Print this pagePredictive Petroleum System Model of Prospective
Yahaya Mohammed, Geology Department, University of
Anambra basin; a Cretaceous/Tertiary basin is the structural link
between the Cretaceous Benue trough and the Tertiary Niger Delta basin.
Spatially, it is the Sedimentary wedge bordered by the Abakaliki anticlinorium
to the East, the basement rock and the
Petroleum-Hydrocarbon system
encompass source rocks, the process of generation and migration of the
hydrocarbons and the geologic elements of traps, seals, and reservoirs that are
essential for a hydrocarbon accumulation to exist,
The Anambra
basin contains about 6000m thickness of Shales and Sandstones. Potential source
rocks are the shales of Asata/Nkporo formation and Mamu formation that have
total organic contents ranging from 0.4% to 4.8%. Kerogen is mostly of type
Ц and Ш. Sandstone stringers in the Nkporo formation and Sandstone
interbed of the coal measures have proven to be adequate hydrocarbon reservoir
with porosity value from 15% to 35% and adequate permeability.
The early Cenomanian
and later Santonian deformation lead to the formation of simple folds and
faults that play a part in the hydrocarbon trapping mechanism of the basin. The
stacking of sediments in a Southerly direction, have also promoted the
formation of growth faults. The rejuvenation of movements on the basement
faults also lead to formation of possible traps. The alternation of marine and
continental deposits is also highly conducive to the formation of stratigraphic
traps.
The Imo shale deposited during the
Tertiary marine transgression has good sealing characteristics as it has not
suffered any regional deformational event.