Oil & Gas – Pipelines & Landfalls
Europipe Development Project – Landfall Tunnel Project – Germany

Client
Statoil Den norske stats oljeselskap a.s

Joint Venture Landfall Tunnel (HochTief AG, Bohlen & Doyen GmbH)

Operator
Statoil

Project Location
Germany

IMPaC’s Services
32,000 hours

Investment
300 million USD (landfall)

Year
10/1991 – 02/1995

IMPaC’s Scope
Development of installation & routing concepts
Authority engineering
Detailed design & engineering
Stress analyses
Project management consultancy
Installation engineering & supervision

Back to overview

The 620 km long 40" gas pipeline runs from the 16/11-E platform to receiving facilities in Germany. The pipeline design pressure is 156 barg. The route crosses nearshore shallow water areas with the landfall located at the north-west German Waddensea coast. The entire nearshore and landfall areas are highly protected by environmental legislation.

IMPaC became involved in the very early stages of the project and significantly contributed to the development of routing and installation concepts and the associated authority engineering.

In cooperation with the client and the responsible authorities the concept of a 2.5 km landfall tunnel, which crosses the dry falling mudflat and the main dyke was selected. The tunnel having a diameter of 3.5 meters was constructed by the telescopic pipe jacking method. The connection to the offshore pipeline was facilitated by a circular offshore Tie-In Chamber, which also served as an anchor point for the pipeline. During the project the Client chose to install two pipelines into the tunnel instead of a single pipeline as per the original planning.

IMPaC’s task was the design and engineering of the Tie-In Chamber including its connection to the tunnel. Also part of IMPaC’s scope was the engineering for the pulling of the twin pipe-string into the tunnel from the shore to the Tie-In Chamber. This included comprehensive stress and buoyancy analyses for various construction situations and load cases. Furthermore, throughout the entire project various general project management and engineering services, on-site supervision and related services were provided.