The tubing head is the top spool on a surface wellhead assembly. It is installed after the last casing string to provide a load shoulder to support the tubing string and a seal bore for the tubing hanger or production casing/tubing annulus seal. When the well is completed, the tree is installed on top of the tubing head with a tubing head adapter.

“Wedge locking” of bowl protector, BOP test plugs, and tubing hangers is eliminated, Seal bore is less likely to be damaged during drilling, It’s more economical to recondition after abandon.