Well logging detector with decoupling optical interface
US4900937A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 20, 1988 |
| Grant date | Feb 13, 1990 |
| Priority date | — |
| Expiry date | Oct 20, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/017
- WIPO fieldEnvironmental technology
- WIPO sectorChemistry
Abstract
A well logging detector includes an elongated scintillation crystal having one end biased against and optically coupled to a transparent window portion of the detector housing. The biasing force on the crystal is provided by a compression spring located at and bearing against the other end of the crystal. The biasing force applied to the crystal by the spring is weak enough to allow the crystal to move away from and optically decouple from the window portion in response to shock forces on the detector. Subsequent to such shock induced decoupling, the biasing spring moves the crystal against the window portion to re-establish optical coupling therebetween. Such a biasing structure precludes excessive axial loading of the crystal by shock forces tending to move the crystal against the window as opposed to away from it. Such a shock resistant detector is especially well suited to measurement-while-drilling (MWD) applications.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.