The impact of salt tectonics on the Mesozoic sedimentation and petroleum systems of the Norwegian Barents Sea

• Published in: AAPG Bulletin
• Main Author: Rojo Moraleda, Luis Alberto
• Other Authors: Cardozo, Nestor, Escalona, Alejandro, Koyi, Hemin
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Stavanger: Universitetet i Stavanger 2020
• Subjects: petroleumsgeologi; Barentshavet; VDP::Teknologi: 500::Berg‑ og petroleumsfag: 510; Barents Sea; Tromsø; Barentshav*; Nordkapp; Nordkapp Basin
• Online Access: https://hdl.handle.net/11250/2678406

In the Norwegian Barents Sea, Mesozoic and Cenozoic mobilization of Pennsylvanian-lower Permian layered evaporite sequences (LES) resulted in areas with salt tectonics (e.g. Nordkapp, Tromsø and Tiddlybanken basins), which affected the development of Upper Paleozoic and Mesozoic petroleum systems. Over the last three decades, seismic imaging in these salt-bearing basins has been a challenge due to the presence of closely spaced salt diapirs and steep minibasin strata. Consequently, there is limited information and integrated studies, and the dynamics of salt mobilization and its effect on the petroleum systems remain poorly understood. This research applies a wide range of methods to subsurface data in the Nordkapp and Tiddlybanken basins to: (1) provide a tectonostratigraphic evolution of the basins; (2) understand the influence of salt movement on Mesozoic prograding overburdens; and (3) address the thermal effect of salt in the petroleum systems of the Barents Sea. The results are presented in five papers. Paper I improves the understanding of salt tectonics in the Nordkapp Basin based on interpretation of subsurface data and structural restorations. Our results indicate that a combination of Early Triassic basement-involved extension and sediment progradation resulted in diachronous salt mobilization and sediment infill along the basin. Important processes such as diapirism, minibasins formation, welding, and salt depletion occurred earlier in the central and eastern sub-basins than in the western sub-basin. The paper also highlights the importance of salt rheology and subsalt relief for the nucleation and distribution of salt structures and minibasins. Paper II aims to understand the controls on suprasalt structural style in confined salt-bearing basins based on analogue experiments. The paper compares the structural styles resulting from basement involved extension and progradational loading. Moreover, it highlights the impact of subsalt relief on suprasalt deformation by comparing different subsalt basin ...