Borehole logging methods for detection and imaging of formation structural features
US4817059A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 26, 1987 |
| Grant date | Mar 28, 1989 |
| Priority date | — |
| Expiry date | Jun 26, 2007 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/50
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Waveform data obtained in a borehole by a tool having a sonic source and an array of sonic detectors is analyzed to obtain an image of formation features within several tens of feet of the borehole, such as fractures, bed boundaries and other boreholes. A value of background sonic slowness is derived from the data and used to determine the sonic energy transit time from the source to each detector via each point in a grid of points extending into the formation and along the borehole. The time for a particular detector/point pair is used to extract the amplitude of the waveform from that detector at that time relative to operation of the source. Such amplitudes for the same point and for different detectors and tool positions are cumulated. The final values for all points are plotted as a variable density display which provides the desired image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.