Modeling episodic dewatering and evolution of fluid pressure/total load ratio (lambda) in a sedimentary basin

This contribution presents a two-dimensional modeling study of fluid releas e from an overpressured compartment at depth towards a shallower aquifer. A transient fluid how model is applied to simulate the evolution of fluid fl ow taking into account the effects of synchronous consolidation created by the fluid pressure release. The evolution of the ratio between fluid pressu re and total load, denoted as lambda, is calculated during the dewatering o f a sediment pile. Results show that the fluids are drained from the overpr essured compartment and flow into shallower aquifers, thereby creating elev ated values of lambda in shallower zones, indicating favorable conditions f or hydrofracturing. Simulation results suggest a zipper-like propagation of hydrofracturing conditions towards shallower depths. (C) 2000 Elsevier Sci ence B.V. All rights reserved.