title: Pre-site characterization risk analysis for commercial-scale carbon sequestration.
abstract: This study develops a probability framework to evaluate subsurface risks associated with commercial-scale carbon sequestration in the Kevin Dome, Montana. Limited knowledge of the spatial distribution of physical attributes of the storage reservoir and the confining rocks in the area requires using regional data to estimate project risks during the pre-site characterization analysis. A set of integrated Monte Carlo simulations are used to assess four risk proxies: the CO2 injectivity, area of review (AoR), migration rate into confining rocks, and a monitoring strategy prior to detailed site characterization. Results show a reasonable likelihood of reaching the project goal of injecting 1 Mt in 4 years with a single injection well (>58%), increasing to >70% if the project is allowed to run for 5 years. The mean radius of the AoR, based on a 0.1 MPa pressure change, is around 4.8 km. No leakage of CO2 through the confining units is seen in any simulations. The computed CO2 detection probability suggests that the monitoring wells should be located at less than 1.2 km away from the injection well so that CO2 is likely to be detected within the time frame of the project. The scientific results of this study will be used to inform the detailed site characterization process and to provide more insight for understanding operational and technical risks before injecting CO2.
authors.affiliation: Los Alamos National Laboratory, Los Alamos, New Mexico 87544, United States.
authors.forename: Zhenxue
authors.initials: Z
authors.lastname: Dai
authors.forename: Philip H
authors.initials: PH
authors.lastname: Stauffer
authors.forename: J William
authors.initials: JW
authors.lastname: Carey
authors.forename: Richard S
authors.initials: RS
authors.lastname: Middleton
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Lu
authors.forename: John F
authors.initials: JF
authors.lastname: Jacobs
authors.forename: Ken
authors.initials: K
authors.lastname: Hnottavange-Telleen
authors.forename: Lee H
authors.initials: LH
authors.lastname: Spangler
mesh_terms: D002245:Carbon Dioxide / Q000032:analysis; D057965:Carbon Sequestration; D003198:Computer Simulation; D016001:Confidence Intervals; D009009:Montana; D009010:Monte Carlo Method; D016062:Porosity; D018570:Risk Assessment; D035501:Uncertainty
chemical_list: D002245:Carbon Dioxide