This is defined as the ability of a rock to transmit fluid through pore spaces.

This is defined as the ability of a rock to transmit fluid through pore spaces.

• A. Porosity
• B. Permeability
• C. Capillarity
• D. Percolation

Answer: (B)

Permeability is the rock property that describes how easily a fluid can move through the interconnected pore spaces. It isn’t just about how much empty space exists (porosity); it’s about whether those voids form a connected network that allows fluids to flow. A rock can have high porosity but low permeability if the pores are isolated or poorly connected, which inhibits flow. Permeability depends on pore throat size, connectivity, and the arrangement of grains, with larger, well-connected pathways letting fluids pass more readily. In practical terms, permeability governs the flow rate under a given pressure and fluid viscosity, as captured in Darcy’s law. Capillarity concerns how fluids rise or are retained in tiny pores due to surface tension and capillary pressure, which is related to pore size but describes wetting effects rather than the overall ability to transmit fluid through the rock. Percolation describes the process or threshold of fluid finding a continuous path through the material, not a static property that measures flow capacity. For example, sandstone typically transmits fluids more readily than shale because of better pore connectivity, leading to higher permeability.

Permeability is the rock property that describes how easily a fluid can move through the interconnected pore spaces. It isn’t just about how much empty space exists (porosity); it’s about whether those voids form a connected network that allows fluids to flow. A rock can have high porosity but low permeability if the pores are isolated or poorly connected, which inhibits flow. Permeability depends on pore throat size, connectivity, and the arrangement of grains, with larger, well-connected pathways letting fluids pass more readily. In practical terms, permeability governs the flow rate under a given pressure and fluid viscosity, as captured in Darcy’s law. Capillarity concerns how fluids rise or are retained in tiny pores due to surface tension and capillary pressure, which is related to pore size but describes wetting effects rather than the overall ability to transmit fluid through the rock. Percolation describes the process or threshold of fluid finding a continuous path through the material, not a static property that measures flow capacity. For example, sandstone typically transmits fluids more readily than shale because of better pore connectivity, leading to higher permeability.