(n.) Formation Evaluation. A core taken so as to preserve the in-situ water saturation of the rock. A native-state core is usually drilled with oil-base mudor crude oil from the same reservoir. See: Fresh Core, Restored State Core, Water Saturation.
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}