Prediction and analysis of the efficiency of the shuttle tank collection method to collect wrecked residual oil

Abstract

In the “Prestige” oil spill, REPSOL proposed a new shuttle tank collection method for wreckage oil collection; the proposed method is effective for wreckages located more than 3000 m underwater. This method was effective for the Prestige incident. To determine the efficiency of this method, a model reflecting the internal situation of the oil tank was analyzed and fitted as a basis for establishing the relationship between the instantaneous collection speed and different parameters. Computational fluid dynamics (CFD) simulations were performed using a Volume of Fluid (VOF) model of the collection process. The influence of various parameters on the collection efficiency was investigated. An efficiency prediction model without viscosity reduction was established. The results showed that the collection efficiency was mainly affected by the outlet size and oil depth inside the tank. The collection speed reached 22.33 m³/h at an oil depth of 10 m and an oil outlet radius of 0.5 m. The instantaneous collection speed prediction model was fitted based on the dynamic flow analysis results. Furthermore, the prediction model proposed in this study can contribute to improvements in the efficiency of this method and the design of devices.