Reservoir Types and Characterization of the Pre-Apulian Zone in Ionian Islands

Marios Patsoules
Hellenic Petroleum S.A, Maroussi, Greece

In the present work the geographical, stratigraphic and tectonic setting of the chalky limestones and chalky deposits of western Greece will be discussed and their sedimentological and petrophysical features will be presented with respect to their geological ‘makeup' as reservoirs. The studies include measurements of porosity and permeability as well as the quantitative characterization of the reservoir rocks using capillary pressure curves and other microscopic observations. It may be noticed that in order to examine and better understand the flow of fluids found to be saturating the porous formations of the western Greek islands, especially Zakynthos, the greatest attention was given to the evaluation of properties previously mentioned, as well as to comparative studies with similar formations of Europe. Of course, the object of the work was to examine rock characteristics in some non conventional parts of the reservoirs (specifically in their fractured zones), thus, only discrete parameters have been taken into consideration. In that respect, some properties, such as permeability and porosity, have been discussed as properties of fractures or even better of the fracture-matrix system. Particular attention has been given to the morphology of curves of the capillary pressure measurements and the resulted petrofacies. Since the formation oil, found to be highly viscous and sometimes mixed with meteoric waters, the hydraulic properties en mass have been also studied for the greater area by employing special geochemical data.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece