Efficient simulation of hydraulic fractured wells in unconventional reservoirs

In this paper, we present efficient numerical methods to handle both long-term well performance and transient behavior simulations for hydraulic fractured wells in unconventional reservoirs with a coarse grid. To simulate correctly the long-term behavior, transmissibilities around the fracture and the connection factor between a fractured block and the fracture are computed, based on a (pseudo)-steady-state near-fracture solution. This approach provides not only an accurate long-term well production calculation, but also a correct pressure distribution in the near-fracture region. In unconventional reservoirs, the transient effects cannot be ignored, due to the very low reservoir permeability and near-well/near-fracture physical processes such as fracturing fluid induced formation damage. In order to handle the transient effect, the coupled modeling technique is used, and its efficiency is demonstrated with a tight-gas reservoir.