RE:RE:RE:RE:RE:RE:RE:RE:Good things take timeREE: Formation/Produced water is brackish containing high disolved solids (DS) plus hardness and silcates. Hardness and Silicates produce very hard scaling in steam tubes and require acid washes to remove while the remining DS if deposited in tubes are easily washed with water. Hence, Hardness and Silicates are first removed. The remaining high DS water is boiler feed water (BFW). In order to handle this water, special Once Thru Steam Generators are used which typically produce a stream of 20% water and 80% steam. The contained water flushes the steam tubes and prevents DS deposition. They are reinjected into the reservoir. This is typical SAGD.