US1900260A - Multicap casing head - Google Patents

Description

March '7, 1933. w. D. SHAFFER 1,900,260

MULTICAP CASING HEAD Filed June 6, 1930 INVEN TOR,

" ATTORNEY.

' Patented Mar; 7, 1933 WILLIAM D. SHAIFER,

or BREA, CALIFORNIA MULTICAP CASING HEAD Application filed June 6,

This invention relates to what is known as casing heads such as are employed in wel drilling practice and well systems.

In such systems it is frequently the prac- .5 tice to telescope one or more inner casing strings (of pipe).

It is desirable to cap off each casing string in a close-cut relation; to enable the capping without cutting and threading the, casing 10 tops and without application of threaded fittings; to provide a slip-device to grip and suspend each respective casing individually, and to provide means for making a gas seal and which means 15 is adapted to be installed and replaced or reand each cap having an internal, adjustable packing gland device accessible from its top.

The invention consists in certain advancements in thisart as set forth in the ensuing disclosure and having, with the above, additional objects and advantages, and whose construction, combination and details of means, and the manner of operation will be made manifest in the description of the herewith illustrative embodiment; it being understood that modifications, variations and adapta- 35 tions may be resorted to within the scope,

principle and spirit of the invention as it 1s more directly claimed hereinafter.

The drawing is a partial elevation an axial section of assembled casings and the applied head.

The present casing head comprises a sill or base collar 2 fitting the outer casing O and having an internal shoulder 3 bored to about the inner diameter of the casing 0 so that collars of an inner casing I may freely pass up or down. This sill collar 2 is provided with a base flange 4 to rest on a cellar frame or other foundation.

Superimposed on the collar 2 is a cap sec- 50 tion 5 with a bottom ring-bead 6 registering a simple and practicable- 1930. Serial No. 459,436.

with a packing groove 6' in the top face of the collar 2 and compressing a packing 7 therein.

The cap 5 has a base flange 8 and is attached by bolts 9 therethrough to the sill collar 2. and has a top flange 10- for attachment of a similar cap element. The body of the cap '5 has a downwardly convergent bore 5 of such minor diameter as to pass coupling collars on the casing I gripped and suspended by a set of taper slips 12 setting in the cap 5 and whose upper endsare provided with screw holes 13 for pulling tools (not shown). v

A gas outlet connection 14 opens through the cap 5 to the space below it and about the casing P. A feature of this cap is to provide for effective packing against very high gas pressures sometimes encountered in wells. As here shown the cap bore has a cylindrical upper portion threaded to receive a follower 15 operative on an upper part or split glandring 16 bearing on a body of deformable packing 17 supported on a split-ring 18 resting on a ledge 5 in the bore.

The head assembly shown includes, also, inner casings I and I and each of these is supported individually on its respective cap 5 and 5", which are similar to cap 5, exceptin size.

The superimposed caps are fastened against lift by gangs of flange bolts 9.

When the casings are to be capped off each is roughly cut across on a line just below the top of its supporting cap (55-5) so that the next upper cap can be imposed without interference.

While each casing is severally supported by its cap the surrounding well space is sealed off by its respective packer set (15 17) and. this can be effectively jammed while the adjacent follower is exposed before application of the next higher cap.

Flow from the well is provided by a crown flange 20 bolted at 21 to the top cap 5", and having a nipple or flow pipe 22 of about the diameter of the innermost casing.

This multi-cap casing head is highly eflicient, of great strength, is practical and simple, and its packing, backed up by thefol- This casing is lower, holds against high gas pressure. It will be seen that the caps do not have a close lit on the casings but are of such bore size as to freely pass coupling collars of the relative casing. Any inner casing can be raised or lowered without disturbing the casings outwardly thereof. And the packer can be removed from the bore of a cap so that the slips can be inserted or removed while the cap is in place about the casing.

What is claimed is:

In a concentric casing head apparatus a plurality of separable. connected, superimposed cap units, each with an internal conical bore in their lower ends and grip slips therein to hang a respective casing. each cap bore adapted to permit passing of coupling collars of relative casing, and each having a packer assembly disposed above the slips in the caps and including an adjustable follower ring threaded from end to end and wholly screwed in its respective cap below the top plane of respective caps, the bottom of each superposed cap wholly overhanging the packer assembly in and being substantially coplanar throughout and flush with the next lower cap; each packer being readily accessible from the top bore of its cap in the absence of higher caps in the apparatus.

WILLIAM D. SHAFFER.

Images