ANTENNA CORE MATERIAL FOR USE IN MWD RESISTIVITY MEASUREMENTS AND NMR MEASUREMENTS

摘要

The present invention provides a novel use of a material having a high internal magnetostrictive damping and/or using material wi th explicitly low magnetostriction as an antenna core material for NMR and resistivity devices in a borehole. The probe stuctural geometry facilitates the use of material, which has a relatively low magnectic permeability.