AVO interpretation

AVO interpretation analyzes seismic reflection amplitude changes across increasing offset (angle) to quantitatively predict subsurface rock properties (e.g., lithology, porosity) and identify fluid content, specifically hydrocarbons.

AVO (Amplitude Variation with Offset) interpretation is a proven, high-ranking technology for direct hydrocarbon detection (DHI) and reservoir characterization. The process analyzes how seismic reflection amplitudes change with increasing offset (angle), a variation governed by rock property contrasts (Vp/Vs, density) across an interface. Interpreters commonly use cross-plots of the zero-offset amplitude (Intercept, R0) versus the amplitude gradient (A1) to define AVO classes (e.g., Class 2, Class 3) and isolate fluid anomalies from background lithology. Initially applied successfully in the 1980s to detect gas in California sandstones, the technique now provides critical, quantitative information on lithology, porosity, and seal properties, significantly reducing exploration risk and reserves determination uncertainty.

https://wiki.aapg.org/Amplitude_versus_offset_(AVO)_analysis