Journal of Petroleum Geology, vol.
26
(
4
), October
2003
, pp
451
-
464
Copyright 2003 by Scientific Press Ltd. All rights reserved.
BURIAL HISTORY RECONSTRUCTION AND THERMAL MODELLING AT KUH-E MOND, SW IRAN
M. R. Kamali
1 and
M. R. Rezaee
2
1 Research Institute of Petroleum Industry, NIOC, PO Box 18745/43163,Tehran, Iran.
email: [email protected]
2 Tehran University, Faculty of Science, Geology Dept., Tehran, Iran.
email: [email protected]
At the Kuh-e Mond anticline (Fars Province, SW Iran) and in nearby offshore structures,
large volumes of natural gas are reservoired in the Permian — Early Triassic Dehram
Group while heavy oil has been discovered in the Cretaceous Sarvak and Eocene Jahrum
Formations. In this paper, we use data from six exploration wells and from nearby surface
exposures to reconstruct the burial history at Kuh-e Mond. Regional observations show
that the thick sedimentary fill in this part of the Zagros Basin was subjected to intense
tectonism during the Zagros Orogeny, with a paroxysmal phase during the late Miocene
and Pliocene. Thermal modelling and geochemical data from Kuh-e Mond and adjacent
fields allows possible hydrocarbon generation and migration mechanisms to be identified.
Maturities predicted using Lopatin’s TTI model are in accordance with maturities obtained
from vitrinite reflectance measurements.
We show that formations which have source potential in the nearby Dezful Embayment
(including the Pabdeh, Gurpi, Gadvan and Kazhdumi Formations) have not reached the
oil window in the Mond wells. Moreover, their organic carbon content is very low as they
were deposited in oxic, shallow-water settings. Underlying units (including the Ordovician
and Cambrian) could have reached the gas window but contain little organic matter.
Silurian shales (Sarchahan Formation), which generate gas at Kuh-e Gahkum and
Kuh-e Faraghan (north of Bandar Abbas) and in Saudi Arabia and elsewhere in the
Middle East, are absent from the Mond structure.
The absence of source rocks suggests that the gas and heavy oil accumulations at Kuh-e
Mond and at nearby fields have most probably undergone long-distance lateral migration
from distant source kitchens.