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 coex istence of two basin-scale groundwater flow systems, one atop the other, wi th opposite flow directions. The first is a density-driven migration of bri ne through deep aquifers from the rift outward, which has affected hydrocar bon maturation and migration, and the formation of three small gas fields. The second is a topography-driven groundwater flow through relatively shall ow aquifers from the surrounding highlands toward the rift valley, which ha s caused oil biodegradation, forming heavy oils and asphalts. Simulations i ndicate that how-held configurations of both groundwater and hydrocarbons h ave changed during the structural evolution of the rift, illustrating the i nterrelationships between basin formation, paleohydrology and hydrocarbon r eservoir formation. (C) 2000 Elsevier Science B.V. All rights reserved.