US2990884A

US2990884A - Internal abrading scratcher

Info

Publication number: US2990884A
Application number: US7834A
Authority: US
Inventors: John A Hall; Elmer D Hall
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-02-10
Filing date: 1960-02-10
Publication date: 1961-07-04
Anticipated expiration: 1978-07-04

Description

July 4, 1961 J. A. HALL ET AL INTERNAL ABRADING SCRATCI-IER Original Filed Oct. 10, 1955 4 Sheets-Sheet 1 INVENTOR5. Jo/m ,4. Ha 22 E/mefl 0. Hfl

. TTORNEK July 4, 1961 J, HALL ET AL 2,990,884

INTERNAL ABRADING SCRATCHER Ori inal Filed Oct. 10, 1955 4 Sheets-Sheet 2 INVENTORS. 30 Job/7 4. Ha E/me/ I. Ha

July 4, 1961 J. A. HALL ETAL INTERNAL ABRADING SCRATCHER Original Filed Oct. 10, 1955 INVENTORE. .Ja/m ,4. //fl f/me/ 0 #44/ TORNEY.

July 4, 1961 ET AL 2,990,884

INTERNAL ABRADING SCRATCHER Original Filed Oct. 10, 1955 4 Sheets-Sheet 4 INVENTORS. -/0h/7 4. Hal/ BY E/mefl D. a

A ORNEY.

United States Patent "O 1955. This application Feb. 10, 1960, Ser. No. 7,834

, Claims. (Cl. 166 173) This invention relates to abrading devices for mounting on the casing of oil wells and refers more particularly'rto such a device having internal abrading means mounted therein whereby, during reciprocation of the casing in the bore hole of an oil well during the conditioning or cementing of the oil well, said internal abrading means operate to clean the outside of the casingof any residues or aggregates of mud or cement collecting thereon.

This application is a continuation of application Ser. No. 539,446, filed October 10, 1955 for Internal Abrading Scratcher, now forfeited.

In the conditioning and cementing of oil wells, it is important to have the well bore annulus surrounding the casing as free as possible of obstructions and restrictions in order to obtain readily fiowablestreams of mud and cement. A very important factor which often contributes to restriction of the annulus is the tendency of the mud and cement to adhere not only to the well wall but also to the exterior of the casing. As a result thereof, aggregation and collectingof mud occurs not only on the .well wall extending inwardly toward the center of the well bore but also on the outer surface of the casing extending out waitll'y therefrom toward the well wall. Obviously, the obstructions thus formed in the annulus interfere seriously with the rate of flow and prevent free circulation of both the mud and cement in the conditioning and cementing of oil wells. v

It becomes a primary object, therefore, in the conditioning and cementing of oil wells to overcomethe agg'regation and collection of mud on both the casing and well wall in so far as is possible. To achieve this desired result, efforts are made to simultaneously abrade the well wall and scrape the exterior of the casing during the conditioning of the well and during the cementing cycle. In a preferred arrangement for practicing such a process, there is installed on the well casing at longitudinally spaced intervals a plurality of elements (stop lugs or abrading members) which are substantially fixed in post tion on the casing. Between the lugs or abrading members, the latter of which serve to abrade the well wall during reciprocation of the casing in the well bore, there are mounted scraping collars which encircle the casing and are free to slide longitudinally between the fixed elements or between the fixed elements and the pipe joints, whichever the case may be. These collars have wallengaging fingers which serve to hold them stationary during reciprocation of the casing, thus resulting in a continual cleaning of mud and cement from the exterior of the casing throughout the length of the zone to be conditioned or cemented. It should be noted that abrasion of the well wall by the wires of the abrading collars freely slidable on the casing is only effected during reciprocation of the casing when the bands or collars are abutted by the fixed elements or pipe joints approachin'g the extremities of the up and down strokes of the casing.

Such above mentioned freely sliding scraping members that are conventionally used in the conditioning and cementing of oil wells are supposed to clean the pipe be tween their limiting boundaries in the process of reciprocation but, as there is necessarily a gap between the internal diameter of the scratcher or scraping member and the external diameter of the pipe to permit rotation of the s'cratcher on the pipe when the direction ofrecipro} cation changes (to protect the scratcher wires) and to 2 permit the sliding action of the scraping members on the casing, a filtn' of mud and/ or cement generally remains on the external surface of the casing despite the action of the conventional sliding scraping members which greatly lessens the eifectiveness 'of the conditioning and cementing procedures and also greatly affects the integrity of the cement to pipe bond.

Therefore, an object of the present invention is to pro; vide a casing cleaning or abrdaing member which wil'l eifectively clean the casing of the mud and cement residues which would have gathered thereon during conditioning and cementing procedures in spite of the action of conventional sliding scratching or abrading means on the external casing surface during reciprocation of the pipe in the well. V

Anotherobject of the present invention is to provide casing cleaning scratchers or abrading members slidable on the external surface of a well casing which will effectively clean off residues of mud and cement and casing scale, casing resin or protective coating from the external surface of the casing, which are readily mountable on the casing and which possess internal abrading means which are sufficiently rugged in construction to stand the extreme conditions of wear imposed by well bore condi tions and reciprocation of the pipe and which are easily and conveniently mounted in conventional well bore abrading means. v V i Still another object of the present invention is to provide an internal abrading member for mounting an oil well pipe, which abrading member may be employed itself to scrape the external surface of the well bore casing during the cementing or conditioning processes or which may be attached to conventional external abradiiig means to' properly condition the pipe casing.

Other and further objects of the invention will appear in the course of the following description.

In the drawings, which form a part of the instant specification and which are to be read in conjunctiontherewith, embodiments of the invention are shown and, in the various views, like numerals are used to indicate like parts;

FIG. 1 is a perspective view of a well bore scratching device embodying a preferred form of the invention.

FIG. 2 is a fragmentary internalview of the preferred form of the invention shown in FIG. 1.

FIG. 3 is a view taken along the lines 3-3 of FIG. 2 in the direction of the arrows.

FIG. 4 is a view similar to that of FIG. 2 which shows another modification of the invention,

FIG. 5 is a view taken along the lines 5-''5 of FIG. 4 in the direction of the arrows.

FIG. 6 is a view similar to those of FIG. 4 and FIG, 2 showing another modification of the invention.

FIG. 7 is a view taken along the lines 7--7 of FIG. 6 in the direction of the arrows.

FIG. 8 is a view similar to those of FIGS. 2, 4 and 6, showing another modification of the invention,

FIG. 9 is a view taken along the lines 9-9 of FIG. 8 in the direction of the arrows.

FIG. 10 is a view taken' along the lines 10 -10 of FIG. 9 in the direction of the arrows V FIG. 11 is a view similar to those of FIGS. 2., 4, 6 and 8 showing another modification or the invention.

FIG. 12 is' a view taken along the lines 12-12 of FIG. 11 in the direction of the arrows. i,

FIG. 13 is a fragmentary internal view of a' pipe en circling band embodying another modification of the iiivention. p

FIG. 14 is a view taken along the lines 14--14 of FIG. 13.

FIG. 15 is a dragmeiitary internal view of a band simi lar to that shown in FIG. 13 illustrating another riiddifi cation of the invention;

FIG. 16 is a fragmentary internal view of a pipe encircling band embodying another modification of the invention.

FIG. 17 is a view taken along the lines 17-17 of FIG. .15 in the direction of the arrows.

FIG. 18 is a fragmentary internal view of a pipe encircling band embodying yet another modification of the invention.

' FIG. 19 is a view taken along the lines 19-19 of FIG. '18 in thedirection of the arrows.

, FIG. 20 is a fragmentary internal view of a pipe eneircling band embodying another modification of the invention.

FIG. 21 is a view taken along the lines 2121 of FIG. 20 in the direction of the arrows.

The invention broadly conceived comprises a pipe cleaning element for mounting on an oil well pipe or casing which comprises a casing engirdling band having an internal diameter greater than the outer diameter of the pipe orcasing, the edges of the band being inwardly angled to define the desired internal diameter of the band edges relative the casing and having internal abrading means positioned between the edges of the band operative to contact the external surface of the casing as the casing reciprocates in the well bore whereby to clean the casing of any residues of mud or cement which may aggregate thereon during the well conditioning or cementing process. Such a pipe cleaning element may or may not also include external well bore abrading means mounted thereon or attached thereto in addition to the internal abrading means which operate to scrape and clean the external surface of the pipe. It is contemplated that all of the following external abrading elements may be employed with the inventive internal abrading elements: free ends of scratchers, free ends of baskets, closed outer edges of cable loop scratchers and the bows or bodies of any type centralizer. Referring first to FIGS. 1 through 12, the essentially conventional structure of the conventional well bore scratcher which is to be employed in modifications of the invention illustrated therein will be described first, together with its conventional mode of operation in the well bore. After this, the invention as employed in such a scratcher will be described and its mode of operation in the well conditioning and well cementing processes.

The scratchers are preferably in the form of collar supports to which are flexibly attached abrading wires which extend nonradially from the support. The collars of the scratchers are mounted rotatively and with a limited axial movement on the casing or pipeto permit easy reversal upon reciprocation of the casing in the well. Referring to FIGS. 1 through 12 and particularly to FIG. 1, at 20 is shown a collar support or band which is circular in form, being conventionally fabricated by pressing from a strip of sheet metal and welding together its ends. The edges 20a of said band are inwardly angled to define the desired internal diameter of the scratcher. At intervals around the circumference of the collar are lanced out (by punching) tabs or tongues 21 which serve as the gripping or anchoring members for the abrading wires. The wire or cable abrading elements, which are in the form of tines or whiskers, or loops, extend from the collar in two circumferential rows; the wires in the upper row being designated by the numeral 22a and the tines or whiskers in the lower row designated by the letter 22b. Interposed in the wires at the points of projection from the collar are coils 22c. Cross-over sections of the wires between the coils 220 which, in the construction shown, lies within the collar, are designated 22d. These cross-over sections are gripped beneath the anchoring tabs or tongues 21. Holes 23 are punched in the collar and located so the coils formed in the wires extend through the holes.

In conventional well wall abrading operation, a plurality of the scratchers are mounted upon the exterior of a pipe or casing (not shown). The scratcher collars have a slightly greater internal diameter than the external 4 diameter of the pipe on which they are mounted. Lugs, stops or fixed well wall abrading elements are welded to the pipe above and below the collars to permit a limited longitudinal movement of the pipe within the collars and free rotation of the collars upon the pipe. The interval at which the scratchers are positioned along the pipe is usually governed by the length of the stroke of reciprocation given the pipe during the conditioning operation.

As the pipe is run into the well, there is an annular space'between the pipe and Well bore having a width considerably less than the distance that the wires extend from the exterior of the collar. As a consequence, as the easing or pipe is run into the well bore, the wires frictionally engage the wall of the well and the abrading elements or tines drag or are inclined upwardly as the casing is moved downwardly into the well. When the casing or pipe arrives at the location where it is to be set or where the well wall is to be cleaned of mud cake, the pipe is reciprocated in the well bore for a distance upwardly and downwardly corresponding substantially to the distance between the scratchers. Thus, the well wall is abraded by the scratcher wires throughout the zone to be conditioned. During the down stroke the stops above the collars of the scratchers contact the top rim of the collar until the direction of movement of the pipe is reversed. Upon reversal of the direction of movement of the pipe or as the up stroke commences, the pipe passes through the collars until the lugs below the collar contact the lower rim of the collars and the wires or abrading elements pivot at their ends in the well wall causing the collars to rise above the end of the wires frictionally contacting the well wall.

FIGS. 1, 2 and 3 illustrate a firstforrn of the invention. In this form, the internal abrading means positioned between the edges of the band comprise a plurality of vanes 24 mounted on the internal surface of band 20 and spaced thereon relative one another. Vanes 24 have bases 24a welded or attached to the band by rivets 25. The edges of the vanes are preferably rounded for safety and for ease of mounting the scratcher on the casing. Vanes 24 preferably are divided centrally to permit motion of residues through the opening formed by the division. Vanes 24 are preferably positioned with their edges running essentially axial to the axes of the scratcher and the casing. The internal diameter of opposed vanes is preferably less than that of the internal diameter of the collar edges and the external diameter of the easing whereby to force the vanes to engage the casing surface at all times. The vanes 24 are preferably formed of metal or material of sufficient resilience whereby the vanes may change their angle of contact with the pipe when the scratcher changes its direction of rotation on the pipe during the reciprocation of the latter in the well bore. The vanes 24 may be angled slightly off the axial line of the casing and the scratcher band. Such angling permits a slightly greater cleaning effect in purely vertical movement of the casing within the scratcher. FIGS. 4 and 5 illustrate another modification of the invention. In this modification, the internal abrading means positioned between the edges of the band comprise a plurality of abrading wires 26 mounted internally of said band and extending inwardly thereof. The abrading wires 26 are effective to contact the external surface of the pipe during reciprocation of the pipe and clean the aforementioned residues from the pipe. The wires 26, as employed in the scratcher structure of FIG. 4, are shown having cross-over portions 260 engaged by tabs 21 which also serve to confine the cross-over portions 22d of the external abrading whiskers 22a and 22b. The internal abrading wires 26 are preferably of such inwardly extending length that the internal diameter between 180 opposing wire ends is less than the outer diameter of the casing on which the scratcher is mounted and the internal diameter of the collar edges 20a whereby the wires 16a will engage the casing surface at all times. Preferably, also, wires 26 are of such resiliency that they will reverse their angle of abutment with the pipe when the scratcher reverses its direction of rotation on the pipe during reciprocation of the casing in the well bore.

FIGS. 6 and 7 illustrate another modification of the invention in that internally directed wires 27 are formed with a coil 28 at the base thereof whereby to increase the give and resiliency of the wire when the scratcher reverses its direction of rotation on the casing during reciprocation of the latter. As shown in FIGS. 6 and 7, in this modification wires 27 having coils 28 are preferably fixedly attached to studs 29 mounted on the internal surface of the band 20. This mounting is independent of the tabs 21 and the external abrading wires 22a and 22b. It should be noted, however, that coils could be inserted in the internally abrading wires 26 of the previous modification (FIGS. 4 and 5) should it be desired.

FIGS. 8, 9 and 10, in another modification of the invention, illustrate inwardly extending abrading wires 30 similar in character to those shown in FIGS. 4, 5, 6 and 7, wires 30 having coils 3 1 at the base thereof to increase the resiliency of the wires when the scratcher changes its direction of rotation on the pipe during reciprocation of the latter, but in this instance the coils being inserted or screwed into the larger coils 22c of the external abrading whiskers of wires 22a and 22b. In such a mounting it is preferable that the coils 31 be of an external diameter essentially equal to, or slightly greater than the internal diameter of coils 22c and the coils 31 of essentially equal depth to that of coils 22c.

FIGS. 11 and 12 show another modification of the invention wherein the internal abrading means positioned between the edges of the band comprises a 0 spring 32 positioned internally of said band (and preferably adjacent one inwardly angled edge 20a), spring 32 being fixed at its open ends to said band 20 and having a plurality of internal abrading Wires 33 mounted thereon in such fashion that during the reciprocation of the pipe in the well bore at least one of the ends of each internal abrading wire 33 always contacts the external surface of the pipe. It should be noted that the two ends of the wires 33 extend inwardly at an angle one to the other while the body of the wire is wrapped successively around the C spring to position the Wire thereon. Wires 33, or rather, the inward extensions of said wires, are pref'erably of such length that the internal diameter of 180 op posing ends thereof is less than the outer diameter of the pipe upon which the scratcher is mounted and the internal diameter of the edges 20a. The wires 33 may be loosely mounted upon the 0 spring 32 so that they may slide around the periphery thereof, or said wires may be fixed to the 0 spring at regular intervals there* along. It is also contemplated to employ a pair of C springs 32, each of which will have a plurality of internal abrading wires 33 thereon. One of each of said C springs would preferably be positioned adjacent each inwardly angled edge 20a of the scratcher band 20.

FIGS. 13, 14 and illustrate, in other modifications of the invention, a pipe cleaning element suitable for use with any of the aforementioned internal abrading means and contemplated for use therewith, which may be employed either separately mounted by itself on an oil well casing to scrape the exterior thereof or attached to the edge of a conventional scratcher similar to the type shown shown FIG. 1. The element comprises a pipe encircling band 34 having an internal diameter greater than the outer diameter of the casing on which it is to be mounted, the edges 34a of said band inwardly angled whereby to define the desired internal diameter of the band edges relative the pipe. Means to contact the external surface of the pipe as the pipe reciprocates in the. well bore to clean the pipe of any residues aggregating, thereon are positioned between the edges of the band; FIGS. 13, 14 and 15 illustrate. such an internal abrading means which comprises a circumferential flange having an internal diameter less than that of the inwardly angled edges 34a and also less than the outer diameter of the pipe on which the element 34 is positioned. FIGS. 13 and 14 show the flange as a segmented metallic strip 35 having base 36 attached to band 34 by welds 35a or other suitable conventional means adaptable to reverse its angle to the pipe when the element reverses its direction of movement on the pipe. FIG. 15 shows the circumferential flange as an edged band 37 or resilient yieldable material, such as rubber, which will also readily reverse its angle to the pipe when the pipe reverses its direction of movement in the element.

The three forms of the invention shown in FIGS. 16-17, l8-l9 and 20-21, respectively, are ones which require a collar or band of greater width than the collars of the modifications previously described. All other features of the collar or band are the same so the extra width portions are not separately numbered and should be regarded merely as extensions of collar or band 20 between the inwardly formed edges 20a.

FIGS. 16 and 17 illustrate a modification of the invention wherein horizontal cables 38 are gathered by studs 39 to form in cross section a plurality of cable loops having an internal diameter between diametrically opposed loops slightly less than the outer diameter of the casing on which the internal abrading band Cable loops 38'move back and forth over the external surface of the casing as the pipe is reciprocated in the well bore and also abrade the pipe radially during rotation of the element on the pipe. If, as is shown in the drawings, two or more horizontal cables 38 are employed, the studs 39 are preferably staggered relative one another from cable to cable to present the fullest possible cross-sectional overlap of the cable loops.

FIGS. 18 and 19 show a modification of the invention wherein a plurality of small wire cables or wire loops 40 are fixed to the internal surface of the scratcher band or ring by studs 41. The free loops 40 are attached to the internal surface of the abrading ring in such a manner that they angle inwardly therefrom and retain this angular position by their natural springiness or resilience. The loops 40 present, as may be seen in the dnawings, an abrading surface for both reciprocal movement of the casing in the well bore and rotatory motion of the scratcher thereon. When the scratcher band changes its direction of rotation on the casing as the direction of reciprocation of casing is changed, the wire loops 49 may bend back and forth over the studs 41.

FIGS. 20 and 21 illustrate a modification of the invention wherein a cable 42 runs transversely back and forth over the inner surface of the scratcher band or ring and is gathered into inwardly extending loops by studs 43 formed on the internal surface of the abrading band. This modification presents an abrading surface for both rota tory motion of the scratcher band on the casing and recip rocal motion of the casing in the Well bore and the cabl loops may shift angle back and forth relative the surface ofthe casing as the scratcher band changes its direction of rotation on the casing.

In operation, a pipe cleaning element having an" internal abrading means as described in the foregoing description, is mounted on the exterior of an oil well pipe or casing. The pipe cleaning element may comprise either a scratcher, such as is illustrated in FIGS. 1 through 12-,- said scratcher having internal abrading means therein also as shown in FIGS. 1 through 12, or, it may com prise a pipe cleaning element as shown in FIGS. l3, l4 and 15, having only internal abrading elements therewith, said pipe cleaning element being mounted by itself on the casing between free sliding scratchers or between free sliding centralizers or within a free sliding centralizer or attached to the edge of a conventional scratcher similar to that shown in FIG. '1. Lugs, stops or fixed-well wall abrading elements are welded to the pipe aboveand below the pipe cleaning elements to permit'a limited longitudinal movement of the pipe therethrough and free rotation of the elements upon the pipe. The interval at which the pipe cleaning elements are positioned along the pipe is preferably governed by the length of the stroke of recip rocation given the pipe during the conditioning operation. When the casing or pipe has been run into the well and arrives at the location where it is to be set or where the well wall is to be cleaned of mud-cake, the pipe is reciprocated in the well bore for a distance upwardly and downwardly corresponding substantially to the distance between the pipe cleaning elements, or even twice or three times the distance between the elements. The pipe cleaning elements are free to slide longitudinally between the fixed elements or between the fixed elements and the pipe joints. The wall engaging fingers or external abrading means on the elements or on the scratchers attached to the elements serve to hold the pipe cleaning elements stationary relative to the Well Wall during reciprocation of the casing, thus resulting in a continual cleaning of mud and cement from the exterior of the casing throughout the length of the pipe having the pipe cleaning elements mounted thereon. The well wall itself is abraded by the external abrading means of the scratchers which are freely slidable on the casing only when the pipe cleaning el ments are abutted by the fixed elements or pipe joints approaching the extremities of the up and down strokes of the casing.

Referring more specifically to the operation of the individual casing cleaning abrading means, the vanes of the embodiment of the invention shown in FIGS. 1-3 cut and scrape the residues from the exterior surface of the casing as the pipe moves therethrough. The freed debris can pass through the openings between the vane halves and the vanes themselves are free to reverse their angle to the pipe if the scratcher reverses its direction of rotation thereon as the direction of reciprocation of the pipe in the well changes.

In the modifications of the invention employing internally abrading wires shown in FIGS. 4 through 12, the reciprocation of the casing in the well bore causes the free edges or ends of the wires to scrape and score the outside of the casing, thus cutting and scraping any residues thereon free of the casing. The coils at the base of the inwardly extending wires shown in the modifications of FIGS. 6 through 10 permit greater freedom of motion of the wires, especially during any changes of direction of rotation of the scratchers on the casing due to changes of direction of reciprocation of the pipe in the well bore. The wires of FIGS. 11 and 12 find extra resiliency in their coiled portions wrapped around the C spring 32. In this modification, only one end of each wire 35 contacts the casing surface at any one time.

The modifications of the invention shown in Figs. 13 through 15 do not employ external abrading wires on the pipe cleaning element. Such a pipe cleaning element is motivated in its travel along the pipe by an attachment to a conventional scraper means or scratcher similar to that shown in Fig. 1, but without internal abrading means therein or by the action of such a conventional scratcher which is positioned on each side thereof to freely move along the casing therewith during reciprocation of the pipe. It is contemplated that such conventional scratcher means which serve to drive the modifications of Figs. 13 through 16 along the pipe may also employ therein internal abrading means of the types shown in Figs. 1 through 15. The pipe scraping means of Figs. l3, l4, and 15 comprise circular resilient flanges of segmented metal or rubber which operate to wipe the external surface of the casing free of any residues aggregating thereon and these scraping or wiping means are of a strength and resiliency that they will both effectively wipe the external surface of the casing and freely reverse their angle of contact with the pipe when the pipe cleaning element reverses its direction of motion on the casing. Any rotational motion of such a pipe cleaning element permits the casing cleaning flange to bite into the casing residues and thus aids in cleaning the casing surface.

The modifications of the invention shown in Figs. 16 through 21 illustrate internal abrading means of closed loops of cable or wire without free ends contacting the casing to be scraped. These closed loops completely encircle the inside surface of the scraper band and, between diametrically opposed loops, have an internal diameter less than the outer diameter of the casing. The reciprocation of the casing with these closed loop-type of internal abrading means cleans the residues therefrom which can then pass freely through the abrading loops without clogging. The loops themselves are free to reverse their angle to the pipe if the band reverses its direction of rotation thereon as direction of reciprocation of the pipe in the well changes.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim:

1. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said band between said edges, whereby to space said hand between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom adapted to engage the well bore wall at a plurality of circurnferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through the band during at least said portions of said reciprocation, and a plurality of second means of greater resilience than said first means connected to said band at a plurality of circumferentially spaced points and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced points and clean material therefrom in abrading action as the pipe moves through said band during reciprocation thereof in the well bore, the length of each said resilient means connected to said band and extending inwardly thereof substantially greater than the distance said band is spaced from the outer surface of said pipe whereby each said resilient means will continuously contact said pipe at any position of the band thereon.

2. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said band between said edges, whereby to space said band between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocationbf the pipe whereby to permit the pipe to move therethrough during at least-said portions of said reciprocation, and a plurality of wires of greater resilience than said first means connected to said band at circum-ferentially'spaced points thereon and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced points and clean material therefrom in abrading action as the'pipe moves through said banddu-rin'g reciprocation thereof in the well bore, the length of each resilient wire connected to said band and extending inwardly thereof substantially greater than the distance said band is spaced from said pipe whereby said wires will each continuously contact said pipe at any position of the band thereon.

3. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upperand lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said band between saidedges, whereby to space said hand between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of paired openings formed in said band between said edges spacedcircumferentially around said band, one of each said pair of openings positioned above the other of said pair (if-openings on said band, a pairof wires positioned internally of said band between the openings of each said pair of openings, means connected to said band attaching said wires to said band, the free ends of a first oneof said pair of wires extending outwardly through said openings and peripherally of said band whereby to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through said band and wires during at least portions of said reciprocation, the free ends of the second of said pair of Wires extending inwardly of said band and adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced points and clean material therefrom in abrading action as the pipe moves through said band during reciprocation of the pipe in the well bore, the second of said pair of wires of greater resiliency than the first of said pair, the inward extension of said free ends of the second of said pair of wires of substantially greater distance than the distance the band is spaced from the pipe whereby said free ends will continuously contact said pipe at any position of the band thereon.

4. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said hand between said edges, whereby to space said band between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom adapted to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through the hand during at least said portions of said reciprocation, and second means of greater resilience than said first means connected to said band at circumferentially spaced positions and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced zones and clean material therefrom in abrading action as the pipe moves through said band during reciprocation thereof in the well bore, the length of said resilient means connected to said band and extending inwardly thereof being substantially T9 greater than the distance saidband is spaced from the outer surface of said pipe whereby said resilient means will continuously eontact'said pipe at any'position of the band thereon.

5. A pipe cleaning element for mounting on a oil well pipe, the latter vertically 'reciprocable in a well bore,- comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of the hand between said edges, whereby to space said band between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a first plurality of wires connected to said band and extending peripherally past the outer surface thereof adapted to engage the well bore wall at a plurality of points circumferentially spaced relative to said band, whereby to'substan'tiall'y fix the position of said band in said well bore during at least portions of the reciprocation of the pipe in the well bore to permit the pipe to move through the band and first plurality of wires during at least said portions of said reciprocation, said peripherally extending wires including coils adjacent the connection thereof to said band, a second plurality of wires of greater resilience than said first plurality each connected to one of said first plurality of Wires and extending inwardly of said band and adapted to continuously engage the'pipe outer surface at a plurality of circumferentially spaced points and clean material therefrom in abrading action as the pipe moves through said hand during reciprocation of the pipe in the well bore, said second plurality of wires including coils at the connection thereof to said first plurality of wires, the coils of said second plurality of wires fixedly received within the coils of the first plurality of wires, the length of each wire in said second plurality extending inwardly of the band being substantially greater than the distance the band is spaced from said pipe whereby each said wire will continuously contact said pipe at any position of the band thereon.

6. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a Well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said band between said edges, whereby to space said hand between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom adapted to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through the band during at least said portions of said reciprocation, a plurality of vanes of greater resilience than said first means connected to said band at a plurality of circumferentially spaced positions and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced positions and clean material therefrom in abrading action as the pipe moves through said hand during reciprocation thereof in the well bore, the inward extension of each said resilient vane connected to said band and extending inwardly thereof substantially greater than the distance said band is spaced from the outer surface of said pipe whereby each said resilient vane will continuously contact said pipe at any position of the band thereon.

7. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameterv of said band between said edges whereby to space said hand between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom adapted to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through the band during at least said portions of said reciprocation, and a plurality of closed loops of resilient material of greater resilience than said first means connected to said band at a plurality of circumferentially spaced positions and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced positions and clean material therefrom in abrading action as the pipe moves through the band during reciprocation thereof in the well bore, the inward extension of each said closed loop connected to said band and extending inwardly thereof substantially greater than the distance said band is spaced from the outer surface of said pipe whereby each said closed loop will continuously contact said pipe at any position of the band thereon.

8. Apparatus as in claim 7 wherein said plurality of closed loops comprises segments of an elongate cable having spaced portions thereof attached to the inner surface of the band.

9. Apparatus as in claim 8 wherein said cable zigzags along the internal surface of the band in angular disposition relative to the vertical axis of the band,

10. A pipe cleaning element for mounting on an oil well pipe, the latter vertically reciprocable in a well bore, comprising a pipe encircling band of internal diameter greater than the outer diameter of the pipe, the upper and lower edges of said band inwardly angled to a lesser internal diameter than the internal diameter of said band between said edges, whereby to space said band between said edges radially a distance substantially greater than the thickness of said band from the outer surface of said pipe, a plurality of first means connected to said band and extending outwardly therefrom adapted to engage the well bore wall at a plurality of circumferentially spaced points, whereby to substantially fix the position of said band in said well bore during at least portions of the reciprocation of the pipe whereby to permit the pipe to move through the band during at least said portions of said reciprocation, and a circumferential flange of greater resilience than said first means connected to said band at a plurality of circumferentially spaced points and extending inwardly thereof adapted to continuously engage the pipe outer surface at a plurality of circumferentially spaced positions and clean material therefrom in abrading action as the pipe moves through said band during reciprocation thereof in the well bore, the inward extension of said flange connected to said band and extending inwardly thereof substantially greater than the distance the band is spaced from the outer surface of said pipe whereby said circumferential flange continuously contacts said pipe at any position of the band thereon.

References Cited in the file of this patent UNITED STATES PATENTS 2,352,198 Gibson Nov. 4, 1944 2,602,512 Baker July 8, 1952 2,671,515 Hall Mar. 9, 1954 FOREIGN PATENTS 611,887 Great Britain Nov. 4, 1948