| 摘要 |
A gamma-gamma density logging tool employs a gamma-ray source and a pair of gamma-ray detectors. A first detector receives only natural gamma rays from the formations surrounding the borehole. A second detector receives both natural gamma rays and scattered gamma rays from the formations surrounding the borehole. The count rate from the second detector is modified by the count rate of the first detector to provide for a density measurement that is corrected for the effects of natural gamma radiation from radioactive ore-bearing zones in the formations.
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