Behind casing water flow detection using continuous oxygen activation
US4032780A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 3, 1975 |
| Grant date | Jun 28, 1977 |
| Priority date | — |
| Expiry date | Nov 3, 1995 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V5/101
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Measurement of the volume flow rate and linear flow velocity of undesired behind casing water flow is provided. A well tool having a 14 MEV neutron source is used to continuously irradiate earth formations behind well casing. The continuous neutron irradiation activates elemental oxygen nuclei comprising the molecular structure of any undesired water flow to be detected. Dual spaced gamma ray detectors located above or below the neutron source detect the decay of unstable isotope nitrogen 16 and from these indications the linear flow velocity of the undesired water flow is deduced. By then estimating the distance R to the undesired flow region the volume flow rate V may be deduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.