Method and system for removing effects of conductive casings and wellbore and surface heterogeneity in electromagnetic imaging surveys
US7991553B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 19, 2008 |
| Grant date | Aug 2, 2011 |
| Priority date | — |
| Expiry date | Jun 11, 2029 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V3/30
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Characterizing a reservoir with electromagnetic imaging surveys includes normalizing measured voltage data by transmitter moment, sorting the normalized voltage data into common receiver profiles, densely resampling transmitter locations using common positions for the receiver profiles, coarsely resampling the data at discreet transmitter locations, defining a starting model for inversion, weighting the data by a factor, converting the normalized voltage data to ratios, calculating a conductivity image using a ratio inversion method, and verifying that an inversion has converged and the image is geologically reasonable. The image can then be displayed. The invention can be used for cross-well, surface-to-borehole, borehole-to-surface, and single-well (borehole-to-borehole) measurements measurements by which the effects of steel casing are reduced.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.