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

Dual spaced epithermal neutron detector porosity logging

Patent ·
OSTI ID:4369902
An illustrative embodiment of the invention includes method and apparatus for making eanth formation porosity measurements in open or cased well boreholes. A high intensity (1.69 x 10/sup 9/ n/s) caiifornium-252 neutron source is used to irradiate earth formations surrounding a well borehole with high-energy neutrons. As the high-energy neutrtons interact with the materials comprising the earth formation their energy is reduced and some having epithermal energy are deflected back into the borehole at spaced distances from the neutron source. Two epithermal energy neutron detectors spaced at different vertical distances from the neutrton source and from each other are used to measure the epithermal neutron population at the different distances. The ratio of the counting rates in the two detectors may be interpreted in terms of eanth formation porosity by means of a predetermined relationship. (Official Gazette)
Research Organization:
Originating Research Org. not identified
NSA Number:
NSA-29-007782
Assignee:
to Texaco Inc.
Patent Number(s):
US 3774033
OSTI ID:
4369902
Country of Publication:
United States
Language:
English