Paleogene prospectivity of the NE Atlantic volcanic margins constrained by new 3D seismic data on the Møre Margin

Abstract

Paleocene and Eocene sandstone reservoirs have been the target of the majority of exploration boreholes in the Faroe-Shetland Basin, with over 20 notable discoveries including intra-basalt sandstone traps in the Rosebank field. Further north, the major Paleogene Ormen Lange gas field and the Tulipan discovery are located on the Møre Margin, whereas several gas discoveries have been made in Paleocene and upper Cretaceous sandstones in the Vøring Basin, including the Aasta Hansteen field which will likely come on-line in 2018. Only a few exploration boreholes have been drilled in the frontier outer Møre Basin. In 2017, TGS completed the acquisition of two huge 3D seismic surveys (30,000 km2 combined), covering large areas of the Møre and southernmost Vøring basins. These surveys are now revealing unprecedented insights into the geological structure and prospectivity of these frontier regions whilst opening new exploration opportunities. We have completed a comprehensive seismic interpretation of the Paleogene and Cretaceous sequences in the outer Møre Basin, with focus on the structural and sedimentological framework and associated igneous complexes. The interpretation has been tied to key wells in the Faroe-Shetland Basin and wells on the Norwegian margin. Turbidite sandstones are present in large parts of the outer Møre Basin, forming major dome-shaped structural and stratigraphic traps. The sandstones may be sourced from the conjugate NE Greenland in the west or the Norwegian-Shetland mainland to the east. Source rocks are likely Cretaceous shales. Seismically imaged gas leakage pipes, and shallow gas hydrates and free gas below the gas hydrate stability zone, indicate the presence of an active petroleum system. Large-scale volcanism was associated with the continental breakup in the Paleogene. Seismic imaging within volcanic basins has historically inhibited exploration due to scattering and energy loss associated with volcanic facies - the so-called sub-basalt imaging problem. However, with the acquisition of high quality 3D seismic surveys and the application of igneous seismic geomorphology, new insights into the evolution of volcanic rifted margins and their associated sub-basalt petroleum systems has been enabled. The extrusive lavas and hyaloclastites along with intrusive sill complexes have influenced the petroleum system in both positive (e.g. trap formation, enhanced maturation) and negative (e.g. compartmentalization, volcaniclastic sediment input) ways. Improved imaging of the sub- and intra-basalt sedimentary sequences reveal fluvial drainage systems with implications for the input of reservoir sands into the mud dominated deep basins, and the potential for lower Cretaceous or Jurassic prospects below the marginal highs. In conclusion, the regionally extensive outer Møre Basin offers many new exploration opportunities which are currently underexplored, including Paleogene sandstone reservoirs, but also Jurassic, Cretaceous, and even Neogene plays.

AAPG Datapages/Search and Discovery Article #90325 © 2018 AAPG Europe Regional Conference, Global Analogues of the Atlantic Margin, Lisbon, Portugal, May 2-3, 2018