Ormen Lange - an integrated study for safe field development in the Storegga submarine area

Great effort has been undertaken to investigate potential geohazards in relation to the development of the Ormen Lange gas field offshore Mid-Norway.

The field is located in the scar left after the giant, tsunami-generating Storegga Slide, which occurred roughly 8200 years ago, and the slide risk has consequently received particular focus. The studies have been multi-disciplinary in character, and have involved a number of companies, universities, and research institutions. The results of the project led to a significant advance in the understanding of the Storegga Slide in particular, and submarine slope instability in general, and played an important role in the approval of field development by Norwegian authorities.

This book comprises 26 individual contributions representing the wide span of topics addressed in the project. The main scope is to provide a state-of-the-art report on geohazard investigations in a high latitude continental margin setting. Most of the data and results published in this book would not have reached beyond the confidential report stage unless the license partners of the Ormen Lange license had agreed that this information deserves a wider audience.

• Multidisciplinary and covers most themes treated in slope stability studies prior to the field development phase
• Provides a link between basic research and applied geohazard studies, with direct relevance for risk evaluation in relation to field development activities, such as pipeline design, drilling of wells, structure foundation etc.
• A state-of-the-art report on geohazard investigations in a high latitude continental margin setting in relation to field development activities

Geologists, geophysicists, geochemists, explorationists

1. Ormen Lange - an integrated study for the safe development of a deep-water gas field within the Storegga Slide Complex, NE Atlantic continental margin (A. Solheim et al.).
   2. Explaining the Storegga Slide (P. Bryn et al.).
   3. Influence from "Ocean Weather" on near seabed currents and events at Ormen Lange (G. Alendal et al.).
   4. Large-scale development of the mid-Norwegian margin during the last 3 million years (L. Rise et al.).
   5. The Pleistocene to recent geological development of the Ormen Lange area (K. Berg, A. Solheim, P. Bryn).
   6. Late Cenozoic glacial history and evolution of the Storegga Slide area and adjacent slide flank regions, Norwegian continental margin (B.O. Hjelstuen et al.).
   7. The glacial North Sea Fan, southern Norwegian Margin: architecture and evolution from the upper continental slope to the deep-sea basin (A. Nygård et al.).
   8. Contourites and their relevance for mass wasting along the Mid-Norwegian Margin (P. Bryn et al.).
   9. The Storegga Slide complex: repetitive large scale sliding with similar cause and development (A. Solheim et al.).
   10. Mineralogical and microstructural development of the sediments on the Mid-Norwegian margin (C.F. Forsberg, J. Locat).
   11. The dating and morphometry of the Storegga Slide (H. Haflidason et al.).
   12. Postglacial seismicity offshore mid-Norway with emphasis on spatio-temporal-magnitudal variations (H. Bungum, C. Lindholm, J.I. Faleide).
   13. Probabilistic and deterministic seismic hazard results and influence of the sedimentary Møre Basin, NE Atlantic (C. Lindholm et al.).
   14. Stress transfer in the Storegga area, offshore mid-Norway (K. Atakan, A. Ojeda).
   15. The last phase of the Storegga Slide: simulation of retrogressive slide dynamics and comparison with slide-scar morphology (P. Gauer et al.).
   16. On the dynamics of subaqueous clay rich gravity mass flows - the giant Storegga slide, Norway (F.V. De Blasio et al.).
   17. Scaling behaviour of clay-rich submarine debris flows (D. Issler et al.).
   18. The Storegga Slide tsunami - comparing field observations with numerical simulations (S. Bondevik et al.).
   19. Fundamental mechanisms for tsunami generation by submarine mass flows in idealised geometries (K.B. Haugen, F. Løvholt, C.B. Harbitz).
   20. A parametric study of tsunamis generated by submarine slides in the Ormen Lange/Storegga area off western Norway (F. Løvholt, C.B. Harbitz, K.B. Haugen).
   21. Ocean warming and gas hydrate stability on the mid-Norwegian margin at the Storegga Slide (J. Mienert et al.).
   22. The Storegga slide: evaluation of triggering sources and slide mechanics (T.J. Kvalstad et al.).
   23. Formation of large, crater-like evacuation structures in ooze sediments in the Norwegian Sea. Possible implications for the development of the Storegga Slide (F. Riis et al.).
   24. In situ pore pressures: What is their significance and how can they be reliably measured? (J.M. Strout, T.I. Tjelta).
   25. Ocean bottom seismometer investigations in the Ormen Lange area offshore mid-Norway provide evidence for shallow gas layers in subsurface sediments (J. Mienert et al.).
   26. Soil conditions and slope stability in the Ormen Lange area (T.J. Kvalstad et al.).
   27. Quantification of risks associated with seabed instability at Ormen Lange (F. Nadim, T.J. Kvalstad, T. Guttormsen).