3D Geological Modelling of Algerian Glacial Ordovician Reservoirs
Dauphin, Léna1, Guy
Desaubliaux2, Angélique Martin1,
Laurent Escaré1, Eric Portier1 (1) Gaz
de France, Saint Denis La Plaine, France (2) Institut Français du Pétrole, 92852 Rueil Malmaison Cedex, France
One of the key challenges in the
exploration and exploitation of hydrocarbon reservoirs lies in a detailed and
realistic understanding of the shape, size and spatial distribution of the
reservoir and non-reservoir subsurface features.
A 3D geological model of the silicoclastic Cambro-Ordovician
reservoirs of an Algerian gas field was built for reservoir simulation and
reserves estimation purposes. This model is based on the integration of all
available seismic and well data, as well as outcrop analogue models.
To build such a realistic 3D model,
geological knowledge of the sedimentary architecture is fundamental. The
Ordovician reservoirs are made of glacial to periglacial
deposits organised in several erosive units. The sedimentological study was performed in collaboration with
IFP (Institut Français du Pétrole) and is presented in
an associated poster (proposed for Theme V / P-37 Session).
Data inputs for the geocellular
model consist in standard structural and reservoir unit thickness maps, but
also more specific sedimentary facies distributions,
well correlations and geometrical organisation
typical of glacial deposits. Simulation methods were also used to produce a
deterministic base case that fits both the subsurface data and the sedimentological model.
Petrophysical ranges associated to
each unit or facies, and deduced from core and log
data, appear to be clearly related to the deposit features themselves. This
point confirms that the sedimentological model
remains a key driver to the understanding of these reservoirs, and also brings
valuable QC to the "hard" and "soft" data integration.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California