Defining the store : geological interpretation and storage modelling

The identification of a suitable storage site for CO2 is fundamental to a viable CCS methodology. In this chapter we describe a workflow for the process of identification, interpretation and geological modelling of a potential aquifer storage site. The construction of a valid and testable geological model is an essential pre-requisite to carrying out any reservoir simulation of CO2 flow and storage capacity modelling. A well constructed model enhances confidence in the numerical simulations and monitorability assesment and importantly, also delivers a visual understanding of the sub-surface to the nongeologist. Geologists visualise geology in 3D and previously have translated this onto 2D maps and sections. Modern technology now permits the routine construction of digital models at all scales and for these to be exported to other software packages. The construction of models based on limited data is, by necessity, open to multiple interpretation; and one of the key outcomes of our investigation has been to recognise the importance of the development and early application of a set of first response tools for geological interpretation and storage modelling. Use of this methodology and tool set should lead to best available data analysis, improved decision making and confidence in reservoir simulation (see Glossary for a full definition of terms used in this chapter).