An Innovative Oil Pollution Containment Method for Ship Wrecks Proposed for Offshore Well Blow-Outs

In the aftermath of the PRESTIGE disaster, an innovative system for the prompt intervention on oil pollution sources (primarily ship wrecks) at great depths was conceived at the Joint Research Center of the European Commission. This system, with some re-engineering, could also serve for collecting oil and gas leaking after an offshore well blow-out and could constitute a reference method for prompt intervention on deep water oil pollution sources like ship wrecks and blown-out offshore wells. A large fabric dome, solidly anchored at the sea bed, covers entirely the pollution source and channels the leaking oil to a large open bell-shaped reservoir just under the sea surface so as not to be affected by the waves. Oil occupies the upper part of the bell and is periodically recuperated by a shuttle tanker while water escapes from the open bottom. The buoyancy of the reservoir keeps the whole system in tension. The concept was validated and optimized through detailed engineering, laboratory experiments and numerical simulations performed by a consortium of European institutes and industries in a dedicated collaborative research project called DIFIS (Double Inverted Funnel for the Intervention on Shipwrecks). The project resulted in a light, modular and easy to deploy system design. Such a system, suitably dimensioned and re-engineered to take account the gas flow, could also be used to cover the wellhead area so as to collect all leaking oil and gas until the implementation of the relief drilling. The present paper outlines the DIFIS system and elaborates on its advantages and risks in containing oil well blow-outs.