Dr. Hardage has worked with the Department of Energy for several decades assisting with shear wave seismic interpretation of fracture systems in "cap rock" earth layers targeted for potential CO2 sequestration reservoirs.
Recent application of the VertiShear Technology by way of analyzing first arrival SV-P reflections that are recorded by vertical geophones in 3D seismic data have generated accurate azimuth of maximum horizontal stress (SHmax) predictions at all reservoir depth boundaries of interest.
When compared to SHmax results from P-P amplitude-vs-incident-angle (AVA) analysis, which has been the industry standard application, the VertiShear SV-P SHmax analysis had more accurate results at deeper targets than PP AVA in all instances across a 24 square mile survey.
Results of this D.O.E. funded study are the subject matter of several articles currently under peer review and in process to be published in the SEG's Interpretation journal for 2021.
Determining fast-S and slow-S propagation directions with SV-P data
Interpretation / May 2021
Estimating SHmax azimuth with P sources and vertical geophones: Use P-P reflection amplitudes or use SV-P reflection times?
Interpretation / submitted for publication
An example of azimuth-dependent SV-P arrival times at a series of 5 stacking bins.
Histograms comparing SV-P SHmax estimates to PP AVA SHmax estimates. The SV-P method continued to produce the best quality and correct prediction of SHmax at the deepest targets where PP AVA could not.