Slowness-Domain Moveout and Residual Moveout for Orthorhombic Layered Media
Z. Koren and I. Ravve
Event name: 81st EAGE Conference and Exhibition 2019
Session: Poster: Anisotropy and Fractured Reservoirs A
Publication date: 03 June 2019
Info: Extended abstract, PDF ( 625.73Kb )
Price: € 20
Considering compressional and converted waves, we first derive approximations for the kinematical characteristics (radial and transverse offset components, traveltime and intercept time) in the slowness domain, for layered orthorhombic models. We expand the slowness surface into a series in the proximities of both the normal incidence ray and the critical (horizontal) ray, and we compute the coefficients of these series. We propose a continuous approximation function for the radial offset, valid for the entire slowness range, whose series expansions match the computed coefficients. Approximations for the other characteristics are derived from the radial offset. The residual moveout formula is obtained by keeping the intercept time identical for the background and updated (perturbed) models, and we relate the error of the vertical time (residual moveout) for a given horizontal slowness magnitude and azimuth with the residuals of the effective parameters, such as the normal moveout velocity, effective anellipticity and asymptotic properties of the updated model.