Method of determining the difference in borehole azimuth at successive points
US4672752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 25, 1986 |
| Grant date | Jun 16, 1987 |
| Priority date | — |
| Expiry date | Apr 25, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/12
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A borehole survey instrument has a probe with a polarized light system for transmitting a signal representing the angular orientation of the probe to the surface. Light from a source in the probe is directed through a polarized filter with an axis of polarization orthogonal to the longitudinal axis of the probe. The polarized light beam is transmitted to the surface through an optical fiber light conduit. The angle of polarization is detected with a rotating polarizing filter and provides a measure of the probe orientation. In surveying a borehole, azimuth is determined from inclinometer measurements. The probe orientation in vertical sections of the borehole is measured by the polarized light system. Two measures of borehole azimuth are combined, providing an improved measure of azimuth in boreholes near vertical and near horizontal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.