A Resourceful Industry Lands the Serpent
Authors: Langley Diane 
Published: February 2015

In 1997, Norsk Hydro cast a line with wildcat well No. 6305/ 5-1 and hooked a big fish even for the North Sea. In 2000, the industry stepped back and gave pause to the enormity of the undertaking. It had become clear that the Norwegian serpent, Ormen Lange, would be a heavyweight in all respects. The project takes its name from the ship of Viking King Olav Tryggvasson.

Charting the course to landfall is a group of star licensee/operators—Hydro, Shell, Petoro, Statoil, Dong, and ExxonMobil. The giant serpent, stretching across four North Sea blocks, is destined to become a major European gas source, covering 20% of U.K. gas requirements for 40 years. The U.K. gas market is the largest in Europe, with annual consumption of 3.9 Tcf. From geologic and climatic perspectives, main subsea installations and pipelines will be subjected not only to mountainous terrain created in the scar area of the Storegga avalanche slide, but also to cold polar currents driven by the Gulf Stream, generating some of nature’s most brutal forces. Water temperatures on the seabed are below freezing for most of the year—perfect conditions for hydrate development. The ocean surface is thrashed by fierce winds and waves.

Beyond these challenges, Ormen Lange is seen from Hydro’s vantage point as three concurrent projects—development of the reservoir with templates and pipelines to shore, design/construction of the Langeled pipelines (one with 42-in.-diameter and another with 44-in.-diameter pipe), and construction and operation of a processing plant. This intensely faulted reservoir (one study reports that more than 1,000 faults have been interpreted and included in simulations) is the second-largest gas discovery on the Norwegian shelf (the Troll field is the largest) and will be Europe’s deepest subsea development. Ormen Lange will contribute to a doubling of Hydro’s gas exports by the year 2010, making Norway the world’s second-largest gas exporter. The project is the largest in Norway’s history.

With main gas reserves located in the Vale formation, drilling has already confirmed resources of 11 Tcf of gas; production is planned at 2.5 Bcf/D of gas and 53,463 B/D of condensate will be stored. The climatic and oceanographic conditions in the region of the find present severely challenging conditions, and forces created by wind and waves are as challenging as any other deepwater project. Some long-time veterans of the North Sea development call Ormen Lange the most challenging offshore project ever. In cooperation with internationally recognized Norwegian expertise, extensive studies have been conducted regarding the stability of seabed masses and slide safety along with future natural conditions, including potential tsunamis, and conditions resulting from project activities.

The associated subsea-export-pipeline project is one of the largest undertaken by the industry. Gas will be transported more than 1200 km from Nyhamna via the Sleipner platform in the North Sea (Fig. 1). Total investment cost is estimated at U.S. $10.2 billion, including $7.2 billion for development and $3 billion for the transport system. A hotel built for workers at Nyhamna, where the gas-processing plant is being built, is larger than any other hotel in Norway (three times larger than the Oslo Plaza Hotel).