Estimating Stress from Three-Dimensional Borehole Displacements Induced by Fluid Injection in Different Types of Fractured or Faulted Rocks

We analyze the displacement, fluid pressure and injection flowrate data measured during hydrofracturing (HF) tests conducted in intact foliated metamorphic rock at 1490.5 m depth in the Sanford Underground Research Facility (SURF, USA), and at 485 m depth in the central Scandinavian Caledonides (Sweden). Through the comparison with other methods also implemented on these sites, we find that one SIMFIP test may be "sufficient" to estimate the full stress tensor's orientation and magnitude. We also observe that when a natural discontinuity activated, its properties must be considered in the analyses otherwise stress magnitudes may be significantly over-estimated.