| Abstract |
The location of fccd poitits in wells atid tlic tratisport palhs of injected fluid are dominated by the presence of fractures in a geothermal reservoir. As the cold water passes tlirougli the hot rock, it is heated, and may be recoveredat production wells for power production as hot liquid or steam. It is important that sufficient heat transfer between the fluid and rock occurs before the injected fluid is recovered at a production well in order to prevent premature thermal breakthrough. Several modeling techniques are available for assessing the migration of cold water fronts through geothermal reservoirs (Bodvarsson, 1972; Pruess ef al., 1987; Bodvarsson and Tsang,1982; Woods and Fitzgerald, 1993). However, only porous medium type models of fluid flow and heat transfer in geothermal reservoirs have been rigorously tested by laboratory experiments (Fhgerald and Woods, 1994; Woods and Fitzgerald, 1995, 1996). In this paper we report upon a series of laboratory experiments which have been conducted in order to test the theoretical models for liquid injection and heat transfer within liquid-dominated and vapourdominated fractured geothermal reservoirs. We find that the analytical solution for the liquid-dominated case of radial flow, and numerical solution for the vapour-dominated case, agree very well with the experimental results. |