AbstractHydraulic fracturing in tight, naturally fractured reservoirs is a difficult process and qualifying effectiveness in such an environment is complicated. Through evaluation of naturally fractured shale and naturally fractured sandstone case studies, we will show how hydraulic fracturing effectiveness in naturally fractured reservoirs can be qualified. For this evaluation, we will use lumped and fully three-dimensional (3D) hydraulic fracturing models, analytic bottomhole treating pressure analysis techniques, analytical reservoir models, and finite-difference reservoir simulation. When used together, these techniques can characterize negative effects that can occur to the natural fracture system during the hydraulic fracturing process. These effects relate to the extent of natural fracturing, permeability anisotropy, pressure dependent leakoff, and natural fracture damage.