Simulation of multiphase flow in fractured reservoirs using a….pdfVIP

Comput Geosci (2010) 14:527–538 DOI 10.1007/s10596-009-9168-4 ORIGINAL PAPER Simulation of multiphase flow in fractured reservoirs using a fracture-only model with transfer functions Evren Unsal · Stephan K. Matthäi · Martin J. Blunt Received: 17 April 2008 / Accepted: 5 October 2009 / Published online: 13 November 2009 © Springer Science + Business Media B.V. 2009 Abstract We present a fracture-only reservoir simula- realistic fracture network. Waterflooding runs reveal tor for multiphase flow: the fracture geometry is mod- the fraction of the fracture–matrix interface area that is eled explicitly, while fluid movement between fracture infiltrated by water so that matrix imbibition can occur. and matrix is accommodated using empirical transfer The evolving fraction of the fracture–matrix interface functions. This is a hybrid between discrete fracture dis- area turns out to be an important characteristic of crete matrix modeling where both the fracture and ma- any particular fracture system to be used as a scaling trix are gridded and dual-porosity or dual-permeability parameter for capillary driven fracture–matrix transfer. simulation where both fracture and matrix continua are upscaled. The advantage of this approach is that the complex fracture geometry that controls the main Keywords Fractured reservoirs · flow paths is retained. The use of transfer functions, Countercurrent imbibition · Dual porosity · however, simplifies meshing and makes the simula- Finite element/finite volume method tion method considerably more efficient than discrete fracture discrete matrix models. The transfer functions accommodate capillary- and gravity-mediated flow be- 1 Introduction tween fracture and matrix and have been shown to be accur