# US 4,134,456 A · Sub-sea well heads

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- Number: US 4,134,456 A
- Document ID: US4134456A
- Status: Granted
- Kind: A
- Application number: 05/771,357
- Filed: 1977-02-23
- Granted: 1979-01-16
- Earliest claimed: 1976-05-12
- Assignees: Vickers-Intertek Limited
- Inventors: Kenneth Ball
- Web page: https://patentgrep.com/patent/US4134456A

## CPC

- E21B 41/06: Work chambers for underwater operations, e.g. temporarily connected to well heads
- B63C 11/40: adapted to specific work
- E21B 33/037: Protective housings therefor
- E21B: EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- B63C: LAUNCHING, HAULING-OUT, OR DRY-DOCKING OF VESSELS; LIFE-SAVING IN WATER; EQUIPMENT FOR DWELLING OR WORKING UNDER WATER; MEANS FOR SALVAGING OR SEARCHING FOR UNDERWATER OBJECTS (floating nets, floating slipways, or the like for recovering aircraft from the water B63B35/52)

## Abstract

A sub-sea well head comprising a connector and a christmas tree which is enclosed in a capsule is characterized in that a master valve is contained within a member forming the foot of the christmas tree, the member penetrating and being sealed into the bottom of the capsule and supporting the capsule, and in that the master valve is contained within a part of the member within the capsule.

## Claims

### Claim 1

Means for mounting a pressure resistent capsule and a christmas tree contained within the capsule to a sub-sea wellhead with minimum leakage paths from said wellhead into said capsule, said capsule being of a size permitting the entrance of personnel thereinto for performing operations on said christmas tree, said means comprising a unitary member at the foot of the christmas tree penetrating the lower wall of the capsule and having a first part within the capsule containing a master valve and a second part extending exteriorily beyond the lower wall of said capsule, means sealingly supporting said capsule on said unitary member intermediate the first and second parts thereof, and a connector entirely exterior of said capsule connecting said wellhead and the second part of said unitary member whereby all leakage paths from the wellhead to the interior of the capsule are eliminated except by way of the master valve in the first part of said unitary member.