Abstract

Mobile offshore drilling units (MODU), such as semi-submersibles, usually employ multiple azimuth thrusters to maintain their position during drilling or exploration. However it is reported that there is a considerable degradation compared with its open water performance. This reduction results from thruster interactions with the hull, current and other thrusts. Because it is essential for an accurate evaluation of the dynamic positioning capabilities (DP), researches have been performed to understand and quantify the thruster interaction itself. However these thrusters are often used as a self-propulsion device. In that case, thruster interaction affects the overall power, so the transit speed would be decreased. In the present study, method to improve an effective thrust during the transit operation by steering individual thruster considering the interaction was studied.

Keywords:
thruster, efficiency, foreaft thruster, simulation, upstream oil & gas, empirical formula, thruster interaction, calculation, interaction, degradation
Subjects:
Drilling Equipment, Offshore drilling units
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2015. International Society of Offshore and Polar Engineers
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