Sedimentary facies in the fluvial-dominated Åre formation as seen in the Åre 1 member in the heidrun field

Detrital Rutile Geochemistry and Thermometry as Guides to Provenance of Jurassic-Paleocene Sandstones of the Norwegian Sea

“…Sandstones are present in the Lower-Middle Jurassic Åre, Tilje, Ror, Ile, Not, and Garn formations (Dalland et al 1988) but become scarce in the Late Jurassic, which is dominated by deposition of organic-rich mudrocks. The Åre Formation (latest Triassic to Early Pliensbachian) was deposited in a fluvial to deltaic setting (Dalland et al 1988;Kjaerefjord 1999;Svela 2001). The overlying Tilje Formation (Sinemurian to Pliensbachian) is composed of interbedded sandstones, mudstones, and siltstones, deposited in a deltaic to shallow marine setting (Dalland et al 1988;Martinius et al 2001;Svela 2001).…”

“…The Åre Formation (latest Triassic to Early Pliensbachian) was deposited in a fluvial to deltaic setting (Dalland et al 1988;Kjaerefjord 1999;Svela 2001). The overlying Tilje Formation (Sinemurian to Pliensbachian) is composed of interbedded sandstones, mudstones, and siltstones, deposited in a deltaic to shallow marine setting (Dalland et al 1988;Martinius et al 2001;Svela 2001). The Ror Formation (Toarcian) consists of marine shelf deposits comprising sandy mudstones with coarsening-upwards sandier units (Dalland et al 1988).…”

Facies controls on the distribution of diagenesis and compaction in fluvial-deltaic deposits

“…Right: Top Are reservoir structure, fluid distribution (after Svela (2001)) and the location of studied wells. zone) and wells 6507/8-D-4 BHT3 (oil zone), 6507/7-A-27 (water and oil zone), 6507/7-A-46 (water and oil zone), covering all the identified facies associations.…”

“…This is interpreted as recording a change from fluvial dominated deposits in the lower part to deposition under increasing marine influence on a lower delta plain environment in the upper part, hence a transgression (e.g. Leary et al, 2007;Svela, 2001). A regional channel sand body complex (incised valley?)…”

“…The reservoirs in the Heidrun Field are located at relatively shallow burial depths (2.5 km or less) and where quartz cementation has less or no impact on porosity. The target in this study is the Åre Formation of Rhaetian -Hettangian age comprising heterogeneous sediments deposited in a fluvial plain to lower delta plain environment with swamps and fluvial channel deposits passing upwards into marginal marine facies (Dalland et al, 1988;Kjaerefjord, 1999;Koch and Heum, 1995;Olsen et al, 1999;Svela, 2001;Whitley, 1992). Due to the heterogeneous nature of the sediments there are large difficulties in correlating the sandstone beds/reservoir flow units.…”