The Stability of Two-phase Geothermal Reservoirs

.n a number of geothermal systems, including the 3eysers (Ca), Lardarello (Italy) and Tongonan :Philippines), well logs indicate that in some parts of he reservoir, a two-phase vapouror liquid-dominated -egion is overlain by a colder liquid saturated zone. The stability of such systems is intriguing. Schubert md Straus (1980) have described how a liquid layer nay overly a model superheated vapour zone if there IS a sufficiently large conductive heat flux through the system. However, real geothermal systems involve a :wo-phase boiling zone below the liquid layer. This may be an important difference.