Abstract: 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.

Abstract: A petroleum well intervention winch system includes a high pressure confining housing for a drum for a rope to a tool string. The pressure confining housing has a connector with an aperture for the rope to a top of a tool string gate chamber on vertical bore BOP valves on a wellhead on the petroleum well. The rope runs through the aperture via a capstan to the drum. The capstan is driven by a first motor through a first high pressure proof magnetic coupling across a wall of the housing. The drum is driven by a second motor through a second high pressure proof magnetic coupling across the wall of the housing. The capstan is subject to a load tension from the rope and is provided with a hold tension on the rope from the drum. The second motor exerts a constant hold tension on the rope via the drum.

Abstract: A petroleum well intervention winch system includes a high pressure confining housing for a drum for a rope to a tool string. The pressure confining housing has a connector with an aperture for the rope to a top of a tool string gate chamber on vertical bore BOP valves on a wellhead on the petroleum well. The rope runs through the aperture via a capstan to the drum. The capstan is driven by a first motor through a first high pressure proof magnetic coupling across a wall of the housing. The drum is driven by a second motor through a second high pressure proof magnetic coupling across the wall of the housing. The capstan is subject to a load tension from the rope and is provided with a hold tension on the rope from the drum. The second motor exerts a constant hold tension on the rope via the drum.