<p>Drilling risers are key components in the offshore oil exploration and are present in most of the well construction phases (drilling, casing, cementing and completion). Mobile offshore drilling units can operate in different sites exposed to a range of environmental loadings and water depths. For this, global riser analyses based on the finite element method are performed to assess the system feasibility and operating envelopes. In harsh environment and ultradeep water scenarios, the riser running/retrieving operation is one of the most critical due to top-angle limits and riser stress as result of either contact with the diverter housing / substructures or boundary condition with the gimbal-spider (API-RP-16Q, 2017, ISO 13624-1, 2009).</p><p>The use of beam/hybrid elements is satisfactory for modelling the riser global response, however it may lead to result uncertainty in terms of local response associated with complex geometry, stress concentration and contact modelling (DNVGL-RP-F203, 2017, DNV-ST-F201, 2018, ISO 13628-7, 2005). Therefore, this work aims to assess those limitations and simplifications of global riser analysis for the drilling riser running/retrieving operation. This assessment was done through a comparative study based on global and local finite element analyses. The results show convergence and divergence aspects between both approaches, thereby, conclusions and recommendations are drawn to the use of global modelling for such operation assessment.</p>

Comparative Study of Drilling Riser Running/retrieving Analysis Methodologies

Paper Proceedings: https://asmedigitalcollection.asme.org/OMAE/OMAE2021/volume/85116

OMAE 2021

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