Pre-salt is a time reference, denoting when the rock was deposited, explains Petrobras’ Breno Wolff, co-ordinator of southern coastal basin interpretation and assessment. “The reservoir materials were deposited before the salt layer and are therefore older.”
The term sub-salt is a physical designator, merely indicating that the reservoir lies below the salt layer.
“Underground salt, when subjected to high pressure and temperatures, is extremely pliable,” Wolff says, adding that the pre-salt reservoirs off Brazil are similar to those off West Africa.
