Abstract: The Special Value of Seismic Attributes
BROWN, ALISTAIR R., Consulting Reservoir Geophysicist
Seismic attributes are extracted from a 3-D seismic data volume for two different purposes: they provide deeper insight and finer detail in pursuit of structure and qualitative stratigraphy and they can also provide reservoir property maps when tied to well control.
The multiplicity of attributes available today can be classified on the basis of their relationship to time, amplitude, and frequency. Attributes can also relate to gross properties, the vertical distribution of properties, or a selected value.
Time-derived attributes help with the details of structural interpretation. Patterns distinguish between geology and seismic noise. Coherence, residual, dips and azimuth are the most useful attributes in this category.
Amplitude-derived attributes help with stratigraphy and reservoir properties. Tracked horizons should be used wherever possible. Composite amplitude is particularly useful. Windowed amplitude can be helpful but is subject to geological contamination. Energy half-time has been successfully used for assessing vertical sand distribution.
Frequency-derived attributes also help with stratigraphy and reservoir properties but their reliability is uncertain. Geologic frequency is often masked by the frequency of the propagating wavelet. Some case history experiences, however, show that frequency attributes can be useful in revealing additional layering and thus more reservoir.
AAPG Search and Discovery Article #90937©1998 AAPG Annual Convention and Exhibition, Salt Lake City, Utah