Core Lab operates a full-service geomechanics laboratory that provides customers with multi-frequency
acoustic velocities, elastic properties and engineering analyses that revolutionize log calibration.
Rock strength is typically 20-60% of that predicted by high frequency measurements. These high frequency
measurements give information about elastic properties, but cannot foretell plastic deformability or
brittle behavior. In order to accurately reflect rock mechanical properties, logs must be calibrated
with low and ultra-low (static) frequency data that can only be obtained in the laboratory.
Conventional dipole sonic logs are combined with lab measurements and transformed into powerful multi-frequency
Both P-wave (compressional) and S-wave (shear) velocities increase as frequency increases from low frequency to seismic
to logging and ultrasonic frequencies. Calibration with only ultrasonic data causes overestimation of velocities at
lower frequencies. Elastic moduli change dramatically with frequency, whereas Poisson's ratio varies less.
Knowledge of acoustic velocities in reservoir rocks under changing pore pressures and fluid states secures important data
for drilling, completion, and geophysical applications in difficult geologies.