Preliminary Simulations of CO2 Transport in the Dolostone Formations in the Ordos Basin, China

Hao, Y ; Wolery, T ; Carroll, S

关键词: ANHYDRITE;    BRINES;    CARBONATE MINERALS;    CARBONATES;    CHINA;    DISSOLUTION;    DISTRIBUTION;    GEOLOGY;    PERMEABILITY;    POROSITY;    PRECIPITATION;    SIMULATION;    SPATIAL DISTRIBUTION;    STORAGE;    TRANSPORT;   

DOI  :  10.2172/952430
RP-ID  :  LLNL-TR-412701
PID  :  OSTI ID: 952430
Others  :  TRN: US200913%%615

学科分类：地球科学(综合)

美国|英语

来源: SciTech Connect

【 摘 要 】

This report summarizes preliminary 2-D reactive-transport simulations on the injection, storage and transport of supercritical CO{sub 2} in dolostone formations in the Ordos Basin in China. The purpose of the simulations was to evaluate the role that basin heterogeneity, permeability, CO{sub 2} flux, and geochemical reactions between the carbonate geology and the CO{sub 2} equilibrated brines have on the evolution of porosity and permeability in the storage reservoir. The 2-D simulation of CO{sub 2} injection at 10{sup 3} ton/year corresponds to CO{sub 2} injection at a rate of 3 x 10{sup 5} ton/year in a 3-D, low permeable rock. An average permeability of 10 md was used in the simulation and reflects the upper range of permeability reported for the Ordos Basin Majiagou Group. Transport and distribution of CO{sub 2} between in the gas, aqueous, and solid phases were followed during a 10-year injection phase and a 10-year post injection phase. Our results show that CO{sub 2} flux and the spatial distribution of reservoir permeability will dictate the transport of CO{sub 2} in the injection and post injection phases. The injection rate of supercritical CO{sub 2} into low permeable reservoirs may need to be adjusted to avoid over pressure and mechanical damage to the reservoir. Although it should be noted that 3-D simulations are needed to more accurately model pressure build-up in the injection phase. There is negligible change in porosity and permeability due to carbonate mineral dissolution or anhydrite precipitation because a very small amount of carbonate dissolution is required to reach equilibrium with respect these phases. Injected CO{sub 2} is stored largely in supercritical and dissolved phases. During the injection phase, CO{sub 2} is transport driven by pressure build up and CO{sub 2} buoyancy.