Prediction of Reservoir Properties in Deep-Marine Channel-Levees

Ben Kneller¹, Ahmed Kassem¹, Ian Kane², and Mason Dykstra^3
1 University of Aberdeen, Aberdeen, United Kingdom
² University of Leeds, Leeds, United Kingdom
³ University of California, Santa Barbara, CA

Submarine channel-levee systems can form extremely large and well-connected systems. Although typically rather low net-to-gross, their sheer size means that they may contain prodigious quantities of sand, and form significant reservoirs for oil, condensate and gas. Characterization of the reservoir depends upon good quantitative models for the variation in sand across the levee, and establishing ways to calibrate subsurface systems to these models.

We have examined deep water levee systems at a variety of scales, in order to characterize their gross geometry and internal properties. In particular, we have characterized the variation in properties of a large-scale levee system associated with a late Cretaceous continental slope channel system in Baja California, Mexico, and a small-scale channel within a late Carboniferous paleo-fjord in San Juan province, Argentina. We conclude that most slope channel systems show a power-law decay in thickness moving outwards from the channel (in contrast to basin floor channel systems, which apparently show an exponential thickness decay). This reflects a similar decay in thickness of the individual beds within the levees. Net-to-gross typically decays exponentially away from the channel. We believe these models can provide robust predictions of reservoir properties in the subsurface where the levee has not experienced significant gravitational collapse.