The Use of Interval Velocities as a Seismic Attribute

The use of seismic velocities as an attribute related to hydrocarbon presence is not as common as amplitude-derived attributes (e.g. AVO) because the interpretation of interval seismic velocities depends on a range of subsurface properties such as lithology, porosity, pore pressure and fluid content. High-resolution interval velocities can be used as a seismic attribute because low velocity anomalies can be related to light hydrocarbon content. To complement the use of seismic velocities to detect hydrocarbon traps, we propose two different interval velocity-derived attributes, instantaneous acceleration and secondary velocity. Low velocity anomalies can be better delineated by using a crossplot between both attributes thereby reducing significantly the interpretation uncertainty. In this abstract we report a case study using these new attributes which suggests the presence of a reservoir of light oil or gas.