An improved elastic-tubes model for the correlation of permeability and stress with correction for the Klinkenberg effect

The correlation of permeability and stress is crucial for correctly predicting the coupled process of fluid flow and solid deformation in geophysical systems. Especially in ultra-low-permeability rocks with nanopores, the apparent permeability becomes sensitive to the properties of fluid and solid. This work presents an improved tubes model, where the correlation of permeability and stress is derived with the Klinkenberg effect correction. Both the in-situ stress effect and the Klinkenberg effect have been carefully considered in current correction of permeability prediction based on Darcy's law. The experimental data can be fitted well by the new model, and the Klinkenberg effect of gas flow in the tight porous media is successfully captured. The predictive ability of the current model has been examined as well and the results are acceptable. (C) 2017 Elsevier B.V. All rights reserved.