US2652894A - Hold-down slip assembly for well packers - Google Patents

Description

p 22, 1953 c. c. BROWN ETAL 2,652,894

HOLD-DOWN SLIP ASSEMBLY FOR WELL PACKERS Filed Aug. 9, 1948 3 Sheets-Sheet l 0.0. aaown F.L. SCOTT JR. JNVENTORS ATTORNEY P 1953 c. c. BROWN ETAL 2,652,894

HOLD-DOWN SLIP ASSEMBLY FOR WELL. PACKERS Filed Aug. 9, 1948 3 Sheets-Sheet 2 0.0. BRQWM EL. SGOTT JNVENTOR ATTGRNEY Sept. 22, 1953 1. C. BROWN ET AL HOLD-DOWN SLIP ASSEMBLY FOR WELL PACKERS 3 Sheets-Sheet 3 Filed Aug. 9, 1948 FIG.8

0.0. BROWN EL. SCOTT JR.

INVENTORS ATTORNEY FIGJ Patented Sept. 22, 1953 STATES PATENT OFFICE 2,652,894' HOLD-DOWN; SLIP ASSEMBLY FOR WELL PACKERS Cicero. (I grown and Floyd L. Scott, .l' n, Houston T x; an S assiglrir a" 'a dlim nj Application August 9, 1948, Serial No. 43,295

8 Claims. 1 661-12),

a bolala s. sli and par ic larly o a "n ss lnblx i42 holdi own; e; cker. a ainst nrssil es exe e u wardl ther wq nve i i iial aqksrs m a b ar a i-ng sleeveof n rm ly ha e h r qqw Wi ydir ct d able v a set otpipe=gripping slips which, under own ard. P essur splied; to. the upper n o the e s s ssra a e ra a l e nd n anaemiae han th s .125 ta onar bas a a n t hi h; t s n sle ve ma b c meress b t do wa dl plie P ess to e ect bs e u site r d expansion hsr q iQ s aL ns-thsca ins- Es h r-s th s e are mmon called of the expander. nto. the casing provides a awsl H qkq f and. d p 41 3 eil ppliedrom abov t drive he s i i a i o. gri in en a m o n y. t ne ma r lea ed b applying? a p a pull to. the slip espanden Such packers, therefore. when subjected to high pressures from holes an pa t cular w en subjec edto s r s or} pressure from the, well, as commonly occur, be. aqqid lital r le ed by c ar direct d presets and i e u ar y e as na. O ten. result n i n esi eak-se 9 wel fluid pastthe packer and sometimes serio1- 1 s amass, to h ack an sums th s e eased- In an attempt to overcome this diiliculty many dif ere t r cture have b n sisn d- Pr ci 6 3 11 5 1 .31% 2 3 i 1 p iQB. 9 q-nal sds. ho s-d wn lipv sem hi h xstal s w s t o a sec nd s t o slips, a in llfi l acin W il m unt or} 0 9 cab -m t acin in t pward direction, th s t ucture, b in nc ine abovethe s al n ve.- lQ l P fi fie. fi i fifi be gativ 2 .9 1 to constr ct. a se the. p i a bri a s require. relatively. complicated setting mocha; nisins, are diiiicn-lt to release when it is desired .0. Wi hd lw i 2 N 33. n ha e 70? ene allvfifiiWtQtd, i P 9 i l n u eeqqosiins a h s in ent n f ts, Pr cipal objects: the provision of a novel hold-down slip assembly for packers; which is of Very simple form and: relatively cheap to construct; which may be. Llfifid with Various conventional packers;

agement with the casing by th corth we l ave res:

wh h er s. ery i i el is 9111 do n the ac et wh le. i .tins n. ifi'c en a w ic i asil set and e a i s m c n na qperationselnployed in sett n and releasing the more. conventional types. of packers; and which, in general, overcomes- 0r obviates the several disadvantages common to more. conventional packers,

Qther and more specific objects and advantages of this invention will become. apparent from the follow n detailed description when read in conjunction with the accompanying drawings which illustrate. useful embodiments in acc rd nc th th s in ention na amn F i a u r ei-s t n l. e s i sl e f: one sibqdimsnt o t i emb n a Q anq th h ni nt ba w ich they slips are combined with ain casing sealing. structureqf the packer, the trncture being shown in a well a in wi the arts n. h i positions prior t0 fi l gi and th mor csnwn Parts of; the packer structure, being illustrated in broken lines;

Fig. 2 is a viewsirnilar to Fig. 1 the parts being shown in their positionszafter setting;

Fig. 3; is an enlarged fragmentary sectional view taken along line 33 oi-liig, 2;

Fig. 4 is a cross-section along line 374 of Fig. 2;

Fig. 5 is a cross-section along line 5-75 of Fig. 2.;

Fig. 6 is a perspectiv view of one of the holddown slips forming a part of the assembly of Figs. 1 and 2;

Fig. 7 is a quarter-sectional elevation of an other embodiment oi a slip assembly in accordance with this invention, showing the parts there:- of before setting;

Fig. 8 is a View similar to Fig. 7 position of the. parts aftersetting in a well casing;

Fig. 9, is a longitudinal sectional View of one of the slips forming a part of; the structure illusated in F gs. 7' and, nd

Figs. 10' and 11 are a front elevation and an end-.view, respectively, of the slip illustrated in Fig. 9.

Referring to the drawings, the embodiment illustrated particularly in li igs. 1 to 6, inclusive, comprises a generally tubular sealing sleeve l2 constructed of a iieaible, resilient rubber or rubber-like composition conventionally used for u h eal n s eev s- I w l be understood ha sleeve l 2 may have moldedtherein layers of fabno. o other mate ial suita o str n t n n showing the iend-wise thrust of sleeve l2 longitudinally compressed to effect radial ex- ,1

the sleeve under the forces to which it will normally be subjected. Upper and lower metallic cellars i3 and. M, respectively, are connected to the opposite ends of sleeve 52, and made integral therewith by being vulcanized. thereto during the molding of the sleeve. The exteriors of collars E3 and i i are provided with a plurality of angularly spaced radially extending studs [5 and 16, respectively, between and about which may be stretched a metal wire reinforcing cable H for increasing the tensile strength of the sleeve, the wire being incorporated therein during the molding of the sleeve. The intermediate portion it of the wall of sleeve I2 is made somewhat thicker than the ends thereof to thereby reduce the diameter of the bore of sleeve l2 relative to its ends and oppositely tapering surfaces It and 2!], respectively, extend from the ends of intermediate portion E8 to the adjacent ends of the sleeve, to form smoothly tapering surfaces therebetween.

An annular flange 2| is provided on the exterior of collar [4 spaced below studs Hi, the external diameter of flange 2i being made such that its outer periphery will be substantially flush with the exterior of sleeve 12 in its normal unexpanded position, as illustrated particularly in Fig. l. The upper face of flange 2! will thus form the metallic base to receive the when the latter is pension thereof. A circular coil spring 22, commonly termed a garter-spring is embedded during the molding of sleeve 12 in the lower end thereof so as to encircle the portion of the periphery of collar Hi between studs l6 and the upper face of flange 2!. The lower end of collar M is externally threaded at 23 for attachment to the usual conical slip expander 24, the latter carrying the usual segmental casing-gripping slips 25. hingedly connected to a conventional cage 2'6 (Fig. 2), and other parts of a more or less conventional packer structure. Since this slip expander assembly forms no part of the present invention, and may be of any more or less conventional construction, these parts are indicated in broken lines in their normal operative relationship to the sealing elements constituting the present invention.

The upper end of collar [3 is externally threaded at 2'5. A metallic seat ring 28, having an inwardly tapered seat 29 about its upper edge is screwed over the upper end of collar 13 and is dimensioned so that its bore will be substantially flush with that of collar l3 and its outer periphery will be substantially flush with that of sleeve l2 in the latters unexpanded condition. Ring 28 is provided with a downwardly extending peripheral skirt 30 having an inwardly extending lip 3 l, the inner end of which is spaced from the exterior surface of collar l3.

A plurality of pipe gripping slips 33, having upwardly facing teeth 34 on their exterior surfaces, are embedded in the exterior surface of sleeve l2. Slips 33 are preferably cut from a circular collar of substantially the same external diameter as that of sleeve l2 in its unexpanded state, so as to form a substantially solid ring about the sleeve, which because of its segmental form will be expandible with the sleeve with a minimum of spacing between the segments when the sleeve is expanded. Each of the slips 33 is provided with an elongated shank 35. the upper end of which is provided with an outwardly facing generally C-shaped head 36 adapted to enclose lip 3i and form therewith a loose hinge conwhen the latter is nection between ring 28 and each of the slips. It will be understood that in assembling the sealing structure, slips 33 will usually be connected to ring 28 by booking heads 36 over lip 3| and then collar 13 will be screwed into ring 28 to hold these elements in their relative positions for insertion into a mold for molding sleeve [2 thereto.

In the molding operation, the material forming sleeve l2 will enter all of the free spaces between and about the described hinge connection so that all of the parts of this structure become, for all practical purposes, integral parts of the sealing sleeve, slips 33 being so disposed that teeth 34 will be substantially flush with periphery of sleeve l2.

The above described sealing assembly, when installed as a part of a conventional packer structure, is employed in the following manner: As noted previously, the sealing assembly will be connected to the usual conical slip expander 24 on which are slidably mounted slips 25 arranged to expand in response to downward movement of expander 24 to engage a well casing C to hold the packer structure against downward movement in the casing. A conventional packer setting tool, indicated generally by the numeral 31, is shown in broken lines, being shown in Fig. 1 in its position prior to setting of the packer and in Fig. 2 after setting of the packer. Setting tool 31 includes a tubular stem 38 which is movable axially of the packer. It will be understood that the usual releasable connection (not shown) is provided between stem 38 and the packer structure for holding these elements against relative longitudinal movement while the packer is being run in the well, and which, upon release, permits the setting tool to be moved axially relative to the packer. The upper end of stem 38 is provided with the usual tubular setting mandrel 39 of a diameter adapted to radially expand sleeve l2 when forced through the bore of intermediate portion is. Mandrel 39 has mounted thereon the usual annular valve 40 which is adapted to engage the upper edge of seat ring 28 and to exert thereon the weight of the usual pipe string 4! which is connected to the upper end of the setting tool 31 and extends to the top of the well from which it is suitably manipulated to set or release the packer in the conventional manner. It will be understood that cage 26 carries conventional friction elements, illustrated fragmentarily at 42 (Fig. 2), to hold the slip and cage assembly stationary, while setting tool 31 is rotated sufficiently to effect release thereof from the slip assembly in order that the setting tool may be moved axially of the packer for effecting setting or release of the packer.

With setting tool 3'! thus released it will be lowered by lowering operating pipe 4! at the top of the well until valve 40 engages the top of seat ring 28 whereupon the weight of the operating pipe. being thus applied to the top of the packer structure will begin to compress the latter. The end thrust on sleeve l2 drives expander 24 down inside slips 25 and forces them outwardly into tight gripping engagement with casing C, stopping the downward movement of expander 24. This will, of course, stop further downward movement of collar l4 and flange 2| and the continued application of the weight of the operating pipe will now serve to further compress sleeve 12 and cause its expansion radially into tightsealing engagement between the wall of casing C and mandrel 39 which will have been inserted through the restricted bore of intermediate portion 13 and will act thereon to intensify the outward expansion of sleeve [2. The foregoing operations are generally conventional in all respects "and will be clearly understood by those skilled in the art.

As sleeve [2 is thus compressed and expanded, slips 33 will be forced outwardly thereby into tight gripping engagement with the wall of casing C and, by virtue of their upwardly facing teeth 34, will lock the packer against upward movement relative to casing (I. (See Fig. 2.) At the same time, under the compressive force applied to sleeve l2, garter spring 22 will expand radially with the lower end of the sleeve and will move radially along the upper .face of flange 2| into tight sealing contact with the wall of easing C, to thereby form 'what becomes, in effect, a metal-reinforced resilient seal for the space between the periphery of flange 2| and the wall of easing C. The diameter of the coils forming spring 22 will normally be dimensioned to be somewhat more than twice the width of the annular space between the periphery of flange 2i and the wall of casing C. Accordingly, when garter spring 22 has expanded to the maximum extent permitted by casing C, less than half of its diameter will extend over the outer edge of flange 21 and thereby prevent extrusion of any of the sleeve material into the space between flange 2| and easing C and will thus form a trap for the sleeve material. With this arrangement, it will be seen that the sleeve ma terial will be substantially entirely confined within the annular sealing area defined by the wall of easing C and mandrel 39 and a bottom closure formed by garter spring 22, so that despite the very great pressures often applied to the sleeve by the weight of the operating pipe, and by the column of fluid commonly present in wells, the sleeve material cannot escape from the sealing area and will, therefore, provide maximum sealing efiiciency for the packer. At the same time, the greater the compressive force applied to the sealing sleeve, the tighter will slips 33 be forced into gripping engagement with casing C, and the more positive will become the hold-down action of the slips on the packer. When the packer is to be released in the usual manner by withdrawal of mandrel 39 from the interior of the sleeve, the

resulting contraction of the sleeve will automatically retract slips 33 from their engagement with the casing. The continued upward movement of the sealing stem is then employed in the conven tional manner to effect retraction of slips 25 and permit the entire packer to be withdrawn from the Well.

Figs. '7 to 11, inclusive, illustrate another embodiment of a hold-down slip assembly in accordance with this invention. In this embodiment, the hold-down slip assembly is arranged as a unit separate from the main sealing assembly of the packer but is operable, as in the previous described embodiment, for setting and release by the same operations employed in setting and releasing the main packer structure.

In this embodiment a tubular metallic sleeve 42a is internally threaded at its lower end for connection to threads 2'! of collar 13 in place of seat ring 28 of the previously-described embodiment. Sleeve 42a is counter-bored from its upper end to provide a first internal shoulder 43 adjacent its upper end which tapers downwardly and inwardly and a second flat shoulder 44 adjacent its lower end, the internal diameter of shoulder 44 being somewhat smaller than that ternal diameter 6. Lofshoulder '43 and substantially equal to the :in-

of collar l3. The wall oi sleeve 42a is provided with a plurality of angularly spaced apertures 45 of generally rectangular shape which are positioned between shoulders 43 and 44. A tubular resilient sleeve 46 is inserted in the bore of sleeve 42a and has a smooth internal bore of substantially the same diameter as that of shoulder 44 and collar l3 so as to be substantially flush therewith. The exterior surface of sleeve 46 is shaped to complement the shape of the inner wall of sleeve 4211, as illustrated in Fig. '7, so that it will fit snugly in the bore of sleeve I2 with its lower end resting on shoulder 44. The length of sleeve 46 is somewhat less than that of the bore of sleeve 42a above shoulder '44 so that its upper end terminates somewhat below the upper edge of sleeve 42a. An annular seat ring 41 is slidably inserted in the upper end of sleeve 42a in compressive trelationship with the upper end of resilient sleeve 46, forming a packing gland for the upper end of sleeve 42a. The bore of seat ring 41 is made substantially flush with that of resilient sleeve 46. A plurality of slip elements 48, having teeth or wickers 49 on their outer faces are installed in the several apertures 45. Slip elements are of the same general configuration as apertures 45 and of slightly smaller dimensions so that they are freely movable radially in apertures 45. In transverse section, slip elements 48 are arcuate in order to fit snugly against the outer surface of resilient sleeve 46 and will normally be cemented to the latter. A pair of guideways 56 are cut in the opposite ends of each of the slip elements 46 and extend from the front faces thereof to a point just short of the rear faces thereof to thereby form oppositely extending lugs 5i on the upper and lower ends of the slip elements. Threaded studs .52 are screwed into the outer wall of sleeve 42 just above and below the ends of the slip elements, so that the heads 53 of the studs will extend into guideways 5i] and form abutments cooperating with lugs 51 to limit the outward movement of slip elements 48 in apertures 45.

As will be seen from Figs. '7 and 8, when the sealing stem is manipulated in the conventional manner to set the packer structure, valve 40 will engage seat ring 41 and will apply the weight of the operating pipe to the upper end of resilient sleeve 46. The pressure will be transmitted through the latter to set the .main slips 25 (Figs. 1 and 2) and compress sealing sleeve l2 in the usual manner to form the desired seal between the well casing C and mandrel 39. At the same time, resilient sleeve 46 will be compressed, and being confined against inward expansion by mandrel 39 and against longitudinal expansion by shoulder 44. sleeve 46 can only expand radially outwardly through apertures .45. This expansion will force slip elements 48 outwardly into tight wall gripping engagement with casing C. When slip elements 48 have been thus engaged with the casing, an upwardly directed pressure against the bottom of the packer structure will be opposed by the weight of the operating string on resilient sleeve 46 and will only serve to increase the compression on the latter with the result that slip elements 48 will be forced even more tightly against casing C and thereby efiectively resist any tendency of the packer structure to be forced upwardly in the casing. In this embodiment the lower end of sealing sleeve 12 may be provided with garter spring 22, as in the previouslydescribed embodiment, to perform the functions previously described. Release or the hold-down slips and the main packer structure will be effected by the same conventional operations previously described.

It will be understood that various alterations and changes may be made in the details of the exemplary structures herein described without departing from the scope of the appended claims but within the spirit of this invention.

What we claim and desire to secure by Letters Patent is:

1. In. well packers, a supporting base adapted to anchored to the wall 02 a well casing against downward movement therein, a hold-down slip assembly mounted on said base, comprising, a resilient sleeve member supported at its lower end by said base and radially expandible by axial compression thereof against said base, a compression. member slidable through the bore of sleeve member, laterally extending external abutment means mounted on said compression member and movable therewith into axial engagement with the upper end of said sleeve member, to axially compress and radially expand saic sleeve member, and a plurality of toothed. slip elements circumferentially arranged on and secured to the periphery of said sleeve member movable into and out of gripping engagement with said well casing coincident with the radial expansion and contraction of said sleeve member.

2. In well packers, a supporting base adapted to be anchored to the wall oi a well casing against downward movement therein, a hold-down slip assembly mounted on said base, comprising, a resilient sleeve member supported at its lower end by said base and radially expandible by axial compression thereof against said base into sealing engagement with said well casing, a compression member axially slida'ole through the bore of said sleeve member, laterally extending external abutment means mounted on said compression member and movable therewith into axial engagement with the upper end of said sleeve member, to axially compress and radially expand said sleeve member, and a segmental metallic casing-gripping element circurniercntially disposed on and secured to the periphery of said sleeve member, said element being radially expandible and contractible into and out of gripping engagement with said casing coincident with the corresponding movements of said sleeve member.

3. in well packers, a supporting base adapted to be anchored to the wall or a well casing against downward movement therein, a hold-down slip ass nibly mounted on said base, comprising, a resilient sleeve member supported at its lower end by said base and radially expandible by axial compression thereof against said base into scaling engagement with said well casing, compression mean axially engageable with the up per end of sleeve member, to axially compress and radially expand said sleeve member, a segmental metallic casing-gripping element circumferentially disposed on and secured to the periphery of said sleeve member, said element being radially expandible and contractible into and out of gripping engagement with said casing coincident with the corresponding movements of said sleeve member, and a resilient radially expandible ring-shaped metallic retaining element circumferentially embedded in the lower end of said sleeve member.

4. In well packers including a supporting base adapted to be anchored in a well casing against downward movement therein, a hold-down slip assembly, comprising, a resilient sleeve member supported by said base and radially expandible by axial compression thereof against said base into scaling engagement with said well casing, a metallic collar mounted on the upper end of said sleeve member and axially movable therewith, and a segmental metallic casing-gripping element circumferentially arranged on the periphery of said sleeve member having radially hinged connection to said collar, said element being radially expandible and contractible into and out of gripping engagement with said casing 00- incident with the corresponding movements of said sleeve member.

5. In well packers including a supporting base adapted to be anchored in a well casing against downward movement therein, a hold-down slip assembly, comprising, a resilient sleeve member supported by said base and radially expandible by axial compression thereoi against said base into sealing engagement with said well casing, a metallic collar mounted on the upper end of said sleeve member and axially movable therewith, a segmental metallic casing-gripping element circumierentially arranged on the periphery of said sleeve member having radially hinged connections to said collar, said element being radially expandible and contractible into and. out of gripping engagement with said casing coincident with the corresponding movements of said sleeve member, and a resilient radially expandible ringshaped metallic retaining element circumferentially embedded in the lower end of said sleeve member.

6. A hold-down slip assembly for well packers, comprising, a generally tubular resilient sleeve member radially expandible by axial compression thereof, a metallic collar carried by the upper end of said sleeve member and axial movable therewith, and a plurality of metallic casing gripping elements circumferentially disposed on the periphery of said sleeve member having radially hinged connection to said collar, said elements being radially expandible and contractible coincident with the corresponding movements of said sleeve member.

7. A hold-down slip assembly for well packers, comprising, a generally tubular resilient sleeve member radially expandible by axial compression thereof, a metallic collar carried by the upper end of said sleeve member and axially movable therewith, a plurality of metallic casing gripping elements circumferentially disposed on the periphery of said sleeve member having radially hinged connection to said collar, said elements being radially expandible and contractible coincident with the corresponding movements of said sleeve member, and a resilient radially expandible ring-shaped metallic retaining element circuinferentially embedded in the lower end of said sleeve member.

8. A hold-down slip assembly for well packers, comprising, a generally tubular resilient sleeve member radially expandible by axial compression thereof, upper and lower metallic collars carried by the opposite ends of said sleeve member, the upper one of said collar members being axially movable with said sleeve member, a plurality of metallic casing-gripping elements circumferentially disposed on the periphery of said sleeve member having radially hinged connection to the upper one of said collars, an annular flange on the exterior of the lower one of said collars forming a base for the lower end of said sleeve member, and a resilient radially expandible ring-shaped metallic retaining element circumferentially embedded in the lower end of said sleeve member contiguous to said flange, said casing gripping elements and said reinforcing element being radially expandible and contractible coincident with the movements of said sleeve member.

CICERO 0. BROWN.

FLOYD L. SCOTT, JR.

0 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Spang Nov. 15, 1938 Strom Mar. 19, 1940 Began Apr. 9, 1940 Bendeler et a1. Feb. 4, 1941 Ferris July 4, 1944 Fitzpatrick Aug. 22, 1944 Baker Mar. 6, 1945 Baker Apr. 3, 1945

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