Abstract: Evaluation of hydrocarbon potential in Bechar Oued Namous basin
BRAIK F, S. MERABET, R. HACHED
The Bechar-Oued Namous is located on the northern margin of the Saharan platform. It is bordered on the north by the Atlas trough Timimoun basin and Azzen high represent its southern limit.
The main reservoirs in this
area are Siegenian and Famennian sandstones which are situated in Meharez-
Oued Namous high. The upper Dkhissa formation of the Siegenian age is made
up of a lowstand systems tract and transgressive systems tract. This formation
has stratigraphy, developed in a deltaic to open marine environment, favoring
the presence and the development of potential sandstone reservoirs within
Meharez- Oued Namous high. In the same way, lowstand and highstand systems
tract identified in the Famennian shaly- sandstone of Marhouma Formation
present good porosities
. These systems tract correspond to two deltaic
phases. The diagenetic phenomena control the petrophysical properties of
these sandstone bodies. Secondary
porosities
related to the different dissolution
phases have been confirmed.
Oil-prone source rocks
in the
late Devonian and lower Silurian sequences have been proven from well and
outcrop sections in and around the Bechar-Oued Namous basin. These are
likely to be mature for hydrocarbons on the highs in the basin and over
mature in the lows.
Gas-prone source rocks
occur
in abundance in the Visean and the Westphalian, and the Hercynian folding
which affected this zone has created a number of structural traps. Early
Carboniferous normal faults have been reactivated as reverse faults during
Hercynian compression. The generation of hydrocarbons was projected to
be synchronous with Hercynian structuring.
AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria