Geochemical logging apparatus and method for determining concentrations of formation elements next to a borehole

Patent · Tue Jun 04 04:00:00 EDT 1991

OSTI ID:5682790

Roscoe, B; Grau, J

This paper describes a method for identifying and determining the concentrations of subsurface formation elements, next to a borehole. It comprises: irradiating the formations with neutrons from a energy neutron source disposed in a logging tool lowered in the borehole, the neutron source being the only neutron source disposed in the the logging tool; and counting the delayed gamma rays resulting from the activation of atoms of at least of a first element by the neutrons emitted by the source; deducing from the counts of activation gamma rays the concentration of the first element; detecting and counting the prompt gamma rays resulting from the capture of the neutrons emitted by the source by atoms of at least a second element; and deducing from the count rates of capture gamma rays the concentration of the second element.

• Assignee: Schlumberger Technology Corp., Houston, TX (USA)
• Patent Number(s): US 5021653; A
• Application Number: PPN: US 7-463223
• OSTI ID: 5682790
• Country of Publication: United States
• Language: English

Related Subjects

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47 OTHER INSTRUMENTATION
CHEMICAL COMPOSITION
EQUIPMENT
GEOCHEMICAL SURVEYS
GEOLOGIC FORMATIONS
NEUTRON LOGGING
NEUTRON-GAMMA LOGGING
RADIOACTIVITY LOGGING
RESERVOIR ROCK
SURVEYS
WELL LOGGING
WELL LOGGING EQUIPMENT