Details zur Publikation

Kategorie Textpublikation
Referenztyp Tagungsbeiträge
URL http://www.comgeo.org/
Titel (primär) Simulation of dilatancy-controlled gas migration process in saturated argillaceous rock
Titel (sekundär) Computational Geomechanics, ComGeo II - Proceedings of the 2nd International Symposium on Computational Geomechanics, Cavtat-Dubrovnik, Croatia, 27-29 April, 2011
Autor Xu, W.J.; Shao, H.; Hesser, J.; Wang, W. ORCID logo ; Kolditz, O. ORCID logo ; Popp, T.
Erscheinungsjahr 2011
Department ENVINF
Seite von 693
Seite bis 703
Sprache englisch
Abstract

A coupled hydro-mechanical model has been developed to simulate the gas injection tests with increasing gas pressure in saturated argillaceous rock. In the model, the gas migration in porous medium is assumed to be controlled by the gas pressure, the hydro-mechanical states (saturation, stress), and the material properties (permeability, porosity, deformation behaviour). Based on the model, laboratory gas injection tests on a rock specimen of Opalinus Clay have been simulated with the FEM program OpenGeoSys (OGS). The rock specimen is modelled as a continuum anisotropic porous medium. The effective stress is defined by using the saturation as weighting functions for the gas and water pressures. The relationship between capillary pressure and water saturation is described by the van Genuchten function based on laboratory data and the relative permeabilities to gas and water by the approach of Mualem. A modified Drucker-Prager elasto-plastic model, which contains a tensile yield function with associated flow rule, is applied. The simulated gas flow rate evolutions under different gas injection pressures agree very well with the experimental measurement data. Low gas flow rates can be simulated by using a coupled multiphase flow and an elastic model for the rock specimen if the gas injection pressure is higher than the gas entry pressure. If the gas injection pressure is higher than minimal principle stress, a plastic zone with micro fissures may be generated which leads to an increase in permeability of several orders of magnitude.

dauerhafte UFZ-Verlinkung https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=13712
Xu, W.J., Shao, H., Hesser, J., Wang, W., Kolditz, O., Popp, T. (2011):
Simulation of dilatancy-controlled gas migration process in saturated argillaceous rock
Computational Geomechanics, ComGeo II - Proceedings of the 2nd International Symposium on Computational Geomechanics, Cavtat-Dubrovnik, Croatia, 27-29 April, 2011
693 - 703