WP4

Setup of reference model: Modelling thermal stresses of a generic hydrothermal doublet
For typical geothermal reservoir dimensions a generic 3D thermoporoelastic model will be used to deduce the spatio-temporal distribution of  poroelastic and thermoelastic stress changes for testing phase (single well injection, and doublet circulation for a limited time) and for the operational phase (tens of years). 

Subpackages
 4.1 Doublet model for homogeneous and isotropic reservoir properties 
4.2 Inclusion of material anisotropy
4.3 Inclusion of a fault 

Current activities
Manuscript for analytical and numerical model of pressure changes in anisotropic medium for a one-well injection has been submitted. Spatio-temporal evolution of THM stress and corresponding Coulomb failure stress changes ([Formel]CFS) in the homogeneous model is completed. Extension to doublet model within the medium of anisotropic permeability and layered lithology is ongoing. 

Temperature distribution after 10 years of injection in an anisotropic medium with permeability along the y-axis ten times greater than in x- and z- axes. The inset compares the temperature distribution along high (y) and low (x) permeability direction with the isotropic case.