Thin Oil Films – Properties and behaviour at sea - Laboratory studies and oil weathering predictions

Abstract

The Petromaks 2 project "Formation and behaviour of thin oil films and evaluation of response methods including HSE", in the following short "Thin oil films" has the objective to achieve new knowledge more efficient and safe oil spill response operations for releases of condensates and light crude oils that may lead to thin oil films on the sea surface.

Main objectives are: 1. lncreased understanding of the formation and behaviour of thin oil films 2. Assessment of the potential human exposure to volatile compounds 3. Refined processes in oil trajectory models in order to give more reliable predictions of the lifetime and behaviour of thin oil films and to assess the efficacy of response options.

This report addresses objective 1 and summarizes the results from the laboratory experiments to study weathering properties and characteristic of surface residues from thin oil films formed under cairn weather conditions (1-2 m/s wind). The SINTEF Oil Weathering Model (OWM) was used to predict oil weathering properties with a standard set of thin oil film scenario (<200 µm) at 2/13 °C under cairn condition (2 and 5 m/s). Data and observations of thin oil films in the laboratory were compared and discussed with the OWM predictions of the condensates (Alve, Ormen Lange, Marulk, Atla and Skarv), the light crude oils (Gjøa and Vale), including a reference crude oil (Statfjord C Blend).