| Abstract |
As part of the geothermal energy program at Stanford University, physical models have been developed to evaluate optimum performance of fracture-stimulated geothermal reservoirs. Three such efforts reported in this summary are: laboratory simulation of an explosion-produced rubble chimney to obtain experimental data on the extract ability of heat from hot rock by in-place boiling; heat and mass transfer transients with individual porous rock fragments to compare their relative importance in stimulated systems; and measurement of radon emanation from geothermal reservoirs as a tracer for reservoir engineering studies. Definitive progress has been achieved with each of these physical models. Hunsbedt, Kruger, and London (19 Sa) reported the progress on the construction and operation of a 19-ft.3 laboratory model of an explosionproduced rubble chimney (shown in the production mode in Fig.1.5) to study the processes of in-place boiling, moving flash fronts, and two-phase flow in porous and fractured hydrothermal reservoirs, It had been noted by Ramey, Kruger, and Raghavan (1973) that all though considerable energy is available from hydrothermal resources, most of this energy is stored in the aquifer host rock. Production by some nonisothermal process, such as in-place boiling or colder fluid recirculation, might be valuable for increasing heat extraction from natural or stimulated hydrothermal or hot rock geothermal resources. |