porosi

Porosi is a term used in geology and materials science to denote porosity, the fraction of a material's volume that consists of void spaces or pores. These pores can store or transmit fluids such as water, air, or hydrocarbons. Porosity is a dimensionless property and is often expressed as a percentage of the total volume.

Porosity comes in several forms. Primary porosity is the original pore space formed during sediment deposition or rock creation, while secondary porosity develops later through processes such as fracturing, dissolution, or weathering. A distinction is also made between total porosity, which includes all pore spaces, and effective or connected porosity, which counts only pores that are connected and able to transmit fluids. Accessible porosity refers to the portion that is connected to the pore network accessible to a given fluid.

Porosity can be estimated in several ways. It can be calculated from bulk and grain densities using the relation φ = 1 − (ρ_b / ρ_s), where φ is porosity, ρ_b is bulk density, and ρ_s is particle density. Direct measurements include helium porosimetry, gas expansion methods, and Archimedes principle. Indirect methods use borehole logs, petrophysical analyses, or imaging techniques. Porosity is influenced by grain size, sorting, packing, cementation, and diagenetic processes; clays and highly cemented rocks generally have lower porosity than well-sorted sands or fractured rocks.

In practical terms, porosi governs fluid storage and movement in natural systems and engineered materials. It is a key parameter in groundwater studies, petroleum reservoir engineering, soil science, and civil and environmental engineering, affecting water retention, filtration, and hydraulic conductivity.