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The study on the reformation of dawsonite sandstones with CO2 fluids and the stratum water apartly at different temperature (100°C, 200°C and 300°C) and (100°C, 150°C and 200°C)with different CO2/H2O/sandstone system in inclosed container, indicated that the corrosion intensity of dawsonite sandstone will gradually be enhances as the temperature increasing; and in the experimental between the CO2 fluids and dawsonite sandstone, the SEM study shows that gibbsite occurs on the sample surface. at 200°C as dawsonite sandstone is being dissolved authigenic siderite forms, at 300°C, chlorite deposit on parts of the sample surface; in the experimental between the stratum water and dawsonite sandstone, the observations of SEM find that formation albite and chlorite at 200°C, analyses of spectral line of X-diffraction find that formation of unbeknown carbonate mineral at 150°C and 200°C, and generate numerical measure gradually enhances. The results revealed that: (1) The weak solution of dawsonite sandstone at 100°C and the formation of siderite at 200°C illuminate that CO2 being in carbonate in the strata can not be released when CO2 phase is adding to the system; (2) The weak solution of dawsonite sandstone at 100°C and the formation of carbonate in 100°C and 150°C show that CO2 sequestration in the forms of dawsonite or other carbonate minerals can be stable existing in the strata.
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