Permeability (earth sciences)

About: Permeability (earth sciences) is a research topic. Over the lifetime, 15424 publications have been published within this topic receiving 288535 citations.

A note on permeability changes in geologic material due to stress

Abstract: Stress produces dramatic changes in fluid permeability of geologic materials. An increase of nearly threefold occurred in granite at high stress, an increase of 20 percent in sandstone, and a hundredfold decrease in compacted sand. Permeability of sand and sandstone did not follow the effective stress law. Flow along joints was very sensitive to effected stress changes, a fourfold change being caused by as little as 1.0 MPa.

A laboratory method to measure gas diffusion and flow in soil and other porous materials

Abstract: Summary An apparatus was constructed to measure diffusivity of krypton-85 and gas permeability in an enclosed core of soil of field structure or in other porous material. Sample enclosure decreased water loss by evaporation, reduced mass flow caused by changes in ambient temperature and pressure during diffusion measurement, and allowed subsequent measurement of gas permeability without further sample disturbance. When a bundle of tubes was used as a test sample to calibrate the apparatus, the resistances to diffusion and viscous flow agreed approximately with those calculated from the tube size and number. Gas movement was measured in dry sieved soil and in undisturbed cores of silty loam soil to illustrate the practical value of the method. In the dry cores, diffusivity relative to free air (DA/Do) was greater in ploughed soil, 0.18, than in direct drilled soil, 0.14, nearly in proportion to the greater air porosity in the ploughed soil, but air permeability in ploughed soil was four times greater than in direct drilled soil and was about 1 000 times greater than in compacted sieved soil.

Comparison of methods to calculate relative permeability from capillary pressure in consolidated water‐wet porous media

Abstract: [1] The Brooks and Corey relative permeability model has been accepted widely as a way to calculate relative permeability using capillary pressure data However, the Purcell model was found to be the best fit to the experimental data of the wetting-phase relative permeability in the cases studied here, as long as the measured capillary pressure curve had the same residual saturation as the relative permeability curve The differences between the experimental data of relative permeability and the data calculated using the Purcell relative permeability model for the wetting phase were almost negligible A physical model was developed to explain the insignificance of the effect of tortuosity on the calculation of the wetting-phase relative permeability For the nonwetting-phase, the relative permeabilities calculated using the models were very close to the experimental values in drainage except for the Purcell model However, in the case of imbibition, the relative permeabilities calculated using the models were different from the experimental data This study showed that relative permeability could be calculated satisfactorily by choosing a suitable model, especially in drainage processes In the reverse procedure, capillary pressure could also be computed once relative permeability data are available