INVESTIGATIONS INTO THE CAUSES OF HIGH FORMATION PRESSURES IN DEEP DRILLING IN WESTERN GREECE

摘要

This research discusses the occurrences of high formation pressures during the last time there was deep drillingthrough thick evaporitic (mainly anhydrite) sections in northwestern Greece, near loannina. The stratigraphy of the area is composed of Jurassic to Tertiary carbonates underlain by Triassic evaporites. The well structure was a sub-evaporite high, with uncertainty as to the nature of the interval beneath the Triassic evaporites. The hydrocarbon play system depended on the geological model applied. The most likely model comprised carbonate reservoir of Cretaceous-Eocene age, sealed by the Oligo-Miocene Flysch and over-thrusted Triassic evaporites. The reservoir was thought to be sourced from underlying Mesozoic source rock intervals. The alternate, less likely model comprised of Permo-Triassic carbonate-dominated reservoir, sealed by Triassic evaporites and probably sourced from Triassic intervals.