TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Barents Sea is an environmentally important ecosystem defined as part of the Arctic. The Norwegian environmental regulation is particular strict for this area, a zero discharge regime prevails. This paper describes the challenges of entering the area for exploration drilling. With reference to a recent operation (2005) a presentation of how the challenges were resolved is given. New procedures and new techniques were implemented to achieve compliance with performance expectations. The succeeding experience lead to important learning that has implications for future exploration drilling in such areas.