Petrophysical imaging using AVO

Seismic lithology is the process by which rock properties—such as lithology, porosity, and pore fluid content—are determined by analysis of seismic and other data. I emphasize other data because the seismic method is limited in what can be achieved in a vacuum, but can be remarkably robust when combined with other information and constrained by geologically reasonable assumptions. I define “petrophysical imaging” as a seismic lithology method which does not attempt to recover absolute rock properties but rather involves the construction of an image of subsurface rock property variation. For example, for direct hydrocarbon indication, absolute rock properties need not be determined, only the deviation from background nonpay behavior is required.