Integration of Discrete Feature Network Methods with Conventional Simulator Approaches

Abstract

The discrete feature network (DFN) approach offers many key advantages over conventional dual porosity (DP) approaches, particularly when issues of connectivity dominate recovery and reservoir stimulation in fractured and heterogeneous reservoirs. DP models have been developed for complex multiphase and thermal effects, and have been implemented for basin scale modeling. However, DP models address only the dual porosity nature of fractured reservoirs, generally simplifying connectivity and scale-dependent heterogeneity issues which are modeled efficiently and more accurately by the DFN approach. This paper describes the development of techniques to integrate DFN and DP approaches. These techniques allow the analyst to maintain many of the advantages of the DP simulator approach without losing the realism of complex fracture system geometry and connectivity, as captured by DFN models. The techniques described are currently used within a DOE funded research project for linking a DFN and a DP thermal simulation model for the Yates Field, Texas. The paper describes some of the geological and engineering aspects of the Yates Field and gives two examples how DP parameters for the thermal simulation can be derived using DFN modeling techniques. P. 351

Integration of Seismic Anisotropy and Reservoir Performance Data for Characterization of Naturally Fractured Reservoirs Using Discrete Feature Network Models

“…Various authors 4,5 have developed techniques for upscaling of permeabilities given a generalized discrete fracture distribution. Dershowitz et al 5 used finite element 16 simulation to construct permeability tensors for each individual simulator block.…”

“…Various authors 4,5 have developed techniques for upscaling of permeabilities given a generalized discrete fracture distribution. Dershowitz et al 5 used finite element 16 simulation to construct permeability tensors for each individual simulator block. This technique involves gridding of a discrete characterization of the fracture-matrix system, and successively simulating the flow through each block under appropriate boundary conditions.…”

“…More recently, Lough et al 4 developed boundary element computational methods for computing the effective permeability of fractured reservoirs. Dershowitz et al 5 developed permeability upscaling methods for discrete fracture networks using finiteelement computational techniques.…”

“…However, none of these yet provide as robust a solution to the generalized multi-phase problem as the finite difference dual porosity formulation. Finite element methods implemented by Dershowitz et al 5 allow use of Discrete Feature Network (DFN) models of fracture distributions for more 'realistic'…”

Simulation of shale gas transport and production with complex fractures using embedded discrete fracture model

“…Such fracture geometries are inadequate to represent the complex nature of fracture geometry in reality. Similarly, the traditional dual‐continuum (dual‐porosity or dual‐permeability) numerical models have the limitations for explicitly modeling complex fractures and cannot adequately account for anisotropy, heterogeneity, and fracture connectivity …”