Permanent, large, forged or cast steel fitting on the surface of the ground on top of the well. It consists of the larger, lower casinghead that seals off the annulus between the casing strings and contains the casing hangers for the top of the casing strings.
All manufacturers propose fairly similar versions of compact wellhead. The heads are made up of one or two components serving as casinghead housing, casing spool and tubing head. The compact (on three-stage) configuration is screwed or welded onto the surface casing and will then accommodate the tubulars equipped with the corresponding hanger system.