Robust numerical implementation of a 3D rate-dependent
model for reservoir geomechanical simulations
G. Isotton, N. Spiezia
M3E Srl, Padova, Italy
P. Teatini M. Ferronato, C. Janna
Dept. of Civile, Environmental and Architectural Engineering,
University of Padova, Padova, Italy
S. Mantica, G. Volonte'
Eni S.p.A., Milan, Italy
ABSTRACT
A 3D elasto-plastic rate-dependent model for rock mechanics is formulated
and implemented into a Finite Element (FE) numerical code. The model is
based on the approach proposed by Vermeer and Neher (A soft soil model that
accounts for creep. In: Proceedings of the International Symposium “Beyond 2000
in Computational Geotechnics,” pages 249-261, 1999). An original strain-driven
algorithm with an Inexact Newton iterative scheme is used to compute the state
variables for a given strain increment. The model is validated against laboratory
measurements, checked on a simplified test case, and used to simulate land
subsidence due to groundwater and hydrocarbon production. The numerical results
prove computationally effective and robust, thus allowing for the use of the
model on real complex geological settings.
