  This paper presents several test cases intended to be benchmarks for
numerical schemes for single-phase fluid flow in fractured porous media. A
number of solution strategies are compared, including a vertex and a
cell-centered finite volume method, a non-conforming embedded discrete fracture
model, a primal and a dual extended finite element formulation, and a mortar
discrete fracture model. The proposed benchmarks test the schemes by increasing
the difficulties in terms of network geometry, e.g. intersecting fractures, and
physical parameters, e.g. low and high fracture-matrix permeability ratio as
well as heterogeneous fracture permeabilities. For each problem, the results
presented by the participants are the number of unknowns, the approximation
errors in the porous matrix and in the fractures with respect to a reference
solution, and the sparsity and condition number of the discretized linear
system. All data and meshes used in this study are publicly available for
further comparisons.
