A Simplified 1-D Model for Calculating CO2 Leakage through Conduits

Zhang, Y. ; Oldenburg, C.M.

关键词: 54;    58;    ATTENUATION;    CAP ROCK;    FORTRAN;    OSCILLATIONS;    PERMEABILITY;    STORAGE;   

DOI  :  10.2172/1006401
RP-ID  :  LBNL-4266E
PID  :  OSTI ID: 1006401
Others  :  TRN: US201106%%868

美国|英语

来源: SciTech Connect

【 摘 要 】

In geological CO{sub 2} storage projects, a cap rock is generally needed to prevent CO{sub 2} from leaking out of the storage formation. However, the injected CO{sub 2} may still encounter some discrete flow paths such as a conductive well or fault (here referred to as conduits) through the cap rock allowing escape of CO{sub 2} from the storage formation. As CO{sub 2} migrates upward, it may migrate into the surrounding formations. The amount of mass that is lost to the formation is called attenuation. This report describes a simplified model to calculate the CO{sub 2} mass flux at different locations of the conduit and the amount of attenuation to the surrounding formations. From the comparison among the three model results, we can conclude that the steady-state conduit model (SSCM) provides a more accurate solution than the PMC at a given discretization. When there is not a large difference between the permeability of the surrounding formation and the permeability of the conduits, and there is leak-off at the bottom formation (the formation immediately above the CO{sub 2} plume), a fine discretization is needed for an accurate solution. Based on this comparison, we propose to use the SSCM in the rapid prototype for now given it does not produce spurious oscillations, and is already in FORTRAN and therefore can be easily made into a dll for use in GoldSim.