Statoil ASA: Making Norway’s largest oil refinery safer.

Statoil ASA is a Norwegian multinational oil and gas company, headquartered in Stavanger. Our client is the largest operator on the Norwegian Continental Shelf, with 60% of the total production.

Following recent improvements and modifications to the Mongstad plant and infrastructure, Statoil needed to upgrade an environmental risk and oil spill emergency preparedness analysis. Since this analysis had been performed, oil spill simulation software had been improved for more accurate results. Furthermore, environmental resource data for the area had been updated, and Statoil had developed highly detailed acceptance criteria for environmental damage. The basis for the analysis was altered and would likely generate different results.

Statoil asked us to help enhance its risk understanding, put in place the latest safeguards to minimise risk to life, property and the environment and meet external demands. It is an authority requirement that operators keep risk analyses up to date with regard to activity level and accidental discharge potential.

We divided our role into two main parts.

1. Providing an environmental risk analysis to investigate all hazards at the plant that could result in environmental damage, including emissions to air, discharges to ground and spills to sea.
2. Conducting an oil spill emergency preparedness analysis to evaluate the emergency preparedness organisation in place, barriers and technical measures, as well as update the oil spill emergency preparedness analysis accordingly.

We were commissioned to identify all hazards to the environment and categorise each according to Statoil’s guideline for classification of environmental risk. Based on an evaluation of the emergency preparedness organisation, barriers and technical measures, we also updated the existing oil spill emergency preparedness analysis.

To gain the necessary insight into all process streams, equipment, chemicals, former incidents and routines, we held a series of multidisciplinary workshops and inspections with operating personnel from each investigated area. Based on these workshops and review of relevant documentation, the plant hazards were mapped and compared to Statoil’s tolerance criteria for environmental risk. Hazards that could result in large quantities of oil spill to sea were thoroughly investigated using methodologies from offshore environmental risk analyses.

To produce a detailed image of the oil’s impact on the sea, we combined weathering data with historical wind and currents data. Scenarios were simulated using the oil spill contingency and response software, OSCAR. This allowed us to investigate the oil’s interaction with the coastline, drift patterns and interaction with environmental resources.

We then categorised the identified hazards with and without oil spill emergency preparedness measures. This enabled us to quantitatively demonstrate the effect of emergency preparedness on the environmental risk.

The oil refinery at Mongstad is the largest facility of its kind in Norway, with an annual capacity of nearly 12 million tonnes of crude. The plant is situated north of Bergen and receives crude oil from the North Sea, while wet gas is transported through pipelines from the process facility at Kollsnes. Outputs range from petrol and diesel oil to jet fuels and other light petroleum products, which are exported mainly to continental Europe.

By assessing all the potential hazards around how the refinery operated and how it was managed, we helped ensure that Statoil’s management and operational teams could handle an accident effectively and safely. Ultimately, our collaboration enabled Statoil ASA to further improve risk management of its large facility.

“The work and openness of Statoil to ensure that a robust approach to safety is in place across its refinery operation provides industry and the local community with confidence of the company’s capability and determination to reduce and manage risk.”

Are Børjesson

Senior Environmental Consultant, Statoil ASA