This paper presents the experience accumulated by Saipem in modelling the deep water sealine installation by using the J-lay method, mainly as a result of the Blue Stream Project. This Project implied the installation of two sealines in the Black Sea at a world record water depth of about 2150 meters by using the new J-lay system on SSCV Saipem7000. The paper shows the results of the studies made in order to properly model the installation of a deep water pipeline by J-lay. These studies aimed at the development of an adequate installation analysis model and tools (specially developed three-dimensional FEM analysis inhouse program), and at the definition of the installation analysis methodology. Such methodology includes the analysis of the effects of vessel displacement (forward, backward, and lateral) with respect to the target (reference) position, of seabed slope and real profile, and also the dynamics effects due to environmental loads.
The offshore industry is moving into more hostile and deeper waters with exploration and oil field development and with gas trunklines crossing deep seas, as the Mediterranean Sea and recently the Black Sea. Saipem Group is in the forefront of such challenges by performing successfully the Blue Stream Project, undoubtedly the most significant deep water pipeline project ever attempted because of the difficulties in terms of design, construction, organization and logistics. Such demanding Project required important engineering efforts for both design and installation engineering, including the development of new design methodologies and tools, especially for the ultra deep section of the pipeline installed by using the new J-lay system on SSLV Saipem 7000. This paper presents the experience accumulated by Saipem, mainly as a result of the Blue Stream Project, in modelling the deep water sealines installation by using the J-lay method.