Is There a Viable Petroleum System in the Carson and Salar Basins, Offshore Newfoundland?

Abstract

The Carson Basin on the eastern Grand Banks of Newfoundland has been penetrated by four wells ‐ Bonnition H‐32, Osprey H‐84, Skua E‐41 and St. George J‐55 ‐ which were drilled along its western margin. The adjacent deeper‐water Salar Basin to the east remains undrilled with the exception of ODP holes 1276A and 1277. The Carson Basin wells contain a thick Mesozoic and Cenozoic sedimentary section which includes reservoirs and seals; but source rocks, such as those present in the adjacent Jeanne d'Arc Basin, have not been found. To assess the petroleum system, well samples were collected to provide Rock Eval and vitrinite reflectance data, and analysed biostratigraphically to obtain ages and depositional environments. These analyses indicate that a Late Jurassic source rock, similar to the Egret Member (of the Rankin Formation) of the Jeanne d'Arc Basin, may be present in the deeper‐water, distal parts of the Carson and Salar Basins; this is based on a regional palaeotectonic reconstruction, together with gravity and magnetic data, including sea‐floor spreading magnetic anomalies. We interpret the absence of the Egret Member in the four wells to reflect the wells' locations rather than the Member's absence from the two basins. An integrated 4D model of the Carson Basin was built from biostratigraphy and seismic surfaces, to which an Egret‐like source rock was added. The modelling showed that significant volumes of hydrocarbons could have been generated, mostly during the main Late Cretaceous drifting event in the area. Hence, significant volumes of hydrocarbons could be present in the Carson and Salar Basins, mainly in stratigraphic traps in Early Cretaceous clastic reservoirs.

The syn‐rift tectono‐stratigraphic record of rifted margins (Part II): A new model to break through the proximal/distal interpretation frontier

“…Sediment deposits may include shallow‐marine carbonates and/or shallow‐marine‐ or terrestrial sandstones (e.g. Newfoundland margin; Wielens et al., 2006, Norwegian margin; Faleide et al., 2010, Porcupine Basin; Whiting et al., 2020). Syn‐necking sandstones are possibly derived from immediately adjacent exhumed basement domes/core complexes (e.g.…”

“…Drill holes in the northern part of Carson Basin (Newfoundland margin; Figure 8a) indicate a Tithonian unconformity overlain by sandstone deposits, like that reported in the Jeanne d’Arc Basin (Ian Sharp personal communication). A later Albian unconformity in the northern Carson Basin is interpreted to mark the rift to drift transition in the southern segment (Wielens et al., 2006).…”

“…In addition to drill hole data from the proximal domain and inner part of the necking domain (e.g. Alves et al, 2002, on the Iberian side; Sinclair, 1994 and references therein; Wielens et al, 2006, on the Newfoundland one), deepwater drilling was performed in the Iberian hyperextended domain and in the inner part of the Newfoundland exhumed mantle domain, as part of the Ocean Drilling Program (ODP) Legs 149, 173 and 210. Besides, the viability of the tectono-stratigraphic interpretation by Sutra et al (2013) was supported by its surface-conservative kinematic restoration.…”

“…Drill holes in the northern part of Carson Basin (Newfoundland margin; Figure 8a) indicate a Tithonian (Wielens et al, 2006).…”

Basin modeling meets rift analysis – A numerical modeling study from the Jeanne d'Arc basin, offshore Newfoundland, Canada

“…During the Late Cretaceous, basin-wide subsidence caused deposition of predominantly fine-grained siliciclastics and carbonates (Deptuck et al, 2003;Grant et al, 1986b;Swift et al, 1975;Wielens et al, 2004). As a consequence of high sea-level fluctuations during the Cenozoic thick shales with interbedded sandstones were deposited via incised canyons at the western margin of the basin (CNLOPB, 2004;Deptuck et al, 2003).…”