System and method for characterizing fractures in a subsurface reservoir

The disclosed methods, systems, and software are described to optimize fracture characteristics and simulate fluid flow rates in a well model. The well model, which includes at least one fracture intersecting a production well, was generated using static and dynamic data such as measured fluid flow rates from the fractures into the well. Fluid flow in the well model is simulated to obtain simulated fluid flow rates between fractures and the well. Fracture properties, such as length, height and aperture, are then updated responsive to the measured and simulated fluid flow rates. Multiple simulation runs and updating of the fracture properties can be performed until the simulated fluid flow rates converge with the measured fluid flow rates.; Pressure data can be used to determine gridblock permeability, which in turn helps constrain the model, thus providing more reliable fracture properties. Uncertainty ranges of the fracture properties can also be calculated.