Innovative approach for oil production based on subsea tunnels and caverns

A feasibility study has been done for comparing a concept based on subsea tunnels and caverns with traditional development strategies for offshore oil fields. A realistic oil field off the shore of northern Norway has been studied. The concept includes 2 or 3 tunnels descending from the terminal facility on land to a base station at the low point. From the base station, parallel tunnels will be TBM-bored to the location of large production caverns that need to be established for drilling equipment and operation facilities. The study suggests that the concept is feasible and viable compared to traditional developments. The costs are competitive for fields in the range of 30 km from the shore, as in the case studied. Several challenges need to be met for a robust solution, but these are all considered being within the range of technology development. The concept reduces the environmental risk to a minimum, and provides a solution to improve the utilization of the oil field better than traditional solutions.