Method of identification of well damage and downhole irregularities
US5081613A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 27, 1988 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | Sep 27, 2008 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE21B47/006
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method of testing a water or petroleum well to obtain information about well features, especially that part of the well beneath the ground surface, is described. The method is especially useful in detecting problems or irregularities in the well such as stuck tools, casing damage, damaged zones in an uncased well, or debris in a well. The method involves creating oscillations in the fluid pressure in the well. Transducers measure the pressure oscillations. The measured pressure oscillations are used to determine resonant frequencies. The measured resonant frequencies are used to determine the characteristic impedance and the depth of each reflector in the well, after removing resonances caused by known reflectors. It is then possible to determine the nature of each unknown reflector based on suspected problems or the well's operational history.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.