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U.S. Department of Energy
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Procedure and apparatus for radioactivity well logging (in Danish)

Patent ·
OSTI ID:4370289
An apparatus for conducting radioactive well logging comprising an instrument suitable for introduction through a borehole going through a number of earth formations is described. The instrument contains a fast-neutron source for irradiation of the earth formations round the borehole and a radiation in the borehole coming from the radiation source. The detector contains a proportionally working gamma radiation indicator with a multi-channel pulse height analyzer for providing output signals in at least two energy intervals, one corresponding to gamma radiation with an energy from 1.3 MeV to approx. 3.0 MeV, the other corresponding to an energy from approx. 4 MeV and upwards to comprise at least the prevalent neutron capture gamma radiation with higher energy coming from chlorine. Further the instrument contains a shield essentially surrounding the active volume of the radiation detector in the scanning instrument. The shield has a comparatively high thermal-neutron capture cross section and a characteristic neutron capture gamma radiation emission mainly within the energy interval of the first channel. The signal obtained from that channel includes a formation reference signal mainly indicating hydrogen, and the signal from the second channel a formation reference and chlorine signal mainly indicating both hydrogen nnd chlorine. (HV)
Research Organization:
Originating Research Org. not identified
NSA Number:
NSA-29-007731
OSTI ID:
4370289
Report Number(s):
DK 98872
Country of Publication:
Denmark
Language:
Danish