17 - Modelling the effects of faults and fractures on fluid flow in petroleum reservoirs

Abstract

Fault and fracture zones are often highly-complex heterogeneities that can have a significant effect on fluid flow within petroleum reservoirs on length scales of less than 1 μm to more than 10 km. It is therefore important to incorporate their properties in production simulation models. The chapter describes some of the numerical techniques being used to model the effects of faults and fractures on fluid flow. Some of the techniques that are being developed to model flow around faults acting as barriers to fluid flow are described in the chapter. At the millimetre scale, the Markov chain Monte Carlo simulation can be used to construct the 3D pore structure of fault rocks, which may then be combined with the lattice Boltzmann method to determine their permeability. A discrete fault flow model is presented for modeling fluid flow around highly-complex fault zones at the kilometre scale. The results from these models can then be incorporated directly into industry-standard production simulation models to allow better decision-making. To model reservoirs where faults and fractures act as conduits for fluid flow, the chapter also presents a discrete fracture model.