Fig. 5

Porosity model for the Gassum formation. A porosity–depth relationship is suggested using data from selected Danish onshore wells. For location of wells, see Fig. 1. The depth scale shows estimated maximum burial depth, as present-day depths have been corrected for differential uplift. The porosity is interpreted from well-log data (effective porosity). The average net porosity is calculated using cut-offs (min 15 % porosity; max 30 % shale). The porosity deterioration with depth is similar to the general trend in the majority of the onshore wells (Farsø-1, Horsens-1, Hyllebjerg-1, Kvols-1, Oddesund-1, Rødding-1, Skrive-1, Skive-2 and Ørslev-1. A mechanical (or normal) compaction curve published by Gluyas and Cade (1997) is shown for comparison