| 摘要 |
<p>A method and apparatus for drilling subsea wells is provided. A subsea shut off device including ball gripping mechanisms is latched to a template at surface. Drilled in casing can be suspended from the device at any position using the gripping mechanism so that the device is run to the sea floor on the casing string. The casing string is drilled into place and converted into a riser. This is all done on a single trip to speed up the operation and reduce the risk. The casing string is captured and sealed within the subsea shut-off device after installing and spacing out a surface BOP. For the event when emergency disconnection is required, dual shear rams in the device cut the casing and seal in the well. The system then allows a conventional subsea reconnection of the riser.</p> |
