1. Field of the Invention
Embodiments of the present invention generally relate to a subsea well. More particularly, embodiments of the invention relate to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well.
2. Description of the Related Art
After the production of a subsea well is finished, the subsea well is closed and abandoned. The subsea well closing process typically includes recovering the wellhead from the subsea well using a conventional wellhead retrieval operation. During the conventional wellhead retrieval operation, a retrieval assembly equipped with a casing cutter is lowered on a work string from a floating rig until the retrieval assembly is positioned over the subsea wellhead. Next, the casing cutter is lowered into the wellbore as the retrieval assembly is lowered onto the wellhead. The casing cutter is actuated to cut the casing by using the work string. The cutter may be powered by rotating the work string from the floating rig. Since the work string is used to manipulate the retrieval assembly and the casing cutter, the floating rig is required at the surface to provide the necessary support and structure for the work string. Even though the subsea wellhead may be removed in this manner, the use of the floating rig and the work string can be costly and time consuming. Therefore, there is a need for an improved method and apparatus for subsea wellhead retrieval.
USPTO Backgrounds
USPTO Backgrounds