In the relation Krw = kw/k, what does k represent?

In the relation Krw = kw/k, what does k represent?

• A. Dynamic permeability
• B. Pore throat size
• C. Absolute permeability of the formation
• D. Formation porosity

Answer: (C)

The key idea here is that Krw is a dimensionless fraction that tells how easily water can flow through the rock relative to the rock’s full flow capacity. The symbol k represents the rock’s absolute permeability — the intrinsic property of the formation that governs fluid flow through its pore network, independent of which fluid is present. Kw is the permeability to water at the current saturation, so the ratio Kw/k normalizes the water flow to the rock’s maximum possible flow. When the rock is fully water-saturated, Kw approaches k and Krw approaches 1. If water saturation is lower, Kw is smaller and Krw drops accordingly. Other options don’t fit because they’re not the intrinsic property used to normalize flow. Pore throat size and porosity influence permeability but are not the parameter in this normalization. Dynamic permeability isn’t the standard term here either; the equation uses the rock’s absolute permeability as the baseline.

The key idea here is that Krw is a dimensionless fraction that tells how easily water can flow through the rock relative to the rock’s full flow capacity. The symbol k represents the rock’s absolute permeability — the intrinsic property of the formation that governs fluid flow through its pore network, independent of which fluid is present.

Kw is the permeability to water at the current saturation, so the ratio Kw/k normalizes the water flow to the rock’s maximum possible flow. When the rock is fully water-saturated, Kw approaches k and Krw approaches 1. If water saturation is lower, Kw is smaller and Krw drops accordingly.

Other options don’t fit because they’re not the intrinsic property used to normalize flow. Pore throat size and porosity influence permeability but are not the parameter in this normalization. Dynamic permeability isn’t the standard term here either; the equation uses the rock’s absolute permeability as the baseline.