Constant normal-moveout (CNMO) correction: a technique and test results

We introduce a processing technique which minimizes the 'stretching effects ' of conventional NMO correction. Unlike conventional NMO, the technique im plies constant normal moveout (CNMO) for a finite time interval of a seismi c trace. The benefits of the proposed method include preservation of higher frequencies and reduction of spectral distortions at far offsets. The need for severe muting after the correction is reduced, allowing longer spreads for stack, velocity and AVO analysis. The proposed technique has been test ed on model and real data. The method may improve the resolution of CMP sta ck and AVO attribute analysis. The only assumptions for this stretch-free N MO correction are (i) all time samples of a digital reflected wavelet at a particular offset have the same normal moveout, and (ii) reflection records have an interference nature.