US2519116A - Deformable packer - Google Patents

Description

' Aug. 15, 195o W- S. CRAKE DEFORMABLE PACKER Filed Dec. 28, 1948 WFred 5. CmKe Patented Aug.y 15, 1950 v' Wilfred S.Crake, HoustomTex., assignor to Shell f Development Company, San Francisco, Calif.,

a corporation of Delaware Applieannnember 2s, 194s, seria1No.67,7o7

. This invention relates `to new and'useiul` improvements'in packing elements and pertains moreV particularly to casing-packersv for well producing installations as, 4for example.pumping systems that are commonly used. inoilwells.

I In an oil well linedwith va casingzand having Aan inner string of pipeor-tubing extendingwithin said well casing to removethe well fluid therefrom, it is often desirable to' pack yor seal off the annular space between the tubing string and the outer casing. Many oiland gas nelds'fhave more than one' producing zone andvoil orgasmay'be obtained from two zones simultaneously by ern- `ploying asingle well comprising two concentric production strings. A suitable packeris carried on' the inner string of pipe or tubing' and vis `ar, .ranged to sealingly engage the well casing so that production from the lower `zone is produced through the inner tubingy string fwhile the pro-` .duction from the upper-zone flows `through the j4Qc1afims. (cl. 16e-1o) annular space between the well casing and the inner tubing string. Packers that. are,` generally rused in an installation `of the above-described type tov seal the annular'splace between the casing `and the tubing `string :are normally made` of a flexible or resilient materialandi are set'by gmanipulation of the tubingfstring. f I,

AAn object of this inventiori is to` providey a simple, eicient and lcommercially practical method for permanently packingfoff the annular f n `.space in awell between the welll casing andan inner production tubing; l, positioned therein whereby two spacedfor 'separate zones `may be simultaneously produced through said casing and said tubing.` l

Another object of provide a permanently set casing-packer adapted to be carried by atubing s'tringlinserted in a well y casing and explosively [expanded against'the e `inner wall of the well casing;` whereby a uidl tight joint or sealis formed between-said tubing stringf and said wellv casing. '1-

Y VA further object' ofthis invention istoprovide. a metallic packer adaptedvtojfbe permanently, set in aiiuidtight manner, vand meansffor setting said packer by an explosive charger" Other objects and L advantages :ofrth'e 4present inventionvwill' become aappa'rent from the `folr n lowing description. takenwith reference to the drawing, whereinmr f Y n Figures `1 and 2l 'are *longitudinalY the`v presentinvention is 'to ews, .partly l in `cross'section oithepresentpacker and setting y means positionedwithinfa: well. wir 'r.

Figure 3 4is a longitudinal across-sectional-jlvew' y ofthe present packer afte well casing. pm;

a been se in a.

Referring to the drawing, the packer I0 of the present invention is shown as forming part of a tubing string comprising sectionsor lengths of tubing II and I2 threadedly'connected to the packer I0 at I3 and I4, respectively. 'The packer Illis formed of an easily deformable metallic tubularmember having a bore' I5f`adjacent the threaded ends I3 and I4 of said packer, said bore being equal in diameter to that of the adjacent pipe sections l I and I 2. At substantially the cen` ter of the packer,` the axial bore I5 is enlarged or recessed forming an annular groove I6. Prefer# ably,the innervwall ofthe packer Ill may'have formed' therein a second annular groove II'I adjacent the upper threaded end It. 1

I The Wall I8 of the packer ispreferably twice as thick as the wall of the adjacent tubing section II'. so that the wall 2G of the packer, adjacent v the annular groove I6, may be as thick as the tubing wall I9 and preferably: twice asthick. Thus the enlarged portions of the wall I8 'of the packer form-constrictions within vthe packer'lil in which a packer setting vmeansmay be posi: tioned. The height of the annular groove It'is at least equal tothe diameter of the' axial bore I5 of said packer IIJ. Formed on the outer surface of recessed wall 20 is one or more annular -grooves 2| adapted to` receive rand holdan vanik nular sealing element 22 which maybe of any `suitable'rnaterial as, for example, rubber,syn

thetic rubber, paint, a soft pliable metal :suchas lead, or any suitable plastic material. l Paints or plastic materials used as sealing elements in oil Well packers are preferably of a type unaffected bythe oil cir other materials encountered in an oil Welland of a type that'hardens andzsets against the wall of` a well casing 23V to prevent leakage.4 of` gas or liquids vertically past #any scored places in the casing wall after the vpacker hasbeenset. l t

The packer ID may be made of any suitable metal (or plastic) adapted to'be distenoled out-` wardly against the wellcasing 23 when subjected` to an internal force such as `one created when an explosive charge `is ignited, saidpackerf befcoming permanently formed in -its 'distendedI shape to pack off the annular space 4between av tubing string and the well casing. Atthe same time the bore I5 of the packer remains ,open and. in communication with thesections of tubing string II and I2 above and below.- Preferably thepacker is made of la deadfsoit low carbon an?- nealed steel or annealedextruded aluminum. y.A

higher 'carbon steel may also be used when the.= recessed wall portion 2li is annealeddeadsoft., The p acker may also -be `made of copper vor.anyU

bar to freely slide down said tubing string'and be` positioned in said packer Ill. #.One portion of the bar 24 is reduced in diameterforming. an annular groove 25 about said bar and a mandrel 32 about f which an explosive charge 26- maybe wrapped. The explosive charge 26 for expanding the packer I0 is carried in said annular groove 25, vsaidexplosive charge being either wrapped or formed vabout saidbarinv a manner such thatthe diameter. of theexplosive charge 261s no greater than that-.of the 'carrierI bar 24. Thus, when thevbar y24.and-explosive y26 .are positioned within the axialtboredofsaid packer I0, thefmandrel 32 andthe grooved or Y recessed wall. 20 form the inner v.and 4outer walls .of a *closed annular chamber.

...The-.corners -34-of the annular .groove-.25 are preferably `rounded* Ito robviate distortion of the baramember24 by forces .exerted by the explosive charge. In a. like-manner the corners-35 kof the annulargroove I6 in the .packer Ill arev preferably rounded 1 to eliminate .possible cracking. of the -wall 20. Y Sincethevbar Ymember '24 above and below'the.mandrelesection-A 32u areof thesame diameter, --an exploding charge exerts' the same pressure against the bar at both endsfof said mandi-c1132. .Hencethe bar 24.has no tendency to'movevertically at thefsame-timeof .the vdischarge.

f=Formed ordrilled inthe bar member 24vis a suitableholeor recessc2'I adapted to receive wa detonator (not shown) and a passageway 28 containing insulated electrical conduit means 29 forflringthedetonator an'd explosive charge 26. If azdetonator is notv used to set 01T the explosive charge, the electrical conduit .means -maybe run is substantially equal to the diameter of the axial bore of the packer thus forming means for closing the axial bore I5 of said packer I and restricting the flow of the expanding gases generated by the explosion when the charge 26 is detonated. Thus, the major portion of the explosive'forces is'directedradiallyto expand the packer-wall 20. It is realized that vwhen a packer IU- of an extremely soft material is employed it Ymay be desirable to use an explosive carrying .bar .24.of reduced diameter thus allowing some of an explosive force to be dissipated upwards 'fand downwards inthe tubing string II and I2 to prevent'the soft packer material from being shattered.

PreferablyVhoweven the forces generated by an exploding charge are controlled by a proper selectionfof the size and type of explosive charge used. Thus, an explosive is selected that det- -onates' with a 'force' sharp enough tol expand the IfpackerIIl withoutshattering'it. Since various explosives `of .'this' type yare well known :inthe field of :military and commercial explosives, they will notf-befurther described here.

In'operation, a metallic packer Ill ofthe abovedescribed' type i is .'coupled'between two sections II 'and "I2 of aitubingstring y3G and lowered intol a well 'casing 23'as shown inFigure 3. If avery softmetalpacker: I0. isemployed, and the length andweight of'the'tubing string I2 depending below the` packer II)y is` substantial, it may be desirable. tol mount a tubing' hanger, diagrammatically represented .at 31, on the tubing below-:saidy packer I0: for .anchoring the tubing .to the vcasing'23,fas' shown. In such a case the anchor '31 is actuated `by lmanipulation of the tubingstring 36 before thepacker` I0 is set. `The structure and operationof tubing. anchors, formf ing .no Ypart `of this 'invention and being vwell by means of the cable .29 whichfpasses over .a

directly frompassageway .'28 throughrecess 21 .n

to" the charge 26. lPreferably,1the yelectrical con-y duit ymeans is of the current-conducting an'd loadbearing typewhereby the explosive-'charge may'beflowered through the-tubing string II in the'well.

f Suitableimeans arefai-lixed' to Saidbarm'ember 24 for xedly positioning 'the 1 explosive 1. charge carried therebyoppositethe recessed wall portion 2010i said packer I0. In .the embodiment shown the' .positioning means f comprise a pluralityv of spring elements 30 xedly secured to and. radially extending from :a 'reduced upper portionz3 I' ofsaid bar member 24. The springs 30 are fadapted to expand intov the annular groove' I Tof. the packer I'0f' andlfprevent? furthery .downward travel of the barf member l 24. In.v this embodiment the f lower end-1133 tof the fbar. member `2I...forms va "sinker barV ofesuiiicent weight -to pull the'r bar tand attached-cable 29 down the well and into position inthe 'packerf IIl.` It is evident that thesinker barcould alternatively be positioned'abovethe spring elements `30 for pushing the springsl30, mandrel 32 and explosive charge "26 into-place'.

The barmember 24-is normally Vmade of steel in'order to withstand ther detonation of the-explosive charge without being shattered 1' or deformed. 'Y Preferably; the ldiameter of .thelrar'ZI pulley y38and is unwound from suitable winch means 39. As theidepth ofthe packerI IQ' is generally known by the numberV of lengths of tubing 26 vthat wereconnected togetherand run into the well, the vproper length of cablei2'9 is unwound.from1therwinchr39 .until the bar '24 is positionedfin'.thepacker I0. If the location of the packer I0 isunknown a sensitive weight indicator located at the surface (not shown) may be connected to or in contact with thecablev29,

said..indicatoribeing-factuatedSeach time. that the springs orv feelerwires '3D pass a groove or joint inthe `tubingxstring36. In either case the bar 24 .'mayfbe loweredvuntil the springs .are in the Y annular groove I6 of the .packer I02in order to accurately'positionrthe'bar. The Vbar 24 is then raised slightly until .the springs :'30 .seatv in the annulargroove I1 at which'time'the-explosive charge is exactly oppositethe'recessed wall 20 of thepacker II).

With the'bar24ipositioned in the packerl, an`A electric currentis sent down the cable. 29 fromany suitable 'power source at the surface to 'detonate theriexplosivefcharge.26. `The force of the explosion distends the recessed wall 20 of the .packer Illninto .substantially fluidtight permanentfcontact'with `thewell casing 23. as shown in Figure Sfafter the bar 24 has 'been hoisted vby the cable :29 .up the tubingl 36. The

' annular sealing element'22 carried bysaid packer 5 iluidtight` seal between the packer IIJ and the casing 23.

If desired, the upper threaded end I3 of the y packer l0 may be a left hand thread so that `the attached tubing section H could be disconnected by rotating the tubing string to the right from the surface. The packer l0, being made of relatively soft metal, could then be drilled out.

I claim as'my invention: Y

1. Apparatus for packing oli the annular space between an inner and an outer tubular string in a well, comprising, in combination, a cylindrical packer member made of deformable material having an axial bore therethrough, means at` either end of said cylindrical packer for con# necting said packer into the inner tubular string, said axial bore having constrictions throughout two spaced portions thereof, a cylindrical mandrel having two axially spaced portions of enlarged diameter, the diameter of said enlarged portions and the spacing therebetween being respectively equal to those of the constricted portions of the axial-bore, an Vannular explosive charge disposed around said mandrel between the enlarged por-r tions thereof, means for positioning said mandrel within the bore of said packer with the enlarged portions of the mandrel in register with the constricted portions of said bore, said means comprising an electric conductor cable attached to said mandrel, and means for exploding said charge by an electric impulse transmitted through said cable, said means comprising igniter passage means in said mandrel in communication between said conductor cable and said charge. 2. Apparatus for packing off the annular space between an inner and an outer tubular string in a Well,`comprising, in combination, a cylindrical packer member made of non-resilient deformable material having an axial bore therethrough, an annular groove formed in the outer wall of said cylindrical packer intermediate the ends thereof, sealing means carried in said annular groove, means at either end of said cylindrical packer for connecting said packer into the `inner tubular string, said axial bore having annular constrics tions throughout two spaced portions thereof, a cylindrical mandrel having two axially spaced portions of enlarged diameter, thediameter of said enlarged portions and the spacing therebetween being substantially equal respectively to those 'of the constricted portions of the axial bore, an annular explosive charge disposed around said mandrel between the enlarged portions thereof, means for positioning said mandrel within the bore of said packer with the enlarged portions of the mandrel in register with the constrictedportions of said bore, said means comprising an electric conductor cable attached to "said mandrel, and means for exploding said charge by an electric impulse transmitted through said cable, whereby said wall of said cylindrical packer member between said annular constrictions is expanded radially into fixed fluidtight `engagement with said outer tubular string.

3. Apparatus for packing 0E the annular space between an inner and an outer tubular string in a well, comprising, in combination, a cylindrical packer member made of a malleable metal having an axial bore therethrough, an annular groove formed in the outer wall of said cylindrical packer intermediate the ends thereof, sealing means carried in said annular groove thread means at either end of said cylindrical packer for connecting said packer into the inner tubular string, said axial bore having constrictions throughout two spaced portions thereof, a cylindrical mandrel'having two axially spaced portions of enlarged diameter, the diameter of said enlarged'portions and the spacing therebetween being respectively equal to those of the constricted portions of the axial bore, an annular v explosive charge disposed around said mandrel between the enlarged portions thereof, electric conductor cable means attached to said mandrel for lowering said mandrel through said inner tubular string, spring means for positioning said mandrel within the bore of said packer with the enlarged portions of the mandrel in register with the constricted portions of said bore, and means for exploding said charge by an electric impulse transmitted through said cable, said means comprising igniter means in said mandrel in cornmunication between said conductor cable and said charge.

4. Apparatus for packing off the annular space between an inner and an outer tubular string in a well, comprising, in combination, a non-resilient deformable metallic tubular packer having an axial bore therethrough, an annular recess in the inner Wall of said tubular packer intermediate the ends thereof, means for securing the open ends of said tubular packer into said inner tubular string, cylindrical mandrel means adapted to be slidingly passed through said inner string and said tubular packer for substantially closing the ends of said tubular packer, said mandrel means having an annular groove in its outer surface with the diameter of said mandrel means being substantially equal to that of the axial bore whereby a substantially pressure-tight annular chamber is formed between the mandrel means and the recessed inner wall portions of said tubular packer, an explosive charge carried in the annular groove of said mandrel means, means for removably positioning said mandrel means'within the bore of said packer with the explosive charge carried by said mandrel in register with the recessed wall portion of said packer, said means comprising an electrical conductor cable attached to said mandrel, and means interposed between said cable and said charge for exploding said charge by an electric impulse transmitted through said cable, whereby the recessed wall portion of the tubular packer is expanded into rigid fluid-tight contact with said outer tubular string.

WILFRED S. CRAKE.

No references cited.

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