Skip to main content

Science – Society – Technology

Fig. 3 | Geothermal Energy

Fig. 3

From: An open-access stress magnitude database for Germany and adjacent regions

Fig. 3

Hydraulic pressure curves. a Schematic pressure curve of fluid injection tests (after White et al. 2002). FIT marks the stage in which the pumping is ceased in case of formation integrity tests, LOT marks the corresponding stage for leak-off tests. The continued curve is valid for hydraulic fracturing, mini-fracs and extended leak-off tests (XLOT). The pressure values to be picked are abbreviated as follows: LOP leak-off pressure, FBP/\(P_\text {b}\) formation breakdown pressure, FPP formation propagation pressure, ISIP/\(P_\text {si}\) instantaneous shut-in pressure, FCP fracture closure pressure, \(P_\text {r}\) reopening pressure. \(P_0\) is the pore pressure prior to pumping. b Schematic setup of (X)LOTs and FITs at the uncased bottom section of a borehole. c Schematic setup of hydraulic fracturing and mini-frac procedures in a packed borehole section

Back to article page