Study of the TFT (the Amassak field) Ordovician reservoir by means of geological and petrophysical

Abstract

This dissertation characterizes the Ordovician Amassak (MSK) reservoir in Algeria's Illizi basin. The reservoir consists of Ordovician sands overlaid by Silurian clays, with Unit IV-3 being the most substantial reservoir unit (13 meters thick). Geologically, the reservoir formed in a glacial to preglacial environment. The study identified two main sandstone groups: structured (traction current deposits) and unstructured (gravitational/turbiditic deposits). Structurally, the area is characterized by a monocline and fractures. The largest fault reaches 300 km. Petrophysical analysis indicates good quality reservoir properties. The most significant zones for hydrocarbon production are in the northeastern region, particularly in Unit IV-3 and, to a lesser extent, in underlying sandstones. Units IV-2 and III-3 together form the terminal Ordovician complex, deposited in a glacial to preglacial environment. Unit III-3 also contains a reservoir within its sandstones.