US Patent 10081986 Subsea casing tieback

Techniques and systems to couple a high pressure casing string to a blowout preventer or a subsea shut-in device. A device includes a locking mechanism configured to interface with a terminal end of a casing string of an offshore platform to couple the device to the terminal end of the casing string. The device also includes a sealing mechanism configured to fluidly seal an area around the terminal end of the casing string, wherein the locking mechanism and the sealing mechanism are disposed at separate positions along a vertical orientation of the device.