In order to make robust and informed interpretations of seismic amplitudes, to develop a predictive rock physics framework, we need to understand the geological controls on the elastic properties of each seismically distinct rock type that may be present within the basin; we also need to understand if some rocks can’t be imaged. The geological properties that we are interested in, and those that control elastic properties, include the rock mineralogy, porosity, fluid saturation, depth of burial, and compaction state, as well as pore pressure and stress. To make this connection we need to turn to rock physics.
In order to establish links between the geological properties of interest and the seismic responses observed away from well control, we often turn to well data. In frontier basins, well control is often limited, and as a consequence, understanding the geological signal behind the seismic observations can be difficult.
In this paper, discussion of the key considerations that should be made when developing a predictive rock physics framework is provided. This is illustrated by reference to an example from the Canadian Atlantic margin (see Huntbatch, et al 2016). Detailed information on this regional study can be found on the Nalcor Energy website.
Once this framework is in place, we can generate multiple scenarios by perturbing the geological parameters of interest; these scenarios can then be used to inform seismic interpretation. Finally it should be noted that the type of work described here forms one element of the de-risking workflow and should be considered in conjunction with other geoscience disciplines when evaluating a prospect.
