Drill steering in high magnetic interference areas
US4909336A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 29, 1988 |
| Grant date | Mar 20, 1990 |
| Priority date | — |
| Expiry date | Sep 29, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/022
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A method for steering the direction of drilling for oil, gas, or other boreholes drilled in locations such that the level of magnetic interference from nearby magnetic materials or fields is so large that conventional methods using magnetic compass steering tools cannot meet required accuracies. The method is based upon using gyroscope-based survey tools having an inertial angular rate sensor with one or more axes of rate sensitivity and an inertial acceleration or tilt sensor with one or more axes of sensitivity to perform both the normal survey purpose for such tools and the steering function during drilling. The method includes the measurement of initial azimuthal direction, tilt angle, gyro tool face and high side tool face at the beginning of the borehole and the continuous measurement of one or more of these quantities as drilling progresses.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.