Multi-GPU based 3D numerical modeling of fluid migration and clay dehydration influence on Lusi hydrothermal activity (Java, Indonesia)

The Lusi mud eruption in East Java has been active since May 2006. Magma emplacement at depth, clay dehydration, and mud liquefaction during seismic wave propagation have been invoked as mechanisms fueling this eruption. However, the respective roles of these processes are still poorly constrained. In this focused study, we numerically investigate the influence of clay dehydration, mass and heat transport on fluid outflow at the Lusi site using a fully coupled 3D model for this active system. Using a multi-GPU parallel processing algorithm, we propose an estimate of the 3D time evolution of pressure, temperature, porosity, permeability and water liberation in a large-scale (9 km - 14 km - 5.5 km) deep hydrothermal system at high-resolution. Simulations indicate that high-pressure fluids generated by dehydration reactions are sufficient to induce hydro-fractures that would significantly influence the porosity and permeability structures. Dehydration is an essential component for understanding the Lusi system, because the fluids generated contribute to the outflow and may have a considerable impact for the maintenance of the infrastructure required to keep the Lusi site safe. High-Performance Computing (HPC) offers high-resolution simulations for studying time evolution of such natural systems, and potentially for geothermal resource development for the surrounding population.