... homogeneous axisymmetrical stress field with vertical axis, with local strong anomalies that correspond to either high or low stress magnitudes. Introduction In situ measurements are essential for characterising the natural stresses that exist in a rock mass and such a characterisation is required...

... different levels in the Oxfordian limestone. Upstream Oil & Gas day stress field Reservoir Characterization stress magnitude sedimentary paris basin pore pressure variation argillite limestone Magnitude pressure solution stress field principal stress direction reservoir geomechanics...

... Abstract Three measurement campaigns were carried out by Natural Resources Canada CANMET Laboratories over the last thirty years within the Red Lake Gold District, Ontario, to determine the magnitude and orientation of in-situ rock stresses on several levels of the Campbell and Red Lake gold...

... barely touch each other provides a unique way to determine the minimum principal stress magnitude. This hydraulic testing method has been adapted to measuring the pressure required to reopen mechanically a preexisting fracture of known orientation (HTPF method). Today, for crystalline rock formations...

... Reservoir Characterization accretionary prism sonic velocity reservoir geomechanics stress magnitude OHmax Upstream Oil & Gas Finland Johansson Chang stochastic approach principal stress misfit effective stress ln-5itu rock stress Magnitude Artificial Intelligence OHmin rock...

.... The maximum variation of stress magnitude and orientation is ca. 11 MPa and 70°. Brittle deformation zones were, however, modelled as best-fit planes and the effect of true discontinuous, curved I bending /undulating faults remains unclear until the next planned model revision. Additionally, local parameter...

... seismicity risk in the Pyhäsalmi mine. The expected maximum event size is found by clustering seismic data using the Quality Threshold and Single Linkage clustering algorithms, and applying the Gutenberg-Richter's frequency-magnitude relationship. Induced seismicity risk is assessed using the Quantitative...

... symposium evaluation method Upstream Oil & Gas stress result Magnitude fractured rock stress measurement FEM result principal stress 7th lntamatlonal Symposium on ln.Situ Rock S1ras8 May 1G-12, 2016, Tampera, Finland JohanMOn & R.aasakka (ed J ISBN 978-951-758-1Kl6-1 ISSN 0356-9403...

.... In particular, the time of ice cover and related forebulge, maximum thickness of the ice cover, and the retreat of the ice cover are considered. Modelling results demonstrate that the magnitudes and the stress drops of the induced seismic events associated with fracture slip tend to be the largest under stress...

... not be used to estimate stress magnitudes. The orientation of the maximum horizontal principal stress (S Hmax ) is determined to be NE-SW to -2000 mbsf, subparallel to the subduction margin between Philippine Sea plate and Eurasian plate. We attempt to estimate stress magnitudes assuming that the stress state...

... (CCBO) technique. Measurement period is from 1991 to 2015. Main results obtained in this study can be summarized as follows. The magnitudes of the three-dimensional principal stresses and the vertical stress at one year after the earthquake were more than double those before the earthquake...

... international journal stress estimation breakout principal stress Magnitude international symposium 7th International Symposium on ln-51tu Rock stress May 10-12,2016, Tampera, Finland Johansson & Raasakka (ads) ISBN 978-951-758-806-1 ISSN 0356-9403 INTEGRATED IN-SITU STRESS ESTIMATION BY HYDRAULIC...

... fracture Magnitude Abstract We have proposed a new concept in which the in-situ stress state is determined by integrating the hydraulic fracturing data and the deformation of core samples. The integration leads to improve practicality and compensate disadvantages compared with the case using each...

... to vary with the first stress invariant; effectively the confinement provided to the rock fabric. Measurements indicate that the elastic modulus in coal measure strata (elastic modulus range 3 GPa to 40 GPa) typically doubles in magnitude from an unconfined state to a maximum at a first stress invariant...

... of stress within, and beyond, the area affected by the stress concentration surrounding the excavation. When possible, hydraulic fracturing is used to provide independent information about the magnitude of the least principal stress, but is not used to estimate the maximum horizontal principal stress...

.... They raise the question on the origin of stresses in sedimentary formations and on spatial stress variations. Finally, consequences for integrating data collected at different depths in sedimentary formations are briefly discussed. reservoir geomechanics stress magnitude Zoback Cornet horizontal...

... of these phenomena disclosed during the excavation of the auxiliary tunnels and the underground testing sites. Based on these data, the multi-methods integration analysis is carried out to estimating the regime, orientation and magnitude of the in-situ stress at this site. The analysis indicates that the accuracy...

... range of crack density: 0.015 0.045 5 Proximity of fracture-criticality/ percolation threshold 6 Consistent SWVA in explor. surveys & above earthquakes Other field observations 7 Fracture-criticality specifies crack distributions with dimensions over 9 orders of magnitude 8 90 -flips of polarisations...

... maximum compression direction, which is in accord with the contemporary earthquake focal mechanism solutions, as well as the first order pattern of tectonic stress direction in the eastern Eurasian plate. The current stress tensor exhibits a heterogeneity in its orientations and magnitudes, possibly...

... ABSTRACT: This paper presents a case study of a deep-buried underground tunnel project with the buried depth of 1000 m in south-western China. Both the magnitude and direction of the geo-stress were determined through the field measurement. The stress distribution law of the tunnel...