(n.) Formation Evaluation. The part of the formation that has not been affected by invasion. Syn: virgin zone. See: Annulus, Flushed Zone, Step Profile, Transition Zone
Schlumberger Ltd. (The World's Leading Supplier Of Technology, Integrated Project Management And Information Solutions to Customers Working in The Oil and Gas Industry Worldwide), Schlumberger Oilfield Glossary Cedex, France 2014. http://www.glossary.oilfield.slb.com/en/Terms/sym/ a.aspx, (Ergo - Brit) {766}