  In recent years, water needs increased, driven by climate change and world
population growth. In this context, we study groundwater flow in the vadose
zone of Beauce aquifer (O-ZNS site, France). This lacustrine limestone vadose
zone is characterized by multi-scale heterogeneities. They are defined by
strongly various pore structures. This leads to uncertainties for reservoir
properties prediction using geophysical methods which impacts reservoir models
for flow simulations.In this study, we combined microstructure description and
petrophysical analysis in order to model and predict reservoir properties based
on different limestones facies and to infer the influence of
weathering/fracturing on both acoustics and electrical properties.A total of 16
samples from these facies were cored and characterized by their porosity,
permeability, acoustic velocities, complex electrical properties and
microstructure analysis.Based on our multi-method approach, we demonstrated the
influence of rock structure on reservoir properties prediction and modelling.
Petrophysical and microstructure characterization have highlighted two main
facies (microporous and homogenous facies and macroporous and heterogenous
facies) which can be used to improve reservoir and flow models. However,
further development is needed in order to quantify macropores and their link
with weathering and to assess permeability models using electrical properties.
