AUTHORS.pdf

Erwin W. Adams, John P. Grotzinger, Wesley A. Watters, Stefan Schro¨der, David S. McCormick, and Hisham A. Al-Siyabi conducted a study on the digital characterization of thrombolite-stromatolite reef distribution in a carbonate ramp system in the terminal Proterozoic Nama Group, Namibia. The team used digital surveying technologies to map the stratigraphic architecture of the carbonate ramp system, which consists of a shoaling-upward ramp sequence with thrombolite-stromatolite reefs developed at several stratigraphic levels.

The reefs are associated with grainstone and heterolithic facies and exhibit diverse geometries and dimensions related to their position in the sequence-stratigraphic framework. The team collected sedimentological and stratigraphic data digitally in an extensive canyon system, allowing for a comprehensive documentation of the three-dimensional architecture and dimensions of the reefal buildups.

The study used both deterministic and stochastic methods to extend outcrop observations and construct 3-D models that honor the observed stratigraphy. The final 3-D model faithfully reproduces the outcrop distribution of facies and geological objects and has a high spatial resolution compared to petroleum industry reservoir models.

The organization of the reefal buildups in the stratigraphic framework has direct implications for reservoir continuity and connectivity in analogous settings. The digital characterization and 3-D outcrop models presented in this article can be used to condition dynamic reservoir-simulation modeling of geologically similar areas.

Key findings include:

Thrombolite-stromatolite reefs developed at several stratigraphic levels in the carbonate ramp system
Reefs exhibit diverse geometries and dimensions related to their position in the sequence-stratigraphic framework
Digital surveying technologies allowed for comprehensive documentation of the 3-D architecture and dimensions of the reefal buildups
3-D models constructed using deterministic and stochastic methods faithfully reproduce the outcrop distribution of facies and geological objects
* The organization of the reefal buildups has implications for reservoir continuity and connectivity in analogous settings.