of the drilling site, comprising a column pivotally connected through a universal cardan joint coupling to a base anchored to the sea bed in connection with a remote-located floating gas flare for burning gas extracted from the oil, wherein said gas flare is carried by a floating structure coming up into the wind while being connected to a swivel head of the column by means of a pivoted holder.

Description

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- The invention relates to off-shoxe oil field production equipment, outfit or like rigging comprising off-shore platforms or the like.
Its main object is the provision of a number of arrangements to be used together or separately with a view -to substantially cutting down the investment;coæts and making fields payable or workable with small outpu-ts or flow rate capacities.
It consists aocording to one of such arrangements to make use of a production of platform in particular of the kind anchored or fastened onto the ground of the sea bed or bottom of the drilling site and for instance pivotally connested to a base member, such platform comprising an oil and gas separator or like trap and being combined with a gas flare adapted to be located at a suitable distance from the center line of the platform, saia gas being carried by a floating support coming up into the wind or orienting itself in the eye of the wind while being connected through at least one articulated arm to a rotary element in particular a swivel or re-volving head of the platform.
Another arrangement consists in connecting by means of an oil pipe-line to a production platform in particular of the kind just referred to herein above, a oombined storage and lading platform assembly having in particular a base member anchored to the ground or the sea bed and forming a storage tank and at least one articulated column on this base member, which column is fitted with an equipment for loading oil tankers in p~r-tioular of the type described, in US patent N 3 980 037 ~-p~r~'~po-~ ~ in the name of the Applicant Company.
- ~ Said production column or tower may be associated with a number of wells distributed ab~t~b~e m~b~ or also said wells may be drilled from said base member, in combination with valve ana manifold systems en-abling the crude oil to be carried along or conveyed towards the separator, thence the oil released toward the storage and lading column or tower.
3 Apart from said arrangements the invention comprises some other con-trivances or appliances which are used preferably at the same time and which will be set forth the more explicitely hereinaf-ter.
~he invention is more particularly directed to some embodiments for applying as well as to some embodiments for carrying out said arrangements and it is more especially aiming in particular by way of new industrial produots, at equipment of the kind referred to apply said arrangements as well as at the special elements required for devising or making same and installations or plants comprising such an equipment.
~he invention will be better understood and further objects, details, 4 characterizing features and advantages thereof will appear more clearly as the following description proceeds with reference to the accompan~ing ~g~m-matic drawings giv~ byway ofnon-~miting examples only illustrating several :;

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specific presently preferred embodiment~ of the invention and wherein ;
- ~igure 1 is a perspective diagrammatic view showing an oil produc-tion plant or sy~tem de~igned aocording to the invention ;
- ~igures a and 3 separately ~how on a larger ~cale, the ~tructure supporting the ga~ flare and forming part of said sy~tem in accordance with the invention ;
- Figure 4 is a perspective view illustrating the base or bottom por-tion of a production column or tower of the type ~hown in ~igure 1 accor-ding to an alternative embodiment of the invention ;
- Figure 5 is a diagrammatic elevational view of a possible improved embodiment of the invention ;
- ~igure 6 i3 a similar view of another alternative embodiment accor-ding to the principle of the invention ;
- ~igure 7 i~ a view in a cross-3ection taken upon the line VII-VII
; of ~igure 6 ;
- ~igure 8 is a view similar to ~igure 6 but illu~trating the beha-viour of the system in the swell ; and - ~igure 9 i~ still another possible alternative embodiment of the system according to the invention.
According to the invention and more especially to that one of its applying embodiments as well as to tho~e of the embodiments of it~ various parts which seem to be referred construction at present, it is intended for instance to design or establish a plant or a ~ystem for the production, storage and lading of oil products from the wells of an off-~hore or sub-marine oil field and such a design should be carried out as follow~ or in a similar manner.
Such a system should comprise , - a number of wells which are to be drilled from a movable derrick platform or from a drilling ship or in any other fashion whatsoever such wells being provided with their usual accessories and fitting~ such a~
protection casings, safety or rel`ief valves, storm choke~ etc. 7 their up-per portion forming the well-head 3een at 1 in ~igure 1 ;
- a m.nifold device such a~ shown at 2 in combi.nation with ~et~ of .~ valves and piping~ enabling produc-tions of the well~ to be collected or gathered, whereas these valve~ may be accomodated or housed on the sea bed or on the production column or tower to be described hereinafter ;
- the production tower proper whioh according to the most advantageous embodiment con~ists of an articulated column 3, mount~d through a univer~al cardan coupling 4 onto a base member 5 with ballast tanks 6 and at lea~t one float:mea~s7 providing through the hydrostatic thrust for keeping a substan-! tially vertical position, such a column being moreover provided with an oil .

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and gas separator arrangement or trap 8 fed with crude oil through a duo-t 9 and from whioh the orude oil is flowing out in purified or ~orubbed oon-dition thr~ugh a duot 10 extending down -the oolumn for oonveying the sorub-bed or purified orude oil or oil towards the ~torage and lading equipment;
- a gas flare 11 adapted to burn the gas flowing from the separator and whioh preferably has the con~truc-tion described hereinafter;
- and the ~torage and lading equipment supplied by an oil pipe-line 12 followine or oontinuing the duct 10, whioh equipment consi~ts advanta-- geously, on one hand, of a base 13 anohored to the ground or sea bottom ~0 and forming a storage tank of any size and, on the other hand, of a lading platform carried advantageously out a~ an artioulated column or tower 14 pivotally conneoted through a universal cardan coupling at 21 to the base and provided with means for mooring ships 15, said column inoluding in par-tioular a swivel or revolving head 16 and a boom 17 adapted -to oarry the lading line 18 aocording to the arrangements of ~S patent ~ 3 980 037 in the name of the Applioant Company the whole assembly being of course com-bined with pumps 19 and valves 20 for drawing at will oil from the ba~e-tank 13 or for storing it thereinto.
Referring more particularly to the gas flare 11 it i~ carried out in 3uoh a manner aooording to one of the arrangements of the invention, tha-t it is located at sea at a substantial diotance from the produotion oolumn (for instanoe at100m to 200 m) while being oarried by a floating ~truoture adapted to come up into the wind or to orient itself in the eye of the wind, said ~truoture being oonneoted to a platform 80 as to be able to turn around the latter, and for this purpose the platform oompri~e~ a swi-vel or revolving head 22 to whioh i8 pivotally oonneoted~-a~ arm oonneoting that head to said struoture.
~he floating struoture 23 oarrying the gas flare 11 at one end thereof oon~ists advantageously of an assembly of generally ~quare, triangular or other oross ~eotional oontour, consisting of ~uitably trus~ed or braoed tubes, suoh a~ struoture being little sensitive to the eIIeots of the ~well. --~he ~truoture is oonneoted to the swivel head 22 by at least one arm 24 it-~elf built up from tubes and pivotally bearing with its end~, respeotively, on the one hand on the head 22 about a horizontal axi~ A-A and, on the other hand, on the struoture 23 about another horizontal axis 13~ igure 2).
The ~izes of the tubes of the ~truoture 23 are designed 80 that the water line is looated nearly half-way OI the height of the vertioal cro~s-~eotion as shown in ~igure 3.
Said tubes may possibly be used for oonveying ga~ but it seem~ prefe-rable on aooount o~~en~g g~8tou8e independent pipine~ suoh as 25 the end of whioh towards the oolumn is oonnected to the outlet pipe from the sepa-.

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rator by means of swivel or rotary joints diagrammatically shown at 26, 27.
Such a structure undergoes from the sea, even in a case ` of storm substantially lower stresses than a normal ship. It should be pointed out indeed that the oscillating motion of the articulated column woùld be braked by the movements of this stru-cture in the water and that it will result therefrom within the connecting arm 24 and its pivotal connections, efforts or strains will remain small whereas they could become very large if the gas flare 11 had the shape and weight of a ship of the same length (the expedient of using a support forming the hull of a ship being however not discarded).
In Figure 4 has been shown an alternative embodiment of the system wherein the well heads extend through the base 5 of the production column and are secured thereto in the case where ~-that base is of a large size (with for instance each side thereof `
measuring 50 m to 100 m).
In such a case, the base alone is installed first and the wells are drilled at the sites or locations provided for that purpose by means of a movable platform of known kind carrying a drilling equipment or derrick and using the engineering process of making directional wells in order to reach the full extent or bulk of the oil pool.
Once the wells have been completed and provided with their control members the articulated production column or tower is installed and the oil collecting pipe-lines are connected be~
tween the base and the column.
The advantage of such an alterrative embodiment is that it becomes possible by means of a simple and economical equipment carried by the column to accomplish on the well heads and inside thereof any maintenance works or operations that could prove necessary.

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In this connection the column may comprise all serv-icing means for controlling and possibly loading the well heads and/or their accessories (valves etc).
Irrespective of the form of embodiment chosen, it is possible, owing to the invention to carry out oil field produc-tion equipment the operation of which is enough understandable from the previous considerations so that any further description thereof may be dispensed with, said equipment exhibiting with respect to those of the type referred to already known or ex-isting many advantages among which:
- the advantage of concentrating to the greatest pos-sible extent the various essential parts on the platforms involved;
- the subsequent advantage of a cutting down the de-sign or installation costs even for deep water platforms (in-stalled at depths of 100 m to 200 m for instance); .

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- the ad~antage of allowing to easily store the production of several days when bad weather would prevent an oil tanker from carrying it away ;
the base member 13 of the production column or tower may exhibit a large ætorage capacity ;
- and the advan-tage of providing for a better super~ision or monitoring of the various parts of thewhole system.
Figures 5 to 9 in particular illustrate improvements made -to the gas flare æystem.
According to the alternative embodiments shown, an oil field produc-tion equipment with a gas flare associated with a sea-bed development or working structure and carried by a floating or buoyant support iæ characte-rized in that æaid floating or buoyant æuppor-t conæiætæ of at leaæt one æubmerged float stopped by an emerging holding mast bearing said gas flare.
Moreover, the flare feeding æupply pipe-line wh~h iæ relatively long æinoe æaid gas flare æhould be located rather far away from æ~d sea-bed d~e]opment ætructure iæ ætiffened or strengthened by a lattice beam or ~ like trussed girder or framework alongside of which it is secured in order to provide a substantially horizontal emerging arm pivotally connected to said working ætructure and held above water level by æaid holding maæt.
More æpecifically, ~igureæ 5 to 9 æhow one part of an oil field pro-duction equipment comprising in particular a æea-bed development or wor-king struoture 111 and as gaæ flare 112 coupled to the working ætructure 111 and kept above water level by a floating or buoyant æupport 113 ¢onsisting essentially acoording to the invention of a æubmerged float member 114 ætop-pea by an emerging holding maæt 115 bearing the gaæ flare 112. ~he gasflare 112 is separated from the remainder ofa syætem by a heat æhield 116~ ~urther-more the holding maæt 115 iæ conneoted to the æupply pipe-line 117 for the - gaæ flare 112 and the major por-tion of thiæ pip~ne ~tendæ sub~ antially hori-zontally and iæ pivotally connected (pivotal connection 118) to the working structure 111. More æpecifically the pipe-line 117 iæ æecured alongside of a beam or the like trusæed girder or framework 119 which stiffens or streng-thens same ; the combination of said beam wi-th said pipe-line formæ an ap-proximatively horizontal emerging arm 120 kept above water level by means of the buoyant æupport 113 and determining the spacing between the gas flare 112 and the working structure 111.
With -the expreææion "working struoture" is meant any production equip-ment unit, outfit or like rigging to which the gaæ flare may be connected.
~huæ according to ~igures 5 and 9 the structure 111 appears as being a platform æuch as a production platform whereas from ~igureæ 6 -to 8 it ap-pears that the working ætructure 111 may conæiæ-t of a production and/or se-parator column or tower, whereaæ the ætructure may be connected to the æea .. . . .. ,, ~, .

bed or bottom in etationary or pivoting relationship. In the caee of a production and/or separation column the emerging a~m 120 is pivotally con-nected to a revolving head 122 mounted in coaxial relation to the emerging top portion of the column. Said working structure could also consist of a ship such as for instance a tanker. ~he pipe-line 117 may oomprise several gas carrying duct sections 117a, 117b (Figure 7) secured alongside -the lattice beam 119 or being integral therewith. Moreover, said tattice beam 119 could be arranged (in a manner the showing of which is believed unne-cessary) suitable for serving as a service footbridge or like gang-way be-tween the working unit 111 and the gas flare 112. Now the various embodi-ments according to the invention, for providing connection between the gas flare 112 and the emerging arm 120 on the one hand and the buoyant support 113 on the other hand will be described.
As shown in particular in Figures 59 6 and 8 the holding mast 115 may be pivotally connected (pivotal connection 125) to the emerging arm 120. In suoh a case, it is necessary to provide a submerged arm 126 exten-ding in substantially parallel relation to the arm 120 and pivotally conneoted with both of its ends, respectively, to the working structure 111 (trough pivotal connection 127) and to said holding mast 115 (pivotal con-nection 128).~hus,the`submerged arm 126 f~rms a kind of parallel-mo-tion linkage or deformable parallelogram together with the emerging arm 120, the holding mast 115 and a portion of the working structure 111. The sub-merged arm 126 may however be omitted or dispensed with if the buoyant support 113 is provided with a ballasting mass 130 located below the float 114 (~igure 5). It is of course also possible to combine together a bal-lasting mass such as 130 and a submerged arm 126. In the case of Figures 6 to 8 where the working structure consists of a column the submerged arm 126 would be pivotally connected to a rotating ring 131 or like collar rotatably mounted-about the column forming the working structure 111 while being arranged in coaxial relation to the revolving head 122.
Figure 8 shows the behaviour of such a system under the action of the swell in particular when the column forming the working structure 111 is connected to the sea bed through the agenoy of a pivotal connection forming a universal cardan joint coupling as is well known in the prior state of the art. When the working structure is tilting from the vertical direction under the influence of the swell the parallel-motion linkage or parallelogram defined he~inabove would deform itself thereby avoiding giving rise to excessive stresses or strains while retai~ing the emerging arm 120 and especially the gas flare 112 above water level.
Figure 9 shows another alternative embodiment wherein the holaing maRt 115 may be rigidly connected to theemerging arm 120 and extends at ~6562:4 right angles thereto (the pivotal connection 125 being omi-t-ted). Moreover, there should be provided at least one lacing bax or like triangulation element 134 forming a brace, strut or like stay member mounted in diago-nally extending relationship between a point 135 of the emerging arm 120 preferably near the working structure 111 and the holding mast 115 in par-ticular at a location adjacent to the float or buoyant member 114. ~he assembly between the emerging arm 120, the holding mast 115 and the trian-gulation element or lacing bar 134 may however also be effected by means of pivotal connections, the triangular configuration thus achieved being not deformable.
It should be pointed out tha-t the holding mast 115 may be as~embled to the emerging arm 120 in extension of or in aligned registering relation-ship with the gas flare 112 i.e. at one end of the emerging arm 120 as shown in ~igures 5 and 9 but also and preferably at an intermediate point thereof as clearly seen in Figures 6 to 8. ~hus the remaining portion 136 of the emerging arm 120 carrying the gas flare 112 is mounted as a canti-lever framework in overhanging relationship with respect to the holding mast 115 thereby enabling the construction of the beam 119 to be of redu-ced weight. It should also be noted that the pivotal connections 118 and 127 in the case where the working structure is stationary and does not include any rotary or swivel head preferably are of the ball-and-socket joint type. Advantageously the pivotal connection 118 is hollow to form a passage-way for the flow paths or travel of fluids or ducts such as 117a, 117b.
~ he gas flare arrangement connected to a working structure such as just described according to the present invention is of a cost price sub-stantially lower than any prior art system and in addition axhibits a very high operating reliability to the extent where the gas flare 112 may be located at a distanoe of more than hundred mz~rs away from the working stru¢ture without the passage-way lines for the gases to be burnt contac-ting the sea.
It is to be understood that the invention should not be construed as limited to the embodiments of equipment just described since it comprises any technical equivalents of the means provided if the latter are used within the scope of the appended claims.

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Claims (18)

The embodiments of the invention in which an exclusive property or pri-vilege is claimed are defined as follows :

1. An off-shore oil field production equipment with a production platform in particular anchored to the sea bed of the drilling site, including an articulated column pivotally connected through a univer-sal cardan joint coupling to a base member anchored to the sea bottom and in connection with a remote-located floating gas flare for burning gases extracted from crude oil, wherein the improvement consists in that said gas flare is carried by a floating structure coming up in-to the wind and connected to a rotary head of the column by means of a pivotally connected support.

2. An equipment according to claim 1 having a production column connected at its base member to a plurality of wells, wherein said equipment comprises oil and gas separator means, a remote-located gas flare for discharging said gases with the scrubbed oil flowing down to said base member for being conveyed to a remote-located storage tank anchored to the sea bed, said storage tank belonging to a lading plat-form.

3. An equipment according to claim 2, wherein said base member constitutes a storage tank.

4. An equipment according to claim 2 used in connection with se-veral wells and comprising a combination platform the base member of which anchored to the sea bed is designed as a storage tank whereas the well heads are extending therethrough and projecting upwards the refrom.

5. An equipment according to claim 1, wherein the flare carrying floating support consists of a braced and trussed arm assembly of tu-bular construction forming float means.

6. An equipment according to claim 1, wherein said floating sup-port is pivotally connected to arm means themselves pivotally connected to the head of said platform.

7. An oil field production equipment according to claim 1 having a gas flare associated with a sea bed working structure and carried by a floating support, wherein said floating support consists of at least one submerged float stopped by an emerging holding mast bearing said gas flare.

8. An equipment according to claim 7, wherein said holding mast is connected to a rigid or stiffened supply piping for feeding said gas flare, said piping comprising an approximatively horizontal por-tion pivotally connected to said working structure.

9. An equipment according to claim 8, wherein said piping is se-cured alongside of a latter beam so as to form therewith an approxi-matively horizontal emerging arm.

10. An equipment according to claim 9 with a working structure consisting of an oil field development column connected to the sea bed and provided at its emerging top portion with a substantially coaxial revolving head, wherein said emerging arm is pivotally connected to said revolving head.

11. An equipment according to claim 9, wherein said working struc-ture is a platform.

12. An equipment according to claim 9, wherein said working struc-ture is a ship such as a tanker.

13. An equipment according to claim 9, wherein at least one la-cing bar forming a bracing element is mounted diagonally extending relationship between one point of said emerging arm near said working structure and a point of said holding mast adjacent to said float.

14. An equipment according to claim 9, wherein said holding mast is pivotally connected to said emerging arm.

15. An equipment according to claim 14, wherein said floating support is provided with a ballasting mass.

16. An equipment according to claim 14, comprising an approxi-matively horizontal submerged arm pivotally connected with both of its ends to said working structure and to said holding mast, respecti-vely, thereby substantially defining a parallel-motion linkage forming a deformable parallelogram with said emerging arm, said holding mast and one portion of said working structure.

17. An equipment according to claim 16, wherein said submerged arm is pivotally connected to a rotary ring-like collar rotatably mounted about said column in substantially coaxial relationship with said revolving head.

18. An equipment according to claim 9, wherein said holding mast is assembled to said emerging arm at an intermediate point thereof, the remaining portion of said arm which carries said gas flare being thus mounted as a cantilever beam in overhanging relationship with respect to said holding mast.