DYNAMICS and ACTIVE PROCESSES - International Lithosphere ...

ILP TASK FORCE on SEDIMENTARY BASINS
2010 International Workshop
November 7-12, 2010, Tirana (Albania)
PLATFORM CARBONATE SUBTHRUSTS as MAJOR HYDROCARBON PLAYS in
NW ALBANIA - MONTENEGRO REGION
Zamir BEGA,
OMV PETROM S.A., Romania
e-mail: zamir.bega2@petrom.com
Until to date, most of the industry exploration efforts in the NW Albania-Montenegro region
(Fig. 1) have been focused either towards the thin-skinned thrust of Kruja-Dalmatian platform
carbonate ramps or outboard of Kruja-Dalmatian thrust front, searching for pelagic thrusted
ramps. Both approaches resulted unsuccessful despite abundant hydrocarbon shows in the
area. All deep wells drilled outboard of Kruja thrust front have TD at Tertiary deposits, failing
to reach the Mesozoic target.
The new data gathered by international industry during 90’s provides new insights to the
Mesozoic paleogeography and Mesozoic platform/basin morphology. Two major tectonic
units, which differ only in deformation style can be deciphered in onshore-offshore Albania-
Montenegro: the thick-skin deep seated platform to the west, partly inverted, as part of
Apulian foreland eastward ramp, and a wide zone to the east, characterized by the known
Kruja-Dalmatian thin-skinned ramps, running parallel to the coast line. JJ-3 well (offshore
Montenegro) is the only well that have been reached the thick skinned platform carbonates.
Delineation of the thick-skin platform margin towards the offshore-onshore Albania was
carried out based on new 2D seismic lines acquired during 90’s (Fig. 2).
The relationships between the thick-skinned platform carbonates and the thin-skinned ones
are product of pre-orogeny architecture and also foreland-ward contraction. Due to massive
westward overthrusting, the thin-skinned thrust belt has masked most of the deep seated paraauthochthonous
platform carbonates. A SE-NW orientation anticlinorium trend of deep paraautochthonous
platform carbonates is interpreted just north of Vlora-Diber Lineament (VDL).
The anticlinorium, which is draping over pre-Mesozoic basement and stretched out for about
140 km into onshore Montenegro, could hold several structural closures along strike. The
thick-skinned structuration is mainly due to post-Oligocene inversion, coincident with post
oligocene westward thrusting. The Kruja-Dalmatin thin-skinned ramps are draping over the
anticlinorum and mimicking the underlying topography, in dip and strike orientation. Deep
seated autochthonous platform carbonates in onshore western Albania region resemble the
Southern Apennines plays in Italy, where more than 3 billion OOIP have been discovered so
far from fractured carbonate reservoirs (Fig. 3).
The exploration of the thin-skinned thrusts plays of the platform carbonates is considered of
high risk mainly due to immature and insufficient Cretaceous SR to generate commercial HC
in such levels and also of high risk on sealing capacities. The deeply buried Cretaceous SR,
analogue to those contributed to Southern Appenines discoveries are modeled to generate the
necessary amounts of light oils, trapped into fractured shallow water carbonates reservoirs and
sealed by Oligocene regional seal (Fig. 4). Two major deep rooted transversal faults in the
area known in published literature as Scutari-Pec Lineament (SPL) and Vlora-Diber
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