What is the lowest possible porosity for uniform sphere packings?
0.36
The minimum bulk porosity of sphere packings is 0.36 (for uniform-sized spheres), and the values for real packings typically fall into the range e = 0.36-0.42.
How does packing affect porosity?
In general, larger particles cannot pack together as well as smaller particles can, which means that packing larger particles together leaves more space for air to fill between the particles.
What is Moldic porosity?
1. n. [Geology] A type of secondary porosity created through the dissolution of a preexisting constituent of a rock, such as a shell, rock fragment or grain. The pore space preserves the shape, or mold, of the dissolved material.
What is vuggy porosity?
Vuggy porosity is gas- or fluid-filled openings in rock matrix that are large enough to be seen with the unaided eye. Well-connected vugs can form major conduits for flow of ground water, especially in carbonate rocks.
What is intercrystalline porosity?
Intercrystalline Porosity. This type of porosity is formed in the existing space among the dolomite crystals (Figure 3(a)) and their geological origin is from sabkha to open marine. This porosity is one of the best spaces for gas reserves in the gas field.
How is vuggy porosity formed?
vuggy porosity A form of secondary porosity in which the pore spaces are formed by solution vugs.
What is intraparticle porosity?
The Inter-particle porosity are the large pores between particles while the Intra-particle porosity are the smaller pores within the particle.
What is a rhombohedral lattice system?
It is a special case of a parallelepiped where all edges are the same length. It can be used to define the rhombohedral lattice system, a honeycomb with rhombohedral cells.
When is the amount of porosity the highest?
Porosity is highest when materials are loosely packed and grains are uniform in size and shape. As a thought experiment, consider two identical rooms (e.g., same total volume), one full of glass spheres the size of soccer balls and one full of 1 cm diameter spherical glass marbles.
How does porosity change with depth?
Additional loss of porosity occurs when sediments and rocks are overlain by thicker packages of earth materials. For example, Helm (1982) found porosities decreased by 25 to 50% within the first 1000 to 2000 m of burial and continued to decrease at greater depths (up to 75% at 3000 m depths).
Which materials have no primary porosity when formed?
Many of Earth’s rock materials have little to no primary porosity when formed. That is, there is little to no void space in the material when it is first formed.