Publications

Common-Reflection-Surface (CRS) stack collects all the energy reflected from a subsurface interface defined by its Fresnel zone. By averaging those traces from the same reflection area into a stack trace, signal-to-noise ratio is improved by reinforcing coherent energy while random noise is cancelled in theory. In the surface, those traces not only belong to a one Common-Depth-Point (CDP) but involve several CDPs because of the Fresnel effect. 3D seismic land data employs CRS attributes searching sequences such as automatic CMP search to estimate stacking velocities, linear / plane wave and hyperbolic search to extract emergence angle, radius of curvature of hypothetical Normal (RN) and NIP-wave (RNIP). These attributes are called initial CRS attributes. A final refined attribute set is obtained by applying global optimization approach using simulated annealing. CRS attribute search is an iterative and redundant process that depends on previous search stages. An important stage in that process is determination of dip and azimuth, required for a plausible result within a reasonably economic turn-around time. This paper looks at a new approach to azimuth and dip determination as applied to a 3D land seismic and confirms its ability to improve the volume stack quality within feasible turn-around time. Keywords: 3D CRS-stack, turn-around time, azimuth and dip determination