Method of analyzing vibrations from a drilling bit in a borehole
US4773263A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 28, 1986 |
| Grant date | Sep 27, 1988 |
| Priority date | — |
| Expiry date | Aug 28, 2006 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B44/00
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
Information on tooth wear is obtained from the frequency distribution spectrum of a vibrational quantity influenced by the impact of cutter teeth on the bottom of a bore. For example, spectra may be obtained from the product of signals indicative of torque and torsional acceleration. Tooth wear is then indicated by the shift upwardly in frequency of peaks in the spectra. Other quantities which may be used, singly or together to enhance spectral information, are weight on bit, vertical acceleration, transverse acceleration, standpipe pressure. Abrupt changes in frequency distribution curves indicate abrupt occurrences such as broken teeth or stuck cones. A stuck cone is also indicated by unidirectional peaks in a plot of torsional acceleration against time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.