Calibration of a neutron log in partially saturated media

Conference · Fri Nov 03 04:00:00 EST 1978

OSTI ID:6163936

Hearst, J R

An epithermal neutron logging sonde has been calibrated in a facility containing nine samples. Each sample represents a different combination of bulk density and water content. The facility simulates very large (approximately 2-m-diameter) dry holes and 30-cm-diameter dry and water-filled holes. The neutron log data are affected not only by water content, but also by bulk density and the gap between the sonde and the wall of a dry borehole. For large holes and the wet 30-cm hole, count rate generally decreases with increasing bulk density. For the dry 30-cm hole, however, the count rate increases with increasing density. Algorithms for fitting count rate to water content, density, and gap have been developed for a shielded and unshielded logging sonde. By using this algorithm, it is possible for the first time to log for water content in dry holes in partially saturated media and obtain good agreement with sample data.

• Research Organization: California Univ., Livermore (USA). Lawrence Livermore Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 6163936
• Report Number(s): UCRL-81657; CONF-790605-3
• Country of Publication: United States
• Language: English

Related Subjects

440400* -- Well Logging Instrumentation
47 OTHER INSTRUMENTATION
ALGORITHMS
BARYONS
CALIBRATION
ELEMENTARY PARTICLES
EPITHERMAL NEUTRONS
EQUIPMENT
FERMIONS
HADRONS
MATHEMATICAL LOGIC
NEUTRON LOGGING
NEUTRON-NEUTRON LOGGING
NEUTRONS
NUCLEONS
RADIOACTIVITY LOGGING
WATER SATURATION
WELL LOGGING
WELL LOGGING EQUIPMENT