US2754134A - Oil well hanger assembly - Google Patents

Description

July 10, 1956 J. D. WATTS ErAL 2,754,134

OIL WELL HANGER ASSEMBLY Filed Oct. 8, 1952 5 Sheets-Sheet l I 14' j g I i 26 J2 3 L 2a 32 z 42 4-? J 6 l I 464% 6 4 4 I 5 I. I '1' I l E I 6.2

L QI CU c1 INVENTOR JOHN D. WATTS 8 E'LWOOD K. PIERCE, JR.

ATTOR NEYS July 10, 1956 D. WATTS ET AL 2,754,134

OIL WELL HANGER ASSEMBLY Filed Oct. 8, 1952 3 Sheets-Sheet 2 IIIII/l/ JOHN D. WATTS 8 E'LWOOD K. PIE/POE, JR.

ATTORNEYS July 10, 1956 D, WATTS ET AL 2,754,134

OIL WELL HANGER ASSEMBLY Filed Oct. 8, 1952 3 Sheets-Sheet 3 INVENTOR OHN D. WATTS 8 EL 00 K. PIERCE, JR.

ZMm/w F W ATTOR NE YS United States Patent assignors to Gray Tool Company, Houston, Tex., a cor pbrhtion'of Texas Application October 8, 1952, Serial No. 313,706 3 Claims. of; 285-3 The present inventioir relates to" a hanger, and in particnlara casing hanger, and associated-equipment for use in suspending and" sealing a casing or other oil'well pipe at the casing" head, while providingfor eo'mple'temechani'cal control of the well;- at all stages of the'ope'rations' which are involved.

A principal object of the invention is to 'pr'ovide'such' a hanger, with a slip assembly for supporting thecas'ing or other pipe therein,-the construction being such'that the slip assembly may be conveniently insertedinto, or removed from the hanger body, when desired. This-capability is useful, not only in initially assembling the hanger with its slip assembly, and applying same to thecas'ing or oil well pipe, but also to provide for quick removal'of the slip' assembly from the hanger, after thehanger ha'sbeen initially applied to' the pipe, for'putpo's'es ofadjustingthe position of the hanger on the pipe. That is, the construction is such that the hanger may be reset, with facility, in the event that the initial setting of the hanger on the pipe, is'nOt satisfactory, in view of the conditions whichexist at aparticular well.

The hanger of this invention has the usualbore to slide over and seal with a casing or other oil well pipe; and inaddition, it has an enlarged counterbore which extends to and is open at the lower end of the'hang'er, and theinner wall of this counterbore and the" outer wall of the slip assembly are so constructed that' the slip assembly may be threaded upwardly into the counterbor'e'; ana adjusted therein, for proper gripping of the casing of other pipe, when same is suspended. Furthermore, the construction referred to is such that the hanger may be rapidly unth'rea'ded from the slip assembly, after'an'iiiiti'a'l-setting is made,- whereby the slip assembly may be adjusted with respect to the pipe, after which the hanger may be again threaded over the slip assembly and the parts properly adjusted, in order to reset the hanger, and restspend the casing of other pipe in the well head;

The invention may be employed, for example, with a hanger for use in building safe oil wells by thernethods described in United States Patents Nos; 2,112,444; May 1 7, 1938, and 2,082,413, June 1, 1937, to Mueller and Yancey. The description of applicable structure and steps in operation which appear in these patents" is not repeated detail herein, it being iinders'teo'd that they are referred to as shot ving equipment-arid methodswhfihf would be used with thepresent inventieh and to that eiiten't they form part of the present disclosure;

Further, United States Patent 2,207,469, t'oRoye, my 9, 1940, discloses a practice analogous to the said Mueller et 511. patents but wherein provision is made forptillin'g the casing upwardly after the hanger is landed to remove the slack and put a strain on the casing; slip means being provided in the hanger to support thepipe after the-strain has been taken. The present invention contemplatesuse ofa' hanger with the method of landing a' casing'as disclosed in the above mentioned Roye patent buthavi'n further refinements of the practices disclosed therein; Therefore, the Roye patent is mentioned to-disclose the details and description ofan applicable structure i'r'f'the operation of landing a casing in a casing head and su'c'hf steps are notrepeatedherein in detail; it bei'n'g. understood that they are referred toasdisclosing well-known equip: ment and methods which would be'used with th'e resent invention, and to that extent they forin' part of the pres: ent disclosure. 7

Another object of the inve'ntionfi'sto"provide' stranger capable of suspending extremely long c'a'singstring'sin a casing head while providing complete meelianical control of the Well at all times. In modern day practices, it is necessary to drill wells of extreme depths to penetrate new producing sands. In some instanee's, it'is" necessary to drill asdeep as twenty thou'sand fe'et or more, and we have developed a hanger for supporting gieater lengths of-casing-th'a'n was required iri thepastl We disclose herein a hanger of tli'e general typedisclesed in a' co pending" Mueller et' ali application; Serial No. 680,334, filed June'28 1 946, now'pate nt 2,62434'1'3, January 6; 1953, but wherein the hanger body isfa'bricated as a unit and having means for inserting the slips after'tlie hanger body'has'heen fabricated. The provision of a* hanger body wherein the'slip's are inserted after the hanger body has beencompletely fabricated as a unit iricreases the strength andutility of the'hanger and decreases nianufactnring' was We disclose herein a form ofslip suspension of the pipe" within the hanger whereby the metal of the hat-l ger body ma he maintained at maximum strength and thickness at the point of suspension of the hanger in theca's'i'n'g head;

The hanger disclosed herein is provided" with relatively long s'lip'segm'ents for grippingand supporting thefc'a'sing. or other pipe, said slip' segmehtshaving uniform Contact with" the casing, thus" distiihutihg the load uniformly to the hanger body andcasihg head The slip'seg'ments'a're of minimum thitil zi'ies's so as to'- bend and re-distrihut'e' the load more" evenly alongthe entire lengths of the se ments; Such" a constructieh provides for maximum thicllne'ss of The present inventioa provides a hanger With slips of the general type diselbsed in Mueller et 211;, 2,624,413, which are threaded into position in the hanger Badge-nu 9 are s6 for-med, that means extending through the'wall of the hanger prevent the slips from unthreading; yet allowing the limited vertical movernent of the slips in the hanger, as isn'e'cessary to' suspend the casing; As referred to above, the construction provides for resetting-the hange'n if necessary, by lifting the cas in'g: out of the casing head andunth'readin'g the hanger from the slip assembly; whereby the slip assembly may be; adjusted on the casing and threadedback into the hanger, the hangerther'eb'y' being capable often-1g reset on the casing. The cens'truot ion disclosed herein pro: vides means fofci'rcunifer'entially spacing the slip segments or elements from one another, and to hold them in retracted position whet ate hanger" is being lowered over a casing.

Other objeets and advantages of the present raven-'- tio'fi, including simplieity aria cheapne's's 'of manufacture, ans c'o'nveh'iefic'e' in use, will be apparent as the descrip tiort herein progresses;

In the drawings',-which illustrate a preferred embodi= merit of the invention',-- and aren'ot intended tdrestr'ict the invention to any precise form:

Figure I- is a partial verti'eai sectional view through the casing head Of a well, Showing" a hanger'lan'd'ed there' in, with slip" stis 'en'sien means in the hanger, the situa ticsii portra ed bein that-whieh would exist just rior to the downward mcveeieritef the slips" into their pjipe gripping position;

Figure 2 is a vertical sectional view similar to Figure 1, but showing the condition of the equipment after the slips have been moved downwardly into pipe gripping position. As in the case of Figure l, the control equipment has been omitted, but it will be understood that the casing and hanger have been lowered through such control equipment as disclosed in the prior patents and application referred to above. For instance, the casing and hanger would be landed through control equipment as shown in Figure 6 of the Roye Patent No. 2,207,469, as disclosed therein.

Figure 3 is an enlarged top plan view of the four slip segments or elements, which comprise the slip assembly .of the hanger.

Figure 4 is a fragmentary vertical sectional view taken along the line 44 of Figure 3.

Figure 5 is a fragmentary side elevational view of the slip assembly.

Figure 6 is a horizontal sectional view taken along the line 6-6 of Figure 2.

Figure 7 is a similar horizontal sectional view taken along the line 77 of Figure 2.

Figure 8 is a partial vertical sectional view taken through the pipe being suspended, and the body of the hanger at the lower end thereof, showing the means for guiding the slip elements in their relative vertical movement, while preventing unthreading movements thereof.

Figure 9 is a vertical sectional view, illustrating a well head assembly, for three strings of pipe, showing a part of the well head installation which results from the building of a well, employing the equipment of the present invention.

Referring to Figures 1 and 2, the invention is shown in use, in landing an inner casing or other oil well pipe C within the outer casing C which has been previously landed. Attached to the upper end of the outer casing, there is a now conventional casing head E, in which is landed a hanger which is generally designated H.

The casing head E is of the full opening type, with respect to the casing C on which it is mounted, and the control equipment which is employed, and which is mounted on and above the casing head E, is of the now standardized rated size, in relation to the casing C on which it is mounted. The casing head E has an outwardly flaring seat 10, and the control equipment as ferrcd to, has a full bore, substantially equal to the maximum diameter of the seat 10. The control equipment may be attached to the casing head by the usual flange connection, or by any other suitable connection.

The hanger H comprises a body having a bore 12 extending therethrough, said bore being slightly larger than the outside diameter of the casing C whereby the hanger may slide over this casing. The hanger body has an upper tapered sealing surface 14, to seal with an upper casing or tubing now well known in the art, and a lower tapered sealing surface 16 which seats and seals in the seat of the casing head, the hanger having suitable circular packing rings 18 therein, to make this seal more effective, as is known in the art.

Within the bore of the hanger, there is an enlarged recess 20 of the shape shown in Figures 1 and 2, and a sealing element of rubber or rubber composition, such as neoprene, is carried in this recess. The sealing element snugly fits the recess 20 and protrudes slightly therefrom, to engage and seal against the outer wall of the pipe being suspended. The sealing element is hollow, providing an interior pressure chamber defined in part by an inner sealing wall 22 which engages the pipe being suspended. The wall 22 has a series of openings 24 therein, whereby when the hanger is landed, and pressure is exerted upwardly on the sealing element, the lower part of the wall 22 is forced inwardly, to expose the openings 24 and admit pressure to the interior of the sealing element, which pressure exerts itself upon the uphead, as illustrated in Figure 9, and

per portion of the wall 22, expanding same into intense sealing engagement with the outer wall of the pipe being landed. The construction of this sealing element, and its manner of operation, as briefly referred to above, is described in detail and claimed in an application of John D. Watts and Elwood K. Pierce, ]r., entitled Well Head Pipe Suspension, Serial No. 315,002, filed October 16, 1952.

It will be understood that when the inner casing C has been lowered into the well to approximately the roper point of suspension, through the control equipment, the hanger H is slidably positioned over the last joint of casing, and is lowered through the control equipment to its seat. The general manner of lowering the casing and hanger, is described in the aforementioned Roye patent, and referred to in Mueller et al., 2,624,413. When the hanger reaches its seat in the casing head, and the weight of the casing is taken on the slips in the hanger, there is a seal formed between the lower tapered surface of the hanger, and the seat in the casing head, and simultaneously, an effective seal is formed between the bore of the hanger and the outer wall of hte casing, by action of the sealing element, previously referred to, which seal is made more intense by the upward action of any pressure which may exist in the well.

The lower end of the bore 12 through the hanger, is enlarged .to form a substantially cylindrical counterbore 26, which is closed at its upper end, but which extends downwardly to and is open at the lower end of the hanger. The counterbore 26 is positioned below the lower end of the outside tapered surface 16 of the hanger, so that the hanger body has maximum wall thickness at the point where it engages and seats, in the seat of the casing head. As will be hereinafter described, the casing C is supported by a slip assembly in the counterbore 26, and the resulting vertical separation of the suspension point of the hanger in the casing head, from that of the pipe in the hanger, makes these suspension points independent of one another, preventing any distortion of the metal parts at one suspension area from accelerating any distortion at the other suspension area.

This hanger, formed as described, is structurally stronger than hangers of the prior art, at the point where compression forces on the hanger are at a maximum. This is of some importance in modern oil well operations, because hangers are now required to support casing strings of extreme length.

The interior wall of the counterbore 26 is formed with a continuous spiral surface, having downwardly and inwardly inclined slip guiding areas 28 positioned one above another in vertical alignment. Similarly and exactly cut inclined exterior areas 30 are provided on the outer walls of the slip elements. The areas 28 on the wall of the counterbore are separated by continuous downwardly presented horizontal spiral cut ledges 32, and the guiding areas 30 on the slips are separated by similarly formed ledges 34. The surfaces 28 and 30 are formed by spiral surfaces of fixed lead, the surfaces 28 extending from the upper end of the counterbore to the lower open end thereof, so that the slip assembly can be threaded upwardly into the counterbore, through the lower end thereof, and the hanger can be unthreaded from the slip assembly, as previously referred to. The surfaces 28 and 30, and the ledges 32 and 34, are cut or formed as described in Mueller et al., 2,624.413.

As shown in Figures 3 through 5 and as shown installed in Figures 6 and 7, there are four arcuate slip segments L'separated from one another by slots 36. In cutting'the slots 36, sufficient of the metal may be removed so that the slip segments may move toward one another as they grip the pipe, during their movement from the position of Figure l, to that of Figure 2. The movement of the slips, between retracted and operative positions, is a limited vertical and inward movement of the slip segments, which is permitted by the formation of the inner wall of the counterbore and the formation of the outer wall of the slip segment, as previouslydescribed. As best shown in Figure 4, the inner facesof the slip segments are formed with the upwardly presented gripping teeth 38, which grip and suspend the pipe in the usual manner, as is well known in the" art.

In Figure 1, the slip'segments' are shown in their'upper orretract'ed' positions, which they assume when the hanger body is slidably moved downwardly over the upper end of the casing C the friction tending to move the slip segments'upwardly and away from the casing C When the hanger is landed in the casing head, and when the usual upward support fromthe derrick on thecasing- C is released, the clip segments are caused by the casing to slide downwardly, controlled by the engagement of the surfaces 28 and 30',- and' as the segments move downwa'rdly, they move inwardly, whereby their teeth engage the casing to support and suspend same.

Stated otherwise, when the slip segments move to grip the inner casing, the ledges 34 move downwardly from the ledges 32, because of the limited vertical movement of the slip segments, and because of the engagement of the inclined surfaces 28 and 30. This downward movement is accompanied by an inward ipe gripping movement. The spiral surfaces and ledges referred to, are cut by an appropriate machine tool, as in the case of cutti'ngfa thread witha fixed lead.

Again referring to Figure 4, the inner faees of the slip segments are also formed with a groove 40, which is continuous from' one segment to another when same are in proper alignment, this groove being out of phase with the outside spiral surface 30 of the slip segments. This groove 40 may' extend for approximately two complete' turns around the interior wall of the slip assembly. A spring wire 42, as shown in Figure 2, formed to the same shape" as thespiral of groove 40, is inserted into this groove preliminary to inserting" the slip assembly into the counter-bore of thehanger, this'spring wire serving to properly align the slip segments with respect to one another, in order to align their companion spiral surfaces 30,- and to facilitate the assembly of the slip segments into a unitary slip assembly. Thereafter, the assembly thus mounted onthe' spring wire 42, may be threaded upwardly into the counterbore of the hanger, to its proper position. At this time, a locking screw may be threadedthrough the openings 44 extending through the body of the hanger,- as shown in Figure 6 and into the threaded openings 46 in the body of the slip segmerits,- in order to lock the slipsegments in their retracted position, as shown in Figure 1. It will be understood,- as is known in'fhe' art, and as disclosed in the Roye patent, that when the hanger is initially slidably positioned over'the casing, the set screws referredto are unthreaded and removed from the openings 46 and 44, before sliding the hanger downwardly through the, control equipment, so that the slip segments are released for downward movement, when the hanger reaches the" landingposition, as shown-inFigure' 1;

As best shown in Figures 7 and 8, the hanger body is provided with openings 48 and guide screws 50 are threaded through these openings after the slip assembly is initially installed to proper position within the counterbore of the hanger body. These guide screws pass between the adjacent edges of the slip segments, i. e., into the openings 36 (Figure 3) and when so positioned, they act to restrain the slip segments against any unthreading movement. With this construction, and when the slip segments are so installed, and locked in place, and upon removal of the set screws from the openings 44 in the hanger body, the slip segments are capable of the limited vertical movements previously referred to, and yet are restrained against any substantial rotary movement, whereby they cannot be unthreaded from the counterbore without first removing or retracting the guiding screws 50.

With the construction as described, and as previously referred to; it will be evident that the slip assembly, composed ofits slip segments, may be assembled into aunit on the spring wire 42 and threaded upwardly into the counterbore of the hanger body.- At this time, the guide screws 5 0 and the set screwswhich are threaded into the openings 44 in the hanger body, may be installed, to hold the slips in their proper retracted positions. Upon removal of the set screws from the openings 44, after the hanger is positioned on the casing, the hanger may be passed downwardly through the control equipment to its seat as shown in Figure 1. When the tension of the casing C is released, the slip segments move'downwardly from the position of Figure 1 to the position of Figure 2, to support the casing in the well head, a seal being formed between the hanger and the casing head, and between the bore of the hanger and the outer wall of the casing C as previously described. If it is found that the hanger setting thus effected is not satisfactory, dependingon the conditions existing at the well, the casing maybe moved upwardly until tlie hangeris again above the control equipment, at which time; upon removal or retraction of the guide screws 50, the hanger body may be unthreaded upwardly from the slip assembly, which is still'substan tially retained as a unit, by the spring wire 42. Thereafter, the slip assembly may be adjusted in position on the casing C and the hanger body'rnay then be threaded over the slip assembly, and secured by the guide screws 50', against unthreadingaction, as previously described. Thus; the equipment is constructed for convenient resetting. of the hanger, in casethis is necessary. v

It will be noted that the shank portion S of the hanger bodyis' of relatively great length, so that the slip engaging areas' in thecount erbore, and the slip segments themselves, are ofrelatively great length, as compared with hangers of this type, known in the prior art. With this construction, the load of thecasing will be uniformly distributed throughout the length of the slip segments, to the hanger body, there being a relatively great number of pipe engaging. teeth 38' on the inner faces of the slip segments, to distribute this load. The suspension area, where the slipsengage the pipe, is positioned below the uspension area where the hanger engages the casing head, resulting in an advantage as previously referred to, and the metal thickness of the hanger body is at a maxiwhere it supports the casing in the casing head.

It will be understood that when the casing is landed with this han'ger,- as previously described, the well is under cemplete mechanical control, there being seals formed both betweenthe hanger and the casing head, and between debate of thehanger and the outer wall of the casing. The interior of the casing will be sealed, by the usual means, such as aback pressure valve, employed forhthis" purpose, within the casing. When the casing is landed, the control equipment may be removed, and the next casing head may be mounted, to seal with the upper tapered surface 14 ofthe hanger body, as previously referred to, whereupon the succeeding operations in building'the well, may be practiced, as referred to in the aforementioned Roye patent, and in Mueller et al. 2,624,413, and as referred to in U. S. Patents Nos. 2,117, 444 and 2,082,413, previously mentioned. Of course, if the hanger is used on the final string of casing being landed, a tubing head may be mounted above the hanger, preliminary to the practice of completion operations and using equipment as now well known in the art, for instance, as described in such prior art patents as Yancey, No. 2,241,288, dated May 6, 1941, or Smith et al., No. 2,148,327, dated February 21, 1939.

It will also be understood that upon removal of the control equipment, and prior to mounting the next tubing or casing head, the hanger may be permanently secured to and sealed to the casing, as by welding the same, as indicated at 52 in Figure 2, as described in the aforementioned Roye patent. Such a welding operation is customarily performed after the control equipment is removed and when the casing is supported by the slip segments, the hanger being in turn supported in the bowl of the casing head. Another practice for permanently sealing the hanger to the casing is disclosed in a copending application Serial No. 650,272, Mueller et al., filed February 26, 1946, now Patent 2,620,880, Decemher 9, 1952. In that application, a hanger and associated means are disclosed, providing for the cold rolling of the casing into permanent sealing engagement with the hanger in order to form a permanent union between the casing and the hanger. The details and description of applicants structure and steps in the operation which appear in the above mentioned application are not repeated herein, it being understood that they are referred to as disclosed equipment which could be used with the present invention, and to that extent, they form a part of the present disclosure.

We claim:

1. A hanger to he landed in a casing head comprising a unitary body having a bore to pass over and closely embrace an oil well pipe and having an exterior surface to seat in and form a seal with the casing head, said hanger having an enlarged counterbore which extends to and is open at the lower end of the hanger, the wall of said counterbore being provided with downwardly and inwardly inclined slip engaging surfaces extending to the open end thereof, a plurality of separate removable slip elements of thickness permitting their insertion into and removal from said counterbore through the lower end thereof, said elements having inner faces formed with pipe gripping teeth and outer faces provided with downwardly and inwardly inclined surfaces to engage the said inclined surfaces on the wall of said counterbore, said inclined surfaces on said slip elements and on said wall being formed in a continuous spiral of fixed lead providing for limited vertical movement of said slip elements in said counterbore between pipe gripping and retracted positions and for the threading of said slip elements upwardly into said counterbore and the upward unthreading of the hanger from the slip elements to readjust the setting of the hanger on the pipe, said slip elements being of such width as to leave a slot between one another when they are assembled in said counterbore around an oil well pipe, and means on said hanger entering said slot to prevent unthreading movement of said slips while providing for its limited vertical motion when the hanger is applied to a pipe, said means on said hanger comprising a plurality of adjustable guide screws extending through the hanger body and into the slots between said slip elements whereby the latter may be unthreaded merely by the removal of said screws from said slots.

2. A hanger as defined in claim 1 wherein said counterbore and said slip elements are positioned below said exterior seating surface of said hanger body so that the latter has maximum wall thickness at the level of said exterior seating surface where it is subjected to maximum compressive forces and said slip elements grip and support the inner pipe at a level entirely below that of said exterior seating surface of said hanger body.

3. A hanger for supporting and sealing an inner oil well pipe in the seat of a casing head which is mounted on an outer casing, comprising a metal body, said body having a bore therethrough to closely embrace and slide over the inner pipe and including an upper seating portion and a lower shank portion rigidly joined therewith and extending downwardly therefrom, said seating portion having a downwardly and inwardly inclined external seating surface extending to and terminating at the upper end of said shank portion, constructed and arranged to he landed on and to snugly seat in a complementary former portion of said head, said shank portion having an enlarged counterbore formed therein, downwardly and inwardly inclined surface means in said counterbore disposed entirely below said seating surface, and a slip assembly disposed in said counterbore entirely below said seating surface in engagement with said inclined surface means for gripping and supporting the inner pipe when the hanger is landed in the casing head, the juncture area of said upper seating portion and said lower shank portion forming a neck portion having a larger internal diameter than said seating portion or said shank portion, the external diameter of said neck and shank portions being less than the smallest diameter of the upper seating portion and of said casing head, said neck and shank portions being thereby removed from any load bearing contact with the casing head, said seating surface thereby constituting the sole load bearing area of contact with the casing head so that the compressive forces occasioned by such contact will be concentrated in the hanger body at the level of said seating surface, said counterbore being positioned relative to said seating surface so that said hanger body has maximum wall thickness at said level to resist said concentration of forces, said wall thicknesses being related to the position of the slip assembly so that the latter is substantially unaffected by said concentration of forces and is operable to grip and support the inner pipe with an even pressure throughout the entire area of contact therewith.

References Cited in the file of this patent UNITED STATES PATENTS 2,082,413 Mueller et al. June 1, 1937 2,117,444 Mueller et al. May 17, 1938 2,148,327 Smith et a1 Feb. 21, 1939 2,207,469 Roye July 9, 1940 2,241,288 Yancey May 6, 1941 2,485,497 Lemley Oct. 18, 1949 2,616,752 Osmun Nov. 4, 1952 2,620,880 Mueller et al. Dec. 9, 1952 2,624,413 Mueller et al. Ian. 6, 1953 FOREIGN PATENTS 597,822 France Sept. 11, 1925 338,674 Great Britain Nov. 27, 1930

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