| US 7,565,244 B2 | ||
| Method and system for removing effects of conductive casings and wellbore and surface heterogeneity in electromagnetic imaging surveys | ||
| David Alumbaugh, Berkeley, Calif. (US); Ping Zhang, Albany, Calif. (US); Edward Nichols, Berkeley, Calif. (US); Frank Morrison, Berkeley, Calif. (US); Aria Abubakar, North Reading, Mass. (US); and Tarek Habashy, Burlington, Mass. (US) | ||
| Assigned to Schlumberger Technology Corporation, Sugar Land, Tex. (US) | ||
| Filed on Jun. 27, 2007, as Appl. No. 11/768,975. | ||
| Prior Publication US 2009/0005992 A1, Jan. 01, 2009 | ||
| Int. Cl. G01V 1/40 (2006.01) | ||
| U.S. Cl. 702—6 [702/7; 702/11; 324/323; 324/334; 324/339; 367/29; 367/49] | 21 Claims |
| 1. A method for characterizing a reservoir, comprising the steps of:
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 common receiver profiles;
coarsely resampling the normalized voltage data at discrete transmitter locations;
defining a starting model for inversion;
weighting the normalized voltage 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.
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