Figure 2
Stress field investigations. a). Stress polygon for a reservoir depth of 4,000 m TVD. Different stress regimes are illustrated (NF normal faulting (green), SS strike-slip faulting (yellow), TF thrust faulting (red)) with differential stress ratios (Anderson 1951) for μ = 0.85 (solid line) and (Bachmann et al. 1987) for μ = 0.6 (dotted line). The red dotted line describes the lower threshold for Sh as obtained from FIT and cementation pressure data. The blue asterisk shows the stress tensor combining both stress polygons for μ = 0.6 as well as μ = 0.85 and the Sh values resulting from FIT and cementation pressures. b). Stress profiles: pore pressure (Pp) for a groundwater level of 225 m and a pressure measurement at 3,450 m TVD result in a gradient of 9.814 MPa /km to 2.25 MPa; vertical stress (Sv) for a mean density of the overburden of 2.3 g/cm3; minimal horizontal stress (Sh) gradients for the FIT data in the greater Munich area (Sh/FIT) and minimal horizontal stress gradient from cementation pressures at the Sauerlach wells (Sh/Cem.); reservoir sections for Th1, Th2, and Th3 (black dotted and solid lines).