Abstract: Injection into a subterranean formation is optimized using a computation model to optimize injection. An optimization objective is to maximize the cumulative fluid mass rates injection that span over the remaining life of the field, while maintaining a dense or supercritical phase and operating within the equipment operational parameters. The phase at each location may be determined based on pressure and temperature, and flow is dynamically adjusted to maintain a phase having at least a threshold density of the carbon dioxide injected at each injection location.