| Title | Interpretation of Tracer Return Profiles at Wairakei Geothermal Field Using Fracture Analysis |
|---|---|
| Authors | Fossum, Martin P.; Horne, Roland N. |
| Year | 1982 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; New Zealand; Wairakei; Enthalpy; Flow Rates; Injection; Tracer Analysis; Reinjection Wells |
| Abstract | Tracer tests performed in geothermal reservoirs have indicated inter well flows at speeds up to 100m/hr. Such rapid movement of injected water underground indicates a clear danger of premature thermal breakthrough during reinjection. Early thermal drawdown has in fact been observed in several fields. The very rapid returns suggest that fractures are the principal conduits for tracer transport and thus a new method of tracer profile interpretation has been formulated. This method is based on flow through individual fractures rather than through porous medium as has been the case in standard methods. Applications of the method to tracer tests performed at the Wairakei geothermal field show excellent matching of the observed tracer profiles based on a model of only two fractures joining the injection and production wells. |