US2624412A - Hydraulic booster operated well packer - Google Patents

Description

T. M. RAGAN HYDRAULIC BOOSTER OPERATED WELL PACKER Jan. 6, 1953 2 SHEETS-SHEET 1 Filed Feb. 25, 1949 INVENTOR.

ATTORNEYS Patented Jan. 6, 1953 OFFICE gnynammemeos'rsn ommn'rnn W LL PACKER Thomas Ella/gain, Downey, Galifl, 'assignor to "*Baker Oil *Toelsj l nc i-Vcmon, Earl-if -a corpo- Application.EebruaIyQS, laiarserial No. 18,353

reclaim, (019166- 12) in wellbores. I

Certain. typesuofwell packers'remploy slips and packing elements Ithat. are held initially in .re-' xpanded 0 1'1 tracted ..I sition, .and tare the v wardlyi into. engagement with the wall or a :well

casing. ifiuch"outwardexpansionmaylbeaceom-,

instrumentalities, and also by longitudmallyinov-j ing thetubing stringctolwh ich the packenmayisbe attached for running- 150 ,the ,desired locationlin,

the .well casing. The-(slips, maydae anchored-g in retracted position by .oneworwmore shearlscrews;

that areide's gned to vrupture at. a & predetermined pressure l imposed v,on .Vthe' hydraulically -operatd instrumentalities. JIofinsure against prematune and undesired disruption of thescrews. they should .bemade of ample strength. However,,any

increase in diameter-pf the,screwscorthemseof screw .materials having higher shear rstrengths. r.

necessitates vthe imposition ore greaterrunit fluid pressure @on .the hydraulically operated ;ins tr.u.--

' tagesgandmas other objects which may be: made more :clearlyapparent from a consideration'of aiorm inwhich it may be embodied. "This form is shown in the drawings accompanying and "forming part of the present specification. It will nowbe descr'ibedin detail, "for the purposeoi illustrating the general principles of the invention fibut it is to be understood that such detailed description is not to be taken'in a limiting sense,

plish edthroughlthe userofghy'draiilicallyroperated W since the scope of the invention is best defined by the:- appended claims.

"Referring to the drawings:

"Figure "1 is a side elevation of a well packer and setting too'l embodying the present invention 'Figsii2 and 2a are enlarged longitudinal sections throughthe well tool disclosed in Fig. '1, shown with its parts in the relative positions they occupyforrunning the apparatus in a well casing, FigiZaiorming a lower continuation of'FigCZ;

.FigsfiB-andtia are views similar to Figs. 2 and 2 disclosing the apparatus actuated and the packer setfully in the well casingJFig. 3a forming aylowercontinuation of Fig. 3;

Fig. 4is an enlargediragmentary longitudinal mentalities. .Asa result,suchunit pressuresimay- 'section through .a portion of the 'hydraulic be inordinately Thigh. g

Il'tis sometimes notdesiredvtolset amelhpaclger in .lthe .casing thy ,a combination of applying, hydraulicwpressure to theisetting,linstrumentalit ties g'an'di by moving the vtubular;string. .-to ewhi h thegpackerliswattached, longitudinally.inPtheQ-W 11; casing. {At times, ga-acomparativelydarge strain onithefltubing string has, heenrequiredctotset the packer .fully against ethe casing, .which .strain shouldbe avoided. i

r Accordingly, an object of.the presentlinvention is, generally .to improve hydraulicmechanisma'ior setting iwell packers,sorrother Ewell tools in well;

casings.

gAn dther object ref .the invention is .to set lei) operaterawell packer ,or other well tool in a-well' erewith a hi henun fl idapressure than the unit,ijluid pressurein .thetubular string to which 5 thepflibkerortool israttached.

,Aiurtherobjectof vthe.'nventionds to;. provide 5 a hydraulic ,iluid pressure Jaooster iorv,-.settin g as. well-packer. in accasing .or.bore.

jr'st'ill another.objectloitheinvention isrtmprovideianfimproved hydraulic arrangement forsetting a' packer in a Well bore,' in whichsufiicient hydraulic force is available.jforsettingethemacker in packed-elf, con'dition'jini the WeHUcas'in a ainst both upward and downward movement there- Wlt'hin;

booster mechanism, for setting the wellpacker.

(As disclosed in thefdrawings, a well packer Ajis detachably secured ,toasetting tool 10 forming theilower :end of .a tubular string B. running .to

'j theftop of the' well" bore, and by means of which the'packer islowered to the desiredsetting or anchoring point within the well casing C.

The packerA includes a tubular body .1 I having ,angabutment-lz threaded on its lower .end and'a i 5 head [3 at its upperend around-"which the skirt liefsa-cylinder [4a, is. mounted. @A cylinder head 15 .extendslinwardly \from the lower end'of the skirtzandcarries a:suitableiside seal ring IB-in'a raring groove H r slidably engaging "the external surface of the body I l. A suitable side seal ring I8'isalsodisposed ina body-head groove l-9=for slidable -engagement with the interior of the skirt M.

-A set--ef=upper segmented-slips 20 is disposed aroundthe body immediately below the cylinder head I 5. Theseslips are held initially in retracted position lay-shear screws '21 "attaching them to an upper conical expander zz; initially secured to the *body H by "one or more shear screws"23. "The converging surfaces of the upper set of slips'ZO andupper expander 2.2 .are so disposed with respect to one'another as to secure the packer .wagainstzmovementin. an upwardldirection within Ihisinvention possesses many other a'dvanthe casing 'C, or similar well conduit. f ll win outward expansion of the slips 25 into engagement with the casing.

A set of lower segmental slips 24 is provided adjacent the abutment I2. These slips are also secured by shear screws 25 to a lower tapered expander 25 attached initially to the body H by one or more shear screws 2?. The direction of taper on the exterior of the lower expander 26 and the taper on the cooperable surfaces of the lower slips 24 are such as to hold the well packer against movement in a downward direction, following expansion of the slips 24 outwardly to casing engaging position.

A suitable lock is provided between the body H and lower expander 25 to permit upward movement of the body within this expander, but to preclude its downward movement. Such lock may be constituted by a split tapered wedge ring 28 received within the tapered groove 29in the lower expander 25.

A suitable packing, such as a packing sleeve 35 of rubber or similar pliant material, is disposed around the body between the upper and lower expanders El, 25. The ends of the packing sleeve 30 are received within annular pockets formed between the expander skirts 52 and the exterior of the body The setting tool IE] includes a tubular member Ida, the lower portion it?) of which is threaded, as by a left-hand thread 35, into the head IQ of the packer body. This portion ifib has a lower head 35 carrying a suitable side seal 35 for sealing engagement with the inner wall of the body. The head 35 is disposed below body ports 365 positioned between the body and the cylinder head seals l8, [5 to establish communication between the interior of the body II and the annular clearance space 31 between the body head l3 and cylinder head 55. Elongated ports 38, in the form of slots, extend through the tubular portion lfib between its threaded portion 33 and head 34, establishing communication between the interior of the setting tool Iii and elongated annular space 39 between the exterior of the setting tool member Illa and the interior of the body The setting tool member Ilia has a depending tubular section 46 secured to the lower head 34 and terminating in a lower portion 4| projecting from the body I! and abutment I2, for the purpose of holding a back pressure valve in open position. This valve includes a valve head 52 pivoted on the abutment I2 and urged upwardly by a spring 43 into engagement with a valve seat 44 in the abutment. The lower tubing portion 4| can engage the valve head 42 and hold it in open position, as shown in Figs. 2a and 3a.

.A slotted junk pusher and feeler 45 may be secured to the lower end of the lower abutment I2, to insure against premature setting of the well packer during its descent in the well casing. A screen 46 may also be provided across the mouth of the tubing section 4| to prevent undesired substances from entering the setting tool H3.

The setting tool member Ida is provided with a valve seat 47 in the lower head 34 on which a valve ball element 58 is adapted to come to rest, upon being dropped through the tubular string B, in order to prevent downward passage of fluid through the tubular string B and setting tool It] below the setting tool head 34, and allow fluid pressure to be built up in the setting tool member to, the elongated ports 38, and the body ports 36, for the purpose of urging the cylinder [4a downwardly against the upper slips 25. The

cylinder |4a is retained initially in an upward position by one or more shear screws 49 securing its skirt 4 to the body head |3.

The setting tool Ill also includes an upper hydraulic pressure booster portion 50 connected to the lower portion'of the setting tool. Such connection may be efiected by threadedly attaching the lower end of the upper tubular member portion we to the upper end of a lower tubular member lb. The upper portion I50 is, in turn,

threaded into a head or sub 5| secured to the lower end of the tubular running-in string B.

The upper portion 50 of the setting tool It constitutes a hydraulic pressure booster designed to multiply the unit fluid pressure in the tubing string B, and impos such increased unit pressure upon the well packer A, in efiecting its complete anchoring in packed-off condition hydraulically. The hydraulic booster includes an upper fluid motor portion 52. This motor portion consists of an elongate annular cylinder 53 formed by th upper tubular member [0c and a cylindersleeve 54 spaced outwardly from this member. The upper end of the sleeve 54 has a shoulder 55 resting upon a flange 56 projecting from the upper head 5|. The engagement between the shoulder 55 and flange 56 prevents downward movement of the cylinder sleeve 54, whereas upward movement of the sleeve is prevented by one or more lock screws 57 threaded through the upper end of the sleeve and into the head 5|.

The head 5|, in effect, forms the upper or head end of the annular cylinder 53. Fluid may enter the cylinder from within the tubing string B and setting tool member I00 through lateral ports 58 in the head 5| below its flange 56. Such fluid is precluded from passing upwardly between the head 5| and cylinder sleeve 54 by a rubber side seal 59 contained within a ring groove 60 in the flange '56 and engaging the inner wall of the cylinder sleeve.

portion 63 slidable along the exterior of the upper tubular member Inc and spaced inwardly from the cylinder sleeve 54 to provide an annular space 64 therebetween,

piston annulus being slidable along the inner wall of the cylinder sleeve 54. Leakage in both directions between the skirt 63 and upper tubular member disposed in a groove 61 in the skirt and sealingly engaging the exterior of the tubular member lllc. Leakage around the exterior of the composite piston 52 is prevented by a rubber piston ring 68 disposed in a suitable ring groove 69 in the annulus 55 and sealingly engaging the inner wall of the cylinder sleeve 54.

It is apparent that the fluid pressure in the cylinder space 6| between the composite piston 62 and the cylinder head 5| is prevented from leaking downwardly by the ton rings 66, 68. Leakage through the threaded connection between the annulus 65 and skirt 63 may also be prevented by a suitable seal ring 10.

.A piston annulus 65 is threaded, or otherwise. secured, to the upper end of the piston skirt 63, the periphery of the lllc is prevented by a seal ring 66 inner and outer pis-' tends. throughv an intermediate head 12 secured to the: cylinder sleeve 54 by one or more lock pinslz'I3 immediately below bleeder ports: "I4 extending through the cylinder sleeve. The intermediate head I2 has an enlarged portion or flange l5 engaging a shoulder I6 formed. in-the sl'eeve 5d,v such engagement preventing upward movement of the intermediate head lit. with respect to the cylinder sleeve 54. Leakage between the intermediate head 12 and cylinder sleeve is prevented by' a suitable side sealll disposed in.

a..peripheral groove 18 in the head and engaging thednner wall. of the lower portion 5daof the cylindersleeve. Leakage between. the intermediate head .12. and small annular piston or skirt II. is prevented by a side seal I0 disposed within .an

internal-head groove, 80 and slidably engaging the periphery of the skirt II.

The skirt portion is .movable downwardly through the head I2 and within a lower annular cylinder space or chamber 8| formed between the tubular member I00 and the cylinder sleeve portion 54a. Another piston 82 is movable within.

85 and member I00 is prevented by a seal ring B6 disposedwithinan internal piston head groove 81 and slidable along the exterior of the tubular member I00. Similarly, leakage between the sleeve 83 and cylinder 54a is prevented by aseal ring 88 in a sleeve groove 89 slidable along the cylinder portion 54a.

The lower piston 82 has a depending skirt portion 90 projecting from the lower end of the cylinder sleeve 54a and engageable with the upper; end of the lower cylinder sleeve M-disposed around the packer body l I. The lower piston 82 is prevented from rotating with respectto the cylinder sleeve 54 by one or more pins 9 l= secured to the piston and slidable in longitudinally extending slots 92 in the cylinder sleeve.

As pointed out above, the upper piston 65, 63 has an area G. subject to the fluid pressure within the tubing string B that is much greater than the. area. F of the small annular piston II extending through the intermediate head I2. As a result, the unit fluid pressure in the upper cylinder 52 acting over the large annular area G of the upper piston 55, 63 is multiplied several timesby the small piston II acting on liquid filling the chamber 3| below the intermediate head I2. Thus, as an-example, if 1000 p. s. i. is imposed upon the large annular piston 65', 63, and if this piston has three times the area of the'smalle'r annular piston II, the latter will impose a pressure on the liquid in the lower cylinder'space or chamber SI of 3000 p. s. i.

The liquid within the lower chamber 8I is thereby subjected to a much greater unit pressure'than the pressure on the fluid in the tubing string 13, and this greater unit fluid pressure is being imposed on a comparatively large annular;

piston area H provided by the lower piston 82. This fluid is acting over the cross-sectional areaof theupwardly extending piston sleeve 83 and also overthe cross-sectional area of the inwardly di receivable. At the lower end of the upwardly di- 6.. rected piston head 85. area H, as disclosed in the drawings (see-par:-

ticularly Fig. 4) is actually greater than the area:- G of the large, fluid motor piston. 65, 63*.at the 1' upper end of the booster mechanism. Accord-'- ingly, the greatly increased unit imposed on the upper composite piston .65, .63;

Extending the above example, if the lowercrosssectional annular piston area. H is. one-thirdgreater than the area G of the upper piston, and

assuming that-the unit fluid pressure in the lower is three times the unit fluid pressure in the upper cylinder space 6 I, the total 1 force imposed'downwardly on the lower piston-:- 32 will be four times to total hydraulic force cylinder space 81 imposeddownwardly on the upper piston 65, 63; This greatly increased force is, of course, being imparted tothe lower cylinder sleeve Id disposed.

around the packer body I I. Reactively, the force is acting upwardly over the annular area of the upper cylinder head "51 within the cylinder 53, and over the annular area of the intermediate head I2, tending to exert an upward pull on the upper and lower tubular members I00, [0b of the. setting tool, and on the packer body II to which the lower setting tool member" 10b is threadedly attached.

The composite piston E5, 53 forms part of.- afluid motor, whereas the lower annular piston"- portion TI forms part of a fluid pump, which develops'a hydraulic pressure within the cylinder crchamber'SI. This pressure acts upon the piston 82, which actually constitutes a portion of a.

second fluid motor.

The tool is made up in the manner disclosed in Figs. 1, 2 and 2a, except that the ball valve element 48 is omitted. The tool is run down-- wardly through the well casing C on the tubing string B to the'desired point at which the packer A is to be set, and theball valveelement 48 then dropped into the tubing string B from the top'of the well bore, gravitating through the fluid in'the tubing-string until it engages the seat in the: setting tool head 34. Fluid pressure may'then' be imposed on the fluid in the tubing. string'B' and setting tool I0, the ball valve element prevent ing downward passage of the fluid through the setting tool I0 and packer II, and allowing its:

pressure to be increased. Thisfluidjunder pressure in'the tubing string and setting tool is being" imposed on the fluid in the cylinder space 31 in thepacker A, since it can be transmitted thereto'through the body ports 35. It is also being imposed on the fluid in the upper cylinder space SI of the hydraulic booster 50, acting through" the head ports 58.

I3. over the upper booster piston 65, 63, this force beingtransmitted' through the smaller piston TI to the fluid in the lower cylinder space 8|, the pressure of thefluid in this space being increased several times over the pressure in the upper cyl inder space BI' and being imposed downwardly over the lower piston area H. The lower piston 82 exerts a downward forceon the cylinder sleeve 4; I

When

This combined; annular..-

pressure in the. lower chamber. 8| is being imposed over a large; area on the lower piston 82, resulting inka. muchlarger total hydraulic force being directed... downwardly on the lower piston 82 than is being. 1'

the downward force is sufficient to shearthe screws 49 holding the cylinder sleeve I4 to the packer body head l3, and to disrupt the upper slip screws 2 the upper slips are shifted downwardly along the upper conical expander 22 and radially outward into engagement with the easing wall. An increase in the fluid pressure then tends to elevate the booster cylinder 54, setting tool members I01), I00, and the packer body H, inasmuch .as the lower piston 82 and lower cylinder sleeve 14 are prevented from moving downwardly to any further extent by the wedging engagement of the upper slips 2!! with the casing C. When the pressure in the tubing string B has been increased to a sufflcient extent, the shear value of the upper expander screws 23 is exceeded, and these screws are broken, the lower slips 24 and lower expander 26 then being moved upwardly toward the upper expander 22, in order to foreshorten the packing sleeve and expand it outwardly against the wall of the casing.

The fluid pressure in the tubing string B and setting tool It may then be increased to a further extent, eventually exerting an upward force on the hydraulic members and body ll sufficient to disrupt the lower expander screws 2'! and lower slip screws 25, enabling the packer body II to move upwardly to still a further extent, and causing its abutment I2 to shift the lower slips 24 upwardly along the lower expander 26 and radially outward against the casing wall C.

In this manner, the packer A can be anchored in packed-01f condition against movement in the well casing C in both longitudinal directions. The upper slips 20 prevent upward movement of the packer within the well casing, whereas the lower slips 24 prevent downward movement of the packer body I l within the well casing. Any force tending to move the body downwardly is transferred through the tapered lock ring 28 and lower expander 26 to the slips 24, which are anchored firmly against the well casing.

Following complete setting of the well packer A, the tubing string B may be rotated to the left to disconnect the setting tool [9 from the packer A at the left-hand threaded connection 33. The tubing string B and setting tool Ill may then be removed to the top of the well bore. pending portion 4| of the setting tool is elevated,

it moves from engagement with the back pressurevalve head 42, and allows the spring 43 to shift the head-upwardly against the valve seat 43 in the abutment 12.

As the" upper piston 65, 63 is moved downwardly within the cylinder 53, the fluid below the piston head 65 is forced outwardly of the cylinder through the bleeder ports 14; so as to avoid entrapping any fluid below the piston head which I might tend to forestall its movement.

It is evident that the hydraulic booster arrangementenables the well packer A to be set hydraulically with a much greater total force than would be available if the fluid under pressure in the tubing string B were caused to act directly up the well packer A, in effecting its setting. This is due to the multiplication of the unit pressure that the hydraulic booster provides. As a matter of fact, the well packer A could be set by the hydraulic booster setting tool portion 50 in the absence of the body ports 38, or without causing fluid to pass through the body ports 36 at all. Of course, the cylinder sleeve [4, or its equivalent, would still be present in transmitting the downward force of the lower piston 82 and its depending sleeve portion 90 to the upper slips 20.

As the detil The greatly increased hydraulic forceprovided.

been tripped and wedged against the well casing.

C, an upward strain can be taken on the tubing string B, to shear the expander screws 23, 21 and lower slip screws 25, and effect a full packing ofi and anchoring of the well packer in the well casing. If it is not desired to subject the tubing string to a mechanical strain, then the hydraulic force alone can be utilized in completely setting the well packer.

The inventor claims:

1. In well apparatus: a body adapted to be lowered in a well conduit on a tubular string; normally retracted means on said body; means for expanding said normally retracted means against the well conduit, comprising hydraulically operable means engageable with said normally retracted means, a fluid motor responsive to the pressure of fluid in said tubu lar string, a fluid pump operable by said fluid motor for developing a fluid pressure adapted to act on said hydraulically operable means, the

fluid pressure area in said motor over which said fluid pressure in said tubular string is capable of acting being substantially greater than the fluid pressure creating area of the pump.

2. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; and means connected to said body for expanding said normally retracted means against the well conduit, comprising a fluid motor, a fluid pump operable by said motor, and hydraulically operable means responsive to the fluid pressure of said pump and engageable with said normally retracted means, the fluid pressure effective area of said motor being substantially greater than the fluid pressure effective area in said pump, in order that the unit fluid pressure developed by said pump is greater than the unit fluid pressure imposed upon said motor.

3. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; and means connected to said body for expanding said normally retracted means against the well conduit, comprising a fluid motor, a fluid pump operable by said motor to impart pressure to fluid in said pump, and hydraulically operable means responsive to the pressure of the fluid of said pump and engageable with said normally retracted means to urge said normally retracted means against the well conduit.

4. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; a tubular member connected to said body and having a port; hydraulically operable means slidable along said body in response to the pressure of fluid in said member and port; a fluid chamber on said body; means movable in said fluid chamber by said hydraulically operable means to develop a unit fluid pressure in said chamber that is greater than the unit fluid pressure imposed upon said hydraulically operable means; and

means responsive to the pressure of fluid in said :ber on said tubular means; 'means and means responsive *said-phamber for expandingsaid normally retracted means against said well conduit.

- 5. In-well apparatus: tubular means adapted -='to be lowered in awell conduiton a-running-in 4 string; normally retracted means -on said tubular means; said tubular means having a'port; hydraulically operable means slidable along said tubular means in response to the pressure of fluid in said tubular means and port; a fluid chammovable in said fluid chamber by said hydraulically opera ble means to develop a unit fluid pressure therein that is greater than the unit .fluid pressure imposed upon said hydraulically operable means; to the pressure of'fluid in 6. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; tubular means connected to said body and having a port; a cylinder secured to said tubular means and spaced outwardly therefrom to provide an annular cylinder space therebetween communicating with said port; a first piston in said cylinder space which is subject to fluid under pressure in said tubular means and port; means providing a second annular cylinder space around said tubular means; a second piston in said second cylinder space which is shiftable by said first piston, said second piston having a lesser crosssectional area than said first piston; and hydraulically operable means shiftable by the fluid in said second cylinder space to expand said normally retracted means outwardly against the said well conduit.

7. In well apparatus: tubular meanshaving a port and adapted to be lowered in a conduit on a running-in string; normally retracted means on said tubular means; a cylinder secured to said tubular means and spaced outwardly therefrom to provide an annular cylinder space therebetween communicating with said port: a first piston in said cylinder space which is subject to fluid under pressure in said tubular means and port; means providing a second annular cylinder space around said tubular means; a second piston in said second cylinder space which is shiitable by said first piston, said second piston having a lesser cross-sectional area than the first piston; and hydraulically operable means shiftable by the fluid in said second cylinder space to expand said normally retracted means outwardly against said well conduit. 7 v

3. In well apparatus: a body adapted to b lowered in a well conduit on a running-in string; normally retracted means on said body; tubular means connected to said body, and having a port; an elongate cylinder secured to said tunular means spaced outwardly therefrom; a head partially bridging the distance between said cylinder and said tubular means; a first piston movable in said cylinder on one side of said head and subject to the fluid pressure in said tubular means and port; a second piston shiftable by said first piston and slidable along said head; and hydraulically operable means on the other side of said head responsive to the pressure of fluid developed by said second piston for shifting said normally retracted. meansagainst the well conduit.

9. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; tubular means connected to said body and having a port;

'than the cross-sectional area of said second pis- "ton.

-10. Inwell-apparatus aninner member having 'a port;-'an elongatecylindersecured tosaid inner member and spaced outwardly therefrom; a head partially bridging the distance between said cylinder and inner member; a first piston movable in said cylinder to one side of said head and subject of fluid pressure passing through said port; a

second piston shiftable by said first piston and slidable along said head; and hydraulically operable means on the other side of said head responsive to the pressure of fluid developed by said second piston.

11. In well apparatus: an inner tubular member adapted to be lowered in a well conduit on a running-in string and having a port; a cylinder secured to said tubular member and spaced outwardly therefrom to provide an annular cylinder spaced therebetween communicating with said port; a first piston in said cylinder space and subject to fluid under pressure in said tubular member and port; means providing a second annular cylinder space around said tubular member; a second piston in said second cylinder space and shiftable by said first piston, said second piston having a lesser cross-sectional area than said first piston; and hydraulically operable means shiftable by the fluid in said second cylinder space.

12. In well apparatus: a tubular member having a port and adapted to be lowered in a well conduit on a running-in string; hydraulically operable means slidable along said member in response to the pressure of fluid in said member and port; a fluid chamber on said member; means movable in said fluid chamber by said hydraulically operable means to develop a unit fluid pressure therein that is greater than the unit fluid pressure imposed upon said hydraulically operable means; and means in said chamber responsive to the pressure of fluid developed therewithin.

13. In well apparatus: a body adapted to be lowered in a well conduit on a running-in string; normally retracted means on said body; tubular instrumentalities connected to said body and having a port; first cylinder means around said tubular instrumentalities providing an annular cylin- 'der space communicating with said port; first piston means in said cylinder space; one of said first means being subject to fluid under pressure in said tubular instrumentalities and port and shiftable along said tubular instrumentalities; second cylinder means around said tubular instrumentalities providing a second annular cylin- -der space; second piston means in said second cylinder space; one of said second means being shiftable by said one of said first means; and

' hydraulically operable means shiftable by the fluid in said second cylinder space to expand the 14. Well apparatus as defined in claim 13, wherein said one of said second means has a lesser cross-sectional area than said one of said first means.

15. In well apparatus: tubular instrumentalities having a port; first cylinder means around said tubular instrumentalities providing an annular cylinder space communicating with said port; first piston means in said cylinder space; one of said first means being subject tofluid under pressure in said tubular instrumentalities and port and shiftable along said tubular instrumentalities; second cylinder means around said tubular instrumentalities providing a second annular cylinder space; a second piston means in said second cylinder space; one of said second means being shiftable by said one of said first means; and hydraulically operable means shiftable by the fluid in said second cylinder space.

16. Well apparatus as defined in claim 15, wherein said one of said second means has a lesser cross-sectional area than said one of said first means.

' THOMAS M. RAGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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