| US 7,573,027 B2 | ||
| Measurement of standoff corrected photoelectric factor | ||
| Cornelis Huiszoon, Houston, Tex. (US) | ||
| Assigned to Baker Hughes Incorporated, Houston, Tex. (US) | ||
| Filed on Jul. 20, 2007, as Appl. No. 11/780,993. | ||
| Claims priority of provisional application 60/849281, filed on Oct. 04, 2006. | ||
| Prior Publication US 2008/0083872 A1, Apr. 10, 2008 | ||
| Int. Cl. G01V 5/08 (2006.01); G01V 5/12 (2006.01) | ||
| U.S. Cl. 250—269.1 [250/269.3] | 20 Claims |
| 1. A method of estimating a photoelectric factor (PEF) of an earth formation, the method comprising:
(a) irradiating the earth formation from within a borehole;
(b) measuring gamma ray counts resulting from the irradiating using a detector;
(c) estimating a first value of the PEF using the measured gamma ray counts within a first hard spectral window and a first
soft spectral window and a second value of the PEF using the measured gamma ray counts within a second hard spectral window
and a second soft spectral window;
(d) estimating a first corrected value of the PEF using a difference between the estimated first value of the PEF and the
estimated second value of the PEF; and
(e) recording the estimated first corrected value of the PEF on a suitable medium.
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