Extreme Vertical Deepwater Current Profiles in the South China Sea, Offshore Borneo
This paper details a study of extreme oceanographic currents at deepwater locations offshore Borneo in the South China Sea. With the global demand for oil and gas set to rise steadily over the long-term, oil and gas operators are ever more exploring deeper waters in search of reserves. Often, these finds are economically marginal and challenging from an engineering perspective. Offshore Borneo is a typical example of this, where one such challenge is the prediction of extreme current speeds. Indeed, currents in deepwater are more complex and less constant with depth. As a consequence, the vertical profile associated to an extreme event is integral in the design and safe operation of deepwater facilities. Until recent exploration little measured full-depth deepwater current data has been available. With new datasets for multiple offshore locations, current speeds through the water column are approximated using Empirical Orthogonal Functions (EOFs) and their extreme profiles derived using the inverse First Order Reliability Method (FORM). These profiles are then compared with consideration of different types of current events and used as a basis to formulate idealised deepwater design vertical current speed profiles for locations offshore Borneo that are application specific.