Downhole clock synchronization apparatus and methods for use in a borehole drilling environment
US7230543B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 9, 2003 |
| Grant date | Jun 12, 2007 |
| Priority date | — |
| Expiry date | Oct 25, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/40
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Geophysical measurement system employed during the drilling of a well borehole. The system employs a reference clock disposed within equipment at the surface of the earth and a borehole assembly which houses a downhole clock and at least one sensor. The borehole assembly is operationally connected to a drill string, which advances the borehole. At least one synchronization shuttle apparatus containing a shuttle clock is conveyed downhole to the borehole assembly to synchronize the borehole clock with the reference clock. Reference and borehole clock synchronization is maintained at one millisecond or less over a period of days. Outputs from the reference clock and borehole clock and sensor are combined to obtain a measure of a geophysical parameter of interest. Although the measurement system is particularly applicable to seismic-while-drilling measurements, it can be used in a wide variety of clock driven geophysical measurements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.