Figure 5
From: Experimental Study of Cement - Sandstone/Shale - Brine - CO2Interactions
ESEM images of reacted shale. (A) Unreacted shale consisted of fine-grained quartz, illite, and carbonate. When the shale was reacted with CO2-rich brine (B) submicron reaction products deposited on the shale surface and in solution. When the shale reacted with cement and the CO2-rich brine (C-D) there was extensive clay dissolution and precipitation of smectite and calcium carbonate.