The EERC’s efforts first focused on identifying the key elements of previous relevant work that could be brought to bear on achieving the goal of developing broadly and consistently applicable storage coefficients.
Storage resource classification and estimation schemes historically used by the U.S. Geological Survey (USGS), Petroleum Resource Management System, and the mining industry to assess the existence of hydrocarbon and mineral resources, as well as CO2-specific storage classification and estimation schemes proposed by the CSLF, DOE, USGS, and the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), were examined and evaluated.
These classification and estimation schemes were considered with respect to their applicability to both hydrocarbon reservoirs and saline formations.
The next step was to determine the parameters and factors that would affect the storage coefficient and, as a result, the estimation of the potential storage of any given assessment area.
To determine the effect of different parameters, the EERC drew upon the previous literature and ran a series of numerical simulations using models of different types of sedimentary rock formations under several types of structural settings.
These examinations and subsequent computer modeling and simulation work led to clarifications of the effects of different key parameters on CO2 storage under a broad range of geological conditions.
The ultimate culmination of these efforts was 1) the identification and refinement of equations for estimating CO2 storage resources for saline formations; 2) the development of coefficient values for such systems, representing a wide variety of geological features at scales ranging from small to very large; and 3) an approach for utilizing those equations and coefficients toward the development of technically defensible and consistent storage resource/capacity estimates.