Comparision of an analytic and a numerical approach for tracer transport in a fractured geothermal reservoir.

Between two wells in a fractured limestone geothermal reservoir the flow was investigated by two different methods in order to characterize tracer transport phenomena. The knowledge of reliable tracer transport simulation is a key issue to derive the petrophysical properties of geothermal reservoirs. In the first simulation the flow was considered in an equivalent plane fracture by the Hele-Show flow approach. The second method replaced the fractured system by an equivalent porous layer in which a Darcy flow develops. The Hele-Show flow is described by analytic complex variable functions, while the Darcy flow is determined applying finite difference simulation method. The obtained results are similar adequately. Especially the coincidence is very strong between the injection and production wells..