Scaling Foam Flow Models in Heterogeneous Reservoirs for A Better Improvement of Sweep Efficiency

Abstract

Summary In heterogeneous formations foam is expected to reduce mobility more in high permeability layers hence to divert flow towards low permeability regions. This has been shown experimentally by several authors by comparing core-scale foam displacements on core plugs of contrasted average permeability and by using a two-dimensional laboratory pilot consisting of two layers with different properties. More recently, it has been shown experimentally and theoretically that the foam mobility reduction scales approximately as the square root of permeability within the framework of Darcy-type semi-empirical foam flow models. This scaling law for the effect of permeability on foam properties was inferred from an analogy between foam flow in porous media and foam flow in capillary tubes and was found consistent with the modelling of available experimental data. This foam selectivity effect should improve the sweep efficiency and is of primary interest for liquid or gas diversion in improved oil recovery and environmental rem ediation. However, it is not yet accounted for in physical modelling and reservoir simulation rock-typing best practices nor used as a daily routine for the design of foam pilots. As such, the use of physical foam mobility reduction scaling law is highly recommended for foam process evaluation and is the purpose of the present communication. This work assesses the impact of such effects with large-scale Darcy-type foam comprehensive modelling upon designing pilot tests. A model implemented in IFP Energies nouvelles reservoir simulator PumaFlow is considered herein for the only purpose of demonstrating the impact of foam selectivity. We work out two-dimensional cross-sectional inter-well porous media of various permeability distributions and a three-dimensional synthetic reservoir, eventually. We demonstrate by varying the permeability contrast how off-target foam flow conventional modelling can be toward this permeability selectivity effect that drives fluids diversion and sweep efficiency if not properly accounted for. Finally, we show how selective foam injections can be designed in order to make the best joint use of the considered foam and the porous medium permeability heterogeneity.