The casing head is the lowest part of the wellhead assembly and is connected to the surface casing string. It supports subsequent drilling wellhead and completion equipment.
Casing Heads provides for attachment to the surface casing string, Supports blowout preventers while the hole is drilled for the next casing string. Also, provides for suspending and packing off the next casing string and outlets for annular access. It’s useful for testing BOP’s while drilling.