Publication Date:
2022-04-29
Description:
Petrophysical properties of rocks and their applicability at larger scale are a challenging topic in
Earth sciences. Petrophysical properties of rocks are severely affected by boundary conditions, rock
fabric/microstructure, and tectonics that require a multiscale approach to be properly defined. Here we
(1) report laboratory measurements of density, porosity, permeability, and P wave velocities at increasing
confining pressure conducted on Miocene foredeep sandstones (Frosinone Formation); (2) compare the
laboratory results with larger-scale geophysical investigations; and (3) discuss the effect of thrusting on the
properties of sandstones. At ambient pressure, laboratory porosity varied from 2.2% to 13.8% and P wave
velocities (Vp) from 1.5 km/s to 2.7 km/s. The P wave velocity increased with confining pressure, reaching
between 3.3 km/s and 4.7 km/s at 100 MPa. In situ Vp profiles, measured using sonic logs, matched the
ultrasonic laboratory measurement well. The permeability varied between 1.4 × 10 15m2 and 3.9 × 10 15m2
and was positively correlated with porosity. The porosity and permeability of samples taken at various
distances to the Olevano–Antrodoco fault plane progressively decreased with distance while P wave
velocity increased. At about 1 km from the fault plane, the relative variations reached 43%, 65%, and 20% for
porosity, permeability, and P wave velocity, respectively. This suggests that tectonic loading changed
the petrophysical properties inherited from sedimentation and diagenesis. Using field constraints and
assuming overburden-related inelastic compaction in the proximity of the fault plane, we conclude that
the fault reached the mechanical condition for rupture in compression at differential stress of 64.8 MPa at a
depth of 1500 m.
Description:
Published
Description:
9077-9094
Description:
2IT. Laboratori sperimentali e analitici
Description:
JCR Journal
Description:
open
Keywords:
Petrophysical properties of sandstone
;
04. Solid Earth::04.04. Geology::04.04.09. Structural geology
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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