US2675880A - Perforation washing apparatus - Google Patents

Description

April 20, 1954 A. A. BAKER PERFORATION WASHING APPARATUS 3 vSheets-Sheer, l

Filed June 28, 1948 s sheets-sheet 2 April 20, 1954 vA. A. BAKER PERFORATION WASHING APPARATUS Filed June 28, 1948' IN VEN TOR.

,4A/@0N ,4. 5A/fie April 20, 1954 A. A. BAKER PERFORATION WASHING APPARATUS 5 Sheets-Sheet 3 Filed June 28, 1948 JNVENToR. HARO/v A. A/rE/Q Ja/EMM Patented Apr. 20, 1954 PERORATION WASHING APPARATUS kAaron A. Baker,- Coalinga, Calif., assigner to v Baker OlTools,v Inc., Vernon, Calif., a corpo;-

ration of California Application Jene 2s, 1948, serial No. 35,677 f forming these operationsy with a `single trip'into the conduit string, thereby effecting substantial savings in time and expense. I

Another object of the invention is to provide a washer and well packercapable of being runr in a perforated conduit string on a'singletstring of tubing; the act of disconnecting the tubing string from the wellA packer, after' the latter hasbeen set inthe conduit string,A also renderingl the washer.' eifective for performing its cleaning function. f

A further object of the invention is to provide a perforation washer adapted to be loweredV in the casing or similar conduit string, and having a fluid by-pass that canbe opened or closed in vresponse to rotation of a tubingv string to which the washer is attached.

Y'rz claims. (o1. 16e-2o) Still another object of the invention is to provide a perforation washer having a fluid by-pass vwhich can be selectively opened or closed, and

which is automatically opened upon elevating the washer within a conduit string. f

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of several forms in which it maybe embodied.

Such forms are shown in the drawings accompanying and forming part of the present specifi# cation. These forms will now be described in detail, illustrating thevgeneral principles of the invention; but it is to be understood that such detailed description is not to be taken in a limting sense, since the scope of the invention is best dened by the appended claims. f. Referring to the drawings: Y Figure l is a side elevation of the perforation washer and well packer apparatus'disposed in a perforated string of casing;

Figs. 2 and 2a are longitudinal sections, partly in elevation, of the perforation .washer-and circulationV valve, with their parts disposedv in one relative position, Fig. 2a lforming a `lower continuation of Fig.2;

Figs. 3V and 3a form a combined longitudinal sectional andy elevational view of the apparatus,

with the parts in position'for washingthe casing perforations, Fig.3a forming, a lower continua- .tionofFig.3; f Y.,

Figs. 4, 5 and 6 are cross-sections taken-along the lines 4-4, 5 5 and 6--6', respectively, of Fig. 2; and Y Fig. 7 is a longitudinal section of a modined form of by-pass valve mechanism. t Y

-The `apparatus disclosed in the drawings is adapted to be Arunin awell casing A, or similar conduit string, on afstring B of tubing, drill pipe, or the like, extending to the top of the welLbore. The apparatus includes fa perforation-washer C at its'lupper portion in the form of a well packer. an intermediate circulation valve or joint D attached to the lower end of the washer and a well packer E secured to the lowerfend of the circulationfjoint. f L l A It is desired to anchorthe well packer E in packed-off condition 'within-the well casing A below-Y its perforations I0,` and then wash the perforations by pumpngwashing uid down the tubing string B for 'outward passage through the perforations I0 'below the washer C to the ex'- terior of the casing string, the washing fluid then passing back into the-easing string throughy the perforations above the -washer- C, for upward iiowing to the top of the well bore.-

The well packerlmay be of lany.'suitablevform and. type, the one disclosed in the drawing' being specifically described in United States Patent No. 2,121,051.v Essentially, `it c'onsists'of, a tubular Abody V-I |-having" upper and lower expanders l2, I3 thereon; andi an intervening y rubber packing sleeve I4. The upper expander cooperates with 'upper segmental slips" I5,to prevent upward movement of the packer inY the well casing; while the lowerv expander' cooperates-with lower segmental slips IG, 5to prevent downward'movenent of the-V` packer inthe casing, The intervening Vpacking sleeve Mis adapted to be'foreshortened and expanded outwardly-into leak-proof engagement withthefcasing wall. AFurther details of the packer E arefun'necessary toan understanding ofthe `-present invention, and "maybe found in thepatent above'referred to; When set inthe vcasing as a bridging plug, the central passage through thepa-cker bodyis 'pluggedg i VThe circulation valve or joint D is' attached to the packer body lli through .the agency ofiasub .I1 havinga left hand male thread 1I 8V mating with a companion thread' (not shown) in-the packer body I I, in a known manner. r,Thesub is secured dto a lowerfc112111ation joint tubular mandrel:l I9 itelescopedwithin an"f iuterbarrclv 2 0. Thebarrel has a lower.V 'cylindrcalfvalva Seat. 2-,i .se.11.rged to it. in which: miniem@ yLSnlined .'stonmemher {22A/1s threaded; ,This magenta-,is@wearable with. 'e heslpi. 95.1 en@ .gf .tra mandrel I9, the head carrying a suitable seal ring 24 adapted to engage within the seat 2I and prevent passage of fluid between the interior and exterior of the circulation valve through the annular space between the mandrel I9 and splined stop member 22.

The mandrel has longitudinally extending splines 25 cooper-able with internal splines 26 on the stop member, in order to transmit the rotation of the barrel 20 to the mandrel I9, in effecting unscrewing of the sub I8 from the packer body I I after the packer has been set in the well casing.

The upper end of the circulation-valve barrel 20 is threadedly, or otherwise attached, to the lower end of a tubular inner body or mandrel 21 forming part of the perforation washer or well packer C. The upper end of this mandrel `21 is attached to the lower end of the running-in string B, which extends to the top'of the well bore. mandrel has a tubular outer body Y28 threadedly attached to its upper portion, and held thereon by a suitable lock nut 29 threaded on the inner body 21 and clamped against the outer body.

The bodies are spaced from each other to vform an annular by-pass passage 39 having ports 3| opening outwardly through the outer body 23.

The well packer C includes a downwardly vfacing rubber `packing 32, or swab cup, which is mounted on the outer body 28 below its ports 3 I and is adapted to slidably seal with the wall or the well casing A. The base 33 of the packing engages the end of a flared sleeve 34 secured to the lower end of the outer body 28 by suitable welding material 35. The sleeve 34 extends downwardly in spaced relation with respect to a tapered flange 36 on the inner mandrel 21, to form a continuation of the by-pass passage 30. The spaced relation between the flared sleeve 34 and flange 36 may be maintained by welding a spider 31, or spaced lugs, between the two elements. The upper end of the packing cup 32 engages a thimble 38 abutting a clamp nut 3-9 threaded on the outer body 28, which is prevented from loosening by a suitable lock nut 40.

It is apparent that the by-pass 30 between the tion. The companion valve structure 42 includes an annular valve head or ring 43 secured to a depending sleeve 44 by headless s crews 45, and having an annular valve sealing element 46 attached to its upper end by screws 41. This an- .nular valve sealing element is engageable with the valve seat 4I to close the by-pass passage.

Movement of the valve head 43 and its seal 46 toward the valve seat 4I is determined by a drag device 48, and is responsive to rotation of the tubing string B and-valve body..21. The upper end of the drag device consists vof aco1lar r49 slidable on the dependingsleeve 44 and adapted `to rest upon a lower Vsleeve flange 50. y Theupper ends of circumferentially spaced, :outwardly bowed springs 5I lare )secured to the fcollar by an .encompassing ring 52 and screws V53 .passing through the ring andthreaded into the collar. 'The bowed springs drag -frictionally along`V the wall of the casing string A, with their lowerends secured toa rlower internally threaded'collaril The iii)

by means of an encompassing ring 55 and screws 56. This lower sleeve is in threaded engagement with an inner sleeve 51 disposed on the mandrel 21 and prevented from moving longitudinally thereof by upper and lower snap rings 56 engaging its upper and lower ends and received within external grooves 59 in the mandrel. This sleeve is non-rotatably held on the mandrel by a key 60 in the mandrel extending into a keyway 6I in the sleeve.

The valve head 43 is urged toward its companion seat 4I Vby a helical spring 52 disposed around the mandrel, with its upper1 end engaging the dependingsleeve 44 and with its lower end bearing upon a spring seat or spacer sleeve 63 resting upon the inner threaded sleeve 51. The spring is compressed and is initially prevented from moving the head 43 into engagement with the valve seat 4l by virtue of the engagement of the sleeve flange 50 with the lower end of the upper drag collar 49. The drag collar i9 oc-y cupies an initial lower position because of the fact that the lower drag collar 54 is initially assembled so as to be disposed on the lower threaded portion of the inner sleeve 51. It is to be noted, however, that theA valve head 43, although its upward movementis limited by engagement of the`sleeve flange 58 with the upper collar 49, can move downwardly with respect to the latter member, because of the clearance space existing between the lower end of the head 43 and the upper end of the collar 49. y

The apparatus is lowered in the perforated well casing A on the end of the tubular string B,` with the lower drag collar 54 mounted on the lower end of the inner sleeve 51, which causes the upper collar 49 to hold the valve in open position, as disclosed in Fig. 2. The circulation joint D is attached to the washer mandrel 21, which is, in turn, secured to the well packer E through the agency of the left hand threaded tubular sub I1. The slips I5, I6 and packing sleeve I4 of the packer are in retracted positions.

The apparatus is lowered through the well casing A until the packer E is ldisposed below the perforated portion of thecasing string, whereupon the slips I5 and packing I6 are expanded .outwardly against the casing in a known manner, described in the. aforesaid United States patent, to form a bridge or plug in the well casing preventing downward passage of fluid. During llowering movement of the apparatus through the well casing, its downward passage is not prevented by any fluid therein, since such iluid can move around the rubber packing cup 32 by owing through the open by-pass 36.

After the packer is anchored in the casing, the tubing string B is rotated to the right to effect Idisconnection of the left hand threaded sub Il from the packer body I I. The rotation of the tubing string B is transmitted to the sub il through the washer mandrel or body 21, outer circulation valve barrel 29, cooperable splines 26, 25 and mandrel I9, the telescopic circulation valve allowing the threaded disconnection to occur readily vsince the unthreading action merely elevates the mandrel I'Gwithin the barrel without any of the load of the running-in string or perforation washer being imposed on the left hand threads I8.

During this 'rotation of the washer mandrel 21in electing disconnection oi' the sub Il from the packerbody Il, the inner threaded sleeve 51 isalso rotated within'the lower collar 54, the latter being prevented from rotating the irictionall engagement .of the outwardly Ubowed springs 5l with the casing wall. Sincer vthe threaded connection between the inner sleeve 51 andthe lower collar 54 is a right hand thread, the, rotation of the mandrel 21 to the right, or clockwise, will effect relative upward threading of the lower collar 54 on the inner sleeve 51, and

will correspondingly shift the upper drag collar` 49.toward the valve seat 4l, allowing the spring` 62 to engage the valve head seal 46 with the seat 4I and close the by-pass 3U against upward flow of fluid (Fig. 3). The motion just referred to is a relative one. As a matter of fact, the drag device 48 and its collars 49, 54 may remain stationary, the rotating of the tubular mandrel 21 allowing the tubing string B and inner and outer bodies 21, 28* to be lowereda suflcient distance relative to the drag device 48 to move the valve seat 4l into engagement with the vvalve head seal 45. The threaded connection between the inner sleeve 51 and lower collar 54 may be considered as a form of axial cam effecting axial movement of the collar 54 upon rotation of the sleeve 51. i g Withl the passage 3U closed against vupward ow of Huid, the casing perforations I0 can now be washed. The tubing string B is lowered to locate the swab cup 32 immediately above a lowermost perforatedcasing region, and washing fluid pumped down thetubing string for outward passage through the circulation valve D or left hand sub lI1, this fluid then flowing through the perforated casing portions below the packing cup into the annulus around the casing string. Any particles that may have been plugging the casing perforations I0, or any loose materials behind the casing string are flushed upwardly along the exterior of the casing to a point above the packing cup, where they `can re-enter the casing through the perforations IU and flow upwardly through the tubing-casing annulus to the top of the well bore. Sufcient pressure vcan be applied to the fluid to insure thorough cleaning of the perforations l0. It is .to be noted that the packing cup 32 prevents flow of fluid between the outer body 28 and casing A; while the upwardly. seating valve member 43l closes the bypass 30 against ,upward passage of 4fluid.V The only course that the washing liquid can ,pursue is the one described above, namely, out through the perforations Il) below the packing 32, up along the exterior of ythe casing string, and back into the casing through the perforations I0 above the packing cup 32.

. After a lower section of perforations is cleaned,

the tool may be elevated and the next adjacent group of perforations cleaned in the foregoing manner until the entire perforated casing section has been thoroughly washed. The washer is now removed from the well bore, its elevation :being unhampered by the liquid in the well casing since such liquid can flow downwardly through the bypass 30, unseating Ythe valve 43y against the Vvaction of the spring 62, some of the liquid also flowing downwardly around the exterior of the packing cup 32. It is evident that' the by-pass valve is in the nature ofV acheck valve, or one-way valve, allowing relative downward passage of iluid through the by-pass merely as an incident of elevating the tubingv string B and without the necessity for otherwise manipulating the tubing string to effect opening or closing of the by-pass 30. A modif-led form ofV by-pass valve-.device is shown. inFig. 7, in which itis kdesired `to insure against plugging of the passage 30 by detritus, rubber particles, or otherr foreign substances in the well bore.

In this form of the invention, av spider, having an inner sleeve portion 36a mounted on the inner body 21 and spaced lugs 31a engaging the flared sleeve 34a, is welded to the inner body 21 bysuitable. welding material 10. The lower ends of the spaced sleeves 36a, 34a are rounded or beveled to. form lconcentric valveA -seats 41a adapted to be engaged by an annular at rubber valve sealing element 46a secured to the valve head 43a by cap screws 41 and washers 1I. The space 12 between the valve head seal 46a and seats 41a is screened by a cylindrical perforated member 13 attached to the valve head 43a in any suitable manner, as by the screws 45 securing the valve head to the depending sleeve 44.y This `screen extends upwardly for engagement with the periphery 14 of the flared sleeve 34a, the engagement being maintained at all times.

Itis evident that any fluid passing upwardly` through the by-pass must flow through the screen 113, whose perforations 15 are small enough to prevent large size particles from passing into the by-pass and possibly plug it. In allwother respects, the valvemechanism functions in the same manner as the other form of the device.

The `inventor claims:v f 1. In apparatus of the character described: a well packer adapted to be set in a conduit string positioned in a well bore; a perforation washer detachably secured to said packer, said washer having a conduit `engaging packing element and a by-pass around said element, said by-pass having a valve seat; said washer having valve means engageable with said seat; means engageable with said valve meansv and disposed normally in a position holding it off said seat; and means operatively connected to said holding means and washer to hold said holding means in said position and movable by said washer, upon movement of said washer to disconnect said washer from said packer, to shift said holding ymeans to another position allowing said valve means to engage said seat.

l 2. In apparatus of thecharacter described: a first wellpacker adapted to be set in a conduit string positionedV ina well bore; a second well packer above salid'flrst packer adapted to be lowered in said conduit string on a tubular runningin string for sealing engagement with the conduit string; means `detachably connecting said second packer to said first packer; said second packer .having a packing element engageable with said conduit string and a by-pass around said packing element, said by-pass having a valve seat;` valve means movable to and from said seat to control fluid flow through said by-.pass; and means operatively connected to said valve means to hold said valve means in a` position off its seat .and responsive to rotation of said tubular string in disconnecting said second packer from said rst packer for eiecting shifting of said valve .means to another position Vin engagement with said seat to'close said Icy-pass'.

- 3.A In apparatus of the character described: a first well packer adapted to be set in a conduit string positioned in a well bore; a secondfwell packer above said rst packer adapted to be lowered in said conduit string on a tubular running-in string for sealing engagement with the conduit string; means detachably connecting said second packer to said first packer, rotation of said second YPackerrelativeto Said rS Packer,

disconnecting it from said first packer; saidasecond' packer having a packing element engageable. with said conduit string and a by-pass aroundI said packing element, said by-pass having a valve seat; valve means movableto and from saidV seat to control fluid ow through said by-pass; and means operatively connected to said valve means to hold said valve means in a position off its seat and responsive to rotation of said tubular string and second packer for effecting longitudinal shifting of said valve means to another position in. engagement with said seat to close said ley-pass.

4. In apparatus of the character described: aA rst well packer ,adapted to be set in a conduit string positioned in a well bore; a second well packer above said iirst packer adapted to be lowered in said conduit string on a tubular running-in string for sealing engagement with the conduit string; means detachably connecting said second` packer to said rst packer, rotation of said second packer relative to said rst packer disconnecting said second packer from said iirst packer; said second packer having a packing element engageable with said conduit string and ,a by-pass around said packing element, said bypass having a valve seat; valve means movable to and from said seat to control fluid now through said by-pass; conduit engaging meansengageable with said valve means and normally disposed in a position holding said valve means in open position; and means operatively connected to said conduit engaging means and second packer to hold said conduit engaging means in said position and for shifting said conduit engaging means to another position permitting movement of said valve means into engagement with said seat to close said by-pass upon rotation oi said second packer in eiecting disconnection of said second packer from said iirst packer.

', In apparatus of the character-described: an

outer tubular member adapted to bepositioned in a well conduit string; a packing on said member for sealing with the well conduit; an inner tubular member spaced from said outer member to form a by-pass around said packing, said bypass having a valve seat; a valve member on said inner member movable upwardly into engagement with said seat to close said by-pass; means engageable with said conduit string and valve member and normally disposed in .a position holding said valve member in open position with respect to said seat; and means providing an axial cam interconnection between said holding means and inner tubular member to hold said holding means in said position and to enablev rotation of said inner tubular member relative tosaid holding means to shift said holding means relatively longitudinally along said inner tubular member to another position permitting said valve. member to engage said seat and close said bypass.

6. In apparatus of the character described: tubular means adapted for connection to a tubular string for running said tubular means in a well conduit; a packing on .said tubular means for sealing with the well conduit; said tubular means having a bly-pass extending around said packing, said by-pass having a valve seat; valve means on said tubular means for controlling fluid ilow through said by-pass; means engageable With said valve means and normally disposed. in a position holding said valve means in open position; and means providing an axial camr interconnection between said holdingmeans and tubular means to hold saidv holding meansin saidposition and to enable rotation of said tubular means relative to said holding means to produce shifting of said holding means relatively longitudinally along said tubular means to. another position allowing said valvemeans to engage said seat and close said bypass.

7. In apparatus of the character described: tubular means .adapted for connection to a tubular string for running said tubular means in a well conduit; a packing on said tubular means for sealing with the well conduit; said tubular means having a by-pass extending around said packing, said by-pass having a valve seat; a valve member slidable along said tubrular means for controlling fluid llow through said by-pass; means engageable with said well conduit and valve member and normally disposed in a position holding said valve member in open position with respect to said seat; and means providing an axial cam interconnectionbetween said holding means and tubular means to hold said holding means in said position and to enable rotation of said tubular means relative to said holding means to produce shifting of said holding means relatively longitudinally along said tubular means to another position allowing said valve member to engage said seat and close said by-pass.

8. In apparatus of the character described: tubular means adapted for connection to a tubular string for running said tubular means in a well conduit; a packing on said tubular means for sealing with the Well conduit; said tubular means having a by-pass extending around said packing, said by-pass having a valve seat; a valve member movable upwardly along said tubular means into engagement with said seat to close said by-pass; a drag device engageable with said valve member and normally disposed in a position holding it in a position opening said by-pass; and means providing an axial cam interconnection between said drag device and tubular means to hold said drag device in said position and to enable rotation of said tubular means relative to said drag device to produce shifting of said drag device relatively longitudinally along saiclA tubular means to another position allowing said valve member to engage said seat and close said by-pass.

9. In apparatus of the character described: tubular means adapted for connection to a tubular string for running said tubular means in a well conduit; a packing on said tubular means for sealing with the well conduit; said tubular means having a -by-pass extending around said packing, said by-pass. having a valve seat; a valve member slidable along said tubular means; spring means around said tubular means for urging said valve member upwardly into engagement with said valve seat to close said by-pass; means engageable with said valve member and normally disposed in a position holding said valve member in open position with respect to said valve seat; and coengaging threaded means on said tubular means and holding means for relai, tively shifting said holding means longitudinally of Said tubular means to another position upon rotation of said tubular means relative to said holding means, thereby allowing said spring means to shift said Valve member into engagement with said valve seat.

10. In apparatus ofV the character described: tubular means adapt'ediorv connection to a tubular string for running said tubular means in a Well conduit; a packingon said tubular means for sealing withthe well conduit; said tubular means having aby-pass extending around said packing, said by-pass having a valve seat; a valve member slidable along said tubular means; spring means around said tubular means for urging said valve member upwardly into engagement with said valve seat to close said by-pass; means engageable with said valve member and conduit string and normally disposed in a position holding said valve member in open position; and means providing an axial cam interconnection between said holding means and tubular means to hold said holding means in said position and to enable rotation of said tubular meansrelative to said holding means to shift said holding means relatively longitudinally along said tubular means to another position allowing movement of said valve member intoengagement with said seat to close said by-pass. Y

ll. In apparatus of the character described: tubular means adapted connection to a tubular string for running said tubular means in la well conduit; a packing on said tubular means for .sealing with the well conduit; said tubular means having a by-pass extending around said packing, said by-pass having a valve seat; a valve member slidable along said tubular means; spring means around said tubular means for urging said valve member upwardly into engagement with said seat to close said by-pass; means engageable with said valve member and conduit string for holding said valve member off said seat and in open position; and coengaging threaded means on said tubular means and holding means for relatively shifting said holding means longitudinally to ineective position upon rotation of said tubular means, thereby allowing said spring means to shift said valve member into engagement with said seat to close said by-pass.

l2. In apparatus of the character described: tubular means adapted for connection to a tubular running-in string; a packing on said tubular means for sealing with the well conduit; said tubular means having a by-pass extending around said packing, said rIcy-pass having a valve seat; a valve member slidable along said tubular means; spring means around said tubular means for urging said valve member upwardly into engagement with said seat to close said by-pass; a drag device including an upper collar engageable with said valve member for holding said valve member on' its seat and in open position, a lower drag collar and outwardly bowed springs connected to said collars and frictionally engageable with said well conduit, said lower drag collar being internally threaded; and a member fixed to rotate with said tubular means and threadedly engaging said lower drag collar, whereby rotation of said tubular string will, effect relative shifting of said drag device longitudinally of said tubular means to render said upper drag collar ineffective to hold said upper valve member off its seat.

13. In apparatus of the character described: a first well packer adapted to be set in a conduit string positioned in a well bore; a second well packer above said first packer adapted to be lowered in said conduit Y string on a tubular running-in string for sealing engagement with the conduit string; means providing a detachable left-hand threaded connection between said packers; said second packer having a packing element engageable with said conduit string and a by-pass around said packing element, said bypass having a valve seat; valve means movable to and from said seat to control iluid flow through said by-pass; means engageable with said valve means and normally disposed in a position holding said valve means in open position with respect to said seat; and means engaging said holding means to hold said holding means in said position and responsive to rotation of said tubular string in unthreading said second packer from said first packer for shifting said holding means to another position allowing said valve means to engage said seat and close said by-pass.

14. In apparatus of the character described: a iirst well packer adapted to be set in a conduit string positioned in a well bore; a second well packer above said rst packer adapted to be lowered in said conduit string on a tubular runningin string for sealing engagement with the conduit string; means detachably connecting said second packer to said rst packer; said second packer having a packing element engageable with said conduit string and a by-pass around said packing element, said by-pass having a valve seat; a valve member on said second packer movable upwardly into engagement with said seat to close said by-pass; means engageable with said conduit string and valve member and normally disposed in a position holding said valve member in a lower and open position with respect to said seat; and means engaging said holding means to hold said holding means in said position and responsive to rotation of said tubular string in disconnecting said second packer from said iirst packer for shifting said holding means to another position allowing said valve means to move upwardly into engagement with said seat to close said bypass.

l5. In apparatus of the character described; a well packer adapted to be set in a conduit string positioned in a well bore; a perforation washer detachably secured to said packer, said washer having a, conduit engaging packing element and a by-pass around said packing element, said bypass having a valve seat; said washer having valve means movable longitudinally into and out of engagement with said seat; means engageable with said valve means and disposed normally in a position holding it off said seat; and means operatively connected to said holding means and washer to hold said holding means in said position and movable longitudinally by said washer, upon movement of said washer to disconnect said washer from said packer, to shift said holding means longitudinally to another position allowing said valve means to move longitudinally into engagement with said seat.

16. In apparatus of the character described: a rst well packer adapted to be set in a conduit string positioned in a well bore; a second well packer above said iirst packer adapted to be lowered in said conduit string on a tubular running-in string for sealing engagement with the conduit string; means detachably connecting said second packer to said first packer, rotation of said second packer relative to said iirst packer disconnecting it from said iirst packer; said second packer having a packing element engageable with said conduit and a by-pass around said packing element, said by-pass having a valve seat; valve means movable axially to and from said seat to control fluid flow through said bypass; conduit engaging means engageable with said valve means and normally disposed in a position holding said valve means longitudinally spaced from said seat to maintain said by-pass in open condition; and means operatively con- 1 l nected to said conduit engaging* means and second packer to hold said conduit engaging means in said position and for shifting said conduit engaging means axially to another position permitting axial movement of said valvevmeans into engagement with said seat upon rotation of said second packer in effecting disconnection of said second packer from said rst packer.

17. In apparatus of the character described: a first Well packer adapted to be set in a conduit string positioned in a Well bore; a second well packer above said iirst packer adapted to be lowered in said conduit string on a tubular runningin string for sealing engagement with the conduit string; means providing a detachable left-hand threaded connection between said packers; said second packer having a packing element engage# able with said conduit string and a by-pass around said packing element, said by-passl having a valve seat; valve means movable lengthwise of the axis of said seat and to and from said seat to control fluid flow through said by-pass; means engageable with said valve means for holding said valve means axially,r inopenY positionwith respect tor said seat; and means engaging said holding means to hold said holdingrneans in a position holding saidl valve means openV and-responsive to rotation of the tubular running-in string in unthreading said second packer from said first packer for shifting said holding means-axially to another position allowing said valve means to move axially into engagement with said seat to close said bypass.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,992,933 Baker etal. Mar. 5, 1935 2,048,136 OConnor July 21, 1936 2,275,938 Baker Mar. 10, 1942 2,326,940 Granger Aug. 17, 1943 2,390,112 McGaiey Dec. 4, 1945 2,402,886" Granger June 25, 1946 2,404,876 Granger July 30, 1946 2,577,068 Baker Dec. 4, 1951

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