What does the oil spill modelling show?

WesternAustralia

NorthernTerritory

Queensland

New South Wales

Victoria

SouthAustralia

Planning Area

Well location

0 500 Kilometers1000

Perth

Adelaide

Brisbane

Sydney

Canberra

Melbourne

Hobart

Darwin

The map in the top right-hand corner is shown in our EP. However, it does not represent what a single spill would look like, nor the area it would affect. To identify all possible locations which could be affected in the highly unlikely event of an oil spill, we use computer-simulated modelling. The results are used to define the geographical area which we use in our risk assessment and response planning — a planning area, as shown on the larger map.

To make sure we have planned for anything that could possibly happen, regardless of how unlikely it is, we form a single map by superimposing 100 different variations of a worst-case spill to generate a large planning area which we have called the Risk Environment that May Be Affected (Risk EMBA).

The modelling assumes that every piece of safety equipment on the rig fails, and nothing is done to stop the leak, contain or disperse the oil for a hundred days. In case of a real oil spill, we would respond immediately. Also, the oil volumes are equivalent to the flow from an unrestricted open hole. In practice the hole would always have blockages caused by the drill pipe and blow-out preventer.

Appendix 7.1 Oil spill modelling report.