247 8. Seismic anisotropy applied to geothermal prospection 8.5 From anisotropy to fracture attributes The relationship between anisotropy and fracture is not direct; a lateral change of any property affecting the impedance (lithology, porosity, fluid, …) may lead to the same effect. To derisk the anisotropy interpretation, a lateral gradient computed on each of these predicted properties should be calculated (Baillet et al., 2024). This attribute captures their lateral variation rate. Cut-off values can be proposed to mask the anisotropy anomalies where a property is changing too much; in remaining areas, the high anisotropy has been interpreted as fracture density. In the illustration below, Figure 8.4, the remaining high anisotropy, in red in the bottom section, are interpreted as fracture density from the original anisotropy volume, in colors in the top section. Figure 8.4 Example of derisking anisotropy attribute when other reservoir properties are stable.
RkJQdWJsaXNoZXIy NjA3NzQ=