Deep-Water Depositional Systems: Processes and Products

Modern outcrops and subsurface data sets provide a mapping opportunity to characterize deep-water depositional systems from shelf edge to basin plain. This includes observations of the grain- to basin-scale framework and key stratigraphic surfaces that subdivide the basin-fill. Analysis from recent mapping campaigns (2009-2020) from over 20 stratigraphic intervals in the Americas, Europe and Asia-Pacific yields the following insights.

1. The range and variability in deep-water siliciclastic conventional petroleum reservoirs includes deposits resulting from transport and deposition via fluid turbulence, matrix strength and a combination of those two mechanisms.
2. Sediment distribution patterns in the deep sea are controlled by several key factors including various aspects of grain size and sediment volume, gradient, accommodation and overall basin type.
3. Sub-bed-scale, semi-quantitative analysis of sedimentary fabric ratios commonly gleaned from core and image logs reveals critical information on bulk rock volume, net:gross and porosity to help determine stock tank original oil in place (STOOIP).
4. Sedimentary provenance and source-to-sink routing systems are intimately linked to overall reservoir presence and reservoir quality in fine-grained turbidite reservoirs.
5. Downslope sediment gravity flow behavior can be used to calibrate and understand the predictive attributes in deep-water reservoir type from canyon head to basin plain.

The results of these mapping campaigns reveal new observations on sediment gravity flows, their processes of transport and sedimentation, and their bearing on oil and gas exploration and development in deep-water depositional systems. This presentation incorporates observations from passive margins including faulted slopes and ponded mini-basins, and active margins including foreland, forearc, back-arc, strike-slip, intracratonic and hybrid basins.