Wireline-derived gas saturations are usually obtained through an interpretation of resistivity logs. The resistivity log interpretation is severely affected by the "excess conductivity" due to clays. One approach utilizes clay mineralogy derived from wireline interpretation to compute cation exchange capacity to estimate the excess conductivity due to clays. The second approach involves direct measurement of the membrane potential in shaly sands which can then be used to calculate a clay conductivity.

A quantitative wireline estimate of permeability versus depth is needed in hydrocarbon-bearing formations to make set pipe decisions in the field. Wireline-derived permeability is of specific importance in tight gas reservoirs because the traditional methods are difficult to implement in this fragile environment. The first wireline method is based on the quantification of mineralogy in the formation. The second estimates absolute permeability from resistivity logs using core-based correlation between specific surface area and bulk fluid volumes.