US1840747A - Pipe guide - Google Patents

Description

Jan. 12, 1932. J. G. SNIFFIN ET AL PIPE GUIDE Filed Jan. 16, 1930 Patented 1dan. 12, 1932 i UNITED STATES PATENT oEFIcE JOHN G. SNIFFIN, F MAYWOOD, AND PETER HAMMER, OF BREA, CALIFORNIA PIPE GUIDE Application led January 16, 1930. Serial No. 421,122.

This invention is a guide for centering` pipe, and is particularly applicable to oil field practice for centering casing and perforated pipe so that cement may-be uniformly distributed and perforated pipe may be unilformly spaced from the surrounding well iore.

It is an object of the invention to mount a normally contracted guide on a string of casing so that i-t may be positively expanded to operative position engaging the wall of the bore when the casing has been lowered into the well, thereby centering the casing in the bore and providing a uniform surrounding l5 space for discharge of cement or flow of oil into the casing through usual perforated pipe.

It is a further object of the invention to provide a guide which preferably operative- '0 ly engages the wall of the bore at axially spaced points so as to insure centering of the casing throughout any desired length.

It is a still further object of the invention to adapt the guide for positively limiting 2 lowering of a string of casing into a well so as to position a cementing shoe or the like at any desired level.

It is a still further objectl of the invention to expand the guide by means of a telescopic engagement which is operated by continued lowering of the upper portion of the string of casing after its lower portion has anchored on the bottom of the wellbore, the arrange ment of parts being such as to positively support the string of casing after it has been telescoped for expanding the guide, and the expanded guide preferably having vmeans for locking it against accidental contraction as 'a result of movement of the casing when being stretched, etc.

Further objects of the invention will be readily understood from the following description of the accompanying drawings, in which:

Fig. l'is a side elevation, partly in axial section, showi-ng the guide contracted and adapted forfuse in connection with a cementing shoe.

Fig. 2 is a similar view with the guide expanded to operative position.

Figs. 3 and 4 are transverse sections on the lines 3 3 and 4 4 respectively of Fig. 1.

Fig. 5 is a view similar to Fig. l but showing the guide employed in connection with usual perforated pipe.

The guide may be employed in connection With a string of well casing which is adapted for usual suspension from a draw works (not shown) for lowering the casing string 1into a Well bore, with the casing string comprising usual casing lengths l connected by coupling collars 2, and as illustrated at Fig. 1 preferably having a depending cementing shoe 3; and the guide comprises axially extending arms overlying the casing and adapted for radial expansion so as to engage the Well bore and center the cementing shoe for uniform distribution of cement.

The arms are preferably expanded by movement of the string of casing relative thereto, and for this purpose are mounted on an anchoring means which is adapted to rest on the bottom of the well bore so as to permit lowering of the casing relative to the anchored arms, with the string of casing having means for engaging the arms so as to expand the same. The anchoring means is preferably a length of casing 4 which may have a guide shoe 5 at its lower end, and circumferentially spaced arms 6 project upwardly from casing 4 for free sliding fit in longitudinal grooves 7 of cementing shoe 3, and are connected at their upper ends by a collar 8 which is adapted to rest on an exterior shoulder 9 at the upper end of the cementing shoe. A second set of circumferentially spaced arms 10 are preferably adapted for sliding fit in longitudinal grooves 11 of couling 2, and are connected at their lower 'end y a collar' 12 which is adapted to rest on collar 8, with annular bands 13 preferably connecting the arms 10 at suitable longitudinally spaced points. l The anchor 4 together with arms 6 and collar 8 are preferably formed from an integral length of casing which is suitably cut-out to form the circumferentially spaced arms, and the collar 8 which is a part of this length of casing is split as shown at 14 so that arms 6 may be seated in grooves 7 with the collar seating on shoulder 9, and the collar then welded at its split as shown in Fig. 1. In similar manner a suitable integral length of casing is preferably cut-out to form the circumferentially spaced arms 10 together with their collar 12 and bands 13, and this unitary structure may be operatively mounted on casing 1 wit-h arms 10 projecting upwardly for reception in the cooperating grooves l1 which may be formed in one 0r more of the coupling collars 2, and the casing 1 is then threaded into cementing shoe 3 for assembling the parts.

When lowering the assembled structure into a well the collar 8 rests upon shoulder 9 with the upper end of anchor 4 appreciably spaced below cementing shoe 3 as shown in Fig. l, so that when the anchor strikes the bottom of the well bore continued lowering of the string of casing will telescope shoe 3 relative to arms 6 until the cementing shoe rests upon the open upper end of the anchor as shown in F ig. 2; and by thus telescoping shoe 3 relative to anchored arms 6, the one or more couplings 2 which arms 1 0 overlie, are similarly longitudinally shifted relative to said overlying arms which are supported by their collar 12 resting upon collar 3.

This longitudinal movement of shoe 3 and coupling 2 relative to arms 6-10 is adapted to radially expand the arms so as to engage the surrounding well bore and thereby center the string and thus provide a uniform surrounding space; and for this purpose a longitudinal wedging engagement is provided between grooves 7-11 and the coop- @rating arms 6-10. As an instance of this arrangement the grooves 7-11 may taper to a gradually increasing diameter toward their upper ends, with cooperating wedges 15-16 on arms 6 1() engaging the tapering grooves when the string of casing is lowered relative to the anchored arms.

Vhen the arms have been expanded so as to center the telescoped string of casing which is supported on anchor 4, the parts are preferably locked against accidental release, as for example by providing fingers 17 at the lower ends of wedges 15--16 adapted for automatic engagement in cooperating slots 18 which are formed in the grooves 7-11.

With the string of casing thus centered and anchored in the well bore, it may be cemented in usual manner, the cementing shoe 3 being shown as adapted for axial discharge of cement into anchor 4, from which the cement may discharge through suitable perforations 19, and from which the cement will also discharge through the upwardly cxtending grooves 7 when the cement overflows the anchor. In order to positively direct cement upwardly for discharge from anchor 4 through grooves 7, a perforated baflie 20 may extend across anchor 4 immediately be- 10W the telescoped cementing shoe, so that while a part of the cement will flow through the perforations of the baffle for discharge through openings 19, the major portion of the cement will be directed upwardly by striking the baffle and will thus discharge through grooves 7. The cement is thus uniformly distributed, due to the centering of shoe 3 in the well bore, and the anchor 4 forms a reinforcement in the body of cement which is discharged into the well.

In practice the anchor 4 may be of any predetermined length adapted to position the cementng shoe 3 at any desired level, and depending upon the formation encountered, the arms 6-10 define circumferences of such diameter and bearing such relation to the expanding action of wedges' 15-16 as to expand the arms for predetermined penetration of the surrounding well bore when shoe 3 seats on anchor 4.

The guide may be employed for centering pipe other than merely a cemented string of well casing. Thus for example, and as shown at Fig. 5, the guide may be employed to center a usual string of perforated pipe so as to insure uniform flow of oil through the perforations. For this purpose the anchor 4 is replaced by a usual string of perforated pipe 4a which may be of any desired length and which is adapted to seat on the bottom of the well bore as previously described, with arms 6 projecting upwardly from the perforated pipe and cooperating with a shoe 3 suspended from a string of casing 1, so that when the string of casing is lowered relative to the anchored arms the shoe 3n will expand the arms for centering the perforated pipe as previously described, and will seat in the open upper end of the perforated pipe and thus form a usual casing string having a perforated lower end.

fe have thus provided an extremely practical guide for pipe such as well casing which is adapted to be lowered into a well bore, the guide being normally contracted for unobstructed lowering of the casing but adapted for positive expansion so as to center the casing in the bore, and the invention also providing for locking the guide in operative position and axially supporting the string of casing when it has been lowered to the desired level.

We claim:

1. In combination, a suspended string of Well casing adapted to be lowered in a well bore, a shoe at the lower end of the casing having longitudinal exterior grooves, a supporting shoulder at the upper end of the shoe, an annulus having upstanding spring arms slidably received in the grooves, a collar connecting the upper ends of the spring arms and adapted to rest upon the supporting shoulder for normally suspending the annulus in longitudinally spaced relation below the shoe so that the annulus is adapted to anchor upon the bottom of the well bore when the casing string is lowered in the well, the suspension of the casing string adapting it for lowering relative to the anchored annulus and thereby telescoping4 the shoe relative to the anchored annulus, the shoe having a bore opening through its lower end, the grooves in the shoe convergently tapering toward their lower ends for communication with the bore of the annulus when the shoe is telescoped relative thereto, wedging elements medially of the spring arms cooperating with the tapering grooves for radially bowing the spring arms medially of their length when the shoe is telescoped relative to the anchored annulus, the bowed spring arms being adapted to engage the wall of the well bore for centering the telescoped shoe, and means for locking the shoe in its telescoped position. e

2. In combination, a suspended string of well casing adapted to be lowered in a well bore, a shoe at the lower end of the casing having longitudinal exterior groovesg a supporting shoulder at the upper end of the shoe, an annulus having upstanding spring arms slidably received in the grooves, a collar connecting the upper ends of the spring arms and adapted to rest upon the supporting shoulder for normally suspending the annulus'in longitudinally spaced relation below the shoe so that the annulus is adapted to anchor upon the bottom of the well bore when the casing string is lowered in the well,

the suspension of the casing string adaptingv it for lowering relative to the anchored annulus, the grooves in the shoe convergent-ly tapering toward their lower ends, and wedg-A ing elements medially of the spring arms cooperating with the tapering grooves for radially bowing the spring arms medially of their length when the shoe is lowered relative to the anchored annulus, the bowed spring arms beine' adapted to engage the wall of the well bore igor centering the shoe.

3. In combination, a suspended string of well casing adapted to be lowered in a well bore, a shoe at the lower end of the casing having longitudinal exterior grooves, an annulus having upstanding spring arms slidably received in the grooves and normally suspending the annulus in longitudinally spaced relation below the shoe so that the annulus is adapted to` anchor upon the bottom of the well` bore .when the casing string is lowered in the well, the suspension of the casing string adapting it for lowering relative to the anchored annulus and thereby telescoping the shoe relative to the anchored annulus, the shoe having a bore opening through its lower end, the grooves in the shoe convergently tapering toward their lower ends `for communication with the bore of the annulus when the shoe is telescoped relatlvefor radially expanding the spring arms when 1 the shoe is telescoped relative to the .anchored annulus, the expanded arms being adapted to engage the wall of the well bore for centering thetelescoped shoe.

4. In combination, a suspended string of well casing adapted to be lowered in a well bore, a shoe at the lower end of the casing having longitudinal exterior grooves, an annulus having upstanding spring arms slidably received in the grooves and normally suspending the annulus in longitudinally spaced relation below the shoe so that the annulus is adapted to anchor upon the bottom of the well bore when the casing string is lowered in the well, the suspension o'f the cas- -ing string adapting it for lowering relative to the anchored annulus, the grooves in the shoe convergently tapering toward their lowler ends, and wedging elements on the spring arms cooperating with the tapering grooves for radially expanding the spring arms when the shoe is lowered relative to the anchored annulus, the expanded arms being adapted to engage the Wall of the well bore for centering the shoe.

5. In combination, a suspended string of well casing adapted to be lowered in a well bore, a shoe at the lower end of the casing having longitudinal exterior grooves, an annulus having upstanding spring arms slidably received in the grooves and normally suspending the annulus in longitudinally spaced relation below the shoe so that the annulus is adapted to anchor upon the bottom of the well bore when the casing string is lowered in the well, the suspension of the casshoe convergently tapering toward their lower ends, wedging elements on the spring arms cooperating with the tapering grooves for radially expanding the spring arms when the shoe is lowered relative to the anchored annulus, the expanded arms being adapted to engage the wall of the well bore for centering the shoe, and means for locking the shoe in lowered position with relation to the anchored annulus.

6. In combination, a suspended string of well casing adapted to be lowered in a well bore, the casing string having exterior longitudinal grooves, longitudinal spring arms slidable in the grooves relative to the casing and normally lying iat in the grooves, means for anchoring the spring arms in the well fbore, the 'suspension of the casing string Cil wall of the well bore for centering the casing string.

7. In combination, a suspended string ot well easing adapted to be lowered in a well bore, normally radially retracted guide elements slidably mounted on the casing` and having` an abutment element suspended therefrom so that the abutment element is adapted to anchor upon the bottom of the well bore when the casing string is lowered in the well, the suspension of the casing string adapting it for lowering relative to the anchored abutment elen'ient, and means for radially yexpanding the guide elements by lowering the casing string relative to the anchored abutment element, the radially expamiled guide elements being adapted to engage the wall ot the well bore for centering the casing string.

8. In combination, a suspended string ot well casing adapted to be lowered in a wel! bore, normally radially retracted guide elements slidably mounted on the casing and having an abutment elei'nent suspended therefrom so that the abutn'ient element is adapted to anchor upon the bottom oi" the well bore when the casing string is lowered in the well, the suspension ot the casingr string adapting it for lowering relative to the anchored abutment element, meansfor radially exprriding the guide elements by lowering the easing string relative to the anchored abutment element, the radially expanded guide elements beingadapted to engage the wall ot the well bore for centering` the easing string, and means for locking the casingl string in lowered position with relation to the anchored abutment.

9. In combination, a suspended string ot" for anchoring the guide elements in the well bore, the suspension of the casing adapting it for lowering relative to the anchored guide elements, means for radially expanding the guide elements by lowering the casing string relative to the anchored gude elements, the radially expanded guide elements being adapted to engage the wall ot' the well bore for centering` the casing string, and means tor locking the casing in lowered position with relation to the anchored guide elements.

l0. In combination, a suspended string of well casing adapted to be lowered in a well bore, normally radially retracted guide elements slidably mounted on the casing, a supporting shoulder on the casing, a collar connecting` the upper ends of the guide eleu'ients and adapted to rest upon the supporting` shoulder, means for anchoring the guide elements in the well bore,4 the lsuspension of the casing adapting it for lowering relative to the anchored guide elements, and means for radially expanding the guide elements by lowering the casing string relative to the an- -the anchored annulus and thereby telescoping the casingv relative to the anchored annulus, the grooves in the casing communicating with the bore of the annulus when the casing is telescoped relative thereto, thereby providing tor discharge from the casing into the annulus and thence through the grooves into the surrounding well bore, and means for radially expanding the guide elements by said lowering ot' the casing relative to the anchored annulus.y the radially expanded guide elements bein;r adapted to engage the wall of the well bore tor centering the casing string.

In testimony Whereotl we have alixed our signatures.

.IUI-IN G. SNIFFIN. PETER HAMMER.

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