Using Temperature Signals to Estimate Geometry Parameters in Fractured Geothermal Reservoirs
F. Maier1 P. Oberdorfer1 I. Kocabas2 I. Ghergut1 M. Sauter1
1Dpt. Applied Geology, Center of Geosciences, Georg-August-University, Göttingen, Germany
2Petroleum and Natural Gas Engineering Department Batman, Batman University, Batman, Turkey
We compare the output of 2D single fracture models as well as analytical solutions of the problem. The temperature signal is evaluated with the heat transfer mode while the flow field is assumed to exhibit Darcy flow everywhere. The problem is time-dependent so we have to take into account a change in the boundary conditions from a Dirichlet to a Neumann condition which is activated at the time of change from the injection to the withdrawal phase. A numerical dispersion problem is encountered at the abrupt temperature change at the thermal front. Hence the resolution in time and space is the numerical "bottleneck" of the problem. The accuracy due to numerical dispersion depend on the cell Peclet number.