The biggest development in the North Sea for a decade has attracted industry attention as one of the most innovative projects to date. Seven economically marginal fields with different owners and different hydrocarbons have been brought together to create the £1.6 billion Eastern Trough Area Project (ETAP). Innovation on both technical and commercial fronts has been created by an unprecedented level of cooperation between companies. This paper outlines the basis of the project and the approach adopted to its formulation which resulted in novel technical and commercial solutions.
The challenge for today's North Sea, with ever decreasing field size, is to reduce development costs/bbl to acceptable levels and to do this through working the two available levers: cost and the number of barrels. The ETAP solution to reduce cost and add barrels is to combine small fields into a single project with development cost/bbl similar to a single giant field, but with the reservoir risk mitigation inherent in accessing multiple independent reservoirs. This approach created many hurdles, both technical and commercial, and has stimulated innovative solutions.
Technical hurdles include the need for long distance sub sea multiphase tiebacks in excess of 35 Km which have innovative chemical control and multiphase metering. Commercially, the project presented a major challenge as all parties agreed that a conventional unitisation of all the fields into unified ownership interests was neither practical or desirable in light of the range of fluid types and reservoir uncertainty. Accordingly a structure was developed to a) share Capital and Operating costs equitably, b) provide for production rights and production allocation and c) encourage full utilisation of the shared facilities.
The significant cost savings needed to make ETAP viable were largely achieved in the conceptual design phase by designing shared and centralised facilities for both oil and gas field management. In the current project execution phase additional cost savings are being delivered through further application of "alliance contracting" with the contractors for design, fabrication and installation of the facilities and for the development drilling.