Structural Analysis of Recent Hydrocarbon Discoveries in the Berkine Basin: Characterization and Process-Based Predictive Modeling

By

W. Lansing Taylor¹

(1) Anadarko Petroleum Corporation, The Woodlands, TX

 Over 3 billion barrels of recoverable oil have been discovered in the Berkine Basin of Algeria since 1990. One component of exploration success has been the identification of faults that provide migration pathways and structural closure. Understanding the timing, vertical and lateral continuity, and hydraulic behavior of these faults is fundamental to understanding the hydrocarbon system. We have developed a procedure for predicting vertical fault continuity in layered rock, and have successfully applied it to understand the distribution of hydrocarbon types in this basin. The technique integrates documented rheological heterogeneity with a three-dimensional effective stress model to predict the presence or absence of faulting in specific depth ranges under applied tectonic loads. The calculated mechanical threshold where discrete fault segments should link together to breach regional seals corresponds to the documented onset of vertical migration, confirming our predictive model. Our approach provides a mechanical rationale supporting the interpretation of downward dying and vertically segmented faults in areas of ambiguous seismic data, and suggests a robust method for evaluating gas risk in this dominantly oil-producing region. As a corollary, these results illustrate that Andersonian or kinematic models force unrealistically complex interpretations. Advances in structural characterization using continuum mechanics have yielded insights on local fault patterns and their relationship to regional tectonics that are inconsistent with such traditional interpretation techniques. This further suggests a simplified tectonic model for the Berkine Basin can adequately captures the kinematic fault history and the variability in structural style, but with far fewer tectonic events.