Premium
Numerical computations of rock dissolution and geomechanical effects for CO 2 geological storage
Author(s) -
Wojtacki K.,
Lewandowska J.,
Gouze Ph.,
Lipkowski A.
Publication year - 2014
Publication title -
international journal for numerical and analytical methods in geomechanics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.419
H-Index - 91
eISSN - 1096-9853
pISSN - 0363-9061
DOI - 10.1002/nag.2316
Subject(s) - homogenization (climate) , dissolution , geology , orthotropic material , tortuosity , permeability (electromagnetism) , modulus , geotechnical engineering , computation , rock mass classification , settlement (finance) , mechanics , materials science , porosity , thermodynamics , mathematics , composite material , physics , computer science , finite element method , chemistry , algorithm , biodiversity , membrane , ecology , world wide web , biology , biochemistry , payment
Summary The paper is motivated by the long‐term safety analysis of the CO 2 geological storage. We present a methodology for the assessment of the geomechanical impact of progressive rock dissolution. The method is based on the use of X‐ray tomography and the numerical dissolution technique. The influence of evolution of the microstructure on the macroscopic properties of the rock is analysed by using periodic homogenization method. The numerical computations show progressive degradation of all components of the stiffness (orthotropic) tensor. Moreover, the evolution of associated mass transfer properties (as tortuosity and conductivity tensors), by using the periodic homogenization method, is also calculated. The correlation between the mechanical parameters and the transfer properties during the dissolution process is presented. The results show that the highest increase of the hydraulic conductivity (in direction Y ) is not associated with the highest decrease of Young modulus in this direction. Moreover, the highest decrease of Young modulus (in the direction X ) is not associated with percolation in this direction. Finally, an incremental law to calculate settlement, in case of a rock with evolving microstructure, is proposed. The solution of the macroscopic settlement problem under constant stress and drained conditions showed that the geomechanical effects of the rock dissolution are rather limited. Copyright © 2014 John Wiley & Sons, Ltd.