Development of improved caprock integrity analysis and risk assessment techniques

GeoMechanics Technologies has completed a geomechanical caprock integrity analysis and risk assessment study funded through the US Department of Energy. The project included: a detailed review of historical caprock integrity problems experienced in the natural gas storage industry; advanced coupled transport flow modelling and geomechanical simulation of three large-scale potential geologic sequestration sites to estimate geomechanical effects from large-scale CO2 injection; and development of a quantitative risk and decision analysis tool to assess caprock integrity risks. Historical data from gas storage operations and CO2 sequestration projects suggest that leakage and containment incident risks are on the order of 10(-1) to 10(-2), which is higher risk than some previous studies have suggested for CO2. Geomechanical analysis, as described herein, can be applied to quantify risks and to provide operating guidelines to reduce risks. The risk assessment tool developed for this project has been applied to five areas: The Wilmington Graben offshore Southern California, Kevin Dome in Montana, the Louden Field in Illinois, the Sleipner CO2 sequestration operation in the North Sea, and the In Salah CO2 sequestration operation in North Africa. Of these five, the Wilmington Graben setting represent the highest relative risk while the Kevin Dome setting represents the lowest relative risk. (C) 2014 The Authors. Published by Elsevier Ltd.