In exploration wells, the subsurface is a mystery. The NGI acts as the "first look" sensor. It confirms the top of a reservoir immediately, allowing the team to set casing faster or change drilling parameters before the bit drills too far into a problematic formation.
The NGI tool uses three scintillation detectors. BGO crystals are chosen for their high stopping power (efficiency) at high gamma ray energies. schlumberger ngi tool
Provides vertical and azimuthal resolution as fine as 0.24 inches, allowing for the identification of thin laminations and micro-fractures. Logging Speed: In exploration wells, the subsurface is a mystery