| Abstract |
A conceptual model is presented to describe thermal recovery from a semi-infinite hot dry rock (HDR) geothermal reservoir containing an equidimensional permeable zone. Transient behaviour may be represented uniquely by five dimensionless parameters. Variation in production temperature (T,) with time ( tD) is influenced by reservoir throughput (Q,), thermal porosity (gD) and depth ratio (a/z). Of these, only throughput exercises significant control on transient performance, the parameter being directly proportional to reservoir circulation rate and inversely proportional to the effective radius of the stimulated zone. |