Inferring Relative Permeability from Resistivity Well Logging

Abstract

It is difficult to measure steam-water relative permeability because of mass transfer and phase transformation as pressure changes. It would be helpful for engineers and scientists to have a method to infer steam-water relative permeability from resistivity data because it is easier to measure.

On the other hand, there are a great amount of resistivity data available from well logging. However such models have been few. In this study, a semi-analytical model was developed to infer relative permeability from resistivity data and was tested against experimental data.

The results demonstrated that the relative permeability calculated using the new model with resistivity data was closely equal to those calculated from capillary pressure data and the measured data. The model developed in this study also provides an approach to estimate relative permeability from the resitivity data by well logging. Routine well testing can provide the effective permeability of rock.

Therefore the absolute permeability of rock around well bore may be estimated using the relative permeability inferred from well logging and the effective permeability from well test. This provides a solution to the challenge, which has been a long time, of evaluating permeability from production test.