4-D Analogue
Modeling
of Transpressional Structures Growing in a Rheologically Heterogeneous Medium: Methodology, Main
Results and Reference Models
Marchal, Denis1, Jean-Marc Daniel2, Misael Alvear1 (1) Petrobras Energia Venezuela, Caracas, Venezuela (2) Institut Français du Pétrole, Rueil Malmaison, France
The study of the evolution of complex geological structures,
such as the transpressive one of La Concepción field in modeling
. At
IFP this
modeling
methodology is completed by the use of non-destructive
techniques of acquisition with CT-scanner (4D imaging), allowing the geologist
to follow, in space and time, the deformation of the structures growing in the
experiments.
During this project, twenty-two experiments have been performed
to describe the tectonic evolution of a rheologically
contrasted sedimentary cover lying over a stepover
formed by two overlapping basement faults, reactivated by transpressional
tectonics. Thirty-three 3D blocks of selected experiments have been interpreted
(horizons and faults). These 3D models illustrate the main geometrical
characteristics of the different fault networks generated and their evolution
through time (4D approach). The analysis of these
experiments has highlighted the main tectonic phenomena occurring in this
tectonic setting and the principal parameters that control them.
The study shows
that the La Concepción field structure best matches
with a tectonic model involving transpression with a
moderate amount of shortening, including a partial decoupling between the lower
and the upper part of the structure. Moreover, all the models might be used as
references (database) for the geologist interpreting seismic
data in problematic
zones (structural complexity, scarce or noisy data) and to constantly test the
structural model elaborated with the field data.