US 5,771,974 A · Test tree closure device for a cased subsea oil well

Abstract

In an offshore oil installation, the closure device (40) of a subsurface test tree placed in the blowout preventer stack on the seabed is made in a modular manner. More precisely, the closure device comprises a plurality of lengths (54,56') suitable for being placed in arbitrary order between a top element (50) and a bottom element (52). This arrangement makes it possible to place the connector (46) between the total shutoff valves (26) and the partial shutoff valves (28) of the blowout preventer stack, and to place the valves (42,44) of the closure device (40) in a closure length (54) that is situated beneath the partial shutoff valves (28). The two total shutoff valves (26) can thus be actuated regardless of the type of blowout preventer stack that is used.

Claims20

Dependent claims

A subsurface test tree closure device suitable for being placed in a test tree for a cased subsea well, inside a blowout preventer stack of the well which includes two total closure valves placed above two partial closure valves, and a base below the partial closure valves, comprising:

a bottom element including an anchor part for anchoring the device to said base;
a top element;
a connector, said top element including at least a top portion of said connector;
at least one closure length including a set of valves;
at least one tubular connection length;
and
dismountable assembly means for connecting either one of said lengths to said connector and the other one to said bottom element, and said closure length to said tubular connection length.

4 more elements

Dependencies are inferred from the claim text.

Test tree closure device for a cased subsea oil well

Life of this patent

Test tree closure device for a cased subsea oil well

Life of this patent

Abstract

Claims20