An Innovative Method of Quantifying Channel Distribution in a Frontal Splay Environment Using Shallow Seismic-Reflection Data

Armitage, Dominic A.¹, Thad P. Dunbar², Henry W. Posamentier² (1) Stanford University, Stanford, CA (2) Anadarko Petroleum Corporation, Houston, TX

Analysis of three-dimensional channel density and distribution in deep-water frontal splay (i.e., submarine fan or lobe) deposits allows for creation of detailed analogs using high-resolution, shallow seismic-reflection data. These analogs can provide significant insights with regard to risk mitigation in exploration and field development. The analysis involved first slicing through the deposits using horizon slices or proportional horizon slices. Channels were mapped at 2-4 msec intervals and then statistically analyzed. The method of channel quantification involved a combination of seismic interpretation and attribute extraction software in concert with Microsoft Excel and Spotfire to assess the spatial evolution of individual, resolvable channel elements within each frontal splay. A number of visualization techniques are applied to the data to display the three-dimensional connectivity based on the channels identified within frontal splays. Channel distribution within the splays show a Gaussian distribution down the fan (parallel to transport direction) and a near Gaussian distribution across the fan (orthogonal to transport direction).

The statistical data extracted from high-resolution examples of frontal splay deposits is used to objectively characterize proximal, medial and distal parts of this type of depositional element. The results of this study can be applied 1) to mitigate risk for reservoir presence and distribution within geometrically and lithologically similar depositional elements at exploration depths, where data resolution is poorer, and 2) to assist in reservoir modeling; populating reservoir simulators with analog-derived statistics should lead to more accurate flow simulations.