Integrated
Structural and Fracture Modeling of a Structurally Complex Reservoir, Llanos
Foothills,
David R. Richards1,
German Meza C2, Alberto Ortiz F3
(1) Midland Valley, Golden, CO (2) TSP,
Bucaramanga, Colombia (3) Instituto Colombiano del Petroleo, Bucaramanga, Colombia
Production in the structurally complex Cupiagua field is at high rates from generally low porosity
sandstone units, suggesting that fractures make a major contribution to the
production. Maximizing the production through the life of the field depends on
an understanding of the fracture network and its connectivity. The primary
objective of this study was to integrate all significant data and apply it to
create fracture models, which aid in optimizing production.
A well-defined structural model is
critical as a first step to understanding fracture sets, sub-seismic scale
faults and the sequence of fracturing. 2D and full 3D balancing was performed
on a 3D interpretation to test and insure a valid model. Once the validity of the
model was established, detailed analysis of the geometric and strain attributes
of the key mapped horizons provided the base for fracture modeling. The second
key component of the modeling was analysis of fracture populations interpreted
from 22 image logs, followed by integration of these data and core data with
the deformation history. Key fracture characteristics that define the model
include: intensity distribution, orientation and deviation of orientation, stratigraphic and spatial distribution.
Fracture sets and a proposed fracture
history were determined from the combined image log, 3D structural analysis and
deformation history. The modeled 3D fracture networks take into account the
observed fracture characteristics in wells, the deformation history, and
geometric and strain characteristics of the unit. This integrative approach to
structural and fracture modeling provided geologically reasonable fracture
models and yielded insights for development.
AAPG Search and Discover Article #90063©2007 AAPG Annual Convention, Long Beach, California