Recent advances in risk assessment and risk management of geologic CO2 storage

Abstract

6This paper gives an overview of the advances made in the field of risk assessment and risk management 7 of geologic CO 2 storage (GCS) since the publication of the IPCC Special Report on Carbon Capture and 8Storage in 2005. Development and operation of a wide range of demonstration projects coupled with 9 development of new regulations for safe injection and storage of CO2 has led to development and 10 deployment of a range of risk assessment approaches. New methods and tools have been developed for 11 quantitative and qualitative risk assessment. These methods have been integrated effectively with 12 monitoring and mitigation techniques and deployed in the field for small-scale field tests as well as 13 large-scale commercial projects. An important development has been improved definition of risks, 14 which can be broadly classed as site performance risks, long-term containment risks, public perception 15 risks and market risks. Considerable experience has now been gained on understanding and managing 16 site performance risks. Targeted research on containment risks and induced seismicity risks has led to 17 improved understanding of parameters and processes influencing these risks as well as identifying key 18 uncertainties that need to be targeted. Finally, significant progress has been made to effectively 19 integrate communication strategies with risk management approaches to increase stakeholder 20 confidence in effectiveness of deployed risk management approaches to manage risks. 21

Risk, Liability, and Economic Issues with Long-Term CO2 Storage—A Review

“…If there are no lateral seals in addition to this primary seal, the CO 2 can still migrate more or less horizontally along the underside of the caprock until it is trapped or finds a pathway to escape the storage reservoir (Szulczewski et al 2012;Birkholzer et al 2015). Geologic uncertainty concerning the pathways that injected CO 2 and pressurized or displaced formation fluids will take is a major contributor to uncertainty in estimates of potential risk (Oldenburg et al 2009;Pawar et al 2015).…”

“…This contrasts with far lower (or approximately zero) costs of passive pressure management, where the pressure is allowed to normalize through natural migration of the in situ fluids out of the reservoir, the slow dissolution of the CO 2 into those fluids, or some other natural mechanism. If active pressure management is necessary but the costs of this important method of risk mitigation are prohibitive, then a substantial portion of the technically accessible storage resource (TASR) may not meet economic feasibility criteria for CO 2 storage capacity under current regulations (Schrag 2009;Birkholzer et al 2012Birkholzer et al , 2015Breunig et al 2013;Heidug 2013;Cihan et al 2014;Bachu 2015;Pawar et al 2015).…”

“…1 can be expressed as a probability. Proponents of GCS will probably also have to deal with perceived risk, which includes the technical risk, additional considerations of the nature of the hazard, and (subjective) perceptions of the impacts if it occurs (Ayyub 2003;NAS 2013;Pawar et al 2015). According to , a hazard of leakage associated with GCS can be quantified as a probability of exceeding an acceptable volume or rate of leakage of CO 2 , brines, and/or total dissolved solids (TDS) out of the storage reservoir.…”

“…However, they will need more complete information concerning the potential risks, liabilities, and associated costs, in order to make better comparisons with other low-or zero-carbon (green) energy technologies (which compete with CCS for government support). The probabilities of significant risk events associated with long-term CO 2 storage could be extremely low (Pawar et al 2015), and national-and other high-level assessments of CO 2 storage capacity (e.g., U.S. Geological Survey Geologic Carbon Dioxide Storage Resources Assessment Team [USGS] 2013) typically assume that any risks will be mitigated through brine extraction, other forms of active pressure management, and(or) other risk-minimizing strategies. Risk mitigation for geologic carbon storage (GCS) projects could be costly yet necessary to allay public concerns.…”

“…Impacts will be greater the higher the concentration of humans and other receptors within the areal extent of the CO 2 plume and the area of elevated pressure, which could extend far beyond the borders of plume migration (IPCC 2005;Price and Smith 2008;IEAGHG 2009;Rutqvist 2012; National Academy of Sciences [NAS] 2013; Birkholzer et al 2015;Pawar et al 2015).…”