Apparatus and method for free-fall installation ofan underwater wellhead

摘要

An apparatus and method for pre-installation of a petroleum wellhead on the seabed. The apparatus includes two principal components: a wellhead ( 1 ) and a ballast tube ( 9 ). The wellhead includes a tube in which are fixed guide fins ( 3 ) and structural fins ( 8 ). The ballast tube ( 9 ) includes a tube with a holding member ( 12 ) for its recovery after the wellhead ( 1 ) has been fixed on the seabed. The ballast tube ( 9 ) is placed inside the wellhead ( 1 ) and the assembly is launched towards the seabed, being embedded in it by the inherent weight of the assembly. After the wellhead ( 1 ) has been fixed, the ballast tube ( 9 ) is raised to the surface.