US2620036A - Self-sealing packer - Google Patents

Description

Dec. 2, 1952 c, K. MORGAN SELF-SEALING PACKER Filed May 19, 1949 IN VEN TOR, CHQLES I6. MPGHA/L ,arma/EV interior of the packer sleeve.

Patented Dec. 2, 1952 SELF-SEALING PACKER Charles K. Morgan, Sierra Madre, Calif., assignor to Lane-Wells Company, Los Angeles, Calif., a

corporation of Delaware Application May 19, 1949, Serial No. 94,096

6 Claims.

This invention relates broadly to packing devices for well boreholes. More particularly it concerns the so-called circulation or by-pass type of packing devices for sealing the annular space between a string of tubing or casing and the surrounding wall or casing, at any desireddistance from the surface or outlet of the bore and which is capable of maintaining such sealing under high differential fluid pressures.

The effective sealing or packing of the annular space in a borehole or well surrounding a centrally disposed pipe, tube or mandrel is conventionally accomplished by lowering the packing device including the packer mandrel, into the well on the lower end of a suitable length or string of tubing or casing to the desired position, while fluid, which may be present in the well, is permitted free, relative iiow or movement along and past the device during the lowering operation. For example, when employing a circulation by-pass type of packer such as that disclosed in Renouf 2,005,955, the fluid present in the borehole is free to by-pass the packer both on the exterior of the unexpanded packing rings and through an annular by-pass passage provided on the Upon arriving at the desired position for setting the packer in the Well, a slip anchorage to the surrounding wall or casing of the well is effected and the mandrel is then lowered within the packer, first causing the circulation valve to close at one end of the fluid by-pass passage within the packer and then upon further lowering, axial force is applied to the annular packing members on the exterior of the packer by means of which they are compressed axially of the borehole and thereby expanded radially into sealing of the by-pass valve and other portions of the packer, tending to force the valve open and reduce the axial compressive force upon the packing members. Accordingly, if the holding pressure is accidentally released or overcome by such differential pressure, even in part, .the secured fluid seal may be broken with resultant leakage and rapid destruction of the packing elements. In any case, the sealing efficiency of the device will be impaired and its repair or replacement may soon be required. Such difficulty is certain to result whenever the opposing pressure in the well balances or exceeds the pressure applied to the packing device to hold it in place.

One object of the invention is, therefore, to overcome the hereinbefore mentioned difficulties and disadvantages prevalent in, and to improve the design and operation of packers, of the socalled circulation or by-pass types.

Another object is to minimize, or to prevent entirely, loosening or impairment of the uid seal effected by the so-called circulation or bypass types of packing devices in wells due to the action of differential fluid or hydrostatic pressure which accumulates or is built up in the wells.

Another object is to provide means automatically to utilize the opposing fluid pressures on the opposite sides of a packing device to assist in maintaining the required fluid seal and tightness of the device in place in the well. l

Other objects, advantages and features of novelty will be evident from the detailed description which follows:

The present invention is characterized by the utilization of the fluid pressure Within the borehole or well beyond the packing device to improve the operation and the efciency of the device. In other words, the force which has heretofore worked against the devices ofthe prior artis made use of by thepresent invention automatically to tighten the packing members rather than to loosen them. To this end, the packing device of the present invention is provided with a second or lower circulation by-pass valve in addition to the usual upper circulation by-pass valve. By this double arrangement of valves,

each valve is shielded by the other from pressure which tends to force it open, and all passages within the packer are thereby sealed against ingress of uid from above as well as from below the packing elements. The opposing fluid pressures are then utilized to apply their combined forces to axially compress and laterally or radially expand the packing elements into sealing engagement with the Ainside of the bore o 'r 'well casing whereby the packer will have a self-sealing or so-called self-energizing effect.'` By this is meant that the packer Willhave atendency to set more firmly within the bore or Iwell` casing 'as the pressure`in either 'directiodacross the packer increases as contrasted with conventional packers in which increased pressure from below usually tends to reduce axial pressure on the packing elements and thus to impair the sealing efficiency of the packer.

In order to illustrate the invention, one concrete embodiment thereof is shown in the accompanying drawings in which:

Figure la is a longitudinal sectional view illustrating the general assembly of the apparatus oi the invention and showing the position of its parts when being lowered into a well casing prior to being set.

Figure 1b is similar to Figure la and is a continuation of the lower end of the latter and shows the remainder of the cage assembly in elevation except for a small part shown in section. Figures la',V and 1b taken together show the entire longitudinal section of the apparatus.

Figure 2 is a longitudinal sectional view similar to Figure 1a but showing the appearance of the apparatus after being set in a well casing.

Figure 3 is a detailed sectional view showing anV alternative form of the upper packer head and by-pass valve portion of the apparatus.

In the drawings, Figure 1a and Figure 2 show, in longitudinal section, part of a borehole or well, lined by a suitable casing I8. Suspended within the casing and from the lower threaded end II of a string of tubing or casing (not shown), is a. packing device which comprises a centrally disposed mandrel I2 along which are mounted, respectively from top to bottom; a

head A for attaching the device to the saidstring of tubing, a packer assembly B, a casing gripping mechanism C and a conventional cage assembly D for actuating and controlling the said casing gripping mechanism.

The casing gripping mechanism C may be of any suitable or desired type. In the form herein illustrated it consists of a conventional conical member or slip cone I3 slidable axially on mandrel I2 and initially, prior to setting as shown inrFigure la, resting upon an upwardly facing stop shoulder I4 formed around the mandrel I2. Slips I6 are slidably mounted in undercut or so-called dovetail grooves I1 formed in the conical portion of member I3 for movement relative along the sloping surface of the cone into wedging or gripping contact with the inside surface of the well casing II). Links or slip reins I9 are pivotally connected at their upper ends `to the lower ends of slips I8 andA at their lower ends to a slip rein ring which is rotatably retained in an annular groove in the cage sleeve member 22 of the cage assembly D which is of the J-slot type (see Figure 1b and the lower end of. Figure 1a). The cage sleeve member 22 has upper and lower cage spring collars 23 and 24 between which extend outwardly bowing cage springs 25 formed to frictionally engage the inside surface of the well casing. Cage springs 25 vare secured at their opposite ends to collars 23 and 24 by suitable bolts or machine screws as indicated in Figure 1b. The cage sleeve member 22 has a so-called J-slot 26 through the wall thereof to receive pin 21 projecting from mandrel I2. The cage assembly D acts in the well known manner as a drag means to assist in the packer setting and releasing operations as will be hereinafter described.

Packer assembly B is mounted on mandrel I2 between head A and conical member I3 of gripping mechanism C. The packer assembly includes a packing-ring sleeve 28 and a lower valve-seat sleeve 38 concentrically surrounding the mandrel I2 and each 1s spaced from the mandrel I2 to form an annular passage 3| and a cavity 44 respectively. The packing-ring sleeve 28 has secured thereto at its upper end an abutment ring member 32 having formed therein an upwardly facing, conical valve seat 33, and a plurality of radially inwardly extending centering lugs 34 which serve to position the packing ring sleeve 28 concentrically about the mandrel I2 and to engage an upwardly facing stop `shoulder 36 formed on mandrel I2.

The head member A is provided with a conical Valve head 31 of resilient material such as rubber, adapted to engage the adjacent conical valve seat 33 when closed, and thereby close off the upper end of the annular by-pass passage 3I. The lower valve seat sleeve 38 is arranged for axial, telescoping movement relative to the packing-ring sleeve 28 through the provision of a slip joint comprising an annular packing retaining ring-nut 39, slidably engaging the exterior of the packing ring sleeve 28 between abutment ring 32 and a bottom stop shoulder 40 at the lower end of sleeve 28. Packing means to bridge the annular clearance space between sleeve 28 and the well casing are provided, by way of example, in the form of a series of coaxial packing ring members or elements 4I of rubber or of other suitable resilient or deformable material, mounted upon the packing-ring sleeve 28, so as substantially to occupy the axial space formed between abutment ring 32 and the retaining nut 39.

The lower valve seat sleeve 38 is formed with an inwardly extending annular flange 43 suitably spaced from the lower end of sleeve 28 normally to provide an annular cavity or chamber 44 which is in communication with the lower end of the annular by-pass passage 3|. Flange 43 has formed therein a downwardly facing, conical, lower valve seat 45 similar in construction and arrangement to, but facing oppositely from. the upper valve seat 33. A lower, conically shaped valve head member 46 is arranged to engage the lower valve seat 45 to seal off annular chamber 44 and the annular by-pass passage 3| from the lower side. Lower valve head 46 is mounted on the top end of a concentric tubular valve head stem 41 slidable longitudinally upon mandrel I2 and yieldably urged upward toward valve seat 45 by suitable means such as a coil spring 48 housed in a counterbore 49 inthe upper end of the slip cone I3. Stem 41 may telescope into counterbore 49 until its outwardly extending annular stop flange or shoulder 2l engages the upper end of the cylindrical, upwardly extending portion 53 of the slip cone I3. The

vvalve stem 41 is prevented from being thrust out of the counterbore 49 and its valve head 46 held out of contact with seat 45, whenever the packing-ring sleeve 28 and lower valve seal sleeve 38 are in their uppermost positions as shown in Figure la. by the Vprovision of a stop pin 5I projecting laterally from valve stem 41 and slidably received in a closed, longitudinal slot 52 formed in cylindrical walls 53 of the counterbore 49 in the top of the slip cone I3. In order to protect valve 46 from excessive compressive forces, the lower valve seat sleeve 38 is provided with a cylindrical housing extension 54 enclosing said lower valve and telescopically slidable over the up-standing cylindrical walls 53 ofthe slip cone counterbore 49. In the lowermost set position of the packing sleeve assembly, as shown in Figure 2, the lower end of the housing extension 54 thereon will engage a stop shoulder 55 on the top of slip cone I3, and its movement upwardly therefrom is limited by stop pin 56 xed in walls 53 and extending laterally into a closed longitudinal slot 51 in the housing eX- tension 54. Additional slots or ports may be provided in housing extension 54 for passage of iiuid through chamber 44 and annular by-pass passage 3| when upper and lower valves 31 and 46 respectively are in open positions as illustrated in Figure 1a. Similarly, additional slots or ports may be provided in walls 53 to insure free movement of fluid into and out of counterbore 49.

Referring now to Figure 3, an alternative construction of the packer head is shown at A in which the by-pass valve head 31 is positioned upon an upper end portion 58 of the mandrel I2 which is of slightly reduced diameter. The valve head is longitudinally slidable a limited distance thereon between the lowermost position as shown in Figure 3 at which the valve head retainer ring member 58 rests upon a shoulder 59 formed around the mandrel at the point of diameter reduction. The valve head member 31 and valve head retainer ring 58 are urged downwardly towards the shoulder 59 by a short helical spring 60 which acts in compression between the top of said valve head 31 and the bottom of an annular recess 62 formed` in the lower end of the body 63.

of the head A. The lower edge of the cylindrical sk irt 64 forming the outer wall of the said annular recess 62 is formed with serrations or notches 65 to permit iluid passage therethrough as hereinafter described.

Thetubing or casing string II is threadedly connected at 56 to the body 63 of head member A in the same manner as hereinbefore described in connection with the head A of Figures la and 1b.

Figures la and 1b together show the entire apparatus and the relative positions of the parts thereof as the apparatus is being run into the casing in a bore of a well preparatory to being set therein. Valves 31 and 46 are initially open and packing elements or rings 4I are unexpanded and out of engagement with casing I8. The settingoperation of the apparatus is conventional and consists in first rotating mandrel I2 in a left-hand directionsuiciently to move pin 21 out of the lateral portion into the longitudinal portion of `J-slot 26 to unhook or release the cage assembly D `for limited longitudinal movement relative to the mandrel I2. Mandrel I2 is thenlowered by the tubing or casing, permitting slip cone I3 to move downward toward cage assembly D which by reason of the irictional engagementof the cage springs 25 with the inside of casing Il] remains stationary, thus causing slips I6 to move outward along the slip cone into wedging engagement with well casing I Il as shown in Figure 2. Further lowering of mandrel I2 next causes the lower valve seat 45 to move downward into sealing con- 'tact with the lower valve head 46 and then the 'upper valve head 31 to move downward into sealing contact with upper valve seat 33, as head A continues to move downward relative to the pack- Aer assembly B. At this point, the by-pass through Ichamber 44 and annular passage 3I between the mandrel I2 and the packing-ring sleeve 28 is thereby closed off. Further lowering of mandrel 1 I2 next forces the lower valve head stem 41 downward into counterbore 49 thereby compress- 'ing spring 48 until the lower end of the housing extension'sleeve 54 contacts thestop shoulder 55 on the top of slip cone I3 as shown in Figure 2.

ments 4I to expand radially against the inside surface of casing I0 and thus complete the sealing of the annular space in the well between the exterior of mandrel I2 and the interior of the casing I0. The parts will then be in the position shown in Figure 2 when completely set.

High differential pressures can now exist orbe created above and below packing elements 4I. If head A is prevented from moving upwardly by either tubing weight or other mechanical restraint or by iluid pressure applied above packing elements 4I in the well annulus, or by any combination of these, high differential pressure may be applied or may be allowed to accumulate on the under side of the packer without any tendency to loosen the setting of the apparatus, since such pressure cannot reach the interior of telescoping sleeves 28 and 38 to act against the lower face of the upper valve head 31 to tend to force it off its seat.

On the contrary, the fluid pressure in the well annulus below the packer will act upon the annular area bounded on the inside by the mandrel I2 and bounded on the outside by the outside diameter of the sleeve 38 tending to force sleeves 38 and 28 into further telescoping relation with respect to one another thereby automatically increasing the longitudinal compressive force applied to the packing elements 4I to increase their sealing force against the casing. Since sleeve 28 is directly abutted by head A through valve 33, 31 which is restrained against upward movement by the string of tubing I I attached thereto, lower valve seat sleeve 38 is the one which will ordinarily move upward in response to pressure in the well annulus below the packer. For this reason the lower valve head 46 and stem 41 is spring pressed to insure its maintaining sealing engagement with valve seat 45 throughout the permissive movement of sleeves 38 and 54 relative to sleeve 28 and the cylindrical walls 53. Slight outward seepage past either of valves 31 or 45 will relieve any fluid pressure which may initially be trapped or which may build up in chamber 44 and annular passage 3| from the piston action or reduction in volume therein due to the telescoping displacement of sleeve 23 relative to sleeve 38. When a spring pressed valve head is provided for the upper valve seat, as shown in Figure 3 as well as for the lower valve seat, pressure in chamber 44 produced by the beforementioned piston action or reduction in volume of chamber 44 and passage 3I will be positively relieved by either of valves 31 or 46 as soon as such pressure exceeds the combined opposing force of either of the valve springs and the respective fluid pressure upon the outer face of such valve.

In setting the packer apparatus when employing the type of packer head shown at A' in Figure 3, weight or downward force may be applied through the tubing string, as before-described, to the mandrel I2, rst moving the valve head 31 into sealing engagement with the valve seat 33 and thereafter compressing helical spring 6U until the lower end of the skirt 64 is brought into abutmentk with 'the adjacent upper end. cf'theA abutmentring member' 32', Thereafter thefo'rce from the tubing string is transmitted positively t0, the mandrel l2.

i Asfbeforedescribedfany excess pressure in the fluid entrapped in vthe' cavity formedwithin .the packer apparatus at 44 and passage 3| may be relievedby the automatic lifting of either valve head 3T' or d5 against the opposingv forces of springs' andd respectively, dependingv upon the direction-of the pressure diierential across the-packerapparatus Thisrelief of pressure will permit. the. telescoping movement between the packer ring sleeve A223 and the valve seat sleeve 38 whichfis necessary for the application of-longitudinal.. compressive force to the packing elements 4l. l

In removing .the apparatus, mandrel l2 is lifted,

rstrelieving thelongitudinal compressive force fromthe packingv rings 4l, fcllowed.bythe opening-.of the upper valve 3l. Upon continued up,- ward `movement of mandrel I2, stop shoulder 36 onimandrel i2 will next contact lugs onV the abutment ring 32. to raise the packing-ring sleeve 28 relative to the valve seat sleevetand thereby loosen packing ring members 4l. As the lifting of the mandrel continues telescoping sleeves.28 and ..38 will reach the limiting relative elongation shown in Figurelaand lower valve seat 45 will then be pulled upward away from valve head 46 when the latter has reached the limit of its upward travel under the force of spring 48 as permitted by stop pin 5l in slot 52.' Finally, stop shoulder i4 on mandrel l2 .will contact the lower end .ofthe slipcone I3 to lift the latter outof the slips I6, whereupon the wedging effect on slips |6will.be relieved and the slips will be retracted from engagement with casing It. The entire apparatus .can then be withdrawn from thev well or moved to be set .in another position in the same well.. From the aboveit will be apparent that the wellpacker apparatus-of the. present invention is so constructed that once the apparatus is set, any increase in fluid pressure on either side of the Vpacker apparatus tends automatically to tighten. and increase the sealing action of the packing elements, insteadof tending to loosen them as has been the eiect prevalent in packer constructions previously employed.

While the invention has been herein shown and described in what is now considered to bea preferred form, it is to be understood that the invention is not limited to the specific details thereof 'but covers all changes, modiications and adaptations within the scope of the lappended claims.

What is claimed is: Y

l. Well packer apparatus comprising in combination: a mandrel for attachment to l.a-fstring of tubing; gripping mechanism longitudinally slidable on said mandrel for releasably engaginga :u'rroundingwell casing; a packing assembly on said mandreladjacent said gripping mechanism comprising a pair. of longitudinally'telescoping sleeves concentrically surrounding` said mandrel .and forming aniannular passage of Variable length between said mandrel and said sleeves, an annular abutment iixed to one of said sleeves, another annular abutment xed to the other of said sleeves, and an annular packing element carried on the exterior of at least one of said sleeves between said abutments; means coupling said gripping mechanism to one of said sleeves and means coupling said mandrel tothe other of said sleeves. for. imparting telescoping movement to said fsleevesfrelative to one another by' movement of .said mandrel'toward said'grip'ping mechanism, and :thereby to. move onecf saidabutmentstoward.'Y the: other, whereby a .longitudinalcoinpressive pressure .may be applied'from-said mandrel through said packing element between said `abutments `to said gripping mechanismzto Vexpandsaid packing. element. radially into sealingengagement with such casing.; initially open valve means-at opposite ends .of said annular passage surrounding said mandrel for controlling flow of iuid'from either direction intolthe. said annular spaceibetween said sleeves andi said. mandrel; whereby said valve means are closed by the said=move ment :ofsaid mandrel toward said casing gripping mechanism and telescopic movement of lsaid sleeves and longitudinal compressive pressure on said packing element between said abutments are automatically increasedv in response to an increase in uidpressure in thewell, exterior to said annular passage. Y

2. Well `packer apparatus comprising: amandrelia packing sleeve surrounding and spaced fromsaid mandrel andforming an annular passage therebetween; casing gripping means longitudinally slidably carried on a lower portion yof said mandrel for releasably gripping the inside of a surrounding casing; an upper outwardly 'extending annular abutment at the top portion of saidpacking sleeve; a lower outwardly extending annular abutment at the lower portion -of said sleeve, said upper and lower abutments being movable longitudinally. with respect to one another; a deformable packing element around said packing sleeve between said upper and lower abutments and adapted to be compressedlongitudinally on said sleevebetween said abutments by movement of said abutments toward one -another; a lower, downwardly facing valve seat on said lower abutment, communicating with the lower. end of said annular passage; an upper, upwardly facing valve seat on said upper abutment, communicating with the upper end of saidannular passage; an upper downwardly facing valve head nxed. on the upper portion of said mandrel above. said upper valve seat; a lower, upwardly facing valve head slidably carried on said mandrel belowsaid lower valve seat; means coupling said lower. valve head to said casing Agripping means permitting longitudinal motion ofl said lower valve head and casing gripping means togetherv on saidmandrel whereby downward motionof said mandrel with respect to saidv casing gripping means'rst seats said lower and upper valve heads on said lower and upper valve seats respectively, thereby closing the lower Aand upper ends, respectively, of said annular passage, and then applies longitudinal compressive force through said valve heads and seats and said abutments to said deformable packing element.

3. Well packer apparatus comprising: a mandrel; a packing sleeve surrounding and spaced from said mandrel and forming anannular passage therebetween; casing gripping `means longitudinally slidably carried on a lower portion of said mandrel for releasably grippingY the inside of 'a surrounding casing; an upper, outwardly extending annular. abutment at the top portion of saidpackingsleeve; a lower, outwardly extendmg annular abutment at the lower portion of saidsleeve, said upper and lower abutments being movable longitudinally with respectto one another; a deformable packing element' around 'said` packing sleevebetween saidupper and lower abutments and adapted to be compressed longitudinally on said sleeve between said abutments by movement of said abutments toward one another, said packing element being thereby expanded radially; a lower downwardly facing valve seat member on said lower abutment, communicating with the lower end of said annular passage; an upper upwardly facing valve seat member on said upper abutment, communicating with the upper end of said annular passage; an upper downwardly facing valve head member on the upper portion of said mandrel above said upper valve seat member; a lower, upwardly facing valve head member slidably carried on said mandrel below said lower valve seat member; means coupling said lower valve head member to said casing gripping means permitting longitudinal motion of said lower valve head member and said casing gripping means together on said mandrel but permitting only limited longitudinal motion of said lower valve head member and said casing gripping means relative to one another on said mandrel; resilient means urging said lower valve head member upward relative to said casing gripping means, whereby downward motion of said mandrel with respect to said casing gripping means first seats said lower and upper valve head members on said lower and upper valve seat members respectively, thereby closing the lower and upper ends, respectively, of said annular passage, and then applies longitudinal compressive force through said valve members to said upper and lower abutments and thence to said deformable packing element on said sleeve between said abutments.

4. Well packer apparatus comprising: a mandrel; a packing sleeve surrounding and spaced from said mandrel and forming an annular passage therebetween; casing gripping means longitudinally slidably carried on a lower portion of said mandrel for releasably gripping the inside of a surrounding casing; an upper, outwardly extending annular abutment at the top portion of said packing sleeve; a lower, outwardly extending annular abutment at the lower portion of said sleeve, said upper and lower abutments being movable longitudinally with respect to one another; a deformable packing element around said packing sleeve between said upper and lower abutments and adapted to be compressed longitudinally on said sleeve between said abutments by movement of said abutments toward one another, said packing element being thereby expanded radially; a lower, downwardly facing valve seat on said lower abutment, communicating with the lower end of said annular passage; an upper, upwardly facing valve seat on said upper abutment, communicating with the upper end of said annular passage; an upper downwardly facing valve head on the upper portion of said mandrel above said upper valve seat; a lower, upwardly facing valve head slidably carried on said mandrel below said lower valve seat; means coupling said lower valve head to said casing gripping means permitting longitudinal motion of said lower valve head and said casing gripping means together on said mandrel but permitting only limited longitudinal motion of said lower valve head and said casing gripping means relative to one another on said mandrel; stop means permitting only limited relative longitudinal motion between said lower valve seat and said casing gripping means and through which longitudinal force may be transmitted from said easing gripping means to said lower abutment at the limit of said longitudinal motion of said lower valve seat and said casing gripping means towards one another, whereby downward motion of said mandrel with respect to said casing gripping means first seats said lower and upper valve heads on said lower and upper valve seats respectively, thereby closing the lower and upper ends, respectively, of said annular passage, and then causes longitudinal compressive force to be applied from said mandrel downward through said upper valve head and valve seat to said upper abutment, and upward from said casing gripping means through said stop means to said lower abutment and thence to said deformable packing element between said abutments.

5. Well packer apparatus comprising: a mandrel; a packing sleeve surrounding and spaced from said mandrel and forming an annular passage therebetween; casing gripping means longitudinally slidably carried on a lower portion of said mandrel for releasably gripping the inside of a surrounding casing; an upper, outwardly extending annular abutment at the top portion of said packing sleeve; a lower, outwardly extending annular abutment at the lower portion of said sleeve, said upper and lower abutments being movable longitudinally with respect to one another; a deformable packing element around said packing sleeve between said upper and. lower abutments and adapted to be compressed longitudinally on said sleeve between said abut-ments by movement of said abutments toward one another, said packing element being thereby expanded radially; a lower, downwardly facing valve seat on said lower abutment, communicating with the lower end of said annular passage; an upper, upwardly facing valve seat on said upper abutment, communicating with the upper end of said annular passage; an upper, downwardly facing valve head slidably carried on the upper portion of said mandrel above said upper valve seat; means coupling said upper valve head to said mandrel for limited longitudinal motion thereon; stop means Xed to said mandrel limiting the downward motion of said mandrel relative to said upper valve seat and through which longitudinal force may be transmitted from said mandrel to said upper abutment at the limit of said longitudinal motion of said stop means and said upper abutment towards one another; a lower, upwardly facing valve head slidably carried on said mandrel below said lower valve seat; means coupling said lower valve head to said casing gripping means permitting longitudinal motion of said lower valve head and said casing gripping means together on said mandrel but permitting only limited longitudinal motion of said lower valve head and said casing g-ripping means relative to one another on said mandrel; `stop means permitting limited relative longitudinal sliding motion between said lower valve seat and said casing gripping means and through which longitudinal force may be transmitted from said casing gripping means to said lower abutment at the limit of said longitudinal motion of said lower valve seat and said casing gripping means towards one another; and resilient means urging lower valve head upward relative to said casing gripping means, whereby downward motion of said mandrel with respect to said casing gripping means rst seats said lower and upper valve heads on said lower and upper valve seats respectively, thereby closing the lower and upper ends, respectively, of said annular passage, and then causes longitudinal compressive force to be applied/from said mandrel downward through `said upper abutment, and upward tromsaid casing gripping means through. .said stop means to saidlower; abutment- .aand thence to. ,said `deformable packing element between saidY abutment-s.

6..1Well npacker apparatus comprising in combination: a mandrel; a head at vone endV of said mandrel for attaching the same to a string of tubing; grippingimeans slidable on'said mandrel, remote from'said headior releasably gripping `the interior of a surrounding Well casing to Van- -chor said Y'device in place therein; packing means mounted on said mandrel Ywith freedom for limited relative 'longitudinal movement thereon intermediate said head and said gripping means, said packing means comprising a first sleeve surrounding'said mandrel and providing on the upper end thereof an :upper valve seat adjacent and facing 'toward said head, a second sleeve surrounding said mandrel in telescoping relation withxsaidrst .named sleeveand providing on the lower end thereof a lower valve seat remote from .and vfacing away from said head; a lower valve headl slidably mounted on said mandrel to engage said lower valve seat and form a nuid seal between the outside of said mandrel and said second sleeve; an upper valve ,head on said man- Vdrel:ltofengage said upper valve seat and form a iuidseal; between the outside of said .mandrel and `said rst sleeve; packing elements surrounding said mandrel and located between elements Voi said sleeves in position to be compressed -longitudinaflly and thereby expanded radially into sealing contact with such well casing by telescoping motion of said sleeves; means Ito seat said valves upon said seats and apply longitudinal :telescoping force to said sleeves after said mandrel is vmoved within said gripping means lsuflicient-ly to cause both Valves to engage their respective valveseats; and means on said gripping means for limiting the longitudinalmovement of said :lower slide-ble valve rela-tive to said packing means.

CHARLES K. MORGAN.

REFERENCES CITED 'Thezfollowing references are of record inthe vfile of this patent:

vUNL'I'E'D STATES PATENTS NumberA Name Date 2,005,955 Renouf June 25, 1935 y461,650 Marler Feb. 15, 1949

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