US2400254A - Casing head - Google Patents

Description

May 14, 1946. I 'A. J. PENICK CASING HEAD Filed June 16, 1944 Patented May 14, 1946 UNlTED STATES PATENT OFFICE Application June 1e, 23:. 540,683

40mins.

This invention relates to a casing head and has particular relation to a packing assembly for forming a seal with the casing head and with the inner pipe which extends through the casing head into the well.

A-further object is to provide a sealing assembly of the character described which may be mounted on the inner tubing and lowered into the well through the blowout preventer and secured in the casing head'beiore the blowout preventer is removed.

Therefore, while lowering the tubing the blowout preventer. may be maintained installed and in readiness for use, in case of a threatened blowout, until the inner pipe is securely sealed with the casing head and secured in place.

Another object of the invention is to provide, in a casing head seal, suitable sllpsfor mounting the sealing assembly on the inner pipe or tubing preparatory to lowering the-same, with the tubing through the blowout preventer and into the casing head.

Withthe above and other objects in'view the invention has particular relation to certain novel features of construction, arrangement of parts and use; an example or which is given in this specification and illustrated in the accompanying drawing wherein:

The figure shows a side view of the complete assembly shown partly in section.

Referring more particularly to the drawing the numeral I designates the well casing on which the casing head 2 is mounted.

This casing head has an inside downwardly converging seat 3 and beneath the seat has one or more outflow lines as I.

The upper end of the casing head has an external annular flange I provided with an upwardly facing annular groove 6 to receive the annular seal ring I. r

8 having the external annular flange 9 at its lower end and provided with the annular groove It! to receive the ring 1 to form a fluid tight seal.

The flanges and 9 may be clamped together by suitable clamping bolts ll.

Mounted on the tubing head there is a blowout preventer l2 of anyconventional construction for forming a seal about the inner pipe or tubing l3 as the same is lowered into the well. This blowout preventer is provided to guard against blowouts in case high pressure develops in the well.

It is secured on the tubing head by bolts l4 and sealed therewith by the seal ring I 5 similar to the ring 7. I

For the purpose of forming a fluid tight seal with the casing head and with the tubing l3 a retainer l8 has been provided. This retainer is tapered downwardly externally to conform to the taper of the seat 3 and the retainer l6 has the surrounding packing rings l7 countersunk therein which form a secure seal between the retainer and the seat 3.

,Within said retainer there is sleeve like packing I-l which closely surrounds the inner pipe or tubing I3. The lower end of the retainer has an inside, annular shoulder I9, in which the lower end of the packing I8 is dovetailed. The 'shoulder ll colsely surrounds the inner pipe l3.

Above the retainer l6 there is a slip bowl whose inner side converges downwardly forming a slip seat 2| whereon is mounted a plurality of wedge shaped slips 22, whose inner surfaces are toothed to engage the inner pipe I3.

A ring nut 23 is screwed into the upper end of the slip bowl against the slips to hold them in secure engagement with the inner pipe.

The lower end of the slip bowl is reduced and fitted within the upper end of the packing retainer l6 from a gland 24 whose lower end engases the upper end of the packing sleeve I 8. This gland has external longitudinal keyways as 25 and threaded through the upper end of the retainer ii there are keys 26 whose inner ends pro- 30 ject into said keyways so as to allow vertical movement of the slip bowl relative to the packing retainerbut to prevent their complete separation.

.The upper end'packing retainer IS- has an external downwardlyand outwardly tapering face 2'! and extending radially through the flange 5 the cause 5 to form seals about the bolts 2a. 0n the casing head there is the tubing head These bolts may be screwed inwardly to force the retainer I 6 downwardly so as to apply a compressive force to the seal rings I1 and to thus form a fluid tight joint between the retainer IB and the casing head.

tapering face 3| of the slip bowl. Suitable seals flange -9 around the lock 32 are mounted in the down bolts 30.

The inner tubing I3 i made up and lowered into the well through the blowout preventer and casing head and as a final ste of completing packing l8 therein the installation of the inner tubing the sealing assembly, including the retainer IS with the and the slip bowl and slips, is placed on the tubing above the blowout preventer and is lowered with the tubing through the blowout preventer and lands on the seat 3 of the casing head. The bolts may then be screwed inwardly to force the retainer downwardly to compress the packing rings l1 and form a tight seal with the seat 3. The weight 01 the tubing 7 on the slips and slip bowl will usually be suflicient to compress the packing sleeve l8 so as to form a fluid tight seal around the tubing l3. However, the lower end of the tubing I3 is usually cemented and the heat in the well sometimes causes expansion and upward movement of the tubing 13 so as to relieve the compression on the packing l8 permitting leakage. In such case the bolts 30 may be screwed inwardly against the face 3| which will force the slip bowl 2!! and gland 24 downwardly to apply a compressive force to the packing sleeve l8 thus causing its expansion so that it will maintain a tight seal around thetubing l3.

When the tubing has-been landed in position and the sealing assembly installed the blowout preventer l2 may be removed with safety and the Christmas tree or other flow connections then installed.

What I claim is:

1. In well head construction having an inside seat; a retainer formed externally to fit onto. and form a seal with, said seat and having inwardly projecting keys, an annular seal ring within the retainer to form a seal with an inner pipe through the head, a slip bowl having external vertical keyways to receive the keys and movable against said seal ring and slips in the bowl engageable with said inner pipe.

2. In well head construction having an inside annular seat; a retainer formed externally to fit into, and to form a seal with, said seat and having an inside projection, an annular seal ring formed of resilient material within the retainer to form a seal about an inner pipe through the head, a slip bowl having an external vertical keyway to receive said projection whereby the bowl is loosely connected to the upper end of the retainer but movable against said seal ring to compress the same, slips in the bowl engageable with the inner pipe and a ring nut threaded into the bowl against the upper ends of the slips.

3. In well head construction having an inside downwardly converging annular seat; a retainer formed externally to fit into said seat, an external annular packing ring countersunk into the retainer and forming a seal between the retainer and seat, a sleeve like seal ring within the retainer to form a seal with an inner pipe through the head, a slip bowl whose lower end is fitted into, and has a slip joint connection with, the upper end of the retainer and abuts the upper end 0! said seal ring. said bowl having an inside downwardly converging seat, gripping means in the bowl on said seat engageable with said inside pipe, a ring nut threaded into the bowl and abutting the upper end of the gripping means.

4. In well head construction having an inside downwardly converging annular seat; a retainer formed externally to fit into said seat, an external annular packing ring countersunk into the retainer and forming a seal between the retainer and seat, a sleeve like seal ring within the retainer to form a seal with an inner pipe through the head, a slip bowl whose lower end is telescoped into, and slackly connected with the upper end of the retainer and abutting the upper end of said seal ring, said bowl having an inside downwardly converging seat, gripping means in the bowl on said seat engageabie with said inside pipe whereby the weight of the pipe will be supported, through said bowl, on the seal ring, a ring nut threaded into the bowl and abutting the upper end of the gripping means, and means on the head accessible to an operator and engaging with the retainer and the slip bowl, respectively,

and effective to force the same downwardly to apply a compressive force to said seal rings.

ARTHUR J. PENICK.

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