Abstract: Maturation Models and Distribution of Petroleum in Different Sedimentary Basins of Algeria

M. S. Malla, R. Hached, B. Khatir

In petroleum exploration, good knowledge of source rocks and the transformation of organic matter is very important for understanding the origin of discovered pools and evaluation of future prospects. The Silurian and Devonian sediments widespread in Algeria are the main source rocks. Their total organic matter content ranges from 0.5% to more than 20%. Organic matter is type-II and comprise algae, graptolited, chitinozoans, acritarchs and amorphous organic matter. Basin modelling using numerical model program revealed big differences among basins. The Devonian and Silurian are within the oil window for main oil-producing basins (Illizi, Ghadames, Sbaa, and Northern part of Oued-Mya). But the source rocks of Ahnet, Timimoun, Reggane and southern Oued-Mya basins are very mature and can generate only gas as evidenced by the occurrence of oil and gas accumulations. In Saharan Atlas/High Plateaux, geochemical analysis did not show any source rocks, except thin horizons of the Callovian and Toarcian age. Good carbonate source rocks of upper Cretaceous age are present in South-Eastern Constantine region, which are responsible for oil accumulations in this region.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994