US2553838A

US2553838A - Means for suspending and sealing casings

Info

Publication number: US2553838A
Application number: US63497A
Authority: US
Inventors: Allen Herbert; Madden T Works
Original assignee: Cameron Iron Works Inc
Current assignee: Cooper Industries LLC
Priority date: 1948-12-04
Filing date: 1948-12-04
Publication date: 1951-05-22
Anticipated expiration: 1968-05-22

Description

y 1951, H. ALLEN El AL 2,553,838.

means FOR susrsunmg AND smmp CASINGS F11! Doc. 4, 1948 Fig Herbert Allen Madden 7. War/rs //VVENTOR erg; 7% I ATTORNEYS Patented May 22, 1 951 MEANS FOR SUSPENDING AND SEALING CASINGS Herbert Allen and Madden T. Works, Houston, Tex., assignors to Cameron Iron Works, Inc., Houston, Tex., a corporation of'Texas Application December 4, 1948, Serial No. 63,497

Claims.

' This invention relates to improved means for suspending and sealing a casing or other pipe in a casing head.

One object of this invention is to provide a novel structure for hanging a string of casing at any point in its length within a casing head and sealing the casing to the casing head.

Another object of this invention is to provide a slip bowl having downwardly tapered outer and inner faces for respectively engaging the tapered bowl portion of a casing head and supporting a series of wedge shaped slip segments by which the casing or other pipe is engaged. a

- A further object of this invention is to provide a slip bowl which in addition to supporting theslip segments forms a part of the means'for seal ing the casing within the casing head.

. A further object of this invention is to provide slip suspending means for casing or other pipe wherein a divided ring of slip segments are preliminarily attached to a slip bowl by threaded members and maintained in widely spaced raised positions so as to facilitate assembly of the means upon the pipe.

A further object of the invention is to provide a casing suspension and seal apparatus for a cas- .initial closure to permit removal of the control equipment, after which a second seal may be established.

Other objects and advantages will be apparent from the following description taken in connection with the accompanying drawing illustrating a presently preferred embodiment of this invention.

In the drawings:

The single figure is a vertical sectional view showing a string of pipe suspended in its supporting structure with suitable seals in place thereabout.

Referring now to the drawing, the numeral l0 designates a casing head, supported conventionally upon the surface casing (not shown) or other pipe, and provided centrally with an inclined bowl portion H below a cylindrical bore portion 2 of relatively large diameter. The upper end of the casing head H) is formed with a lateral flange l3 provided with a plurality of openings through which it may be bolted to the flange l4 of an upper well equipment member, such as an-' other casing head, blowout preventer valve, or the like. The facing sides of flanges l3 and I4 have registering grooves to receive the metal seal ring l5 which forms a fluid tight seal between them.

A string of well casing or other pipe is suspended from casing head In by the downwardly tapering wedge shaped slip segments whose inner faces are toothedto engage and support the casing l6 and whose outer tapering faces engage the downwardly tapering inner periphery of the slip bowl I8. The lower portion of the outer periphery of the slip bowl I8 is downwardly tap ered to fit the tapered bowl portion I of the casing head while the upper portion of its outer periphery is shaped as a cylinder and of a diameter to fit within the cylindrical portion |2 of the casing head. The upper portion |8a of the slip bowl is also crowned on its upper face to aid in the compression of the resilient packing ring I!) superposed thereon, serving as the lower gland ring in the main sealing or pack-off assembly in conjunction with packing ring I9 and the upper gland ring 20, which has a depending oppositely crowned lower surface for aid in properly compressing and expanding the resilient packing ring l9.

The means for manually compressing and expanding packing ring I9 is herein shown as comprising a series of headed screws 2| having their heads countersunk into openings in upper gland ring 2|] and provided with non-circular sockets for the reception of a suitable wrench. The shanks of screws 2| extend through aligned openings in the upper gland ring 20 and packing ring [9 into threaded apertures in the lower gland ring, herein shown as the upper portion I811 of the slip bowl l8. Screws 2| are tightened down progressively to compress the resilient packing ring l9 and expand it transversely of the axis of the casing to form seals between the casing l6 and the cylindrical portion l2 of the casing head.

Additional seals may also be provided between the slip bowl l8 and both the casing l6 and the casing head, or either of them, in order to form an initial seal between the casing head and casing before the screws 2| are tightened. In the illustrated embodiment, a seal is provided between the tapered outer periphery of the slip bowl l8 and the bowl portion ll of the casing head by providing an annular recess |8b in the slip bowl for the reception of suitable resilient packing ring 22, as, for example, a conventional O-ring. As the slip bowl I8 is lowered into engagement with the bowl portion ll of the casing head, packing ring 22 will be compressed to form a seal therebetweenv Between the casing is and the upper portion [8a of the slip bowl is arranged a. second seal 23, herein. shown as a lip seal of suitable resilient material fitting within a conformably shaped annular recess I80 in the lower corner of the inner peripheral wall of the upper portion I811 of the slip bowl. The lip ring 23 is preferably formed with a divided skirt' portion arranged to be spread by fluid under pressure from the well into sealing, engagement with the casing l6.

Preparatory to mounting the slip bowl and slip segments as an assembly around casing 15, each slip segment H is secured to the lower tapered portion of slip bowl is in raised and retracted position by a suitable screw (not shown) extending through. a suitable aperture ltd. in the slipbowl. andv threaded into a then aligned. threaded. aperture Ila in. the slip segment. The several slip. segments ll may also be maintained all on. the. same level at all times by an outwardly expanding split resilient snap ring 25 arranged in recesses. llb formed in the toothed inner faces. of the slip segments. With the. slip segments held retracted by the bolts as described, the casingv may bereadily manipulated to the point where it is to be hung. Then said bolts are removed, permittingthe slip segments. to. advance with the. slip bowl it into contact with the casing and the. entire: assembly is lowered into the casing head it untilv the. slip bowl i8 seats. in the tapered bowl l! of. the; casing head. Thereupon casing 56- is properly secured in. suspended relation from the casing, head. ring 25 is sufficient. to permit movements of the several slip-segments i'i relatively toeach other out of their. original aligned positions while serving to aid in keeping: them on a. level with each other. At this point it will be noted that an initial seal will have been formed between. the casing and easing head by means of

rings

22 and 23 to prevent blowout of pressure within the annulus about the casing.

The suspension a-nd seal assembly are of such outside diameter as will pass downwardly through the bore of conventional blowout preventer and control equipment which is usually used during the drilling and casing setting operations.

After the casing is set and the seals are installed andtested, if desired, the control equipment may be replaced with other equipment, such as a tubing head, having a reduced bore as illus'- tratedin the drawing.

l After the slip segments ii and slip bowl. l3 have reached their positions with the casing 55: suspended therein, packing ring I9 is advanced over the upper end of the casing to rest on the crowned upper face of slip bowl portion l-Ba and the upper gland ring 20 similarly advanced to" rest on packing ring I8 Headed screws 2i are then threaded into position and progressively tightened down to expand packing ring I9 into sealing engagement with both the casing H and. the cylindrical bore portion 12 of the casing head. The seals may be tested, if desired, by'appmpri'atc testing apparatus before the well is completed,

While the illustrated embodiment is believed. to adequately fulfill the object and advantages herein stated, it is to be understood that this invention is susceptible to modification and variation within the scope of the subjoined claims.

Having described our invention, we claim: 1. In. combination with a casing head having The flexibility of the resilient snap:

4 a tapered bowl portion and a cylindrical bore portion thereabove, means for suspending and sealing a string of casing therein comprising a slip bowl having inner and outer tapered walls and adapted; to fit with-inthe bowl portion of the casing head, a seriesv of slipv segments arranged to cooperate with the inner tapered wall of said slip bowl in suspending the casing, removable means for preliminarily supporting said slip segments in raised positions within said slip bowl, .and means for sealing between the casing and casing head above said slip ring comprising a lowerg-land ring. carried by said slip bowl, a resilient packin ring, and an upper gland ring, headed screws threaded into one of said gland rings being arranged to compress said packing ring and expand it into sealing engagement with both the casing and easing head. f

i 2. In combination: with aca-sing head; having a tapered bowl portion and a cylindrical bore. portion thereabove, means for suspending and sealing a string of casing therein comprisin a slip bowlhaving inner. and outer tapered walls and adapted to fit within the bowl portion of the casing head, a series of slip: segments ar.--- ranged to cooperate with the inner tapered wall of said slip bowl in suspending the casing, means for preliminarily supporting said slip segments in.

raised positions within said slip bowl, packing" means carried by the. slip bowl for sealing itsouter taperedwal-l against the bowl portion, and packing means carried by the slip bowl for sealing its inner wall against thecasing', and means for sealing between the casing and casing head above saidslip segmentsccmprising' a lower gland ring carried by said slipbowl, a resilient; packing ring, and an upper gland ring, headed screwsthreaded into one of said land rings being arranged to compress said packing rin and expand it into sealing engagement. with both the casing and easing head.

3. A well casing support and packofi assembly comprising a slip bowl adapted to: be received by a casing head having a tapered seat with a cylindrical portion thereabove', the upper'portion of the slip bowl being annular and of a dimension to substantially fill the space between a well casing and a casing head, the upper annular sur face of the slip bowl providing a. seat, a packing ringon said seat, a packin gland on said ring, and connection means between said gland and slip bowl which may be tightened to advance the gland toward the slip bowl to expand the packsure diil'erential to be sealed against.

HERBERT ALLEN. MADDEN T. WORKS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS