Mating of the Topsides Onto the Lower Hull: P52 Semi-Submersible

Since the early 80’s, Technip has developed a special technology, called the UNIDECK® concept, for the float over installation of topsides. This method has been used for platform installations in benign areas such as the Persian Gulf or Far East Asia and in particular, in difficult sea conditions such as the long period swells occurring in West Africa. Based on its extensive experiences for topsides’ float over installation over more than twenty years, Technip has recently adapted this proven technology to semi-submersible units for their assembly by a mating operation of the topsides onto the lower hull. This paper gives an overview of the technical aspects involved in a mating operation of two floating units through a description of the operation performed for Petrobras’ P52 semi-submersible in June 2006.