Salt Tectonics and Central Persian Gulf Petroleum Plays

Stefano Carruba¹, Cesare Perotti², Giuseppe Bertozzi¹, Giorgio Bolis¹, Tesfaye Lakew¹, and Mostafa Naini^3
1Edison S.p.A, Milano, Italy
²Dipartimento di Scienze della Terra, Pavia University, Pavia, Italy
³NIOC, National Iranian Oil Company, Tehran, Iran

The area of the current Persian Gulf is part of the Arabian Platform, a huge basin developed on the Arabian Plate from Paleozoic to present. Its northeastern margin was deformed during the Zagros orogenesis (Oligocene-present); the rest remained unaffected by diastrophic events during the last 600 ma. The main structures are represented by low-relief anticlines which resulted from the reactivation of basement horst and formation of salt domes and diapirs (Hormuz salt). Although these structures are of paramount economic importance, bearing most of the hydrocarbons in the region, basement reactivation and particularly salt tectonics in the Persian Gulf basin is incomparably less known than that of other salt-bearing basins (Gulf of Mexico, North Sea). Interpretation of central Persian Gulf seismic profiles indicates that the depth of basement is in excess of 10-12 km and the sedimentary cover is characterized by parallel, flat-lying horizons locally deformed by salt pillows and diapirs. Tectonic activity was dominated by salt movement and uplift, apparently not driven by regional overburden extension. A basically continuous growth history of Hormuz salt pillows/diapirs since the lower Paleozoic is documented by structural analysis. Salt tectonic seems to have strongly controlled sedimentation patterns (local highs and lows), trap formation and disruption. Observations from our study can contribute to define a tectonic evolutionary model of the basin that could be integrated with other data to best explain the occurrence of the known HC accumulations and new plays in terms of source rock distribution and maturation, migration paths and trap formation.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece