Current Profile Estimation for a Moored Floating Structure

Abstract

Stationkeeping operations for offshore vessels (drillrigs, drillships, construction and intervention vessels, PSVs, etc.) are essential for offshore filed development and oil and gas production. Short-term subsea operations are very often to be conducted. Current speed influences the safety of the subsea and marine operation. Though various commercial sensors can be applied to detect the current speed at a specific location, such as the acoustic Doppler current meter and the electromagnetic current meter, it will be costly to install them in some temporary projects. The potential of losing their signals and measurement error also exist.

That's why the innovative approach of combining the TAPM system and the current estimation comes up. In this thesis, the focus is to estimate the 2D on-site current profile with existed measurements from a TAPM system. This includes use of all available, possibly redundant, measurements in the dynamics positioning system, winch monitoring systems, riser management system, etc. The current profile estimation could increase the safety of short-term subsea operations without extra costs.