Page 54 - Basic Well Log Analysis for Geologist
P. 54
THE SPONTANEOUS POTENTIAL LOG
Figure 14. Chart for determining a resistivity value for R,, from Ry...
Courtesy, Dresser Industries.
Copyright 1975, Dresser Atlas.
Given:
Rye is calculated by dividing R,, corrected to formation temperature (T,) by the ratio Ry,p/R,,.- From the exercise
example you can calculate Ry, = 0.53/5 or Ry, = 0.106. Ry at Ty = 0.53. Ty = 130°F
Procedure:
1. Locate the value of R,, on the vertical scale (in this case 0.106).
2. Follow it horizontally until it intersects the temperature curve desired (in this case 130°F between the 100° and
150° temperature curves).
3. Drop vertically from the intersection and read a value for Ry on the scale at the bottom (in this case 0.11).
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