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U.S. Department of Energy
Office of Scientific and Technical Information

Radioactivity well logging methods and apparatus

Patent ·
OSTI ID:4340113
An illustrative embodiment of the invention compensates neutron measurements of the porosity of an earth formation for sudden changes in borehole diameter. Typically, a sidewall porosity logging tool for transport through a borehole is equipped with two neutron detectors spaced at different distances from the neutron source. In order to improve the vertical resolution of the tool, a circuit stores the signal from the longspaced detector until the shorter spaced detector has traversed a distance along the borehole wall that is equal to the separation between the two detectors. This memory feature adjusts the porosity signals to a common zone of observation. These apparent porosity signals then are combined with borehole caliper signals to compensate for the effect of changes in borehole diameter. (Official Gazette)
Research Organization:
Originating Research Org. not identified
NSA Number:
NSA-29-015773
Assignee:
to Schlumberger Technology Corp.
Patent Number(s):
US 3784822
OSTI ID:
4340113
Country of Publication:
United States
Language:
English

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