Safety system for oil and gas drilling operations

摘要

A sub-surface safety system for hydrocarbon drilling operations is provided and includes at least one casing within a wellbore that extends into a first portion of a formation from the surface of the formation. A shut-in device is positioned in the casing so as to be below the surface of the formation. The well shut-in device defines a device passageway and is operable to sever a drill string extending through the device passageway and form a barrier in the device passageway that restricts wellbore fluids below the barrier from migrating up the casing to the surface.