Gas reservoirs with low permeability (k<0.1 mD) are among the unconventional reservoirs and are commonly termed as "Tight Gas Reservoirs". In conventional gas reservoirs that have high permeability, the flow of gas is basically controlled by the reservoir permeability and it is calculated using the Darcy equation. In these reservoirs, gas flow due to gas diffusion is ignored compared to Dar...

The first direct measurements of effective magnetic diffusivity in turbulent flow of electroconductive fluids (the so-called β effect) under the magnetic Reynolds number Rm≫1 are reported. The measurements are performed in a nonstationary turbulent flow of liquid sodium, generated in a closed toroidal channel. The peak level of the Reynolds number reached Re≈3×10(6), which corresponds to the ma...

The dispersion of passive scalar by Stokes flow through a dilute suspension of solid spheres fixed at random points in space is a basic model of mixing and transport in an unconsolidated porous medium. Earlier investigators have used a general theory of macroscopic transport to calculate the Lagrangian velocity autocorrelation function and the effective diffusivity of this system. If the tracer...

The robustness of Nakamura’s effective diffusivity diagnostic for quantifying eddy diffusivities of tracers in a streamwise-average framework is carefully examined in an oceanographic context and the limits of its applicability are detailed. The nearsurface Southern Ocean geostrophic flow, obtained from altimetric observations, is chosen for particular examination. The temporal variability of t...