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.