Lunchbox Geophysics

Making Shear-Wave Statics Actual Statics: a Ray Path-Consistent Approach

Raul Cova

Raul Cova
University of Calgary

Tuesday, April 12th, 2016 – 12:00 PM
Chevron auditorium, +15 level of 500 – 5th Avenue SW

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LunchBox Geophysics is free! Simply bring your own lunch (refreshments provided) and enjoy.

Abstract

Removing near-surface effects in the processing of 3C data is key to exploiting the information provided by converted waves. Conventionally this is done under the assumption of surface consistency. However, if the velocity change between the low velocity sediments at the near surface and the medium underneath is smooth, the vertical ray path assumption that supports the surface-consistent approach is no longer valid. This feature results in a non-stationary change of the near surface effects that needs to be addressed in order to properly solve the problem. In this study a ray path-consistent approach is used to correct the S-wave near-surface effects. This is achieved by transforming the data sorted in receiver gathers to the tau-p domain and performing cross-correlation and convolution operations to capture and subtract the near-surface effects from the data. Results show that this processing improves coherency and stacking power of shallow and deep events simultaneously. Shallow events, in particular, benefited most from this processing due to their wider range of reflection angles. Synthetic and field data processing will be presented to illustrate these ideas.

Biography

Raúl Cova received his B.S. Degree in Geophysics in 2004 from Simon Bolivar University in Venezuela. He then worked for PDVSA in different positions, starting in Western PDVSA in 2004 as a Field Geophysicist and then as an R&D Geophysicist for PDVSA Intevep between 2005 and 2012. In 2010 he received a Graduate Diploma in Petroleum Geosciences from IFP School. Raúl joined CREWES in September 2012 to pursue a Ph.D. degree in Geophysics at the University of Calgary. His research interests are multicomponent seismic data processing, interferometry and full waveform inversion.