US3194315A - Apparatus for isolating zones in wells - Google Patents

Description

July 13, 1965 N. J. ROGERS 3,194,315

APPARATUS FOR ISOLATING ZONES IN WELLS Filed June 26, 1962 3 Sheets-Sheet 1 v Nolan \l. Rogers 1 N VEN TOR.

' July 13, 1965 N. J. ROGERS 3,194,315

APPARATUS FOR ISOLATING ZONES IN WELLS Filed June 26, 1962 3 Sheets-Sheet 2 Nolan .1 Rogers INVENTOR.

July 13, 1965 N. J. ROGERS 3,194,315

APPARATUS FOR ISOLATING ZONES IN WELLS Filed June 26, 1962 3 Sheets-Sheet 3 a2 ii-52:: 553' 1- 88 i i: I I L Z-iii:

Y 4-: all: [Mi-"1 szl 1 51i: 90 ii! z 34-! wi E:

,u 7 9? i I50 I g l 94 Z- /4 a 26 I 20 2,22 v 4 iw A 32 Nolan J Rogers INVENTOR.

BY .nmwbg United States Patent Filed June 26, 1962, Ser. No. 265,261 14 Claims. (Cl. 166--57) This invention comprises a novel and useful apparatus for isolating zones in wells and more particularly pertains I to an apparatus by which selected portions of a well bore and the formation contiguous thereto may be effectively isolated from the remainder of the well bore and formation by freezing the liquid in the well bore at these locations and in the adjacent formations to thereby provide a barrier preventing communication and flow into or out of said selected port-ions of the wellbore and formations.

It is frequently desirable to isolate selected regions in a well bore and the formation zones contiguous thereto for various purposes. The present prevailing practice of i11 setting a mechanical plug in the well bore such as a seal or packer to effect a fluid tight seal with the wall of the Well bore is accompanied by many disadvantages and difficulties attending the installation of the packer or seal, interruption to flow of fluid in the well during the installation of the packer or seal, and the subsequent removal of the packer or seal when its services are no longer required. Since these difficulties are well known to those familiar with oil well and other deep well operations, a further "and more specific discussion of them is deemed to be unnecessary for the purpose of this invention. It may be noted however, that these undesirable conditions are even more prevalent when it is desired to conduct a series of tests in a Well bore for selectively isolating different zones thereof to determine the flow characteristics or the production from individual zones, since this necessitates a repeated establishing of a series of seals to isolate selected zones in order to test the production or flow of the latter, and then remove the seals to repeat the operation at other zones.

It is therefore the primary purpose of this invention to provide an apparatus which will greatly facilitate the isolation of selected zones in a well bore and in the contiguous formationpenetrated by the well bore.

A further object of the invention is to provide an apparatus which will enable the establishment of a seal and the removal of the latter when its use is no longer required, to be effected with ease and certainty regardless of the may be applied at a selected region in a Well bore to effect freezing of the drilling fluid therein and in the contiguous formation in order to establish a seal and thus isolate a selected zone.

And a final important object of the invention to be specifically enumerated herein resides in the provision of an apparatus which will enable the freezing of the drilling fluid to effect the establishment of a seal and the thawing of the frozen drilling fluid when it is desired to release the seal and which will in no way interfere with the use of other types of seals where desired.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a fragmentary view in vertical section through a well bore in a formation and indicating the manner in which the principles of this invention are to be applied thereto; v

FIGURES 25 are successive views taken upon an enlarged scale and in vertical central section through the apparatus of this invention respectively upon the planes in dicated by the section lines 22, 33, 44 and 5-5 of FIGURE 1 and showing the position of the parts of the apparatus in their inoperative or non-sealing positions;

FIGURE 6 is a detail view in horizontal section taken substantially upon a plane indicated by the section line 6-5 of FIGURE 3;

FIGURE 7 is a detail view in horizontal section taken substantially upon the plane indicated by the section line 7-7 of FIGURE 5;

FIGURE 8 is a further horizontal section taken sub stantially upon the plane indicated by the section line 8-8 of FIGURE 5;

FIGURES 9 and 10 are detail views illustrating the operation of the device; and

FIGURE 11 is a group perspective view of the actuating means for initiating operation of the seal forming portion of the apparatus.

Referring first to FIGURE 1 it will be observed that the numeral 10 designates a well bore extending through a subterranean formation to a strata 12 which it is desired for any of various reasons to isolate from the Well bore and the rest of the formation. In accordance shape or configuration of the well bore at the site which is to be sealed. v

A further object of the invention is to provide an apparatus which will enable seals to be readily applied to selected regions of a well bore without necessitating the use of heavy, cumbersome, and time requiring equipment and techniques of installation and removal of the seals.

Yet another object of the invention is to provide an apparatus whereby a self-contained seal establishing unit or units may be mounted in tubing or pipe strings and which will not interfere with the flow through the string until such time as it is desired to effect the establishment of or the release of a seal at a selected site.

A still further object of the invention is to provide an apparatus which will enable a seal to be quickly established or released from a selected site in a well bore for isolating a selected zone or region and wherein the operation of establishing or releasing the seal may be entirely effected and controlled from the surface.

A still further object of the invention is to provide an apparatus which will enable the use of drilling fluid to initiate the sealing action and to effect a release of the seal when desired. I

More specifically, it is a further object of the invention to provide an apparatus whereby a refrigerating effect i to the desired location therein.

with this invention a refrigerating device indicated generally by the numeral 14 is attached to the lower end section 16 of a drilling string, a tubing string or a pipe string of any desired character whereby the refrigerating device can be positioned and moved in the well bore When so placed, the refrigerating device heretofore kept inactive is rendered active in a manner to be subsequently set forth whereby it will produce a refrigerating action which will freeze the liquid in the well bore on opposite sides of the selected zone in the well bore and the contiguous region or strata 12 which is to be isolated. This refrigerating action will freeze the liquid between the refrigerating device and the wall of the well bore so as to produce plugs of frozen liquid in the well bore and in the contiguous portions of the region adjacent thereto and thus effectively seal and prevent any flow through the well bore from or into the selected region or strata. the provision of suitable conduits extending through the refrigerating device and opening into the selected strata or region of the well bore, various operations such as testing, acidizing or the like can be employed while the frozen seals are maintained in place. Thereafter, the frozen seals may be allowed to thaw or may be caused to thaw by circulating a heating medium in heat ex- V I change relation therewith thus completely "removing: the closure seals and permitting the resumptionof flow through' the Wellbore:

Reference is now madel specifically ;to FIGURES 2-5 for a description of a preferred'and suitable formof re f ,iags ej ing actionas set forthhereina frigerating apparatus in accordancewith this invention The refrigerating device 14 consists of anelongated body of a sufficient diameter tobe readily inserted into or removed from a well bore and moved along the well borejto and from a selected region or location. 7 Although it maybe of ,arone-piece or unitaryIconstruetion," it is preferably formed of afplurality "oi sections detachably secured together and which preferably 7 have a smooth cylindrical continuous exterior surface 'of runiforrn die anieter throughout. Thefbody'cof' the refrigerating device consists of a lower section 2%, seeFIGURflE 5,"ha v-' ing" a refrigerant storage chamber 22 therein and hav-. 7 l ing a screw threadedly engaged plug or, closure bottom 'wall 24 therefor. "of the lower section of the storage chamber sectionthe latter is providedwith a partition 26fthereacross which" Adjacent but spaced from the top separates'the storage chamber 22 from .a'refrigerant de livery chamber'28, with the. partition as having passage} meansestablishing communication between the chambers 22 and 28 asfset forth hereinafter.

' A {discharge piston; 30; has a fluid tight; slidingfseal and engagement with the wall of the refrige rant stormeans of a ma threaded eng lpose; thesecti'on 56 has j a diametrically extending aily elongated boretit) therethroughfandwa.;pair of;

\ are slidable in; the 1 diametrica'l bores orsloitsiob. LjThese fterlto be pos toned on opposite sidesiofjthis ioneand region; r I r Referring now to FiGURE Zitw/illbe observed that theaadapterseotion S ZVand .thelmember aref slidably supported. by {the connector sectioni585' For this ur taining pins e2" a chithreadedly e ngaged in .thejsleevefdg pins engage-the Stem ofaffcoll'ar i beleyv the latem ity pport this cel ".therethrough r fl pper endless consist of a single 'mernee secured together.'-' This tube iding engagement in t the bore 7st or thesbottom walllo er the adapter sec- V- 1 tiorr52, 'andan O-ringior other sealingimeans tas 784 i y, p jQ Cl ins re a fluid Qtight ,asealedjl engage ment' where the tube passes throughithei-borel-l17d; [If

Atjits lower end, the tubular tubing 72 is connected as V by a coupling memberj tito afnrther tuhefiiwhich likei age chamber 22jiand is moved upwardly-under the -influence of'the pressure in they liquid within the'well bore andwhich'communicateswith the bottom side of the piston 3'6v by means ofthe'inlet passage 32., Come-. quently', as liquid refrigerant is delivered from the'eham-j ber 22 the pressure of the liquid inthe-well' bore -enter-,

ing the passage means 32 ;;will force. the piston-69 up:

" wardly andfassist'inexpelling refrigerant liquid vfrom the; 7 'ch'ambe'rll a At, its upper end, thelower section 2d islinternally threaded at 34 to receive therein a pair of spaced eze ternallythreaded plates 36 and 38. Above the plate 36,.by means of tapering internal threads dih the. lower chamber 46. Continuing downward from t wise has'a sliding engagementintheibore 34o thetranse verse partitioned-at the lower end of thdupp pension.chainbersseotion '46,:the tubeemember 82 extends through the spacer section or sectionstddihaving a sliding section 26 is secured to the externally threaded portion of. a section .42 which comprises vla lower expansion chamber of the refrigerating device 7 a At its upper end; the lower expansion chamber 'se'c V i' tion 42 is internally threaded and thus is, secured .to'

the lowerendofa spacer section44 of any desired length.

y This spacer section may consistof a singlepipe section V or, .a plurality ot 'su'ch sections joined together in order to provide ,therequisite length as will be apparent here:

inatt'er. t

As shown in FIGURE 3,"the uppermost portion of the; spacer section orsections 44 is internally threaded'and f engages the, lower end Of: an upper, expansion chamberg section 46."-At its" upper end, ,the l'atter is internallythreaded to engage-the connector or coupling memberv 48threaded1y secured ,to the lower :endgof a further 7 section 50. The ,latt ertin turn is internally threaded to= engage an adapter section 52whose upper, endfis inter-ts- -nallyv threaded 'and receives thereinthediametrically;

enlarged flanged extremity 54 of a section or member" 56. The'latter is slidably' received in the axial bore of.

a sleeve or coupling-member 58twhose upper end is threadedly engaged upon the lower extremity of the;

string 16. t 1 'Whenthe sections are assembled upper expansion chamber; section 45 in orderto obtain any desired spacing between :these "twoexpansionsectionsrand thus enable them, as ishown in PIQURE l,

to extend through the zone mtgthe well bore and, the, contiguous region of therstratalz to enable refrigerate in this manner, as. sho Wnlin FIGURE 1, the entire refrigerating device can i be handled as a unit. It will be understood that appriate lengths; of spacer; sections Mimeinterposed between'the lower expansion chamber section dZVand' the V j bore between; the uppenand lowerexpansi'onlchamberjSec- .tions of thedevicei, v In this manner; fluid can 'be with- "o'ffthe lower expansion chamber, section. The tubea tIits;

, befpassed downwardly V ber sections 4 6 and 42;; netube is' pr'ovided with a port g in th'e wail ior a itionae'o'rth s when the; tube is. appropriately;position as a meansforsupplying various agents toz thefofmationq this chamber arelined with aniexpansion coiljllti.

engagement in a bore i'girieach of the transverseqwalls 9t of these sections; I From thence the tube; section 8; extends downwardlythroughltl ie bore @Zpin anaest esia partl V tron 94, secured in the upperport'ioniof the lower expan-nr' sion chambeiysection iz--as; byi oifa pairfoffsplit' rings each "i'ndi'cjated'M1961:tContinuing downwardly through the lower expansion chamber-section theltube' is slidablyreceived in; the bore 980f the bottom wall P ;5

lower end extendsflthrough aligned bores'inthe two plates 7 36 and 38 and istprovided with a closure plug or cap 192' at its lower, end which liesin'the refrigerant delivery cham bers," it f' communicates' directly; with-Tithe interior lot the 7 ring 16 byi me'ans of wh ch'yarioiis liquidsForfluidsmtiyf I hr'ough: the tube to 'eifectyvaiious', k hicliare'setforthhereim; g p W efof'thefspacersections" dwhich lie-betweenthe l ppergandflowerexpansion'eha Mil which is adapted toregister iwitl a 1321553226511 a lyff V de'viceso that the portfitt will register withthe passage 11-2; :communic'ationjis established nam sake; interior of 1 V theIjtube and thejinteriorof the string: l andlt well, 7

drawn from a selectedj region of the ,borerwith which the passage 112 registersffor testing or,-otherfpurposesorn liquids ,can be applied to-thelviell boreattthe selected zone, a I by being forced downwardly through theitubef; V V '7 V In addition to itsfunctionsjofserving a s'na flow tubeito, i receive fluid from a se lected portion'ofjthe'welkbore; and.

from the'snrface, the tube, also seryes as a means vto control thelrefrigeiatingaction;ofgthedevice;- V a In eachof theexpansion chambers thereis provided-ans 5 I j expansion coil.;, Thus, the lower: expansion.casingidfi has T a lower expansion chamberl l llthereinandj the wall of similar manner, the upper expansion chamber section 46 has an upper expansion chamber 118 therein and an upper expansion coil 120 is disposed in this chamber. A refrigerant delivery tube 122 has its lower end threadedly engaged inthe bottom wall 160 of the lower expansion chamber section 42 where it communicates with a refrigerant passage 124. This passage in turn communicates with a valved outlet passage 126 extending through the upper plate 36 and which thus communicates with the valving chamber 128 disposed between the two plates 36 and 33. A further passage 130 extends through the lower plate 38 and has continuous communication with a valving chamber 128. Aligned with the passage 126 in the lower plate 38 is a valve bore 132 in which is slidably received the lower end of the'refrigerant control valve 134. As shown in FIG- URE 11, this valve is a cylindrical body having a diametrical slot 136 therethrough in which is slidably received an actuating member in the form of a cam finger 138 carried by an actuating piston 149. The latter slides in the valve actuatingchamber formed between the plates 36 and 38 so that, as shown particularly in FIGURES 5 and 10, fluid presssure to the right of the piston 14% will drive the latter towards the left. Owing to the engagement of the cam finger 138 in the slot 136 of the control piston 134, the latter will be reciprocated in its piston bore 132. As the piston 140 moves towards the left, the valve is shifted downwardly. so that its upper end will uncover the seat at the lower end of the passage 126 thus establishing free communication'between the delivery chamber 128 by way of the passage 130, the valve chamber 128 and the passage.

126 to thepassage 124 and thus to the interior of the refrigerant delivery conduit 122. Pressure fluid is supplied to the right side of the piston through the previously mentioned tubes 72,82 and a port 142 in the lower end of the tube section 82 which registers with the actuator chamber in which the piston 140 is transversely slidable through an aperture partition 141 comprising an end wall for the actuator chamber. Any suitable means may be provided for effecting the return of the piston to the right end of this chamber and thus etfect the lifting of the control valve to its seated or closed position cutting off communication between'the valve chamber 128 and the passage 126.

It will thus be apparent that by applying a predetermined pressure to the interior of the tubes 72 and 82, the

control valve maybe opened to permit the discharge of refrigerant from the delivery chamber 28 into the delivery conduit 122.

From the delivery conduit, at the lower end of the tube 122, the lower expansion coil 116 is connected as by means of a coupling 144-. At its upper end, the expansion coil 116Jas shown in FIGURE 4 is connected at its extremity 148 to a discharge conduit which latter is securedin the partition member 94 and extends therethrough, through the partition 90 of the spacer unit or units 44,,and finally as shown in FIGURE 3 through the upper expansion chamber where it terminates and opens into the upper end of the latter.

It will be further apparent from FIGURE 3 that the refrigerant delivery conduit 122 at its upper end terminates in a bore in the partition fi of the upper expansion chamber section 46 and the lower end of the upper expansion coil 120 is connected as byafittiug 152 and passage 154 with the bore 156 into which the upper end of the delivery conduit 122 extends. The upper end of the upper expansion coil 120, terminates as shown at 158 in the upper end of the upper expansion chamber 118. Thus the two refrigerant expansion coils discharge at the upper end of the upper expansion chamber and into the auxiliary expansion space 160 of the section 50.

As will beappreciated, during this expansion of the compressedrefrigerant,the latter will absorb heat and thus effect a chilling or refrigerating action thus causing the liquid in thewell bore adjacent the upper and lower expansion chamber sections to be frozen solid and form a plug or seal in the well bore at these locations. It will be appreciated that this seal is formed independently of the nature of the well bore itself, that is, it is not dependent upon the bore being of uniform size, shape or physical characteristics.

Referring now to FIGURES 5 and 8, it will be observed that the partition 26 of the refrigerant storage section 20 has a passage system of any convenient character such as that indicated generally by the numeral 161 therethrough by means of which refrigerant from the storage chamber 22 may pass through the partition 26 and enter the delivery chamber 28 to be discharged therefrom under the control of the control valve as set forth hereinbefore.

It is believed from the foregoing that the operation of the apparatus will now be readily apparent. With the storage chamber charged with a liquid refrigerant under pressure such as liquid oxygen or the like, and with the parts in position shown in FIGURES 2-8, the refrigerating device, connected to the string 16 is introduced into and lowered in a well bore until the device reaches the desired location therein. For this purpose, the spacer section 44 of the device is of appropriate length to extend entirely across the zone in the bore and the region in the contiguous formation which is to be isolated. It will be observed that this operation can be effected while drilling mud or other fluid is being discharged by means of the tube 72, 82 and the open port and passage 110, 112 in the manner shown in FIGURE 9. Thus, the device can be installed during a drilling operation if the string 16 is a 'region of the strata 12 from the well bore.

drilling string. With the device installed, that is, properly located with respect to the zone in the bore to be isolated, it is merely necessary to increase the pressure within the tubes 72, 82 to the desired extent. This will cause the piston 146) to be moved towards the left as viewed in FIGURE 5, until the piston assumes the position shown in FIGURE 10, at which time the same actuating finger 138 will open the control valve 134 to the position shown in FIGURE 10, at which time the cam actuating finger eraut from the storage chamber upwardly through the passage system and to both of the refrigerant coils. As the liquid passes through the refrigerant coils and drops in pressure, it will expand and absorb heat, being finally collected in the chamber 160. During this expansion, the liquid will freeze the well fluid or the drilling fluid or other liquid in the well bore which surrounds the two upper and lower expansion chambers. This will produce a solid seal obstructing any fiow of fluid through the well bore and thus completely isolating the selected zone or By now releasing the pressure which was just applied through the tubing 72, '82 in order to actuate the control valve and by forcefully moving the member 53, the shear pin or shear disk 70 will be sheared. This will have the effect of the member 58, and the tube 72, 82 moving upwardly with respect to the members 54, 52 and the sections which lie therebeneath so that the inlet portion of the tube 82, indicated by the numeral 176 registers with the passage 112 and permits fluid to be introduced from the tube into the isolated zone for treating the latter, or permits fluid from the zone to be withdrawn through the tubing for testing purposes.

Thereafter, the frozen plugs produced by the refrigerating'action may be allowed to thaw or such thawing may be facilitated and hastened by circulating heated drilling fluid through the tubing 72, 82. This will completely remove all sealing means and restore the well bore to its original unimpeded flow condition.

The foregoing is considered as illustrative only of the principles of the 1 invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to'limit the invention to the exactconstruction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

" What is claimed as new is as follows:

1. An apparatus for use in a well bore having therein. a freezable liquid, for temporarily closingsaid well boreon opposite sides of a selected'region to be isolated, said apparatus comprising a refrigerating device sealed from the atmosphere, said device comprising a plurality of V connected sections including apair of-refrigerating sec tions each containing therein in 'goodiheat transfer rela-j 'tion therewith a retrigerantiexpansion chambeniavspacer a section interposed between said refrigerating sections and t of sufiicient length for positioning the latter'upon opposite sides of said selected region, a refrigerant storage section having therein a refrigerant storage chamber storing .a

refrigerating fluidunder pressure, at least-one of said" plurality of sections having therein an exhaust'charnber; refrigerant delivery-means conducting refrigerant from y said refrigerant storage chamber'to each of said expansion chambers and refrigerant exhaust means conducting refrigerant from said expansion chambers; to said exhaust chambers, a control valve-assembly interposed inzsaid refrigerant delivery means "and having a control valvescontrolling flow'of refrigerant through said expansion chambers, an actuator means connected to said control valve and efiecting positive opening and closing of thelatter jat selectively controllable times from the surtacei of the ground. v a i v '2. The combination of claim 1 including'a pipestring to which said apparatus is connected and supported and whereby said device may be maneuvered and positioned in a' Well bore, said actuator means being controllable through said pipe string.

3. The combination of clairn'l including passagemeans in said spacer section establishing communication .with said selected region to be isolated, 'a valve controlling i said passage means. i i

dfiT-he combination'of claim '3 including a tube ex-i releasable retaining means engaging said tube and pre-z Venting registryofsaid'registrableportsf 5. The combinationicf clairnl Whereinsaid expansion Y chambers each co'mprisean expansion coildisposed in, one" of said refrigerating sections, said'expansion coils being connected in parallel relation to: said refrigerant delivery means.

' 6. The combination of 'claim 5 wherein each expansion tending through said refrigerating and 'saidspacer; sec-"- tions and being slidabletherein, said 'passage means in-i eluding registrable ports in' said tubeand spacer section,

' ing pressureftosaid actuator; v a Z si 13.1Airyapparatusliter-isolating akseleictedgzone in a;

1 well bore having a liquid therein comprising an elongated refrigerating device adapted toriztmovement; in a mall;v bore to and fromxsaidrselectedizone; said device ncludin'gij coil has an outlet separatelycommunicating with said exhaust chamber. j

7.'The combination of claim site ends of said" refrigerating sections. a

8. The combination of claim 1 wherein saidcontrol I llwherein said exhaust} chamber. is disposedin an exhaust section, said exhaust and refrigerant storage sections being positioned at oppo' valve assembly includes av-alve chamber having an inlet in continuous communication with said refrigerant stor-E; age chamber andan outlet communicatingwith said ex- 'p'ansion chambers, saidicontrol valve being mounted tor movement in said valve chamber and \,controlling said said actuator element tosaid valve.

'9. The combination of claim .8 wherein said actuator" element consists of a reciprocating piston, said connecting meanscomprising a cam finger on said piston an'da slot" in said valvereceiving said cam'sfinger; said piston and cam finger being movable transversely oftheline ofj:

movement of said valve.

10. An apparatus; forisolating a' selected zone in ,a' Well bore having a liquid therein comprising a refrigerat- 1 ing device adapted to be moved ina well'bore to. said outlet,'said actuator means including an actuator elemerit, meansapply'ing fluid pressure to said, actuator element and effecting movement of th latter, means connecting'f forcontrolling refrigerant flowbetween said chambers said controlrneanstincluding a control :yalveioperativelvf, interposed between saidst-orage chamber and said delivery l irneans, a fluid pressure operated vactuator iconnected; tol 'said Control valve,?means for applying'fluid underactuat-j selected zone, said device iricluding a storageljchamber I means for V a' retrigerant :under. pressure; m ns :defining refrigerant expansion chambers spaced frlornj"eachv other a distance sufiicient' to enable positioning of 'said"ex-; g pansioni chamberslin said Welliborejon opposite sides nof said "zone; means nfo'ndeliveri'ng refrigerant {from said;

storagechamberf to said expansion 5 chambers,- F control} 7 means; operative to'control'fiovvofrefrigerant"from 'saidstorage chamber-to saiddelivery means; each expansion chamber; havingl an expansions-coil therein, said delive'ry means comprising a conduit extending-into" both said and being 'connected tov-thejexpan'sion expansion chambers coils therein.

@ 11. An apparatus: for isolating ;.,a selec ted z one :inya o well borej'h'aying-a' liquid-therein comprising .a refrigerat ing device adaptedto -be moved ina;wellbore}to said selected 'zone; said I device including ,a storage reharnbefi rmeans for a refrigerant under pressuregfnieansj defining refrigerant expansion chambers. spaced vfrom 53611 other; 1 a distance sufiicient to enable positioning of saidex an, r y sionchambers in said well bore ionlopposite sides of fsaid 1 zone,means fortdelivering refrigerantfrom' said storage chamber to' said expansion chambers; control means: op

erative ito "control how of I refrigerant from jisaidi "storage chamber ,to said deliverjy means; said control means *including a-control valve'.operatively -interposed{between V a said storage" Qhem'ber" and said. delivery means, a-fiu'id pressureoperated actuator conn'ected torsaid controlvalve meansyforrapplying fluid under actuating pressure to said I actuator;

f '12.; An apparatusforternporarilyclosingiikwellibore r i at a selected region comprising' a;refrigeratingdeviceadapted for movementto a selectedregion in a well bore; having a liquid therein; said device including achaniber; 7

means tor-storing a refrigerantunderipressuregandfrheans' defining. an expansion chambertiior selected regiongmeans-rjtor deliveringfretrigerant'ffrom,

os'itioning at: said;

said storage to said expansionchamber;rcontrolsmea a unitary body having therein separate upperand vbore.

14. The combination of claim including means' forll applying fluidunder pressure from said conduit to saidf v controlmeansb a V Re f erencesfCited bythe i Un-rrnoisrnrns'f PATENTS 2,033,561f 3/36 Wells

Claims (1)

12. AN APPARATUS FOR TEMPORARILY CLOSING A WELL BORE AT A SELECTED REGION COMPRISING A REFRIGERATING DEVICE ADAPTED FOR MOVEMENT TO A SELECTED REGION IN A WELL BORE HAVING A LIQUID THEREIN, SAID DEVICE INCLUDING A CHAMBER MEANS FOR STORING A REFRIGERANT UNDER PRESSURE AND MEANS DEFINING AN EXPANSION CHAMBER FOR POSITIONING AT SAID SELECTED REGION, MEANS FOR DELIVERING REFRIGERANT FROM SAID STORAGE TO SAID EXPANSION CHAMBER, CONTROL MEANS FOR CONTROLLING REFRIGERANT FLOW BETWEEN SAID CHAMBERS, SAID CONTROL MEANS INCLUDING A CONTROL VALVE OPERATIVELY INTERPOSED BETWEEN SAID STORAGE CHAMBER AND SAID DELIVERY MEANS, A FLUID PRESSURE OPERATED ACTUATOR CONNECTED TO SAID CONTROL VALVE, MEANS FOR APPLYING FLUID UNDER ACTUATING PRESSURE TO SAID ACTUATOR.

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