CARISIMA: A Catenary Riser/Soil Interaction Model for Global Riser Analysis

Steel or titanium catenary type risers may provide cost effective alternatives to flexible risers, particularly for deeper water (>300 meters). Existing analysis tools for riser response have proven reliable for most types of risers. However, in the area where catenary risers are resting on the seafloor, existing models for riser/soil contact are too simplified to capture the complexity of the interaction. Some of the key findings of earlier work are that the fatigue life predictions at the touchdown area are sensitive to the FEM modelling, fatigue accumulation procedures and, in particular, the soil model. Hence, an important step forward in improving riser analysis tools is to improve the riser/soil interaction model. This issue was the key objective of the CARISIMA JIP. This paper gives an overview of the main activities in the CARISIMA project.