Large-scale flow of geofluids at the Dead Sea Rift

Buoyancy-driven flow associated with salinity variations is proposed as the principal driving force that has caused large-scale migration of brine and hydrocarbons at the Dead Sea Rift. Numerical simulations indicate the coexistence of two basin-scale groundwater flow systems, one atop the other, with opposite flow directions. The first is a density-driven migration of brine through deep aquifers from the rift outward, which has affected hydrocarbon maturation and migration, and the formation of three small gas fields. The second is a topography-driven groundwater flow through relatively shallow aquifers from the surrounding highlands toward the rift valley, which has caused oil biodegradation, forming heavy oils and asphalts. Simulations indicate that flow-field configurations of both groundwater and hydrocarbons have changed during the structural evolution of the rift, illustrating the interrelationships between basin formation, paleohydrology and hydrocarbon reservoir formation. (C) 2000 Elsevier Science B.V. All rights reserved.