Analysis of tracer test data, and injection-induced cooling, in the Laugaland geothermal field, N-Iceland

Tracer tests in geothermal resource management

“…Figure 9 shows production temperature predictions calculated by a pessimistic model based on the tracer recovery simulation presented in Figure 8. They show that the long-term cooling of the borehole in question should be minimal, in particular in view of the considerable increase [19]. Spent geothermal fluid was reinjection into borehole LJ-08 and production from borehole LN-12 about 300 m away.…”

“…• C) in N-Iceland, conducted in 1997, simulated by the method presented above [19]. This was during initial reinjection testing in the field, since then reinjection has been part of the management of the system.…”

“…Figure 9. Estimated production temperature decline of borehole LN-12, due to flow through the three channels simulated, for three cases of average long-term reinjection into borehole LJ-8 and an average long-term production rate of 40 L/s [19].…”

“…in productivity of the Laugaland system when reinjection is applied [19]. The final interpretation example is from the Los Azufres high-temperature geothermal system (reservoir temperature ∼280…”

Tracer Interpretation Using Temporal Moments on a Spreadsheet

“…a Some workers have used tracer tests to constrain numerical models, using the data to estimate heat transfer parameters (e.g., Robinson and Tester 1984;Axelsson et al 2001), or to constrain reservoir-scale numerical models (e.g., Gunderson et al 2002;Bloomfield et al 2003). However, the vast majority of these tests were interpreted qualitatively, ignoring the temporal evolution of the tracer breakthrough curve and resulting in gross test interpretation (e.g., size of the arrow indicative of relative tracer flow).…”