Earth formation porosity log using measurement of fast neutron energy spectrum
US4134011A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 1977 |
| Grant date | Jan 9, 1979 |
| Priority date | — |
| Expiry date | Apr 20, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V5/105
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An improved measurement of earth formation porosity is provided by the present invention using measurements of the energy spectrum of fast neutrons. A continuous source of fast neutrons is used to irradiate earth formations penetrated by a well borehole. Two neutron detectors, a fast neutron detector sensitive in the high energy range of the fast neutron energy spectrum, and an epithermal neutron detector, sensitive in the lower energy range of fast neutrons, are spaced at the same effective distance from the neutron source. Measurements of the neutron population at each detector are combined according to predetermined relationships to derive a measurement of earth formation porosity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.