The procedure for determining ''R''<sub>w</sub> from the resistivity ratio method is outlined as follows. The data that are required include ''R''<sub>t</sub> from ILd or LLd, ''R''<sub>xo</sub> from SFL or another shallow-reading resistivity device, ''R''<sub>mf</sub>, and ''T''<sub>f</sub>. | The procedure for determining ''R''<sub>w</sub> from the resistivity ratio method is outlined as follows. The data that are required include ''R''<sub>t</sub> from ILd or LLd, ''R''<sub>xo</sub> from SFL or another shallow-reading resistivity device, ''R''<sub>mf</sub>, and ''T''<sub>f</sub>. |