| Summary: | 39 thin sections and petrophysical log data from the Skalle well in the Hammerfest Basin, in the southwestern part of the Barents Sea, have been studied to interpret lithology, and diagenesis and their effect on the reservoir quality, and to compare reservoir properties of the different reservoir units. Petrophysical log data have been calibrated for reservoir description in cases where core material is not available. The studied formations are comprised by the Stø, Fuglen, Hekkingen, Knurr, Kolje and the Lower Kolmule Formations. The Knurr and Kolje Formations have been identified and interpreted only by wire line logs, as core material was not available for those intervals.The Lower Kolmule Formation of sandstones of lithic greywacke composition, and the Stø Formation with sandstones of subarkosic arenite composition are considered as possible reservoir rocks. All the formations are water filled which is reflected by the low resistivity logs responses. The mature sandstones of the Stø Formation show high reservoir quality (high porosity and permeability) compared to the Lower Kolmule Formation. The Hekkingen Formation is a potential source rock for the Lower Kolmule Formation, as well as a seal (cap rock) for the Stø Formation. Cementation, dissolution, compaction, clay mineral authigenesis and stylolitization are the most significant diagenetic processes affecting the reservoir quality. Some other type of processes such as glauconitization and bioturbation are also common in the studied well.
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