Geomechanical characterization of storage reservoirs by assimilation of surface displacements
C. Zoccarato, M. Ferronato, G. Gambolati, C. Janna, P. Teatini
Dept. of Civil, Environmental and Architectural Engineering, University of Padova, Italy
A. Alzraiee, D. Bał
Dept. Civil and Environmental Engineering, Colorado State University, CO
ABSTRACT
Gas injection into the subsurface is becoming increasingly popular worldwide in connection
with Underground Gas Storage (UGS) and CO2 sequestration (CCS) projects. Depleted oil/gas
fields or saline aquifers are strategically used to cope with the growing demand of energy
and the planned reduction of the greenhouse efflux into the atmosphere. Due to the pressure
increase caused by gas injection, porous rock formations expand and land surface rises. The
surface displacements, when accurately measured for example by SAR interferometry, can be
effectively used to evaluate the petrophysical and geomechanical properties of the injected
formation. In this study, an Ensemble Smoother (ES) data assimilation technique is applied
to reduce the uncertainty on the constitutive parameters characterizing the geomechanical
model of a UGS field situated in the Po River basin, north of Italy. The assimilation has
been implemented using vertical and East-West displacements measured by an advanced satellite
technology based on Radarsat scenes collected between 2003 and 2008.
