Radon in Geothermal Reservoir Engineering

Abstract

Radon is a potentially - useful internal tracer for the study of geotherrral reservoi r s (Stoker and Kruger, 1975; Kruger, Stoker, and Umana, 1975). The naturally - occurring gaseous radioactive element radon exists essentially as the lonest - lived isotope, 3.83-day 222Rn, produced by alpha decay of 1620-year 226Ra, which in turn is produced in the natural uranium series originating with 4.5xl09-year 238U. Thus radon, which decays with its characteristic half - life of 3.83 days when separated from its parent radium, will be produced "forever" from the radium found rather uniformly distributed in crustal rocks at a mean concentration of about 1 pg/g/. However, radium as a chemical homolog of the alkaline earth elements calcium, strontium, and barium, can undergo hydrothermal processes in geothermal systems and may bere distributed in a geothermal reservoir.