Figure 3
From: Experimental Study of Cement - Sandstone/Shale - Brine - CO2Interactions
ESEM images of reacted sandstone. (A) Unreacted sandstone consisted of quartz, carbonate cement, and chlorite which lines the pore spaces. Reaction of sandstone with CO2-rich brine produced (B) aluminum hydroxide or aluminosilicate reaction products deposited on the sandstone surface and (C-D) coagulated Si-rich and Fe-rich precipitates in the brine. Reaction of the sandstone with cement and CO2-rich brine produced (E) Fe - bearing CaCO3 precipitates.