
TY  - JOUR
A1  - Pretzschner, Carsten 
A1  - Lindner, Harald 
A1  - Rohler, Hendrik 
T1  - In-situ formation stress determination using sonic logs and In- Borehole-Tomographic-Reconstruction of the near-borehole shear wave distribution
JF  - ASEG Extended Abstracts
JO  - ASEG Extended Abstracts
Y1  - 2004
VL  - 2004
IS  - 1
SP  - 1
EP  - 4
KW  - 
UR  - https://doi.org/10.1071/ASEG2004AB117 
N2  - For advanced borehole logging interpretation of cross-dipole shear wave sondes with `In-Borehole-Tomographic-Reconstruction' techniques an effective method for the determination of the mechanical stress distribution in the formation was developed. The method includes the reconstruction of the 3D-shear wave velocity distribution in the immediate surrounding area of the borehole formation with tomographic algorithms. The composition of the stress-induced shear wave velocity and comparison to the modelling results allow a quantitative interpretation. This log of the local formation stress anisotropy is excluded from both caliper-effects and the influences of shear wave velocity anisotropies caused by sedimentary effects. As examples, logs of ratios of the local minimal/maximal formation-stress amplitudes DSh/SH(z) were generated in a range of 0.86-0.99 for two gas production boreholes. 
ER  -

