Methods for estimating subsurface volumes in porous and permeable geologic formations are routinely applied in oil and gas,
ground water, underground natural gas storage, and UIC disposal evaluations.
In general, these methods can be divided into two categories: static and dynamic.
The static models require only rock and fluid properties, while the dynamic methods require information about active injection, e.g. injection volumes and reservoir pressures.
The static models are volumetric and compressibility; the dynamic models are decline curve analyses, mass (or volumetric) balance, and reservoir simulation.