It's more likely oil based on our 2002 330i experience. Oil filter housing gasket is suspect. Need to get it on a lift to inspect and tell for sure where its coming from which is easy to see once the car is up in the air.
Should not be a problem driving for many miles.
2014 328i Mojave Metallic
2009 328i Black Sapphire Metallic
2007 328i Black Sapphire Metallic
2007 Honda S2000 Berlina Black
(Hey Jim... am I diversified?)