i didn't see yet something called pliocene carbonate reservoir in egypt, i know just there are some carbonate streaks of carbonate in the pliocene section of nile delta but no one can consider reservoir, also at offshore north sinai, the carbonate content is very high in pliocene clastic sediments, but also not reservoir, we drilled a well few months ago, targeting pliocene carbonate from seismic interpretation, but it was water bearing clean loose sand.
i hope to help you , can you give us more information, may be i can help ?