Translations:Dictionary:Archie’s formulas/6/en

• a = proportionality constant varying from 0.6 to 1.5,
• m = cementation factor that varies between 1.3 and 3,
• n = saturation exponent, often assumed to be 2,
• R_o = resistivity of the formation when 100% saturated with formation water,
• R_w = resistivity of the formation water,
• R_t = true resistivity of the formation.