TITLE:
Well-Based Quantitative Reservoir Characterization of Eocene Sokor-1 Formation, Termit Basin, Niger
AUTHORS:
Hassane Amadou, Chukwuemeka Ngozi Ehirim, Tamunonengiyeofori Dagogo
KEYWORDS:
Petrophysics, LCLR Reservoirs, Elastic Properties, Crossplots, Termit Sub-Basin
JOURNAL NAME:
International Journal of Geosciences,
Vol.12 No.2,
February
26,
2021
ABSTRACT: The Eocene Sokor1 Formation is proven oil reservoir
rocks in the Termit sub-basin. These sandstone intervals are deeply buried,
highly heterogeneous in character and characterized by Low Contrast Low
Resistivity (LCLR) log responses. Petrophysical and quantitative well-based
rock physics interpretations were integrated for property estimations, fluid
and lithology typing in reservoir characterization. Six (6) reservoir sandstone
intervals were identified, delineated and correlated across five (5) wells. The
estimated petrophysical properties showed that the Eocene Sokor1 sandstones
have averagely good reservoir properties with sand_5 interval exhibiting
exceptional reservoir properties. Vp/Vs vs. AI and μρ vs. λρ elastic cross-plots color coded with
reservoir properties (Vsh and Φ), show distinct and well
separated data clusters signifying hydrocarbon bearing sandstones, brine
sandstones and shales/mudstones in the 3D crossplot planes with varying seismic
elastic property values in each well thereby, enhancing reservoir
characterization and providing information’s about the burial history,
reservoir quality and property distribution in the sub-basin. The analysis suggests
that, although the reservoir interval has averagely good petrophysical
properties in all wells, the seismic elastic crossplots show that these
properties are much better distributed in wells 2 and 3 than in wells 4, 5 and
9. Therefore, sand_5 reservoir interval in wells 2 and 3 is likely
to be more hydrocarbon bearing and productive than wells 4, 5 and 9 in the
sub-basin.