Namibia coast modelling study

PRDW’s scope of work included the following:

• Provide a description of the metocean conditions, such as winds, ocean currents, coastal features and bathymetry in the licence area;
• Model the dispersion and concentration of drilling mud and cutting discharges associated with the drilling operation to determine the thickness and extent of deposited material on the seabed;
• Model the trajectory, extent and fate of an oil spill due to a small operational spill on the water surface at the drilling unit;
• Model the trajectory, extent and fate of an oil spill due to a large blow-out event at the wellhead on the seafloor.

The oil spill and drill cuttings modelling was performed using the MIKE by DHI Oil Spill and Particle Tracking models, respectively. The wind forcing for the models was extracted from the National Centers for Environmental Prediction (NCEP), while the currents were extracted the Hybrid Coordinate Ocean Model (HYCOM).

A number of stochastic simulations were performed to model a wide range of expected wind and current conditions. The drill cuttings model results included the extent and deposition thickness on the seabed, while the oil spill model results included the probability of surface oiling and minimum travel time to oiling.

The model results were provided to a Marine Faunal and the Fisheries Specialists to enable the impacts to be assessed.