02461nab a2200193 4500 20260520000225.0 260224s2009 xxu Upscaling two-phase flow in naturally fractured reservoirs nov. 2009 17/06/2010 ; 17/06/2010 12 p. ; 1621-1632 Transcripción del resumen del autor. Simulation grid blocks of naturally fractured reservoirs contain thousands of fractures with variable flow properties, dimensions, and orientations. This complexity precludes direct incorporation into field-scale models. Macroscopic laws capturing their integral effects on multiphase flow are required. Numerical discrete fracture and matrix simulations show that ensemble relative permeability as a function of water saturation (kri[Sw]), water breakthrough, and cut depend on the fraction of the cross-sectional flux that occurs through the fractures. This fracture-matrix flux ratio (qf/qm) can be quantified by steady-state computation. Here we present a new semianalytical model that uses qf/qm and the fracture-related porosity (f) to predict kri(Sw) capturing that, shortly after the first oil is recovered, the oil relative permeability (kro) becomes less that that of water (krw), and krw/kro approaches qf/qm as soon as the most conductive fractures become water saturated. To include a capillary-driven fracture-matrix transfer into our model, we introduce the nonconventional parameter Af,w(Sw), the fraction of the fracture-matrix interface area in contact with the injected water for any grid-block average saturation. The Af,w(Sw) is used to scale the capillary transfer modeled with conventional transfer functions and expressed in terms of a rate- and capillary-pressure-dependent kro. All predicted parameters can be entered into conventional reservoir simulators. We explain how this is accomplished in both, single- and dual-continua formulations. The predicted grid-block-scale fractional flow (fi[Sw]) is convex with a near-infinite slope at the initial saturation. The upscaled flow equation therefore does not contain an Sw shock but a long leading edge, capturing the progressively widening saturation fronts observed in numerical experiments published previously. 11 AAPG Bulletin 93 ARTICULO Matthäi, Stephan K. 42975 Maghami-Nick, Hamidreza 42976 171187 171187 0 0 0 0 239006 BAAB BAAB 2026-03-05 200046045 0 200046045 2026-03-05 15:13:33 2026-03-05 ARTICULO