Optical fiber based downhole seismic sensor systems and methods
US9075155B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 8, 2011 |
| Grant date | Jul 7, 2015 |
| Priority date | — |
| Expiry date | Aug 26, 2032 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/1234
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Various optical fiber-based seismic monitoring system embodiments include a light source that drives an optical fiber positioned within a borehole. At least one light sensor analyzes Rayleigh backscattered light to obtain an acoustic signal for each of multiple points along the borehole. One or more processors operate to determine microseismic event direction, distance, and/or intensity based at least in part on phase information of said acoustic signals. The acoustic signal cross-correlations, semblances, or phase-sensitive similarity measures can be determined as a function of scanning direction to accurately determine the relevant microseismic event information. The optical fiber may be positioned in the cemented annulus of a cased borehole having a shape that extends along more than one dimension (e.g., an L-shaped borehole).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.