Fluid Structure Interaction Study on Dynamic Response of a Capped Drilling Riser Filled With Mud

Abstract

In the offshore drilling, during emergency disconnect scenario the drilling operation must not be maintained and forced LMRP disconnect procedure takes place [1,2]. Such procedure allows drilling mud to interact with seawater. The paper presents hydrodynamic behavior of a drilling riser when mud is retained and not interacted with seawater. A two-way coupled fluid-structure interaction (FSI) model between a simplified drilling riser structure and mud fluid was studied through techniques of computational fluid dynamics (CFD). The volume of fluid (VOF) hydrodynamics model was used with commercially available software STAR-CCM+ [3]. A 3D finite element (FE) model of a drilling riser was created in FE software ABAQUS [4] to determine the stress and deflection of structural parts of the model due to hydrodynamic loads. In the model, the compressibility [5] and non-linear behavior of the mud was included. The dynamic frequencies of the two domains and possible resonance of the coupled system were investigated. The aim of the study was to verify the dynamic behavior of a riser system with a drilling mud enclosed within the system. The authors of this paper know no similar study of such a problem.