DP systems for offshore vessel positioning in deep water

Abstract

Current industry practices and the suggestions from the literature are that offshore oil exploration and production activities will move into deeper water further from shore. To achieve that, dynamic positioning systems are indispensible. In the past 5 years, there has been a dramatic increase in the number of offshore installations equipped with DP systems.

This thesis is focused on comprehensive characteristics, utilities, risk analysis and future trends regarding positioning systems in the offshore oil industry, and figures out the most suitable methods for keeping an offshore installation on location (traditional anchor mooring system, lightweight mooring system, dynamic positioning system). Specifically, this thesis emphasizes on the offshore dynamic positioning system. This method will be investigations to improve the accuracy and reliability of different types of rigs and vessels, as well as improving the safety and efficiency of DP operations.

Safe operations of the dynamic positioning of offshore drilling units and support vessels are dominated by two parameters, the resistance against drift-off from position and the robustness of position recovery. The operational facts tell us that DP vessels’ loss of position during operations is not rare. Effective ways will be illustrated by evaluating the two parameters and improve the safety accordingly. HAZOPs and FMEA risk analysis methods will be used to evaluate the reliability of the system．