METHODS FOR CONDUCTING A SUBSEA WELL INTERVENTION, AND RELATED SYSTEM, ASSEMBLY AND APPARATUS

摘要

A method for conducting a subsea well intervention at a subsea well, and a related system. In particular embodiments, an assembly is provided comprising a wireline drum pressure container unit, a lubricator package having a lock chamber tube enclosing a tool string and having at least one valve in a vertical bore, and a connector used to connect the assembly to a well control package on a well head of the well. In such an embodiment, the method can include displacing well fluid in a cavity between the valve of the lubricator package and a valve of the well control package, using a clean fluid, while the valve of the lubricator package is closed. The assembly can then be disconnected from said well control package at the connector and retrieved to the surface, whereby contamination of seawater due to disconnection can be reduced or minimized.