Distributed measurement of minimum and maximum in-situ stress in substrates
US11022717B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Aug 28, 2018 |
| Grant date | Jun 1, 2021 |
| Priority date | — |
| Expiry date | Sep 1, 2038 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/4735
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for performing distributed measurements of in-situ stress includes an expandable element with at least one fiber optic sensor. The expandable element can be positioned at various depths in a hole in a substrate. A pressurizing device expands (and contracts) the expandable element when the expandable element is inserted in the hole in the substrate to exert pressure on the hole wall. A pressure sensor provides a sensor output indicative of a pressure applied to the hole wall by the expandable element. The fiber optic sensor and an optical interrogator measure strain along a length of the sensor in a continuous, high spatial resolution manner Based on the measured strain and pressure sensor output, the system determines various properties of the substrate such as, minimum principal stress, maximum principal stress, and/or principal stress direction associated with one or more fractures in the substrate, as well as substrate modulus.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.