Quaternary and Neogene Reservoirs of The Norwegian Continental Shelf: Evidence from New 3D Seismic Data

Summary Quaternary and Neogene sediments are commonly known for their sealing properties and potential drilling hazards. However, examples such as the Peon and Aviat discoveries in the North Sea show that shallow reservoirs can be prospective. In this study, we use 2D and 3D seismic data combined with well information to document new unconventional play models from the shallow subsurface of the Norwegian Continental Shelf. These plays include (i) glacial sands in an ice-marginal outwash fan, sealed by stiff subglacial tills formed by repeated glaciations (the Peon discovery in the Northern North Sea), (ii) fine-grained glacimarine sands of contouritic origin sealed by gas hydrates, (iii) remobilized oozes above large evacuation craters and sealed by megaslides and glacial muds, and (iv) Neogene sand injectites. The reservoirs are characterized by phase-reserved reflections with anomalously high amplitudes in the seismic data and density and velocity decreases in the well data. Extensive new 3D seismic data are crucial to correctly interpret glacial processes and distinguish shallow reservoirs from shallow seals. The data indicate a variety of play models with the potential to have gas in economic quantities and enable the identification of the optimal drilling targets at stratigraphic levels often considered to be not prospective.