Core Gamma Logger
LWD
Halliburtonā€˜s Core Gamma Logger (CGL) helps enable operators to make quick, real-time decisions about coring, testing and well completion activities immediately after the core has arrived on surface. This proven technology offers the most accurate gamma log in the business, allowing excellent correlation and depth shift when necessary to correlate precisely with the wellbore gamma log.

For more specifications:
http://www.halliburton.com/en-US/ps/drill-bits/coring/surface-processing-and-handling/default.page?node-id=hgyyxr33