In-situ equivalent CO sub 2 estimates using a neutron-induced gamma-ray spectroscopy logging system

Conference · Fri Sep 01 00:00:00 EDT 1989

OSTI ID:5721657

Hearst, J. R.; Conaway, J. G.; Mathews, M. A.; Barber, J. W. ^[1]

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1. Lawrence Livermore National Lab., CA (USA)

We are trying to adapt a commercial neutron-induced gamma-ray spectroscopy log to estimate carbonate content in emplacement (2- 4-m diameter) boreholes at the Nevada Test Site. Such a log would test a much larger (and therefore presumably more representative) sample than the few grams currently used in sample analysis and would be continuous rather than discrete. We have performed large-scale laboratory experiments using test boxes filled with mixtures of silica sand and crushed limestone. The test boxes are 5 m long, and the material is screeded into a cylindrical arc of 1.2-m radius to simulate our borehole environment. These tests showed that the log is sensitive not only to carbonate content but also to water content of the formation as well as the gap between the logging sonde and the wall of the borehole. Consequently, we modified the sonde to measure the sonde-wall gap and developed procedures for correcting the measured carbonate content for water content and gap. When we used these procedures in the laboratory, with a moving sonde and a rough (3- 8-cm variations) surface on the test mixture, we obtained an accuracy of better than 0.02 equivalent dry weight fraction CO{sub 2} (the amount of CO{sub 2} that would be generated if all the carbonate were converted to CO{sub 2}). 14 refs., 15 figs.

• Research Organization: Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
• Sponsoring Organization: DOE/DP
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5721657
• Report Number(s): UCRL-100795; CONF-8909163-5; ON: DE90001024
• Resource Relation: Conference: 5. symposium on containment of underground nuclear detonations, Santa Barbara, CA (USA), 19-21 Sep 1989
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
CARBON DIOXIDE
PRODUCTION
UNDERGROUND EXPLOSIONS
DETECTION
WELL LOGGING
MODIFICATIONS
GAMMA SPECTROSCOPY
NEVADA TEST SITE
NUCLEAR EXPLOSIONS
PORTABLE EQUIPMENT
ROCKS
CARBON COMPOUNDS
CARBON OXIDES
CHALCOGENIDES
EQUIPMENT
EXPLOSIONS
NATIONAL ORGANIZATIONS
OXIDES
OXYGEN COMPOUNDS
SPECTROSCOPY
US DOE
US ORGANIZATIONS
450300* - Military Technology
Weaponry
& National Defense- Nuclear Explosion Detection