The representation of faults in hydrocarbon flow simulation models

Tom Manzocchi

UCD Dublin

Monday 23rd February 2015

15:30:00

Aula Saleri VI Piano MOX - Dip, Matematica Politecnico di Milano

Geological faults are three-dimensional volumes, but are represented in oil-industry standard finite difference flow simulators as geometrical discontinuities between cells. This form of representation is necessary because although fault zones occupy a volumetrically insignificant part of an oil reservoir, an adequate volumetric representation of fault zones would require an unfeasibly large number of grid-cells. Instead, various forms of up-scaling have been developed to include faults in flow models of clastic reservoirs. Low permeability fault rock can be included as transmissibility multipliers, and full-field production history-matching results provide support for the algorithm developed to do this. Two-phase fault rock properties (saturation-dependent relative permeability and capillary pressure), and three-dimensional flow paths within fault zones caused by displacement partitioning, can both be key to reservoir performance in certain situations, but are not routinely considered in full-field modelling. In the presentation we will review how faults in clastic sequences are handled in numerical flow simulators in the petroleum industry, and outline approaches designed to improve this. contact: luca.formaggia@polimi.it // marco.verani@polimi.it