Introduction With a high demand of hydrocarbon worldwide, conventional oil production is quickly approaching its peak. Inevitably, heavy oil and bitumen (ultraheavy oil) will emerge as “new” (so-called unconventional) hydrocarbon resources because of their tremendous potential. Currently, more than 50% of Canada’s oil production is from heavy oils (Alboudwarej et al., 2006; Hinkle and Batzle, 2006). Such heavy oils are highly viscous, difficult to move in reservoirs, and much more expensive to produce. In addition to mining and other cold production methods, many different techniques (e.g., thermal, chemical, or in situ combustion, etc.) have been applied to mainly reduce viscosity and assist the heavy-oil production. None of these techniques have matured completely yet, and engineering developments are occurring rapidly. These techniques remain expensive in terms of energy and resources used (lots of water) and in terms of efficiency and overall environmental impact. The steam-assisted gravity drainage (SAGD) technique is a current popular technique. In a steam chamber, more than 60% of oil in place can be produced (Caruso, 2005; Gupta, 2005). However, on a reservoir scale, efficiency can be low (approximately 15% with different resources). Clearly, seismic techniques hold great potential for assisting reservoir characterization and recovery monitoring. Monitoring has been demonstrated successfully in several fields [Cold Lake (Eastwood et al., 1994) and Duri Field, Indonesia (Jenkins et al., 1997)]. However, to be effective, we must understand the seismic properties of the heavy oils and the heavy-oil sands. This understanding of in situ properties is the key to bridging the seismic response to reservoir properties and changes. Schmitt (2004) provided a general review of rock physics as related to heavy-oil reservoirs. Here, we examine the seismic properties of heavy oils in detail.

Abstract Lithology and fluid information can be extracted from seismic data of deepwater clastics if their relative contribution to the signal is understood. Brushy Canyon Formation outcrop seismic models are constructed for the Western Escarpment of the Guadalupe Mountains using properties from outcrop, normal, and overpressured Gulf of Mexico and North Sea basins to test seismic sensitivity to lithology, fluid, and pressure. Large, clean, gas-saturated, and overpressured sandstones have the best resolution. Hydrocarbon saturation does not necessarily enhance seismic response. Lithology and fluid effects can reduce impedance contrast, resulting in low amplitudes (dim spots). Elevated geopressures preserve porosity producing low velocities and high amplitudes (bright spots). Even in low-impedance contrast intervals, offset-dependent amplitudes increase resolution and indicate hydrocarbons.