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.

Transverse permeability of fibrous porous media

Abstract: In this study, the transverse permeability of fibrous porous media is studied both experimentally and theoretically. A scale analysis technique is employed for determining the transverse permeability of various fibrous matrices including square, staggered, and hexagonal arrangements of unidirectionally aligned fibers, as well as simple two-directional mats and simple cubic structures. In the present approach, the permeability is related to the porosity, fiber diameter, and tortuosity of the medium. In addition, the pressure drop in several samples of tube banks of different arrangements and metal foams are measured in the creeping flow regime. The pressure-drop results are then used to calculate the permeability of the samples. The developed compact relationships are successfully verified through comparison with these experimental results and the data reported by others. Our results suggest that fiber orientation has an important effect on the permeability; however, these effects are more pronounced in low porosities, i.e., ɛ<0.7.

The effect of the capillary number and its constituents on two-phase relative permeability curves

Abstract: The goal of this study is to determine the effect of the capillary number on two-phase (oil-water) relative permeability curves Specifically, a series of steady-state relative permeability measurements were carried out to determine if the capillary number causes changes in the two-phase permeabilities or if any one of its constituents, such as flow velocity, fluid viscosity, or interfacial tension, are the controlling variables For the core tests, run in fired Berea sandstone, a Soltrol 170 oil-calcium chloride brine-isopropyl alcohol-glycerin system was utilized Alcohol was the interfacial tension reducer and glycerin was the wetting phase viscosifier The non-wetting phase (oil) relative permeability showed little correlation with the capillary number As the interfacial tension decreased below 20 dynes/cm, the oil permeability increased dramatically However, as the wetting phase viscosity increased, the non-wetting phase demonstrated less ability to flow For the wetting phase (water) relative permeability, the opposite capillary number effect was shown For both the tension decrease and the viscosity increase, ie, a capillary number rise, the water permeability increased, but not as much as with the oil curves No velocity effects were noted for the range studied A relative permeability model was then developed from the experimental data, based on fluidmore » saturations, interfacial tension, fluid viscosities, and the residual saturations, using regression analysis The applicability of these regression models were then tested with the aid of a two-phase reservoir simulator« less

Classification and characterizations of biogenically enhanced permeability

Abstract: Recent research shows that ichnology has significant application to production geology. As such, permeability enhancement in bioturbated media has been recognized in five interrelated scenarios: (1) surface-constrained textural heterogeneities; (2) nonconstrained textural heterogeneities; (3) weakly defined textural heterogeneities; (4) diagenetic textural heterogeneities; and (5) cryptic bioturbation.Our data demonstrate that substrate-controlled ichnofossil assemblages can enhance the permeability and vertical transmissivity of an otherwise relatively impermeable matrix. Permeability enhancement develops when burrows excavated into a firm ground are filled with a contrasting sediment from the overlying strata. Fill contrasting with the encasing firm-ground substrate leads to anisotropic porosity and permeability. The same concept can be applied to carbonate reservoirs, where burrow fills are subjected to different diagenetic phases. This may also lead to anisotropic porosity and permeability that can have dramatic effects on reserve calculations.If the burrow fills have enhanced permeability but burrow effects are not recognized, reserve calculations will be too low. Likewise, if the burrow fills have reduced permeability, the reserve calculations may be too high. Understanding the flow dynamics of the resulting anisotropic permeability provides a potentially powerful reservoir-development tool. The implications are far reaching, particularly pertaining to calculations of reserves and their deliverability.