| Abstract | During drilling operation, the motion of a drilling rig should be predicted for the safety assessment under various ocean environmental conditions. However, it is not easy to analyze its motion because an analysis target which includes a BOP (Blow-Out Preventer), risers, and a riser tensioner system is fully coupled and connected each other. The BOP and the bottom of the risers are connected to each other by a ball joint. The top of the risers called a telescopic joint is connected with tension rings of the riser tensioner system by a ball joint. The WRT (wireline riser tensioner) system, which is composed of the tension rings and several hydraulic and pneumatic cylinders, is used to compensate the heave and yaw motion of the drilling rig. Between the telescopic joint and the BOP, several pieces of drilling risers are used to connect them. In this study, we developed a dynamic analysis program called SyMAP (SydLab’s Multiphysics Analysis Program) considering flexible effects of the risers. For this, the concept of multibody dynamics is introduced and used to simulate the motion of multiple bodies connected by various types of joints. And then, a FE (finite element) method based on the ANCF (Absolute Nodal Coordinate Formulation) is adopted to consider flexible effects of the bodies such as the risers. To evaluate the effectiveness and applicability of the developed program, it was applied to the dynamic motion analysis of the drilling rig connected with the risers. As a result, maximum motions of the drilling rig and bending moments of the riser were calculated under ocean environmental conditions according to various significant wave heights and mean wave periods. |
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| Publication Date | 2016-09-29 |
Seung-Ho Ham, Myung-Il Roh, Hye-Won Lee, Jung-Woo Hong, "Dynamic Motion Analysis of a Drilling Rig Connected with Flexible Risers based on Flexible Multibody Dynamics", Proceedings of SUTTC(The Society for Underwater Technology Technical Conference) 2016, Beijing, China, 2016.09.26-30