|Publication number||US2493650 A|
|Publication date||Jan 3, 1950|
|Filing date||Mar 1, 1946|
|Priority date||Mar 1, 1946|
|Publication number||US 2493650 A, US 2493650A, US-A-2493650, US2493650 A, US2493650A|
|Inventors||Althouse Jr William S, Baker Reuben C|
|Original Assignee||Baker Oil Tools Inc|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (11), Referenced by (35), Classifications (9)|
|External Links: USPTO, USPTO Assignment, Espacenet|
Jan. 3, 1950 R. c. BAKER ETAL VALVE DEVICE FOR WELL CONDUITS Filed March i, 194e Patented Jan. 3, 1950 of California' Application March"v 1', 1946,.Serial"No. 6512053.i
1T6"Clairr1si` (Cl- 1662-1?) This' invention'. relates" tol wellv apparatus', and" more'-1oarticularl5r to valve'4 devices -for controlling uid. ilbw Virr conduits positioned' in" well bores.'
Cntrol" of` the-1 passage' off fluid Withinfa well conduit islsometimes" determined Y by a'- valve ele-'- menti th'at' is'v allowed to"'gravitate, or' be otherwise'i lowere'df through the' conduitA fluid; into' sealing# engagement@ with" a' companionf seating member;` In1some forms-'off'apparatussuch as siiieported casin'gf orf-cementingapparatus, it`
mayA be-A desired* to"y close' the" passage through a'sleeve-i-'valvemember disposed voriginally overv theports* tofJ enableu hydraulic" shifting of the sieeve f toNA a3 positinfuncovering the ports; per' and'exteri'orof tlfewell xiconduit.
l Oitentimesg'- difficulties 'are' encountered in ob= taining gravitation of thelvalve'member through viscous-1 drilling iluidis' inlthwwelll conduit, or" if triervalve"J member dees gravitatefthrough such`- fluids; it'des so=-very=fslwl consumirx'gjvaluable` Where= thee valves member is used ir'r a` multiple"i stage'cementing operation; its" speedy' .ie'scentr into'f-enga'gementwitlia sleeve" valve 'is' liigihlywpreferable; in order toopen th'efportsJ cov'- ered ib'y svtlfie'- vsleevevalve;` before'th'e 'cementslurry' tha-ttmightiliavebeen-deposited' 'around the ports" in': theflower stagefr cement/ing' operation' has an Ai furtlierfv disadvantage-v of the-1 present gravif tational types of Valve members is theirf'tendency' te'. bounce; 1 bump'fandj gyrate along the-*walls of thief:condixlts1throughA whichfthey are dropping,
whih'inot :only slows itheir descent 'through f the conduit?. but frequently damages their' sealing4 surfacesfandxprevents their eflicientf-sealin'gwith: tlievmating'fseat Yin-the sleeve'evalve or"otlfier 'well conduit-Ilmefmber: Another'difliculty in" providing a: propere" lalrproof-f seal-- is encountered* upon' inclination off! the'- gravitational valve "member witlif-respectito `the-*wellj conduitaxis: The v"shape ot1""the2'rvalvef member 'may not' permit "material deviation ifrom 1a' coaxial position' in the conduit; andf'stillr'a'llwifrmation' of1a '1eak-proo seal with' iter coengaging'f seat The* requirement': for an' ambient leak-'proof 1 seal underl all4 operational conditionssbecomesof utmost' importance* when' ardea'd'colmn ofi'ilui'ds' present 'below' a. sleeve:
vali/eon-fwhich thefvalve memberA is* to 'seat, in-
a'smuch asfasslightileaklma'yfpreventitliebuilding?l upcy of itlie-frequired '-'pressure differential across' the` sleeve* Valve? toi'- ect'i' its shifting" to port open-ings'position; that is; the -r-pressur'esron both sidesfpfthe sleeveva1veandfengaging valvemember become substantial-113'equalized preventing" f hydraulieereleasefandfshifting--fof thea former.'
2%' A further objectoitheinvention'is to 'provide awvalve member-which isnotlonly capable-ofrapid: downward travel through* the well'f fluid,` asV` set' forth above; but'iwli'iohff is also readily drillable 'to facilitate'its removal from the well c'onduit'iafter' ithas "served itsl purpose l'0i closing the conduit' bore;
Still another* obj e'ctv o'fi'the invention4V is' to'pro-- vide avalve memberf'having'such characteristics" as vto substantialh'frediiceits l'tendency to bounce;
bump -and gyrat'ealong the' Wall 'of''the 'Well 'con-A duitwhile gravitating'" to its* companion valvev seat in the'y conduit? A further object 'of'1r tlieinventin is to 'provide af; valve -member` capabley of 'i making: an efiicient seal against a companion valve seat in a wellconduit f irrespective* offtle inclination* of the valve member y'rela-tivetb thee-conduit axis? This 1-inventionllas'other-f'objectsl that will lb'e'- come' apparentfr'omf-aconsideration of 'thereinb'cdiinent shown'fin =-the'^^"drawings= accompanying and@ frming/` partiof?? the presenti' spe'ciiicatlon;
trate' -the general "f principles vlof fthe invention', but it'is to be understood tliatisuclii detailed'de'scrip- Figure lis a'flong-itii'd-ina'l'sectiorr'through a'well casing, 1 wfitlftheirvali'erdevice parts" disclosed l in onerelativer-position? Figure 2 is a view-asimil'ar'to Figure'fl;y with theA gravitational valv'e''memberin' inclined* position;
The -inventief-1 disclosed? byA way of" example inz: the# drawingsY .-applied' to al string of well casing having-'1' a-f' collar''` lf'connecting 'adjacent upper' and' lower casing-1'v sections' I I I 2 l together inspa'ced-relatin. Thisfcollar'has lateral ports I3f` normally" closed by'a'- sleeve valve" III having side seals" I5 engagln'gthei'wall offthe' collaron The' sl'evezvalve is` held in this closedpositionmri'ginalli'bvone or The `'sleeve :valve'hasra'fcentral passage "I I v whose Ward and-`outward"'direction'from am'edial throat' I 9 jto 'form an"inclined'seatingsurface"for a com- Fanion'4 valvefmem'ber 201 Tl'feivalve member is.l Y of 'the gravitational '"tvpe': andisdesi'gnedlo dropY downwardly'througl"tlewell casing or conduit into' engagement" with' "tle"'seat I8"`in the sleeve valvey-` i',o"'closl= its"` centiial' passage. Iland allow 60 the pre'ssureof the ilid the casing' above 3 the valve member and sleeve valve Ato be increased sufficiently for the purpose of shearing the screws I6 and shifting the sleeve valve member I4 downwardly to port opening position, as determined by abutting of the lower end I4a of the sleevel with a suitable stop, which may be the upper pin end I2a of the lower adjacent casing section I2. With the ports I3 in this position, fluid may be circulated from the-interior of the well casing, through the open ports to the casing exterior.
The gravitational type of valve member includes a hollow body 2| of generally tear drop, streamlined shape, filled either completely or partially with a relatively dense weighting material 22, such as lead or mercury. The forward or nose end 23 of the body is of spherical shape, with a spherical seal 24 of rubber or other elastic material mounted on it. As disclosed in the drawings, the nose 23 of the body has a hemispherical surface 23a adjacent an external body groove 25, the seal 24 also being hemispherical and merging into an upper rim 26 of cylindrical exterior having an internal flange 21 positioned within the body groove. Actually, the seal 24 is made slightly smaller than the forward end 23 of the body,V in order to be stretched over the latter and obtain secure andsnug engagement between the contacting spherical surfaces and between the flange 21 and surfaces defining the body groove 25.
The rearward portion 28 of the body is generally conical or conoidal in shape, converging gradually from the nose portion 23. Stabilizing ns or vanes 29 are disposed at the rear end of the body and are generally radial of the body to prevent gyration of the valve member as it is dropping through the wellY conduit.
The outer spherical surface 24a of the ,valve member seal 2,4 is of such a diameter with respect to its coengaging seat I8 in the sleeve valve as to make a continuous circular seal therewith,V
which is completely leak-proof regardless of the position of inclinationrthat might be assumed by the valve member 20 relative to the conduit and sleeve axis. The valve member is made sufficiently long with respect to the external diameter of the sealing surface 24a of the seal that, when engaged on'the sleeve valve seat I8 with the ns 29 disposed against the wall of the conduit, the outer spherical surface 4'24a of the seal still makes a complete circular seal with the inclined seating surface of the sleeve valve. As shown in the drawings, the length of the valve member is about three times the external diameter of the seal, but this Vproportion may be altered, depending upon the inside diameter of the casing in which the member is used, the external radius of the seal 24, and the extent of lateral projection of the ns 29, which are illustrated as extending outwardly from the axis of the body about the same distance as the radius of the external sealing surface 24a.
`As shown in the drawings, when the valve member 20 engages its seat I8 in coaxial position, a uniform,l circular elastic seal is made with the seat, and leakage therebetween cannot occur (see Figure 1). Upon inclination of the valve member with respect to the axis to its fullest extent, as when the ns 29 are engaging the wall of the casing (see Figures 2 and 3), the spherical surface 24a is still making a complete circular seal with the seat of the valve member, having merely rotated several degrees about its center 24h. As a result of the spherical seat contacting surface 24a, various degrees of inclination of the valve member with respect to the axis of the conduit and sleeve valve still produce an eflicient seal that is leak-proof in all respects. The leakproof characteristic is materially enhanced by the rubber or other elastic material of which the seal 2li is made, which makes it conform with minor irregularities or depressions that might be found in the seating surface I8 of the sleeve valve I4. Moreover, it is to be noted that the radius of the exterior of the body nose 23 itself is greater than the radius of the sleeve throat I9, to insure compression ofthe elastic sealing material between the body 2I and sleeve I4 upon imposition of pressure on the body, and to forestall potential dissipation of the seal by hydraulic pressure action thereupon, which might occur if the bodynose radius were less than the throat radius, and thus allowed a substantial annular space through which the seal material could be blown.
The descent of the valve member 28 through the fluid in a well conduit is accelerated substantially by use of the body '2| containing kthe heavy lead or other weighting material 22. lIt is to be noted that most of the weighting material isin the leading portion of the body, which maintains its center of gravity closer to the spherical seal 24 and facilitates dropping of the valve member in a straight line through the Well conduit. Such straight line dropping is assisted by the gyration preventing action of the stabilizing ns 29 while the valve member is gravitating through the casing uid.
The lead weighting material 22 adds substantially to the gravitational force available in moving the valve member downwardly through the fluid in the well conduit, since it adds more weight per unit of frontal area of the valve member displacing the uid to one side. Such descent or gravitation of the valve member is further enhanced by the tear drop or streamlined shape of its body, which allows a minimum of fluid eddying or drag on the valve member, and insures smooth streamlined uid flow thereover as the valve member passes downwardly through the casingr uid.
The hollow body 2l of the valve member is made of a suitable, rigid, drillable material, such as magnesium alloy or aluminum. This body has a relatively thin section to permit the use of a maximum amount of lead weighting substance 22. The use of a substancelike magnesium alloy or aluminum for the body 2l provides a material capable of resisting'much more marring or deformation than the lead material itself, and retains the entire valve device in its initial undeformed condition during its descent through the well conduit into engagement with the sleeve valve. The use of lead, or a similar pliant material, alone for the entire valve member would subject it to substantial deformation during downward descent through the well casing, and possibly result in its failure to seal properly with its mating valve seat. However, by combining f the two materials, namely, an envelope 2I of rigid and nondeformable magnesium alloy or aluminum lled with an internal weight of lead or `similar substance 22, the gravitational advantages of the lead are stained while its deformation Ydisadvantage is eliminated.
In the use of the arrangement disclosed forY multiple stage cementing purposes, let it be assumed that cement slurry has been displaced from the well conduit at some point below the collar I0, as through a casing shoe (not shown).
amg/sbo :55 l` Thereafterjthe valve member 20 is droppedxfrom fthe top,v of .thef-well *bore :through :the well .econr4duit'and Adescen'dsaspeedily .into engagement with the valve .seatrl to@ allow fluid Y'pressure to vbe ."ibuiltupfor the purposeifofsrshearingvthe screws vI6 :and `shifting'rthe `valve f t4 downwardly kto port opening position. Such Arapid travel v:insures opening-tof the .ports -I 3 r prior .to 'the 4'tirn'e'"th`at any cement slurry, whichi1=imay t have been. rdeposited aroundfthef.ports:1byfthe lower stage cementing ioperation;,hayan-.opportunity of taking an initial set. This port enclosing slurry, which is still in a plastic 'statefwhenftheports are opened, -,can-abe.,.circulated readilyjfrom ,the :annulus yaround the casing by pumping-rluidfdown the casing and out of the ports. l
Ordinarily, inthe performance ofmultiple stage cementing operations, the vfluid below the-zupp'er stagezcollar is a dead, substantiallyincompressible column after the lower stageahasbeen cemented. The making of an eflioient seal under fall condi- :tions 4'between the valve member 2B and :thefsleeve 'valve ..If4 thus becomes of Aparamount importance, .-si-nce :evena'slight degree ofi-leakage would equal- .ize theepressures on both sides `oi the sleeve valve and preclude shearing-ofthe screws l5, which,fof course," would Avprevent o peningfof tl'iefip'orts:i |33. By :applica-nts arrangement, an :eicient'se'al-is 4obtainedvgandport opening assured.
Although described in conjunction with a sleeve valve for controlling lateral ports in a well conduit, the valve member has other uses. For example, it could be employed as a bridging member to close the bore through the well conduit by engaging an immovable seat therein.
After the cementing operation has taken place and the cement has hardened, it is usual practice to drill out internal casing obstructions. The running of a drill bit in the casing to the position of the valve member 2l) and sleeve I4, and the drilling out of these two members7 can take place very readily, since they are all made of readily drillable materials.
Having thus described our invention what we claim and desire to secure by Letters Patent is:
1. A valve device for gravitation through a well conduit, including a hollow impermeable body of generally tear drop shape having a spherical nose portion and stabilizing fins on its tail portion, and a weighting material in said hollow body having a greater specific gravity than the material of said body.
2. A valve device for gravitation through a well conduit, including a hollow impact resisting body having a forward portion whose outer surface is a segment of a sphere and a rearward portion converging gradually from said forward portion, and a weighting material in said hollow body having a much greater speciiic gravity than the material of said body.
3. A valve device for gravitation through a well conduit, including a hollow body of readily drillable material having a generally spherical forward portion and a rearward conoidal portion converging gradually from said forward portion, a unitary readily drillable weighting material in said hollow body having a much greater specific gravity than said body material, and radial ns secured to and extending from said rearward portion.
4. A valve device for gravitation through a well conduit, including a rigid, non-deformable hollow body having a generally spherical valve seating surface thereon and a hollow portion extending longitudinally from said surface, and a weighting 1 6 '.--lmalterialT in: saidihollow fbody izsubstantiallyicom'- pletelyallingsaid.longitudinally extendinglhollow fiportionandihavingagreaterspecic gravity than the material of said body.
5. .A'valvedevicefor gravitation through a' well Lconduit, includinga rigid,frnon-deformable1'hollow bddy'vof I`readilyv'drillablef'fmaterial :having a valve seatingsurface f thereon :and a hollow `.portion ex- -tending longitudinally from said surfaceg-andfa .readily drillable weighting material filling `said I-zhollow body, .includinglsaid longitudinally extending hollow portiongfand Yhaving1amuch"gr.eater .fspecicfgravity thanthematerialof said body..
166. Aova'lve deviceffor use "ina well conduit, .including axrigidfbody of .readily ldrillable mate- `rial-having afspherical noserportionand a circular :groove 'adj acentsaid porti'on, 'said 'body further :including a longitudinally `extending portion :converging ,gradually'from' said nose portion, and fan elastic spherical'-'fsealfniountedv on said body-"1in snug engagement with said spherical nose *.port-ion and 'merging :smoothly into .said 'longitudinally 'extending portion, saidfseal having a flange-positioned vwithin said groove.
y =7..-A valvefdevcefor :use iin a wellmconduit, including a r-hollovvf body having' a :spherical-:ror- Ward portion and a rearward conoidal .portion merging substantiallyinto and lcon-verging grad- .uallyrfromsaid forward fportion, afiveighting material in said hollow body having a much greater specic gravity than the material of said body, and an elastic spherical seal on said spherical forward portion.
8. A valve device for use in a well conduit, including a hollow body of readily drillable material having a spherical forward portion and a rearward conoidal portion converging gradually from said forward portion, said body also having a circular groove adjacent said forward and rearward portions, an elastic spherical seal mounted on said body in snug engagement with said spherical forward portion, said seal having a ange positioned within said groove, and a readily drillable weighting material in said hollow body if having a much greater specic gravity than said body material.
9. A valve device for gravitation through a well conduit, including a hollow body of generally tear drop shape having a spherical nose portion and stabilizing iins on its tail portion, a weighting material in said hollow body having a greater specific gravity than the material of said body, and an elastic spherical seal on said nose portion.
l0. A valve device for gravitation through a well conduit, including a hollow body of readily drillable material having a generally spherical forward portion and a rearward conoidal portion converging gradually from said forward portion, a readily drillable weighting material in said hollow body having a much greater specific gravity than said body material, and an elastic spherical seal on said forward portion.
1l. A valve device for gravitation through a well conduit, including a hollow body of readily drillable material having a valve seating surface Atudinally from said surface, and a Aweighting material insaid hollow body and its hollow portion having a greater specific gravity than the material of said body.
13. A valve device for gravitation through a low portion and having a greater specific gravity Vthan the material of said body.
14'. A valve device for gravitation through a well conduit, including a rigid, non-deformable bodyvof readily drillable material having a valve seating surface thereon anda hollow portion extending'longitudinally from said surface, and a readilydrillable weighting material filling said hollow portion and having a much greater specic gravity than the material of said body.
15. A valve device for use in a well conduit, including a body having a spherical forward portion and a rearward conoidal portion converging gradually from said forward portion, and an elastic spherical seal on said spherical forward portion merging smoothly into said conoidal portion. Y
16. A valve device for use in a well conduit, including a body of readily drillable material having a spherical forward portion and arearward conoidal portion converging gradually from said forward portion, said body also having a circular groove adjacent said forward and rearward por- .tions, an elastic spherical seal mounted on said body in snug engagement with said spherical forward portion and merging smoothly into said conoidal portion, said seal having a flange positioned within said groove.
REUBEN C. BAKER. WILLIAM S. ALTHOUSE, JR.
REFERENCES CITED YThe following references areof record in the
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US373440 *||Oct 30, 1885||Nov 22, 1887||Apparatus for sinking wells|
|US455913 *||Jan 2, 1891||Jul 14, 1891||Means for equalizing the pressure of gas in gas service-pipes|
|US1040226 *||Aug 21, 1912||Oct 1, 1912||Charles De Lukacsevics||Siphon-head.|
|US1579140 *||Jun 14, 1924||Mar 30, 1926||Luzerne Rubber Company||Ball cock|
|US1640408 *||May 20, 1926||Aug 30, 1927||House John W||Standing valve|
|US1673616 *||Oct 1, 1925||Jun 12, 1928||Alexander Boynton||Method of and device for cementing wells|
|US2002783 *||Jul 31, 1933||May 28, 1935||Long Jon R||Valve|
|US2240119 *||Nov 2, 1938||Apr 29, 1941||Permutit Co||Adjustable venturi tube|
|US2250813 *||Aug 17, 1937||Jul 29, 1941||Rea Philip M||Means for hermetically sealing fluid pressure|
|US2330267 *||Apr 3, 1942||Sep 28, 1943||Baker Oil Tools Inc||Well cementing apparatus|
|US2338719 *||Nov 20, 1942||Jan 11, 1944||Holt Pliny G||Surface marking signal|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US2627314 *||Nov 14, 1949||Feb 3, 1953||Baker Oil Tools Inc||Cementing plug and valve device for well casings|
|US2645288 *||Jul 23, 1951||Jul 14, 1953||Johnston Testers Inc||Back circulator device|
|US2651367 *||Nov 14, 1949||Sep 8, 1953||Baker Oil Tools Inc||Plug device for well conduits|
|US2651368 *||Nov 14, 1949||Sep 8, 1953||Baker Oil Tools Inc||Plug and valve device for casing apparatus|
|US2662599 *||Nov 14, 1949||Dec 15, 1953||Baker Oil Tools Inc||Well casing cementing plug and valve device|
|US2662600 *||Nov 14, 1949||Dec 15, 1953||Baker Oil Tools Inc||Well cementing plug|
|US2870784 *||Jan 19, 1955||Jan 27, 1959||Walter Walls||Drilling string float valve|
|US2943684 *||Feb 13, 1958||Jul 5, 1960||Ramsey Smith||Selective hydrofracting apparatus|
|US3211232 *||Mar 31, 1961||Oct 12, 1965||Otis Eng Co||Pressure operated sleeve valve and operator|
|US3326520 *||Mar 25, 1964||Jun 20, 1967||Rubber Electronic Ind||Resilient needle valve element|
|US3552412 *||Oct 19, 1967||Jan 5, 1971||Hagar Donald K||Drill string dump valve|
|US4512406 *||Jun 7, 1982||Apr 23, 1985||Geo Vann, Inc.||Bar actuated vent assembly|
|US6923255 *||Aug 2, 2001||Aug 2, 2005||Paul Bernard Lee||Activating ball assembly for use with a by-pass tool in a drill string|
|US7866396 *||Jun 6, 2006||Jan 11, 2011||Schlumberger Technology Corporation||Systems and methods for completing a multiple zone well|
|US8662178||Sep 29, 2011||Mar 4, 2014||Halliburton Energy Services, Inc.||Responsively activated wellbore stimulation assemblies and methods of using the same|
|US8668012 *||Feb 10, 2011||Mar 11, 2014||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US8668016||Jun 2, 2011||Mar 11, 2014||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US8695710||Feb 10, 2011||Apr 15, 2014||Halliburton Energy Services, Inc.||Method for individually servicing a plurality of zones of a subterranean formation|
|US8893811||Jun 8, 2011||Nov 25, 2014||Halliburton Energy Services, Inc.||Responsively activated wellbore stimulation assemblies and methods of using the same|
|US8899334||Aug 23, 2011||Dec 2, 2014||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US8991509||Apr 30, 2012||Mar 31, 2015||Halliburton Energy Services, Inc.||Delayed activation activatable stimulation assembly|
|US9303501||Oct 30, 2015||Apr 5, 2016||Packers Plus Energy Services Inc.||Method and apparatus for wellbore fluid treatment|
|US9366123||May 1, 2014||Jun 14, 2016||Packers Plus Energy Services Inc.||Method and apparatus for wellbore fluid treatment|
|US9428976||Jan 15, 2014||Aug 30, 2016||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US9447658 *||Nov 27, 2013||Sep 20, 2016||Baker Hughes Incorporated||Chemical injection mandrel pressure shut off device|
|US9458697||Feb 24, 2014||Oct 4, 2016||Halliburton Energy Services, Inc.||Method for individually servicing a plurality of zones of a subterranean formation|
|US9784070||Jun 29, 2012||Oct 10, 2017||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US20040011566 *||Aug 2, 2001||Jan 22, 2004||Lee Paul Bernard||Activating ball assembly for use with a by-pass tool in a drill string|
|US20080000697 *||Jun 6, 2006||Jan 3, 2008||Schlumberger Technology Corporation||Systems and Methods for Completing a Multiple Zone Well|
|US20120205121 *||Feb 10, 2011||Aug 16, 2012||Halliburton Energy Services, Inc.||System and method for servicing a wellbore|
|US20150144352 *||Nov 27, 2013||May 28, 2015||Baker Hughes Incorporated||Chemical injection mandrel pressure shut off device|
|DE931140C *||Mar 1, 1950||Aug 1, 1955||W Krueger Fa||Selbsttaetiges Rueckschlagventil|
|DE1008974B *||Feb 26, 1955||May 23, 1957||Kuehn O H G Geb||Rueckschlagventil mit einteiligem Gehaeuse|
|DE3134767A1 *||Sep 2, 1981||Mar 17, 1983||Welland & Tuxhorn||Regulating valve for fluids|
|DE29704033U1 *||Mar 5, 1997||Apr 10, 1997||Xomox Int Gmbh||Ventil|
|U.S. Classification||166/194, 251/357, 166/318, 137/71, 137/797|
|International Classification||E21B34/00, E21B34/14|