Motivations

Obtaining multiparameter elastic depth images from seismic reflection data is a key step toward seismic reservoir characterization. High-resolution maps of elastic properties may be directly indicative of lithology, physical states such as pressure or temperature, or pore fluid constituents (Parsons, 1986). Careful calibration of seismic attributes to physical properties measured in situ at boreholes can aid in monitoring Enhanced Oil Recovery (EOR) projects, such as steam injection or in situ combustion (Greaves and Fulp, 1987). These examples suggest applications in hydrocarbon exploration (including direct hydrocarbon detection), reservoir extension, and reservoir production.

Furthermore, there is a widespread notion that seismic properties such as P and S impedance may correlate well with other more elusive earth properties, such as porosity, permeability, sand/shale content, or sand thickness. Often, secondary parameters such as porosity are not directly ascertainable from seismic reflection data, but can be measured in situ at reservoir zones. If a few robust parameters can be extracted from seismic reflection data, then perhaps their geostatistical correlations to measured secondary parameters such as porosity can be used to interpolate or extrapolate borehole measurements over a large seismic survey area (Doyen, 1988). These applications suggest implications for reservoir management, including constraints to flow simulations, design and implementation of production and EOR strategies, and refined calculation of net pay volumes. Extracting reliable elastic parameter estimates from seismic reflection data would be an important challenge in achieving these goals.