The Influence of Regional Uplift and Exhumation Upon Paleo and Active Petroleum Systems, Libya

Abstract

Some 46-48 billion barrels of oil have been found in Libya so far in granitic, clastic and carbonate reservoirs within a thick Phanerozoic succession. This succession was interrupted by a number of regional uplift and unroofing events during mid-Devonian, the early and late Carboniferous (‘Hercynian’), early and mid-Cretaceous (‘Austrian), and late-Eocene-early Oligocene, early Miocene, late Miocene and Plio-Pleistocene (Alpine’). These together have shaped its tectono-stratigraphic architecture into Palaeozoic intermontane basins and Mesozoic-Cenozoic extensional rifts. Several of these basins harbour prolific petroleum systems, variously influenced by the exhumation events. This ranged in intensity between those regions experiencing generally continuous subsidence with hydrocarbon accumulations only locally affected by fault reactivation and trap breeching at one extreme, to basins subjected to repeated unroofing and reburial leading to spillage, breeching, remigration and dispersal of pre-uplift paleo-accumulations at the other. The dynamic relationship between uplift and erosion, depressurizing, faulting and fracturing constrained expulsion timing, migration efficiency and direction, charge and post-charge modification of hydrocarbon accumulations within each province. The contrasting age and tectono-stratigraphic history of these provinces provides a robust template with which to assess the varying effect of exhumation upon petroleum systems productivity.

AAPG Datapages/Search and Discovery Article #90291 ©2017 AAPG Annual Convention and Exhibition, Houston, Texas, April 2-5, 2017