Provenance, depositional setting and diagenesis as keys to reservoir quality of the Lower Cretaceous in the SW Barents Sea

This study examines the role of depositional environment for final reservoir quality in four Lower Cretaceous sandstone reservoirs southwestern Barents Sea by linking facies to distribution primary textures, composition, and diagenetic alteration. Facies analysis reveals slope-to-basin-floor, distal shallow-marine, deltaic environments. The slope-to-basin-floor has highest porosity 3–19% (avg. 13%). It is attributed good sorting, non-pervasive carbonate cementation that inhibited compaction allowed secondary through later dissolution, moderate clay infiltration resulted cutanes on grain rims precipitation chlorite (which quartz growth). For sandstone, fluctuating energy sediment supply provided conditions mechanical varying 2–18% 8%). shallow-marine lowest 1–12% 7%). Based its fine-grained bioturbated character, deposition a low-energy with low seems likely. combination lamina, interstitial matrix bioturbation led reduction. Abundant mica feldspar grains partly result provenance, deep burial also extensive illitization. High mineralogical maturity, much monocrystalline quartz-grain populations, similar felsic chemical rock compositions all associations wells indicate source rocks some variations. mechanically unstable makes nearby Loppa plausible catchment, which supported seismic geometries. demonstrates evolution studied determined mainly despite minor provenance major