Unconventional seismic for unconventional reservoirs

Bryan DeVault, Vecta Oil & Gas Ltd.

Seismic predictions of attributes such as silica or clay content, carbonate or organic matter fraction, or brittleness are popular techniques for characterizing resource plays.  Two of the most commonly used parameters, Young’s Modulus and Poisson’s Ratio, are often obtained from prestack inversion of P-wave seismic data.  Because those quantities depend on the Vp/Vs ratio and/or density, their accurate estimation, even with prestack inversion, is problematic on land seismic data:  all of the shear information in conventional seismic data resides in the noisy far angles of the seismic data.  Unfortunately, recovering density requires estimation of the even noisier AVO curvature term.  These issues become much less severe if multicomponent seismic data is added to the inversion because of the additional shear information contained in multicomponent data, thereby offering a much better path to accurately recovering Young’s Modulus, Poisson’s Ratio, or other elastic properties useful for reservoir characterization in conventional or unconventional settings.  This approach is demonstrated on several 3D seismic datasets from a variety of plays in the Rockies, Mid-Continent, and Permian Basin where knowledge of the elastic properties or the presence of natural fracturing was essential for reservoir prediction.

Bio

Bryan DeVault received B.S. degrees in physics and mathematics from the University of Houston in 1990 and a Ph.D. in geophysics from the Colorado School of Mines in 1998. He was an exploration geologist/geophysicist for Shell International from 1998 to 2001 in the Netherlands and a senior exploration geophysicist at Anadarko Petroleum Corporation in Houston from 2001 to 2003.  He is currently President and CEO of Vecta Oil & Gas Ltd. in The Woodlands, Texas, where he has worked since 2003.   His professional interests include seismic data processing and inversion, sequence stratigraphy, amplitude vs. offset (AVO) analysis, and reservoir prediction using multicomponent seismic data. He is an active member of AAPG and the Society of Exploration Geophysicists.