Method and apparatus for subsea wellhead encapsulation

摘要

A BOP stack encapsulation system has dual partially hemispherical dome sections which are each supported and guided for linear movement to open and closed positions relative to base plate. The dual containment domes are moved from open positions to closed and hermetically sealed positions about a BOP stack responsive to sensing BOP leakage or a dangerous pressure condition and are controllable from a remote location. When both containment domes are closed they develop concentrically arranged dual hermetically sealed spaces that enclose the BOP stack and capture any leaked fluid and pressure. Captured well fluid constituents can be bled from the internal spaces of the concentric encapsulation domes as desired.

主权项

1. A method for containing well fluid leakage from a sub-sea well having a blow-out preventer system (BOP) connected with a riser conduit and being located at the sea bed, comprising:
positioning primary and secondary encapsulation domes near said BOP, each of said primary and secondary encapsulation domes having a pair of quarter dome sections being positioned on opposite sides of the BOP and being moveable linearly and substantially horizontally between open positions with said dome sections substantially horizontally spaced from one another with the BOP between them and closed positions with said quarter dome sections moved linearly and substantially horizontally into contact with one another and establishing sealed engagement with one another, said primary encapsulation dome, when closed, encapsulating the BOP and establishing sealing with said riser conduit, and said secondary encapsulation dome, when closed, encapsulating said primary encapsulation dome and establishing sealing with said riser conduit; maintaining said primary and secondary quarter encapsulation dome sections in substantially horizontally spaced open positions during normal well drilling and production activity; and moving said primary and secondary quarter encapsulation dome sections from said substantially horizontally spaced open positions to said closed positions responsive to detection of a predetermined abnormal well condition.