Changes

==Nonreservoir pore geometry and pore type==

==Nonreservoir pore geometry and pore type==

In contrast to the vuggy packstone facies, the porous mudstone facies displays poor permeability (5 md or less), even though porosity can be as high as 30% (points 1 and 5, group B in Figure 9-102). This is because the porosity is pinpoint vugs isolated within fine intercrystalline meso- to microporosity formed by silt-sized (10μ or less) dolomite rhombs. Capillary pressure and SEM data indicate the pore throats are less than 1μ in radius, with an abundance of pore throats about 0.5μ in radius or smaller (see Figure 9-100). Port size puts much of this rock in micropore type. While localized lenses of porous mudstone have as much as 30% porosity and 20 md permeability, these probably are laterally isolated from each other.

In contrast to the vuggy packstone facies, the porous [[mudstone]] facies displays poor permeability (5 md or less), even though porosity can be as high as 30% (points 1 and 5, group B in Figure 9-102). This is because the porosity is pinpoint vugs isolated within fine intercrystalline meso- to microporosity formed by silt-sized (10μ or less) dolomite rhombs. [[Capillary pressure]] and SEM data indicate the pore throats are less than 1μ in radius, with an abundance of pore throats about 0.5μ in radius or smaller (see Figure 9-100). Port size puts much of this rock in micropore type. While localized lenses of porous mudstone have as much as 30% porosity and 20 md permeability, these probably are laterally isolated from each other.

==See also==

==See also==