On the role of reservoir geometry in waterdrive hydrodynamics
M. Ferronato, G. Gambolati, P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
ABSTRACT
The interaction of producing reservoirs with the connected waterdrive plays
an important role both in planning the field production life and predicting
the environmental consequences (e.g. anthropogenic land subsidence) of
hydrocarbon extraction. Currently, the behavior of the system
reservoir + waterdrive can be simulated with the aid of advanced numerical
models, but one of the most difficult tasks is the calibration of the poorly
known aquifer hydrogeological properties. In the present paper, the waterdrive
hydrodynamics is simulated by a finite element flow model with the parameters
calibrated so as to satisfy the material balance equation. Two field cases in
the Northern Adriatic basin, Italy, are discussed, pointing out the role of
reservoir geometry for a reliable simulation of the waterdrive dynamics. It
is shown that quantities which are often neglected, such as the amount of
water withdrawn along with the gas and the pore volume reduction experienced
by the field, may be of paramount importance for the waterdrive calibration
depending on the actual reservoir geometry. The results suggest that an
in-depth knowledge of the reservoir geological configuration is required to
accurately simulate the waterdrive hydrodynamics, and hence predict the
expected amount of gas/oil withdrawn and the related anthropogenic land
subsidence.
