Gain stabilized natural gamma ray detection of casing thickness in a borehole
US4450354A · kind A · utility
28Cited by
3References
24Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 8, 1983 |
| Grant date | May 22, 1984 |
| Priority date | — |
| Expiry date | Apr 8, 2003 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V5/06
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A gain stabilized natural gamma ray spectroscopy system is used to measure casing thickness in a cased well borehole. A ratio of gamma ray intensity in two selected energy ranges forms a measurement signal representative of casing thickness based on the photoelectric absorption of natural gamma rays by iron. A coincidence technique employing dual scintillation crystals and a stabilization source of charged particles and known energy gamma rays is used for gain stabilization.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.