Probabilistic evaluation of shallow groundwater resources at a hypothetical carbon sequestration site

Abstract

Carbon sequestration in geologic reservoirs is an important approach for mitigating greenhouse gases emissions to the atmosphere. This study first develops an integrated Monte Carlo method for simulating CO2 and brine leakage from carbon sequestration and subsequent geochemical interactions in shallow aquifers. Then, we estimate probability distributions of five risk proxies related to the likelihood and volume of changes in pH, total dissolved solids, and trace concentrations of lead, arsenic, and cadmium for two possible consequence thresholds. The results indicate that shallow groundwater resources may degrade locally around leakage points by reduced pH and increased total dissolved solids (TDS). The volumes of pH and TDS plumes are most sensitive to aquifer porosity, permeability, and CO2 and brine leakage rates. The estimated plume size of pH change is the largest, while that of cadmium is the smallest among the risk proxies. Plume volume distributions of arsenic and lead are similar to those of TDS. The scientific results from this study provide substantial insight for understanding risks of deep fluids leaking into shallow aquifers, determining the area of review, and designing monitoring networks at carbon sequestration sites.

Impact of excessive groundwater pumping on rejuvenation processes in the Bandung basin (Indonesia) as determined by hydrogeochemistry and modeling

“…Understanding and predicting these processes at basin scale entails developing and integrating knowledge of hydrogeochemical characteristics, aquifer heterogeneity, and field-scale parameterizations, and then simulating a groundwater flow model (Dai et al 2010(Dai et al , 2014. One of the impacts of excessive groundwater pumping is to cause changes in the groundwater rejuvenation process.…”

Application of a new reduced‐complexity assessment tool to estimate CO2 and brine leakage from reservoir and above‐zone monitoring interval (AZMI) through an abandoned well under geologic carbon storage conditions

“…This study employs the Well Leakage Analysis Tool (WLAT) – a collection of reduced‐physics and reduced‐order models developed to estimate potential brine and CO 2 leakage rates through abandoned wells . The WLAT is a suite of predictive tools developed through the US Department of Energy's National Risk Assessment Partnership (NRAP) – an initiative to develop defensive, science‐based methodologies and tools to quantify risk profiles at geologic carbon storage sites .…”

Progress in monitoring strategies for risk reduction in geologic CO2 storage

“…Risk-driven strategic monitoring design will evaluate technologies for detection of key variables associated with risk, and will develop monitoring strategies and protocols using the output from tools quantifying risks and uncertainties, such as the NRAP integrated assessment models (IAM) and reduced order models (ROM) (Carroll et al, 2014;Dai et al, 2014;Zhang and Pau, 2012;Pawar et al, 2015). Strategic monitoring research provides insight into the most effective approaches to evaluate technologies, based on consideration of geologic site variability (DOE, 2013a;Pevzner et al, 2012;Peters, 2007).…”