Abstract: A method for producing oil and/or gas from an underground formation comprising locating a suitable reservoir in a subsurface formation; creating a model of the reservoir; populating the model with laboratory data; modeling the reservoir to determine fluid displacements based on fluids injected and fluids produced; determining an optimum fluid mixture for the fluids to be injected based on a series of sensitivity analyses performed with the model; drilling a first well in the formation; injecting the optimum fluid mixture into the first well; drilling a second well in the formation; and producing oil and/or gas from the second well.