Sedimentology of the upper Åre - lower Tilje formations with emphasis on lateral variations based on selected wells at the Halten Terrace, Mid-Norway.

Abstract

Seven core descriptions covering the Top Åre Formation/Base Tilje Formationtransition were made from the following Fields and wells: the Smørbukk Field(6506/12-K-3H, 6506/11-5 S and 6506/11-4 ST2), the Lavrans Field (6406/2-1and 6406/2-4 SR) and the Njord Field (6407/7-1 S and 6407/7-4).As a result of the core descriptions: Seven facies associations (FA Å1-Å7) from the observed upper Åre Formationwere interpreted. Five facies associations (FA T1-T5) from the observed lower Tilje Formationwere interpreted. Three major erosive surfaces were interpreted and correlated in the vicinityof or at the Top Åre Formation/Base Tilje Formation transition surface.Eleven wells were used for wireline log correlation of the Top Åre Formation/BaseTilje Formation transition surface, six of these wells were the same ones used forthe core description, with the exception of the Smørbukk 6506/11-4 ST2 well,since it did not have wireline logs that covered the area of interest. The restof the wells were picked from field and discovery wells that penetrated both theTilje and °Are Formation, between the wells used in the core description. LinnormDiscovery (6406/9-2 and 6406/9-1), Spinell Discovery (6407/4-1), NoatunDiscovery (6407/7-8) and the Hyme Field (6407/8-5 S).As a combined result of the core description and the wireline log: The erosive surfaces seen in the core description were recognised in wirelinelogs. Facies associations from the core descriptions were linked with correspondingwireline log response. Clear differences in the interpreted upper Åre Formation are seen from theSmørbukk and Lavarans Field compared to the Njord Field. The Top Åre Formation/Base Tilje Formation transition surface were correlatedbetween the chosen wells.