Sonic well logging for alteration detection
US6526354B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 1, 2001 |
| Grant date | Feb 25, 2003 |
| Priority date | — |
| Expiry date | Feb 1, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V1/44
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for determining alteration of a region of an earth formation surrounding an earth borehole, comprising the steps of providing a logging device that is moveable through the borehole; transmitting sonic energy into the formation and receiving, at a plurality of transmitter-to-receiver spacings, sonic energy that has traveled through the formation, and producing signals representative of the received sonic energy for the plurality of transmitter-to-receiver spacings; determining sonic transit times and differential transit times for the respective transmitter-to-receiver spacings; deriving a test statistic from the differential transit times; and determining the presence of alteration of a region of the formations from the test statistic. An associated apparatus for carrying out the method is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.