Print this pageThe Main Reservoir Features of the Oil-bearing Carbonate Deposits in External Albanides
ZAKA, M., and L. MAHMUTAJ
Carbonate oil and gas fields in External Albanides are mainly encountered in he Kurveleshi Belt of the Ionian zone (as in Greece) which in the west are ordered with Sazani tectonic zone (Paxos in Greece), eastward with Kruja tectonic zone (or Gavrova in Greece) and north-westward with southern Adriatic Basin.
Lithologically, the reservoir consists of an intercalation of clastic organeous limestones with micritic ones. The thickness is about 600-700 m and includes he deposits from Upper Cretaceous to Eocene.
Based on petrophysical studies (open porosity by kerosene saturation, absolute porosity, capillary pressure analysis, petrographic examinations, etc.) performed both on surface samples and wells cores, important conclusions have been drawn both for fractures and intragranular porosity.
The fissures are developed according to four oriented systems with an average effective fissures density about 60/m for clastic limestones and 20-30/m for micritic ones. The effective porosity values range in 5-10% for clastic rocks and 0.5-2 percent for micrits, while the permeability ranges 20-600 millidarcy (md). The total thickness is divided into four lithological packages with colectoral properties which are analysed in the article and some practical uses for oilfield exploitation are also given.