A Fractured Reservoir Simulator Capable of Modeling Block-Block Interaction

Abstract

ABSTRACT A new simulator has been developed to model displacement processes in fractured reservoirs, in particular the block-block interaction in gravity drainage processes. This block-block interaction forces oil draining from a matrix block into the fracture system to be absorbed by the underlying matrix block whenever this is possible. Otherwise the oil flows through the fracture network. Block-block interaction influences both the initial production rates and the resulting hydrocarbon distribution in the reservoir. Simulation of fractured reservoirs with this type of interaction between matrix blocks makes high demands upon the simulator, both in terms of memory requirements and speed. The simulator hence uses dynamic memory management and an efficient grid-block partitioning scheme that reduces the memory requirements significantly. In addition, this scheme enables a high degree of vectorisation on a Cray computer. The simulator can be used for a variety of reservoir geometries: dual porosity, dual porosity/ permeability, reservoirs with block-block interaction and unfractured reservoirs.