Effect of permeability on cooling of a magmatic intrusion in a geothermal reservoir

Numerical modeling of the transient cooling of a magmatic intrusion is described in a geothermal reservoir that results from conduction and convection, considering the effects of overlying cap rock and differing horizontal and vertical permeabilities of the reservoir. These results are compared with data from Salton Sea Geothermal Field (SSGF). Multiple layers of convection cells are observed when horizontal permeability is much larger than vertical permeability. The sharp drop-off of surface heat flow experimentally observed at SSGF is consistent with the numerical results. The age of the intrusive body at SSGF is estimated to be between 6000 and 20,000 years.