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Sedimentary Facies
and Fracturing in the Upper Cretaceous Apulian Platform Carbonates of the Murge
Foreland and
Di Cuia, Raffaele1,
Claude Gout2, Massimo Sarti3, Loic Balzagette4 (1)
G.E.Plan Consulting, Italy, Ferrara, Italy (2) Total E&P Syrie, Damascus,
Syria (3) Polytech.
The Upper Cretaceous Apulian Carbonates of the Murge foreland
and of the
The selected outcrop analogues present same age interval,
similar depositional system, and were deposited in the same paleo-climatic
conditions than the subsurface reservoirs. The architecture of the platform is
provided by the stacking of multiple-order stratigraphic cycles of tidal
origin. At the lithozone scale, the variability in thickness and facies is in
the range of tens of kilometres. At the facies scale, variability is much more
pronounced, with variations in the range 100-300 meters. Individual
depositional elements may significantly change their geometric and facial
characters in 10-100 meters.
Fracturing is less pervasive in the foreland Murge outcrops than
in the Maiella mountain. Fine-grained sedimentary
facies have by higher fracture densities, fracture sets are often sub-parallel
and bed-confined and represent bed-parallel conduits. Laterally discontinuous
coarse rudist associations and coarse-grained sedimentary facies are
characterised by scarce fracturing. All sedimentary facies are connected by
fractures that cross and connect several intervals. In this way, a dense
network of fractures and matrix porosity can be connected.
The
relationships between facies and fracturing show similar characteristics in the
two outcrop analogues even if they lie in two different tectonic settings
(foreland and thrust belt). This observation is fundamental for extrapolation
to subsurface reservoirs: it implies that fracture distribution in carbonate
reservoirs like the Apulian platform is relatively independent of the tectonic
regime but is strongly influenced by facies.