Tether Tension Variation of Tension Leg Platform (TLP) due to Random Waves

Since petroleum exploration has shifted into deep water region, Tension Leg Platform
(TLP) becomes one of the alternatives of floating platform. TLP is more economically
feasible over jacket platform because its construction cost does not linearly increases as
water depth increases. TLP allows movement in surge but not in heave. The presence of
tethers components and the excess buoyancy of hull keep the TLP in tension. In this
project, the response of TLP in surge, heave and pitch are studied. The study of tether
performance is completed by analyzing the tension variation along the tether member.
The dynamic analysis includes Pierson-Moskowitz Spectrum, Time Series and response
of surge, heave and pitch when they are subjected to random waves. The result obtained
from surge calculation is used to determine the tether tension variation. Then, graphs are
plotted from the result obtained. Besides that, model testing was also conducted. The
purpose of model testing is to observe the trend and the response of the structure when it
is subjected to regular waves. From dynamic analysis and model testing activities, it is
confirms that TLP exhibits more response surge direction than heave due to the presence
of tethers component. As conclusion, the TLP is kept floating and stable due to the
presence of tether members which restrains its motion in heave direction.