Abstract
This paper argues that any capacity estimation method requires a combination of geological, engineering and economic analysis in order to provide rigorous capacity estimates. It also argues that the classification of capacity estimates should follow concepts in the existing SPE Petroleum Resource Management System as closely as possible. The Energy & Environmental Research Centre (EERC) (Gorecki et al., 2009) have developed a definition of "practical storage capacity" that parallels the definition of petroleum reserves as "the quantity of hydrocarbons which are anticipated to be commercially recovered from known accumulation at a given date forward", but the EERC acknowledge that there is currently a problem with implementing a price of carbon. This paper develops the economic analysis further than the EERC. Like the EERC, we demonstrate that analytical and numerical injectivity modelling based on geological models of the subsurface can help determine practical storage capacity.
In doing this, the paper makes observations about methods for estimating storage capacity, shows results of reservoir simulations and economic analyses, draws on SPE and internationally accepted methodologies and definitions of petroleum resources and discusses how equivalent definitions can be applied to storage capacity. Finally, the paper provides recommendations for an improved CO2 storage capacity classification system.
