US2911048A

US2911048A - Apparatus for working over and servicing wells

Info

Publication number: US2911048A
Application number: US460864A
Authority: US
Inventors: Iii James R Dublin; John W Kenneday; Wallace M O'reilly
Original assignee: Jersey Production Research Co
Current assignee: Jersey Production Research Co
Priority date: 1954-10-07
Filing date: 1954-10-07
Publication date: 1959-11-03
Anticipated expiration: 1976-11-03

Description

5 Sheets-Sheet 1 F/G. 3. FIG. 4.

`J. R. DUBLIN lll ET AL APPARATUS FOR WORKING OVER AND SERVICING WELLS Nov. 3, 1959 Filed oct. '7, 1954 F IG.

James R. DublnlZZ, BY John W Kenneday, Wa/lace M. OReIIIy,

A rra Nov. 3, 1959 J. R. DUBLIN nl ET AL APPARATUS FOR WORKING OVER AND SERVICING WELLS Filed oct. 7

3 Sheets-Sheet 2 Il lxiilillllilin IIIIIIII FIG FIG. 5.

IIVENIORS, James R Dub/mill neday, BY Wal/ace M. O'ReIIIy,

John W. Ken

A TTO RN Nov. 3, 1959 J. R. DUBLIN' m Em 2,911,048

APPARATUS FOR WORKING OVER AND SERVICING WELLS 3 Sheets-Sheet 3 Filed Oct. 7,

FIG.

OR 121 John W. Kenneday,

INI/EN James R. Dub/ln lllllllll. :I c

UnitedStates Patent() APPARATUS FOR 'WORKING OVER AND SERVICING WELLS James R. Dublin III, John W. Kenneday, and Wallace M. OReilly, Houston, Tex., assignors, by mesne assignments, to Jersey Production Research Company, Tulsa, Okla., a corporation ofDelaware Application October 7, '1954, Serial No. 460,864 13 Claims. (Cl..'166115) The present invention is vdirected to apparatus for working over and servicing wells. More particularly, the invention is concerned with conducting operations in wells penetrating a plurality of productive' intervals. In its more specific aspects, the invention is directed to apparatus for obtainingproduction from a plurality of productive intervals.

The present invention may be brie'y described as involving apparatus for working over and servicing a well having a casing arranged therein and provided with a tubing having its lower open end arranged at a level in said casingabove a plurality of productive intervals penetrated by said well. In one vconception the apparatus vcomprises irst `andsecondspaced V`apart supporting means arranged in the tubing adjacent the lower end. .The tubing has a valve means adjacent the spaced apart supporting means which may be provided between said spaced apart supporting means or `may vbe arranged below the lowermost of the supporting or securing means. A first tubular extension member is arranged in the tubing andsupported by the rst supporting means and the lirst tubular extension member projects from the openlower. end of the tubing to increase or vary the effective length of the tubing. A second tubular extension member of smaller diameter than the first tubular 'extension member is arranged in the tubing and supported onthe second supporting means above the first'supporting means. The

second tubular member is arranged within thevirst tubular member and is Vat least co-extensive therewith for the length of the first Vtubular member. The lower end of the tubing'is provided with'a packing means isolating the annulus between the tubing and the casing above the rst packing means. A second packing means below the lower end of the tubing cooperates with the first tubular extension member* to isolate a zone in the casing below the second packing means. The second packing means is provided with a guide means for the'iirst tubular member.

The second tubular member ydefines a passageway from the tubing to a level in'the well below the second packing means and the first tubular member defines a passageway from the level in the well below the second packing means into the tubing and through the valve means into the annulus. A by-pass means, which may be employed at i option and which may be arranged in the second packing member or in the tubing below the first supporting means, provides circulation from the zone between the two packers to the annulus.

- The invention also comprises working over and servicing a well completed in a plurality of zones having a casing and provided with a tubing arranged with its vlower open end above a plurality of productivezones in which production is being obtained through perforations in said casing from aplurality of said zones. `rThe invention comprises terminating Vproduction frornlsaid zones and flowing a liuid into .atleast a portion of theperforations in at least one of said zones and then obtaining production'y vfrom said zones at least through-perforations in the ,2 casing vertically displaced from the perforations into which the fluid has been flowed.

The fluid which is flowed into the perforations may suitably be a cement slurry, such as a cement slurry as encompassed in the patent to Salathiel, U.S. 2,482,459, orthe fluid may be an acid such as a mineral acid as illustrated by hydrochloric acid, sulfuric acid, nitric acid, hydrouoricacid or mixtures thereof. The acid may be inform ofla gel as maybe desired.

The uid'mayalso be a fracturing fluid such as described in FrenchPatent 987,352, published August 13, 1951, and may suitably contain a bodying or weighting agent such as sand but whichsuitably maybe an oil, such as distillate, crude oil, and/or fractions thereof. The fluid may be a washing liquid, such as fresh or salt water, and may suitablybe used toremove debris, such as sand, and the like, from the well. ,v It is contemplated in the practice of thepresent invention that after selected perforations have been sealed or treated, such' as sealed with a cement slurry ofthe type mentioned, either .or both of the zones so treated may be perforated and production re-established or resumed therefrom. v f

In the practice of the present invention it is contemplated that the zones may be worked over or serviced by conducting cementing operations to seal off perforations, acidifying operations to open up hydrocarbon productive intervals, and vfracturing operations to increase the permeability of lowpermeability formations or simply to improve or increaseproduction of desirable hydrocarbons. It is contemplated that washing operations, such as removing sand from the well or washing out a cavity back of the casing, may be conductedv in the present invention.

One conception of the present invention will be further illustrated Yby-reference to the drawings in which:

Figs. 1 to 3 show an arrangement of apparatus for conducting the present invention;

Fig. 4 is a view similar to Fig. 1 showing reperforation of=a zone below a lower packer;

Fig. 5 shows perforating in a Zone between spaced apart packers; v

Figs. 6 to 8 show a front elevation and arrangement of apparatus for conducting the present invention omitting elements of Figs. 1 to 6; and

Figs. 9 to 11 show a front elevation of an arrangement of apparatus for carrying out the present invention.

Referring now to the drawing in which identical numerals will'be employed to designate identical parts, numeral 11 designates a well bore drilled from the earths surface and extending through a plurality .of intervals, strata, formations or Zones A, B, C, D, E, F, G, and H, with the zones or intervals A to E being in one yproductive horizon and Zones F to 'H generally in a lower productive horizon penetrated by the well 11. Arranged in the borehole or well 11 is a casing 12 which is cemented in place with kprimary cement 13. A tubing string 14 extends from the earths surface to a level above the interval or formation A and is provided with a lower open end 15. The annulus 16 between the tubing 14 and the casing 12 is closed off by a packer 17 which may be a packer such as illustrated on page 942, vol. 1 of the 1952-53 Composite Catalogue, nineteenth edition, as the Duo-Pack Packer of the Brown Oil Tool Corporation, the inner mandrel of which is connected into and forms part of the tubing 14. The tubing has arranged adjacent the lower end thereof a irst supporting means 18 and a second Vsupporting means 19 which is spacedapart from the-supporting means 18. This supporting means may be a landing nipple, ksuch as.

' illustrated 4at page4063 of the Composite'Catalogue,

Patented Nov. `3, 1959 supra, and may suitably comprise anchoring or sealing means, such as pipe slips, latching dogs, and other anchoring means for securing members within the'tubing y14 as will be described. It is also understood that the

landing nipples

18 and 19 will include suitable sealing means, such as packings, O-rings and the like to make fluid-tight seals.

Arranged between the spaced apart supporting

means

18 and 19 is a valve means, such as 20, which serves to allow communication from the interior of the tubing 14 to the annulus 16 between the landing nipples 18 and"19. Valve means 20 is suitably a gas lift valve such as described on page 1059 of the Composite Catalog supra. The tubing may also be provided'adjacent the packer 17 with a by-pass means generally indicated by the numeral 21 which may form part of the packing means 17, such as illustrated on page 942 in the Cornpos'ite Catalogue, supra.

The packer 17 may be a packer such as described in 'the U.S.' Patent to Brown 2,719,587, issued October 4, 1955.

Supported and/or secured on the landing nipple 18 in the conception portrayed in Figs. l to 3 is a iirst tubular extension member 22 which serves to lengthen or vary the effective length of the tubing 14. Alternate physical arrangements are illustrated in Figs. 6 to 8 in which the first tubular extension member 22 or a modification thereof such as 40 or 50 may be supported and/or secured on the landing nipple 19. In Fig. 9, tubular extension member 22 is supported and/or secured in landing nipple 18 while in Fig. 10 tubular extension member 40 is supported in landing nipple 19 and extension member 22' is supported in landing nipple 18. In Fig. l1 extension member 50 is supported in landing nipple 18. Figs. 6 to ll differ from Figs. l to in eliminating one of the

valves

20 or 21 and in providing only single valve 20 or 20' for circulation to the annulus. This tubular member 22 projects from the lower open end 15 of the tubing 14 and passes completely through the upper productive horizon defined by the intervals A to E.k The tubular extension member '22 also passes through a second packing means 23 which may be similar to packing means 17. means 23 is provided with a guide means, such as a Aguide nipple 24, which suitably may be the inner mandrel of the packing means 23, having a supporting or seating or seating means 25 arranged therein, or the sealing means may be removably located on the tubing extension to seat in the packing means. The upper end of the guide member has an upwardly aring annular lip 26 which allows the tubular member 22 to be guided into and through the packing member 23 to project into the lower horizon generally indicated by intervals F to H such that its lower open end 27 is adjacent the perforations 28 in the interval H.

The space between the tubular member 22 and the guide nipple 24 is suitably sealed with sealing members, such as O-rings 29, which serve to provide a Huid-tight seal between the

packers

17 and 23. In the instance of Fig. l, flow is had from the hydrocarbon productive interval H, through the passageway defined by the tubular member 22 and up the tubing 14 as indicated by the arrows originating from perforations 28 and also from perforations 30 in the hydrocarbon productive interval A in the zone generally designated as Z enclosed by

packers

17 and 23, the flow being from the perforations 30 up into the annulus 31 between the tubular member 22 and the tubing 14 through the by-pass 21 into the lannulus 16 and then to the earths surface. It is to be noted that the valve 20 in Fig. 1 is in closed position during this operation.

The

perforations

28 and 30 may have been formed prior to starting the operation as shown or may haver been formed by running a gun perforator on a wire line orY conductor cable, as will be illustrated,

In Fig. 2 the production from the intervals A and H is terminated and it is desired to treat the interval, such as H, with a sealing Huid, such as a cement slurry of the type mentioned, water, acid, acid gel, or with fracturing uid to open up or increase the permeability of the formation H. In this particular instance, it will be desired to seal off the perforations 28 by spotting a body of cement slurry as indicated adjacent the perforations 28 to seal same. This may be accomplished by lowering by means of a wire line such as 61 through the tubing 14, a second tubular member generally designated by the numeral 40 and landing or securing same in the landing nipple 19 as illustrated, the wire line 61 being provided with grappling means engaging the upper end of member 44. In this instance, the passageway 21 is closed such as by provision of a covering sleeve 21a and the valve, such as 20, is open to allow ow of fluid, such as cement, down the tubing 14 and the tubular member 40 and vto deposit same as a body 41 adjacent the perforations 28, the iiow being down the tubing 14 and second tubing extension 40 and then upwardly through the annulus 43 into the space 44 between the landing

nipples

18 and 19 and then outwardly into the annulus 16 through valve 20, as illustrated. After the perforations 28 have been sealed, the excess fluid cement, such as 41, in the casing 12 below the packer 23, lmay be removed by reverse circulation from the annulus 16 through the valve 20 into the space 44, down the annulus 43 and then upwardly through the tubular member 40 and through the tubing 14 to the earths surface. This series of operations allows the formations, such as F, G or H, to be suitably treated, as desired, such as with a cement slurry or by acidizing, fracturing, washing, and

' the like.

The packing f With respect to the upper horizon between the

packers

17 and 23, similar operations may be performed for treating the formation A or perforations 30. This is` accomplished by removing the

tubular extension members

22 and 40 by means of a wire line with the valve 20 in the closed positionk and lowering a tubular member, such as 50, through the tubing 14 and landing same on the securing or supporting means 18. This tubular extension member 50. may be of a length less than the length of the

tubular extension members

22 and 40. For example, it may be arranged with its lower end 51 adjacent the perforations 30 or as shown by the dotted lines with vits lower end 51 adjacent any of the other productive intervals, such as B, as may be desired. In any event, the lower productive horizons, such as F to H, are isolated by lowering through the tubing 14 prior to running in the tubing extension member 50 by lowering on a wire line, not shown, an isolating plug 52 and supporting and/or securing same on the supporting means 25. The plug 52 is provided with a fishing neck 53 for lowering and retrieving same and is also provided with a sealing means, such as O-rings 54, for making a fluid-tight seal between guide nipple 24 and the plug 52. It is to be understood that the plug 52 is run in first to isolate the lower horizon from the upper horizon and thereafter the extension member 50 is run in to allow the formation vor strata or intervals A to E to be suitably treated as may be desired. A cement slurry may then be flowed down the tubing 14 and the extension member 50 to spot same adjacent the interval A and to seal the perforations 30 with a filter cake of cement in the' form of buttons or rivet heads 5S as shown. The ow would be as indicated down the tubing and tubular member 50 and up the annulus 31 and thence through the by-pass member 21 into the an. nulus 16. The excess cement slurry, such as 56, may then be circulated out by reversing the flow from the annulus 16 through 'the by-pass 21, down the annulus 31, and then up 'the tubing extension 50 and the tubing 14.

When it'is desired to reperforate in the horizons F toA arn t ,pas

H,'ifitubinggun, such as 60,.may"be lowered onawire line or electricaly conductor cable 61 until it ris adjacent a vertically displaced interval, such as G, and then fired to 'form the perforations, such as 62, to .allow production to be had from the interval, such as G, `the ow being as shown in Fig. l. If, for example, it is desired to reperforate in the upper horizon, a gun perforator or a similar type which may be of a shaped charge or bullet gun type perforator would be lowered on a wire line or conductor cable 61 until it is opposite a hydrocarbon productive interval, such as B, and red to form perforations therein as shown in Fig. 5. Wire line 61 may also be used to move the

tubular members

22 and 40.

It is possible to reperforate in a vertically displaced linterval, such as shown in Figs. 4 and 5, and then to treat this interval with acid or fracturing iluid or wash same with a treating reagent 'or wash liquid.

It isalso contemplated in the practice of the present invention that under some conditions it may not be necessary to reperforate since selected perforations, such as 28 or 30, as-the case may be, may be sealed off and production had from one or more of -the perforations 28 or 3). This situation may apply when there is water and/or gas invasion from the hydrocarbon productive interval and this water and/or gas invasion may be sealed off by sealing oif only a portion of the perforations.

Tlie arrangement of yapparatus with respect to Fig. 6 is identical to Fig. l excepting that 'the tubular member 22 is supported or secured in supporting means 19 rather than supporting means 1S and in the embodiment of Fig. 6 the by-pass means 21 is not provided. Figs. 7 and 8 are similar to Figs. 2 and 3 with omission of by-pass means 21. It is to be noted in Fig. 7 that the tubular member 22 is secured or supported in supporting means 18 while tubular member 40 arranged in tubular member 18 is supported in supporting means 19. In Fig. 8, the tubular member 59 is supported or secured in supporting or securing means 19 rather than in securing means 18 as in Fig. 3. In Figs. 7 and 8, like in Fig. 6, the by-pass means 21 is omitted.

Operations illustrated by Fig. 7 -under identical conditions are the same as those described for Fig. 2 except that in lieu of arranging to blank otf the by-pass means 21, a mechanical rearrangement of tubular extension member 22 must be made to permit seating of tubular extension member 40 in its applicable position at supporting means 19.

In the instance of Fig. 8, the liow path is similar to the ow path for produced hydrocarbons described in Fig. 6, the dierence being that Fig. 8 shows a washing operation.

In Figs. 9 to l1 an arrangement of apparatus is presented which also omits the by-pass means 21 of Figs. 1 to 3. In these embodiments of Figs. 9 to ll, a valve 20 which is similar to valve 20 of Figs. l to 6 is arranged below securing or supporting means 18 and the by-pass means 21 is not provided. Thus, in Fig. 9, the tubular member 22 is supported or secured in securing means 18, like in Fig. l, while in Fig. l0, the tubular member 22 is replaced by a tubular member 22', which is similar to tubular member 22, excepting that at least one or a plurality of ports 72 are provided and the space between packer 17 and tubular member 22 is sealed with sealing means such as 7l) which may suitably be O-rings arranged `in recesses in either the packer 17 or in member 22'. For convenience the member 22 may be provided with recesses 71 to receive O-rings 7l?. Tubular member 22 is secured or'supported in securing means 18 while tubular member ttfissecured or supported in securing means 19. In'Fig. l'l, the tubular member50 is secured or supported in securing means 18 above valve 20.

'The flow'in'l the embodiment ofFig. 9 is similar to that iii-'Fig 1 except withy the valve A'20', ilow, as shown bythe arrows, is then .up tubular extension member"22ifrom perforations 28 in interval .H"Laswell as `up the 'annulus 31 from `perforations 30 4'in interval A thence Athrough valve 20 into annulus `16 to Lthe 'earths surface.

Using the arrangement shown in Fig. 10, to perform the same operations it is necessary only to position tubular extension member 40 at its applicable supporting means 19. The ow is then down-the tubing 14 through tubular member-40, thence up the annulus between itubular member 40 Yand tubular member 22', .through ports 72 and through valve 20"to annulus'16 as shown by the arrows. 1

The flow in the embodiment ofFig. '1l is similar tothat of Fig. 3 with the ilow following the'path lshown bythe arrows down the tubing 14 and tubular member V50,

thence up the. annulus 31'through -valve.2.l) to annulus,

16 and thence to the Veaiths surface. l

In the several embodiments such vas those of `Figs..6zto 1l where the operations andapparatus elements are `similar to Figs. `l to 5.repetition of the description `is not made.

It is to be specifically described with respect to Figs. 1 to 5 may be used in the other embodiments and modes of the present invention.

The valves 20 and v24) referred to in the several gures of the drawing may be sleeve or other type valves, operation of which may be controlled from the wellhead by use of a wire line or by rotating the tubing 14. Examples ofvalves useful in the present invention are shown 1n the Composite Catalog, supra at pages 1059 and 2143. On page 1059 of the Composite Catalog supra, wireline valves and mandrels for accommodating same are described suitable for use in the practice of the presentinvention and .onpage 2143 sleeve type valves are described also suitable for use in the present invention.

It will be seen from the foregoing description taken with the drawing that the present invention is of considerable utility. and importance in well completion loperations where a plurality of hydrocarbon productive intervals is penetrated by a well vbore and production is de-` sired simultaneously or sequentially from both formations utilizing the same well. Particularly, the apparatus of the present invention is of importance because it eliminates the necessity for using heavy duty lifting equipment on a well after it has been completed. The operations of the present invention may all be conducted -witha service truck utilizing wire Ilines and similar suspending, lowering or raising means. In short, the present invention eliminates the necessity for heavyduty equipment and allows workover and service operations to be coriducted at a minimum expense and with minimum capital investment. Also the present invention is advantageous over the prior art in that the plurality of productive horizons and/ or intervals which may be vertically displaced from each other may be worked over and serviced and product removed therefrom with a minimum expenditure of eifort which heretofore was not possible.

The nature and objects of the present invention having been completely described and illustrated, what we wish to claim as new and useful and to secure" by Letters Patent is:

l. For use in working over and servicing a wellhaving a casing arranged therein and provided with a tubing" having its lower open end arranged at a level in said casing above a plurality of productive intervals penetrated by said well, apparatus which comprises first and vsecond spaced apart supporting means arranged in said tubing adjacent the lower end, said second supportingmeans being arranged in said tubing above said first supporting means, a valve means in said tubing arranged below said second spaced apart supporting means, said valve means controlling lluid communication betweenthe tubing and tubing-casing annulus, a'rst tubular extenSQn member understood, of course, that all operationsarranged in said tubing and sealingly anchored in said tubing by said first supporting means for projecting from the open lower end of the tubing for extending the effective length of the tubing, a second tubular extension member arranged in said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufficiently smaller diameter than the diameter of the first supporting means and the first tubular extension member and being arranged Within said first tubular member to provide an annular fluid passageway therewith, first packing means below the valve means and adjacent the lower end of the tubing for closing the lower end ofthe tubing-casing annulus, and second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular member for sealing off a zone in said casing below the first packing means, said second tubular extension member defining a uid passageway independent of said annular fluid passageway and extending from the tubing to a level in said well below said second packing means, said annular fiuid passageway leading from the level in said well below said second packing means into the tubing and thence fluidly communicating with the tubingcasing annulus through said valve means.

2. Apparatus in accordance with claim l in which the valve means in said tubing is arranged between said spaced apart supporting means.

3. Apparatus in accordance with claim l in which the valve means in said tubing is arranged below the first of said spaced apart supporting means, said first tubular member being provided with a port fiuidly communicating the passageway provided by the first and second tubular members with said valve means and sealing means arranged below the port sealing the space between the exterior surface of the first tubular member and the interior surface of the tubing.

4. For use in working over and servicing a well having a casing arranged therein and provided with a tubing having its lower open end arranged at a level in said casing above a plurality of productive intervals penetrated by said well, apparatus which comprises first and second spaced apart supporting means arranged in said tubing adjacent the lower end, said second supporting means being arranged in said tubing above said first supporting means, a valve means in said tubing arranged below said first spaced apart supporting means, said valve means controlling fiuid communication between the tubing and tubing-casing annulus, a first tubular extension member arranged in said tubing and sealingly anchored in said tubing by said first supporting means for projecting from the open lower end of the tubing for extending the effective length of the tubing, said first tubular member being provided with a port, sealing means on the first tubular member sealing the space between the exterior surface of the first tubular member and the interior surface of the tubing, a second tubular extension member arranged in said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufiiciently smaller diameter than the d-iameter of the first supporting means and the first tubular extension member and being arranged within said first tubular member to provide therewith an annular fiuid passageway and being at least co-extensive therewith for the length of the first tubular member, first packing means below the valve means and adjacent the lower end of the tubing for closing the lower end of the tubing-casing annulus, second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular member for sealing off a zone in said casing below the first packing means, said second tubular extension member defining a fiuid passageway independent of the annular fluid passageway and extending from the tubing to a level in said well below said second packing means, said annular fluid passageway leading from the level insaid well below said second packing means into the tubing through said port, and thence fluidly communi.- cating with the tubing-casing annulus through said valve means. v,

5. For use in working over and servicing a well having a casing arranged therein and provided with a tubing having its lower open end arranged at a level in said casing above a plurality of productive intervals penetrated by said well, apparatus which comprises rst and second spaced apart supporting means arranged in said tubing adjacent the lower end, said second supporting means being arranged in said tubing above said first supporting means, a valve means in said tubing arranged below said second spaced apart supporting means, said -valve means controlling fluid communication between the tubing and tubing-casing annulus, a first tubular extension member `arranged in said tubing and sealingly anchored in said tubing by said first supporting means below said second supporting means for projecting from the open lower end of the tubing and for increasing the effective length of the tubing, a second tubular extension member arranged in said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufficiently smaller diameter than the diameter of the first supporting means and the first tubular extension member and being arranged within said first tubular member to provide therewith an annular fiuid passageway and being at least co-extensive therewith for the length of the first tubular member, first packing means below the valve means and adjacent the lower end of the tubing for closing the tubing-casing annulus, second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular extension member for sealing off a zone in said casing below the first packing means, a guide member for said first tubular member carrying said second packing means, said second tubular member defining a fluid passageway independent of the annular fluid passageway and extend-ing from the tubing to a level in said well below said second packing means, said annular passageway leading from the level in said well below said second packing means into the tubing and thence fluidly communicating with the tubing-casing annulus through said valve means.

6. For use in working over and servicing a well having a casing arranged therein and' provided with a tubing having its lower open end arranged `at a level in said casing above a plurality of productive intervals penetrated by said well, apparatus which comprises first and second spaced apart supporting means arranged in said tubing adjacent the lower end, a Valve means in said tubing arranged below said second spaced apart supporting means, said valve means controlling fiuid communication between the tubing and tubing-casing annulus, a tirst tubular extension member removably arranged in said tubing and sealingly anchored in said tubing Yby said first supporting means below said second supporting means for projecting from the open lower end of the tubing for increasing the eective length of the tubing, a second tubular extension member removably arranged in said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufficiently smaller diameter than the diameter of the first supporting means and the first tubular extension member and being arranged within said first tubular member to provide therewith an annular fluid passageway and being at least co-extensive therewith for the length of the first tubular member, first pack-ing means below the valve means and adjacent the lower end of the tubing for closing the lower end of the annulus between the tubing and casing, second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular member for sealing off a zone in said casing below the first packing means, a guide nipple carrying said second packingmeans and extending upwardly therefrom having a diameter greater than the first tubular member, said second tubular member defining a duid passageway independent of the annular fluid passageway and extending from the tubing to a level in said well below said second packing means, said annular uid passageway leading from the level in said well below said second packing means into the tubing and thence liuidly communicating with the tubing-casing annulus through said valve means, said guide nipple providing entry for said first tubular member into said second packing means.

7. For use in working over and servicing a well having a casing arranged therein and provided with a tubing having its lower open end arranged at a level in said casing above a plurality of productive intervals penetrated by said Well, apparatus which comprises first and second spaced apart supporting means arranged in said tubing adjacent the lower end, a valve means in said tubing between said spaced apart supporting means, said valve means controlling fluid communication between the tubing and the tubing-casing annulus, a first tubular extension member removably arranged in said tubing and sealingly anchored in sa1d tubing by said first supporting means below said second supporting means for projecting from the open lower end of the tubing for increasing the effective length of the tubing, a second tubular extension member removably arranged in said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufficiently smaller diameter than the diameter of the first supporting means and the first tubular member and being arranged within said first tubular member to provide therewith an annular fiuid passageway and being at least co-extensive therewith for the length of the first tubular member, first packing means below the valve means and adjacent the lower end of the tubing for closing the lower end of the tubingcasing annulus, second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular member for isolating a zone in said casing below the iirst packing means, a guide nipple carrying said second packing means and extending upwardly therefrom having a diameter greater than the diameter of the first tubular member, said second tubular member defining a fluid passageway independent of the annular fluid passageway and extending from the tubing to a level in said well below said second packing means, said annular uid passageway leading from the level in said well below said second packing means into the tubing and thence fiuidly communicating with the tubing-casing annulus through said valve means, said guide nipple providing entry for said first tubular member into said second packing means.

8. For use'in working over and servicing a well having a casing arranged therein and provided with a tubing having its lower open end arranged at a level in said casing above a plurality of productive intervals penetrated by said well, apparatus which comprises first and second spaced apart supporting means arranged in said tubing adjacent the lower end, a first valve means in saidtubing arranged between said spaced apart supporting means, said first valve means controlling uid communication between the tublng and tubing-casing annulus, said second supporting means being arranged in said tubing above said first supporting means, a first tubular extension member removably arranged in said tubing and sealingly anchored in said tubing by said first supporting means for projecting from the open lower end of the tubing for increasing the effective length of the tubing, a second tubular extension member'removably arrangedin said tubing and sealingly anchored in said tubing by said second supporting means, said second tubular member being of sufficiently smaller diameter than the diameter of the first supporting means and the first tubular extension member and being arranged within said first tubular member to provide therewith an annular fiuid passageway and being at least co-extensive therewith for the length of the first tubular member, iirst packing means below thefvalve means and adjacent the lower end of the tubing for closing the lower end of the tubing-casing annulus, second packing means below the lower end of the tubing having a bore sealingly engaging with the first tubular member for sealing ofi a zone in said casing below the first packing means, said second tubular member providing a liuid passageway independent of the annular fluid passageway from the tubing to below said second packing means, said annular fluid passageway fiuidly cornmunicating through said first valve means with the tubingcasing annulus, and second valve means in said tubing below the first valve means providing uid circulation between said zone and the tubing-casing annulus around said first packing means.

9. Apparatus in .accordance with claim 8 in which the second'valve means providing circulation from the zone to the annulus is arranged in said first packing means.

10. Apparatus in accordance with claim 8 in which the first valve means in said tubing is arranged between said spaced apart supporting means.

11. Apparatus for use in a cased well penetrating a plurality of spaced apart hydrocarbon productive intervals which comprises, in combination, a tubing, inner and outer spaced apart concentric pipes, first and second vertically spaced apart pipe supporting means arranged in said tubing adjacent its lower end, said concentric pipes being removably arranged in said tubing, said outer concentric pipe being sealingly anchored on said first supporting means and said inner cylindrical pipe being sealingly anchored on said second supporting means, said concentric pipes being open on both ends and providing separate continuous uid passageways therethrough, the fiuid passageway in said inner pipe fiuidly communicating and forming with the tubing a flow passage through the tubing and the fluid passageway in said other pipe uidly communicating with the space within the outer pipe between said supporting means and the inner pipe and a flow passage in the casing outside the tubing thru a port located in the tubing in said space, said pipes projecting vco-eirtensively from the lower end of said tubing and isolating said flow passages from each other.

12. Apparatus in accordance with claim 11 in which said outer concentric pipe is provided with means adjacent its lower end for sealing said outer concentric pipe in said well below said tubing.

13. Apparatus in accordance with claim 11 in which means are provided for moving the inner concentric pipevertically relative to the outer concentric pipe.

References Cited in the tile of this patent UNITED STATES PATENTS 1,916,875 Yarbrough July 4, 1933 2,016,919 Church Oct. 8, 1935 2,543,814 Thompson et al Mar. 6, 1951 2,636,563 Rollins Apr. 28, 1953 2,645,291 Voorhees July 14, 1953 2,649,916 Brown Aug. 25, 1953 2,673,614 Miller Mar. 30, 1954 2,674,315 Brown Apr. 6, 1954 2,749,989 Huber June l2, 1956 2,760,578 Tausch Aug. 28, 1956