sambuca (lambourka) tech detail, page-10

Trap Integrity: Sambuca is unique in that the vertical throw across the main bounding fault is significantly larger than the surrounding oil fields. It therefore does not have a sand to sand juxtaposition problem which causes partial leakage and underfill compared to structural size. Tops seals for all reservoir intervals are proven in the nearby area and are of very high confidence. The seal and trap integrity risk across the Sambuca main bounding fault is perceived to be low, especially for the main Birsa oil reservoir.

Nearby well data demonstrates (i.e. Dougga-1) that the hanging wall Pliocene section juxtaposed against the footwall Birsa reservoir sands consists of deep marine claystones and therefore represents an excellent seal. In addition to the Pliocene claystines Miocene shales of the Tazerka group above the Birsa sandstones could also be part of the hangingwall fault seal.

Such a situation applies to the Tazerka and Zibbibo oil fields. The Miocene shales have sufficient capacity to hold back gas accumulations such as the significant CO2 gas cap in the nearby Zibbibo oil field.