US2846016A - Stop collar for well casing - Google Patents

Description

Aug. 5, 1958 J. w. E. HANES STOP COLLAR FOR WELL CASING 3 Sheets-Sheet 1 Filed March 19, 1954 INVENTOR: (IQ/145$ EmvEs,

Arroe/vsys.

J. w; E. HANES 2,846,016

STOP COLLAR FOR WELL CASING Aug. 5, 1958 4 3 Sheets-Sheet 2 Filed March 19, 1954 INVENTOR.

0 2M455 WE. HANES,

ATTORNEYS.

1958 J. w. E. HANES 2,846,016

STOP COLLAR FOR WELL CASING Filed March 19, 1954 5 Sheets-Shegt 3 JAMES WE. HAM/E5,

ZZoWM [4' 14 T TOENEYS.

as to hold the strip or band in constricted condition.

STOP COLLAR FOR WELL CASING James W, E. Hanes, Ventura, Califi, assignor, by mesne assignments, to Huntsinger Associates, a joint venture Application March 19, 1954, Serial No. 417,290

2 Claims. (Cl. 28752.04)

This invention relates to equipment for oil well casings, or the like, and particularly to a novel collar construction for limiting movement of casing guiding structures, or the like, or for securing other structures to the exterior of the casing.

In deep well operations, casings of high tensile strength are required. For this purpose, casings made of heattreated steel are commonly provided. Structures such as casing centralizers are carried for movement on the easing bythe aid of stop collars or rings afiixed on the easing. It has been common to weld metal collars in place on the casing for this purpose. Unless very carefully performed, the welding process detrimentally alters the grain structure of the steel casing, resulting in a loss of strength. Furthermore, the welding process alters the uniformity of the grain structure, resulting in localized stresses and cracking.

It is an object of this invention to overcome these difficulties and to ensure against any adverse alteration of the metallurgical properties of high quality casing material. For this purpose, a metal strap or band is constricted about the casing for frictional coupling thereto, a yielding member made of rubber or suitable plastic material being interposed between the band and the casing to provide a firm frictional grip. In one form of the invention, no-vel separable clamp elements mounted on the ends of the band or strip serve to constrict the band or strip as well In other forms of the invention, the band or strip has elements that may be interconnected to hold the band or strip in constricted condition, a novel tool constricting the band or strip to bring the elements into engagement.

It is another object of this invention to make it possible to locate collars, or the like, on the exterior of substantially cylindrical casing structures without altering the structure of the casing per se. It is still another object of this invention to obviate welding of collars, or the like, to the exterior of the casing.

It is yet another object of this invention to provide a simple collar construction or the like that'can be quickly secured to the exterior of a casing by simple operations.

It is another object of this invention to providean improved clamp structure particularly that makes it possible to maintain the size of the collar in sustaining the stresses occasioned by the clamping forces. i

It is another object of this invention to provide a. device ottbis character that conveniently maybe made ans-integral part of the structure intended to becarriedby the casing. i

It is another object of this invention to provide a novel tool for constricting a band about a casing and bringing simple elements at the ends of the band into engaging relationship. N

Thisinvention possesses .nrany other advantages, and has other objects which may be made more clearly appap 'ent fromta consideration of several embodiments ofithe invention. For this purpose, there are shown a few United States Patent 2,846,016 Patented Aug. 5, 1958 forms in the drawings accompanying and forming part of the present specification. These forms will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of the invention is best defined by the appended claims.

Referring to the drawings:

Figure 1 is an elevation of a fragment of an oil well casing in operative position in the well hole, and showing a pair of collars embodying the present invention carried by the casing and cooperating with a casing centralizer;

Fig. 2 is an enlarged elevation, showing a collar incorporating the present invention and in place upon the well casing;

Fig. 3 is a transverse sectional view, taken along-the plane indicated by line 33 of Fig. 2;

Fig. 4 is a further enlarged fragmentary sectional view similar to Fig. 3, but showing the collar in unclamped position;

Fig. 5 is a sectional view, taken along a plane indicated byline 5-5 of'Fig. 4, with some of the parts shown only in phantom lines;

Fig. 6 is a fragmentary broken sectional view, showing the manner in which one of the clampingelements of the collar is rotatably. coupled to its supporting member;

Fig. 7 is. a fragmentary pictorial view of an oil well casing, showing a collar of modified form carried by the casing and cooperating with a. casingcentralizer;

Fig. 8 is a fragmentary pictorial view, showingthe connecting elements carried at the ends of the band;

Figs.- 9, l0 and 11 are plan views, showing the process of constricting. the band about the casing and placing elements atopposite ends of the band in. interlocking relationship by the aid of a collar;

Fig. 12 is a. fragmentary sectional view, taken alon the: plane indicated by line 12-42 of Fig. 11;

Fig. 13 is an enlarged fragmentary sectional view, showing the elements at opposite ends of the band in engaging relationship;

Fig.: 14 is a view-similar to Fig. 7, but showing another modified form of the present invention;

Fig. 15 is 'a fragmentary sectional view, taken on a plane transverse to the wall casing and showing'the device of Fig. 14 in operative position;

Fig. 16 is a sectional view, taken along the plane indicatecl'b'y line 16-l6 of Fig. 15; r

Fig. 17 is a fragmentary planview of still another modified form of the'present invention; and- Fig. 18 is a fragmentary sectional view, taken along the plane indicated by line 1818 of Fig. 17.. 1 r

In the form shown in Figs. 1 to 6, collars 13" are shown that may be used tosupport a structure, such as a casing centralizer, exteriorly of the casing. 1

In Fig. 1, there-isshown a section ofa'well. casing'lfl accommodated in a well; bore 11. A' centralizer 12' is slidable within. limits alongthe exterior of .thecasing section 11% v A pair of collarslfi is secured in longitudinally; spaced relationship along theexterior of thecasing 10'. These collars 13 define the-limits of relative movement; of, the centralizer 12 I along the casing lfl by appropriate -.cooperation with. end rings 14 of the centralizer 12'.

The collars 13- areof special construction whereby theyrnay be. ,afiixedto the casing 10 quite readily v-a nd without performing any welding operations.

. A flexible tubular member 15, madeofsuitablematerial Such as neopreneor the like, is frictionall-y 'heldin place on the casing 10 by being tightl-y constricted-.thera about.

A band 16, made of a thin strip of steel or the like, is accommodated within the tubular member 15. The band 16 has ends 16a and 16b extending beyond corresponding opposite ends 15a and 15b of the tubular member 15. The tubular member 15 is generally rectangular in cross-section, having a through aperture 17 substantially corresponding in shape to the band 16 ac commodated therein.

The tubular member 15 is constricted about the casing 10 by first wrapping the tubular member 15 about the exterior surface of the casing 10, and then by drawing the ends of the band 16 toward each other. This compresses that portion of the tubular member 15 that is in contact with the casing 10. For this purpose and for holding the ends together, a clamp structure is provided. The clamp structure comprises a clamp element 18 and an aperture 19 in which the clamp element engages. The clamp element 18 is carried by the support 20 secured to one end 16a of the band 16. The aperture 19 is located in a support 21 secured to the other end 16b of the band 16. These supports are made of relatively thick metal stock.

The supports 20 and 21 are of arcuate configuration, each having a curvature corresponding substantially to that of the casing 10 with which they cooperate. The support 20 is secured on the inner side of the end 16a such that its arcuate contour generally forms a continuation of the band 16 when the structure is in operative position on the casing 10. Similarly, the support 21 is secured on the inner side of the end 1615. Rivets 22 secure the supports to the band ends. The supports '20 and 21 limit relative longitudinal movement between the band 16 and the tubular member 15, the ends 20a and 21a of the supports forming shoulders for this purpose.

The combined length of the band 16 and the supports 20 and 21 is such with respect to the periphery of the casing 10 that the ends of the supports 20 and 21 overlap each other. The free end of the support 21 is located between the casing 10 and the free end of the other support 20. The clamp element 18 and the aperture 19 are located at the overlying portions of the supports 20 and 21.

The clamp element 18 is mounted for angular movement in the outer support 20 about an axis 24 (Fig. 3) transverse'to the juxtaposed ends of the supports in a manner to be hereinafter more fully described. An inwardly extending eccentric projection 23 is integrally formed with the element 18.

The eccentric projection 23 is received in the clamp aperture 19, and terminates within the confines of the aperture when the parts are in operative position. In order to install the clamp, the ends of the supports 20 and 21 are overlapped and the projection 23 inserted into the aperture 19, with the projection 23 nearest the end of the support 20.

The resilience of the band 16 maintains the outwardmost end wall 19a of the aperture 19 in engagement with the projection 23.

The projection 23 moves from one side of the axis 24 to the other upon rotation of the element 18. Since the end wall 19a of the aperture 19 follows the position of the projection 23, the degree of overlapping of the supports 20 and 21 is increased when'the projection is positioned inwardly from the end of the support 20 to cause constriction of the band 16.

In the position of the clamp element 18 shown in Figs. 2 and 3, the supports 20 and 21 are substantially at their maximum overlapped position in which the tubular member 16 is tightly constricted about the casing 10.

When the clamp element 18 is moved to the opposite angular position about the axis 24 (Figs. 4 and the supports 20 and 21 are in their minimum overlapped '4' position. The tubular member 15 is substantially upon the casing 10.

The clamping projection 23 is generally rectangular in configuration, with its edges rounded to facilitate its sliding about the walls of the aperture 19 as the element 18 is rotated. As shown in Fig. 5, the length of the rectangular projection 23 extends perpendicularly to line 40 radial to the axis 24 of rotation of the clamp element 18.

In the position shown in Figs. 4 and 5, the inner side surface 31 of the projection engages the end wall 19a of the aperture 19. Upon angular rotation of the clamping element 18 in a clockwise direction as viewed in Fig. 5, the upper end 32 of the projection 23 will engage and slide along the upper right-hand rounded corner 1% of the clamp aperture 19. The opposite or loose lower end 33 of the projection 23 moves generally armately away from the wall 19a.

At an intermediate position corresponding to a rotation of the element 18 from the position shown in Fig. 5, the projection 23 extends transversely across and near the top of the aperture 19. Thereafter, the end 32 slides downwardly along the end surface 19:: of the aperture 19, and the other end 33 passes about the rounded upper left-hand corner 19c and then about the upper right-hand rounded corner 19b of the aperture 19.

Finally, the projection 23 arrives at a position opposite that shown in Fig. 5, and corresponding to Figs. 2 and 3. In this position the outer side surface 34 of the projection engages the end 19a of the aperture 19. I

In the clamping position shown in Figs. 2 and 3, the band 16 has passed slightly beyond a condition of maximum stress only slightly exceeding the stress in the band 16 when the parts are in the clamping position shown. Maximum stress in the band 16 occurs when the clockwisemost end 32 of the projection 23 is inwardmost along the length of the outer support 20 immediately before arrival of the parts to clamping position. Stability is thus achieved by virtue of the resistance of the tubular member 15 to increased compression and the resistance of the band 16 to increased strain.

The clampelements 18 can be operated between clamping and unclamping position by movement. The aperture 19 is of such size and so located as to permit movement only about one 180 path, such as in a clockwise direction as viewed in Fig. 5. For this purpose, the aperture 19 is so located that it extends further above the line 24 than below it; and the aperture is long enough to permit rotation of clamp projection 23 in a clockwise direction through 180. The length of the aperture 19 below the line 24 precludes full 180 arcuate movement of the projection 23 thereabout in a counterclockwise direction as viewed in Fig. 5. By virtue of this asymmetry, the support 21 has a cross sectional area in a plane passing through the aperture 19 for sustaining the stress in the parts. Low unit stress is thus achieved without increasing the width or thickness of the support 21.

The gripping member 15 is constricted by the metal band 16 so that its inner periphery is tightly held against the periphery of casing 10. A circumferential tensile stress is efiective on the band 16 to maintain the constricted gripping member 15 securely in place upon the casing 10. The band 16 being made from a continuous strip of sheet metal, serves to distribute the constricting force over the area of the member 15 which is in contact with casing 10.

When the parts are in clamping relationship as shown in Figs. 2 and 3, the end 32 of the projection 23 is opposed to the lower side surface 19d of the aperture 19. This surface 19d forms a relatively sharp corner with the operative surface 19a. Interaction of the end 32 with this side surface 19d at the corner resists further movement in a clockwise direction of the clamp element 18. This resistance apprises the operator that a stable clamping position has been reached. Furthermore, should the op erator desire to loosen the collar about thev casing 10, this resistance apprises him that rotation of the element 18 is.in the wrong direction. Accordingly unclamping movement of the element 18 is properly accomplished by counterclockwise rotation of the element 18, as viewed in Figs. 2 and 3.

To ensure against uncoupling movement of the clamping element 18 from aperture 19 when in clamping position, a guiding plate 35 is provided. This guiding plate 35 is secured between the inner support 21 and the end 16b of the band 16. The plate 35 has a free end spaced outwardly of the support 21 in an amount suflicient to accommodate the terminal portion 200 of the outer support 20; When the clamping element 18 is moved to operative position, the terminal portion 20a of the outer support 20 enters into the space defined by the plate 35 and the inner support 21.

The plate 35 clears the terminal portion 20:: of the outer support 20 when the parts are in the unclamping position shown in Fig. 4, to permit desired coupling of the supports 20 and 21. Y

The terminal portion 20a of the support 20 has a beveled edge that ensures appropriate entrance of the end of the outer support 20 between the plate 35 and the inner support 21 upon movement of the parts to clamping position.

The free end of the plate 35 has a semi-circular recess 37 (Figs. 2 and 4) conforming to the circular rotatable clamping element 18.

The construction of the clamp element 18facilitating rotative placement upon the support 20 is best shown in Figs. 4 and 6. The clamp element 18' has a generally annular periphery, bounded at one end by a peripheral flange 25. The element 18 is guidingly accommodated in a through annular aperture 26 of the support 20. The flange 25 engages a shoulder 27 formed by an enlarged portion of the recess 26 at the inner side thereof. The interaction of the flange 25 and the shoulder 27limits outward movement of the element 18 from the. position shown in Fig. 4.

In order to limit inward movement of the element 18, a stop washer 28 is provided. This stop washer 28 is accommodated in an annular peripheral recess 29 ofthe element 18 accessible on the outside of the support 2.0. Inward movement of the element 18 is limited by engagement of the stop washer 28 with the edges about. the support aperture 26.

For assembling the parts, the stop washer 28may be made of conical form as shown in Fig. 6, and pressed over the end of the element 18 and into alignment with the groove 29 thereof. The conical stop washer 28 when so in alignment with the groove 29 is flattened by a simple operation. Such flattening is accompanied by aslight radial restriction which appropriately locates theinner portion of the washer inwardly of the groove 29.

A non-circular socket 30, extending axially of the element 18, may accommodate a suitable tool or wrench for appropriate rotation of the clamp element 18.

The collar can be placed upon the casing in a short space of time properly to locate the casing centralizer 12 or any other structure intended to be carried to the well casing 10.

In the form shown in Figs. 7 through 12, a collar 40 is shown that may be. used in a manner similar to the collar 13 shown in the previous forms.

A band 41, made of thin strip material such as steel or the like, is accommodated within a tubular member 42, opposite ends 41a and 41b of the band projecting beyond the ends of the tubular member 42.

The band 41 is held in place about the casing 10 by the aid of interengaging locking elements integrally formed at the ends 41a and 41b of the band 41. These elements of the band 41 may be brought together for engagement only by constricting the band 41 about the casing. When operative, the locking elements hold the band 41 in constricted condition for'firm frictional gagement of the. collar with the casing 10.

The locking, elements for the ends 4112 and 41a are formed by outwardly and inwardly bent ends- 43 and 45 respectively.

The bent ends 43 and 45 extend transversely of the band 41 respectively outwardly and inwardly of the casing' 10. Inner operative surfaces 44 and. 46 of the ends 43 and 45 interengage each other to prevent relative separation between theends 41a and 41!). A tongue 47, formed centrally at the terminal portion of the bent end 43 of the band end 41b, enters an aperture 48 provided near the base of the bent end 45 of the other band end 41a. Interengagement of the tongue 47 and the aperture 48 prevents relative sidewise movement between the band ends 41a and 41b when in. interlocked relationship.

The locking elements 43 and 45 are brought into operative relationship by first moving the inwardly extends ing bent end 45 over the outwardly extending bent end .43 of the respective bent ends 4101 and 41b, and then moving the bent ends 43 and 45 toward each other. Such relative movement of the ends 41a and 41b is accomplished by atool 49 shown in Figs. 9, 10 and 11.

The tool 49 comprises a lever arm 50, the end of 'which is adapted to engage the band end 41b. A link arm 51, pivotally mounted on the lever arm 50, is adapted to engage the other band end 41a.

The end of the arm 50 hasa recess or slot 52 in which may be 'seated' the edge at the end of an elongate aperture 53 formed in the band end 41b. The end of the link arm 51 has a hook end '57 in whichv may be seated the edge at the end of an aperture 54 formed in the other band end 41a. The seatsformed in the lever arm 58 and the link arm 51 oppose each other.v

A pin '55,, carried by the link arm 51,v passesthrough a slot 56 formed in the lever arm50' and serves as'a pivot for the arm 51.

In Fig. 9, the band 41 has been placed about the. casing 10, the locking elements43 and 45' being spaced from each other since the band is unstressed. The tool 49 is placed in operative position by causing the hook 57 of the link arm 51 to engage in the slot 54 and the notch or slot 52 of the lever arm 50 to engage in the recess 53.

Whenthe tool 49 is initially placedin cooperative relationship with the band ends 4111 and 41b,- the lever arm 50 cooperating with the band end 41b is inclined substantially to a line 58 extending radially of the casing 10 and passing through the seat-forming notch 52.

Upon angular movement of the lever 50 in a direction corresponding to the arrow 60, the pin 55 is movable in an arcuate path 59 centered about the seat 52.

The path of movement of the pin'55 is suchas to move the link arm 51 slightly outwardly of the casing as it is pulled to the right by the levera'rm 50. The link arm 51, acting through its hook end 57, correspondingly moves the band end 41a.

In the position of the parts shown in Fig. 10, the lever 50 has been moved angularly in an amount suflicient to cause the locking element 45 to overlie the locking element 43. The slot 56 mounting the pin 55 is so located on the lever 50 that it extends in a direction normal to a 'line joining the pin 55 and the seat formed by the hook end 57 when the parts arrive at the position shown in Fig. 10. Accordingly, upon a slight further movement of the arm 50, the force produced by the stress in the band 41 acting through the link arm on the pin 55 causes the pin 55 to slide to the opposite end of the slot 56, thereby moving the link 51 and the end 41a inwardly of thec-asing 10.

In the position shown in Fig. 11, the pin 55 slides to the opposite end of the slot 56, and causes corresponding movement of the link 51 so that the locking elements 43 and 45 relatively move into engagement. The locking elements 43 and 45 supplant the tool 49 in providing forces for maintaining the band 41 in constricted condition, and the tool 49 can be removed from the band simply by reverse angular movement of the lever 50.

In the assembled position of the band 41 shown in Fig. 11, the band end 411), on which is formed the outwardly extending locking element 43, rests against the wall of the casing 10. To permit access of the lower end of the lever 50 beneath the band end 41b and to permit removal thereof after the band is in assembled relationship, the band end 41b is bowed slightly outwardly. A space 61 is thereby provided in which the lever arm end may be freely accommodated.

As shown in Fig. 12, the operative end of the link arm 51 is offset so that the reactions at the respective seats formed by the tool 49 are aligned, avoiding an undesired turning couple on the tool.

In the form shown in Figs. l4, l and 16, a band 62 is shown that is structurally similar to the band 41 shown in the previous form. In this instance, however, the band 62 forms an integral part of a scraper structure intended to be positioned on the casing 10. A series of scraper elements 63 is secured in place upon the band 62. Each scraper element 63 is generally of wire or rod-like con figuration, projecting radially outwardly through a transverse aperture 64 in the band 62 (Fig. 16). An integrally formed head 65 on each scraper element 63 abuts the edges about the band aperture 64 on the inner side of the band properly to orient the scraper element 63.

A resilient member 66, generally similar to the member 15, is provided for ensuring proper frictional engagement of the scraper with the casing 10. Opposite lateral edges of the band 62 are accommodated in recesses 67 located on the inner sides of outwardly extending flanges 68 of the resilient member 66. The outer surface of the hand 62 is thus exposed.

In Fig. 15, the band 62 is placed in operative position by the .tool 49. The tool 49 operates in the same manner as in the previous form. The band 62 has locking elements 69 and 70, as in the previous form. Recesses 71 and 72 near the ends of the band 62 cooperate with the tool 49 for constricting the band 62 about the casing 10.

In the form shown in Figs. 17 and 18, theends 80a and 80b of a metal band 80 are held together in a slightly different manner. The band ends 80a and 80b have integrally formed rounded ends 82 and 83 forming eyes capable of being aligned to receive a cotter pin 81. The eyes 82 and 83 are brought into alignment by the tool 49, as shown in Fig. 18.

By virtue of the structures being capable of attachment to the casing without a Welding operation, the desirable metallurgical properties of the casing 10 are retained.

The inventor claims:

1. In a stop collar adapted to be mounted on a well casing: a split band adapted to be disposed about the exterior of the well casing; a pliant elastic gripping memher extending at least within the band and adapted to be compressed in gripping engagement with the casing upon constriction of the hand; the end portions of the band on opposite sides of its split providing projections extending in opposite lateral directions and adapted to be placed in overlapping engagement with each other to prevent circumferential separation between the band ends and to maintain the gripping member in gripping engagement with the casing; said band having apertures in its end portions adapted to receive a means for shifting said end portions toward each other to grip the gripping member with the casing and to place said projections in overlapping engagement with each other.

2. In a stop collar adapted to be mounted on a well casing: a split hand adapted to be disposed about the exterior of the well casing; 21 pliant elastic gripping member extending at least within the band and adapted to be compressed in gripping engagement with the casing upon constriction of the band; the end portions of the band on opposite sides of its split providing projections extending in opposite lateral directions and adapted to be placed in overlapping engagement with each other to prevent circumferential separation between the band ends and to maintain the gripping member in gripping engagement with the casing; said band having apertures in its end portions adapted to receive a means for shifting said end portions toward each other to grip the gripping member with the casing and to place said projections in overlapping engagement with each other; one of said end portions having a terminal opening adjacent its projection; and a tongue on the terminal portion of the projection of the other end portion disposed in said opening to prevent relative axial movement between said end portions. l

References Cited in the file of this patent UNITED STATES PATENTS 29,824 Roe Aug. 28, 1860 1,030,073 Gibbs June 18, 1912 1,431,423 Reinboth Oct. 10, 1922 1,965,207 Walker July 3, 1934 1,994,819 Hartson Mar. 19, 1935 2,247,398 Owens July 1, 1941 2,251,428 Smith Aug. 5, 1941 2,374,541 Hartman Apr. 24, 1945 2,417,245 Eggert Mar. 11, 1947 2,432,492 Tinnerman Dec. 9, 1947 2,466,912 Rice Apr. 12, 1949 2,628,134 Williams et al Feb. 10, 1953 2,636,564 Kluck Apr. 28, 1953 2,636,787 Medearis Apr. 28, 1953 2,657,101 Williams et al Oct. 27, 1953 2,674,317 Kipper Apr. 6, 1954 2,683,491 Gassaway July 13, 1954 2,717,650 Hall Sept. 13, 1955 2,721,050

Sams Oct. 18, 1955

Images