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http://dx.doi.org/10.7582/GGE.2015.18.3.125

Suggestion of the Modified Archie's Formula for Calculating Water Saturation of Clean Sandstone and Carbonate Rocks  

Lee, Sang-Hee (Energy and Mineral Resources Dept., Dong-A University)
Ko, Eun-Ji (Dongnam Regional Infrastructure Tech. Management Center)
Kim, Jin-Hoo (Energy and Mineral Resources Dept., Dong-A University)
Publication Information
Geophysics and Geophysical Exploration / v.18, no.3, 2015 , pp. 125-132 More about this Journal
Abstract
The water saturation ($S_w$), which is very important to estimate hydrocarbon reserves in the reservoir, has been determined from resistivity index (RI) by using the Archie's formula. However, in many cases, it has been reported that n is not constant for a given formation and it could be varied with water saturation. In addition, it frequently happens that the line obtained by linear regression analysis on log-log scale does not pass through the origin. In order to overcome these drawbacks, we suggested a modified Archie's formula, which can handle almost all the RI vs. $S_w$ cross-plots whether the trend is straight or curved and whether it passes through the origin or not. We also demonstrated that how to determine conductivity exponent ${\mu}$, critical water saturation $S_c$, and saturation distribution factor b in the laboratory to use the modified Archie's formula. Since the modified Archie's formula takes into account pore structure, pore water distribution, and wettability of reservoir such as clean sandstone and carbonate rocks, it might improve field applicability.
Keywords
Resistivity index (RI); Water saturation ($S_w$); Modified Archie's formula; Saturation exponent (n);
Citations & Related Records
Times Cited By KSCI : 4  (Citation Analysis)
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