Thermal and Epithermal Neutron Measurement for Porosity Analysis
The CNL compensated neutron log tool contains a radioactive source that bombards the formation with fast neutrons. These neutrons are slowed and then captured, primarily by hydrogen atoms in the formation. The slowed neutrons deflected back to the tool are counted by detectors. Because the tool responds primarily to the hydrogen content of the formation, the measurements are scaled in porosity units. Both epithermal (intermediate) neutrons and thermal (slow) neutrons can be measured depending on the detector design.
The CNT-H tool uses two thermal detectors for a borehole-compensated thermal neutron measurement. The CNT-G dual-energy neutron log (DNL) tool has two thermal and two epithermal detectors and provides separate energy measurements for gas detection and improved reservoir descriptions. The epithermal measurement can be made in air- or gas-filled holes.
CNL tools are combinable and are usually run simultaneously with other services.
Principal applications - Porosity analysis
- Lithology identification
- Clay analysis
- Gas detection
Request More Information
|