Most water injection wells in waterflooded reservoirs have fractures that grow with time. These fractures can have a significant impact on the reservoir performance (oil production rates, o/w ratio and ultimate recovery).

A single well model that predicts the length of injection well fractures by modeling fracture growth due to fracture face plugging and thermal stresses is coupled with a reservoir simulator to simulate injection wells that have fractures that dynamically grow with time. The relative importance of the injected water quality, formation permeability, injection rate and the temperature of injected water on the rate of fracture growth are demonstrated. The single well model accurately accounts for all the physics of fracture growth at the injector while the reservoir simulator accounts for the large-scale reservoir structure.

The presence of high conductivity fractures in the injectors affects the waterflood sweep efficiency. Results indicate that fracture orientation, rate of fracture growth, injection water quality and reservoir heterogeneity play an important role in determining the oil production rates and ultimate recovery. The results of the simulations can be used to set injection well pressures and rates, specify water quality and to select injection well patterns to maximize oil recovery.