The Onset of Convection in Faulted Aquifers

Abstract

In any geological formation, faults play an important role as they can range from impermeable seals to fluid pathways. At geological time scales, faults can exhibit steady creep and basins have been known to deform quite considerably. The study of fault mechanics has been widely studied and has been recently shown to play a role in affecting the behaviour of fluid dynamics, namely the geometry of hydrothermal convection cells. Whilst the onset of hydrothermal convection has been extensively studied for more than a decade, little is known about the effects of shear heating of faults on hydrothermal convection. With the need to solve for tightly coupled thermo-hydro-mechanics, we investigate these effects using a new open-source numerical multiphysics simulator, REDBACK. REDBACK is specifically designed to study material instabilities in a tightly coupled manner. Using a linear stability analysis and the implementation of a pseudo-arclength continuation method, it provides the ability to compute the values of critical parameters that predict the onset of convection. The results of this study will present the use of REDBACK to observe the effect of shear heating on the onset of convection.