Oil seepage onshore West Greenland: evidence of multiple source rocks and oil mixing

Abstract

Widespread oil seepage and staining are observed in lavas and hyaloclastites in the lower part of the volcanic succession on northwestern Disko and western Nuussuaq, central West Greenland. Chemical analyses suggest the existence of several petroleum systems in the underlying Cretaceous and Paleocene fluvio-deltaic to marine sediments. Seepage and staining commonly occur within vesicular lava flow tops, and are often associated with mineral veins (mostly carbonates) in major fracture systems.

Thermal maturity, hydrocarbon potential and kerogen type of some Triassic–Lower Cretaceous sediments from the SW Barents Sea and Svalbard

“…Thus, especially in the Svalbard samples, climatic aspects (Karlsen et al, 2004) or lateral connectivity or openness of the reservoir (Ahsan et al, 1997) seems to be important elements to consider to understand biodegradation. This is consistent with the generally nonbiodegraded outcrop samples from West Greenland described by Bojesen-Koefoed et al (1999), who also reported more degradation in samples where hydrocarbons were flushed by water.…”

“…Igneous and metamorphic rocks can also be reservoir rocks if they have fractures. For example, occurrences of oil stains and impregnations in volcanic rocks are known from Greenland (Bojesen-Koefoed et al, 1999;Christiansen et al, 1998;Pedersen, 1986;Pedersen et al, 2007) and Embla Field, North Sea (Paper 4).…”

Tectonic variation and structural evolution of the West Greenland continental margin

“…However, slight gas show were recorded in the lowermost part of the sedimentary sequence in Kangâmiut-1 well (Rolle, 1985). In the 1980s and early 1990s, two breakthroughs in prospectivity along the West Greenland margin were that (a) an improved understanding whereby the sedimentary basins that could contain oil and gas were much larger than earlier thought and (b) the discovery of extensive oil seeps onshore in the Nuussuaq Basin (Chalmers & Laursen 1995, Chalmers et al 1993Bojesen-Koefoed et al 1999). At the end of the century, Qulleq-1 well was drilled in 2000 (Pegrum, 2001) by the Statoil group as part of their commitments in the eastern sub-area of the Fylla licence.…”

Mapping and facies analysis of Paleocene–Mid-Eocene seismic sequences, offshore southern West Greenland

“…See text for discussion. Basin, has been attributed to a source rock 'not likely to pre-date the latest part of the Late Cretaceous' (Bojesen-Koefoed, Christiansen, Nytoft, & Pedersen, 1999). This source rock appears to have been encountered in the GRO#3 well where there is "… a remarkable similarity in geochemistry between the mudstones from the interval from 320 to 510 m … and the Marraat oil type" .…”